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Sample records for desulfurization sorbent quarterly

  1. Hot coal gas desulfurization with manganese based sorbents. Quarterly report, June--September 1994

    SciTech Connect

    Hepworth, M.T.; Slimane, R.B.

    1994-11-01

    The focus of work being performed on hot coal gas desulfurization at the Morgantown Energy Technology Center is primarily in the use of zinc titanate sorbents; however, prior studies indicated that an alternate sorbent, manganese dioxide-containing ore in mixture with alumina (75 wt% ore + 25 wt% Al{sub 2}O{sub 3}) appears to be a strong contender to zinc-based sorbents. Manganese, for example, has a lower vapor pressure in the elemental state than zinc; hence, it is not as likely to undergo zinc-depletion from the sorbent surface upon loading and regeneration cycles. Also manganese oxide is less readily reduced to the elemental state than iron; hence, the range of reduction potentials for oxygen is somewhat greater than for zinc ferrite. In addition, thermodynamic analysis of the manganese-oxygen-sulfur system shows it to be less amenable to sulfation than zinc ferrite. Also manganese chlorides are much less stable and volatile than zinc chlorides. Potential also exists for utilization of manganese at higher temperatures than zinc ferrite or zinc titanate. This Eighth Quarterly Report documents progress in pelletizing and testing via thermo-gravimetric analysis of individual pellet formulations of manganese ore/alumina combinations and also manganese carbonate/alumina with two binders, dextrin and bentonite.

  2. Hot coal gas desulfurization with manganese-based sorbents. Quarterly report, October--December 1993

    SciTech Connect

    Hepworth, M.T.; Slimane, R.B.

    1994-01-01

    The focus of work being performed on Hot Coal Gas Desulfurization at the Morgantown Energy Technology Center is primarily in the use of zinc ferrite and zinc titanate sorbents; however, prior studies indicated that an alternate sorbent, manganese dioxide-containing ore in mixture with alumina (75 wt% ore + 25 wt% Al{sub 2}O{sub 3}) may be a viable alternative to zinc-based sorbents. Manganese, for example, has a lower vapor pressure in the elemental state than zinc hence it is not as likely to undergo depletion from the sorbent surface upon loading and regeneration cycles. Also manganese oxide is less readily reduced to the elemental state than iron hence the range of reduction potentials for oxygen is somewhat greater than for zinc ferrite. In addition, thermodynamic analysis of the manganese-oxygen-sulfur system shows it to be less amenable to sulfation than zinc ferrite. Potential also exists for utilization of manganese at higher temperatures than zinc ferrite or zinc titanate. This Fifth Quarterly Report documents progress in pellet testing via thermogravimetric analysis of pellet formulation FORM4-A of a manganese ore/alumina combination. This formulation, described more fully in the Quarterly Technical Progress Report of October 15, 1993, consists of manganese carbonate combined with alundum. A 2-inch fixed-bed reactor has been fabricated and is now ready for subjecting pellets to cyclic loading and regeneration; however, a minor problem has arisen during the regeneration cycle in that sulfur tends to form and plug the exit tube during the early stage of regeneration. This problem is about to be overcome by increasing the flow rate of air during the regeneration cycle resulting in more oxidizing conditions and hence less tendency for sulfide sulfur (S{sup =}) to oxidize to the intermediate elemental form (S{sup o}) rather than to 4-valent (S{sup +4}).

  3. Hot Coal Gas Desulfurization with manganese-based sorbents. Quarterly report, April--June 1994

    SciTech Connect

    Hepworth, M.T.; Slimane, R.B.

    1994-06-01

    The focus of work being performed on Hot Coal Gas Desulfurization at the Morgantown Energy Technology Center is primarily in the use of zinc titanate sorbents; however, prior studies indicated that an alternate sorbent, manganese dioxide-containing ore in mixture with alumina (75 wt% ore + 25 wt% Al{sub 2}O{sub 3}) appears to be a strong contender to zincbased sorbents. Manganese, for example, has a lower vapor pressure in the elemental state than zinc; hence, it is not as likely to undergo zinc-depletion from the sorbent surface upon loading and regeneration cycles. Also manganese oxide is less readily reduced to the elemental state than iron; hence, the range of reduction potentials for oxygen is somewhat greater than for zinc ferrite. In addition, thermodynamic analysis of the manganese-oxygen-sulfur system shows it to be less amenable to sulfation than zinc ferrite. Also manganese chlorides are much less stable and volatile than zinc chlorides. Potential also exists for utilization of manganese at higher temperatures than zinc ferrite or zinc titanate. This Seventh Quarterly Report documents progress in bench-scale testing of a leading manganese-based sorbent pellets (FORM4-A). This formulation is a high-purity manganese carbonate-based material. This formulation was subjected to 20 consecutive cycles of sulfidation and regeneration at 900{degrees}C in a 2-inch fixed bed reactor. The sulfidation gas was a simulated Tampella U-gas with an increased hydrogen sulfide content of 3% by volume to accelerate the rate of breakthrough, arbitrarily taken as 500 ppmv. Consistent with thermo-gravimetric analysis (TGA) on individual pellets, the fixed bed tests show small improvement in capacity and kinetics with the sulfur-loading capacity being about 22% by weight of the original pellet, which corresponds to approximately 90% bed utilization!

  4. Hot gas desulfurization with sorbents containing oxides of zinc, iron, vanadium and copper. Quarterly technical progress report, July 1992

    SciTech Connect

    Akyurtlu, A.; Akyurtlu, J.F.

    1992-09-01

    The main objective of this research is to evaluate the desulfurization performance of novel sorbents consisting of different combinations of zinc, iron, vanadium and copper oxides; and to develop a sorbent which can reduce H{sub 2}S levels to less than 1 ppmv, which can stabilize zinc, making operations above 650{degrees}C possible, and which can produce economically recoverable amounts of elemental sulfur during regeneration. This objective will be accomplished by evaluating the sorbent performance using fixed-bed and TGA experiments supported by sorbent characterization at various reaction extents. In the seventh quarter, the screening of the promoted sorbents in the packed bed reactor was continued. The results of this work were presented at the 1992 University Coal Research Contractors, Review Conference at Pittsburgh, PA.

  5. Hot Coal Gas Desulfurization with manganese based sorbents. Quarterly report, August 1, 1993--September 30, 1993

    SciTech Connect

    Hepworth, M.T.

    1993-10-01

    The focus of work being performed on Hot Coal Gas Desulfurization at the Morgantown Energy Technology Center is primarily in the use of zinc ferrite and zinc titanate sorbents; however, prior studies at the US Steel Fundamental Research Laboratories in Monroeville, PA, by E. T. Turkdogan indicated that an alternate sorbent, manganese dioxide-containing ore in mixture with alumina (75 wt % ore + 25 wt % Al{sub 2}O{sub 3}) may be a viable alternative to zinc-based sorbents. Manganese, for example, has a lower vapor pressure in the elemental state than zinc hence it is not as likely to undergo depletion from the sorbent surface upon loading and regeneration cycles. Also manganese oxide is less readily reduced to the elemental state than iron hence the range of reduction potentials for oxygen is somewhat greater than for zinc ferrite. In addition, thermodynamic analysis of the manganese-oxygen-sulfur system shows it to be less amenable to sulfation than zinc ferrite. Potential also exists for utilization of manganese at higher temperatures than zinc ferrite or zinc titanate. This report documents progress in pelletizing and testing via thermogravimetric analysis of individual pellet formulations of manganese ore/alumina combinations and also manganese carbonate/alumina with two binders, dextrin and bentonite. Preliminary results indicate that the manganese carbonate material, being of higher purity than the manganese ore, has a higher degree of sulfur capacity and more rapid absorption kinetics. A 2-inch fixed-bed reactor has been fabricated and is now ready for subjecting pellets to cyclic loading and regeneration.

  6. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent. Quarterly technical progress report No. 1, October--December 1986

    SciTech Connect

    Jha, M.C.; Baltich, L.K.

    1987-02-23

    AMAX Research & Development Center (AMAX R&D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such As size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.

  7. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent. Quarterly technical progress report 2, January--March 1987

    SciTech Connect

    Jha, M.C.; Baltich, L.K.; Berggren, M.H.

    1987-05-18

    AMAX Research & Development Center (AMAX R&D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such As size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.

  8. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent. Quarterly technical progress report No. 3, April--June 1987

    SciTech Connect

    Jha, M.C.; Baltich, L.K.; Berggren, M.H.

    1987-08-28

    AMAX Research & Development Center (AMAX R&D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such As size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.

  9. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent. Quarterly technical progress report 8, July--September 1988

    SciTech Connect

    Jha, M.C.; Berggren, M.H.

    1988-11-14

    AMAX Research & Development Center (AMAX R&D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such As size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.

  10. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent. Quarterly technical progress report 7, April--June 1988

    SciTech Connect

    Jha, M.C.; Berggren, M.H.

    1988-08-19

    AMAX Research & Development Center (AMAX R&D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such As size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.

  11. Hot coal gas desulfurization with manganese-based sorbents. Quarterly report, January--March 1994

    SciTech Connect

    Hepworth, M.T.; Slimane, R.B.

    1994-04-01

    The focus of work being performed on Hot Coal Gas Desulfurization at the Morgantown Energy Technology Center is primarily in the use of zinc titanate sorbents; however, prior studies indicated that an alternate sorbent, manganese dioxide-containing ore in mixture with alumina (75 wt% ore + 25 wt% Al{sub 2},O{sub 3}) may be a viable alternative to zinc-based sorbents. Manganese, for example, has a lower vapor pressure in the elemental state than zinc; hence, it is not as likely to undergo zinc-depletion from the sorbent surface upon loading and regeneration cycles. Also manganese oxide is less readily reduced to the elemental state than iron; hence, the range of reduction potentials for oxygen is somewhat greater than for zinc ferrite. In addition, thermodynamic analysis of the manganese-oxygen-sulfur system shows it to be less amenable to sulfation than zinc ferrite. Potential also exists for utilization of manganese at higher temperatures than zinc ferrite or zinc titanate. This Sixth Report documents progress in pellet testing two leading formulations; namely FORM 4-A and FORM 1-A via thermogravimetric analysis (TGA). The former is a high-purity carbonate-based material, and the latter is ore-based. Also fixed bed testing of formulation FORM 1-A is described. Included with this report is an Appendix which describes the formulations and the loading tests as performed via TGA. A 2-inch fixed-bed reactor is being utilized to subject a bed of FORM 4-A pellets to cyclic loading and regeneration. Preliminary results indicate that FORM 1-A can be loaded to approximately 12 per cent of its weight in sulfur prior to breakthrough up through sixteen cycles of loading and regeneration. The sulfur loading level drops from 18.2% for fresh pellets to 11.8% after the sixteenth cycle; however, there is no significant decrease in pellet sulfur-capacity after the ninth cycle. The kinetics during the loading and regeneration cycles are rapid.

  12. Kinetics of Mn-based sorbents for hot coal gas desulfurization. Quarterly progress report, July 15, 1995--September 15, 1995

    SciTech Connect

    Hepworth, M.T.

    1995-09-15

    The Morgantown Energy Technology Center (METC) of the U.S. Department of Energy (DOE) is actively pursuing the development of reliable and cost-effective processes to clean coal gasifier gases for application to integrated gasification combined cycle (IGCC) and molten carbonate fuel cell (MCFC) power plants. A large portion of gas cleanup research has been directed towards hot gas desulfurization using Zn-based sorbents. However, zinc titinate sorbents undergo reduction to the metal at temperatures approaching 700{degrees}C. In addition, sulfate formation during regeneration leads to spalling of reactive 293 surfaces. Due to zinc-based sorbent performance, METC has shown interest in formulating and testing manganese-based sorbents. Westmoreland and Harrison evaluated numerous candidate sulfur sorbents and identified Mn as a good candidate. Later, Turkdogan and Olsson tested manganese-based sorbents which demonstrated superior desulfurization capacity under high temperatures, and reducing conditions. Recently, Ben-Slimane and Hepworth conducted several studies on formulating Mn-sorbents and desulfurizing a simulated fuel gas. Although thermodynamics predicts higher over-pressures with Mn verses Zn, under certain operating conditions Mn-based sorbents may obtain < 20 ppmv. In addition, the manganese-sulfur-oxygen (Mn-S-O) system does not reduce to the metal under even highly reducing gases at high temperatures (550-900{degrees}C). Currently, many proposed IGCC processes include a water quench prior to desulfurization. This is for two reasons; limitations in the process hardware (1000{degrees}C), and excessive Zn-based sorbent loss (about 700{degrees}C). With manganese the water quench is obviated due to sorbent loss, as Mn-based sorbents have been shown to retain reactivity under cycling testing at 900{degrees}C. This reduces system hardware, and increases thermal efficiency while decreasing the equilibrium H{sub 2}S over-pressure obtainable with a manganese sorbent.

  13. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent. Quarterly technical progress report 4, July--September 1987

    SciTech Connect

    Jha, M.C.; Berggren, M.H.

    1987-10-27

    AMAX Research & Development Center (AMAX R&D) has been investigating methods for improving the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hog coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. The reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point in a bench-scale fixed-bed reactor. The durability may be defined as the ability of the sorbent to maintain its reactivity and other important physical characteristics such as size, strength, and specific surface area during 10 cycles of sulfidation and regeneration. Two base case sorbents, spherical pellets and cylindrical extrudes used in related METC sponsored projects, are being used to provide a basis for the comparison of physical characteristics and chemical reactivity.

  14. Kinetics of Mn-based sorbents for hot coal gas desulfurization. Quarterly progress report, March 15, 1995--July 15, 1995

    SciTech Connect

    Hepworth, M.T.

    1995-07-15

    Hot gas desulfurization may be accomplished by using solid sorbents such as oxides of those metals that form stable sulfides. The effectiveness of a desulfurizing agent in treating such gases is related to the predicted equilibrium partial pressure of hydrogen sulfide which will be present in a phase combination of the reduced form of sulfide and oxide phases. The focus of much current work being performed by the Department of Energy on sorbent development is in the use of zinc ferrite, zinc titanate, and Z-Sorb. The latter sorbent is a commercial product consisting of ZnO, a promoter, and a proprietary supporting matrix designed to provide stability and prolong sorbent life. Although these Zn-based sorbents have been the subject of extensive pilot-scale and process development work, all sorbents produced to date still experience structural and reactive degradation over multi-cycle use at relatively moderate temperatures. An effective alternative to zinc-based sorbents could be manganese sorbents which withstand high temperature operation and also maintain structural and reactive integrity over many cycles, as investigations by Ben-Slimane and Hepworth have indicated. Thermodynamic limits may prevent MnO from achieving the low sulfur specifications of the product gas for use in a molten carbonate fuel cell, but under the correct conditions the guideline for IGCC systems can easily be achieved. Furthermore, manganese sorbents could possibly be used in conjunction with a polishing sorbent (such as zinc oxide) possessing more favorable thermodynamic properties to reach levels acceptable for fuel cell applications (< 10 ppmv). Such an arrangement may not require that the zinc sulfide be regenerated since the sulfur concentration of the cleaned gas is low enough that the zinc oxide may be discarded when exhausted.

  15. Hot Coal Gas Desulfurization with manganese-based sorbents. Second [quarterly] technical report, December 1, 1992--March 1, 1993

    SciTech Connect

    Hepworth, M.T.

    1993-03-01

    At present, the focus of work being performed on Hot Coal Gas Desulfurization is primarily in the use of zinc ferrite and zinc titanate sorbents; however studies at the US Steel Fundamental Research Laboratories in Monroeville, PA, by E. T. Turkdogan indicate that an alternate sorbent, manganese dioxide-containing ore in mixture with alumina (75 wt % ore + 25 wt % Al{sub 2}O{sub 3}) may be a preferable alternative to zinc-based sorbents. A significant domestic source of manganese in Minnesota is being explored for an in situ leach process which has potential for producing large tonnages of solutions which may be ideal for precipitation and recovery of pure manganese as a carbonate in a reactive form. In the current program the following studies will be addressed: Preparation of manganese sorbent pellets and characterization tests on pellets for strength and surface area; analysis of the thermodynamics and kinetics of sulfur removal from hot fuel gases by individual sorbent pellets (loading tests) by thermogravimetric testing; regeneration tests via TGA on individual sorbent pellets by oxidation; and bench-scale testing on sorbent beds in a two-inch diameter reactor. The developed information will be of value to METC in its determination of whether or not a manganese-based regenerable sorbent holds real promise for sulfur cleanup of hot fuel gases. This information is necessary prior to pilot-scale testing leading to commercial development is undertaken.

  16. Kinetics of Mn-based sorbents for hot coal gas desulfurization. Quarterly progress report, September 15, 1995--December 15, 1995

    SciTech Connect

    Hepworth, M.T.; Berns, J.

    1995-12-15

    The Morgantown Energy Technology Center (METC) of the U.S. Department of Energy (DOE) is actively pursuing the development of reliable and cost-effective processes to clean coal gasifier gases for application to integrated gasification combined cycle (IGCC) and molten carbonate fuel cell (MCFC) power plants. A large portion of gas cleanup research has been directed towards hot gas desulfurization using Zn-based sorbents. However, zinc titanate sorbents undergo reduction to the metal at temperatures approaching 700{degrees}C and lose reactivity because of volatilization. In addition, sulfate formation during regeneration leads to spalling of reactive surfaces. Because of these problems with zinc-based sorbents, METC has shown interest in formulating and testing manganese-based sorbents. Currently, many proposed IGCC processes include a water quench prior to desulfurization. This quench is required for two reasons; limitations in the process hardware (1000{degrees}C), and excessive Zn-based sorbent loss (about 700{degrees}C). With manganese, the water quench is not necessary to avoid sorbent loss, since Mn-based sorbents have been shown to retain reactivity under cyclic testing at 900{degrees}C. This advantage of manganese over zinc has potential to increase thermal efficiency as the trade-off of increasing the equilibrium H{sub 2}S over-pressure obtainable with a manganese sorbent. In the work which is reported here, lower loading temperatures (as low as 400{degrees}C) are studied. Also formulations containing titania rather then alumina are studied to attempt to improve performance.

  17. LIFAC Sorbent Injection Desulfurization Demonstration Project. Quarterly report No. 6, January--March 1992

    SciTech Connect

    Not Available

    1992-09-01

    The LIFAC technology has similarities to other sorbent injection technologies using humidification, but employs a unique patented vertical reaction chamber located down-stream of the boiler to facilitate and control the sulfur capture and other chemical reactions. This chamber improves the overall reaction efficiency enough to allow the use of pulverized limestone rather than more expensive reagents such as lime which are often used to increase the efficiency of other sorbent injection processes. Sorbent injection is a potentially important alternative to conventional wet lime and limestone scrubbing, and this project is another effort to test alternative sorbent injection approaches. In comparison to wet systems, LIFAC, with recirculation of the sorbent, removes less sulfur dioxide - 75--85% relative to 90% or greater for conventional scrubbers - and requires more reagent material. However, if the demonstration is successful, LIFAC will offer these important advantages over wet scrubbing systems: LIFAC is relatively easy to retrofit to an existing boiler and requires less area than conventional wet FGD systems; LIFAC is less expensive to install than conventional wet FGD processes; LIFAC`s overall costs measured on a dollar-per-ton S0{sub 2} removed basis are less, an important advantage in a regulatory regime with trading of emission allocations. LIFAC produces a dry, readily disposable waste by-product versus a wet product; and LIFAC is relatively simple to operate.

  18. LIFAC Sorbent Injection Desulfurization Demonstration Project. Quarterly report No. 9, October--December 1992

    SciTech Connect

    Not Available

    1992-12-31

    Sorbent injection is a potentially important alternative to conventional wet lime and limestone scrubbing, and this project is another effort to test alternative sorbent injection approaches. In comparison to wet systems, LIFAC, with recirculation of the sorbent, removes less sulfur dioxide - 75--85% relative to 90% or greater for conventional scrubbers -- and requires more reagent material. However, if the demonstration is wet scrubbing systems: LIFAC is relatively easy to retrofit to an existing boiler and requires less area than conventional wet FGD systems. LIFAC is less expensive to install than conventional wet FGD processes. LIFAC`s overall costs measured on a dollar-per-ton SO{sub 2} removed basis are less, an important advantage in a regulatory regime with trading of emission allocations. LIFAC produces a dry, readily disposable waste by-product versus a wet product. LIFAC is relatively simple to operate.

  19. Desulfurization sorbent regeneration

    DOEpatents

    Jalan, V.M.; Frost, D.G.

    1982-07-07

    A spent solid sorbent resulting from the removal of hydrogen sulfide from a fuel gas flow is regenerated with a steam-air mixture. The mixture of steam and air may also include additional nitrogen or carbon dioxide. The gas mixture contacts the spent sorbent containing metal sulfide at a temperature above 500/sup 0/C to regenerate the sulfide to metal oxide or carbonate. Various metal species including the period four transition metals and the lanthanides are suitable sorbents that may be regenerated by this method. In addition, the introduction of carbon dioxide gas permits carbonates such as those of strontium, barium and calcium to be regenerated. The steam permits regeneration of spent sorbent without formation of metal sulfate. Moreover, the regeneration will proceed with low oxygen concentrations and will occur without the increase in temperature to minimize the risk of sintering and densification of the sorbent. This method may be used for high-temperature fuel cells.

  20. LIFAC Sorbent Injection Desulfurization Demonstration Project. Quarterly report number 14, January--March, 1994

    SciTech Connect

    Not Available

    1994-11-01

    The host site for the $22 million, three-phase project is Richmond Power and Light`s Whitewater Valley Unit No. 2 in Richmond, Indiana. The LIFAC technology uses upper-furnace limestone injection with patented humidification of the flue gas to remove 75--85% of the sulfur dioxide (SO{sub 2}) in the flue gas. During this report period (January--March 1994), long-term testing was initiated. The variable frequency drive was placed back in service, but failed again after only a few days of operation. The Unit No. 2 induced draft (ID) fan motor operates at maximum amperage during peak (65 MW) boiler load. LIFAC increases system pressure drop approximately 4.5 inches of water, causing additional loading on the fan motor. A variable frequency drive (VFD) was installed as a major component of the LIFAC system. The VFD interfaces with the ID fan motor by varying motor current as the pressure drop and flue gas volume change, making the fan more efficient and decreasing the stress on the motor. The VFD has failed several times causing boiler Unit No. 2 to trip. Since the VFD has become unreliable, the LIFAC team decided to perform a test on the ID fan motor with the bypass damper fully closed and the VFD disengaged. The objective of long-term testing is to evaluate the performance and operability of the LIFAC process over a long, continuous operation period. There were a total of two test periods during this quarter. Results are presented.

  1. Composition modification of zinc titanate sorbents for hot gas desulfurization. Quarterly report, 1 December 1994--28 February 1995

    SciTech Connect

    Swisher, J.H.; Datta, R.K.

    1995-12-31

    For new coal gasification systems, zinc titanate sorbents are being developed to remove sulfur from the hot product gas prior to its use in combined cycle turbines and high temperature fuel cells. Although most of the properties of these sorbents are very attractive, there are still concerns about durability over many sulfidation-regeneration cycles and zinc losses due to vaporization. Doping the zinc titanate with other metal ions could alleviate both concerns, which are the objectives of this project. A screening study was completed during the second quarter in which Ni, Cr, Cu, Mg, and Al were evaluated as dopants in zinc titanate. Measurements that were made include solubility, crush strength, and sulfidation-regeneration behavior in a thermogravimetric analyzer. A formulation containing Cr showed the most promise. It and other formulations containing Cr will be emphasized during the remainder of the year. Fixed bed experiments will start during the third quarter.

  2. Composition modification of zinc titanate sorbents for hot gas desulfurization. Quarterly technical report, September 1, 1994--November 30, 1994

    SciTech Connect

    Swisher, J.H.; Datta, R.K.

    1995-03-01

    For new coal gasification systems, zinc titanate sorbents are being developed to remove sulfur from the hot product gas prior to its use in combined cycle turbines and high temperature fuel cells. Although most of the properties of these sorbents are very attractive, there are still concerns about durability over many sulfidation-regeneration cycles and zinc losses due to vaporization. Doping the zinc titanate with other metal ions could alleviate both concerns, which are the objectives of this project. During the first quarter of effort, several sorbent formulations were prepared and testing begun. The dopants presently under study are Ni, Cr, Cu, and Al. Crush strength results obtained to date show that Ni and Cu dopants have a large positive effect, while Cr gives a small improvement. Measurements were also made of sulfur capacity and sulfidation rates with a thermogravimetric analyzer. Of the three formulations, only the one containing Cr had a high sulfur capacity. X-ray measurements will be relied upon heavily to obtain an understanding of solubility effects and sulfidation mechanisms. Screening experiments will continue on the doped sorbents mentioned above next quarter, and Mg will be studied also.

  3. Kinetics of Mn-based sorbents for hot coal gas desulfurization. Quarterly progress report, September 15--December 15, 1994. Task 1: Literature review

    SciTech Connect

    Hepworth, M.T.

    1995-01-06

    Manganese ore as well as manganese carbonate, precipitated from aqueous solutions, combined with alumina to form indurated pellets hold promise of being a high-effective, inexpensive, regenerable sorbent for hot fuel gases. Although the thermodynamics for sulfur removal by manganese predicts somewhat higher hydrogen sulfide over-pressures (i.e. poorer degree of desulfurization) than can be accomplished with zinc-based sorbents, zinc tends to be reduced to the metallic state under coal gasification conditions resulting in loss of capacity and reactivity by volatilization of reactive surfaces. This volatilization phenomenon limits the temperatures for which desulfurization can be effectively accomplished to less than 550 C for zinc ferrite and 700 C for zinc titanate; whereas, manganese-based sorbents can be utilized at temperatures well in temperatures exceeding 700 C. Also the regeneration of manganese-based pellets under oxidizing conditions may be superior to that of zinc titanate since they can be loaded from a simulated reducing coal-derived gas and then be regenerated at higher temperatures (up to 1,300 C). The topics that will be addressed by this study include: preparation of an effective manganese-based sorbent; thermodynamics and kinetics of sulfur removal from hot fuel gases by this sorbent; analysis of kinetics and mechanisms by which sulfur is absorbed by the sorbent (i.e., whether by gaseous diffusion, surface-controlled reaction, or pore diffusion); and cyclic sulfidation and regeneration of the sorbent and recovery of the sulfur. 38 refs.

  4. Kinetics of Mn-based sorbents for hot coal gas desulfurization. Quarterly report, September 15 - December 15, 1996

    SciTech Connect

    Hepworth, M.T.

    1996-12-31

    Manganese-based sorbents have been investigated for the removal of hydrogen sulfide (the primary sulfur bearing compound) from hot coal gases prior to its use in combined cycle turbines. Four formulations of Mn-based sorbents were tested in an ambient-pressure fixed-bed reactor to determine steady state H{sub 2}S concentrations, breakthrough times and effectiveness of the sorbent when subjected to cyclic sulfidation and regeneration testing. In a previous report, the sulfidation results were presented. Manganese-based sorbents with molar ratios > 1:1 Mn:Substrate were effective in reducing the H{sub 2}S concentration in simulated coal gases to less than 100 ppmv over five cycles. Actual breakthrough time for formulation C6-2-1100 was as high as 73% of breakthrough time based on wt% Mn in sorbent. In this report, the regeneration results will be presented. Regeneration tests determined that loaded pellets can be fully regenerated in air/steam mixture at 750{degrees}C with minimal sulfate formation. 16 refs., 9 figs., 5 tabs.

  5. Kinetics of Mn-based sorbents for hot coal gas desulfurization. Quarterly report, December 15, 1993--March 15, 1997

    SciTech Connect

    Hepworth, M.T.

    1997-03-03

    Manganese-based sorbents have been investigated for the removal of hydrogen sulfide (the primary sulfur bearing compound) from hot coal gases prior to its use in combined cycle turbines. Four formulations of Mn-based sorbents were tested in an ambient-pressure fixed-bed reactor to determine steady state H{sub 2}S concentrations, breakthrough times and effectiveness of the sorbent when subjected to cyclic sulfidation and regeneration testing. In previous reports, the sulfidation and regeneration results from cyclic testing done at 600{degrees}C were presented. Manganese-based sorbents, with molar ratios > 1:1 Mn:Substrate were effective in reducing the H{sub 2}S concentration in simulated coal gases to less than 100 ppmv over five cycles. Actual breakthrough time for formulation C6-2-1100 was as high as 73% of breakthrough time based on wt% Mn in sorbent. Regeneration tests determined that loaded pellets can be fully regenerated in air/steam mixture at 750{degrees}C with minimal sulfate formation. In this report, the results from cyclic crush strength tests, Sulfur profile tests and cyclic testing at 550{degrees}C and lower flowrate cyclic testing are presented. Crush strength testing done after 5 cycles showed decreases in strength from 12.6% to 57.9%. Cyclic testing at 550{degrees}C showed pre breakthrough concentrations as low as 10 ppmv. Cyclic testing done at 2 L/min and 3 L/min did not show any significant difference in pre breakthrough concentrations or capacity.

  6. Sorbent for use in hot gas desulfurization

    DOEpatents

    Gasper-Galvin, Lee D.; Atimtay, Aysel T.

    1993-01-01

    A multiple metal oxide sorbent supported on a zeolite of substantially silicon oxide is used for the desulfurization of process gas streams, such as from a coal gasifier, at temperatures in the range of about 1200.degree. to about 1600.degree. F. The sorbent is provided by a mixture of copper oxide and manganese oxide and preferably such a mixture with molybdenum oxide. The manganese oxide and the molybdenum are believed to function as promoters for the reaction of hydrogen sulfide with copper oxide. Also, the manganese oxide inhibits the volatilization of the molybdenum oxide at the higher temperatures.

  7. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent

    SciTech Connect

    Jha, M.C.; Baltich, L.K.

    1987-02-23

    AMAX Research Development Center (AMAX R D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such As size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.

  8. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent

    SciTech Connect

    Jha, M.C.; Berggren, M.H.

    1989-05-02

    AMAX Research Development Center (AMAX R D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such As size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.

  9. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent

    SciTech Connect

    Jha, M.C.; Baltich, L.K.; Berggren, M.H.

    1987-05-18

    AMAX Research Development Center (AMAX R D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such As size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.

  10. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent

    SciTech Connect

    Silaban, A.; Harrison, D.P. . Dept. of Chemical Engineering)

    1989-05-02

    AMAX Research Development Center (AMAX R D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such as size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.

  11. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent

    SciTech Connect

    Jha, M.C.; Berggren, M.H.

    1988-11-14

    AMAX Research Development Center (AMAX R D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such As size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.

  12. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent

    SciTech Connect

    Jha, M.C.; Baltich, L.K.; Berggren, M.H.

    1987-08-28

    AMAX Research Development Center (AMAX R D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such As size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.

  13. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent

    SciTech Connect

    Jha, M.C.; Berggren, M.H.

    1988-08-19

    AMAX Research Development Center (AMAX R D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such As size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.

  14. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent

    SciTech Connect

    Jha, M.C.; Berggren, M.H.

    1989-03-06

    AMAX Research Development Center (AMAX R D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such As size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.

  15. Hot gas desulfurization with sorbents containing mixed metal oxides

    SciTech Connect

    Akyurtlu, J.F.; Akyurtlu, A.

    1992-12-31

    Advanced power generation systems such as the integrated gasification combined cycle power generators and the molten carbonate fuel cells have stringent fuel gas desulfurization requirements and process economics dictates that this desulfurization be performed near the temperature of the gasification off-gas. The most advanced hot gas desulfurization technology today is based on the zinc ferrite sorbent which has several shortcomings such as zinc loss by evaporation, and incomplete regeneration due to sulfate formation. The objective of this study is to develop an improved sorbent which can reduce H{sub 2}S levels to 1 ppmv or less, which can stabilize zinc, and produce economically recoverable amounts of elemental sulfur during regeneration. For this purpose, the desulfurization performance.of sorbents prepared by the addition of various amounts of V{sub 2}0{sub 5} to the zinc ferrite sorbent is investigated. Preliminary experiments show that the sorbent containing about 4.8 mass % vanadium shows a superior desulfurization performance compared to zinc ferrite. Addition of vanadium suppresses residual sulfate formation and possibly zinc evaporation. significant quantities of elemental sulfur were observed after the regeneration of vanadium containing sorbents.

  16. Hot gas desulfurization with sorbents containing oxides of zinc, iron, vanadium and copper

    SciTech Connect

    Akyurtlu, A.; Akyurtlu, J.F.

    1992-01-01

    The main objective of this research is to evaluate the desulfurization performance of novel sorbents consisting of different combinations of zinc, iron, vanadium and copper oxides; and to develop a sorbent which can reduce H{sub 2}S levels to less than 1 ppmv, which can stabilize zinc, making operations above 650{degrees}C possible, and which can produce economically recoverable amounts of elemental sulfur during regeneration. This objective will be accomplished by evaluating the sorbent performance using fixed-bed and TGA experiments supported by sorbent characterization at various reaction extents. In the seventh quarter, the screening of the promoted sorbents in the packed bed reactor was continued. The results of this work were presented at the 1992 University Coal Research Contractors, Review Conference at Pittsburgh, PA.

  17. Development of advanced hot-gas desulfurization sorbents. Final report

    SciTech Connect

    Jothimurugesan, K.; Adeyiga, A.A.; Gangwal, S.K.

    1997-10-01

    The objective of this project was to develop hot-gas desulfurization sorbent formulations for relatively lower temperature application, with emphasis on the temperature range from 343--538 C. The candidate sorbents include highly dispersed mixed metal oxides of zinc, iron, copper, cobalt, nickel and molybdenum. The specific objective was to develop suitable sorbents, that would have high and stable surface area and are sufficiently reactive and regenerable at the relatively lower temperatures of interest in this work. Stability of surface area during regeneration was achieved by adding stabilizers. To prevent sulfation, catalyst additives that promote the light-off of the regeneration reaction at lower temperature was considered. Another objective of this study was to develop attrition-resistant advanced hot-gas desulfurization sorbents which show stable and high sulfidation reactivity at 343 to 538 C and regenerability at lower temperatures than leading first generation sorbents.

  18. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent

    SciTech Connect

    Jha, M.C.; Berggren, M.H.

    1987-10-27

    AMAX Research Development Center (AMAX R D) has been investigating methods for improving the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hog coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. The reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point in a bench-scale fixed-bed reactor. The durability may be defined as the ability of the sorbent to maintain its reactivity and other important physical characteristics such as size, strength, and specific surface area during 10 cycles of sulfidation and regeneration. Two base case sorbents, spherical pellets and cylindrical extrudes used in related METC sponsored projects, are being used to provide a basis for the comparison of physical characteristics and chemical reactivity.

  19. Kinetics of hot-gas desulfurization sorbents for transport reactors

    SciTech Connect

    K.C. Kwon

    2000-01-01

    Hot-gas desulfurization for the integrated gasification combined cycle (IGCC) process has been investigated by many researchers to remove effectively hydrogen sulfide with various metal oxide sorbents at elevated temperatures. Various metal oxide sorbents are formulated with metal oxides such as Fe, Co, Zn, and Ti. Initial reaction kinetics of formulated sorbents with hydrogen sulfide is studied in the presence of various amounts of moisture and hydrogen at various reaction temperatures. The objectives of this research are to study initial reaction kinetics for a sorbent-hydrogen sulfide heterogeneous reaction system, to investigate effects of concentrations of hydrogen sulfide, hydrogen, and moisture on dynamic absorption of H{sub 2}S into sorbents, to understand effects of space time of reaction gas mixtures on initial reaction kinetics of the sorbent-hydrogen sulfide system, and to evaluate effects of temperature and sorbent amounts on dynamic absorption of H{sub 2}S into sorbents. Experimental data on initial reaction kinetics of hydrogen sulfide with metal oxide sorbents were obtained with a 0.83-cm{sup 3} differential reactor. The reactivity of MCRH-67 sorbent and AHI-1 was examined. These sorbents were obtained from the Research Triangle Institute (RTI). The sorbents in the form of 70 {micro}m particles are reacted with 1,000--4,000 ppm hydrogen sulfide at 450--600 C. The range of space time of reaction gas mixtures is 0.03--0.09 s. The range of reaction duration is 4--14,400 s.

  20. Core-in-shell sorbent for hot coal gas desulfurization

    DOEpatents

    Wheelock, Thomas D.; Akiti, Jr., Tetteh T.

    2004-02-10

    A core-in-shell sorbent is described herein. The core is reactive to the compounds of interest, and is preferably calcium-based, such as limestone for hot gas desulfurization. The shell is a porous protective layer, preferably inert, which allows the reactive core to remove the desired compounds while maintaining the desired physical characteristics to withstand the conditions of use.

  1. Kinetics of Mn-based sorbents for hot coal gas desulfurization: Quarterly progress report, December 15, 1994--March 15, 1995. Task 2 -- Exploratory experimental studies: Single pellet tests; Rate mechanism analysis

    SciTech Connect

    Hepworth, M.T.

    1995-03-15

    In earlier studies, zinc ferrite and zinc titanate were developed as regenerable sorbents capable of removing hydrogen sulfide from hot fuel gases originating from coal gasification. Manganese ore as well as manganese carbonate, precipitated from aqueous solutions, combined with alumina to form indurated pellets hold promise of being a highly-effective, inexpensive, regenerable sorbent for hot fuel gases. Although the thermodynamics for sulfur removal by manganese predicts somewhat higher hydrogen sulfide over-pressures (i.e. poorer degree of desulfurization) than can be accomplished with zinc-based sorbents, zinc tends to be reduced to the metallic state under coal gasification conditions resulting in loss of capacity and reactivity by volatilization of reactive surfaces. This volatilization phenomenon limits the temperatures for which desulfurization can be effectively accomplished to less than 500 C for zinc ferrite and 700 C for zinc titanate; whereas, manganese-based sorbents can be utilized at temperatures well in temperatures exceeding 700 C. Also the regeneration of manganese-based pellets under oxidizing conditions may be superior to that of zinc titanate since they can be loaded from a simulated reducing coal-derived gas and then be regenerated at higher temperatures (up to 1,300 C). The topics that will be addressed by this study include: preparation of an effective manganese-based sorbent, thermodynamics and kinetics of sulfur removal from hot fuel gases by this sorbent, analysis of kinetics and mechanisms by which sulfur is absorbed by the sorbent (i.e., whether by gaseous diffusion, surface-controlled reaction, ore pore diffusion), and cyclic sulfidation and regeneration of the sorbent and recovery of the sulfur.

  2. Desulfurization sorbent development activities at METC

    SciTech Connect

    Siriwardane, R.V.

    1995-06-01

    Development of a suitable regenerable sorbent is a major barrier issue in the hot gas cleanup program for integrated gasification combined-cycle (IGCC) systems. This has been a challenging problem during the last 20 years, since many of the sorbents developed in the program could not retain their reactivity and physical integrity during repeated cycles of sulfidation and regeneration reactions. A series of promising sorbents (METC 2-10), which were capable of sustaining their reactivity and physical integrity during repeated sulfidation/ regeneration cycles, have been developed at the Morgantown Energy Technology Center (METC). These sorbents were tested both in low-pressure (260 KPa/23 psig) and high-pressure (520 KPa/60.7 psig) fixed-bed reactors at 538{degrees}C (1000{degrees}F) with simulated coal gas. High-pressure testing was continued for 20 cycles with steam regeneration. A major research goal during the last year was to lower the cost of materials utilized during the sorbent preparation. The METC 9 sorbent was prepared by substituting low-cost materials for some of the materials in METC 6 sorbent. The sulfur capacity of the two sorbents were similar during the 20-cycle testing. METC 2 sorbent was exposed to coal gas in the Modular Gas Cleanup Rig and it was later tested in the high-pressure fixed-bed reactor. The reactivity of the METC 2 sorbent was unaffected by the exposure to the coal gas. Development of these sorbents will be continued for both fluid-bed and moving-bed applications.

  3. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent

    SciTech Connect

    Berggren, M.H.; Jha, M.C.

    1989-10-01

    AMAX Research Development Center (AMAX R D) investigated methods for enhancing the reactivity and durability of zinc ferrite desulfurization sorbents. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For this program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such as size, strength, and specific surface area during 10 cycles of sulfidation and oxidation. Two base case sorbents, a spherical pellet and a cylindrical extrude used in related METC-sponsored projects, were used to provide a basis for the aimed enhancement in durability and reactivity. Sorbent performance was judged on the basis of physical properties, single particle kinetic studies based on thermogravimetric (TGA) techniques, and multicycle bench-scale testing of sorbents. A sorbent grading system was utilized to quantify the characteristics of the new sorbents prepared during the program. Significant enhancements in both reactivity and durability were achieved for the spherical pellet shape over the base case formulation. Overall improvements to reactivity and durability were also made to the cylindrical extrude shape. The primary variables which were investigated during the program included iron oxide type, zinc oxide:iron oxide ratio, inorganic binder concentration, organic binder concentration, and induration conditions. The effects of some variables were small or inconclusive. Based on TGA studies and bench-scale tests, induration conditions were found to be very significant.

  4. Enhanced durability of desulfurization sorbents for fluidized-bed applications

    SciTech Connect

    Gupta, R.P.; Gangwal, S.K.

    1991-06-01

    Advanced integrated gasification combined cycle (IGCC) power systems require the development of high-temperature desulfurization sorbents capable of removing hydrogen sulfide from coal gasifier down to very low levels. The objective of this investigation was to identify and demonstrate methods for enhancing the long-term chemical reactivity and mechanical strength of zinc ferrite, a leading regenerable sorbent, for fluidized-bed applications. Fluidized sorbent beds offer significant potential in IGCC systems because of their ability to control the highly exothermic regeneration involved. However, fluidized beds require a durable, attrition-resistant sorbent in the 100--300 {mu}m size range. A bench-scale high-temperature, high- pressure (HTHP) fluidized-bed reactor (7.6-cm I.D.) system capable of operating up to 24 atm and 800{degree}C was designed, built and tested. A total of 175 sulfidation-regeneration cycles were carried out using KRW-type coal gas with various zinc ferrite formulations. A number of sorbent manufacturing techniques including spray drying, impregnation, crushing and screening, and granulation were investigated. While fluidizable sorbents prepared by crushing durable pellets and screening had acceptable sulfur capacity, they underwent excessive attrition during multicycle testing. The sorbent formulations prepared by a proprietary technique were found to have excellent attrition resistance and acceptable chemical reactivity during multicycle testing. However, zinc ferrite was found to be limited to 550{degree}C, beyond which excessive sorbent weakening due to chemical transformations, e.g., iron oxide reduction, was observed.

  5. Kinetics of Mn-based sorbents for hot coal gas desulfurization. Task 2 -- Exploratory experimental studies: Single pellet tests; rate mechanism analysis. Quarterly report, December 15, 1995--March 15, 1996

    SciTech Connect

    Hepworth, M.T.; Berns, J.

    1996-03-15

    Currently, the Morgantown Energy Technology Center, is actively investigating alternative hot fuel gas desulfurization sorbents for application to the Integrated Gasification Combined Cycle (IGCC). A sorbent must be highly active towards sulfur at high temperatures and pressure`s, and under varying degrees of reducing atmospheres. Thus, high conversion of the metal oxide and low hydrogen sulfide exit partial pressures. Also, it must regenerate nearly ideally to maintain activity over numerous cycles. Furthermore, regeneration must yield a sulfur product which is economically recoverable directly or indirectly. This cyclic process requires a holistic approach as any one criteria may eliminate a candidate sorbent from further consideration. Over fifty induration campaigns have been conducted among the fifteens Mn-based sorbent formulations. All indurated sorbents has been tested for crush strength and chemical analysis. Also, fifteen sorbent formulations have been tested in a TGA for at least on e induration condition. Subsequently described are the three main groups of formulations tested. They are the MnCO{sub 3} supported with TiO{sub 2} (with or without bentonite), MnCO{sub 3} supported with Al{sub 2}O{sub 3} (with or without porosity enhancers), and MnO{sub 2} ore supported with alundum (with and without bentonite).

  6. Kinetics of Mn-based sorbents for hot coal gas desulfurization: Task 2, Exploratory experimental studies: Single pellet tests; Rate mechanism analysis. Quarterly report, June 15, 1996--September 15, 1996

    SciTech Connect

    Hepworth, M.T.

    1996-09-11

    Currently, the Morgantown Energy Technology Center, Department of Energy (DOE/METC) is actively investigating alternative hot fuel gas desulfurization sorbents for application to the Integrated Gasification Combined Cycle (IGCC). A sorbent must be highly active towards sulfur at high temperatures and pressures, and under varying degrees of reducing atmospheres. Also, it must regenerate nearly ideally to maintain activity over numerous cycles. Furthermore, regeneration must yield a sulfur product which is economically recoverable directly or indirectly. Several metal oxides have been investigated as regenerable sorbents for the removal of hydrogen sulfide (the primary sulfur bearing compound) from hot fuel gases. MnO was shown to have an intrinsic reaction rate approximately one order of magnitude greater than the rate or reaction with either CaO or ZnO and two orders of magnitude greater than the reaction rate with V{sub 2}0{sub 3}. Manganese also shows desulfurization potential in the temperature range of 600-700{degrees}C where metal oxides currently known to be reactive with H{sub 2}S are unsatisfactorily. In response to stability difficulties of single and binary metal oxide sorbents, increasing effort is being directed towards incorporation of an inert component into sorbent formulation as witnessed by the various Zn-titanates. Primarily, the inert component increases pore structure integrity while stabilizing the active metal oxide against reduction. This report will address testing of Mn-based sorbents in an ambient pressure fixed-bed reactor. Steady-state H{sub 2}S concentrations and breakthrough times will be presented.

  7. The mechanism of coal gas desulfurization by iron oxide sorbents.

    PubMed

    Lin, Yi-Hsing; Chen, Yen-Chiao; Chu, Hsin

    2015-02-01

    This study aims to understand the roles of hydrogen and carbon monoxide during the desulfurization process in a coal gasification system that H2S of the syngas was removed by Fe2O3/SiO2 sorbents. The Fe2O3/SiO2 sorbents were prepared by incipient wetness impregnation. Through the breakthrough experiments and Fourier transform infrared spectroscopy analyses, the overall desulfurization mechanism of the Fe2O3/SiO2 sorbents was proposed in this study. The results show that the major reaction route is that Fe2O3 reacts with H2S to form FeS, and the existence of CO and H2 in the simulated gas significantly affects equilibrium concentrations of H2S and COS. The formation of COS occurs when the feeding gas is blended with CO and H2S, or CO2 and H2S. The pathways in the formation of products from the desulfurization process by the reaction of Fe2O3 with H2S have been successfully established. PMID:25434261

  8. LIFAC Sorbent Injection Desulfurization Demonstration Project

    SciTech Connect

    Not Available

    1992-01-01

    Sorbent injection is a potentially important alternative to conventional wet lime and limestone scrubbing, and this project is another effort to test alternative sorbent injection approaches. In comparison to wet systems, LIFAC, with recirculation of the sorbent, removes less sulfur dioxide - 75--85% relative to 90% or greater for conventional scrubbers -- and requires more reagent material. However, if the demonstration is wet scrubbing systems: LIFAC is relatively easy to retrofit to an existing boiler and requires less area than conventional wet FGD systems. LIFAC is less expensive to install than conventional wet FGD processes. LIFAC's overall costs measured on a dollar-per-ton SO[sub 2] removed basis are less, an important advantage in a regulatory regime with trading of emission allocations. LIFAC produces a dry, readily disposable waste by-product versus a wet product. LIFAC is relatively simple to operate.

  9. Hot coal gas desulfurization with manganese-based sorbents

    SciTech Connect

    Lynch, D.; Hepworth, M.T.

    1993-09-01

    The focus of work being performed on Hot Coal Gas Desulfurization is primarily in the use of zinc ferrite and zinc titanate sorbents; however, prior studies at the US Steel Fundamental Research Laboratories in Monroeville, PA, by E.T. Turkdogan indicated that an alternate sorbent, manganese dioxide-containing ore in mixture with alumina (75 wt % ore + 25 wt % Al{sub 2}/O{sub 3}) may be a viable alternative to zinc-based sorbents. Manganese, for example, has a lower vapor pressure in the elemental state than zinc hence it is not as likely to undergo depletion from the sorbent surface upon loading and regeneration cycles. Also manganese oxide is less readily reduced to the elemental state than iron hence the range of reduction potentials for oxygen is somewhat greater than for zinc ferrite. In addition, thermodynamic analysis of the manganese-oxygen-sulfur system shows it to be less amenable to sulfation than zinc ferrite. Potential also exists for utilization of manganese higher temperatures than zinc ferrite or zinc titanate. This presentation gives the thermodynamic background for consideration of manganese-based sorbents as an alternative to zinc ferrite. To date the work which has been in progress for nine months is limited at this stage to thermogravimetric testing of four formulations of manganese-alumina sorbents to determine the optimum conditions of pelletization and induration to produce reactive pellets.

  10. Hot coal gas desulfurization with manganese-based sorbents

    SciTech Connect

    Hepworth, M.T.

    1993-06-01

    The focus of work being performed on Hot Coal Gas Desulfurization is primarily in the use of zinc ferrite and zinc titanate sorbents; however, prior studies at the U.S. Steel Fundamental Research Laboratories in Monroeville, PA, by E.T. Turkdogan indicated that an alternate sorbent, manganese dioxide-containing ore in mixture with alumina (75 wt% ore + 25 wt% Al{sub 2}O{sub 3}) may be a viable alternative to zinc-based sorbents. Manganese, for example, has a lower vapor pressure in the elemental state than zinc hence it is not as likely to undergo depletion for the sorbent surface upon loading and regeneration cycles. Also manganese oxide is less readily reduced to the elemental state than iron hence the range of reduction potentials for oxygen is somewhat greater than for zinc ferrite. In addition, thermodynamic analysis of the manganese-oxygen-sulfur system shows it to be less amenable to sulfation than zinc ferrite. Potential also exists for utilization of manganese higher temperatures than zinc ferrite or zinc titanate. This presentation give the thermodynamic background for consideration of manganese-based sorbents as an alternative to zinc ferrite. To date the work which has been in progress for nine months is limited at this stage to thermogravimetric testing of four formulations of manganese-alumina sorbents to determine the optimum conditions of pelletization and induration to produce reactive pellets.

  11. Key factor in rice husk Ash/CaO sorbent for high flue gas desulfurization activity.

    PubMed

    Dahlan, Irvan; Lee, Keat Teong; Kamaruddin, Azlina Harun; Mohamed, Abdul Rahman

    2006-10-01

    Siliceous materials such as rice husk ash (RHA) have potential to be utilized as high performance sorbents for the flue gas desulfurization process in small-scale industrial boilers. This study presents findings on identifying the key factorfor high desulfurization activity in sorbents prepared from RHA. Initially, a systematic approach using central composite rotatable design was used to develop a mathematical model that correlates the sorbent preparation variables to the desulfurization activity of the sorbent. The sorbent preparation variables studied are hydration period, x1 (6-16 h), amount of RHA, x2 (5-15 g), amount of CaO, x3 (2-6 g), amount of water, x4 (90-110 mL), and hydration temperature, x5 (150-250 degrees C). The mathematical model developed was subjected to statistical tests and the model is adequate for predicting the SO2 desulfurization activity of the sorbent within the range of the sorbent preparation variables studied. Based on the model, the amount of RHA, amount of CaO, and hydration period used in the preparation step significantly influenced the desulfurization activity of the sorbent. The ratio of RHA and CaO used in the preparation mixture was also a significant factor that influenced the desulfurization activity of the sorbent. A RHA to CaO ratio of 2.5 leads to the formation of specific reactive species in the sorbent that are believed to be the key factor responsible for high desulfurization activity in the sorbent. Other physical properties of the sorbent such as pore size distribution and surface morphology were found to have insignificant influence on the desulfurization activity of the sorbent.

  12. SCALE-UP OF ADVANCED HOT-GAS DESULFURIZATION SORBENTS

    SciTech Connect

    K. JOTHIMURUGESAN; S.K. GANGWAL

    1998-03-01

    The objective of this study was to develop advanced regenerable sorbents for hot gas desulfurization in IGCC systems. The specific objective was to develop durable advanced sorbents that demonstrate a strong resistance to attrition and chemical deactivation, and high sulfidation activity at temperatures as low as 343 C (650 F). Twenty sorbents were synthesized in this work. Details of the preparation technique and the formulations are proprietary, pending a patent application, thus no details regarding the technique are divulged in this report. Sulfidations were conducted with a simulated gas containing (vol %) 10 H{sub 2}, 15 CO, 5 CO{sub 2}, 0.4-1 H{sub 2}S, 15 H{sub 2}O, and balance N{sub 2} in the temperature range of 343-538 C. Regenerations were conducted at temperatures in the range of 400-600 C with air-N{sub 2} mixtures. To prevent sulfation, catalyst additives were investigated that promote regeneration at lower temperatures. Characterization were performed for fresh, sulfided and regenerated sorbents.

  13. Hot coal gas desulfurization with manganese-based sorbents

    SciTech Connect

    Hepworth, M.T.; Ben-Slimane, R.

    1994-12-01

    The focus of work being performed on Hot Coal Gas Desulfurization at the Morgantown Energy Technology Center is primarily in the use of zinc ferrite and zinc titanate sorbents; however, prior studies indicated that an alternate sorbent, manganese dioxide-containing ore in mixture with alumina (75 wt % ore + 25 wt % Al{sub 2}O{sub 3}) may be a viable alternative to zinc-based sorbents. Manganese, for example, has a lower vapor pressure in the elemental state than zinc hence it is not as likely to undergo depletion from the sorbent surface upon loading and regeneration cycles. Also manganese oxide is less readily reduced to the elemental state than iron hence the range of reduction potentials for oxygen is somewhat greater than for zinc ferrite. In addition, thermodynamic analysis of the manganese-oxygen-sulfur system shows it to be less amenable to sulfation than zinc ferrite. Potential also exists for utilization of manganese at higher temperatures than zinc ferrite or zinc titanate. This annual topical report documents progress in pelletizing and testing via thermo-gravimetric analysis of individual pellet formulations of manganese ore/alumina combinations and also manganese carbonate/alumina with two binders, dextrin and bentonite.

  14. Characteristics and reactivity of rapidly hydrated sorbent for semidry flue gas desulfurization.

    PubMed

    Zhang, Jie; You, Changfu; Zhao, Suwei; Chen, Changhe; Qi, Haiying

    2008-03-01

    Semidry flue gas desulfurization with a rapidly hydrated sorbent was studied in a pilot-scale circulating fluidized bed (CFB) experimental facility. The desulfurization efficiency was measured for various operating parameters, including the sorbent recirculation rate and the water spray method. The experimental results show that the desulfurization efficiencies of the rapidly hydrated sorbent were 1.5-3.0 times higher than a commonly used industrial sorbent for calcium to sulfur molar ratios from 1.2 to 3.0, mainly due to the higher specific surface area and pore volume. The Ca(OH)2 content in the cyclone separator ash was about 2.9% for the rapidly hydrated sorbent and was about 0.1% for the commonly used industrial sorbent, due to the different adhesion between the fine Ca(OH)2 particles and the fly ash particles, and the low cyclone separation efficiency for the fine Ca(OH)2 particles that fell off the sorbent particles. Therefore the actual recirculation rates of the active sorbent with Ca(OH)2 particles were higher for the rapidly hydrated sorbent, which also contributed to the higher desulfurization efficiency. The high fly ash content in the rapidly hydrated sorbent resulted in good operating stability. The desulfurization efficiency with upstream water spray was 10-15% higher than that with downstream water spray.

  15. Hot coal-gas desulfurization with manganese-based sorbents

    SciTech Connect

    Berns, J.; Hepworth, M.T.; Slimane, R.B.; Gasper-Galvin, L.D.; Fisher, E.P.; Venkataraman, V.K.

    1996-08-01

    Manganese based hot-gas-desulfurization sorbents are under investigation for use in Integrated Gasification Combined Cycle advanced electric-power-generation systems. The objective of this project is to develop a regenerable Mn-based pellet formulation that can achieve low sulfur partial pressures, has a high capacity for sulfur and sufficient strength for potential use in fluidized beds, and can be regenerated for many cycles. Fifteen different formulations of manganese sesquioxide, each with either titania or alumina, were prepared and characterized at the University of Minnesota. Each formulation was indurated under conditions sufficient to achieve 1 lb/pellet/mm of diameter crush strength. Sulfidation screening was performed in a thermogravimetric analyzer at 500 to 900 C. A sorbent containing MnCO{sub 3} and TiO{sub 2}, which showed superior crush strength and reactivity, was selected for multi-cycle fixed-bed testing at the Morgantown Energy Technology Center. Four cycles of sulfidation showed that the sorbent had excellent efficiency and capacity for sulfur removal. Good regenerability was achieved with air-steam at 871 C.

  16. Characteristics and reactivity of rapidly hydrated sorbent for semidry flue gas desulfurization

    SciTech Connect

    Jie Zhang; Changfu You; Suwei Zhao; Changhe Chen; Haiying Qi

    2008-03-01

    The semidry flue gas desulfurization (FGD) process has many advantages over the wet FGD process for moving sulfur dioxide emissions from pulverized coal-fired power plants. Semidry FGD with a rapidly hydrated sorbent was studied in a pilot-scale circulating fluidized bed (CFB) experimental facility. The sorbent was made from lumps of lime and coal fly ash. The desulfurization efficiency was measured for various operating parameters, including the sorbent recirculation rate and the water spray method. The experimental results show that the desulfurization efficiencies of the rapidly hydrated sorbent were 1.5-3.0 times higher than a commonly used industrial sorbent for calcium to sulfur molar ratios from 1.2 to 3.0, mainly due to the higher specific surface area and pore volume. The Ca(OH){sub 2} content in the cyclone separator ash was about 2.9% for the rapidly hydrated sorbent and was about 0.1% for the commonly used industrial sorbent, due to the different adhesion between the fine Ca(OH){sub 2} particles and the fly ash particles, and the low cyclone separation efficiency for the fine Ca(OH){sub 2} particles that fell off the sorbent particles. Therefore the actual recirculation rates of the active sorbent with Ca(OH){sub 2} particles were higher for the rapidly hydrated sorbent, which also contributed to the higher desulfurization efficiency. The high fly ash content in the rapidly hydrated sorbent resulted in good operating stability. The desulfurization efficiency with upstream water spray was 10-15% higher than that with downstream water spray. 20 refs., 7 figs., 1 tab.

  17. Adhesive carrier particles for rapidly hydrated sorbent for moderate-temperature dry flue gas desulfurization.

    PubMed

    Li, Yuan; You, Changfu; Song, Chenxing

    2010-06-15

    A rapidly hydrated sorbent for moderate-temperature dry flue gas desulfurization was prepared by rapidly hydrating adhesive carrier particles and lime. The circulation ash from a circulating fluidized bed boiler and chain boiler ash, both of which have rough surfaces with large specific surface areas and specific pore volumes, can improve the adhesion, abrasion resistance, and desulfurization characteristics of rapidly hydrated sorbent when used as the adhesive carrier particles. The adhesion ability of sorbent made from circulation ash is 67.4% higher than that of the existing rapidly hydrated sorbent made from fly ash, the abrasion ratio is 76.2% lower, and desulfurization ability is 14.1% higher. For sorbent made from chain boiler ash, the adhesion ability is increased by 74.7%, the desulfurization ability is increased by 30.3%, and abrasion ratio is decreased by 52.4%. The abrasion ratios of the sorbent made from circulation ash having various average diameters were all about 9%, and their desulfurization abilities were similar (approximately 150 mg/g). PMID:20481549

  18. Hot coal gas desulfurization with manganese-based sorbents. Annual report, September 1992--September 1993

    SciTech Connect

    Hepworth, M.T.

    1993-12-01

    The focus of work being performed on Hot Coal Gas Desulfurization at the Morgantown Energy Technology Center is primarily in the use of zinc ferrite and zinc titanate sorbents; however, prior studies at the US Steel Fundamental Research Laboratories in Monroeville, PA, by E. T. Turkdogan indicated that an alternate sorbent, manganese dioxide-containing ore in mixture with alumina (75 wt % ore + 25 wt % Al{sub 2}O{sub 3}) may be a viable alternative to zinc-based sorbents. Manganese, for example, has a lower vapor pressure in the elemental state than zinc hence it is not as likely to undergo depletion from the sorbent surface upon loading and regeneration cycles. Also manganese oxide is less readily reduced to the elemental state than iron hence the range of reduction potentials for oxygen is somewhat greater than for zinc ferrite. In addition, thermodynamic analysis of the manganese-oxygen-sulfur system shows it to be less amenable to sulfation than zinc ferrite. Potential also exists for utilization of manganese at higher temperatures than zinc ferrite or zinc titanate. This Annual Topical Report documents progress in pelletizing and testing via thermo-gravimetric analysis of individual pellet formulations of manganese ore/ alumina combinations and also manganese carbonate/alumina with two binders, dextrin and bentonite. It includes the prior Quarterly Technical Reports which indicate that the manganese carbonate material, being of higher purity than the manganese ore, has a higher degree of sulfur capacity and more rapid absorption kinetics. A 2-inch fixed-bed reactor has been fabricated and is now ready for subjecting pellets to cyclic loading and regeneration.

  19. Pore structure and reactivity changes in hot coal gas desulfurization sorbents

    SciTech Connect

    Sotirchos, S.V.

    1991-05-01

    The primary objective of the project was the investigation of the pore structure and reactivity changes occurring in metal/metal oxide sorbents used for desulfurization of hot coal gas during sulfidation and regeneration, with particular emphasis placed on the effects of these changes on the sorptive capacity and efficiency of the sorbents. Commercially available zinc oxide sorbents were used as model solids in our experimental investigation of the sulfidation and regeneration processes.

  20. Sulfidation of a Novel Iron Sorbent Supported on Lignite Chars during Hot Coal Gas Desulfurization

    NASA Astrophysics Data System (ADS)

    Yin, Fengkui; Yu, Jianglong; Gupta, Sushil; Wang, Shaoyan; Wang, Dongmei; Yang, Li; Tahmasebi, Arash

    The sulfidation behavior of novel iron oxide sorbents supported using activated-chars during desulfurization of hot coal gases has been studied. The sulfidation of the char-supported sorbents was investigated using a fixed-bed quartz reactor in the temperature range of 673K to 873K. The product gases were analyzed using a GC equipped with a TCD and a FPD detector. The sorbent samples before and after sulfidation were examined using SEM and XRD.

  1. Pore structure and reactivity changes in hot coal gas desulfurization sorbents

    SciTech Connect

    Sotirchos, S.V.

    1989-01-01

    A research program is proposed for the investigation of the dependence of the sorptive capacity of metal/metal oxide desulfurization sorbents on their pore size distribution and their intraparticle diffusivity. Integrated reaction/adsorption systems, chromatographic and gravimetric, will be used for successive reactivity, adsorption, and well as diffusivity, measurements. Single particle models that have been developed by our research group for gas-solid reactions with solid product will be used as basis for experimental data analysis and development of a general mathematical model for fixed-bed desulfurization and sorbent regeneration.

  2. Characterization and optimization of sorbents utilized for emission control during coal gasification. 1997 Fourth quarter research report, October 1, 1997--December 31, 1997

    SciTech Connect

    Huque, Z.; Mei, D.; Zhou, J.

    1997-12-31

    Advanced integrated gasification combined cycle and pressurized fluidized bed combustion power system requires both hot gas desulfurization and particulate filtration to improve system thermal efficiency and overall performance. Few metal oxides were evaluated to be the sorbent candidate for hot gas desulfurization process. The use of waste iron oxide as a disposable metal oxide sorbent will alleviate the constraints imposed on iron oxides including the degradation of sulfur capacity and its physical attrition required for a regenerable sorbent. The very low cost of waste iron oxides and the elimination of the investment associated with sorbent regeneration make it attractive to replace currently developed sorbent candidates. However, the use of waste iron oxides indicates a significant increase of dust loading for particulate filtration. The slower the reaction rate the iron oxide and coal ash mixture is, the longer residence time and higher iron oxide to coal ratio are required. One of the key issue of the use of waste iron oxides as a disposable sorbent material relies on the capability of particulate filtration efficiency. The current back pulse cleaning of the dust cake had been evaluated; and the preliminary test results indicated that the simultaneous operation of hot gas desulfurization and particulate filtration is feasible. A parametric testing will be performed on hot gas desulfurization and particulate independently first. The independent test results will help optimize the test design and evaluation of the integration of hot gas desulfurization testing and particulate filtration testing to be completed in the first two quarters 1998.

  3. Experimental study on the reuse of spent rapidly hydrated sorbent for circulating fluidized bed flue gas desulfurization.

    PubMed

    Li, Yuan; Zheng, Kai; You, Changfu

    2011-11-01

    Rapidly hydrated sorbent, prepared by rapidly hydrating adhesive carrier particles and lime, is a highly effective sorbent for moderate temperature circulating fluidized bed flue gas desulfurization (CFB-FGD) process. The residence time of fine calcium-containing particles in CFB reactors increases by adhering on the surface of larger adhesive carrier particles, which contributes to higher sorbent calcium conversion ratio. The circulation ash of CFB boilers (α-adhesive carrier particles) and the spent sorbent (β and γ-adhesive carrier particles) were used as adhesive carrier particles for producing the rapidly hydrated sorbent. Particle physical characteristic analysis, abrasion characteristics in fluidized bed and desulfurization characteristics in TGA and CFB-FGD systems were investigated for various types of rapidly hydrated sorbent (α, β, and γ-sorbent). The adhesion ability of γ-sorbent was 50.1% higher than that of α-sorbent. The abrasion ratio of β and γ-sorbent was 16.7% lower than that of α-sorbent. The desulfurization abilities of the three sorbent in TGA were almost same. The desulfurization efficiency in the CFB-FGD system was up to 95% at the bed temperature of 750 °C for the β-sorbent. PMID:21928832

  4. Highly stable and regenerable Mn-based/SBA-15 sorbents for desulfurization of hot coal gas.

    PubMed

    Zhang, F M; Liu, B S; Zhang, Y; Guo, Y H; Wan, Z Y; Subhan, Fazle

    2012-09-30

    A series of mesoporous xCuyMn/SBA-15 sorbents with different Cu/Mn atomic ratios were prepared by wet impregnation method and their desulfurization performance in hot coal gas was investigated in a fixed-bed quartz reactor in the range of 700-850°C. The successive nine desulfurization-regeneration cycles at 800°C revealed that 1Cu9Mn/SBA-15 presented high performance with durable regeneration ability due to the high dispersion of Mn(2)O(3) particles incorporated with a certain amount of copper oxides. The breakthrough sulfur capacity of 1Cu9Mn/SBA-15 observed 800°C is 13.8 g S/100g sorbents, which is remarkably higher than these of 40 wt%LaFeO(3)/SBA-15 (4.8 g S/100g sorbents) and 50 wt%LaFe(2)O(x)/MCM-41 (5.58 g S/100g sorbents) used only at 500-550°C. This suggested that the loading of Mn(2)O(3) active species with high thermal stability to SBA-15 support significantly increased sulfur capacity at relatively higher sulfidation temperature. The fresh and used xCuyMn/SBA-15 sorbents were characterized by means of BET, XRD, XPS, XAES, TG/DSC and HRTEM techniques, confirmed that the structure of the sorbents remained intact before and after hot coal gas desulfurization.

  5. Highly stable and regenerable Mn-based/SBA-15 sorbents for desulfurization of hot coal gas.

    PubMed

    Zhang, F M; Liu, B S; Zhang, Y; Guo, Y H; Wan, Z Y; Subhan, Fazle

    2012-09-30

    A series of mesoporous xCuyMn/SBA-15 sorbents with different Cu/Mn atomic ratios were prepared by wet impregnation method and their desulfurization performance in hot coal gas was investigated in a fixed-bed quartz reactor in the range of 700-850°C. The successive nine desulfurization-regeneration cycles at 800°C revealed that 1Cu9Mn/SBA-15 presented high performance with durable regeneration ability due to the high dispersion of Mn(2)O(3) particles incorporated with a certain amount of copper oxides. The breakthrough sulfur capacity of 1Cu9Mn/SBA-15 observed 800°C is 13.8 g S/100g sorbents, which is remarkably higher than these of 40 wt%LaFeO(3)/SBA-15 (4.8 g S/100g sorbents) and 50 wt%LaFe(2)O(x)/MCM-41 (5.58 g S/100g sorbents) used only at 500-550°C. This suggested that the loading of Mn(2)O(3) active species with high thermal stability to SBA-15 support significantly increased sulfur capacity at relatively higher sulfidation temperature. The fresh and used xCuyMn/SBA-15 sorbents were characterized by means of BET, XRD, XPS, XAES, TG/DSC and HRTEM techniques, confirmed that the structure of the sorbents remained intact before and after hot coal gas desulfurization. PMID:22835768

  6. Optimizing the specific surface area of fly ash-based sorbents for flue gas desulfurization.

    PubMed

    Lee, K T; Bhatia, S; Mohamed, A R; Chu, K H

    2006-01-01

    High performance sorbents for flue gas desulfurization can be synthesized by hydration of coal fly ash, calcium sulfate, and calcium oxide. In general, higher desulfurization activity correlates with higher sorbent surface area. Consequently, a major aim in sorbent synthesis is to maximize the sorbent surface area by optimizing the hydration conditions. This work presents an integrated modeling and optimization approach to sorbent synthesis based on statistical experimental design and two artificial intelligence techniques: neural network and genetic algorithm. In the first step of the approach, the main and interactive effects of three hydration variables on sorbent surface area were evaluated using a full factorial design. The hydration variables of interest to this study were hydration time, amount of coal fly ash, and amount of calcium sulfate and the levels investigated were 4-32 h, 5-15 g, and 0-12 g, respectively. In the second step, a neural network was used to model the relationship between the three hydration variables and the sorbent surface area. A genetic algorithm was used in the last step to optimize the input space of the resulting neural network model. According to this integrated modeling and optimization approach, an optimum sorbent surface area of 62.2m(2)g(-1) could be obtained by mixing 13.1g of coal fly ash and 5.5 g of calcium sulfate in a hydration process containing 100ml of water and 5 g of calcium oxide for a fixed hydration time of 10 h.

  7. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent. Volume 2, Single particle kinetic studies of sulfidation and regeneration reactions of candidate zinc ferrite sorbents

    SciTech Connect

    Silaban, A.; Harrison, D.P.

    1989-05-02

    AMAX Research & Development Center (AMAX R&D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such as size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.

  8. Desulfurization of liquid fuels by adsorption on carbon-based sorbents and ultrasound-assisted sorbent regeneration.

    PubMed

    Wang, Yuhe; Yang, Ralph T

    2007-03-27

    Several carbon-based adsorbents, CuCl/AC, PdCl2/AC, and Pd/AC (where AC denotes activated carbon), were studied for desulfurization of a model jet fuel by selective adsorption of thiophenic molecules. Comparisons with gamma-Al2O3 support and desulfurization of a commercial jet fuel were also studied. The results showed that the selective sulfur adsorption capacity of PdCl2 was higher than that of CuCl and Pd(0), in agreement with molecular orbital results. It was also found that the activated carbon is the best support for pi-complexation sorbents to remove sulfur-containing compounds, i.e., benzothiophene and methylbenzothiophene. Among all the adsorbents studied, PdCl2/AC had the highest capacity for desulfurization. A significant synergistic effect was observed between the carbon substrate and the supported pi-complexation sorbent, and this effect was explained by a geometric effect. The saturated sorbent was regenerated by desorption assisted by ultrasound with a solvent of 30 wt % benzene and 70 wt % n-octane. The results showed that the amount of sulfur desorbed was higher with ultrasound, 65 wt % desorption vs 45 wt % without ultrasound in a static system at 50 degrees C.

  9. Method for reducing sulfate formation during regeneration of hot-gas desulfurization sorbents

    DOEpatents

    Bissett, Larry A.; Strickland, Larry D.; Rockey, John M.

    1994-01-01

    The regeneration of sulfur sorbents having sulfate forming tendencies and used for desulfurizing hot product gas streams such as provided by coal gasification is provided by employing a two-stage regeneration method. Air containing a sub-stoichiometric quantity of oxygen is used in the first stage for substantially fully regenerating the sorbent without sulfate formation and then regeneration of the resulting partially regenerated sorbent is completed in the second stage with air containing a quantity of oxygen slightly greater than the stoichiometric amount adequate to essentially fully regenerate the sorbent. Sulfate formation occurs in only the second stage with the extent of sulfate formation being limited only to the portion of the sulfur species contained by the sorbent after substantially all of the sulfur species have been removed therefrom in the first stage.

  10. Iron blast furnace slag/hydrated lime sorbents for flue gas desulfurization.

    PubMed

    Liu, Chiung-Fang; Shih, Shin-Min

    2004-08-15

    Sorbents prepared from iron blast furnace slag (BFS) and hydrated lime (HL) through the hydration process have been studied with the aim to evaluate their reactivities toward SO2 under the conditions prevailing in dry or semidry flue gas desulfurization processes. The BFS/HL sorbents, having large surface areas and pore volumes due to the formation of products of hydration, were highly reactive toward SO2, as compared with hydrated lime alone (0.24 in Ca utilization). The sorbent reactivity increased as the slurrying temperature and time increased and as the particle size of BFS decreased; the effects of the liquid/solid ratio and the sorbent drying conditions were negligible. The structural properties and the reactivity of sorbent were markedly affected by the BFS/HL ratio; the sorbent with 30/70 ratio had the highest 1 h utilization of Ca, 0.70, and SO2 capture, 0.45 g SO2/g sorbent. The reactivity of a sorbent was related to its initial specific surface area (Sg0) and molar content of Ca (M(-1)); the 1 h utilization of Ca increased almost linearly with increasing Sg0/M. The results of this study are useful to the preparation of BFS/HL sorbents with high reactivity for use in the dry and semidry processes to remove SO2 from the flue gas.

  11. Iron blast furnace slag/hydrated lime sorbents for flue gas desulfurization.

    PubMed

    Liu, Chiung-Fang; Shih, Shin-Min

    2004-08-15

    Sorbents prepared from iron blast furnace slag (BFS) and hydrated lime (HL) through the hydration process have been studied with the aim to evaluate their reactivities toward SO2 under the conditions prevailing in dry or semidry flue gas desulfurization processes. The BFS/HL sorbents, having large surface areas and pore volumes due to the formation of products of hydration, were highly reactive toward SO2, as compared with hydrated lime alone (0.24 in Ca utilization). The sorbent reactivity increased as the slurrying temperature and time increased and as the particle size of BFS decreased; the effects of the liquid/solid ratio and the sorbent drying conditions were negligible. The structural properties and the reactivity of sorbent were markedly affected by the BFS/HL ratio; the sorbent with 30/70 ratio had the highest 1 h utilization of Ca, 0.70, and SO2 capture, 0.45 g SO2/g sorbent. The reactivity of a sorbent was related to its initial specific surface area (Sg0) and molar content of Ca (M(-1)); the 1 h utilization of Ca increased almost linearly with increasing Sg0/M. The results of this study are useful to the preparation of BFS/HL sorbents with high reactivity for use in the dry and semidry processes to remove SO2 from the flue gas. PMID:15382877

  12. Enhanced durability and reactivity for zinc ferrite desulfurization sorbent. Volume 1, Bench-scale testing and analysis

    SciTech Connect

    Jha, M.C.; Berggren, M.H.

    1989-05-02

    AMAX Research & Development Center (AMAX R&D) has been investigating methods for enhancing the reactivity and durability of the zinc ferrite desulfurization sorbent. Zinc ferrite sorbents are intended for use in desulfurization of hot coal gas in integrated gasification combined cycle (IGCC) or molten carbonate fuel cell (MCFC) applications. For the present program, the reactivity of the sorbent may be defined as its sulfur sorption capacity at the breakthrough point and at saturation in a bench-scale, fixed-bed reactor. Durability may be defined as the ability of the sorbent to maintain important physical characteristics such As size, strength, and specific surface area during 10 cycles of sulfidation and oxidation.

  13. An investigation into Cu-Mn based sorbent for hot gas desulfurization

    SciTech Connect

    Wan Chen; Sha Xingzhong; Shen Wenqin; Xiong Lihong

    1998-12-31

    In the integrated gasification combined cycle for generation of electricity from coal, the efficient removal of sulfur is essential for improvement in thermal efficiency and process simplification. A family of copper manganese oxide sorbents has been studied. They show better strength and higher sulfur capacity than zinc based sorbents. The integrated gasification combined cycle (IGCC) is one of the most attractive technologies for advanced electricity generation. The coal gas cleanup process is necessary not only for the protection of gas turbine hardware, but also in compliance with the environmental requirements. In order to improve the efficiency of the overall cycle and simplify the process, the coal gas is purified at high temperature. For removal of hydrogen sulfide, the focus of much current work on hot coal gas desulfurization is primarily on the usage of zinc ferrite and zinc titanate sorbents. Zinc titanate is a promising sorbent and displays better strength than zinc ferrite, but its sulfur capacity is low. Therefore novel sorbents are still being searched for which can show improved properties. A family of copper manganese oxide sorbents has been studied and then their desulfurization properties are introduced here.

  14. Microbial stabilization of sulfur-laden sorbents. [Quarterly] technical report, March 1, 1993--May 31, 1993

    SciTech Connect

    Miller, K.W.

    1993-09-01

    Clean coal technologies that involve limestone for in situ sulfur capture generate lime/limestone products laden with sulfur at various oxidation states. If sulfur is completely stabilized as sulfate, the spent sorbent is ready for commercial utilization as gypsum. However, the presence of reduced sulfur species requires additional processing. Thermal oxidation of reduced sulfur frequently results in undesirable release of SO{sub 2}. Microbial oxidation might provide an inexpensive and effective alternative. Sorbents laden with reduced forms of sulfur such as sulfide or sulfite can serve as growth substrates for sulfur-oxidizing bacteria, which convert all sulfur to sulfate. The goals of this project are the following: (1) to optimize conditions for sulfate generation from sulfide, thiosulfate, and sulfite; (2) to test and optimize the effectiveness of microbial processing on spent sorbents from flue gas desulfurization, coal gasification, and fluidized bed combustion; (3) to search for hyperalkalinophilic thiobacilli, which would be effective up to pH 11. This quarter, temperature, nitrogen, and phosphate requirements for sulfate generation on thiosulfate were optimized with respect to two named strains and two promising isolates. Spent sorbents from three different power plants were tested for sulfite and thiosulfate contents, in preparation for bioprocessing.

  15. Enhanced durability of high-temperature desulfurization sorbents for moving-bed applications

    SciTech Connect

    Ayala, R.E.

    1991-08-01

    The objective of this contract was to identify and test fabrication methods and sorbent chemical compositions that enhance the long-term chemical reactivity and mechanical strength of zinc ferrite and other novel sorbents for moving-bed, high-temperature desulfurization of coal-derived gases. Desired properties to be enhanced for moving-bed sorbent materials are: (1) high chemical reactivity (sulfur absorption rate and total sulfur capacity), (2) high mechanical strength (pellet crush strength and attrition resistance), and (3) suitable pellet morphology (e.g., pellet size, shape, surface area, and average specific pore volume). In addition, it is desired to maintain the sorbent properties over extended cyclic use in moving- bed systems.

  16. Hot coal gas desulfurization with manganese-based sorbents. Final report, September 1992--December 1994

    SciTech Connect

    Hepworth, M.T.; Slimane, R.B.

    1994-11-01

    The focus of much current work being performed by the Morgantown Energy Technology Center (METC) of the Department of Energy on hot coal-derived fuel gas desulfurization is in the use of zinc-based sorbents. METC has shown interest in formulating and testing manganese-based pellets as alternative effective sulfur sorbents in the 700 to 1200{degree}C temperature range. To substantiate the potential superiority of Mn-based pellets, a systematic approach toward the evaluation of the desulfurizing power of single-metal sorbents is developed based on thermodynamic considerations. This novel procedure considered several metal-based sorbents and singled out manganese oxide as a prime candidate sorbent capable of being utilized under a wide temperature range, irrespective of the reducing power (determined by CO{sub 2}/CO ratio) of the fuel gas. Then, the thermodynamic feasibility of using Mn-based pellets for the removal of H{sub 2}S from hot-coal derived fuel gases, and the subsequent oxidative regeneration of loaded (sulfided) pellets was established. It was concluded that MnO is the stable form of manganese for virtually all commercially available coal-derived fuel gases. In addition, the objective of reducing the H{sub 2}S concentration below 150 ppMv to satisfy the integrated gasification combined cycle system requirement was shown to be thermodynamically feasible. A novel process is developed for the manufacture of Mn-based spherical pellets which have the desired physical and chemical characteristics required.

  17. Process for the manufacture of an attrition resistant sorbent used for gas desulfurization

    DOEpatents

    Venkataramani, Venkat S.; Ayala, Raul E.

    2003-09-16

    This process produces a sorbent for use in desulfurization of coal gas. A zinc titanate compound and a metal oxide are mixed by milling the compounds in an aqueous medium, the resulting mixture is dried and then calcined, crushed, sleved and formed into pellets for use in a moving-bed reactor. Metal oxides suitable for use as an additive in this process include: magnesium oxide, magnesium oxide plus molybdenum oxide, calcium oxide, yttrium oxide, hafnium oxide, zirconium oxide, cupric oxide, and tin oxide. The resulting sorbent has a percentage of the original zinc or titanium ions substituted for the oxide metal of the chosen additive.

  18. Enhanced durability of desulfurization sorbents for fluidized-bed applications

    SciTech Connect

    Gupta, R.P.; Gangwal, S.K.

    1992-11-01

    To extend the operating temperature range and further improve the durability of fluidizable sorbents, zinc titanate, another leading regenerable sorbent, was selected for development in the later part of this project. A number of zinc titanate formulations were prepared in the 50 to 300 [mu]m range using granulation and spray drying methods. Important sorbent preparation variables investigated included zinc to titanium ratio, binder type, binder amount, and various chemical additives such as cobalt and molybdenum. A number of sorbents selected on the basis of screening tests were subjected to bench-scale testing for 10 cycles at high temperature, high pressure (HTHP) conditions using the reactor system designed and constructed during the base program. This reactor system is capable of operation either as a 2.0 in. or 3.0 in. I.D. bubbling bed and is rated up to 20 atm operation at 871[degrees]C. Bench-scale testing variables included sorbent type, temperature (550 to 750[degrees]C), gas type (KRW or Texaco gasifier gas), steam content of coal gas, and fluidizing gas velocity (6 to 15 cm/s). The sorbents prepared by spray drying showed poor performance in terms of attrition resistance and chemical reactivity. On the other hand, the granulation method proved to be very successful. For example, a highly attrition-resistant zinc titanate formulation, ZT-4, prepared by granulation exhibited virtually no zinc loss and demonstrated a constant high reactivity and sulfur capacity over 10 cycles, i.e., approximately a 60 percent capacity utilization, with Texaco gas at 750[degrees]C, 15 cm/s fluidizing velocity and 15 atm pressure. The commercial potential of the granulation method for zinc titanate manufacture was demonstrated by preparing two 80 lb batches of sorbent with zinc to titanium mol ratios of 0.8 and 1.5.

  19. Enhanced durability of desulfurization sorbents for fluidized-bed applications

    SciTech Connect

    Gupta, R.P.; Gangwal, S.K.

    1992-11-01

    To extend the operating temperature range and further improve the durability of fluidizable sorbents, zinc titanate, another leading regenerable sorbent, was selected for development in the later part of this project. A number of zinc titanate formulations were prepared in the 50 to 300 {mu}m range using granulation and spray drying methods. Important sorbent preparation variables investigated included zinc to titanium ratio, binder type, binder amount, and various chemical additives such as cobalt and molybdenum. A number of sorbents selected on the basis of screening tests were subjected to bench-scale testing for 10 cycles at high temperature, high pressure (HTHP) conditions using the reactor system designed and constructed during the base program. This reactor system is capable of operation either as a 2.0 in. or 3.0 in. I.D. bubbling bed and is rated up to 20 atm operation at 871{degrees}C. Bench-scale testing variables included sorbent type, temperature (550 to 750{degrees}C), gas type (KRW or Texaco gasifier gas), steam content of coal gas, and fluidizing gas velocity (6 to 15 cm/s). The sorbents prepared by spray drying showed poor performance in terms of attrition resistance and chemical reactivity. On the other hand, the granulation method proved to be very successful. For example, a highly attrition-resistant zinc titanate formulation, ZT-4, prepared by granulation exhibited virtually no zinc loss and demonstrated a constant high reactivity and sulfur capacity over 10 cycles, i.e., approximately a 60 percent capacity utilization, with Texaco gas at 750{degrees}C, 15 cm/s fluidizing velocity and 15 atm pressure. The commercial potential of the granulation method for zinc titanate manufacture was demonstrated by preparing two 80 lb batches of sorbent with zinc to titanium mol ratios of 0.8 and 1.5.

  20. Hot coal gas desulfurization with manganese-based sorbents

    SciTech Connect

    Hepworth, M.T.; Ben-Slimane, R.

    1995-11-01

    The primary major deposit of manganese in the US which can be readily mined by an in situ process is located in the Emily district of Minnesota. The US Bureau of Mines Research Centers at both the Twin Cities and Salt Lake City have developed a process for extracting and refining manganese in the form of a high-purity carbonate product. This product has been formulated into pellets by a multi-step process of drying, calcination, and induration to produce relatively high-strength formulations which are capable of being used for hot fuel gas desulfurization. These pellets, which have been developed at the University of Minnesota under joint sponsorship of the US Department of Energy and the US Bureau of Mines, appear superior to other, more expensive, formulations of zinc titanate and zinc ferrite which have previously been studied for multi-cycle loading (desulfurization) and regeneration (evolution of high-strength SO{sub 2} and restoration of pellet reactivity). Although these other formulations have been under development for the past twelve years, their prices still exceed $7 per pound. If manganese pellets perform as predicted in fixed bed testing, and if a significant number of utilities which burn high-sulfur coals incorporate combined-cycle gasification with hot coal gas desulfurization as a viable means of increasing conversion efficiencies, then the potential market for manganese pellets may be as high as 200,000 tons per year at a price not less than $3 per pound. This paper discusses the role of manganese pellets in the desulfurization process with respect to the integrated gasification combined-cycle (IGCC) for power generation.

  1. Regenerative Cu/La zeolite supported desulfurizing sorbents

    NASA Technical Reports Server (NTRS)

    Voecks, Gerald E. (Inventor); Sharma, Pramod K. (Inventor)

    1991-01-01

    Efficient, regenerable sorbents for removal of H2S from fluid hydrocarbons such as diesel fuel at moderate condition comprise a porous, high surface area aluminosilicate support, suitably a synthetic zeolite, and most preferably a zeolite having a free lattice opening of at least 6 Angstroms containing from 0.1 to 0.5 moles of copper ions, lanthanum ions or their mixtures. The sorbent removes sulfur from the hydrocarbon fuel in high efficiency and can be repetitively regenerated without loss of activity.

  2. Pore structure and reactivity changes in hot coal gas desulfurization sorbents. Final report, September 1987--January 1991

    SciTech Connect

    Sotirchos, S.V.

    1991-05-01

    The primary objective of the project was the investigation of the pore structure and reactivity changes occurring in metal/metal oxide sorbents used for desulfurization of hot coal gas during sulfidation and regeneration, with particular emphasis placed on the effects of these changes on the sorptive capacity and efficiency of the sorbents. Commercially available zinc oxide sorbents were used as model solids in our experimental investigation of the sulfidation and regeneration processes.

  3. Elemental sulfur recovery from desulfurization sorbents in advanced power systems

    SciTech Connect

    Dorchak, T.P.; Gangwal, S.K.; Turk, B.S.

    1995-12-31

    Regenerable metal oxide sorbents, such as zinc titanate, are being developed to efficiently remove hydrogen sulfide (H{sub 2}S) from coal gas in advanced power systems. Dilute air regeneration of the sorbents produces a tailgas containing a few percent sulfur dioxide (SO{sub 2}). Catalytic reduction of the SO{sub 2} to elemental sulfur with a coal gas slipstream using the Direct Sulfur Recovery Process (DSRP) is a leading first-generation technology. Currently the DSRP is undergoing field testing at gasifier sites. The objective of this study is to develop second-generation processes that produce elemental sulfur with limited use of coal gas. Novel approaches that were evaluated to produce elemental sulfur from sulfided sorbents include (1) SO{sub 2} regeneration, (2) substoichiometric oxidation, (3) steam regeneration followed by H{sub 2}S oxidation, and (4) steam-air regeneration. Experimental results at high temperature and high pressure demonstrate that, with simple sorbent modifications, direct regeneration to elemental sulfur is feasible without the use of coal gas.

  4. Mechanistic and kinetic studies of high-temperature coal gas desulfurization sorbents

    SciTech Connect

    Lew, S.; Flytzani-Stephanopoulos, M.; Sarofim, A.F.

    1991-10-01

    The overall objective of this project was to investigate the properties of and evaluate mixed oxides of zinc and titanium for hot fuel gas desulfurization. Uncombined ZnO was also investigated as a base case. Detailed investigation of the reduction and sulfidation reactions of Zn-Ti-O sorbents was performed. The intrinsic kinetics and the product layer diffusion rates in reduction and sulfidation were determined. Kinetic experiments with sorbents containing various Zn/Ti atomic ratios were performed. Chemical phase and structural transformations were followed by various methods. The results were compared to similar experiments performed with ZnO. The purpose of these experiments was to determine how the presence of titanium dioxide affects the reduction and sulfidation of ZnO. This information would be used to identify and select the sorbent composition that gives the best combination of low reduction rate and acceptable sulfidation performance at temperatures exceeding 600{degree}C. (VC)

  5. Durable zinc ferrite sorbent pellets for hot coal gas desulfurization

    DOEpatents

    Jha, Mahesh C.; Blandon, Antonio E.; Hepworth, Malcolm T.

    1988-01-01

    Durable, porous sulfur sorbents useful in removing hydrogen sulfide from hot coal gas are prepared by water pelletizing a mixture of fine zinc oxide and fine iron oxide with inorganic and organic binders and small amounts of activators such as sodium carbonate and molybdenite; the pellets are dried and then indurated at a high temperature, e.g., 1800.degree. C., for a time sufficient to produce crush-resistant pellets.

  6. Durable zinc oxide-containing sorbents for coal gas desulfurization

    SciTech Connect

    Siriwardane, R.V.

    1994-12-31

    Durable zinc-oxide containing sorbent pellets for removing hydrogen sulfide from a gas stream at an elevated temperature are made up to contain titania as a diluent, high-surface-area silica gel as a matrix material, and a binder. These materials are mixed, moistened, and formed into pellets, which are then dried and calcined. The resulting pellets undergo repeated cycles of sulfidation and regeneration without loss of reactivity and without mechanical degradation. Regeneration of the pellets is carried out by contacting the bed with an oxidizing gas mixture.

  7. Durable zinc oxide-containing sorbents for coal gas desulfurization

    DOEpatents

    Siriwardane, Ranjani V.

    1996-01-01

    Durable zinc-oxide containing sorbent pellets for removing hydrogen sulfide from a gas stream at an elevated temperature are made up to contain titania as a diluent, high-surface-area silica gel, and a binder. These materials are mixed, moistened, and formed into pellets, which are then dried and calcined. The resulting pellets undergo repeated cycles of sulfidation and regeneration without loss of reactivity and without mechanical degradation. Regeneration of the pellets is carried out by contacting the bed with an oxidizing gas mixture.

  8. Desulfurization characteristics of rapidly hydrated sorbents with various adhesive carrier particles for a semidry CFB-FGD system.

    PubMed

    You, Changfu; Li, Yuan

    2013-03-19

    Semidry flue gas desulfurization (FGD) experiments were conducted using rapidly hydrated sorbents with four different adhesive carrier particles: circulation ash from a circulating fluidized bed boiler (CFBB circulation ash), fly ash from the first electrical field of the electrostatic precipitator of a circulating fluidized bed boiler (CFBB ESP ash), fly ash from a chain boiler (chain boiler ash), and river sand smaller than 1 mm. The influences of various adhesive carrier particles and operating conditions on the desulfurization characteristics of the sorbents were investigated, including sprayed water, reaction temperature, and the ratio of calcium to sulfur (Ca/S). The experimental results indicated that the rapidly hydrated sorbents had better desulfurization characteristics by using adhesive carrier particles which possessed better pore, adhesion, and fluidization characteristics. The desulfurization efficiency of the system increased as the reaction temperature decreased, it improved from 35% to 90% as the mass flow rate of the sprayed water increased from 0 to 10 kg/h, and it increased from 65.6% to 82.7% as Ca/S increased from 1.0 to 2.0. Based on these findings, a new semidry circulating fluidized bed (CFB)-FGD system using rapidly hydrated sorbent was developed. Using the rapidly hydrated sorbent, this system uses a cyclone separator instead of an ESP or a bag filter to recycle the sorbent particles, thereby decreasing the system flow resistance, saving investment and operating costs of the solids collection equipment.

  9. Desulfurization characteristics of rapidly hydrated sorbents with various adhesive carrier particles for a semidry CFB-FGD system.

    PubMed

    You, Changfu; Li, Yuan

    2013-03-19

    Semidry flue gas desulfurization (FGD) experiments were conducted using rapidly hydrated sorbents with four different adhesive carrier particles: circulation ash from a circulating fluidized bed boiler (CFBB circulation ash), fly ash from the first electrical field of the electrostatic precipitator of a circulating fluidized bed boiler (CFBB ESP ash), fly ash from a chain boiler (chain boiler ash), and river sand smaller than 1 mm. The influences of various adhesive carrier particles and operating conditions on the desulfurization characteristics of the sorbents were investigated, including sprayed water, reaction temperature, and the ratio of calcium to sulfur (Ca/S). The experimental results indicated that the rapidly hydrated sorbents had better desulfurization characteristics by using adhesive carrier particles which possessed better pore, adhesion, and fluidization characteristics. The desulfurization efficiency of the system increased as the reaction temperature decreased, it improved from 35% to 90% as the mass flow rate of the sprayed water increased from 0 to 10 kg/h, and it increased from 65.6% to 82.7% as Ca/S increased from 1.0 to 2.0. Based on these findings, a new semidry circulating fluidized bed (CFB)-FGD system using rapidly hydrated sorbent was developed. Using the rapidly hydrated sorbent, this system uses a cyclone separator instead of an ESP or a bag filter to recycle the sorbent particles, thereby decreasing the system flow resistance, saving investment and operating costs of the solids collection equipment. PMID:23398211

  10. Advanced sulfur control concepts in hot-gas desulfurization technology. Quarterly report, April--June 1994

    SciTech Connect

    Harrison, D.P.

    1994-07-01

    The primary objective of this research project is the direct production of elemental sulfur during the regeneration of known high temperature desulfurization sorbents. The contract was awarded to LSU on April 12, 1994, and this quarterly report covers accomplishments during the first 2 1/2 months of the project. Effort during the initial 2 1/2 month period has been limited to Tasks 1 and 2, and involves a search of the literature to identify concepts for producing elemental sulfur during regeneration of known metal oxide sorbents and a thermodynamic evaluation of these concepts. While searching and evaluating the literature is a continuing process, concentrated effort on that phase is now complete and a detailed summary is included in this report. Three possible concepts for the direct production of elemental sulfur were identified in the LSU proposal, and the literature search has not uncovered any additional concepts. Thus, the three concepts being investigated involve: (1) regeneration with SO{sub 2}, (2) regeneration with mixtures Of 02 and H{sub 2}O, and (3) regeneration with H{sub 2}O. While concept (3) directly produces H{sub 2}S instead of elemental sulfur, the concept is included because the possibility exists for converting H{sub 2}S to elemental sulfur using the Claus process. Each of the concepts will ultimately be compared to the Direct Sulfur Recovery Process (DSRP) under development by RTI. DSRP involves initial sorbent regeneration to SO{sub 2}, and the inclusion of additional processing steps to reduce the SO{sub 2} to elemental sulfur.

  11. Durable zinc ferrite sorbent pellets for hot coal gas desulfurization

    SciTech Connect

    Jha, M.C.; Blandon, A.E.; Hepworth, M.T.

    1988-03-22

    A durable, pelletized and indurated sorbent for removing hydrogen sulfide from hot coal gas is described which consists essentially of zinc ferrite, has a surface area of about 0.5 to about 5 m./sup 2/gram, and is prepared by mixing fine iron oxide and fine zinc oxide, each having a particle size of less than about 1 micron in substantially equi-molar amounts with an inorganic binder in an amount greater than zero and up to about 15%, by weight, and an organic binder in an amount greater than zero and up to about 5%, by weight, up to about 5%, by weight, of manganese oxide, up to about 0.2%, by weight, of an alkali metal carbonate and up to about 0.2%, by weight, of molybdenite. The inorganic binder is capable of a strong bridging action between zinc ferrite particles during induration and the organic binder is capable of burning away during induration to form a porous structure, pelletizing the resulting mixture with water, drying the resulting pellets and indurating the dried pellets and a temperature of about 1600/sup 0/F to about 2000/sup 0/F to form strong, porous sorbent pellets having a crush strength of about 5 to about 20 lbs. Dead Weight Load.

  12. Hot coal gas desulfurization with manganese-based sorbents

    SciTech Connect

    Hepworth, M.T.; Ben-Slimane, R.

    1994-10-01

    In this paper, the physical and chemical behavior of several sorbent formulations fabricated from a manganese-containing compound, alundum (Al{sub 2}O{sub 3}), and a binder are addressed. The thermodynamic feasibility of hydrogen sulfide (H{sub 2}S)-removal from hot-simulated coal-gases using these sorbents and their subsequent regeneration with air are established. A formulation, FORM4-A, which consists of MnCO{sub 3}, alundum, and bentonite exhibits the best combination of capacity and reactivity; whereas, FORM1-A, which consists of Mn-ore, alundum, and dextrin exhibits the best combination of strength and reactivity. One important finding is that the capacity of the pellets for sulfur pickup from a H{sub 2}/H{sub 2}S mixture (at 950{degrees}C) and the kinetics of reduction, sulfidation and regeneration (at 1000{degrees}C) improve with recycling without compromising the strength. The leading formulation, FORM4-A, was subjected to 20 consecutive cycles of sulfidation and regeneration at 900{degrees}C in a 2-inch fixed bed reactor. The sulfidation gas was a simulated Tampella U-gas with an increased hydrogen sulfide content of 3% by volume to accelerate the rate of breakthrough, arbitrarily taken as 500 ppmv. Consistent with thermo-gravimetric analysis (TGA) on individual pellets, the fixed bed tests show small improvement in capacity and kinetics with the sulfur-loading capacity being about 22% by weight of the original pellet, which corresponds to approximately 90% bed utilization.

  13. Pore structure and reactivity changes in hot coal gas desulfurization sorbents. Technical progress report, October--December 1988

    SciTech Connect

    Sotirchos, S.V.

    1989-01-01

    A research program is proposed for the investigation of the dependence of the sorptive capacity of metal/metal oxide desulfurization sorbents on their pore size distribution and their intraparticle diffusivity. Integrated reaction/adsorption systems, chromatographic and gravimetric, will be used for successive reactivity, adsorption, and well as diffusivity, measurements. Single particle models that have been developed by our research group for gas-solid reactions with solid product will be used as basis for experimental data analysis and development of a general mathematical model for fixed-bed desulfurization and sorbent regeneration.

  14. Development of sorbents for high-temperature desulfurization in moving-bed systems

    SciTech Connect

    Ayala, R.E.; Chuck, T.; Gal, E.; Gupta, R.P.

    1994-10-01

    The objective of the option 3 program within this contract is to develop chemically reactive and mechanically durable mixed-metal oxide sorbent formulations that are suitable for moving-bed, high-temperature, desulfurization of coal gas. One optimum formulation will be evaluated in a pressurized 50-cycle bench-scale test. Work on zinc titanate formulations was initiated under the option 2 program and is continued under the present option 3 program along with testing of other mixed-metal oxides. One of the major limitations for large-scale use of mixed-metal oxides is the observed weakening and physical deterioration of the pellet and spalling during repetitive use in cycles of absorption and regeneration. A need exists to determine best operating conditions that minimize sulfate formation and prevent mechanical degradation. Results from materials tests on 5 zinc-based sorbents are given.

  15. Anion-exchange resin-based desulfurization process. Quarterly technical progress report, Januray 1, 1992--March 31, 1992

    SciTech Connect

    Sheth, A.C.; Strevel, S.D.; Dharmapurikar, R.

    1992-07-01

    Under DOE Grant No. FG22-90PC90309, the University of Tennessee Space Institute (UTSI) is contracted to further develop its anion-exchange, resin-based desulfurization concept to desulfurize alkali metal sulfates. From environmental as well as economic viewpoints, it is necessary to remove soluble sulfates from the wastes created by flue gas desulfurization systems. In order to do this economically, a low-cost desulfurization process for spent sorbents is necessary. UTSI`s anion-exchange resin-based desulfurization concept is believed to satisfy these requirements.

  16. Development of novel copper-based sorbents for hot-gas cleanup. [Quarterly] technical report, March 1, 1993--May 31, 1993

    SciTech Connect

    Hill, A.H.; Abbasian, J.; Flytzani-Stephanopoulos, M.; Li, Li

    1993-09-01

    The objective of this investigation is to evaluate two novel copper-based sorbents (i.e. copper-chromium and copper-cerium) for their effectiveness in removing hydrogen sulfide from fuel gas in the temperature range of 650{degrees} to 850{degrees}C. In this program, structural and kinetic studies are conducted on various compositions of the two selected copper-based sorbents to determine the optimum sorbent composition. The effect of operating conditions on the performance of the sorbents alone with the stability and regenerability of the selected sorbents in successive sulfidation/regeneration operation are determined. Parametric multicycle desulfurization tests were conducted this quarter in a bench-scale (5-cm-diameter) quartz reactor at one atmosphere using the CuCr{sub 2}O{sub 4} and CuO/CeO{sub 2} sorbents. The parameters studied included temperature, space velocity, and feed gas composition. Both sorbents were able to reduce the H{sub 2}S concentration of the reactor feed gas to <10 ppM under all conditions tested. The apparent reactivity of the CuO/CeO{sub 2} sorbent was lower after the first cycle which may be attributed to incomplete regeneration caused by sulfate formation.

  17. Enhanced durability of high-temperature desulfurization sorbents for moving-bed applications. Base Program: Development and testing of zinc ferrite sorbents

    SciTech Connect

    Ayala, R.E.

    1991-08-01

    The objective of this contract was to identify and test fabrication methods and sorbent chemical compositions that enhance the long-term chemical reactivity and mechanical strength of zinc ferrite and other novel sorbents for moving-bed, high-temperature desulfurization of coal-derived gases. Desired properties to be enhanced for moving-bed sorbent materials are: (1) high chemical reactivity (sulfur absorption rate and total sulfur capacity), (2) high mechanical strength (pellet crush strength and attrition resistance), and (3) suitable pellet morphology (e.g., pellet size, shape, surface area, and average specific pore volume). In addition, it is desired to maintain the sorbent properties over extended cyclic use in moving- bed systems.

  18. Advanced sulfur control concepts in hot-gas desulfurization technology: Phase 1, Feasibility of the direct production of elemental sulfur during the regeneration of high temperature desulfurization sorbents

    SciTech Connect

    Lopez, A.; White, J.; Groves, F.R.; Harrison, D.P.

    1994-10-01

    This topical report de-scribes the results of Phase 1 research performed during the first six months of a three-year contract to study the feasibility of the direct production of elemental sulfur during the regeneration of high temperature desulfurization sorbents. Much effort has gone into the development of a high-temperature meal oxide sorbent process for removal of H{sub 2}S from the coal gas. A number of sorbents based upon metals such as zinc, iron, manganese and others have been studied. In order for high temperature desulfurization to be economical it is necessary that the sorbents be regenerated to permit multicycle operation. Current methods of sorbent regeneration involve oxidation of the metal sulfide to reform the metal oxide and free the sulfur as SO{sub 2}. An alternate regeneration process in which the sulfur is liberated in elemental form is preferable. The overall objective of the current research is to study simpler and economically superior processing of known sorbents capable of producing elemental sulfur during regeneration. This topical report summarizes the first steps of this effort. A literature search has been completed to identify possible regeneration concepts and to collect relevant thermodynamic, kinetic, and process data. Three concepts involving reaction with SO{sub 2}, partial oxidation using an O{sub 2} {minus} H{sub 2}O mixture, and steam regeneration have been identified. The first two concepts result in the direct production of elemental sulfur while H{sub 2}S is the product of steam regeneration. This concept is of potential interest, however, since existing Claus technology can be used to convert H{sub 2}S to elemental sulfur. Following the literature search, a thermodynamic analysis, based upon free-energy minimization was carried out to evaluate candidate sorbents for possible use with the three regeneration concepts.

  19. Enhanced durability of high-temperature desulfurization sorbents for moving-bed applications. Option 2 Program: Development and testing of zinc titanate sorbents

    SciTech Connect

    Ayala, R.E.

    1993-04-01

    One of the most advantageous configurations of the integrated gasification combined cycle (IGCC) power system is coupling it with a hot gas cleanup for the more efficient production of electric power in an environmentally acceptable manner. In conventional gasification cleanup systems, closely heat exchangers are necessary to cool down the fuel gases for cleaning, sometimes as low as 200--300{degree}F, and to reheat the gases prior to injection into the turbine. The result is significant losses in efficiency for the overall power cycle. High-temperature coal gas cleanup in the IGCC system can be operated near 1000{degree}F or higher, i.e., at conditions compatible with the gasifier and turbine components, resulting is a more efficient overall system. GE is developing a moving-bed, high-temperature desulfurization system for IGCC power systems in which mixed-metal oxides are currently being used as desulfurization sorbents. The objective of this contract is to identify and test fabrication methods and sorbent chemical compositions that enhance the long-term chemical reactivity and mechanical durability of zinc ferrite and other novel sorbents for moving-bed, high-temperature desulfurization of coal-derived gases. Zinc ferrite was studied under the base program of this contract. In the next phase of this program novel sorbents, particularly zinc titanate-based sorbents, are being studied under the remaining optional programs. This topical report summarizes only the work performed under the Option 2 program. In the course of carrying out the program, more than 25 zinc titanate formulations have been prepared and characterized to identify formulations exhibiting enhanced properties over the baseline zinc titanate formulation selected by the US Department of Energy.

  20. Mechanistic and kinetic studies of high-temperature coal gas desulfurization sorbents. Final report, July 1988--July 1991

    SciTech Connect

    Lew, S.; Flytzani-Stephanopoulos, M.; Sarofim, A.F.

    1991-10-01

    The overall objective of this project was to investigate the properties of and evaluate mixed oxides of zinc and titanium for hot fuel gas desulfurization. Uncombined ZnO was also investigated as a base case. Detailed investigation of the reduction and sulfidation reactions of Zn-Ti-O sorbents was performed. The intrinsic kinetics and the product layer diffusion rates in reduction and sulfidation were determined. Kinetic experiments with sorbents containing various Zn/Ti atomic ratios were performed. Chemical phase and structural transformations were followed by various methods. The results were compared to similar experiments performed with ZnO. The purpose of these experiments was to determine how the presence of titanium dioxide affects the reduction and sulfidation of ZnO. This information would be used to identify and select the sorbent composition that gives the best combination of low reduction rate and acceptable sulfidation performance at temperatures exceeding 600{degree}C. (VC)

  1. Molecular biological enhancement of coal desulfurization: Cloning and expression of the sulfoxide/sulfone/sulfonate/sulfate genes in Pseudomonads and Thiobacillae. Eleventh quarterly report

    SciTech Connect

    Krawiec, S.

    1992-08-01

    Research continues on desulfurization of coal using microorganisms. Topics reported on this quarter include: desulfurization with N1-36 (presumptively identified as Rhodochrous erythropolis), pulsed-field gel electrophoresis of chromosomal DNA`s of Thiobacillus spp., and fresh isolates with the presumptive capacity to desulfurize dibenzothiophenes.

  2. (18)O(2) label mechanism of sulfur generation and characterization in properties over mesoporous Sm-based sorbents for hot coal gas desulfurization.

    PubMed

    Liu, B S; Wan, Z Y; Wang, F; Zhan, Y P; Tian, M; Cheung, A S C

    2014-02-28

    Using a sol-gel method, SmMeOx/MCM-41 or SBA-15 (Me=Fe, Co and Zn) and corresponding unsupported sorbents were prepared. The desulfurization performance of these sorbents was evaluated over a fixed-bed reactor and the effects of reaction temperature, feed and sorbent composition on desulfurization performance were studied. Samarium-based sorbents used to remove H2S from hot coal gas were reported for the first time. The results of successive sulfidation/regeneration cycles revealed that SmFeO3/SBA-15 sorbent was suitable for desulfurization of hot coal gas in the chemical industry. The formation of elemental sulfur during both sulfidation and regeneration processes depended strongly on the catalytic action of Sm2O2S species, which was confirmed for the first time via high sensitive time of flight mass spectrometer (TOF-MS) using 6%vol(18)O2/Ar regeneration gas and can reduce markedly procedural complexity. The sorbents were characterized using N2-adsorption, high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), temperature-programmed reduction of H2 (H2-TPR), thermogravimetry (TG) and time-of-flight mass spectrometry (TOF-MS) techniques.

  3. (18)O(2) label mechanism of sulfur generation and characterization in properties over mesoporous Sm-based sorbents for hot coal gas desulfurization.

    PubMed

    Liu, B S; Wan, Z Y; Wang, F; Zhan, Y P; Tian, M; Cheung, A S C

    2014-02-28

    Using a sol-gel method, SmMeOx/MCM-41 or SBA-15 (Me=Fe, Co and Zn) and corresponding unsupported sorbents were prepared. The desulfurization performance of these sorbents was evaluated over a fixed-bed reactor and the effects of reaction temperature, feed and sorbent composition on desulfurization performance were studied. Samarium-based sorbents used to remove H2S from hot coal gas were reported for the first time. The results of successive sulfidation/regeneration cycles revealed that SmFeO3/SBA-15 sorbent was suitable for desulfurization of hot coal gas in the chemical industry. The formation of elemental sulfur during both sulfidation and regeneration processes depended strongly on the catalytic action of Sm2O2S species, which was confirmed for the first time via high sensitive time of flight mass spectrometer (TOF-MS) using 6%vol(18)O2/Ar regeneration gas and can reduce markedly procedural complexity. The sorbents were characterized using N2-adsorption, high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), temperature-programmed reduction of H2 (H2-TPR), thermogravimetry (TG) and time-of-flight mass spectrometry (TOF-MS) techniques. PMID:24462892

  4. [TDA`s hot gas desulfurization sorbent]. TDA Inc./FETC CRADA No. 97-F003, final report

    SciTech Connect

    Berry, D.A.

    1997-11-14

    This report describes the results of a Cooperative Research and Development Agreement (CRADA) between TDA Incorporated and the Federal Energy Technology Center (FETC) in Morgantown, West Virginia. The objective of this CRADA was to evaluate the performance of TDA`s hot gas desulfurization (HGD) sorbent for use in fossil fuel gasification processes. This particular sorbent, TNT-MB was developed for use in moving-bed HGD reactors in an integrated gasification combined cycle (IGCC) power plant. Two separate tests were conducted; a 10-cycle test, and a low-temperature scoping test. All 10 cycles absorbed H{sub 2}S for the prescribed 125 minutes without breakthrough. The H{sub 2}S concentration remained below 50 ppmv throughout the 125 minute test period. The sorbent showed an increase in attrition resistance from 1.8% (fresh) to 0.87% (reactor inlet) and 0.64% (reactor outlet) after 10 cycles. The results of an additional attrition test are also contained in this report.

  5. Desulfurization behavior of iron-based sorbent with MgO and TiO{sub 2} additive in hot coal gas

    SciTech Connect

    Weiren Bao; Zong-you Zhang; Xiu-rong Ren; Fan Li; Li-ping Chang

    2009-07-15

    The sulfidation behaviors of iron-based sorbent with MgO and MgO-TiO{sub 2} are studied under different isothermal conditions from 623 to 873 K in a fixed bed reactor. The results of sorbents sulfidation experiments indicate that the sorbents with MgO and TiO{sub 2} additives are more attractive than those without additives for desulfurization of hot coal gas. The sulfur capacity (16.17, 18.45, and 19.68 g S/100 g sorbent) of M1F, M3F, and M5F sorbent containing 1, 3, and 5% MgO, respectively, is obviously bigger than that (15.02 g S/100 g sorbent) of M0F without additive. The feasible sulfidation temperature range for M3F sorbent is 773-873 K. The M3F sorbent is optimally regenerated at the temperature of 873 K, under the gas containing 2% oxygen, 15% steam and N{sub 2}, in the space velocity of 2500 h{sup -1}. The sorbent regenerated is also well performed in the second sulfidation (the effective sulfur capacities of 17.98 g S/100 g sorbents and the efficiency of removal sulfur of 99%). The capacity to remove sulfur decreases with steam content increasing in feeding gas from 0 to 10%, but it can restrain the formation of carbon and iron carbide. The addition of TiO{sub 2} in sorbent can shift the optimal sulfidation temperature lower. The iron-based sorbent with 3% MgO and 10% TiO{sub 2} (MFT) is active to the deep removal of H{sub 2}S and COS, especially in the temperature range of 673-723 K. The sulfur removal capacity of MFT sorbent is 21.60 g S/100 g sorbent. 16 refs., 12 figs., 8 tabs.

  6. KINETICS OF Mn-BASED SORBENTS FOR HOT COAL GAS DESULFURIZATION

    SciTech Connect

    J.J. BERNS; K.A. SADECKI; M.T. HEPWORTH

    1997-09-15

    Mixed manganese oxide sorbents have been investigated for high-temperature removal of hydrogen sulfide (the primary sulfur bearing compound) from hot coal gases. The sorbents were screened by thermodynamic equilibrium considerations for sulfidation. Preliminary experimental work using thermogravimetric analysis (TGA) indicated titania to be a superior substrate than alumina. Four formulations showing superior reactivity in a TGA were then tested in an ambient pressure fixed-bed reactor to determine steady state H 2 S concentrations, breakthrough times and effectiveness of the sorbent when subjected to cyclic sulfidation and regeneration testing. Eight tests were conducted with each test consisting of five cycles of sulfidation and regeneration. Sulfidation occurred at 600 o C using a simulated coal gas at an empty-bed space velocity of approximately 12,000 per hour. Manganese-based sorbents with molar ratios > 1:1 Mn:Substrate were effective in reducing the H 2 S concentration in simulated coal gases to less than 100 ppmv over five cycles. Actual breakthrough time for formulation C6-2-1100 was as high as 73% of breakthrough time based on wt% Mn in sorbent at 600 o C. Regeneration tests determined that loaded pellets can be essentially completely regenerated in an air/steam mixture at 750 o C with minimal sulfate formation. The leading formulation (designated C6-2) from the fixed-bed tests was then further tested under varying sorbent induration temperature, sulfidation temperature and superficial gas velocity. Four tests were conducted with each test consisting of four cycles of sulfidation and regeneration. Results showed that the induration temperature of the sorbent and the reaction temperature greatly affected the H 2 S removal capacity of the sorbent while the superficial gas velocity between 1090 and 1635 cm/min had minimal affect on the sorbent's breakthrough capacity. Testing showed that the sorbent's strength was a strong function of the sorbent induration

  7. [Reparation and desulfurization of Na2CO3/straw sorbents for removing SO2 from flue gas].

    PubMed

    Shang, Hongshan; Yang, Fan; Kou, Yuan

    2003-11-01

    A series of SO2 sorbents 5%-90% (mass percent) Na2CO3/straw were prepared by conventional incipient wetness impregnation of straw with an aqueous solution of Na2CO3. It was showed that small particle size (< or = 0.28 mm) of the straw and low flow rate (40 mL/min) of the feed gas favor the removal of SO2, while temperature (70 degrees C-300 degrees C) has little effect on the desulfurization efficiency. Based on XRD, SEM and ATR-IR analysis it can be concluded that the Na2CO3 on the surface of the straw is mainly in an amorphous state. The unique structural features of the straw and its interaction with Na2CO3 lead to the amorphous structure having greater surface area (12.14 m2/g) and pore volume (0.093 cm3/g) with a high loading of Na2CO3.

  8. Composition modification of zinc titanate sorbents for hot gas desulfurization. Technical report, March 1--May 31, 1995

    SciTech Connect

    Swisher, J.H.

    1995-12-31

    For new coal gasification systems, zinc titanate sorbents are being developed to remove sulfur from the hot product gas prior to its use in combined cycle turbines and high temperature fuel cells. Although most of the properties of these sorbents are very attractive, there are still concerns about durability over many sulfidation-regeneration cycles and zinc losses due to vaporization. Doping the zinc titanate with other metal ions could alleviate both concerns, which are the objectives of this project. After a screening study was completed, it was decided that Cr offered more promise as a dopant than Ni, Cu, Mg, and Al. Therefore six new sorbent formulations containing Cr were prepared, and they are now being evaluated with a series of bulk density, X-ray diffraction, crush strength and thermogravimetric analysis (TGA) measurements. Results to date suggest that, while Zn vaporization losses can be reduced with Cr additions, a penalty in chemical reactivity occurs. A fixed bed test was also completed this quarter on a Cr-containing formulation. The H{sub 2}S breakthrough time was about 11 hours, and utilization of Zn in the sorbent was 60.5%.

  9. KINETICS OF Mn-BASED SORBENTS FOR HOT COAL GAS DESULFURIZATION

    SciTech Connect

    K.A. SADECKI; M.T. HEPWORTH

    1997-06-15

    Manganese-based sorbents have been investigated for the removal of hydrogen sulfide (the primary sulfur bearing compound) from hot coal gases. Four formulations of Mn-based sorbents were tested in an ambient-pressure fixed-bed reactor to determine steady state H2S concentrations, breakthrough times and effectiveness of the sorbent when subjected to cyclic sulfidation and regeneration testing. In previous reports, the sulfidation and regeneration results from cyclic testing done at 550 and 600 °C were presented. Manganese-based sorbents with molar ratios > 1:1 Mn:Substrate were effective in reducing the H2S concentration in simulated coal gases to less than 100 ppmv over five cycles. Actual breakthrough time for formulation C6-2-1100 was as high as 73% of breakthrough time based on wt% Mn in sorbent at 600 °C. Regeneration tests determined that loaded pellets can be essentially completely regenerated in air/steam mixture at 750 °C with minimal sulfate formation. In this report, the performance of the leading formulation (designated C6-2) was investigated for high temperature removal of H2S from simulated coal-derived fuel gas under varying sorbent induration temperature, reaction temperature, and superficial gas velocity. Sulfidation experiments were performed in an ambient pressure fixed-bed reactor between 500 °C and 600 °C. Four tests were conducted with each test consisting of four cycles of sulfidation and regeneration. Results showed that the induration temperature of the sorbent and the reaction temperature greatly affected the H2S removal capacity of the sorbent while the superficial gas velocity between 1090 and 1635 cm/min had minimal affect on the sorbent's breakthrough capacity. Sorbent also showed 30 to 53% loss of its strength over four cycles of sulfidation and regeneration. The former being sorbent indurated at 1115 °C and the prior being sorbent indurated at 1100 °C.

  10. Testing of zinc titanate desulfurization sorbents for moving-bed applications

    SciTech Connect

    Ayala, R.E.; Gal, E.; Gupta, R.P.

    1993-09-01

    Sorbents developed for moving-bed systems must comply with a minimum of chemical and mechanical durability performance characteristics in order to be considered acceptable for long-term operation. Among the desired properties, a sorbent must have: (1) High chemical reactivity, as measured by the rate of sulfur absorption and the total sulfur loading on the sorbent. (2) High mechanical strength, as measured by the pellet crush strength and the attrition resistance; (3) Suitable pellet morphology, as given by pellet size and shape to promote good bulk flow ability and seasonable porosity to increase reactivity. Formulation 2A1.7M (UCI designation L-3787M) was selected by DOE as the baseline formulation for performance evaluation of Option 3 sorbents. This baseline formulation is a rounded zinc titanate sorbent containing a 2:1 Zn:Ti molar ratio, 1.7% molybdenum (equivalent to 2.5% MoO{sub 3}), and 3% bentonite binder that had been previously tested under the Option 2 program. Zinc titanate sorbents were prepared by UCI as rounded spherical or ellipsoidal pellets. The fabrication procedure is targeted at achieving a balance of mechanical strength (crush strength and attrition resistance) and chemical reactivity by controlling the pellet internal porosity.

  11. Anion-exchange resin-based desulfurization process. Quarterly technical progress report, January 1, 1993--March 31, 1993

    SciTech Connect

    Sheth, A.C.; Dharmapurikar, R.

    1993-06-01

    Under DOE Grant No. FG22-90PC90309, the University of Tennessee Space Institute (UTSI) is contracted to further develop its anion-exchange, resin-based desulfurization concept to desulfurize alkali metal sulfates. From environmental as well as economic viewpoints, it is necessary to remove soluble sulfates from the wastes created by flue gas desulfurization systems. In order to do this economically, a low-cost desulfurization process for spent sorbents is necessary. UTSI`s anion-exchange resin-based desulfurization concept is believed to satisfy these requirements. UTSI has completed the batch mode experiments to locate the position of the CO{sub 3}{sup 2} and SO{sub 4}{sup 2} ions in the affinity chart. Also, the reviews of the ASPEN Code`s capabilities and EPRI-TAG document`s methodology are in progress for developing the Best Process Schematic and related economics. The fixed-bed experiments are also in progress to evaluate the cycle efficiency of the candidate resins. So far we have completed ten consecutive cycles of exhaustion/carbonation and regeneration for IRA-35 resin. Because of the past problems (now resolved) with the fixed-bed system, the addition of batch mode screening experiments, Christmas holidays and spring break, and the moving of UTSI`s Chemistry Laboratory to a new location, the program is about 6--8 weeks behind schedule, but well within the budget.

  12. Molecular biology of coal bio-desulfurization; Quarterly technical progress report, October 1--December 31, 1990

    SciTech Connect

    Young, K.D.; Gallagher, J.R.

    1991-01-25

    The aim of this project is to use the techniques of molecular genetics to identify, clone, sequence, and enhance the expression of proteins which remove sulfur covalently bound to coal. This includes the movement and expression of these proteins into bacterial species which may be more useful in the industrial application of a biological desulfurization process. This quarter we finalized the initial cloning and sequencing of the dibenzothiophene (DBT) metabolic (``dox``) genes from strain C18. In addition, we constructed several mutations in single dox genes and have begun to dissect the contribution of each gene product in the DBT degradation pathway. Using a probe derived from DNA adjacent to a transposon which inactivated DBT metabolism, the DBT active genes from A15 have been cloned and identified on cosmids. We have also electroporated Thiobacillus ferrooxidans with a plasmid containing a chloramphenicol resistant transposon. Colonies of T. ferrooxidans resistant to chloramphenicol were obtained.

  13. Bench-scale testing of novel high-temperature desulfurization sorbents: Final report

    SciTech Connect

    Gangwal, S.K.; Harkins, S.M.; Stogner, J.M.; Woods, M.C.; Rogers, T.N.

    1988-12-01

    Extrudates of regenerable mixed-metal oxide sorbents including zinc ferrite, copper-modified zinc ferrite, zinc titanate, copper aluminate, copper-iron aluminate, and copper manganate were prepared and tested for their potential to remove hydrogen sulfide (H/sub 2/S) from coal gasifier gas in a high-temperature high-pressure (HTHP) fixed-bed reactor. The zinc containing sorbents were found to be more promising than those containing combinations of copper, aluminum, iron, and manganese. Reductions in H/sub 2/S concentration were achieved depending on sorbent, reactor temperature, and steam concentration. The copper-modified zinc ferrite sorbent reduced the H/sub 2/S concentration to less than 1 ppmv at up to 1100/degree/F with 20 volume % steam in the gas. The zinc ferrite sorbent showed no apparent loss in capacity over 15 sulfidation-regeneration cycles but underwent significant strength reduction in a coal-derived gas with 15% or less steam due to soot formation. Zinc titanate exhibited excellent strength and capacity retention at steam levels as low as 5% and temperatures as high as 1350/degree/F. 13 refs., 64 figs., 75 tabs.

  14. Investigation on durability and reactivity of promising metal oxide sorbents during sulfidation and regeneration. Quarterly report, April--June 1995

    SciTech Connect

    Kwon, K.C.

    1995-07-01

    Hot-gas desulfurization for the integrated gasification combined cycle (IGCC) process has been investigated by many researchers to remove effectively hydrogen sulfide with various metal oxide sorbents at high pressures and high temperatures. Metal oxides such as zinc titanate oxides, zinc ferrite oxide, copper oxide, manganese oxide and calcium oxide, were found to be promising sorbents in comparison with other removal methods such as membrane separations and reactive membrane separations. Removal reaction of H{sub 2}S from coal gas mixtures with ZT-4 or other promising sorbents of fine solid particles, and regeneration reaction of sulfur-loaded sorbents will be carried on in a batch reactor or a continuous differential reactor. The objectives of this research project are to find intrinsic initial reaction kinetics for the metal oxide-hydrogen sulfide heterogeneous reaction system, to obtain effects of concentrations of coal gas components such as hydrogen, carbon monoxide, carbon dioxide, oxygen, nitrogen and moisture on equilibrium reaction rate constants of the reaction system at various reaction temperatures and pressures, to identify regeneration kinetics of sulfur-loaded metal oxide sorbents, and to formulate promising metal oxide sorbents for the removal of sulfur from coal gas mixtures. Promising durable metal oxide sorbents of high-sulfur-absorbing capacity will be formulated by mixing active metal oxide powders with inert metal oxide powders and calcining these powder mixtures, or impregnating active metal oxide sorbents on supporting metal oxide matrixes. The Research Triangle Institute, a sub-contractor of this research project, will also prepare promising metal oxide sorbents for this research project, plan experiments on removal of sulfur compounds from coal gases with metal oxide sorbents as well as regeneration of sulfur-loaded metal oxide sorbents, and review experimental results.

  15. Bench-scale demonstration of hot-gas desulfurization technology. Quarterly report, October 1 - December 31, 1994

    SciTech Connect

    1994-12-31

    The U.S. Department of Energy (DOE), Morgantown Energy Technology Center (METC), is sponsoring research in advanced methods for controlling contaminants in hot coal gasifier gas (coal gas) streams of integrated gasification combined-cycle (IGCC) power systems. The programs focus on hot-gas particulate removal and desulfurization technologies that match or nearly match the temperatures and pressures of the gasifier, cleanup system, and power generator. The work seeks to eliminate the need for expensive heat recovery equipment, reduce efficiency losses due to quenching, and minimize wastewater treatment costs. Hot-gas desulfurization research has focused on regenerable mixed-metal oxide sorbents which can reduce the sulfur in coal gas to less than 20 ppmv and can be regenerated in a cyclic manner with air for multicycle operation. Zinc titanate (Zn{sub 2}TiO{sub 4} or ZnTiO{sub 3}), formed by a solid-state reaction of zinc (ZnO) and titanium dioxide (TiO{sub 2}), is currently one of the leading sorbents. This report summarizes the highlights and accomplishments of the October slipstream test run of the Zinc Titanate Fluid Bed Desulfurization/Direct Sulfur Recovery Process (ZTFBD/DSRP) Mobile Laboratory at the Department of Energy`s Morgantown Energy Technology Center. Although the run had to be shortened due to mechanical problems with METC`s gasifier, there was sufficient on-stream time to demonstrate highly successful operation of both the zinc titanate fluid bed desulfurization and the DSRP with actual coal gas.

  16. INVESTIGATION ON DURABILITY AND REACTIVITY OF PROMISING METAL OXIDE SORBENTS DURING SULFIDATION AND REGENERATION. QUARTERLY AND FINAL REPORT

    SciTech Connect

    K.C. KWON

    1998-08-01

    Hot-gas desulfurization for the integrated gasification combined cycle (IGCC) process has been investigated by many researchers to remove effectively hydrogen sulfide with various metal oxide sorbents at high pressures and high temperatures. Metal oxides such as zinc titanate oxides, zinc ferrite oxide, copper oxide, manganese oxide and calcium oxide, were found to be promising sorbents in comparison with other removal methods such as membrane separations and reactive membrane separations. Some metal oxide sorbents exhibited the quite favorable performance in terms of attrition resistance and sulfur capacity. Experiments on removal reaction of H{sub 2}S from coal gas mixtures with formulated metal oxide sorbents were conducted in a batch reactor or a differential reactor. The objectives of this research project are to formulate promising metal oxide sorbents for removal of sulfur from coal gas mixtures, to find initial reaction kinetics for the metal oxide-hydrogen sulfide heterogeneous reaction system, to obtain effects of hydrogen, nitrogen and moisture on dynamic absorption and equilibrium absorption at various absorption temperatures. Promising durable metal oxide sorbents with high-sulfur-absorbing capacity were formulated by mixing active metal oxide powders with inert metal oxide powders, and calcining these powder mixtures. The Research Triangle Institute (RTI), a sub-contractor of this research project, will also prepare promising metal oxide sorbents for this research project, plan experiments on removal of sulfur compounds from coal gases with metal oxide, and review experimental results.

  17. Enhanced durability of high-temperature desulfurization sorbents for moving-bed applications

    SciTech Connect

    Ayala, R.E.; Gal, E.; Gupta, R.P.

    1992-11-01

    Chemical reactivity was determined at GECRD by measuring sorbent sulfur loading (defined as grams of sulfur absorbed per 100 g of fresh sorbent) in fresh and in cycled samples from a bench-scale reactor. Only formulations that exhibited a good balance of chemical and mechanical performance as fresh pellets were selected for further cyclic testing in the benchscale reactor system. Details of the bench-scale reactor and procedures have been given before (Ayala, 1991). The important aspect of the benchscale testing is that both absorption and regeneration were conducted in a packed-bed reactor simulating the time/temperature environment to which the sorbent would be exposed in a typical cycle of the full-scale moving-bed system. Absorption was carried out at 1000{degrees}F using any of three gas compositions, all having a deliberately high H{sub 2}S concentration (1 %) to accelerate testing. The oxidative regeneration was carried out between 1000 and 1250{degrees}F and 1--21% oxygen during the early phases of regeneration, and at 1400{degrees}F during the final phase simulating the temperature rise of the sorbent bed. Sixteen zinc titanate formulations were prepared as cylindrical extrudates. For all formulations, the calcination time was held constant at 2 hours. The following results were obtained: Formulations containing a 0.8 Zn:Ti ratio produced mixtures of several stoichiometric titanates: Zn{sub 2}Ti{sub 3}O{sub 8}, ZnTiO{sub 3}, and Zn{sub 2}TiO{sub 4}, with the relative amount of each depending on temperature. Formulations containing a 2.0 Zn:Ti ratio exhibited exclusively the Zn{sub 2}TiO{sub 4} structure. The higher calcination temperature of 1800{degrees}F significantly reduced the porosity available for chemical reactivity, while the lower calcination temperature of 1400{degrees}F produced, in some cases, formulations with traces of residual unreacted zinc oxide and anatase titanium dioxide.

  18. Enhanced durability of high-temperature desulfurization sorbents for moving-bed applications

    SciTech Connect

    Ayala, R.E.; Gal, E.; Gupta, R.P.

    1992-01-01

    Chemical reactivity was determined at GECRD by measuring sorbent sulfur loading (defined as grams of sulfur absorbed per 100 g of fresh sorbent) in fresh and in cycled samples from a bench-scale reactor. Only formulations that exhibited a good balance of chemical and mechanical performance as fresh pellets were selected for further cyclic testing in the benchscale reactor system. Details of the bench-scale reactor and procedures have been given before (Ayala, 1991). The important aspect of the benchscale testing is that both absorption and regeneration were conducted in a packed-bed reactor simulating the time/temperature environment to which the sorbent would be exposed in a typical cycle of the full-scale moving-bed system. Absorption was carried out at 1000[degrees]F using any of three gas compositions, all having a deliberately high H[sub 2]S concentration (1 %) to accelerate testing. The oxidative regeneration was carried out between 1000 and 1250[degrees]F and 1--21% oxygen during the early phases of regeneration, and at 1400[degrees]F during the final phase simulating the temperature rise of the sorbent bed. Sixteen zinc titanate formulations were prepared as cylindrical extrudates. For all formulations, the calcination time was held constant at 2 hours. The following results were obtained: Formulations containing a 0.8 Zn:Ti ratio produced mixtures of several stoichiometric titanates: Zn[sub 2]Ti[sub 3]O[sub 8], ZnTiO[sub 3], and Zn[sub 2]TiO[sub 4], with the relative amount of each depending on temperature. Formulations containing a 2.0 Zn:Ti ratio exhibited exclusively the Zn[sub 2]TiO[sub 4] structure. The higher calcination temperature of 1800[degrees]F significantly reduced the porosity available for chemical reactivity, while the lower calcination temperature of 1400[degrees]F produced, in some cases, formulations with traces of residual unreacted zinc oxide and anatase titanium dioxide.

  19. LIFAC sorbent injection desulfurization demonstration project. Final report, volume II: Project performance and economics

    SciTech Connect

    1996-01-01

    This publication discusses the demonstration of the LIFAC sorbent injection technology at Richmond Power and Light`s Whitewater Valley Unit No. 2, performed under the auspices of the U.S. Department of Energy`s (DOE) Clean Coal Technology Program. LIFAC is a sorbent injection technology capable of removing 75 to 85 percent of a power plant`s SO{sub 2} emissions using limestone at calcium to sulfur molar ratios of between 2 and 2.5 to 1. The site of the demonstration is a coal-fired electric utility power plant located in Richmond, Indiana. The project is being conducted by LIFAC North America (LIFAC NA), a joint venture partnership of Tampella Power Corporation and ICF Kaiser Engineers, in cooperation with DOE, RP&L, and Research Institute (EPRI), the State of Indiana, and Black Beauty Coal Company. The purpose of Public Design Report Volume 2: Project Performance and Economics is to consolidate, for public use, the technical efficiency and economy of the LIFAC Process. The report has been prepared pursuant to the Cooperative Agreement No. DE-FC22-90PC90548 between LIFAC NA and the U.S. Department of Energy.

  20. Investigation on durability and reactivity of promising metal oxide sorbents during sulfidation and regeneration. Quarterly report, October--December 1994

    SciTech Connect

    Kwon, K.C.

    1995-01-01

    Hot-gas desulfurization for the integrated gasification combined cycle (IGCC) process has been investigated by many researchers to remove effectively hydrogen sulfide with various metal oxide sorbents at high pressures and high temperatures. Metal oxides such as zinc titanate oxides, zinc ferrite oxide, copper oxide, manganese oxide and calcium oxide, were found to be promising sorbents in comparison with other removal methods such as membrane separations and reactive membrane separations. Some metal oxide sorbents exhibited the quite favorable performance in terms of attrition resistance and sulfur capacity. Removal reaction of H{sub 2}S from coal gas mixtures with ZT-4 or other promising sorbents of fine solid particles, and regeneration reaction of sulfur-loaded sorbents will be carried on in a batch reactor or a continuous differential reactor. The objectives of this research project are to find intrinsic initial reaction kinetics for the metal oxide-hydrogen sulfide heterogeneous reaction system, to obtain effects of concentrations of coal gas components such as hydrogen, carbon monoxide, carbon dioxide, oxygen, nitrogen and moisture on equilibrium reaction rate constants of the reaction system at various reaction temperatures and pressures, to identify regeneration kinetics of sulfur-loaded metal oxide sorbents, and to formulate promising metal oxide sorbent for the removal of sulfur from coal gas mixtures. Promising durable metal oxide sorbents of high-sulfur-absorbing capacity will be formulated by mixing active metal oxide powders with inert metal oxide powders and calcining these powder mixtures, or impregnating active metal oxide sorbents on supporting metal oxide matrixes.

  1. Desulfurization of coal with hydroperoxides of vegetable oils. [Quarterly] report, September 1--November 30, 1994

    SciTech Connect

    Smith, G.V.; Gaston, R.D.; Song, Ruozhi; Cheng, Jianjun

    1994-12-31

    This project proposes a new method for removing organic sulfur from Illinois coals using readily available farm products. It proposes to use air and vegetable oils to disrupt the coal matrix, oxidize sulfur forms, increase volatiles, and desulfurize coal. This will be accomplished by impregnating coals with polyunsaturated oils, converting the oils to their hydroperoxides, and heating. Since these oils are relatively inexpensive and easily applied, this project could lead to a cost effective method for removing organic sulfur from coals. Moreover, the oils are environmentally safe; they will produce no noxious products and will improve burning qualities of the solid products. Preliminary experiments showed that EBC 104 coal catalyzes the formation of hydroperoxides in safflower oil and that more sulfur is extracted from the treated than untreated coal. During this first quarter the requirement of an added photosensitizer has been eliminated, the catalytic effect of coal has been confirmed, and the existence of a complex set of reactions revealed. These reactions between the oxygen, oil, hydroperoxides, and coal are hydroperoxide formation, which is catalyzed by the coal surface and by heat, an unknown coal-hydroperoxide reaction, and oil polymerization. Additionally, diffusion phenomena must be playing a role because oil polymerization occurs, but the importance of diffusion is difficult to assess because less polymerization occurs when coal is present. The first task has been completed and we are now ready to determine the ability of linseed oil hydroperoxides to oxidize organic sulfur in EBC 108 coal.

  2. Porous desulfurization sorbent pellets containing a reactive metal oxide and an inert zirconium compound

    SciTech Connect

    Gardner, Todd H.; Gasper-Galvin, Lee D.

    1996-12-01

    Sorbent pellets for removing hydrogen sulfide from coal gas are prepared by combining a reactive oxide, in particular zinc oxide, with a zirconium compound such as an oxide, silicate, or aluminate of zirconium, and an inorganic binder and pelletizing and calcining the mixture. Alternately, the zinc oxide may be replaced by copper oxide or a combination of copper, molybdenum, and manganese oxides. The pellet components may be mixed in dry form, moistened to produce a paste, and converted to pellets by forming an aqueous slurry of the components and spray drying the slurry, or the reactive oxide may be formed on existing zirconium-containing catalyst-carrier pellets by infusing a solution of a salt of the active metal onto the existing pellets and firing at a high temperature to produce the oxide. Pellets made according to this invention show a high reactivity with hydrogen sulfide and durability such as to be useful over repeated cycles of sorption and regeneration.

  3. A calcium oxide sorbent process for bulk separation of carbon dioxide. Quarterly progress report 19, January--March, 1994

    SciTech Connect

    Harrison, D.P.

    1994-04-01

    This research project is investigating the technical feasibility of a high-temperature, high-pressure (HTHP) process for the bulk separation of CO{sub 2} from coal-derived gas. Indirect evidence which suggested that the water-gas shift reaction occurred simultaneously with CO{sub 2} removal was found. Occurrence of the simultaneous reactions created the possibility of a direct one-step process for the manufacture of hydrogen from coal-gas while at the same time separating a concentrated stream of CO{sub 2}. Previous quarterly reports have described the design, construction, and commissioning of the fixed-bed reactor, development of analytical procedures, and results of a number of tests using dolomite sorbent precursor. During the current quarter, additional tests were carried out to study the effects of calcination gas composition, temperature, and space velocity using the standard dolomite sorbents. Alternate sorbents were tested to provide direct comparison of dolomite and limestone performance. Tests were performed using an empty reactor and reactor packed with commercial shift catalyst to learn more of the characteristics of the shift reaction in the absence of carbonation. Toward the end of the quarter, emphasis changed to sorbent durability and a number of multicycle tests were completed.

  4. Bench-scale demonstration of hot-gas desulfurization technology. Quarterly report, January 1--March 31, 1998

    SciTech Connect

    1998-12-31

    At the start of the current project, the DSRP (Direct Sulfur Recovery Process) technology was at the bench-scale development stage with a skid-mounted system ready for field testing. The process had been extended to fluidized-bed operation in the Stage 1 reactor. A preliminary economic study for a 100 MW plant in which the two-stage DSRP was compared to conventional processes indicated the economic attractiveness of the DSRP. Through bench-scale development, both fluidized-bed zinc titanate and DSRP technologies have been shown to be technically and economically attractive. The demonstrations prior to the start of this project, however, had only been conducted using simulated (rather than real) coal gas and simulated regeneration off-gas. Thus, the effect of trace contaminants in real coal gases on the sorbent and DSRP catalyst was not known. Also, the zinc titanate desulfurization unit and DSRP had not been demonstrated in an integrated manner. The overall goal of this project is to continue further development of the zinc titanate desulfurization and DSRP technologies by scale-up and field testing (with actual coal gas) of the zinc titanate fluidized-bed reactor system, and the Direct Sulfur Recovery Process.

  5. LIFAC sorbent injection desulfurization demonstration project. Quarterly report No. 3, April--June 1991

    SciTech Connect

    Not Available

    1991-12-31

    LIFAC combines upper-furnace limestone injection followed by post-furnace humidification in an activation reactor located between the air preheater and the ESP. The process produces a dry and stable waste product that is partially removed from the bottom of the activation reactor and partially removed at the ESP.

  6. Formation of (FexMn(2-x))O3 solid solution and high sulfur capacity properties of Mn-based/M41 sorbents for hot coal gas desulfurization.

    PubMed

    Zhang, Y; Liu, B S; Zhang, F M; Zhang, Z F

    2013-03-15

    Several MCM-41 materials were synthesized at different conditions by hydrothermal procedure using cheap and easily available industrial water glass as silica source. Fe doped manganese-based oxide/MCM-41 sorbents were prepared by a sol-gel method. The effects of loadings of metal oxide, Fe/Mn molar ratios over MCM-41 and reaction temperature on the performance of sorbent for hot coal gas desulfurization were investigated. Various techniques such as BET, XRD, XPS, LRS and HRTEM were used to characterize the sorbents. The result indicated Fe(3+) ions could occupy a position of Mn(3+) in cubic lattice of Mn2O3 and the (FexMn2-x)O3 solid solution is mainly active phase of sorbent. Moreover, the result of nine successive sulfurization-regeneration cycles of sorbent showed high sulfur adsorption capacity and endurable stability of FeMn4Ox/MCM-41 for H2S removal.

  7. Formation of (FexMn(2-x))O3 solid solution and high sulfur capacity properties of Mn-based/M41 sorbents for hot coal gas desulfurization.

    PubMed

    Zhang, Y; Liu, B S; Zhang, F M; Zhang, Z F

    2013-03-15

    Several MCM-41 materials were synthesized at different conditions by hydrothermal procedure using cheap and easily available industrial water glass as silica source. Fe doped manganese-based oxide/MCM-41 sorbents were prepared by a sol-gel method. The effects of loadings of metal oxide, Fe/Mn molar ratios over MCM-41 and reaction temperature on the performance of sorbent for hot coal gas desulfurization were investigated. Various techniques such as BET, XRD, XPS, LRS and HRTEM were used to characterize the sorbents. The result indicated Fe(3+) ions could occupy a position of Mn(3+) in cubic lattice of Mn2O3 and the (FexMn2-x)O3 solid solution is mainly active phase of sorbent. Moreover, the result of nine successive sulfurization-regeneration cycles of sorbent showed high sulfur adsorption capacity and endurable stability of FeMn4Ox/MCM-41 for H2S removal. PMID:23337625

  8. Performance of a novel synthetic Ca-based solid sorbent suitable for desulfurizing flue gases in a fluidized bed

    SciTech Connect

    Pacciani, R.; Muller, C.R.; Davidson, J.F.; Dennis, J.S.; Hayhurst, A.N.

    2009-08-05

    The extent and mechanism of sulfation and carbonation of limestone, dolomite, and chalk, were compared with a novel, synthetic sorbent (85 wt % CaO and 15 wt % Ca{sub 12}A{sub l14}O{sub 33}), by means of experiments undertaken in a small, electrically heated fluidized bed. The sorbent particles were used either (I) untreated, sieved to two particle sizes and reacted with two different concentrations of SO{sub 2}, or (ii) after being cycled 20 times between carbonation, in 15 vol % CO{sub 2} in N2, and calcination, in pure N2, at 750 degrees C. The uptake of untreated limestone and dolomite was generally low (<0.2 g(SO{sub 2})/g(sorbent)), confirming previous results, However, the untreated chalk and the synthetic sorbent were found to be substantially more reactive with SO{sub 2}, and their final uptake was significantly higher (>0.5 g(SO{sub 2})/g(sorbent)) and essentially independent of the particle size. Here, comparisons are made on the basis of the sorbents in the calcined state. The capacities for the uptake of SO{sub 2}, on a basis of unit mass of calcined sorbent, were comparable for the chalk and the synthetic sorbent. However, previous work has demonstrated the ability of the synthetic sorbent to retain its capacity for CO{sub 2} over many cycles of carbonation and calcination: much more so than natural sorbents such as chalk and limestone. Accordingly, the advantage of the synthetic sorbent is that it could be used to remove CO{sub 2} from flue gases and, at the end of its life, to remove SO{sub 2} on a once-through basis.

  9. Molecular biology of coal bio-desulfurization. Quarterly technical progress report, January 1--March 31, 1992

    SciTech Connect

    Young, K.D.; Gallagher, J.R.

    1992-04-30

    Genes cloned from Rhodococcus rhodochrous IGTS8 can transfer the DBT desulfurization phenotype to a different species (R. Fascians). The product was identified as 2-phenylphenol by gas chromatography. This result parallels the results we have previously reported for the activity of these genes in a DBT-negative mutant of IGTS8. Thus, the evidence is strong that we have identified and cloned the entire set of genes that are responsible for this very specific desulfurization reaction. Sequencing of these genes has commenced. A genomic library was constructed from the bacterium, Besulfovibrio desulfuricans. Screening has not yet identified a clone that carries the desulfurization genes from that organism. Two open reading frames, doxH and doxJ, in the C18 DBT degradation pathway were mutated and are now believed to be dispensable to that pathway. Finally, progress was made toward beginning to sequence the DBT dixoygenase genes from strain A15.

  10. Management of dry flue gas desulfurization by-products in underground mines. Quarterly report, October 1--December 31, 1995

    SciTech Connect

    1997-05-01

    On September 30, 1993, the U.S. Department of Energy - Morgantown Energy Technology Center (DOE-METC) and Southern Illinois University at Carbondale (SITJC) entered into a cooperative research agreement entitled {open_quotes}Management of Dry Flue Gas Desulfurization By-Products in Underground Mines{close_quotes} (DE-FC21-93MC-30252). Under the agreement SIUC will develop and demonstrate two technologies for the placement of coal combustion by-products in abandoned underground coal mine workings, and assess the environmental impact of such underground placements. This report discusses the technical progress achieved during the period October 1 - December 31, 1995. Rapid Aging Test columns were placed in operation during the second quarter of 1995, and some preliminary data were acquired during this quarter. These data indicate that the highly caustic pH is initially generated in the pneumatic mix, but that such pH is short lived. The initial pH rapidly declines to the range of 8 to 9. Leachates in this pH range will have little or no effect on environmental concerns. Dedicated sampling equipment was installed in the groundwater monitoring wells at the proposed placement site at the Peabody Number 10 mine. Also, the groundwater monitoring wells were {open_quotes}developed{close_quotes} during the quarter to remove the fines trapped in the sand pack and screen. A new procedure was used in this process, and proved successful. A series of tests concerning the geotechnical characteristics of the pneumatic mixes were conducted. Results show that both moisture content and curing time have a direct effect on the strength of the mixes. These are, of course, the expected general results. The Christmas holidays and the closing of the University during an extended period affected the progress of the program during the quarter. However, the program is essentially on schedule, both technically and fiscally, and any delays will be overcome during the first quarter of 1996.

  11. Hot coal gas desulfurization with manganese-based sorbents. Progress report, April 1, 1993--June 30, 1993

    SciTech Connect

    Hepworth, M.T.

    1993-07-15

    Focus of work is primarily in use of zinc ferrite and zinc titanate sorbents; however, an alternate sorbent, manganese dioxide-containing ore in mixture with alumina (75 wt % ore + 25 wt % Al{sub 2}O{sub 3}) may be a viable alternative to zinc-based sorbents. Manganese, for example, has a lower vapor pressure in the elemental state than zinc, hence it is not as likely to undergo depletion from the sorbent surface upon loading and regeneration cycles. Also manganese oxide is less readily reduced to the elemental state than iron hence the range of reduction potentials for oxygen is somewhat greater than for zinc ferrite. Thermodynamic analysis of the system shows it to be less amenable to sulfation than zinc ferrite. Potential also exists for utilization of manganese higher temperatures than zinc ferrite or titanate. This report gives the thermodynamic background for consideration of manganese-based sorbents as an alternative to zinc ferrite. To date the work is limited to thermogravimetric testing of four formulations of manganese-alumina sorbents to determine the optimum conditions of pelletization and enduration to produce reactive pellets.

  12. Enzymatic desulfurization of coal. Fourth quarterly report, March 16--June 15, 1989

    SciTech Connect

    Boyer, Y.N.; Crooker, S.C.; Kitchell, J.P.; Nochur, S.V.; Marquis, J.K.

    1989-06-16

    Our current efforts to develop clean coal technology emphasize the advantages of enzymatic desulfurization techniques and have specifically addressed the potential of using partially-purified extracellular microbial enzymes as well as commercially available enzymes. Our work is focused on the treatment of ``model`` organic sulfur compounds such as dibenzothiophene (DBT) and ethylphenylsulfide (EPS). Furthermore, we are designing experiments to facilitate the enzymatic process by means of a hydrated organic solvent matrix.

  13. Enzymatic desulfurization of coal. First quarterly report, May 5--September 30, 1988

    SciTech Connect

    Marquis, J.K.; Kitchell, J.P.

    1988-10-07

    Our current efforts to develop clean coal technology, emphasize the advantages of enzymatic desulfurization techniques and have specifically addressed the potential of using partially-purified extracellular microbial enzymes or commercially available enzymes. Our work is focused on the treatment of ``model`` organic sulfur compounds such as dibenzothiophene (DBT) and ethylphenylsulfide (EPS). Furthermore, we are designing experiments to facilitate the enzymatic process by means of a hydrated organic solvent matrix.

  14. Enzymatic desulfurization of coal. Second quarterly report, October 1--December 15, 1988

    SciTech Connect

    Marquis, J.K.; Kitchell, J.P.

    1988-12-15

    Our current efforts to develop clean coal technology emphasize the advantages of enzymatic desulfurization techniques and have specifically addressed the potential of using partially-purified extracellular microbial enzymes or commercially available enzymes. Our work is focused on the treatment of ``model`` organic sulfur compounds such as dibenzothiophene (DBT) and ethylphenylsulfide (EPS). Furthermore, we are designing experiments to facilitate the enzymatic process by means of a hydrated organic solvent matrix.

  15. Desulfurization of coal: enhanced selectivity using phase transfer catalysts. Quarterly report, March 1 - May 31, 1996

    SciTech Connect

    Palmer, S.R.; Hippo, E.J.

    1996-12-31

    Due to environmental problems related to the combustion of high sulfur Illinois coal, there continues to be interest in the development in viable pre-combustion desulfurization processes. Recent studies by the authors have obtained very good sulfur removals but the reagents that are used are too expensive. Use of cheaper reagents leads to a loss of desired coal properties. This study investigated the application phase transfer catalysts to the selective oxidation of sulfur in coal using air and oxygen as oxidants. The phase transfer catalyst is expected to function as a selectivity moderator by permitting the use of milder reaction conditions that otherwise necessary. This would enhance the sulfur selectivity and help retain the heating value of the coal. The use of certain coal combustion wastes for desulfurization, and the application of cerium (IV) catalyzed air oxidation for selective sulfur oxidation are also being studied. If successful, this project could lead to the rapid development of a commercially viable desulfurization process. This would significantly improve the marketability of Illinois coal.

  16. Kinetics of MN-based sorbents for hot coal gas desulfurization. Semiannual report, December 15, 1996--March 15, 1997

    SciTech Connect

    Hepworth, M.T.

    1997-03-01

    Manganese-based sorbents have been investigated for the removal of hydrogen sulfide (the primary sulfur bearing compound) from hot coal gases prior to its use in combined cycle turbines. Four formulations of Mn-based sorbents were tested in an ambient-pressure fixed-bed reactor to determine steady state H{sub 2}S concentrations, breakthrough times and effectiveness of the sorbent when subjected to cyclic sulfidation and regeneration testing. In previous reports, the sulfidation and regeneration results from cyclic testing done at 600{degrees}C were presented. Manganese-based sorbents with molar ratios >1:1 Mn:substrate were effective in reducing the H{sub 2}S concentration in simulated coal gases to less than 100 ppmv over five cycles. Actual breakthrough time for formulation C6-2-1100 was as high as 73% of breakthrough time based on wt% Mn in sorbent. Regeneration tests determined that loaded pellets can be fully regenerated in air/steam mixture at 750{degrees}C with minimal sulfate formation. In this report, the results from the cyclic crush strength tests, sulfur profile test, and cyclic testing done after 5 cycles showed decreases in strength from 12.6% to 57.9%. Cyclic testing at 550{degrees}C showed pre-breakthrough concentrations as low as 10 ppmv. Cyclic testing done at 2 L/min and 3 L/min did not show any significant difference in pre-breakthrough concentrations or capacity.

  17. Management of dry flue gas desulfurization by-products in underground mines. Quarterly report, October--December 1994

    SciTech Connect

    Chugh, Y.; Dutta, D.; Esling, S.; Ghafoori, N.; Paul, B.; Sevim, H.; Thomasson, E.

    1995-01-01

    On September 30, 1993, the US Department of Energy, Morgantown Energy Technology Center and Southern Illinois University at Carbondale (SIUC) entered into a cooperative agreement entitled ``Management of Dry Flue Gas Desulfurization By-Products in Underground Mines`` (DE-FC21-93MC30252). Under the agreement, Southern Illinois University at Carbondale will develop and demonstrate several technologies for the placement of coal combustion residues in abandoned coal mines, and will assess the environmental impact of such underground residues placement. The major event during the quarter was the demonstration of the SEEC, Inc. technology for loading and transporting coal combustion residues in the SEEC developed Collapsible Intermodal Containers (CIC). The demonstration was held on November 17, 1994, at the Illinois Power Company Baldwin power plant, and was attended by about eighty (80) invited guest. Also during the quarter meetings were held with Peabody Coal Company officials to finalize the area in the Peabody No. 10 mine to be used for the placement of coal combustion residues. Work under the Materials Handling and Systems Economics area continued, particularly in refining the costs and systems configuration and in economic evaluation of various systems using equipment leasing rather than equipment purchases. Likewise, work progressed on residues characterization, with some preparations being made for long-term testing.

  18. Desulfurization of coal with hydroperoxides of vegetable oils. [Quarterly progress report], December 1, 1994--February 28, 1995

    SciTech Connect

    Smith, G.V.; Gaston, R.D.; Song, Ruozhi; Cheng, Jianjun; Shi, Feng; Gholson, K.L.; Ho, K.K.

    1995-12-31

    This project proposes a new method for removing organic sulfur from Illinois coals using readily available farm products. It proposes to use air and vegetable oils to disrupt the coal matrix, oxidize sulfur forms, increase volatiles, and desulfurize coal. This will be accomplished by impregnating coals with polyunsaturated oils, converting the oils to their hydroperoxides, and heating. Since these oils are relatively inexpensive and easily applied, this project could lead to a cost effective method for removing organic sulfur from coals. Moreover, the oils are environmentally safe; they will produce no noxious products and will improve burning qualities of the solid products. Preliminary experiments showed that IBC 104 coal catalyzes the formation of hydroperoxides in safflower oil and that more sulfur is extracted from the treated than untreated coal. During the first quarter the requirement of an added photosensitizer was eliminated, the catalytic effect of coal was confirmed, and the existence of a complex set of reactions was revealed. During this second quarter working with IBC-108 coal (2.3% organic S. 0.4% pyrite S), the effects of different ratios of oil:coal, different extraction solvents, and different temperatures were examined. A new pretreatment which combines alkali with linseed oil was discovered. Best organic sulfur removal is approximately 26% using alkali pretreatment combined with linseed oil at 1OO{degree}C. BTU loses can be kept to a minimum of 3% with proper use of solvents.

  19. Management of dry flue gas desulfurization by-products in underground mines. Quarterly technical progress report, April 1995--June 1995

    SciTech Connect

    Chugh, Y.P.; Dutta, D.; Esling, S.

    1995-07-01

    On September 30, 1993, the U.S. Department of Energy-Morgantown Energy Technology Center and Southern Illinois University at Carbondale (SIUC) entered into a cooperative research agreement entitled {open_quotes}Management of Dry Flue Gas Desulfurization By-Products in Underground Mines{close_quotes} (DE-FC21-93MC30252). Under the agreement Southern Illinois University at Carbondale will develop and demonstrate several technologies for the placement of coal combustion residues in abandoned coal mines, and will assess the environmental impact of such underground residues placement. Previous quarterly Technical Progress Reports have set forth the specific objectives of the program, and a discussion of these is not repeated here. Rather, this report discusses the technical progress made during the period April 1 - June 30, 1995. A final topical report on the SEEC, Inc. demonstration of its technology for the transporting of coal combustion residues was completed during the quarter, although final printing of the report was accomplished early in July, 1995. The SEEC technology involves the use of Collapsible Intermodal Containers (CIC`s) developed by SEEC, and the transportation of such containers - filled with fly ash or other coal combustion residues - on rail coal cars or other transportation means. Copies of the final topical report, entitled {open_quotes}The Development and Testing of Collapsible Intermodal Containers for the Handling and Transport of Coal Combustion Residues{close_quotes} were furnished to the Morgantown Energy Technology Center. The Rapid Aging Test colums were placed in operation during the quarter. This test is to determine the long-term reaction of both the pneumatic and hydraulic mixtures to brine as a leaching material, and simulates the conditions that will be encountered in the actual underground placement of the coal combustion residues mixtures. The tests will continue for about one year.

  20. Reduction of spalling in mixed metal oxide desulfurization sorbents by addition of a large promoter metal oxide

    DOEpatents

    Poston, James A.

    1997-01-01

    Mixed metal oxide pellets for removing hydrogen sulfide from fuel gas mixes derived from coal are stabilized for operation over repeated cycles of desulfurization and regeneration reactions by addition of a large promoter metal oxide such as lanthanum trioxide. The pellets, which may be principally made up of a mixed metal oxide such as zinc titanate, exhibit physical stability and lack of spalling or decrepitation over repeated cycles without loss of reactivity. The lanthanum oxide is mixed with pellet-forming components in an amount of 1 to 10 weight percent.

  1. Reduction of spalling in mixed metal oxide desulfurization sorbents by addition of a large promoter metal oxide

    DOEpatents

    Poston, J.A.

    1997-12-02

    Mixed metal oxide pellets for removing hydrogen sulfide from fuel gas mixes derived from coal are stabilized for operation over repeated cycles of desulfurization and regeneration reactions by addition of a large promoter metal oxide such as lanthanum trioxide. The pellets, which may be principally made up of a mixed metal oxide such as zinc titanate, exhibit physical stability and lack of spalling or decrepitation over repeated cycles without loss of reactivity. The lanthanum oxide is mixed with pellet-forming components in an amount of 1 to 10 weight percent.

  2. Enzymatic desulfurization of coal. Fifth quarterly report, June 16--September 15, 1989

    SciTech Connect

    Boyer, Y.N.; Crooker, S.C.; Kitchell, J.P.; Nochur, S.V.; Marquis, J.K.

    1989-11-07

    Our experimental approach focuses on the use of enzymes which catalyze the addition of oxygen to organic compounds. In tailoring the application of these enzymes to coal processing, we are particularly interested in ensuring that oxidation occurs at sulfur and not at carbon-carbon bonds. Previous studies with DBT have shown that the reaction most frequently observed in microbial oxidative pathways is one in which DBT is oxidized at ring carbons. These reactions, as we have said, are accompanied by a considerable decrease in the energy content of the compound. In addition, microbial pathways have been identified in which the sulfur atom is sequentially oxidized to sulfoxide, to sulfone, to sulfonate, and finally to sulfuric acid. In this case, the fuel value of the desulfurized compounds is largely retained. We are evaluating the potential of commercially available enzymes to selectively catalyze oxidation at sulfur.

  3. Enzymatic desulfurization of coal. Seventh quarterly report, December 16, 1989--March 15, 1990

    SciTech Connect

    Boyer, Y.N.; Crooker, S.C.; Kitchell, J.P.; Nochur, S.V.

    1990-03-23

    Our experimental approach focuses on the use of enzymes which catalyze the addition of oxygen to organic compounds. In tailoring the application of these enzymes to coal processing, we are particularly interested in ensuring that oxidation occurs at sulfur and not at carbon-carbon bonds. Previous studies with DBT have shown that the reaction most frequently observed in microbial oxidative pathways is one in which DBT is oxidized at ring carbons. These reactions, as we have said, are accompanied by a considerable decrease in the energy content of the compound. In addition, microbial pathways have been identified in which the sulfur atom is sequentially oxidized to sulfoxide, to sulfone, to sulfonate, and finally to sulfuric acid. In this case, the fuel value of the desulfurized compounds is largely retained. We are evaluating the potential of commercially available enzymes to perform this function.

  4. Effects of CO and CO₂ on the desulfurization of H₂S using a ZnO sorbent: a density functional theory study.

    PubMed

    Ling, Lixia; Zhao, Zhongbei; Wang, Baojun; Fan, Maohong; Zhang, Riguang

    2016-04-28

    The density functional theory (DFT) method has been performed to study the effects of CO and CO2 on the desulfurization of H2S over a ZnO sorbent. It shows that COS is inevitably formed on the ZnO(101¯0) surface, which tends to be adsorbed onto the surface via a S-C bond binding with either a long or a short Zn-O bond. Potential energy profiles for the COS formation via reactions between H2S and CO, and H2S and CO2 on the ZnO(101¯0) surface have been constructed. In the presence of CO, the dissociated active S of H2S reacting with CO leads to the formation of COS, and the activation energy of the rate-determining step is 87.7 kJ mol(-1). When CO2 is present, the linear CO2 is first transferred to active CO2 in a triplet state, and then combines with active S to form COS with the highest energy barrier of 142.4 kJ mol(-1). Rate constants at different temperatures show that the formation of COS via the reaction of CO and H2S is easier than that of CO2 and H2S over the ZnO surface. PMID:27048981

  5. Management of dry flue gas desulfurization by-products in underground mines. Quarterly report, July 1 - September 30, 1996

    SciTech Connect

    1996-12-31

    On September 30, 1996, the U.S. Department of Energy-Morgantown Energy Technology Center and Souther Illinois University at Carbondale (SIUC) entered into a cooperative research agreement entitled ``Management of Dry Flue Gas Desulfurization By-Products in Underground Mines``. Under the agreement SIUC will develop and demonstrate two technologies for the placement of coal combustion by-products in abandoned underground coal mines, and will assess the environmental impact of these technologies for the management of coal combustion by-products. The two technologies for the underground placement that will be developed and demonstrated are: (1) pneumatic placement, using virtually dry materials, and (2) hydraulic placement, using a ``paste`` mixture of materials with about 70% solids. Phase II of the overall program began April 1, 1996. The principal objective of Phase II is to develop and fabricate the equipment for both the pneumatic and hydraulic placement technologies, and to conduct a surface demonstration-test of both technologies. During the current quarter the main thrust was to develop the equipment necessary for the program. Shop drawings were completed for the pneumatic placement equipment, and purchase orders issued for many of the component parts. The final pneumatic placement system will be assembled in the SIUC Carterville facility.

  6. Management of dry flue gas desulfurization by-products in underground mines. Quarterly report, April 1--June 30, 1996

    SciTech Connect

    1997-05-01

    On September 30, 1993, the US Department of Energy - Morgantown Energy Technology Center (DOE-METC) and Southern Illinois University at Carbondale (SIUC) entered into a cooperative research agreement entitled {open_quotes}Management of Dry Flue Gas Desulfurization By-Products in Underground Mines{close_quotes} (DE-FC21-93MC30252). Under the agreement Southern Illinois University at Carbondale will develop and demonstrate two technologies for the placement of coal combustion residues in abandoned underground coal mines, and will assess the environmental impact of these technologies for the management of coal combustion by-products. The two technologies for the underground placement that will be developed and demonstrated are: (1) pneumatic placement, using virtually dry materials, and (2) hydraulic placement, using a {open_quotes}paste{close_quotes} mixture of materials with about 70% solids. Phase II of the overall program began April 1, 1996. The principal objective of Phase II is to develop and fabricate the equipment for placing the coal combustion by-products underground, and to conduct a demonstration of the technologies on the surface. Therefore, this quarter has been largely devoted to developing specifications for equipment components, visiting fabrication plants throughout Southern Illinois to determine their capability for building the equipment components in compliance with the specifications, and delivering the components in a timely manner.

  7. Fluidized-bed sorbents

    SciTech Connect

    Gangwal, S.K.; Gupta, R.P.

    1994-10-01

    The objectives of this project are to identify and demonstrate methods for enhancing long-term chemical reactivity and attrition resistance of zinc oxide-based mixed metal-oxide sorbents for desulfurization of hot coal-derived gases in a high-temperature, high-pressure (HTHP) fluidized-bed reactor. In this program, regenerable ZnO-based mixed metal-oxide sorbents are being developed and tested. These include zinc ferrite, zinc titanate, and Z-SORB sorbents. The Z-SORB sorbent is a proprietary sorbent developed by Phillips Petroleum Company (PPCo).

  8. Kinetics of MN based sorbents for hot coal gas. Quarterly report, September--December 1996

    SciTech Connect

    1996-12-31

    Manganese-based sorbents have been investigated for the removal of hydrogen sulfide (the primary sulfur bearing compound) from hot coal gases prior to its use in combined cycle turbines. Four formulations of Mn-based sorbents were tested in an ambient-pressure fixed-bed reactor to determine steady state H{sub 2}S concentrations, breakthrough times and effectiveness of the sorbent when subjected to cyclic sulfidation and regeneration testing. In a previous report, the sulfidation results were presented. Manganese-based sorbents with molar ratios > 1:1 Mn:Substrate were effective in reducing the H{sub 2}S concentration in simulated coal gases to less than 100 ppmv over five cycles. Actual breakthrough time for formulation C6-2-1100 was as high as 73% of breakthrough time based on wt% Mn in sorbent. In this report, the regeneration results will be presented. Regeneration tests determined that loaded pellets can be fully regenerated in air/steam mixture at 750{degrees}C with minimal sulfate formation. 16 refs., 9 figs., 5 tabs.

  9. Advanced sulfur control concepts for hot gas desulfurization technology. Quarterly report, October--December 1995

    SciTech Connect

    1996-01-01

    In the area of gas analysis, most of the attention during the past quarter was devoted to gaining an understanding of the operation of the Antek total sulfur analyzer, and making appropriate modifications in the unit. The primary problem is that the resistance of the capillary flow restrictor is not large enough, and the amount of sulfur which reaches the UV-analyzer results in the analyzer becoming saturated. We have added a N{sub 2} diluent flow downstream of the pyrotube tube which, we believe, will permit the unit to be operated at pressures to about 50 psig. Use of larger diluent flow rates to permit higher pressure operation is not feasible since larger diluent rates increase the back pressure on the quartz pyrotube (which operates at 1050{degrees}C) to unsafe levels. In the meantime, Antek is studying the redesign of the capillary flow restrictor to provide larger flow resistance. Studies on the regeneration of FeS in the atmospheric pressure reactor were almost completed during the quarter. Only a series of multicycle sulfidation-regeneration tests remains. The effects of reactive gas mol fraction and temperature have been examined using both O{sub 2}/N{sub 2} and H{sub 2}O/N{sub 2} atmospheres. The initial rate of regeneration was found to be a weak function of temperature and first-order in both O{sub 2} and H{sub 2}O concentration. In a test series in which the reactive gas contained both O{sub 2} and H{sub 2}O, the experimental initial rate was effectively equal to the sum of the individual initial rates, suggesting that the two reactions proceed independently of one another. Detailed correlation and statistical analysis of the data is currently being done. Principal effort during the quarter using the high pressure electrobalance was devoted to studying the regeneration of FeS in a H{sub 2}O/N{sub 2} atmosphere.

  10. Development of regenerable copper-based sorbents for hot gas cleanup. Technical report, September 1, 1995--November 30, 1995

    SciTech Connect

    Abbasian, J.; Slimane, R.B.; Hill, A.H.

    1995-12-31

    The overall objective of this study is to determine the effectiveness of the copper-chromite sorbent (developed in previous ICCI-funded projects) for longer duration application under optimum conditions in the temperature range of 550{degrees}-650{degrees}C to minimize sorbent reduction and degradation during the cyclic process. To achieve this objective, several formulations of copper chromite sorbents are prepared. These sorbent formulations are screened for their desulfurization and regeneration capability at predetermined temperatures and gas residence times. The durability of the best sorbent formulation identified in the screening tests is evaluated in ``long-term`` durability tests conducted at the optimum operating conditions. This includes testing the sorbent in pellet and granular forms in packed- and fluidized-bed reactors. During this quarter, twenty one copper chromite-based sorbent formulations were prepared. Two sorbent formulations that have acceptable crush strength, designated as CuCr-10 and CuCr-21, were tested over 5 and 6 cycles respectively. The results indicate that both sorbents are reactive toward H{sub 2}S at 650{degrees}C and that the reactivity of the sorbents are relatively constant over the first 5 to 6 cycles. The H{sub 2}S prebreakthrough concentrations were generally about 20 to 30 ppm, making them suitable for IGCC application.

  11. Evaluation of various additives on the preparation of rice husk ash (RHA)/CaO-based sorbent for flue gas desulfurization (FGD) at low temperature.

    PubMed

    Dahlan, Irvan; Lee, Keat Teong; Kamaruddin, Azlina Harun; Mohamed, Abdul Rahman

    2009-01-15

    This paper examines the effectiveness of 10 additives toward improving SO2 sorption capacities (SSC) of rice husk ash (RHA)/lime (CaO) sorbent. The additives examined are NaOH, CaCl2, LiCl, NaHCO3, NaBr, BaCl2, KOH, K2HPO4, FeCl3 and MgCl2. Most of the additives tested increased the SSC of RHA/CaO sorbent, whereby NaOH gave highest SSC (30mg SO2/g sorbent) at optimum concentration (0.25mol/l) compared to other additives examined. The SSC of RHA/CaO sorbent prepared with NaOH addition was also increases from 17.2 to 39.5mg SO2/g sorbent as the water vapor increases from 0% RH to 80% RH. This is probably due to the fact that most of additives tested act as deliquescent material, and its existence increases the amount of water collected on the surface of the sorbent, which played an important role in the reaction between the dry-type sorbent and SO2. Although most of the additives were shown to have positive effect on the SSC of the RHA/CaO sorbent, some were found to have negative or insignificant effect. Thus, this study demonstrates that proper selection of additives can improve the SSC of RHA/CaO sorbent significantly. PMID:18462871

  12. Improvement of the desulfurization and regeneration properties through the control of pore structures of the Zn-Ti-based H2S removal sorbents.

    PubMed

    Jung, Suk Yong; Jun, Hee Kwon; Lee, Soo Jae; Lee, Tae Jin; Ryu, Chong Kul; Kim, Jae Chang

    2005-12-01

    To improve the sulfur removing capacity of the conventional Zn-Ti-based H2S removal sorbents, a new Zn-Ti based sorbent (ZT-cp) was prepared by the coprecipitation method and tested in a packed bed reactor at middle temperature conditions (H2S absorption at 480 degrees C, regeneration at 580 degrees C). The new Zn-Ti-based sorbent showed excellent sulfur removing capacity without deactivation, even after 10 cycles of absorption and regeneration. The conventional Zn-Ti-based sorbents (ZT-700, ZT-1000), however, that were prepared by physical mixing, were continuously deactivated. In particular, the initial sulfur removing capacity of the ZT-cp sorbent showed a very high absorption value (0.22 g S/g sorbent), which corresponded to 91.6% of theoretical absorption amount. These results can be explained by the difference in physical properties such as pore volume, surface area, and particle size. It was also found that the sulfides formed from the ZT-cp and ZT-1000 sorbents with spinel structure were easily regenerated even at 580 degrees C. Those from the ZT-700 sorbent, with separated ZnO and TiO2 structures, needed a temperature higher than 610 degrees C for regeneration.

  13. Development of durable mixed-metal oxide sorbents for high-temperature desulfurization of coal gases in moving-bed reactors

    SciTech Connect

    Ayala, R.E.; Jain, S.C.

    1993-06-01

    Mixed-metal oxide sorbents, particularly zinc ferrite and zinc titanate, are being developed for use in hot gas cleanup of coal gas in the integrated gasification combined-cycle (IGCC). For the case of moving-bed systems, the pelletized sorbent moves between the absorber and regenerator as it absorbs H{sub 2}S from coal gas and is regenerated under diluted air. Therefore a mechanically strong and chemically active sorbent is necessary for proper long-term operation of the system. These desired properties depend on the active components in the sorbent, the type and concentration of the binder material, and the sorbent preparation procedure. In the current program, several zinc titanate sorbent formulations have been prepared using a new rounding fabrication procedure, and varying the types of additives/binders (e.g., bentonite and molybdenum) and calcination temperature (1450-1800 {degree}F, 788-982 {degree}C). Comparison with baseline cylindrical formulations was made by measuring attrition resistance, crush strength, thermogravimetric reactivity and bench-scale reactor performance.

  14. Anion-exchange resin-based desulfurization process. Quarterly technical progress report, April 1, 1993--June 30, 1993

    SciTech Connect

    Sheth, A.C.; Dharmapurikar, R.

    1993-09-01

    Under the current grant (No. DE-FG22-90PC90309), the University of Tennessee Space Institute (UTSI) will perform the bench scale evaluation and further development of the anion-exchange resin-based desulfurization concept to desulfurize alkali metal sulfates. The developmental program proposed under this DOE grant includes screening of commercially available resins to select three candidate resins for further study. These three resins will undergo a series of experiments designed to test the resins` performance under different process conditions (including the use of spent MHD seed material). The best of these resins will be used in optimizing the regeneration step and in testing the effects of performance enhancers. During this reporting period, April 1, 1993 to June 30, 1993, the procedure to evaluate the cycle efficiency of candidate resins in the fixed-bed mode was slightly modified to ensure complete regeneration of the exhausted resin. Using this revised procedure, ten consecutive cycles for all the three resins have been completed and the results are being analyzed.

  15. Theoretical approach for enhanced mass transfer effects in-duct flue gas desulfurization processes. Volume 1, Dry sorbent injection: Final report

    SciTech Connect

    Jozewicz, W.; Rochelle, G.T.

    1992-01-29

    This report presents the results of fundamental mass transfer testing for in-duct removal of SO{sub 2}. Following this initial part of an experimental program, it became clear that the amount of initial moisture on the sorbent strongly affected the extent of Ca(OH){sub 2} conversion. Novel techniques aimed at increasing sorbent utilization were investigated and are described. Major novel technique investigated and reported on here was the reaction with SO{sub 2} of sorbents with initial free moisture (damp sorbents). The duct injection process using damp solids has the following steps: preparation of sorbent as a slurry, blending of the slurry with dry recycle materials to create damp solids, injection of the solids into the duct, reaction and drying of the solids with flue gas in the duct, collection in particulate control equipment, and finally recycle of dry solids with some bleed to disposal. The moisture content of the solids at each step affects system performance. Various factors favor high moisture whereas others favor low moisture. (VC)

  16. Interactions between trace metals, sodium and sorbents in combustion. Quarterly report No. 4, July 1, 1995--September 30, 1995

    SciTech Connect

    Wendt, J.O.L.; Davis, S.

    1995-10-15

    The proposed research is directed at an understanding of how to exploit interactions between sodium, toxic metals and sorbents, in order to optimize sorbents injection procedures, which can be used to capture and transform these metals into environmentally benign forms. The research will use a 17kW downflow, laboratory combustor, to yield data that can be interpreted in terms of fundamental kinetic mechanisms. Metals to be considered are lead, cadmium, and arsenic. Sorbents will be kaolinite, bauxite, and limestone. The role of sulfur will also be determined.

  17. Anion-exchange resin-based desulfurization process

    SciTech Connect

    Sheth, A.C.; Strevel, S.D.; Dharmapurikar, R.

    1992-01-01

    Under DOE Grant No. FG22-90PC90309, the University of Tennessee Space Institute (UTSI) is contracted to further develop its anion-exchange, resin-based desulfurization concept to desulfurize alkali metal sulfates. From environmental as well as economic viewpoints, it is necessary to remove soluble sulfates from the wastes created by flue gas desulfurization systems. In order to do this economically, a low-cost desulfurization process for spent sorbents is necessary. UTSI's anion-exchange resin-based desulfurization concept is believed to satisfy these requirements.

  18. Stabilization and/or regeneration of spent sorbents from coal gasification. [Quarterly] technical report, March 1, 1992--May 31, 1992

    SciTech Connect

    Abbasian, J.; Hill, A.H.; Wangerow, J.R.

    1992-10-01

    The objective of this investigation is to determine the effects of SO{sub 2} partial pressure and reaction temperature on the conversion of sulfide containing solid wastes from coal gasifiers to stable and environmentally acceptable calcium sulfate, while preventing the release of sulfur dioxide through undesirable side reactions during the stabilization step. An additional objective of this program is to investigate the use of the Spent Sorbent Regeneration Process (SSRP) to regenerate spent limestone, from a fluidized-bed gasifier with in-bed sulfur capture, for recycling to the gasifier. To achieve these objectives, selected samples of partially sulfided sorbents will be reacted with oxygen at a variety of operating conditions under sufficient S0{sub 2} partial pressure to prevent release of sulfur from the solids during stabilization that reduces the overall sorbent utilization. Partially sulfided limestone will also be regenerated with water using the SSRP to produce calcium hydroxide and release sulfur as H{sub 2}S. The regenerated sorbent will be dewatered, dried and pelletized. The reactivity of the regenerated sorbent toward H{sub 2}S will also be determined.

  19. Stabilization and/or regeneration of spent sorbents from coal gasification. [Quarterly] technical report, December 1, 1991--February 29, 1992

    SciTech Connect

    Abbasian, J.; Hill, A.H.; Wangerow, J.R.

    1992-08-01

    The objective of this investigation is to determine the effects of SO, partial pressure and reaction temperature on the conversion of sulfide containing solid wastes from coal gasifiers to stable and environmentally acceptable calcium-sulfate, while preventing the release of sulfur dioxide through undesirable side reactions during the stabilization step. An additional objective of this program is to investigate the use of the Spent Sorbent Regeneration Process (SSRP) to regenerate spent limestone, from a fluidized-bed gasifier with in-bed sulfur capture, for recycling to the gasifier. To achieve these objectives, selected samples of partially sulfided sorbents will be reacted with oxygen at a variety of operating conditions under sufficient S0{sub 2} partial pressure to prevent release of sulfur from the solids during stabilization that reduces the overall sorbent utilization. Partially sulfided limestone will also be regenerated with water to produce calcium hydroxide and release sulfur as H{sub 2}S. The regenerated sorbent will be dewatered, dried and pelletized. The reactivity of the regenerated sorbent toward H{sub 2}S will also be determined.

  20. Effect of solids concentration distribution on the flue gas desulfurization process

    SciTech Connect

    Jie Zhang; Changfu You; Haiying Qi; Changhe Chen; Xuchang Xu

    2006-06-15

    A dry flue gas desulfurization (FGD) process at 600-800{sup o}C was studied in a pilot-scale circulating fluidized bed (CFB) experimental facility. Various fresh sorbent distribution types and internal structures were modeled numerically to investigate their effect on the gas-solid flow and sulfate reaction characteristics. Experimental results show that, after the fresh sorbent supply was stopped, the desulfurization efficiency declined rapidly even though the sorbent recirculation was maintained. Therefore, the fresh sorbent is the main contributor to the desulfurization process and the primary effect of the recirculated sorbent was to evenly distribute the fresh sorbent and to prolong the sorbent particle residence time. The numerical results demonstrate that the desulfurization efficiency varied greatly for the various fresh sorbent bottom injection methods. The desulfurization efficiency of the bottom-even injection method was 1.5 times that of the bottom two-sided injection method. Internal structures effectively improved the fresh sorbent solids concentration distribution and the desulfurization efficiency. Optimized internal structures increased the desulfurization efficiency of the bottom two-sided injection method by 46%, so that it was very close to that of the bottom-even injection method with only a 4.6% difference. 16 refs., 6 figs., 2 tabs.

  1. Biocatalytic desulfurization

    SciTech Connect

    Monticello, D.J. )

    1994-02-01

    Biocatalytic desulfurization (BDS) has many advantages compared to traditional refinery desulfurization processes, including: lower capital and operating costs, low-temperature and low-pressure operation and no hydrogen requirement. Biotechnology has developed from an art into a science in recent years. The HPI is familiar with an artful' application of biotechnology in the biotreatment of refinery wastes, and has experimented with other technologies for over 50 years. This paper discusses the following: biorefining, sulfur management, conventional solutions, bioprocessing precedents, new biotechnology tools, microbial desulfurization, biocatalytic desulfurization, specificity, biodesulfurization conceptual design, development issues, and implementation.

  2. Desulfurization of Illinois coals with hydroperoxides of vegetable oils and alkali, Quarterly report, March 1 - May 31, 1996

    SciTech Connect

    Smith, G.V.; Gaston, R.D.; Song, R.; Cheng, J.; Shi, F.; Wang, Y.

    1996-12-31

    Organic sulfur is removed from coals by treatment with aqueous base, air, and vegetable oils with minimal loss of BTU. Such results were revealed during exploratory experiments on an ICCI funded project to remove organic sulfur from Illinois coals with hydroperoxides of vegetable oils. In fact, prewashing IBC-108 coal with dilute alkali prior to treating with linseed oil and air results in 26% removal of sulfur. This new method is being investigated by treating coals with alkali, impregnating coals with polyunsaturated oils, converting the oils to their hydroperoxides, and heating. Since these oils are relatively inexpensive and easily applied, this project could lead to a cost effective method for removing organic sulfur from coals. During the first quarter the selection of base fro pretreatment and extraction was completed. NaOH is better than NH{sub 4}OH for the pretreatment and Na{sub 2}CO{sub 3} is better than NaOH for the oil extraction. During the second quarter the effectiveness of linseed oil and NaOH for sulfur removal from IBC-108 coal was further tested by pretreating the coal with two base concentrations at four different times followed by treatment with linseed oil at 125{degrees}C for three different times and finally washing with 5% Na{sub 2}CO{sub 3} and methanol. During this third quarter more experimental parameters were systematically varied in order to study the effectiveness of linseed oil and NaOH for sulfur removal from IBC- 108 coal.

  3. Development of novel copper-based sorbents for hot-gas cleanup. [Quarterly] technical report, September 1--November 30, 1993

    SciTech Connect

    Abbasian, J.; Hill, A.H.; Flytzani-Stephanopoulos, M.; Li Li

    1994-03-01

    The objective of this investigation is to evaluate two novel copper-based sorbents, namely copper-chromium and copper-cerium, for their effectiveness in removing hydrogen sulfide from fuel gas in the temperature range of 650{degree} to 850{degree}C. Such high temperatures will be required for the new generation of gas turbines (inlet >750{degree}C) in Integrated Gasification Combined Cycle (IGCC) systems. The effect of pre-reduction on the performance of the sorbents as well as the rate of different reactions occurring in cyclic sulfidation/regeneration, were studied in a thermogravimetric analyzer (TGA). Sulfidation was conducted with and without H{sub 2} and H{sub 2}O, and with and without pre-reduction in H{sub 2} or H{sub 2}/H{sub 2}O. The results of these tests indicate that reduction and regeneration of both sorbents occurs rapidly. Sulfidation of CuCr{sub 2}O{sub 4}, in H{sub 2}O-free and H{sub 2}-/H{sub 2}O-free gas indicates the possible sulfidation of both copper and chromium. Small quantities of SO{sub 2}, were released during sulfidation suggesting the possible oxidation of H{sub 2}S by the sorbent. Regeneration of the CuCr{sub 2}O{sub 4} was complete while regeneration of the CuO-CeO{sub 2} indicated possible limited sulfate formation.

  4. Coal desulfurization in a rotary kiln combustor. Quarterly report No. 1, April 16, 1990--July 15, 1990

    SciTech Connect

    Cobb, J.T. Jr.

    1990-08-15

    BCR National Laboratory (BCRNL) has initiated a project aimed at evaluating the technical and economic feasibility of using a rotary kiln, suitably modified, to burn Pennsylvania anthracite wastes, co-fired with high-sulfur bituminous coal. Limestone will be injected into the kiln for sulfur control, to determine whether high sulfur capture levels can be achieved with high sorbent utilization. The principal objectives of this work are: (1) to prove the feasibility of burning anthracite refuse, with co-firing of high-sulfur bituminous coal and with limestone injection for sulfur emissions control, in a rotary kiln fitted with a Universal Energy International (UEI) air injector system; (2) to determine the emissions levels of SO{sub x} and NO{sub x} and specifically to identify the Ca/S ratios that are required to meet New Source Performance Standards; (3) to evaluate the technical and economic merits of a commercial rotary kiln combustor in comparison to fluidized bed combustors; and, (4) to ascertain the need for further work, including additional combustion tests, prior to commercial application, and to recommend accordingly a detailed program towards this end.

  5. Pyrite surface characterization and control for advanced fine coal desulfurization technologies. Ninth quarterly technical progress report, September 1, 1992-- December 31, 1992

    SciTech Connect

    Wang, X.H.; Leonard, J.W.; Parekh, B.K.; Jiang, C.L.

    1992-12-31

    This is the 9th quarterly technical progress report for the project entitled ``Pyrite surface characterization and control for advanced fine coal desulfurization technologies``, DE-FG22-90PC90295. The work presented in this report was performed from September 1, 1992 to November 31, 1992. The objective of the project is to conduct extensive fundamental studies on the surface chemistry of pyrite oxidation and flotation and to understand how the alteration of the coal-pyrite surface affects the efficiency of pyrite rejection in coal flotation. During this reporting period, the surface oxidation of pyrite in various electrolytes was investigated. It has been demonstrated, for the first time, that borate, a pH buffer and electrolyte used by many previous investigators in studying sulfide mineral oxidation, actively participates in the surface oxidation of pyrite. In borate solutions, the surface oxidation of pyrite is tronly enhanced. The anodic oxidation potential of pyrite is lowered by more than 0.4 volts. The initial reaction of the borate enhanced pyrite oxidation can be described by:FeS{sub 2} + B(OH){sub 4}{sup =} ------> [S{sub 2}Fe-B(OH){sub 4}]{sub surf} + e. This reaction is irreversible and is controlled by the mass-transfer of borate species from the solution to the surface. It has been shown that the above reaction inhibits the adsorption of xanthate on pyrite. Comparative studies have been made with other sulfide minerals. The solution chemistry of the iron-borate systems have been studied to understand the electrochemical results.

  6. High-volume, high-value usage of flue gas desulfurization (FGD) by-products in underground mines: Phase 1 -- Laboratory investigations. Quarterly report, July--September 1995

    SciTech Connect

    1996-01-01

    Efforts primarily focused on Subtask 2.2, Chemical and Mineralogical Characterization and Subtask 4.3, Selection and Testing of Transport System. As part of Subtask 2.2, samples were collected from the Freeman United Crown Mine III FBC disposal facility representing a verity of ages and weathering. A laboratory scale transport system has been built at the CAER to evaluate the potential of pneumatic transport for flue gas desulfurization material (FGDM) emplacement and to provide essential data for the mine emplacement demonstration as part of the Subtask 4.3 effort. The system is modeled after shotcreting systems and has the advantage that the material can be remotely placed without the need for forms. The test program is focusing on determining the pneumatic conditions necessary to maximize the strength of the emplaced FGDM under anticipated mine curing conditions while minimizing dust formation. Work on Subtask 4.1, Mine Selection, also proceeded during the quarter. A new mine site, located in the south-central section of the Pikeville quadrangle, Pike County, Kentucky, was examined for the field study. The proposed fill site is in the Middle Pennsylvanian Breathitt Formation Middle Amburgy coal bed, a coal previously mined by Costain elsewhere on the property. Efforts on Subtask 4.2, Hydrologic Monitoring Plan, focused primarily on theoretical issues concerning the effects of the mining and backfill activity on the ground water and surface water due to uncertainties in the location of the final field site. There are three major concerns about the effects of the mining activity: changes in the ground water flow field, changes in ground water quality, and consequential induced changes on stream flow.

  7. Advanced sulfur control concepts in hot-gas desulfurization technology. Quarterly technical progress report, July--September 1995

    SciTech Connect

    Harrison, D.P.

    1995-10-01

    Both the Antek total sulfur analyzer and the modifications to the Shimadzu GC-14A gas chromatograph to be used for analysis for SO{sub 2} and H{sub 2}S were delivered during the quarter. Problems were faced during the installation and calibration phases of both instruments. By the end of the quarter we believe that the GC problems have been solved, but problems remain with the Antek analyzer. It appears that too much sulfur (as SO{sub 2}) reaches the UV detector and causes it to become saturated. This shows up as a maximum in the instrument calibration curve. At 200 psia, the capillary flow restrictor allows a total flow rate of about 180 sccm, and the maximum occurs at about 1 % H{sub 2}S in the calibration gas. Reducing the pressure so that the total flow is reduced to about 25 sccm shifts the calibration curve maximum to about 5.7% H{sub 2}S. It appears that we must reduce the total flow rate to the detector or provide additional dilution. This may be accomplished by increasing the resistance of the capillary restrictor, by diverting a portion of the flow leaving the pyrotube to vent, or adding an inert such as N{sub 2} to the gases exiting the pyrotube. We are in contact with Antek representatives about the problem. Both the atmospheric pressure and high pressure electrobalances were used during the quarter to study the regeneration of FeS in atmospheres of O{sub 2}/N{sub 2} or H{sub 2}O/N{sub 2}. In the atmospheric pressure unit the effects of temperature (600 - 800{degrees}C), flow rate (130 - 500 sccm), and reactive gas mol fraction (0.005 to 0.03 O{sub 2} and 0.1 to 0.5 H{sub 2}O) are being studied. Regeneration tests completed to date in the high pressure unit have utilized only O{sub 2}/N. and the parameters studied include temperature (600 - 800{degrees}C), flow rate (500 - 1000 sccm), pressure (1 - 15 atm) ad O{sub 2} mol fraction (0.005 - 0.03).

  8. Management of dry flue gas desulfurization by-products in underground mines. Quarterly report, August 1--October 31, 1997

    SciTech Connect

    Chugh, Y.P.

    1997-12-31

    The objective of this project was to develop and demonstrate two technologies for the placement of coal combustion by-products in abandoned underground coal mines, and to assess the environmental impact of these technologies for the management of CCB materials. The two technologies for the underground placement that were to be developed and demonstrated are: (1) pneumatic placement using virtually dry CCB products, and (2) hydraulic placement using a paste mixture of CCB products with about 70% solids. The period covered by this report is the second quarter of Phase 3 of the overall program. During this period over 8,000 tons of CCB mixtures was injected using the hydraulic paste technology. This amount of material virtually filled the underground opening around the injection well, and was deemed sufficient to demonstrate fully the hydraulic injection technology. By the end of this quarter about 2,000 tons of fly ash had been placed underground using the pneumatic placement technology. While the rate of injection of about 50 tons per hour met design criteria, problems were experienced in the delivery of fly ash to the pneumatic demonstration site. The source of the fly ash, the Archer Daniels Midland Company power plant at Decatur, Illinois is some distance from the demonstration site, and often sufficient tanker trucks are not available to haul enough fly ash to fully load the injection equipment. Further, on some occasions fly ash from the plant was not available. The injection well was plugged three times during the demonstration. This typically occurred due to cementation of the FBC ash in contact with water. After considerable deliberations and in consultation with the technical project officer, it was decided to stop further injection of CCB`s underground using the developed pneumatic technology.

  9. Development of novel copper-based sorbents for hot gas cleanup. Technical report, December 1, 1992--February 28, 1993

    SciTech Connect

    Hill, A.H.; Abbasian, J.; Flytzani-Stephanopoulos, M.; Bo, L.; Li, Li.; Honea, F.I.

    1993-05-01

    The objective of this investigation is to evaluate two novel copper-based sorbents (i.e. copper-chromium and copper-cerium) for their effectiveness in removing hydrogen sulfide from fuel gas in the temperature range of 650{degree} to 850{degree}C. New sorbent compositions from the selected Cu-Cr-O and Cu-Ce-O binary oxides were prepared and characterized by BET N{sub 2}-desorption surface area measurement following various calcination/time-temperature exposures. The general trends reported last quarter (on 11 different compositions) were validated this quarter in that both binary oxides lose surface area as the amount of CuO is increased. Time-resolved sulfidation tests were conducted at 850{degree}C using the equimolar CuO.Cr{sub 2}O{sub 3} composition. The two selected binary oxides prepared in larger qauntities (for testing in a two-inch reactor) have physical properties typical of the sorbents prepared in past programs. Two multicycle desulfurization tests, conducted this quarter on the Cu-Ce-O sorbent at 850{degree}C, using a feed gas containing 5000 ppm H{sub 2}S, 10 vol % H{sub 2} and 10 vol % H{sub 2}O at a space velocity (STP) of 2000 h{sup {minus}1}, demonstrated high sulfur removal efficiency for the first one or two cycles, and a significant reduction in efficiency in the following cycles.

  10. A calcium oxide sorbent process for bulk separation of carbon dioxide. Quarterly progress report, October--December 1991

    SciTech Connect

    Silaban, A.; Narcida, M.; Harrison, D.P.

    1992-02-01

    The expected commercialization of coal gasification technology in the US and world-wide will create a need for advanced gas purification and separation processes capable of operating at higher temperatures and in more hostile environments than is common today. For example, a high-temperature, high-pressure process capable of separating CO{sub 2} from coal-derived gas may find application in purifying synthesis gas for H{sub 2}, NH{sub 3}, or CH{sub 3}OH production. High temperature CO{sub 2} removal has the potential for significantly improving the operating efficiency of integrated gasification-molten carbonate fuel cells for electric power generation. This study proved the technical feasibility of a CO{sub 2}-separation process based upon the regenerable noncatalytic gas-solid reaction between CaO and CO{sub 2} to form CACO{sub 3}. Such a process operating at 650{degree}C and 15 atm with 15% CO{sub 2} in the coal gas has the potential for removing in excess of 99% of the CO{sub 2} fed. Selection of a sorbent precursor which, upon calcination, produces high-porosity CaO is important for achieving rapid and complete reaction. The addition of magnesium to the sorbent appears to improve the multicycle durability at a cost of reduced CO{sub 2} capacity per unit mass of sorbent. Reaction conditions, principally calcination and carbonation temperatures, are important factors in multicycle durability. Reaction pressure and CO{sub 2} concentration are important in so far as the initial rapid reaction rate is concerned, but are relatively unimportant in terms of sorbent capacity and durability. Indirect evidence for the simultaneous occurrence of the shift reaction and CO{sub 2}-removal reaction creates the possibility of a direct one-step process for the production of hydrogen from coal-derived gas.

  11. Zinc titanate sorbents

    DOEpatents

    Gupta, Raghubir P.; Gangwal, Santosh K.; Jain, Suresh C.

    1998-01-01

    The present invention provides a zinc titanate sorbent material useful in desulfurization applications. The zinc titanate material is in the form of generally spherical particles of substantially uniform chemical distribution. The sorbent material is capable of absorbing sulfur compounds from a gaseous feed in an amount of at least about 15 weight percent based on the weight of the sorbent. The sorbent material is prepared by a process including: (a) forming a zinc oxide/titanium dioxide dry blend, (b) preparing a substantially uniform aqueous slurry comprising the zinc oxide/titanium dioxide dry blend, organic binder, and at least about 1 weight percent inorganic binder based on the solids weight of the slurry, (c) spray drying the slurry to produce substantially spherical particles, and (d) calcining the particles at a temperature of between about 750.degree. C. to about 950.degree. C. The dry blend is formed by mixing between about 0.5 to about 2 parts zinc oxide having a median particle size of less than about 0.5 .mu., and about 1 part titanium dioxide having a median particle size of less than about 1 .mu.. The slurry contains substantially no free silica and may be prepared by the process including (1) preparing an aqueous solution of organic binder, (2) adding the dry blend to the aqueous solution of organic binder, and (3) adding the inorganic binder to the solution of organic binder, and blend. Additional reagents, such as a surfactant, may also be incorporated into the sorbent material. The present invention also provides a process for desulfurizing a gaseous stream. The process includes passing a gaseous stream through a reactor containing an attrition resistant zinc titanate sorbent material of the present invention.

  12. Zinc titanate sorbents

    DOEpatents

    Gupta, R.P.; Gangwal, S.K.; Jain, S.C.

    1998-02-03

    The present invention provides a zinc titanate sorbent material useful in desulfurization applications. The zinc titanate material is in the form of generally spherical particles of substantially uniform chemical distribution. The sorbent material is capable of absorbing sulfur compounds from a gaseous feed in an amount of at least about 15 weight percent based on the weight of the sorbent. The sorbent material is prepared by a process including: (a) forming a zinc oxide/titanium dioxide dry blend, (b) preparing a substantially uniform aqueous slurry comprising the zinc oxide/titanium dioxide dry blend, organic binder, and at least about 1 weight percent inorganic binder based on the solids weight of the slurry, (c) spray drying the slurry to produce substantially spherical particles, and (d) calcining the particles at a temperature of between about 750 to about 950 C. The dry blend is formed by mixing between about 0.5 to about 2 parts zinc oxide having a median particle size of less than about 0.5 microns, and about 1 part titanium dioxide having a median particle size of less than about 1 micron. The slurry contains substantially no free silica and may be prepared by the process including (1) preparing an aqueous solution of organic binder, (2) adding the dry blend to the aqueous solution of organic binder, and (3) adding the inorganic binder to the solution of organic binder, and blend. Additional reagents, such as a surfactant, may also be incorporated into the sorbent material. The present invention also provides a process for desulfurizing a gaseous stream. The process includes passing a gaseous stream through a reactor containing an attrition resistant zinc titanate sorbent material of the present invention.

  13. Confined zone dispersion flue gas desulfurization demonstration. Quarterly report No. 8, August 17, 1992--November 16, 1992

    SciTech Connect

    Not Available

    1993-09-27

    The CZD process involves injecting a finely atomized slurry of reactive lime into the flue gas duct work of a coal-fired utility boiler. The principle of the confined zone is to form a wet zone of slurry droplets in the middle of the duct confined in an envelope of hot gas between the wet zone and the duct walls. The lime slurry reacts with part of the SO{sub 2} in the gas, and the reaction products dry to form solid particles. A solids collector, typically an electrostatic precipitator (ESP) downstream from the point of injection, captures the reaction products along with the fly ash entrained in the flue gas. The goal of this demonstration is to prove the technical and economic feasibility of the CZD technology on a commercial scale. The process is expected to achieve 50% SO{sub 2} removal at lower capital and O&M costs than other systems. To achieve its objectives, the project is divided into the following three phases: Phase 1: Design and Permitting, Phase 2: Construction and Start-up, Phase 3: Operation and Disposition. Phase 1 activities were completed on January 31, 1991. Phase 2 activities were essentially concluded on July 31, 1991, and Phase 3a, Parametric Testing, was initiated on July 1, 1991. This Quarterly Technical Progress Report covers Phase 3b activities from August 17, 1992 through November 16, 1992.

  14. Confined zone dispersion flue gas desulfurization demonstration. Quarterly report No. 9, November 17, 1992--February 16, 1993

    SciTech Connect

    Not Available

    1993-10-01

    The CZD process involves injecting a finely atomized slurry of reactive lime into the flue gas duct work of a coal-fired utility boiler. The principle of the confined zone is to form a wet zone of slurry droplets in the middle of the duct confined in an envelope of hot gas between the wet zone and the duct walls. The lime slurry reacts with part of the SO{sub 2} in the gas, and the reaction products dry to form solid particles. A solids collector, typically on electrostatic precipitator (ESP) downstream from the point of injection, captures the reaction products along with the fly ash entrained in the flue gas. The waste product is composed of magnesium and calcium sulfite and sulfate, with some excess lime. This product mixed with fly ash is self-stabilizing because of the excess lime values, and thus tends to retain heavy metals in insoluble forms within the fly ash. The demonstration is being conducted at Penelec`s Seward Station, Unit No. 15. This boiler is a 147 MWe coal-fired unit, which utilizes Pennsylvania bituminous coal (approximately 1.2 to 2.5% sulfur). Progress is described for the ninth quarter.

  15. Confined zone dispersion flue gas desulfurization demonstration. Volume 1, Quarterly report No. 6, February 1, 1992--April 30, 1992

    SciTech Connect

    Not Available

    1993-01-15

    This is the sixth quarterly report for this project and it covers work performed on Phase 3a of the project from February 1, 1992 through April 30, 1992. Extension of the parametric test period through June 1992 provides an opportunity to regain most of the schedule slippage, but only if the modifications needed for continuous operation of the CZD system are installed concurrent with the extended test period. These modifications include automation of the lime preparation and transfer system, automatic injection control, and related instrumentation and controls as necessary to integrate the operation of the CZD system with Seward Station Boiler No. 15. Early installation of these modifications would permit testing, debugging and adjustment of the automatic control system during the parametric test period. Results of current testing indicate that considerable testing and adjustment will be required to optimize operation of the CZD system after it is automated for continuous operation. Therefore, we intend to incorporate in Phase 3a(parametric testing) the system modifications needed for continuous automatic operation that were originally included in Phase 3b. Phase 3b would then be limited only to the one-year continuous demonstration.

  16. Confined zone dispersion flue gas desulfurization demonstration. Volume 1, Quarterly report No. 5, November 1, 1991--January 31, 1992

    SciTech Connect

    Not Available

    1992-12-31

    This is the fifth quarterly report for this project. This project is divided into three phases. Phase 1, which has been completed, involved design, engineering, and procurement for the CZD system, duct and facility modifications, and supporting equipment. Phase 2, also completed, included equipment acquisition and installation, facility construction, startup, and operator training for parametric testing. Phase 3 broadly covers testing, operation and disposition, but only a portion of Phase 3 was included in Budget Period 1. That portion was concerned with parametric testing of the CZD system to establish the optimum conditions for an extended, one-year, continuous demonstration. As of December 31, 1991, the following goals have been achieved. (1) Nozzle Selection - A modified Spraying Systems Company (SSC) atomizing nozzle has been selected for the one-year continuous CZD demonstration. (2) SO{sub 2} and NO{sub x} Reduction - Preliminary confirmation of 50% SO{sub 2} reduction has been achieved, but the NO{sub x} reduction target cannot be confirmed at this time. (3) Lime Selection - Testing indicated an injection rate of 40 to 50 gallons per minute with a lime slurry concentration of 8 to 10% to achieve 50% SO{sub 2} reduction. There has been no selection of the lime to be used in the one year demonstration. (4) ESP Optimization - Tests conducted to date have shown that lime injection has a very beneficial effect on ESP performance, and little adjustment may be necessary. (5) SO{sub 2} Removal Costs - Testing has not revealed any significant departure from the bases on which Bechtel`s original cost estimates (capital and operating) were prepared. Therefore, SO{sub 2} removal costs are still expected to be in the range of $300/ton or less.

  17. Molten iron oxysulfide as a superior sulfur sorbent. Third quarter technical progress report, March 1, 1990--June 1, 1990

    SciTech Connect

    Hepworth, M.T.

    1990-12-31

    Slagging combustors with injected lime or limestone are being considered as replacements for conventional coal burners. They have advantages in that they can be staged to reduce NO{sub x} and SO{sub x} emissions. Iron oxide, as an alternative to lime or limestone may be effective not only as a desulfurizing agent, but, under the right conditions of oxygen potential, it can act as a flux to produce a glassy slag. This glassy slag should be dense and environmentally inert. In this reporting period, the thermodynamic conditions are determined for the operation of the first stage of a combustor which would have as its feed six types of coals. The calculations are made for the four phase equilibrium: FeO(wustite)/Fe/Liquid/Gas over the temperature range 950{degrees} to 1300{degrees}C. The minimum dosage of iron oxide required at equilibrium an the calculated maximum percent sulfur removal are reported. Also given are the expected pounds of S0{sub 2} per million Btu of heat evolution calculated for complete combustion. These preliminary results indicate in the Fe-O-S system that higher temperatures give better results approaching 96 percent sulfur removal from a coal containing (on a dry basis) 3.29% by weight sulfur. In the prior reporting period, a comparison is made between iron oxide and lime as a desulfurizing agent. With lime, the thermodynamic conditions were chosen: a set of conditions where the compound calcium sulfide is the product and a set of conditions where calcium sulfate is the product. The temperature limits of the sulfate forming and sulfide forming reactions were defined.

  18. Hot Gas Desulfurization Using Transport Reactors

    SciTech Connect

    Moorehead, E.L.

    1996-12-31

    Sierra Pacific Power Company is building a 100 MW, IGCC power plant based on KRW fluid bed gasifier technology that utilizes transport reactors for hot gas desulfurization and sorbent regeneration. Use of a transport absorber avoids the need for pre-filtration of dust-laden gasifier effluent, while a transport regenerator allows for the use of 100% air without the need for heat exchange equipment. Selection of transport reactors for hot gas desulfurization using a proprietary sorbent, based on testing performed in a transport reactor test unit (TRTU) at the M. W. Kellogg Technology Development Center and in a fixed bed reactor at Morgantown Energy Technology Center (METC), is outlined. The results obtained in these two test facilities and reasons for selecting transport reactors for the IGCC power plant in preference to either fixed bed or fluidized bed reactors are discussed. This paper reviews the evolution of the hot gas desulfurization system designs and includes selected results on H{sub 2}S absorption and regeneration of sulfided sorbent over several absorption/regeneration cycles conducted in the TRTU and the METC fixed bed reactor. The original design for the Sierra Pacific Project was based on fixed bed reactors with zinc ferrite as the sorbent. Owing to the high steam requirements of this sorbent, zinc titanate was selected and tested in a fixed bed reactor and was found unacceptable due to loss of strength on cyclic absorption/regeneration operation. Another sorbent evaluated was Z-Sorb{reg_sign}, a proprietary sorbent developed by Phillips Petroleum Company, was found to have excellent sulfur capacity, structural strength and regenerability. Steam was found unsuitable as fixed bed regenerator diluent, this results in a requirement for a large amount of inert gas, whereas a transport regenerator requires no diluent. The final Sierra design features transport reactors for both desulfurization and regeneration steps using neat air. 3 refs., 3 figs., 2 tabs.

  19. Hot gas desulfurization with oxides of zinc, iron, and vanadium

    SciTech Connect

    Akyurtlu, J.F.; Akyurtlu, A.

    1992-08-01

    The objective of this study is to develop an improved sorbent which can reduce H{sub 2}S levels up to 1 ppmv or less, which can stabilize zinc, and produce economically recoverable amounts of elemental sulfur during regeneration. For this purpose, the desulfurization performance of sorbents prepared by the addition of various amounts of V{sub 2}O{sub 5} to the zinc ferrite sorbent is investigated.

  20. Molten iron oxysulfide as a superior sulfur sorbent. Third quarter technical progress report, June 1--August 31, 1990

    SciTech Connect

    Hepworth, M.T.

    1990-12-31

    Slagging combustors with injected lime or limestone are being considered as replacements for conventional coal burners. They have advantages in that they can be staged to reduce NO{sub x} and SO{sub x} emissions. Iron oxide, as an alternative to lime or limestone may be effective not only as a desulfurizing agent, but under the right conditions of oxygen potential and after combination with sulfur, the reaction products of coal gases with iron oxide can act as a flux to produce a fluid phase. The thermodynamic conditions for determining the most effective operating conditions of the first stage of a combustor are calculated for several Illinois coals. These conditions include contact of the gas with the phase combinations: CaO/CaSO{sub 4}, CaO/CaS, and Fe/FeO/liquid for the temperature range 950{degree} to 1300{degree}C. In the latter system, the minimum dosage of iron required at equilibrium and the calculated maximum percent sulfur removal are reported. Also given are the expected pounds of SO{sub 2} per million Btu of heat evolution calculated for complete combustion. The calculations indicate that for the Fe-O-S system, higher temperatures give better results approaching 96 percent sulfur removal from a coal containing 4.2% sulfur. For this example, the stack gas emerging from the second stage of combustion under stoichiometric conditions would contain 0.36 pounds of SO{sub 2} per million BTU`s of heat generated. The temperature limits of the sulfate and sulfide forming reactions are defined.

  1. Adsorption and Ultrasound-Assisted Sorbent Regeneration

    SciTech Connect

    Yuhe Wang; Liping Ma; Ralph T. Yang

    2006-09-30

    This work was conducted for the department of Energy. In this work, we developed a class of new sorbents that were highly sulfur selective and had high sulfur capacities. The study consisted of two sections. Development of the new sorbents is described in Section 1, and Section was a fundamental study, conducted for a better understanding for desulfurization of jet fuels. More details of the results are given blow separately for the two sections.

  2. Enhancing the use of coals by Gas Reburning: Sorbent injection. [Quarterly report], July 28--October 1, 1993

    SciTech Connect

    1995-02-01

    Energy and Environmental Research Corporation (EER) has completed demonstrations of Gas Reburning-Sorbent Injection (GR-SI) at two field sites. The discussions which follow pertain to measurements taken from the demonstration at City Water, Light and Power`s (CWLP) Lakeside Station Unit 7 in Springfield, Illinois. Environmental monitoring was conducted for two purposes, to satisfy the requirements of operating permits granted by the Illinois Environmental Protection Agency (IEPA) and to verify environmental acceptability of the GR-SI process. The GR-SI demonstration program at Lakeside Unit 7 was performed in three phases. Phase I -- Design and Permitting, entailed characterization of the host boiler, then finalization of process and engineering, design of the GR-SI system. Phase I was initiated in June 1987 and completed in March 1989. Phase II -- Construction and Startup, was initiated upon completion of design tasks and was completed in February 1993. Phase III -- Operation, Data Collection, Reporting and Disposition, was conducted from July 1993 to June 1994. In Phase III, the GR-SI system performance was evaluated initially through optimization tests, which are short-term tests in which specific operating parameters are varied to determine their impact on emissions and boiler performance. The optimization testing included GR only tests, SI only tests, and GR-SI tests. Results from these tests, carried out from July 28 to October 1, 1993, are presented in this report. Following Optimization testing, long-term GR-SI operation was initiated to demonstrate the combined technology over an extended period with the unit under dispatch load control. Long-term GR-SI testing was conducted from October 4, 1993 to June 3, 1994. The long-term environmental monitoring data are presented in a separate report.

  3. Kinetics of mn-based sorbents for hot gas desulfurization: Task 2 - exploratory experimental studies. Quarterly report, March 15, 1996--June 15, 1996

    SciTech Connect

    Hepworth, M.T.; Berns, J.

    1996-06-12

    The objective of this project is to develop a pellet formulation which is capable of achieving low sulfur partial pressures and a high capacity for sulfur, loaded from a hot fuel gas and which is readily regenerable. Furthermore the pellet must be strong for potential use in a fluidized bed and regenerable over many cycles of loading and regeneration. Regeneration should be in air or oxygen-depleted air to produce a high-concentration sulfur dioxide. Fixed-bed tests were conducted with several formulations of manganese sesquioxide and titania, and alumina They were subject to a simplified fuel gas of the oxygen-blown Shell type spiked with a 30,000ppmv concentration of H{sub 2}S. Pellet crush strengths for 4 and 2mm diameter pellets was typically 12 lbs per pellet and 4 lbs per pellet, respectively. For the most favorable of the formulations tested and under the criteria of break-through at less than 100ppmv H2S and loading temperatures of 500{degrees}C and an empty-bed space velocity of 4,000 per hour, breakthrough occurred an effective loading of sulfur of 27 to 29% over 5 loading and regeneration cycles. At 90% of this saturation condition, the observed level of H{sub 2}S was below 10ppmv. For regeneration, a temperature of 900{degrees}C is required to dissociate the sulfide into sulfur dioxide using air at atmospheric pressure. The mean sulfur dioxide concentration which is achieved during regeneration is 8% with empty-bed space velocities of 700/hr. TGA tests on individual pellets indicate that bentonite is not desirable as a bonding material and that Mn/Ti ratios higher than 7:1 produce relatively non-porous pellets. Whereas the reactivity is rapid below 12% conversion, the kinetics of conversion decreases significantly above this level. This observation may be the result of plugging of the pellet pores with sulfided product creating inaccessible pore volumes or alternately an increase m diffusional resistance by formation of MnS.

  4. Low temperature SO{sub 2} removal with solid sorbents in a circulating fluidized bed absorber. Final report

    SciTech Connect

    Lee, S.K.; Keener, T.C.

    1994-10-10

    A novel flue gas desulfurization technology has been developed at the University of Cincinnati incorporating a circulating fluidized bed absorber (CFBA) reactor with dry sorbent. The main features of CFBA are high sorbent/gas mixing ratios, excellent heat and mass transfer characteristics, and the ability to recycle partially utilized sorbent. Subsequently, higher SO{sub 2} removal efficiencies with higher overall sorbent utilization can be realized compared with other dry sorbent injection scrubber systems.

  5. LIFAC sorbent injection desulfurization demonstration project

    SciTech Connect

    Not Available

    1991-01-01

    LIFAC combines upper-furnace limestone injection followed by post-furnace humidification in an activation reactor located between the air preheater and the ESP. The process produces a dry and stable waste product that is partially removed from the bottom of the activation reactor and partially removed at the ESP.

  6. Aerogel sorbents

    DOEpatents

    Begag, Redouane; Rhine, Wendell E; Dong, Wenting

    2016-04-05

    The current invention describes methods and compositions of various sorbents based on aerogels of various silanes and their use as sorbent for carbon dioxide. Methods further provide for optimizing the compositions to increase the stability of the sorbents for prolonged use as carbon dioxide capture matrices.

  7. Effect of operating parameters and reactor structure on moderate temperature dry desulfurization

    SciTech Connect

    Jie Zhang; Changfu You; Haiying Qi; Bo Hou; Changhe Chen; Xuchang Xu

    2006-07-01

    A moderate temperature dry desulfurization process at 600-800 C was studied in a pilot-scale circulating fluidized bed flue gas desulfurization (CFB-FGD) experimental facility. The desulfurization efficiency was investigated for various operating parameters. Structural improvements in key parts of the CFB-FGD system, i.e., the cyclone separator and the distributor, were made to improve the desulfurization efficiency and flow resistance. The experimental results show that the desulfurization efficiency increased rapidly with increasing temperature above 600 C due to enhanced gas diffusion and the shift of the equilibrium for the carbonate reaction. The sorbent sulfated gradually after quick carbonation of the sorbent with a long particle residence time necessary to realize a high desulfurization ratio. A reduced solids concentration in the bed reduced the particle residence time and the desulfurization efficiency. A single-stage cyclone separator produced no improvement in the desulfurization efficiency compared with a two-stage cyclone separator. Compared with a wind cap distributor, a large hole distributor reduced the flow resistance which reduced the desulfurization efficiency due to the reduced bed pressure drop and worsened bed fluidization. The desulfurization efficiency can be improved by increasing the collection efficiency of fine particles to prolong their residence time and by improving the solids concentration distribution to increase the gas-solid contact surface area. 16 refs., 9 figs.

  8. Effect of operating parameters and reactor structure on moderate temperature dry desulfurization.

    PubMed

    Zhang, Jie; You, Changfu; Qi, Haiying; Hou, Bo; Chen, Changhe; Xu, Xuchang

    2006-07-01

    A moderate temperature dry desulfurization process at 600-800 degrees C was studied in a pilot-scale circulating fluidized bed flue gas desulfurization (CFB-FGD) experimental facility. The desulfurization efficiency was investigated for various operating parameters, such as bed temperature, CO2 concentration, and solids concentration. In addition, structural improvements in key parts of the CFB-FGD system, i.e., the cyclone separator and the distributor, were made to improve the desulfurization efficiency and flow resistance. The experimental results show that the desulfurization efficiency increased rapidly with increasing temperature above 600 degrees C due to enhanced gas diffusion and the shift of the equilibrium for the carbonate reaction. The sorbent sulfated gradually after quick carbonation of the sorbent with a long particle residence time necessary to realize a high desulfurization ratio. A reduced solids concentration in the bed reduced the particle residence time and the desulfurization efficiency. A single-stage cyclone separator produced no improvement in the desulfurization efficiency compared with a two-stage cyclone separator. Compared with a wind cap distributor, a large hole distributor reduced the flow resistance which reduced the desulfurization efficiency due to the reduced bed pressure drop and worsened bed fluidization. The desulfurization efficiency can be improved by increasing the collection efficiency of fine particles to prolong their residence time and by improving the solids concentration distribution to increase the gas-solid contact surface area.

  9. Investigation and demonstration of dry carbon-based sorbent injection for mercury control. Quarterly technical report, July 1, 1996--September 31, 1996

    SciTech Connect

    Hunt, T.; Sjostrom, S.; Smith, J.

    1996-11-06

    The overall objective of this two phase program is to investigate the use of dry carbon-based sorbents for mercury control. This information is important to the utility industry in anticipation of pending regulations. During Phase I, a bench-scale field test device that can be configured as an electrostatic precipitator, a pulse-jet baghouse, or a reverse-gas baghouse has been designed, built and integrated with an existing pilot-scale facility at PSCo`s Comanche Station. Up to three candidate sorbents will be injected into the flue gas stream upstream of the test device to and mercury concentration measurements will be made to determine the mercury removal efficiency for each sorbent. During the Phase II effort, component integration for the most promising dry sorbent technology shall be tested at the 5000 acfm pilot-scale.

  10. Investigation and demonstration of dry carbon-based sorbent injection for mercury control. Quarterly report, November 1, 1995--December 31, 1995

    SciTech Connect

    Hunt, T.; Sjostrom, S.

    1996-02-05

    The overall objective to this two phase program is to investigate dry carbon-based sorbents for mercury control. During Phase I, a bench-scale field test device that can simulate an electrostatic precipitator, a pulse-jet baghouse, or a reverse-gas baghouse will be designed and integrated with an existing pilot-scale facility at Public Service Company of Colorado`s (PSCo`s) Comanche station. Various sorbents will then be injected to determine the mercury removal efficiency for each. During Phase II effort, component integration of the most promising technologies shall be tested at the 5000 acfm pilot-scale. The primary task currently underway is the facility design. The design is expected to be finished in January, 1996. The facility, regardless of the particulate control module configuration, will be fitted with supply line injection port, through which mercury sorbents and SO{sub 2} control sorbents can be added to the flue gas stream.

  11. CURRENT STATUS OF ADVACATE PROCESS FOR FLUE GAS DESULFURIZATION

    EPA Science Inventory

    The following report discusses current bench- and pilot-plant advances in preparation of ADVAnced siliCATE (ADVACATE) calcium silicate sorbentsfor flue gas desulfurization. It also discusses current bench- and pilot-plant advances in sorbent preparation. Fly ash was ground in a l...

  12. Sorbent suppliers

    SciTech Connect

    Vedder, M.

    1994-03-01

    Sorbents are used to absorb or contain spilled and leaking chemicals, oils, lubricants and other process fluids. They are commonly used around the base of machinery in industrial applications, and in remediating oil spills on land and water. Sorbents are made from biodegradable, inorganic or synthetic materials. Organic materials include corn cobs, wood pulp, paper fiber and cotton. Inorganic materials include clay, perlite, expanded silicates and expanded mica. Synthetic sorbents are made from petroleum- or plastic-based materials such as polyurethane, polyethylene or polypropylene. Sorbents are available in a variety of forms, including pads, rolls, booms, pillows and loose particulate.

  13. Advanced low-temperature sorbents

    SciTech Connect

    Ayala, R.E.; Venkataramani, V.S.; Abbasian, J.; Hill, A.H.

    1995-12-01

    A number of promising technologies are currently being optimized for coal-based power generation, including the Integrated-Gasification Combined Cycle (IGCC) system. If IGCC is to be used successfully for power generation, an economic and efficient way must be found to remove the contaminants, particularly sulfur species, found in coal gas. Except for the hot gas desulfurization system, all major components of IGCC are commercially available or have been shown to meet system requirements. Over the last two decades, the U.S. Department of Energy/Morgantown Energy Technology Center (DOE/METC) has sponsored development of various configurations of high-temperature desulfurization systems including fixed-bed, moving-bed, transport-bed, and fluidized-bed systems. Because of their mode of operation and requirements for sorbent manufacturing, the fixed-bed systems can generally use the same materials as moving-bed configurations, i.e., pelletized or extruded sorbents, while fluidized-bed (circulating or bubbling configurations) and transport reactor configurations use materials generally described as agglomerated or granulated.The objective of this program is to remove hydrogen sulfides from coal gas using sorbent materials.

  14. Investigation of combined SO{sub 2}/NO{sub x} removal by ceria sorbents. Quarterly technical progress report, October 1993--December 1993

    SciTech Connect

    Akyurtlu, A.

    1994-06-01

    Simultaneous removal of SO{sub 2} and NO{sub x} using a regenerable solid sorbent will constitute an important improvement over the use of separate processes for the removal of these two pollutants from stack gases and possibly eliminate several shortcomings of the individual SO{sub 2} and NO{sub x} removal operations. This process will allow simple and reliable cleanup of large volumes of stack gases as a competitive cost; produce a concentrated stream of SO{sub 2} which can easily be converted into valuable by-products; be compatible with existing power generation plants; and essentially eliminate the waste materials generated in some other sulfur removal processes. Department of Energy`s Pittsburgh Energy Technology Center (PETC) and UOP/Shell have developed processes which both employ copper oxide-based sorbents in different reactor configurations, namely, former uses a regenerative fluidized bed while the latter employs a cyclic fixed bed contactor. More recent studies at PETC considered cerium oxide as an alternate sorbent to CuO. Ceria improves the resistance of the alumina support to thermal sintering and produces a regeneration off-gas stream that can be easily converted to elemental sulfur. It has a potentially higher sulfur capture capacity than copper. The objective of this research is to determine the effects of ammonia on the sulfation of the sorbent; to determine the effects of fly ash on the sulfation and regeneration of the sorbent; to obtain a rate expression for the regeneration of alumina-supported CeO{sub 2} sorbents; to model reactor configurations for a commercial scale combined CeO{sub 2}/Al{sub 2}O{sub 3} sorbent; and to study alternative designs, effects of design variables on the performance of the facility, and the economics of the process using the developed model.

  15. Investigation of combined SO{sub 2}/NO{sub x} removal by Ceria Sorbents. Quarterly technical progress report, January 1, 1994--March 31, 1994

    SciTech Connect

    Akyurtlu, A.; Akyurtlu, J.F.

    1994-07-01

    Simultaneous removal of SO{sub 2} and NO{sub x} using a regenerable solid sorbent will constitute an important improvement over the use of separate processes for the removal of these two pollutants from stack gases and possibly eliminate several shortcomings of the individual SO{sub 2} and NO{sub x} removal operations. This process will allow simple and reliable cleanup of large volumes of stack gases at a competitive cost; produce a concentrated stream of SO{sub 2} which an easily be converted into valuable by-products; be compatible with existing power generation plants; and essentially eliminate the waste materials generated in some other sulfur removal processes. Department of Energy`s Pittsburgh Energy Technology Center (PETC) and UOP/Shell have developed processes which both employ copper oxide-based sorbents in different reactor configurations, namely, former uses a regenerative fluidized bed while the latter employs a cyclic fixed bed contactor. More recent studies at PETC considered cerium oxide as an alternate sorbent to CuO{sup (1,2)}. Ceria improves the resistance of the alumina support to thermal sintering and produces a regeneration off-gas stream that can be easily converted to elemental sulfur. It has potentially higher sulfur capture capacity than copper. The objective of this research is to determine the effects of ammonia on the sulfation of the sorbent; to determine the effects of fly ash on the sulfation and regeneration of the sorbent; to obtain a rate expression for the regeneration of alumina-supported CeO{sub 2} sorbents; to model reactor configurations for a commercial scale combined CeO{sub 2}/Al{sub 2}O{sub 3} sorbent; and to study alternative designs, effects of design variables on the performance of the facility, and the economics of the process using the developed model.

  16. ADVANCED SULFUR CONTROL CONCEPTS FOR HOT-GAS DESULFURIZATION TECHNOLOGY

    SciTech Connect

    A. LOPEZ ORTIZ; D.P. HARRISON; F.R. GROVES; J.D. WHITE; S. ZHANG; W.-N. HUANG; Y. ZENG

    1998-10-31

    This research project examined the feasibility of a second generation high-temperature coal gas desulfurization process in which elemental sulfur is produced directly during the sorbent regeneration phase. Two concepts were evaluated experimentally. In the first, FeS was regenerated in a H2O-O2 mixture. Large fractions of the sulfur were liberated in elemental form when the H2O-O2 ratio was large. However, the mole percent of elemental sulfur in the product was always quite small (<<1%) and a process based on this concept was judged to be impractical because of the low temperature and high energy requirements associated with condensing the sulfur. The second concept involved desulfurization using CeO2 and regeneration of the sulfided sorbent, Ce2O2S, using SO2 to produce elemental sulfur directly. No significant side reactions were observed and the reaction was found to be quite rapid over the temperature range of 500°C to 700°C. Elemental sulfur concentrations (as S2) as large as 20 mol% were produced. Limitations associated with the cerium sorbent process are concentrated in the desulfurization phase. High temperature and highly reducing coal gas such as produced in the Shell gasification process are required if high sulfur removal efficiencies are to be achieved. For example, the equilibrium H2S concentration at 800°C from a Shell gas in contact with CeO2 is about 300 ppmv, well above the allowable IGCC specification. In this case, a two-stage desulfurization process using CeO2 for bulk H2S removal following by a zinc sorbent polishing step would be required. Under appropriate conditions, however, CeO2 can be reduced to non-stoichiometric CeOn (n<2) which has significantly greater affinity for H2S. Pre-breakthrough H2S concentrations in the range of 1 ppmv to 5 ppmv were measured in sulfidation tests using CeOn at 700°C in highly reducing gases, as measured by equilibrium O2 concentration, comparable to the Shell gas. Good sorbent durability was indicated in

  17. High-volume, high-value usage of Flue Gas Desulfurization (FGD) by-products in underground mines Phase 1: Laboratory investigations. Quarterly report, July 1994--September 1994

    SciTech Connect

    1994-12-01

    During the quarter a second series of samples were collected and partially characterized chemically and mineralogically. The samples were collected at the disposal site operated by Freeman United Coal Co. The second collection was necessary because of deterioration due to hydration of the original samples. A study of the hydration characteristics was completed during the quarter. Important reactions included the immediate formation of ettringite and portlandite. The hydration and transformation was found to be a slow process. A second phase of gypsum formation from ettringite deterioration was identified. The slow hydration of anhydrite with its resultant swell is a potential problem which will be addressed further. Geotechnical characterization, during the quarter included completion of the preliminary characterization, analysis of the findings, experimentation with sample preparation for the final characterization/mix design, and design of the final experimental program. The analysis of the coals collected during the core drilling and hydrologic planning were completed. Also during the quarter a meeting was held with representatives of the shotcrete industry to discuss transport systems for emplacement. The pros and cons of pneumatic and hydraulic systems were discussed and plans formulated for further investigations.

  18. Development of novel copper-based sorbents for hot-gas cleanup. [Quarterly] technical report, December 1, 1993--February 28, 1994

    SciTech Connect

    Abbasian, J.; Hill, A.H.; Flytzani-Stephanopoulos, M.; Li, Zhijiang

    1994-06-01

    The objective of this investigation is to evaluate two novel copper-based sorbents, namely copper-chromium and copper-cerium, for their effectiveness in removing hydrogen sulfide from fuel gas in the temperature range of 650{degree} to 850{degree}. Such high temperatures will be required for the new generation of gas turbines (inlet >750{degree}C) in Integrated Gasification Combined Cycle (IGCC) systems. The effect of pre-reduction with H{sub 2}, in the presence of H{sub 2}O on the performance of the sorbents in cyclic sulfidation/regeneration, was studied in a thermogravimetric analyzer (TGA) and in a fixed-bed reactor at 750{degree}C. The results of the TGA tests indicate that pre-reduction of the sorbents is very fast in either 10% or 30% H{sub 2}. Without sorbent pre-reduction, sulfidation consists of two-stages, a reduction-dominating and a sulfidation-dominating stage. Sulfidation apparently takes place before reduction is complete. During regeneration some copper/cerium sulfates may have formed and Cu{sub 2}O may have formed in addition to CuO. The fixed-bed reactor tests show that at 750{degree}C: (1) prereducing the CuO-Cr{sub 2}O{sub 3} with H{sub 2} does not effect the reactivity of the sorbent towards H{sub 2}S at either the high or low H{sub 2} feed gas concentrations and (2) when 30% H{sub 2} was used during sulfidation of either sorbent, the first H{sub 2}S breakthrough occurs earlier than when 10% H{sub 2} was used.

  19. High-volume, high-value usage of flue gas desulfurization (FGD) by-products in underground mines - Phase I: Laboratory investigations. Quarterly report, October 1993--December 1993

    SciTech Connect

    Not Available

    1994-03-01

    This project proposes to use pneumatically or hydraulically emplaced dry-flue gas desulfurization (FGD) by-products to backfill the adits left by highwall mining. Backfilling highwall mine adits with dry-FGD materials is technically attractive. The use of an active highwall mine would allow the dry-FGD material to be brought in using the same transportation network used to move the coal out, eliminating the need to recreated the transportation infrastructure, thereby saving costs. Activities during the period included the negotiations leading to the final cooperative agreement for the project and the implementation of the necessary instruments at the University of Kentucky to administer the project. Early in the negotiations, a final agreement on a task structure was reached and a milestone plan was filed. A review was initiated of the original laboratory plan as presented in the proposal, and tentative modifications were developed. Selection of a mine site was made early; the Pleasant Valley mine in Greenup County was chosen. Several visits were made to the mine site to begin work on the hydrologic monitoring plan. The investigation of the types of permits needed to conduct the project was initiated. Considerations concerning the acceptance and implementation of technologies led to the choice of circulating fluidized bed ash as the primary material for the study. Finally, the membership of a Technical Advisory Committee for the study was assembled.

  20. Cross-flow, filter-sorbent catalyst for particulate, SO{sub 2} and NO{sub x} control. First quarterly technical progress report, 1990

    SciTech Connect

    Not Available

    1990-03-01

    This synopsis describes a new concept for integrated pollutant control: a cross-flow filter comprised of layered, gas permeable membranes that act as a particulate filter, an SO{sub 2} sorbent, and a NO{sub x} reduction catalyst.

  1. Molecular biological enhancement of coal desulfurization: Cloning and expression of the sulfoxide/sulfone/sulfonate/sulfate genes in Pseudomonads and Thiobacillae. [Rhodococcus erythropolis, Thiobacillus acidophilus, Thiobacillus novellus

    SciTech Connect

    Krawiec, S.

    1992-01-01

    Research continues on desulfurization of coal using microorganisms. Topics reported on this quarter include: desulfurization with N1-36 (presumptively identified as Rhodochrous erythropolis), pulsed-field gel electrophoresis of chromosomal DNA's of Thiobacillus spp., and fresh isolates with the presumptive capacity to desulfurize dibenzothiophenes.

  2. High-volume, high-value usage of Flue Gas Desulfurization (FGD) by-products in underground mines. Phase 1 -- Laboratory Investigations. Quarterly report, January 1995--March 1995

    SciTech Connect

    1995-06-01

    The study of the kinetics of the mineral transformations which take place after the FGD materials are hydrated was continued this quarter (Task 2, Subtask 2.2). Based on X-ray diffraction data, the anhydrite was found to have essentially disappeared by the fifth day of the study, while gypsum was found to maximize in the first 14 days of the study. The relative abundance of ettringite increased throughout the period of observation (40 days). Ettringite was found to nucleate primarily on or near fly ash particles, while gypsum was found to be more mobile, readily filling in cracks and fractures. A second kinetic study was initiated during the period with an experimental setup which is similar to the current effort. The focus of this study will be to determine the effect of moisture conditions on the rate and types of mineralogical reactions which occur. Column leaching studies (Task 2, Subtask 2.4) on the ADM material were initiated during the quarter. Two columns were packed with fly ash and one with bottom ash. One of the columns was blanketed with CO{sub 2} (2.5%) to model the effects of soil gas on the leachate. The samples are being moisturized to model field conditions. Leachate analysis will be available during the next quarter. Work on the field site (Task 6) to establish background data for the demonstration continued. The proposed demonstration site at the Pleasant Valley mine was found to be displaying the effects of severe weathering. An alternate mine site will be explored.

  3. High Volume--High Volume Usage of Flue Gas Desulfurization (FGD) By-Products in Underground Mines. Quarterly report, July 1-September 31, 1996

    SciTech Connect

    1997-12-31

    The focus of activity for this quarter was the final selection and preparation of a mine site for the grout emplacement field demonstration. The site chosen is located in Floyd County, Kentucky and is owned by the Sunny Ridge Mining Company. Specifically, a northeast-trending highwall was selected that contains numerous auger holes of 31 inch diameter and varying depth. The coal has been deep- mined beyond the auger holes thus limiting their length. Access to the site is good, and the overlying strata are relatively un- weathered and competent. Preparation of the site involved culling a road to the highwall, followed by uncovering the auger holes which had previously been partially filled and graded with rock. The auger holes were then extensively characterized in the context of overall dimensions, condition, and extent of communication between holes. For this portion of the work, several types of apparatus were obtained, and constructed. Selection of a grout emplacement method was also completed. It was decided that concrete trucks will transport the dry FBC flyash to the site whereupon a specified amount of water will be added. This grout will then be transferred to a concrete pumping truck that will be used to inject the material into the auger holes. In this quarter, the arrangements necessary to complete the emplacement have been made.

  4. THE BIOCATALYTIC DESULFURIZATION PROJECT

    SciTech Connect

    Steven E. Bonde; David Nunn

    2003-01-01

    During the first quarter of the Biological Desulfurization project several activities were pursued. A project kickoff meeting was held at the Diversa facility in San Diego, CA. Activities that were in process before the meeting and begun afterwards by Diversa Corporation and Petro Star Inc. include: Technology transfer in the form of information generated by Enchira to Diversa, the purchase and installation of equipment by Diversa, development of synthetic methods and preparation of organo-sulfur substrates for use in determining enzyme activities, production of extract via Petro Star's CED process, detailed analysis of Petro Star Inc. diesel and CED extract, and several activities in molecular biology. Diversa Corporation, in the area of molecular biology, engaged in several activities in support of the task list of the contract. These included: construction of a genomic library; development and utilization of a sequence-based gene discovery effort; a parallel discovery approach based on functional expression of enzymes with the ability to oxidize organosulfur compounds. Biodesulfurization genes have already been identified and are being sequenced and subcloned for expression in heterologous biological hosts. Diversa has evaluated and adapted assays developed by Enchira used to assess the activities of DBT and DBTO{sub 2} monooxygenases. Finally, Diversa personnel have developed two novel selection/screen strategies for the improvement of biocatalyst strains by directed evolution.

  5. ADVANCED SORBENT DEVELOPMENT PROGRAM DEVELOPMENT OF SORBENTS FOR MOVING-BED AND FLUIDIZED-BED APPLICATIONS

    SciTech Connect

    R.E Ayala; V.S. Venkataramani; Javad Abbasian; Rachid B. Slimane; Brett E. Williams; Minoo K. Zarnegar; James R. Wangerow; Andy H. Hill

    2000-03-31

    The integrated gasification combined cycle (IGCC) power system using high-temperature coal gas cleanup is one of the most promising advanced technologies for the production of electric power from coal in an environmentally acceptable manner. Unlike conventional low-temperature cleanup systems that require costly heat exchangers, high-temperature coal gas cleanup systems can be operated near 482-538 C (900-1000 F) or higher, conditions that are a closer match with the gasifier and turbine components in the IGCC system, thus resulting is a more efficient overall system. GE is developing a moving-bed, high-temperature desulfurization system for the IGCC power cycle in which zinc-based regenerable sorbents are currently being used as desulfurization sorbents. Zinc titanate and other proprietary zinc-based oxides are being considered as sorbents for use in the Clean Coal Technology Demonstration Program at Tampa Electric Co.'s (TECo) Polk Power Station. Under cold startup conditions at TECo, desulfurization and regeneration may be carried out at temperatures as low as 343 C (650 F), hence a versatile sorbent is desirable to perform over this wide temperature range. A key to success in the development of high-temperature desulfurization systems is the matching of sorbent properties for the selected process operating conditions, namely, sustainable desulfurization kinetics, high sulfur capacity, and mechanical durability over multiple cycles. Additionally, the sulfur species produced during regeneration of the sorbent must be in a form compatible with sulfur recovery systems, such as sulfuric acid or elemental sulfur processes. The overall objective of this program is to develop regenerable sorbents for hydrogen sulfide removal from coal-derived fuel gases in the temperature range 343-538 C (650-1000 F). Two categories of reactor configurations are being considered: moving-bed reactors and fluidized-bed (bubbling and circulating) reactors. In addition, a cost assessment

  6. ADVANCED SORBENT DEVELOPMENT PROGRAM; DEVELOPMENT OF SORBENTS FOR MOVING-BED AND FLUIDIZED-BED APPLICATIONS

    SciTech Connect

    AYALA, R E; VENKATARAMANI, V S

    1998-09-30

    The integrated gasification combined cycle (IGCC) power system using high-temperature coal gas cleanup is one of the most promising advanced technologies for the production of electric power from coal in an environmentally acceptable manner. Unlike conventional low-temperature cleanup systems that require costly heat exchangers, high-temperature coal gas cleanup systems can be operated near 482-538 °C (900-1000 °F) or higher, conditions that are a closer match with the gasifier and turbine components in the IGCC system, thus resulting is a more efficient overall system. GE is developing a moving-bed, high-temperature desulfurization system for the IGCC power cycle in which zinc-based regenerable sorbents are currently being used as desulfurization sorbents. Zinc titanate and other proprietary zinc-based oxides are being considered as sorbents for use in the Clean Coal Technology Demonstration Program at Tampa Electric Co.'s (TECo) Polk Power Station. Under cold startup conditions at TECo, desulfurization and regeneration may be carried out at temperatures as low as 343 °C (650 °F), hence a versatile sorbent is desirable to perform over this wide temperature range. A key to success in the development of high-temperature desulfurization systems is the matching of sorbent properties for the selected process operating conditions, namely, sustainable desulfurization kinetics, high sulfur capacity, and mechanical durability over multiple cycles. Additionally, the sulfur species produced during regeneration of the sorbent must be in a form compatible with sulfur recovery systems, such as sulfuric acid or elemental sulfur processes. The overall objective of this program is to develop regenerable sorbents for hydrogen sulfide removal from coal-derived fuel gases in the temperature range 343-538 °C (650-1000 °F). Two categories of reactor configurations are being considered: moving-bed reactors and fluidized-bed (bubbling and circulating) reactors. In addition, a cost

  7. Flue gas desulfurization wastewater treatment primer

    SciTech Connect

    Higgins, T.E.; Sandy, A.T.; Givens, S.W.

    2009-03-15

    Purge water from a typical wet flue gas desulfurization system contains myriad chemical constituents and heavy metals whose mixture is determined by the fuel source and combustion products as well as the stack gas treatment process. A well-designed water treatment system can tolerate upstream fuel and sorbent arranged in just the right order to produce wastewater acceptable for discharge. This article presents state-of-the-art technologies for treating the waste water that is generated by wet FGD systems. 11 figs., 3 tabs.

  8. High Volume - High Value Usage of Flue Dry Gas Desulfurization (FGD) By-Products in Underground Mines: Quarterly report, January 1-March 31, 1997

    SciTech Connect

    1997-12-31

    Activities during the quarter focused on two areas: monitoring of grout strength from the field demonstration (Subtask 1.4) and construction of laboratory lysimeters to examine the leaching characteristics of the waste materials used in that demonstration (Subtask 2.4). Two of the auger holes filled in October 1996 at the demonstration site were sampled and returned to the laboratory for compressive strength, mineralogic, and chemical testing. Construction and packing of eight laboratory leaching columns (lysimeters) was also initiated. Four columns were packed with samples of grout taken from cement-mixer trucks during the emplacement (October, 1996). A fifth column was loaded with crushed material cored from borehole {number_sign}10 two months after emplacement. Samples of dry FGD material were used to prepare water/FGD waste blends that were loaded to the final three columns. Two of these latter columns were loaded with a slurry produced by blending water with the FOD waste at levels similar to those used during emplacement (approx. 38 wt%). Differing amounts of slurry was loaded to each these columns and permitted to harden prior to initiating water additions. The final column was loaded with a blend of the dry FGD waste and a lesser amount of water (27.5 wt%) to both facilitate the percolation of water through the lysimeter and to permit subsequent comparisons to previous studies of the leaching behavior of dry FOD materials.1 Weekly additions of 100 mL of distilled water have been initiated. However, due to a significant lag time between the initiation of water feed and leachate-water breakthrough, leaching data are not available for presentation at this time.

  9. High volume-high value usage of flue gas desulfurization (FGD) by-products in underground mines: Phase 2 -- Field investigations. Quarterly report, January 1--March 31, 1998

    SciTech Connect

    1998-09-01

    The factors that control the strength of FBC ash grout were the focus of work during this quarter. Samples were prepared at different water contents and placed into cylindrical PVC molds. At specified curing intervals, the grout cylinders were subjected to unconfined compressive strength testing as per procedures described in previous reports. Chemical, mineralogical, and microscopical analyses were also conducted on the samples. It was found that higher curing temperatures significantly increase the strength gain rate of the FBC ash grout, in agreement with earlier results. As expected, water content also exerts a strong influence on the strength of the grout. The compressive strength data obtained for the laboratory-prepared samples are in excellent agreement with strength data obtained on grout placed in auger holes during the field demonstrations. The data also indicate that the field samples suffered negligible deterioration over the course of the curing period in the auger holes. Analysis of the laboratory prepared grout samples using XRD revealed a mineralogy similar to the field samples. A correspondence between ettringite abundance and compressive strength was observed only during grout curing. The formation of minerals such as ettringite is apparently a good indication that curing reactions are progressing and that the grout strength is increasing, but mineral distribution by itself does not explain or predict final strength. The microscopy data, in combination with geotechnical and XRD data, suggest that the strength of the grout is largely a function of the density of an amorphous (or finely crystalline) material that comprises the majority of the cured grout. Therefore, an increase in density of this material results in an increase in grout strength.

  10. Flue gas desulfurization: Physicochemical and biotechnological approaches

    SciTech Connect

    Pandey, R.A.; Biswas, R.; Chakrabarti, T.; Devotta, S.

    2005-07-01

    Various flue gas desulfurization processes - physicochemical, biological, and chemobiological - for the reduction of emission of SO{sub 2} with recovery of an economic by-product have been reviewed. The physicochemical processes have been categorized as 'once-through' and 'regenerable.' The prominent once-through technologies include wet and dry scrubbing. The wet scrubbing technologies include wet limestone, lime-inhibited oxidation, limestone forced oxidation, and magnesium-enhanced lime and sodium scrubbing. The dry scrubbing constitutes lime spray drying, furnace sorbent injection, economizer sorbent injection, duct sorbent injection, HYPAS sorbent injection, and circulating fluidized bed treatment process. The regenerable wet and dry processes include the Wellman Lord's process, citrate process, sodium carbonate eutectic process, magnesium oxide process, amine process, aqueous ammonia process, Berglau Forchung's process, and Shell's process. Besides these, the recently developed technologies such as the COBRA process, the OSCAR process, and the emerging biotechnological and chemobiological processes are also discussed. A detailed outline of the chemistry, the advantages and disadvantages, and the future research and development needs for each of these commercially viable processes is also discussed.

  11. Study on the stability of sorbents removing H{sub 2}S from hot coal gas

    SciTech Connect

    Li-Ping Chang; Zong-You Zhang; Xiu-Rong Ren; Fan Li; Ke-Chang Xie

    2009-01-15

    Mixed metal oxide containing iron with the high-sulfur capacity and reactivity is considered as one of the most favorable sorbents for desulfurization in hot gas. The stability and life of iron-based sorbents are the main challenges for the hot gas cleanup techniques. Not only the effect of gas atmosphere but also the effect of ZnO and MgO on the stability of iron-based sorbent was studied in this work. The mechanism and factors influencing sorbent stability are discussed. The results showed that the coexistence of CO and H{sub 2} result in the instability of the zinc-iron-based sorbents. The reaction of carbon deposit is the crucial step affecting the stability of sorbent for hot gas desulfurization. ZnO in the sorbent is adverse to the physical stability of the iron-based sorbents. MgO in the sorbent hardly affects the physical stability of the iron-based sorbents but improves the capacity of removing the hydrogen sulfide from hot coal gas at 773 K. 12 refs., 8 figs., 5 tabs.

  12. Laboratory evaluation of high-temperature sulfur removal sorbents for direct coal-fired turbines: Final report

    SciTech Connect

    Newby, R.A.; DeZubay, E.A.; Chamberlin, R.M.

    1987-06-01

    Direct coal-fired turbine concepts currently being developed require substantial levels of sulfur removal from high-temperature gas streams. Calcium-based sorbents, limestones, dolomites, limes and lime hydrates, are capable of sulfur removal in direct coal-fired turbine combustor environments at temperature up to 1200/degree/C. Two types of desulfurizer processes are considered in this report using calcium- based sorbents: fluidized bed desulfurizer using coarse sorbent particles (300-1000 ..mu..m), and entrained desulfurizer using fine sorbent particles (1-40 ..mu..m). Small-scale laboratory tests were performed on a variety of calcium-based sorbents to determine the kinetics of sulfation and sulfidation over ranges of conditions applicable to both types of desulfurizer processes. Correlations are developed in the report for the effect of pressure; temperature, and particle size. Engineering models are also developed for both desulfurizer types that incorporate the laboratory reaction kinetics and predict potential commercial performance and performance trends. It is concluded that both desulfurizer concepts can be effective in direct coal-fired turbines, with calcium-to-sulfur molar feed ratios ranging from 1.5 to 3.0, if the correct calcium-based sorbent is selected, and if applicable design and operating conditions are identified. Both desulfurizer concepts have limitations and key development requirements, and site and fuel specific engineering assessment is required to select the best concept for a given combustor system. The influence of the desulfurizer concepts on turbine protection, through their influence on particle loading and alkali release must also be assessed. 51 refs., 73 figs., 9 tabs.

  13. Development of regenerable copper-based sorbents for hot gas cleanup: Final technical report, September 1, 1995--August 31, 1996

    SciTech Connect

    Abbasian, J.; Slimane, R.B.; Wangerow, J.R.

    1997-05-01

    The overall objective of this study was to determine the effectiveness of the copper-chromite sorbent (developed in previous ICCI-funded projects) for longer duration application under optimum conditions in the temperature range of 550{degrees}-650{degrees}C to minimize sorbent reduction and degradation during the cyclic process. Three (3) formulations of attrition resistant granules of the copper chromite sorbent (i.e., CuCr-10, CuCr-21, and CuCr-29) as well as one (1) copper chromite sorbent in pellet form (i.e., CuCr-36) were selected for cyclic desulfurization tests. The desulfurization and regeneration capabilities of the selected formulations as well as the effects of operating parameters were determined, to identify the {open_quotes}best{close_quotes} sorbent formulation and the optimum operating conditions. The durability of the {open_quotes}best{close_quotes} sorbent formulation was determined in {open_quotes}long-term{close_quotes} multicycle tests conducted at the optimum operating conditions. The attrition resistance of the selected formulations were determined and compared with those of other sorbents, including a limestone, a dolomite, and a commercial zinc titanate sorbent. The results obtained in this study indicate that, the CuCr-29 sorbent has excellent attrition resistance and desulfurization performance, which are far superior to the commercial zinc titanate sorbents. The optimum desulfurization temperature in terms of sorbent efficiency and utilization appears to be about 600{degrees}C. Sorbent regeneration at 750{degrees}C ensured complete conversion of the copper sulfide to oxide without sulfate formation or reactivity deterioration in subsequent cycles.

  14. Theoretical approach for enhanced mass transfer effects in-duct flue gas desulfurization processes

    SciTech Connect

    Not Available

    1990-08-22

    While developing dry sorbent duct injection flue gas desulfurization processes may offer significant improvement in capital cost and process simplicity compared to wet scrubbing systems, the economics of this technology can be improved significantly by an improvement in sorbent utilization. While a general understanding of the mechanism by which the sorbents operate is known, a much more detailed knowledge of reaction rate-controlling phenomena, the role of inherent reactivity, and mass transfer effects and their interaction in needed. Objectives of this project are threefold: 1. Mass transfer investigation--determine the controlling physical and chemical processes that limit sorbent utilization. In particular, determine whether mass transfer is a controlling factor in in-duct flue gas desulfurization and establish the relative contributions of gas- and liquid-phase mass transfer and inherent sorbent reactivity. 2. Field test support--evaluate various sorbents, operating conditions and process schemes to support large-scale field testings at Meredosia and Beverly. 3. Mass transfer enhancement--examine various techniques that will enable sorbent utilization rates of at least 75 percent to be achieved. Sorbents investigated were Ca(OH){sub 2}, Mississippi hydrate and Mississippi slaked lime. Epsom Salt was investigated as an additive. Agglomeration of Ca(OH){sub 2} solids was also investigated. 3 refs., 92 figs., 23 tabs.

  15. Low temperature SO{sub 2} removal with solid sorbents in a circulating fluidized bed absorber. Quarterly report, May 1--July 31, 1992

    SciTech Connect

    Lee, S.K.; Keener, T.C.

    1992-08-12

    The nozzle installed in the circulating fluidized bed absorber (CFBA) was slightly modified because of a technical difficulty in making the small holes less than 100 {mu}m. The holes were punctured with a very tiny drill bits in diameter of 275 {mu}m, and the number of holes were adjusted. The 951 TGA (Du Pont Co.) was also modified for the kinetic information on the hydration and sulfation of limes under low temperatures. The modified thermalgravimetric analyzer (TGA) includes a syringe in order to simulate the water sprayings in a CFBA. Water droplets through the needle attached to the syringe are added onto the lime sample in a TGA. Two discrete ranges of Dravo limes were prepared as solid sorbents for sulfation tests. One ranged between 1095 {mu}m (16 mesh) and 2380 {mu}m (8 mesh) in diameter and the other ranged between 595 {mu}m (30 mesh) and 1095 {mu}m (16 mesh). The experimental methods for kinetic studies with TGA and for CFBA operation were established through the pre-operation of CFBA.

  16. Integration and testing of hot desulfurization and entrained-flow gasification for power generation systems

    SciTech Connect

    Robin, A.M.; Kassman, J.S.; Leininger, T.F.; Wolfenbarger, J.K.; Wu, C.M.; Yang, P.P.

    1991-09-01

    This second Topical Report describes the work that was completed between January 1, 1989 and December 31, 1990 in a Cooperative Agreement between Texaco and the US Department of Energy that began on September 30, 1987. During the period that is covered in this report, the development and optimization of in-situ and external desulfurization processes were pursued. The research effort included bench scale testing, PDU scoping tests, process economic studies and advanced instrument testing. Two bench scale studies were performed at the Research Triangle Institute with zinc titanate sorbent to obtain data on its cycle life, sulfur capacity, durability and the effect of chlorides. These studies quantify sulfur capture during simulated air and oxygen-blown gasification for two zinc titanate formulations. Eight PDU runs for a total of 20 days of operation were conducted to evaluate the performance of candidate sorbents for both in-situ and external desulfurization. A total of 47 tests were completed with oxygen and air-blown gasification. Candidate sorbents included iron oxide for in-situ desulfurization and calcium based and mixed metal oxides for external desulfurization. Gasifier performance and sorbent sulfur capture are compared for both air-blown and oxygen-blown operation.

  17. Attrition and changes in size distribution of lime sorbents during fluidization in a circulating fluidized bed absorber. Double quarterly report, January 1--August 31, 1993

    SciTech Connect

    Lee, Sang-Kwun; Keener, T.C.; Cook, J.L.; Khang, Soon Jai

    1993-12-31

    The experimental data of lime sorbent attrition obtained from attriton tests in a circulating fluidized bed absorber (CFBA) are represented. The results are interpreted as both the weight-based attrition rate and size-based attrition rate. The weight-based attrition rate constants are obtained from a modified second-order attrition model, incorporating a minimum fluidization weight, W{sub min}, and excess velocity. Furthermore, this minimum fluidization weight, or W{sub min} was found to be a function of both particle size and velocity. A plot of the natural log of the overall weight-based attrition rate constants (ln K{sub a}) for Lime 1 (903 MMD) at superficial gas velocities of 2 m/s, 2.35 m/s, and 2.69 m/s and for Lime 2 (1764 MMD) at superficial gas velocities of 2 m/s, 3 m/s, 4 m/s and 5 m/s versus the energy term, 1/(U-U{sub mf}){sup 2}, yielded a linear relationship. And, a regression coefficient of 0.9386 for the linear regression confirms that K{sub a} may be expressed in Arrhenius form. In addition, an unsteady state population model is represented to predict the changes in size distribution of bed materials during fluidization. The unsteady state population model was verified experimentally and the solid size distribution predicted by the model agreed well with the corresponding experimental size distributions. The model may be applicable for the batch and continuous operations of fluidized beds in which the solids size reduction is predominantly resulted from attritions and elutriations. Such significance of the mechanical attrition and elutriation is frequently seen in a fast fluidized bed as well as in a circulating fluidized bed.

  18. Crude oil desulfurization

    NASA Technical Reports Server (NTRS)

    Kalvinskas, J. J.; Hsu, G. C.; Ernest, J. B. (Inventor)

    1982-01-01

    High sulfur crude oil is desulfurized by a low temperature (25-80 C.) chlorinolysis at ambient pressure in the absence of organic solvent or diluent but in the presence of water (water/oil=0.3) followed by a water and caustic wash to remove sulfur and chlorine containing reaction products. The process described can be practiced at a well site for the recovery of desulfurized oil used to generate steam for injection into the well for enhanced oil recovery.

  19. Novel Sorbent to Clean Up Biogas for CHPs

    SciTech Connect

    Alptekin, Gökhan O.; Jayataman, Ambalavanan; Schaefer, Matthew; Ware, Michael; Hunt, Jennifer; Dobek, Frank

    2015-05-30

    In this project, TDA Research Inc. (TDA) has developed low-cost (on a per unit volume of gas processed basis), high-capacity expendable sorbents that can remove both the H2S and organic sulfur species in biogas to the ppb levels. The proposed sorbents will operate downstream of a bulk desulfurization system as a polishing bed to provide an essentially sulfur-free gas to a fuel cell (or any other application that needs a completely sulfur-free feed). Our sorbents use a highly dispersed mixed metal oxides active phase with desired modifiers prepared over on a mesoporous support. The support structure allows the large organic sulfur compounds (such as the diethyl sulfide and dipropyl sulfide phases with a large kinetic diameter) to enter the sorbent pores so that they can be adsorbed and removed from the gas stream.

  20. Metal sulfide initiators for metal oxide sorbent regeneration

    DOEpatents

    Turk, B.S.; Gupta, R.P.

    1999-06-22

    A process of regenerating a sulfided sorbent is provided. According to the process of the invention, a substantial portion of the energy necessary to initiate the regeneration reaction is provided by the combustion of a particulate metal sulfide additive. In using the particulate metal sulfide additive, the oxygen-containing gas used to regenerate the sulfided sorbent can be fed to the regeneration zone without heating or at a lower temperature than used in conventional processes wherein the regeneration reaction is initiated only by heating the oxygen-containing gas. The particulate metal sulfide additive is preferably an inexpensive mineral ore such as iron pyrite which does not adversely affect the regeneration or corresponding desulfurization reactions. The invention further includes a sorbent composition comprising the particulate metal sulfide additive in admixture with an active metal oxide sorbent capable of removing one or more sulfur compounds from a sulfur-containing gas stream. 1 fig.

  1. Metal sulfide initiators for metal oxide sorbent regeneration

    DOEpatents

    Turk, Brian S.; Gupta, Raghubir P.

    1999-01-01

    A process of regenerating a sulfided sorbent is provided. According to the process of the invention, a substantial portion of the energy necessary to initiate the regeneration reaction is provided by the combustion of a particulate metal sulfide additive. In using the particulate metal sulfide additive, the oxygen-containing gas used to regenerate the sulfided sorbent can be fed to the regeneration zone without heating or at a lower temperature than used in conventional processes wherein the regeneration reaction is initiated only by heating the oxygen-containing. The particulate metal sulfide additive is preferably an inexpensive mineral ore such as iron pyrite which does not adversely affect the regeneration or corresponding desulfurization reactions. The invention further includes a sorbent composition comprising the particulate metal sulfide additive in admixture with an active metal oxide sorbent capable of removing one or more sulfur compounds from a sulfur-containing gas stream.

  2. Metal sulfide initiators for metal oxide sorbent regeneration

    DOEpatents

    Turk, Brian S.; Gupta, Raghubir P.

    2001-01-01

    A process of regenerating a sulfided sorbent is provided. According to the process of the invention, a substantial portion of the energy necessary to initiate the regeneration reaction is provided by the combustion of a particulate metal sulfide additive. In using the particulate metal sulfide additive, the oxygen-containing gas used to regenerate the sulfided sorbent can be fed to the regeneration zone without heating or at a lower temperature than used in conventional processes wherein the regeneration reaction is initiated only by heating the oxygen-containing gas. The particulate metal sulfide additive is preferably an inexpensive mineral ore such as iron pyrite which does not adversely affect the regeneration or corresponding desulfurization reactions. The invention further includes a sorbent composition comprising the particulate metal sulfide additive in admixture with an active metal oxide sorbent capable of removing one or more sulfur compounds from a sulfur-containing gas stream.

  3. Pilot plant tests of Z-Sorb{trademark} sorbent

    SciTech Connect

    Greenwood, G.J.; Khare, G.P.; Kubicek, D.H.; Delzer, G.A.; Kinsinger, D.L.

    1995-06-01

    The objective of this work is to determine the long-term chemical reactivity and mechanical durability of Phillips Petroleum Company`s (PPCo`s) proprietary Z-Sorb{trademark} sorbent. Materials developed for fixed-, moving- and fluid bed desulfurization of coal derived gases at high pressure (5-20 atm) and moderate operating temperatures (600-1000{degrees}F) will be discussed.

  4. Flue gas desulfurization method and apparatus

    DOEpatents

    Madden, D.A.; Farthing, G.A.

    1998-09-29

    A combined furnace limestone injection and dry scrubber flue gas desulfurization (FGD) system collects solids from the flue gas stream in first particulate collection device located downstream of an outlet of a convection pass of the furnace and upstream of the dry scrubber. The collected solids are diverted to the dry scrubber feed slurry preparation system to increase sulfur oxide species removal efficiency and sorbent utilization. The level of lime in the feed slurry provided to the dry scrubber is thus increased, which enhances removal of sulfur oxide species in the dry scrubber. The decreased particulate loading to the dry scrubber helps maintain a desired degree of free moisture in the flue gas stream entering the dry scrubber, which enhances sulfur oxide species removal both in the dry scrubber and downstream particulate collector, normally a baghouse. 5 figs.

  5. Flue gas desulfurization method and apparatus

    DOEpatents

    Madden, D.A.; Farthing, G.A.

    1998-08-18

    A combined furnace limestone injection and dry scrubber flue gas desulfurization (FGD) system collects solids from the flue gas stream in first particulate collection device located downstream of an outlet of a convection pass of the furnace and upstream of the dry scrubber. The collected solids are diverted to the dry scrubber feed slurry preparation system to increase sulfur oxide species removal efficiency and sorbent utilization. The level of lime in the feed slurry provided to the dry scrubber is thus increased, which enhances removal of sulfur oxide species in the dry scrubber. The decreased particulate loading to the dry scrubber helps maintain a desired degree of free moisture in the flue gas stream entering the dry scrubber, which enhances sulfur oxide species removal both in the dry scrubber and downstream particulate collector, normally a baghouse. 5 figs.

  6. Flue gas desulfurization method and apparatus

    DOEpatents

    Madden, Deborah A.; Farthing, George A.

    1998-09-29

    A combined furnace limestone injection and dry scrubber flue gas desulfurization (FGD) system collects solids from the flue gas stream in first particulate collection device located downstream of an outlet of a convection pass of the furnace and upstream of the dry scrubber. The collected solids are diverted to the dry scrubber feed slurry preparation system to increase sulfur oxide species removal efficiency and sorbent utilization. The level of lime in the feed slurry provided to the dry scrubber is thus increased, which enhances removal of sulfur oxide species in the dry scrubber. The decreased particulate loading to the dry scrubber helps maintain a desired degree of free moisture in the flue gas stream entering the dry scrubber, which enhances sulfur oxide species removal both in the dry scrubber and downstream particulate collector, normally a baghouse.

  7. Flue gas desulfurization method and apparatus

    DOEpatents

    Madden, Deborah A.; Farthing, George A.

    1998-08-18

    A combined furnace limestone injection and dry scrubber flue gas desulfurization (FGD) system collects solids from the flue gas stream in first particulate collection device located downstream of an outlet of a convection pass of the furnace and upstream of the dry scrubber. The collected solids are diverted to the dry scrubber feed slurry preparation system to increase sulfur oxide species removal efficiency and sorbent utilization. The level of lime in the feed slurry provided to the dry scrubber is thus increased, which enhances removal of sulfur oxide species in the dry scrubber. The decreased particulate loading to the dry scrubber helps maintain a desired degree of free moisture in the flue gas stream entering the dry scrubber, which enhances sulfur oxide species removal both in the dry scrubber and downstream particulate collector, normally a baghouse.

  8. Recent advances in flue gas desulfurization technologies

    SciTech Connect

    Pan, Y.S.

    1991-01-01

    Recent advances in flue gas desulfurization (FGD) technologies are reported. The technological advances include conventional wet FGD system improvements, advanced wet FGD system development, spray dryer system operations, technologies for furnace sorbent injections, post-combustion dry technologies, combined SO{sub 2}/NO{sub x} technologies, and several emerging FGD technologies. In addition, progress of by-product utilization that affects the operating cost of FGD systems is described. Economics of some commercially available and nearly maturing FGD technologies is also discussed. The materials included in this report are obtained from technical presentations made through September 1990, at several national and international conferences. This report is intended to document current advances and status of various FGD technologies. 101 refs., 16 figs.

  9. Fluidized bed coal desulfurization

    NASA Technical Reports Server (NTRS)

    Ravindram, M.

    1983-01-01

    Laboratory scale experiments were conducted on two high volatile bituminous coals in a bench scale batch fluidized bed reactor. Chemical pretreatment and posttreatment of coals were tried as a means of enhancing desulfurization. Sequential chlorination and dechlorination cum hydrodesulfurization under modest conditions relative to the water slurry process were found to result in substantial sulfur reductions of about 80%. Sulfur forms as well as proximate and ultimate analyses of the processed coals are included. These studies indicate that a fluidized bed reactor process has considerable potential for being developed into a simple and economic process for coal desulfurization.

  10. High-Temperature Desulfurization of Heavy Fuel-Derived Reformate Gas Streams for SOFC Applications

    NASA Technical Reports Server (NTRS)

    Flytzani-Stephanopoulos, Maria; Surgenor, Angela D.

    2007-01-01

    Desulfurization of the hot reformate gas produced by catalytic partial oxidation or autothermal reforming of heavy fuels, such as JP-8 and jet fuels, is required prior to using the gas in a solid oxide fuel cell (SOFC). Development of suitable sorbent materials involves the identification of sorbents with favorable sulfidation equilibria, good kinetics, and high structural stability and regenerability at the SOFC operating temperatures (650 to 800 C). Over the last two decades, a major barrier to the development of regenerable desulfurization sorbents has been the gradual loss of sorbent performance in cyclic sulfidation and regeneration at such high temperatures. Mixed oxide compositions based on ceria were examined in this work as regenerable sorbents in simulated reformate gas mixtures and temperatures greater than 650 C. Regeneration was carried out with dilute oxygen streams. We have shown that under oxidative regeneration conditions, high regeneration space velocities (greater than 80,000 h(sup -1)) can be used to suppress sulfate formation and shorten the total time required for sorbent regeneration. A major finding of this work is that the surface of ceria and lanthanan sorbents can be sulfided and regenerated completely, independent of the underlying bulk sorbent. This is due to reversible adsorption of H2S on the surface of these sorbents even at temperatures as high as 800 C. La-rich cerium oxide formulations are excellent for application to regenerative H2S removal from reformate gas streams at 650 to 800 C. These results create new opportunities for compact sorber/regenerator reactor designs to meet the requirements of solid oxide fuel cell systems at any scale.

  11. Desulfurization with a modified limestone formulation in an industrial CFBC boiler

    SciTech Connect

    Young Goo Park; Seung Ho Kim

    2006-02-01

    This work presents a practical result of experimental investigation of the limestone particle size effect on de-SOx from a circulating fluidized bed combustion (CFBC) boiler that burns domestic anthracite and is the first industrial scale in Korea. Because of combustion problems such as clinker formation, fine limestone has not been used as a desulfurization agent. The present test, however, showed that higher content (up to 50%) of the particles under 0.1 mm did not entail any malfunction in a modern CFBC system. In addition, the desulfurization efficiency was found to be comparable to the old mode of limestone sorbents. 17 refs., 4 figs., 3 tabs.

  12. Handling, transport and dispersion of sorbent powder for in-furnace injection. Final report

    SciTech Connect

    Fan, Liang-Shih; Abou-Zeida, E.; Liang, Shu-Chien; Luo, Xukun

    1996-02-01

    The focus of this project is on sorbent injection technologies using dry, calcium-based sorbents for high-sulfur coal flue gas desulfurization. The goal is to provide research findings on handling, transport and dispersion of sorbent powder, aimed at improving SO{sub 2} (to at least 90%) removal and increasing sorbent utilization in a cost-effective fashion. With this goal, the purpose of this project is to investigate the fundamental aspects of powder technology relevant to the fine sorbent powders, and to provide means of improving sorbent performance through superior dispersion and reduced dispersed particle size. The fifth year`s project contains three phases, Phase I ``Characterization of Electrostatic Properties``, Phase II ``Cohesive Strength of Modified Sorbents``. and Phase III ``Modeling of Powder Dispersion``. Work under Phase I involves characterization of the sorbents in terms of their electrostatic properties. Phase II investigates the flow properties of several calcium-based sorbents under different handling and transporting conditions. In Phase III, experimental studies are performed to measure the sorbent powder size distribution in different apparatuses and under different conditions. The population balance model proposed in previous studies can reasonably simulate these experiment results. These three areas of investigations are discussed in this report.

  13. Pressurized fluidized-bed hydroretorting of Eastern oil shales -- Sulfur control. Topical report for Subtask 3.1, In-bed sulfur capture tests; Subtask 3.2, Electrostatic desulfurization; Subtask 3.3, Microbial desulfurization and denitrification

    SciTech Connect

    Roberts, M.J.; Abbasian, J.; Akin, C.; Lau, F.S.; Maka, A.; Mensinger, M.C.; Punwani, D.V.; Rue, D.M.; Gidaspow, D.; Gupta, R.; Wasan, D.T.; Pfister, R.M.: Krieger, E.J.

    1992-05-01

    This topical report on ``Sulfur Control`` presents the results of work conducted by the Institute of Gas Technology (IGT), the Illinois Institute of Technology (IIT), and the Ohio State University (OSU) to develop three novel approaches for desulfurization that have shown good potential with coal and could be cost-effective for oil shales. These are (1) In-Bed Sulfur Capture using different sorbents (IGT), (2) Electrostatic Desulfurization (IIT), and (3) Microbial Desulfurization and Denitrification (OSU and IGT). The objective of the task on In-Bed Sulfur Capture was to determine the effectiveness of different sorbents (that is, limestone, calcined limestone, dolomite, and siderite) for capturing sulfur (as H{sub 2}S) in the reactor during hydroretorting. The objective of the task on Electrostatic Desulfurization was to determine the operating conditions necessary to achieve a high degree of sulfur removal and kerogen recovery in IIT`s electrostatic separator. The objectives of the task on Microbial Desulfurization and Denitrification were to (1) isolate microbial cultures and evaluate their ability to desulfurize and denitrify shale, (2) conduct laboratory-scale batch and continuous tests to improve and enhance microbial removal of these components, and (3) determine the effects of processing parameters, such as shale slurry concentration, solids settling characteristics, agitation rate, and pH on the process.

  14. Methods, systems, and devices for deep desulfurization of fuel gases

    DOEpatents

    Li, Liyu; King, David L.; Liu, Jun; Huo, Qisheng

    2012-04-17

    A highly effective and regenerable method, system and device that enables the desulfurization of warm fuel gases by passing these warm gasses over metal-based sorbents arranged in a mesoporous substrate. This technology will protect Fischer-Tropsch synthesis catalysts and other sulfur sensitive catalysts, without drastic cooling of the fuel gases. This invention can be utilized in a process either alone or alongside other separation processes, and allows the total sulfur in such a gas to be reduced to less than 500 ppb and in some instances as low as 50 ppb.

  15. Regenerable sorbents for mercury capture in simulated coal combustion flue gas.

    PubMed

    Rodríguez-Pérez, Jorge; López-Antón, M Antonia; Díaz-Somoano, Mercedes; García, Roberto; Martínez-Tarazona, M Rosa

    2013-09-15

    This work demonstrates that regenerable sorbents containing nano-particles of gold dispersed on an activated carbon are efficient and long-life materials for capturing mercury species from coal combustion flue gases. These sorbents can be used in such a way that the high investment entailed in their preparation will be compensated for by the recovery of all valuable materials. The characteristics of the support and dispersion of gold in the carbon surface influence the efficiency and lifetime of the sorbents. The main factor that determines the retention of mercury and the regeneration of the sorbent is the presence of reactive gases that enhance mercury retention capacity. The capture of mercury is a consequence of two mechanisms: (i) the retention of elemental mercury by amalgamation with gold and (ii) the retention of oxidized mercury on the activated carbon support. These sorbents were specifically designed for retaining the mercury remaining in gas phase after the desulfurization units in coal power plants.

  16. Regenerable sorbents for mercury capture in simulated coal combustion flue gas.

    PubMed

    Rodríguez-Pérez, Jorge; López-Antón, M Antonia; Díaz-Somoano, Mercedes; García, Roberto; Martínez-Tarazona, M Rosa

    2013-09-15

    This work demonstrates that regenerable sorbents containing nano-particles of gold dispersed on an activated carbon are efficient and long-life materials for capturing mercury species from coal combustion flue gases. These sorbents can be used in such a way that the high investment entailed in their preparation will be compensated for by the recovery of all valuable materials. The characteristics of the support and dispersion of gold in the carbon surface influence the efficiency and lifetime of the sorbents. The main factor that determines the retention of mercury and the regeneration of the sorbent is the presence of reactive gases that enhance mercury retention capacity. The capture of mercury is a consequence of two mechanisms: (i) the retention of elemental mercury by amalgamation with gold and (ii) the retention of oxidized mercury on the activated carbon support. These sorbents were specifically designed for retaining the mercury remaining in gas phase after the desulfurization units in coal power plants. PMID:23876255

  17. Hot Coal Gas Desulfurization With Manganese-Based Sorbents

    SciTech Connect

    Berns, J.J.; Hepworth, M.T.

    1996-12-31

    The objective of this project is to develop a pellet formulation which is capable of achieving low sulfur partial pressures and a high capacity for sulfur, loaded from a hot fuel gas and which is readily regenerable. Furthermore the pellet must be strong for potential use in a fluidized and regenerable over many cycles of loading and regeneration. Regeneration should be in air or oxygen-depleted air to produce a high-concentration sulfur dioxide. Fixed-bed tests were conducted with several formulations of manganese sesquioxide and titania, and alumina. They were subject to a simplified fuel gas of the oxygen-blown Shell type spiked with a 30,000 ppmv concentration of H{sub 2}S. Pellet crush strengths for 4 and 2 mm diameter pellets was typically 12 lbs per pellet and 4 lbs per pellet, respectively. For the most favorable of the formulations tested and under the criteria of break-through at less than 100 ppmv H{sub 2}S and loading temperatures of 5000 {degrees}C and an empty-bed space velocity of 4, 000 per hour, breakthrough occurred an effective loading of sulfur of 27 to 29% over 5 loading and regeneration cycles. At 90% of this saturation condition, the observed level of H{sub 2}S was below 10 ppmv. For regeneration, a temperature of 9000 {degrees}C is required to dissociate the sulfide into sulfur dioxide using air at atmospheric pressure. The mean sulfur dioxide concentration which is achieved during regeneration is 8% with empty-bed space velocities of 700/hr. TGA tests on individual pellets indicate that bentonite is not desirable as a bonding material and that Mn/Ti ratios higher than 7:1 produce relatively non-porous pellets. Whereas the reactivity is rapid below 12% conversion, the kinetics of conversion decreased significantly above this level. This observation may be the result of plugging of the pellet pores with sulfided product creating inaccessible pore volumes or alternately an increase in diffusional resistance by formation of MnS.

  18. Ultra-deep adsorptive desulfurization of a model diesel fuel on regenerable Ni-Cu/γ-Al₂O₃ at low temperatures in absence of hydrogen.

    PubMed

    Mansouri, Ali; Khodadadi, Abbas Ali; Mortazavi, Yadollah

    2014-04-30

    A model diesel fuel containing 250 ppmw sulfur (as dibenzothiophene) in n-hexadecane was desulfurized at low temperatures in absence of hydrogen, down to about zero ppmwS on a novel adsorbent of well dispersed 3-12 nm Nix-Cu10-x (x=Ni wt%) nanoparticles formed by impregnation on γ-Al2O3 and reduced in H2 at 275 or 450°C. The sorbents were characterized by XRD, TEM-EDX, FESEM-EDS, H2-TPR, TPO, BJH and BET surface area measurement techniques. Effects of various parameters comprising Cu content, reduction and desulfurization temperatures, inhibition by naphthalene, and regeneration of spent sorbents were investigated. As copper is added to nickel: (a) the sorbent reduction temperature shifts to dramatically lower values, (b) sulfur adsorption capacity of the sorbents at lower reduction and desulfurization temperatures is significantly improved, and when 14 wt% Ni5Cu5 sorbent is added to the fuel, the sulfur content reduces from 250 ppmwS to about zero in less than 1 min, (c) loss of adsorption capacity after the regeneration of the spent sorbent reduced at 275°C is significantly diminished, and (d) the selectivity of the sorbents to dibenzothiophene in the presence of naphthalene is improved. A higher reduction temperature tends to agglomerate nickel nanoparticles and reduce the sulfur adsorption capacity.

  19. Recovery and recycling of limestone in LEC flue gas desulfurization

    SciTech Connect

    Gardner, N.C.; Adler, R.J.; Lin, Y.C.; Unger, M.E.; Lux, K.W. )

    1992-03-01

    Prudich et al. have proposed an attractive technology called Limestone Emission Control (LEC) for removing sulfur dioxide from flue gases. Beds of 1/8 inch wet limestone particles absorb the sulfur dioxide from the gases. Sulfates and sulfites deposit on the surfaces of the particles, limiting their utilization to about 20%. The unreacted portion of the limestone can be recovered by mechanical grinding and recycling, enabling high overall sorbent utilization. Favorable economic costs derive from small equipment, simplicity, and low sorbent cost. Our research concentrates on selecting and testing on a laboratory scale suitable candidate dry and wet grinding methods for recovering limestone in LEC flue from desulfurization. A wet grinding method based on the impeller fluidizer, a new type of slurry processor, receives special attention. The impeller fluidizer is a dosed cylindrical vessel with an impeller at one end. It combines the operations of wet grinding, washing, and transporting the spent and recovered limestone as an aqueous slurry.

  20. Enzymatic desulfurization of coal

    SciTech Connect

    Boyer, Y.N.; Crooker, S.C.; Kitchell, J.P.; Nochur, S.V.

    1991-05-16

    The overall objective of this program was to investigate the feasibility of an enzymatic desulfurization process specifically intended for organic sulfur removal from coal. Toward that end, a series of specific objectives were defined: (1) establish the feasibility of (bio)oxidative pretreatment followed by biochemical sulfate cleavage for representative sulfur-containing model compounds and coals using commercially-available enzymes; (2) investigate the potential for the isolation and selective use of enzyme preparations from coal-utilizing microbial systems for desulfurization of sulfur-containing model compounds and coals; and (3) develop a conceptual design and economic analysis of a process for enzymatic removal of organic sulfur from coal. Within the scope of this program, it was proposed to carry out a portion of each of these efforts concurrently. (VC)

  1. Enzymatic desulfurization of coal

    SciTech Connect

    Marquis, J.K. . School of Medicine); Kitchell, J.P. )

    1988-10-07

    Our current efforts to develop clean coal technology, emphasize the advantages of enzymatic desulfurization techniques and have specifically addressed the potential of using partially-purified extracellular microbial enzymes or commercially available enzymes. Our work is focused on the treatment of model'' organic sulfur compounds such as dibenzothiophene (DBT) and ethylphenylsulfide (EPS). Furthermore, we are designing experiments to facilitate the enzymatic process by means of a hydrated organic solvent matrix.

  2. Enzymatic desulfurization of coal

    SciTech Connect

    Boyer, Y.N.; Crooker, S.C.; Kitchell, J.P.; Nochur, S.V. ); Marquis, J.K. . School of Medicine)

    1989-06-16

    Our current efforts to develop clean coal technology emphasize the advantages of enzymatic desulfurization techniques and have specifically addressed the potential of using partially-purified extracellular microbial enzymes as well as commercially available enzymes. Our work is focused on the treatment of model'' organic sulfur compounds such as dibenzothiophene (DBT) and ethylphenylsulfide (EPS). Furthermore, we are designing experiments to facilitate the enzymatic process by means of a hydrated organic solvent matrix.

  3. Fluidized bed desulfurization

    NASA Technical Reports Server (NTRS)

    Ravindram, M.; Kallvinskas, J. J. (Inventor)

    1985-01-01

    High sulfur content carbonaceous material, such as coal is desulfurized by continuous fluidized suspension in a reactor with chlorine gas, inert dechlorinating gas and hydrogen gas. A source of chlorine gas, a source of inert gas and a source of hydrogen gas are connected to the bottom inlet through a manifold and a heater. A flow controler operates servos in a manner to continuously and sequentially suspend coal in the three gases. The sulfur content is reduced at least 50% by the treatment.

  4. Enzymatic desulfurization of coal

    SciTech Connect

    Marquis, J.K. . School of Medicine); Kitchell, J.P. )

    1988-12-15

    Our current efforts to develop clean coal technology emphasize the advantages of enzymatic desulfurization techniques and have specifically addressed the potential of using partially-purified extracellular microbial enzymes or commercially available enzymes. Our work is focused on the treatment of model'' organic sulfur compounds such as dibenzothiophene (DBT) and ethylphenylsulfide (EPS). Furthermore, we are designing experiments to facilitate the enzymatic process by means of a hydrated organic solvent matrix.

  5. Coal Liquefaction desulfurization process

    DOEpatents

    Givens, Edwin N.

    1983-01-01

    In a solvent refined coal liquefaction process, more effective desulfurization of the high boiling point components is effected by first stripping the solvent-coal reacted slurry of lower boiling point components, particularly including hydrogen sulfide and low molecular weight sulfur compounds, and then reacting the slurry with a solid sulfur getter material, such as iron. The sulfur getter compound, with reacted sulfur included, is then removed with other solids in the slurry.

  6. Sorbent development for transport reactor applications

    SciTech Connect

    Gupta, R.P.; Turk, B.S.; Vierheilig, A.A.; Cicero, D.C.

    1998-12-31

    Advanced power generation systems employing gasification of carbonaceous fuels offer increased efficiency and reduced emissions over pulverized coal-fired boiler systems currently in service. Integrated gasification combined cycle (IGCC) is the leading gasification-based system which is being advanced worldwide to produce electricity from carbonaceous fuels. This technology has the potential to reduce sulfur and nitrogen emissions the precursors of acid-rain and could lead to significant reductions in carbon dioxide emissions, which, it is believed, are major contributors to global warming. Successful commercialization of the IGCC technology requires economic competitiveness with other power generation systems. This economic competitiveness has propelled research and development of gas desulfurization systems. A number of mixed metal oxide sorbents have been investigated for removal of reduced sulfur species (H{sub 2}S, COS, CS{sub 2}, etc.) at high-temperature, high-pressure (HTHP) conditions, the best candidates have been the ZnO-based sorbents because of their ability to reduce the fuel gas sulfur level to a few parts per million by volume (ppmv). The work described in this paper deals with the development of zinc titanate sorbents for transport reactor applications.

  7. Highly Attrition Resistant Zinc Oxide-Based Sorbents for H2S Removal by Spray Drying Technique

    SciTech Connect

    Ryu, C.K.; Lee, J.B.; Ahn, D.H.; Kim, J.J.; Yi, C.K.

    2002-09-19

    Primary issues for the fluidized-bed/transport reactor process are high attrition resistant sorbent, its high sorption capacity and regenerability, durability, and cost. The overall objective of this project is the development of a superior attrition resistant zinc oxide-based sorbent for hot gas cleanup in integrated coal gasification combined cycle (IGCC). Sorbents applicable to a fluidized-bed hot gas desulfurization process must have a high attrition resistance to withstand the fast solid circulation between a desulfurizer and a regenerator, fast kinetic reactions, and high sulfur sorption capacity. The oxidative regeneration of zinc-based sorbent usually initiated at greater than 600 C with highly exothermic nature causing deactivation of sorbent as well as complication of sulfidation process by side reaction. Focusing on solving the sorbent attrition and regenerability of zinc oxide-based sorbent, we have adapted multi-binder matrices and direct incorporation of regeneration promoter. The sorbent forming was done with a spray drying technique that is easily scalable to commercial quantity.

  8. Coal desulfurization with iron pentacarbonyl

    NASA Technical Reports Server (NTRS)

    Hsu, G. C.

    1979-01-01

    Coal desulfurization with iron pentacarbonyl treatment under mild conditions removes up to eighty percent of organic sulfur. Preliminary tests on treatment process suggest it may be economical enough to encourage investigation of use for coal desulfurization. With mild operating conditions, process produces environmentally-acceptable clean coal at reasonable cost.

  9. Characterization and optimization of sorbents utilized for emission control during coal gasification. Final report

    SciTech Connect

    Huque, Z.; Mei, D.; Zhou, J.

    1998-07-14

    To overcome the shortage of components required for high temperature operation required by current IGCC and PFBC systems, researchers recently have decided that the power systems can be optimized within an operation temperature range of 343 to 538 C. The findings of this research work support the use of iron oxides as an efficient, disposable hot gas desulfurization sorbent candidate to meet the temperature range of 343 to 538 C to further optimize its application for hot gas desulfurization. A parametric study was performed to characterize the controlling parameters dominating the absorption process of hydrogen sulfide by waste iron oxide as a sorbent alternative within a stringent environment with the use of simulated KRW reducing gas. The major parameters studied for hot gas desulfurization with the use of waste iron oxide; mixed in coal ash and reacted with hot sulfurized gas; in hot gas stream include (1) dust cake permeability during heavy dust loading, (2) feasibility of dust cake removal with current back pulse cleaning technology, (3) the reaction temperature, (4) the space velocity of the gas stream. Based on the parametric testing performed on hot gas desulfurization and particulate filtration, the test results of this study indicate that the simultaneous operation of hot gas desulfurization and particulate filtration is feasible. The significant savings of capital investment, system operation and maintenance justify the use of iron oxides as an excellent candidate for hot gas cleanup.

  10. Pore structure effects on Ca-based sorbent sulfation capacity at medium temperatures: activated carbon as sorbent/catalyst support.

    PubMed

    Tseng, Hui-Hsin; Wey, Ming-Yen; Lin, Chiou-Liang; Chang, Yu-Chen

    2002-11-01

    The reaction between three different Ca-based sorbents and SO2 were studied in a medium temperature range (473-773 K). The largest SO2 capture was found with Ca(OH)2 at 773 K, 126.31 mg SO2 x g Ca(OH)2(-1), and the influence of SO2 concentration on the sorbent utilization was observed. Investigations of the internal porous structure of Ca-based sorbents showed that the initial reaction rate was controlled by the surface area, and once the sulfated products were produced, pore structure dominated. To increase the surface area of Ca-based sorbents available to interact with and retain SO2, one kind of CaO/ activated carbon (AC) sorbent/catalyst was prepared to study the effect of AC on the dispersion of Ca-based materials. The results indicated that the Ca-based material dispersed on high-surface-area AC had more capacities for SO2 than unsupported Ca-based sorbents. The initial reaction rates of the reaction between SO2 and Ca-based sorbents and the prepared CaO/AC sorbents/catalysts were measured. Results showed that the reaction rate apparently increased with the presence of AC. It was concluded that CaO/AC was the active material in the desulfurization reaction. AC acting as the support can play a role to supply O2 to increase the affinity to SO2. Moreover, when AC is acting as a support, the surface oxygen functional group formed on the surface of AC can serve as a new site for SO2 adsorption.

  11. BENCH-SCALE DEMONSTRATION OF HOT-GAS DESULFURIZATION TECHNOLOGY

    SciTech Connect

    Unknown

    2000-09-01

    The U.S. Department of Energy (DOE), National Energy Technology Laboratory (NETL), is sponsoring research in advanced methods for controlling contaminants in hot coal gasifier gas (coal-derived fuel-gas) streams of integrated gasification combined-cycle (IGCC) power systems. The hot gas cleanup work seeks to eliminate the need for expensive heat recovery equipment, reduce efficiency losses due to quenching, and minimize wastewater treatment costs. Hot-gas desulfurization research has focused on regenerable mixed-metal oxide sorbents that can reduce the sulfur in coal-derived fuel-gas to less than 20 ppmv and can be regenerated in a cyclic manner with air for multicycle operation. Zinc titanate (Zn{sub 2}TiO{sub 4} or ZnTiO{sub 3}), formed by a solid-state reaction of zinc oxide (ZnO) and titanium dioxide (TiO{sub 2}), is currently one of the leading sorbents. Overall chemical reactions with Zn{sub 2}TiO{sub 4} during the desulfurization (sulfidation)-regeneration cycle are shown. The sulfidation/regeneration cycle can be carried out in a fixed-bed, moving-bed, or fluidized-bed reactor configuration. The fluidized-bed reactor configuration is most attractive because of several potential advantages including faster kinetics and the ability to handle the highly exothermic regeneration to produce a regeneration offgas containing a constant concentration of SO{sub 2}.

  12. BENCH-SCALE DEMONSTRATION OF HOT-GAS DESULFURIZATION TECHNOLOGY

    SciTech Connect

    Unknown

    1999-07-01

    The U.S. Department of Energy (DOE), National Energy Technology Laboratory (NETL), is sponsoring research in advanced methods for controlling contaminants in hot coal gasifier gas (coal-derived fuel-gas) streams of integrated gasification combined-cycle (IGCC) power systems. The hot gas cleanup work seeks to eliminate the need for expensive heat recovery equipment, reduce efficiency losses due to quenching, and minimize wastewater treatment costs. Hot-gas desulfurization research has focused on regenerable mixed-metal oxide sorbents that can reduce the sulfur in coal-derived fuel-gas to less than 20 ppmv and can be regenerated in a cyclic manner with air for multicycle operation. Zinc titanate (Zn{sub 2}TiO{sub 4} or ZnTiO{sub 3}), formed by a solid-state reaction of zinc oxide (ZnO) and titanium dioxide (TiO{sub 2}), is currently one of the leading sorbents. Overall chemical reactions with Zn{sub 2}TiO{sub 4} during the desulfurization (sulfidation)-regeneration cycle are shown. The sulfidation/regeneration cycle can be carried out in a fixed-bed, moving-bed, or fluidized-bed reactor configuration. The fluidized-bed reactor configuration is most attractive because of several potential advantages including faster kinetics and the ability to handle the highly exothermic regeneration to produce a regeneration offgas containing a constant concentration of SO{sub 2}.

  13. Two-stage coal gasification and desulfurization apparatus

    DOEpatents

    Bissett, Larry A.; Strickland, Larry D.

    1991-01-01

    The present invention is directed to a system which effectively integrates a two-stage, fixed-bed coal gasification arrangement with hot fuel gas desulfurization of a first stream of fuel gas from a lower stage of the two-stage gasifier and the removal of sulfur from the sulfur sorbent regeneration gas utilized in the fuel-gas desulfurization process by burning a second stream of fuel gas from the upper stage of the gasifier in a combustion device in the presence of calcium-containing material. The second stream of fuel gas is taken from above the fixed bed in the coal gasifier and is laden with ammonia, tar and sulfur values. This second stream of fuel gas is burned in the presence of excess air to provide heat energy sufficient to effect a calcium-sulfur compound forming reaction between the calcium-containing material and sulfur values carried by the regeneration gas and the second stream of fuel gas. Any ammonia values present in the fuel gas are decomposed during the combustion of the fuel gas in the combustion chamber. The substantially sulfur-free products of combustion may then be combined with the desulfurized fuel gas for providing a combustible fluid utilized for driving a prime mover.

  14. Sol-gel auto-combustion synthesis of zinc ferrite for moderate temperature desulfurization

    SciTech Connect

    Rongjun Zhang; Jiejie Huang; Jiantao Zhao; Zhiqiang Sun; Yang Wang

    2007-09-15

    Zinc ferrite as a desulfurization sorbent with an average crystallite size of about 36 nm was synthesized by a sol-gel auto-combustion method. The precursor for the sorbent was a gel obtained from metal nitrates and citric acid by a sol process. The nitrate-citrate gel exhibits a self-propagating combustion behavior, and after combustion, it can transform into a nanosized spinel structured zinc ferrite directly. The prepared sorbent has a larger specific surface area and higher reactivity when compared with the sorbent achieved by a solid mixing method, and it could efficiently reduce the H{sub 2}S concentration from 6000 ppm to less than 2 ppm at a moderate temperature range. The sulfur capacity at 400{sup o}C reaches about 38.5 g of sulfur/100 g of sorbent, which corresponds to 96.4% of the theoretical value. The temperature programmed oxidation test for the sulfided sorbent shows that the most sulfur is desorbed before 500{sup o}C. XRD results confirm that the sulfided sample after exposure to a 5% O{sub 2}/N{sub 2} gas mixture at 500{sup o}C can be regenerated completely, which indicates that the regeneration temperature of the sorbent prepared by the sol-gel auto-combustion method could be greatly reduced. 40 refs., 10 figs., 2 tabs.

  15. Regenerable solid imine sorbents

    DOEpatents

    Gray, McMahan; Champagne, Kenneth J.; Fauth, Daniel; Beckman, Eric

    2013-09-10

    Two new classes of amine-based sorbents are disclosed. The first class comprises new polymer-immobilized tertiary amine sorbents; the second class new polymer-bound amine sorbents. Both classes are tailored to facilitate removal of acid anhydrides, especially carbon dioxide (CO.sub.2), from effluent gases. The amines adsorb acid anhydrides in a 1:1 molar ratio. Both classes of amine sorbents adsorb in the temperature range from about 20.degree. C. upwards to 90.degree. C. and can be regenerated by heating upwards to 100.degree. C.

  16. Irradiation pretreatment for coal desulfurization

    NASA Technical Reports Server (NTRS)

    Hsu, G. C.

    1979-01-01

    Process using highly-penetrating nuclear radiation (Beta and Gamma radiation) from nuclear power plant radioactive waste to irradiate coal prior to conventional desulfurization procedures increases total extraction of sulfur.

  17. Carbon Dioxide Capture from Flue Gas Using Dry, Regenerable Sorbents

    SciTech Connect

    David A. Green; Thomas O. Nelson; Brian S. Turk; Paul D. Box; Andreas Weber; Raghubir P. Gupta

    2006-01-01

    This report describes research conducted between October 1, 2005, and December 31, 2005, on the use of dry regenerable sorbents for removal of carbon dioxide (CO{sub 2}) from flue gas from coal combustion. A field test was conducted to examine the extent to which RTI's supported sorbent can be regenerated in a heated, hollow screw conveyor. This field test was conducted at the facilities of a screw conveyor manufacturer. The sorbent was essentially completely regenerated during this test, as confirmed by thermal desorption and mass spectroscopy analysis of the regenerated sorbent. Little or no sorbent attrition was observed during 24 passes through the heated screw conveyor system. Three downflow contactor absorption tests were conducted using calcined sodium bicarbonate as the absorbent. Maximum carbon dioxide removals of 57 and 91% from simulated flue gas were observed at near ambient temperatures with water-saturated gas. These tests demonstrated that calcined sodium carbonate is not as effective at removing CO{sub 2} as are supported sorbents containing 10 to 15% sodium carbonate. Delivery of the hollow screw conveyor for the laboratory-scale sorbent regeneration system was delayed; however, construction of other components of this system continued during the quarter.

  18. Integration and testing of hot desulfurization and entrained-flow gasification for power generation systems. Phase 2, Process optimization: Volume 1, Program summary and PDU operations

    SciTech Connect

    Robin, A.M.; Kassman, J.S.; Leininger, T.F.; Wolfenbarger, J.K.; Wu, C.M.; Yang, P.P.

    1991-09-01

    This second Topical Report describes the work that was completed between January 1, 1989 and December 31, 1990 in a Cooperative Agreement between Texaco and the US Department of Energy that began on September 30, 1987. During the period that is covered in this report, the development and optimization of in-situ and external desulfurization processes were pursued. The research effort included bench scale testing, PDU scoping tests, process economic studies and advanced instrument testing. Two bench scale studies were performed at the Research Triangle Institute with zinc titanate sorbent to obtain data on its cycle life, sulfur capacity, durability and the effect of chlorides. These studies quantify sulfur capture during simulated air and oxygen-blown gasification for two zinc titanate formulations. Eight PDU runs for a total of 20 days of operation were conducted to evaluate the performance of candidate sorbents for both in-situ and external desulfurization. A total of 47 tests were completed with oxygen and air-blown gasification. Candidate sorbents included iron oxide for in-situ desulfurization and calcium based and mixed metal oxides for external desulfurization. Gasifier performance and sorbent sulfur capture are compared for both air-blown and oxygen-blown operation.

  19. New regents for coal desulfurization

    SciTech Connect

    Buchanan, D.H.; Kalembasa, S.; Olson, D.; Wang, S.; Warfel, L.

    1991-01-01

    The primary goal of this project was development and exploration of potential new desulfurization reagents for the removal of organic sulfur'' from Illinois coals by mild chemical methods. Potential new desulfurization reagents were investigated using organic sulfur compounds of the types thought to be present in coals. Reagents included low-valent metal complexes based on nickel and on iron as well as possible Single Electron Transfer reagents. Soluble coal extracts served as second generation model compounds during this reagent development project.

  20. Enzymatic desulfurization of coal

    SciTech Connect

    Boyer, Y.N.; Crooker, S.C.; Kitchell, J.P.; Nochur, S.V. ); Marquis, J.K. . School of Medicine)

    1989-11-07

    Our experimental approach focuses on the use of enzymes which catalyze the addition of oxygen to organic compounds. In tailoring the application of these enzymes to coal processing, we are particularly interested in ensuring that oxidation occurs at sulfur and not at carbon-carbon bonds. Previous studies with DBT have shown that the reaction most frequently observed in microbial oxidative pathways is one in which DBT is oxidized at ring carbons. These reactions, as we have said, are accompanied by a considerable decrease in the energy content of the compound. In addition, microbial pathways have been identified in which the sulfur atom is sequentially oxidized to sulfoxide, to sulfone, to sulfonate, and finally to sulfuric acid. In this case, the fuel value of the desulfurized compounds is largely retained. We are evaluating the potential of commercially available enzymes to selectively catalyze oxidation at sulfur.

  1. Enzymatic desulfurization of coal

    SciTech Connect

    Boyer, Y.N.; Crooker, S.C.; Kitchell, J.P.; Nochur, S.V.

    1990-03-23

    Our experimental approach focuses on the use of enzymes which catalyze the addition of oxygen to organic compounds. In tailoring the application of these enzymes to coal processing, we are particularly interested in ensuring that oxidation occurs at sulfur and not at carbon-carbon bonds. Previous studies with DBT have shown that the reaction most frequently observed in microbial oxidative pathways is one in which DBT is oxidized at ring carbons. These reactions, as we have said, are accompanied by a considerable decrease in the energy content of the compound. In addition, microbial pathways have been identified in which the sulfur atom is sequentially oxidized to sulfoxide, to sulfone, to sulfonate, and finally to sulfuric acid. In this case, the fuel value of the desulfurized compounds is largely retained. We are evaluating the potential of commercially available enzymes to perform this function.

  2. The Biocatalytic Desulfurization Project

    SciTech Connect

    David Nunn; James Boltz; Philip M. DiGrazia; Larry Nace

    2006-03-03

    The material in this report summarizes the Diversa technical effort in development of a biocatalyst for the biodesulfurization of Petro Star diesel as well as an economic report of standalone and combined desulfurization options, prepared by Pelorus and Anvil, to support and inform the development of a commercially viable process. We will discuss goals of the projected as originally stated and their modification as guided by parallel efforts to evaluate commercialization economics and process parameters. We describe efforts to identify novel genes and hosts for the generation of an optimal biocatalyst, analysis of diesel fuels (untreated, chemically oxidized and hydrotreated) for organosulfur compound composition and directed evolution of enzymes central to the biodesulfurization pathway to optimize properties important for their use in a biocatalyst. Finally we will summarize the challenges and issues that are central to successful development of a viable biodesulfurization process.

  3. CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

    SciTech Connect

    David A. Green; Brian S. Turk; Jeffrey W. Portzer; Raghubir P. Gupta; William J. McMichael; Thomas Nelson

    2004-11-01

    Laboratory studies were conducted to investigate dry, regenerable, alkali carbonate-based sorbents for the capture of CO{sub 2} from power plant flue gas. Electrobalance, fixed-bed and fluid-bed reactors were used to examine both the CO{sub 2} capture and sorbent regeneration phases of the process. Sodium carbonate-based sorbents (calcined sodium bicarbonate and calcined trona) were the primary focus of the testing. Supported sodium carbonate and potassium carbonate sorbents were also tested. Sodium carbonate reacts with CO{sub 2} and water vapor contained in flue gas at temperatures between 60 and 80 C to form sodium bicarbonate, or an intermediate salt (Wegscheider's salt). Thermal regeneration of this sorbent produces an off-gas containing equal molar quantities of CO{sub 2} and H{sub 2}O. The low temperature range in which the carbonation reaction takes place is suited to treatment of coal-derived flue gases following wet flue gas desulfurization processes, but limits the concentration of water vapor which is an essential reactant in the carbonation reaction. Sorbent regeneration in an atmosphere of CO{sub 2} and water vapor can be carried out at a temperature of 160 C or higher. Pure CO{sub 2} suitable for use or sequestration is available after condensation of the H{sub 2}O. Flue gas contaminants such as SO{sub 2} react irreversibly with the sorbent so that upstream desulfurization will be required when sulfur-containing fossil fuels are used. Approximately 90% CO{sub 2} capture from a simulated flue gas was achieved during the early stages of fixed-bed reactor tests using a nominal carbonation temperature of 60 C. Effectively complete sorbent carbonation is possible when the fixed-bed test is carried out to completion. No decrease in sorbent activity was noted in a 15-cycle test using the above carbonation conditions coupled with regeneration in pure CO{sub 2} at 160 C. Fluidized-bed reactor tests of up to five cycles were conducted. Carbonation of sodium

  4. Carbon Dioxide Capture from Flue Gas Using Dry Regenerable Sorbents

    SciTech Connect

    David A. Green; Brian S. Turk; Jeffrey W. Portzer; Raghubir P. Gupta; William J. McMichael; Thomas Nelson; Santosh Gangwal; Ya Liang; Tyler Moore; Margaret Williams; Douglas P. Harrison

    2004-09-30

    Laboratory studies were conducted to investigate dry, regenerable, alkali carbonate-based sorbents for the capture of CO{sub 2} from power plant flue gas. Electrobalance, fixed-bed and fluid-bed reactors were used to examine both the CO{sub 2} capture and sorbent regeneration phases of the process. Sodium carbonate-based sorbents (calcined sodium bicarbonate and calcined trona) were the primary focus of the testing. Supported sodium carbonate and potassium carbonate sorbents were also tested. Sodium carbonate reacts with CO{sub 2} and water vapor contained in flue gas at temperatures between 60 and 80 C to form sodium bicarbonate, or an intermediate salt (Wegscheider's salt). Thermal regeneration of this sorbent produces an off-gas containing equal molar quantities of CO{sub 2} and H{sub 2}O. The low temperature range in which the carbonation reaction takes place is suited to treatment of coal-derived flue gases following wet flue gas desulfurization processes, but limits the concentration of water vapor which is an essential reactant in the carbonation reaction. Sorbent regeneration in an atmosphere of CO{sub 2} and water vapor can be carried out at a temperature of 160 C or higher. Pure CO{sub 2} suitable for use or sequestration is available after condensation of the H{sub 2}O. Flue gas contaminants such as SO{sub 2} react irreversibly with the sorbent so that upstream desulfurization will be required when sulfur-containing fossil fuels are used. Approximately 90% CO{sub 2} capture from a simulated flue gas was achieved during the early stages of fixed-bed reactor tests using a nominal carbonation temperature of 60 C. Effectively complete sorbent carbonation is possible when the fixed-bed test is carried out to completion. No decrease in sorbent activity was noted in a 15-cycle test using the above carbonation conditions coupled with regeneration in pure CO{sub 2} at 160 C. Fluidized-bed reactor tests of up to five cycles were conducted. Carbonation of sodium

  5. Performance of Zn-Fe-Mn/MCM-48 sorbents for high temperature H2S removal and analysis of regeneration process

    NASA Astrophysics Data System (ADS)

    Huang, Z. B.; Liu, B. S.; Wang, F.; Amin, R.

    2015-10-01

    MCM-48 was synthesized using a rapid and facile process at room temperature. A series of 50%Zn-Fe-Mn/MCM-48 sorbents were prepared and their performance of hot coal gas desulfurization was investigated. High breakthrough sulfur capacity (13.2 g-S/100 g sorbent) and utilization (66.1%) of 50%1Zn2Fe2Mn/MCM-48 sorbent at 550 °C was achieved. The characterization results of XRD, BET, TPR and FT-IR revealed that MCM-48 had excellent thermal stability at less than 700 °C, ZnMn2O4 and (Mn, Zn)Fe2O4 were mainly active particles in fresh sorbents which were highly dispersed on support. The MCM-48 mesoporous structure remained intact after eight successive desulfurization/regeneration cycles. The regeneration process of 50%1Zn2Fe2Mn/MCM-48 sorbent was analyzed, it indicated that the breakthrough sulfur capacity decline of sorbent was due to the migration of Zn onto the sorbent surface and Zn accumulated on the surface and vaporized to the exterior from the surface. In the TPO test, the oxidation of Zn was different for 50%Zn/MCM-48 at 700 °C. It revealed that the temperature of regeneration for ZnO sorbent should be higher than 700 °C.

  6. Long Duration Sorbent Testbed

    NASA Technical Reports Server (NTRS)

    Howard, David F.; Knox, James C.; Long, David A.; Miller, Lee; Cmaric, Gregory; Thomas, John

    2016-01-01

    The Long Duration Sorbent Testbed (LDST) is a flight experiment demonstration designed to expose current and future candidate carbon dioxide removal system sorbents to an actual crewed space cabin environment to assess and compare sorption working capacity degradation resulting from long term operation. An analysis of sorbent materials returned to Earth after approximately one year of operation in the International Space Station's (ISS) Carbon Dioxide Removal Assembly (CDRA) indicated as much as a 70% loss of working capacity of the silica gel desiccant material at the extreme system inlet location, with a gradient of capacity loss down the bed. The primary science objective is to assess the degradation of potential sorbents for exploration class missions and ISS upgrades when operated in a true crewed space cabin environment. A secondary objective is to compare degradation of flight test to a ground test unit with contaminant dosing to determine applicability of ground testing.

  7. Molten iron oxysulfide as a superior sulfur sorbent. Final report, [September 1989--1993

    SciTech Connect

    Hepworth, M.T.

    1993-03-31

    The studies had as original objective the analysis of conditions for using liquid iron oxysulfide as a desulfuring agent during coal gasification. Ancillary was a comparison of iron oxysulfide with lime as sorbents under conditions where lime reacts with S-bearing gases to form Ca sulfate or sulfide. Primary thrust is to determine the thermodynamic requirements for desulfurization by iron additions (e.g., taconite concentrate) during combustion in gasifiers operating at high equivalence ratios. Thermodynamic analysis of lime-oxygen-sulfur system shows why lime is injected into burners under oxidizing conditions; reducing conditions forms CaS, requiring its removal, otherwise oxidation and release of S would occur. Iron as the oxysulfide liquid has a range of stability and can be used as a desulfurizing agent, if the burner/gasifier operates in a sufficiently reducing regime (high equivalence ratio); this operating range is given and is calculable for a coal composition, temperature, stoichiometry. High moisture or hydrogen contents of the coal yield a poorer degree of desulfurization. Kinetic tests on individual iron oxide particles on substrates or Pt cups with a TGA apparatus fail to predict reaction rates within a burner. Preliminary tests on the Dynamic Containment Burner with acetylene give some promise that this system can produce the proper conditions of coal gasification for use of added iron as a sulfur sorbent.

  8. Mercury removal sorbents

    DOEpatents

    Alptekin, Gokhan

    2016-03-29

    Sorbents and methods of using them for removing mercury from flue gases over a wide range of temperatures are disclosed. Sorbent materials of this invention comprise oxy- or hydroxyl-halogen (chlorides and bromides) of manganese, copper and calcium as the active phase for Hg.sup.0 oxidation, and are dispersed on a high surface porous supports. In addition to the powder activated carbons (PACs), this support material can be comprised of commercial ceramic supports such as silica (SiO.sub.2), alumina (Al.sub.2O.sub.3), zeolites and clays. The support material may also comprise of oxides of various metals such as iron, manganese, and calcium. The non-carbon sorbents of the invention can be easily injected into the flue gas and recovered in the Particulate Control Device (PCD) along with the fly ash without altering the properties of the by-product fly ash enabling its use as a cement additive. Sorbent materials of this invention effectively remove both elemental and oxidized forms of mercury from flue gases and can be used at elevated temperatures. The sorbent combines an oxidation catalyst and a sorbent in the same particle to both oxidize the mercury and then immobilize it.

  9. Production of elemental sulfur from H{sub 2}S and CO{sub 2} derived from a coal desulfurization process. Quarterly technical process report, April 1, 1994--June 30, 1994

    SciTech Connect

    Hu, Longsheng; Jiang, Xueyu; Khang, Soon-Jai

    1994-08-01

    During the third quarter of this project, by using the apparatus previously setup for preparation of catalysts, the CoO-MoO{sub 3}-Al{sub 2}O{sub 3} catalyst was prepared and the thermal stability of the catalyst was tested. Efforts were made on the calibration and the programming of the two column GC of a Perkin Elmer Gas Chromatograph. Column A was used for detecting sulfur related substances such as H{sub 2}S, COS and CS{sub 2}, and column B was for CO, CH{sub 4} and H{sub 2}. All of the GC standard curves were obtained. Non-catalytic experiments were carried out by using the packed bed reactor system with blank, filled only with quartz wool and Al{sub 2}O{sub 3} support for future reference. A modified new reactor was designed to quickly quench the reaction and to prohibit the occurrence of re-equilibration of reaction products. Further thermodynamic analyses for the reaction of H{sub 2}S and CO, were performed using the Stanjan method.

  10. ENGINEERING EVALUATION OF HOT-GAS DESULFURIZATION WITH SULFUR RECOVERY

    SciTech Connect

    G.W. ROBERTS; J.W. PORTZER; S.C. KOZUP; S.K. GANGWAL

    1998-05-31

    Engineering evaluations and economic comparisons of two hot-gas desulfurization (HGD) processes with elemental sulfur recovery, being developed by Research Triangle Institute, are presented. In the first process, known as the Direct Sulfur Recovery Process (DSRP), the SO{sub 2} tail gas from air regeneration of zinc-based HGD sorbent is catalytically reduced to elemental sulfur with high selectivity using a small slipstream of coal gas. DSRP is a highly efficient first-generation process, promising sulfur recoveries as high as 99% in a single reaction stage. In the second process, known as the Advanced Hot Gas Process (AHGP), the zinc-based HGD sorbent is modified with iron so that the iron portion of the sorbent can be regenerated using SO{sub 2} . This is followed by air regeneration to fully regenerate the sorbent and provide the required SO{sub 2} for iron regeneration. This second-generation process uses less coal gas than DSRP. Commercial embodiments of both processes were developed. Process simulations with mass and energy balances were conducted using ASPEN Plus. Results show that AHGP is a more complex process to operate and may require more labor cost than the DSRP. Also capital costs for the AHGP are higher than those for the DSRP. However, annual operating costs for the AHGP appear to be considerably less than those for the DSRP with a potential break-even point between the two processes after just 2 years of operation for an integrated gasification combined cycle (IGCC) power plant using 3 to 5 wt% sulfur coal. Thus, despite its complexity, the potential savings with the AHGP encourage further development and scaleup of this advanced process.

  11. THE BIOCATALYTIC DESULFURIZATION PROJECT

    SciTech Connect

    Steven E. Bonde; David Nunn

    2003-04-01

    Research activities in the second quarter have largely been a continuation of efforts previously described in the first quarterly report as well as a degree of redirection of effort as a result of discussions during the first quarterly meeting held in San Diego. Chemical synthesis efforts have been refined and are currently being used to support generation of substrates for evaluation and evolution of enzymes for their oxidation. Analysis of the sulfur species in Petro Star diesel, CED extract and refinement of the speciation data is nearly complete. Molecular biology efforts continue with the cloning, expression and characterization of the DszA and DszC proteins as well as the flavin reductases to support regeneration of the essential FMN cofactors. In addition, we have initiated an evolution effort for the extension and improvement of DszA enzyme activity using Diversa's Gene Site Saturation Mutagenesis (GSSM{trademark}) technology. To support the evolution effort as well as of characterization of enzyme activities on a variety of substrates, a high-throughput mass spectroscopy-based assay has been developed. Two selection/screen strategies for the discovery and evolution of biocatalyst enzyme have been developed and are being evaluated for performance using gene libraries constructed from known biodesulfurization strains and environmental libraries.

  12. Desulfurization apparatus and method

    DOEpatents

    Rong, Charles; Jiang, Rongzhong; Chu, Deryn

    2013-06-18

    A method and system for desulfurization comprising first and second metal oxides; a walled enclosure having an inlet and an exhaust for the passage of gas to be treated; the first and second metal oxide being combinable with hydrogen sulfide to produce a reaction comprising a sulfide and water; the first metal oxide forming a first layer and the second metal oxide forming a second layer within the walled surroundings; the first and second layers being positioned so the first layer removes the bulk amount of the hydrogen sulfide from the treated gas prior to passage through the second layer, and the second layer removes substantially all of the remaining hydrogen sulfide from the treated gas; the first metal oxide producing a stoichiometrical capacity in excess of 500 mg sulfur/gram; the second metal oxide reacts with the hydrogen sulfide more favorably but has a stoichometrical capacity which is less than the first reactant; whereby the optimal amount by weight of the first and second metal oxides is achieved by utilizing two to three units by weight of the first metal oxide for every unit of the second metal oxide.

  13. CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

    SciTech Connect

    David A. Green; Brian S. Turk; Jeffrey W. Portzer; Raghubir P. Gupta; William J. McMichael; Ya Liang; Douglas P. Harrison

    2003-01-01

    The objective of this project is to develop a simple and inexpensive process to separate CO{sub 2} as an essentially pure stream from a fossil fuel combustion system using a regenerable sorbent. The sorbents being investigated in this project are primarily alkali carbonates, and particularly sodium carbonate and potassium carbonate, which are converted to bicarbonates or intermediate salts through reaction with carbon dioxide and water vapor. Bicarbonates are regenerated to carbonates when heated, producing a nearly pure CO{sub 2} stream after condensation of water vapor. This quarter, electrobalance tests suggested that high calcination temperatures decrease the activity of sodium bicarbonate Grade 1 (SBC No.1) during subsequent carbonation cycles, but there is little or no progressive decrease in activity in successive cycles. SBC No.1 appears to be more active than SBC No.3. As expected, the presence of SO{sub 2} in simulated flue gas results in a progressive loss of sorbent capacity with increasing cycles. This is most likely due to an irreversible reaction to produce Na{sub 2}SO{sub 3}. This compound appears to be stable at calcination temperatures as high as 200 C. Tests of 40% supported potassium carbonate sorbent and plain support material suggest that some of the activity observed in tests of the supported sorbent may be due to adsorption by the support material rather than to carbonation of the sorbent.

  14. Production of elemental sulfur from H{sub 2}S and CO{sub 2} derived from a coal desulfurization process. Quarterly technical process report, December 1, 1993--March 31, 1994

    SciTech Connect

    Hu, L.; Jiang, X.; Khang, S.J.

    1994-05-01

    During the second quarter of the project, an experimental apparatus was setup for catalyst screening studies. Sulfided Co-Mo-Al{sub 2}O{sub 3} catalyst was prepared and a thermodynamic study for the reaction of H{sub 2}S and CO{sub 2} was performed. A packed bed reactor made of quartz tube was setup for catalyst screening studies. This reactor was also used for the H{sub 2} reduction of catalyst. Temperature profile in the reactor was measured and results indicated that in the middle of the reactor (5 to 6 inches in length) the temperature profile may be regarded as isothermal. Sulfided Co-Mo catalyst was prepared by first reducing (using H{sub 2}) and sulfiding (using H{sub 2}S) a commercially available CoO-MoO{sub 3}-Al{sub 2}O{sub 3} catalyst. Thermodynamic analysis for the reaction of H{sub 2}S and CO{sub 2} was performed by using the JANAF thermochemic table and the STANJAN method. The results indicated that the following reaction mechanism might be suitable for the reaction of H{sub 2}S and CO{sub 2} to produce elemental sulfur and methane: (1) 2H{sub 2}S = 2H{sub 2}+S{sub 2}, (2) CO{sub 2}+H{sub 2}=CO+H{sub 2}O, (3) CO{sub 2}+4H{sub 2}=CH{sub 4}+2H{sub 2}O, and (4) CO+3H{sub 2}=CH{sub 4}+2H{sub 2}O.

  15. Anion-exchange resin-based desulfurization process. Annual technical progress report, October 1, 1992--September 30, 1993

    SciTech Connect

    Sheth, A.C.; Dharmapurikar, R.; Strevel, S.D.

    1993-11-01

    Under the DOE Grant No. DE-FG22-90PC90309, the University of Tennessee Space Institute (UTSI) has been directed to further develop an anion-exchange, resin-based desulfurization concept that has been developed and tested on a limited scope for feasibility. From environmental as well as the economic viewpoints, it is necessary that the soluble sulfates of alkali metal sorbents be desulfurized (regenerated) and recycled to make regenerative flue gas desulfurization and MHD spent seed regeneration options more attractive. In order to achieve this, a low-temperature, low-cost desulfurization process to reactivate spent alkali metal sorbents is necessary. UTSI`s anion-exchange, resin-based concept uses the available technology and is believed to satisfy this requirement. In this DOE-sponsored project, UTSI, will perform the following investigations: Screening of commercially available resins; process variables study and improving resin performance; optimization of resin-regeneration step; evaluation of performance enhancers; development of Best-Process Schematic and related economics, and planning for proof-of-concept (POC) scale testing. The above activities have been grouped into five major tasks and the entire project is expected to take thirty-six months to complete.

  16. Status of METC investigations of coal gas desulfurization at high temperature. [Zinc ferrite

    SciTech Connect

    Steinfeld, G.

    1984-03-01

    This report documents the continuing effort at the US Department of Energy/Morgantown Energy Technology Center (METC) to develop a hot-gas desulfurization process for coal-derived gas, primarily for application to molten carbonate fuel cells. Metal oxide sorbents were tested on lab-scale test equipment, and it was determined that scale-up of the process was warranted. A larger, skid-mounted test unit was therefore designed, constructed, and installed on a sidestream of the DOE/METC fixed-bed gasifier. A first series of tests was conducted during Gasifier Run 101. These tests served to shake down the test unit, and provide data on the performance of the test unit operating on coal-derived gas. Overall, the process operated well on fixed-bed, air-blown gasifier gas. Sulfur levels in exit dry gas were reduced to less than 10 ppM. Regeneration appears to restore the sulfur-removing capacity of the sorbent. Sorbent integrity was maintained during the test period, which incorporated three sulfidations. It is recommended that treatment of the regeneration offgas be investigated, and that testing and development of a system to reduce the sulfur in this gas to elemental sulfur be initiated. In addition, it is suggested that a multiple reactor system be planned for continuous operation, to allow for long-term tests of downstream users of desulfurized gas. 7 references, 18 figures, 9 tables.

  17. Technical description of parameters influencing the pH value of suspension absorbent used in flue gas desulfurization systems.

    PubMed

    Głomba, Michał

    2010-08-01

    As a result of the large limestone deposits available in Poland, the low cost of reagent acquisition for the largescale technological use and relatively well-documented processes of flue gas desulfurization (FGD) technologies based on limestone sorbent slurry, wet scrubbing desulfurization is a method of choice in Poland for flue gas treatment in energy production facilities, including power plants and industrial systems. The efficiency of FGD using the above method depends on several technological and kinetic parameters, particularly on the pH value of the sorbent (i.e., ground limestone suspended in water). Consequently, many studies in Poland and abroad address the impact of various parameters on the pH value of the sorbent suspension, such as the average diameter of sorbent particles (related to the limestone pulverization degree), sorbent quality (in terms of pure calcium carbonate [CaCO3] content of the sorbent material), stoichiometric surfeit of CaCO3 in relation to sulfur dioxide (SO2) absorbed from flue gas circulating in the absorption node, time of absorption slurry retention in the absorber tank, chlorine ion concentration in sorbent slurry, and concentration of dissolved metal salts (Na, K, Mg, Fe, Al, and others). This study discusses the results of laboratory-scale tests conducted to establish the effect of the above parameters on the pH value of limestone slurry circulating in the SO2 absorption node. On the basis of the test results, a correlation equation was postulated to help maintain the desirable pH value at the design phase of the wet FGD process. The postulated equation displays good coincidence between calculated pH values and those obtained using laboratory measurements. PMID:20842941

  18. Technical description of parameters influencing the pH value of suspension absorbent used in flue gas desulfurization systems.

    PubMed

    Głomba, Michał

    2010-08-01

    As a result of the large limestone deposits available in Poland, the low cost of reagent acquisition for the largescale technological use and relatively well-documented processes of flue gas desulfurization (FGD) technologies based on limestone sorbent slurry, wet scrubbing desulfurization is a method of choice in Poland for flue gas treatment in energy production facilities, including power plants and industrial systems. The efficiency of FGD using the above method depends on several technological and kinetic parameters, particularly on the pH value of the sorbent (i.e., ground limestone suspended in water). Consequently, many studies in Poland and abroad address the impact of various parameters on the pH value of the sorbent suspension, such as the average diameter of sorbent particles (related to the limestone pulverization degree), sorbent quality (in terms of pure calcium carbonate [CaCO3] content of the sorbent material), stoichiometric surfeit of CaCO3 in relation to sulfur dioxide (SO2) absorbed from flue gas circulating in the absorption node, time of absorption slurry retention in the absorber tank, chlorine ion concentration in sorbent slurry, and concentration of dissolved metal salts (Na, K, Mg, Fe, Al, and others). This study discusses the results of laboratory-scale tests conducted to establish the effect of the above parameters on the pH value of limestone slurry circulating in the SO2 absorption node. On the basis of the test results, a correlation equation was postulated to help maintain the desirable pH value at the design phase of the wet FGD process. The postulated equation displays good coincidence between calculated pH values and those obtained using laboratory measurements.

  19. Study on a novel semidry flue gas desulfurization with multifluid alkaline spray generator

    SciTech Connect

    Zhou, Y.G.; Zhang, M.C.; Wang, D.F.; Wang, L.

    2005-11-09

    The advantages and disadvantages of the typical semidry flue gas desulfurization (FGD) processes are analyzed, and a novel semidry FGD process with multifluid alkaline spray generator is first proposed to improve the colliding contact efficiency between sorbent particles and spray water droplets, and to form a large amount of aqueous lime slurry. The experimental results show that the colliding contact efficiency between lime particles and water droplets in the prefix alkaline spray generator may reach about 70%, which is significantly higher than the colliding contact efficiency of 25% in duct sorbent injection. The SO{sub 2} removal efficiency can reach 64.5% when the Ca/S molar ratio is 1.5, the approach to the saturation temperature is 10.3{sup o}C, and the flue gas residence time is 2.25 s. It is higher than that of in-duct sorbent injection under similar conditions, and the sorbent utilization is improved to 43%. Therefore, the FGD process with a prefix alkaline spray generator can greatly improve SO{sub 2} removal efficiency and sorbent utilization and it will be a new, simple and efficient semidry FGD process for industrial application in the future.

  20. Fixed bed testing of a molybdenum-promoted zinc titanate for hot gas desulfurization

    SciTech Connect

    Gasper-Galvin, L.D.; Mei, J.S.; Everitt, C.E.; Katta, S.

    1993-09-01

    The following conclusions were made, based upon this study of T-2535 molybdenum-promoted zinc titanate: (1) Results of the half-cycle sulfidation experiments showed that sorbent efficiency and capacity of this formulation of zinc titanate were weak functions of operating-bed temperature. Evidence of diffusion limitations on the sulfidation reaction were observed, particularly at superficial velocities greater than 30 cm/s (1 ft/s). Sorbent performance appeared to be affected by the concentration of reducing gases and/or water content of the simulated coal gas mixtures. Sorbent capacity and efficiency deteriorated during the first three cycles, but stabilized thereafter. (2) Sorbent spalling was observed and appeared to increase with sulfur loading. Possible causes of spalling may be attributed to the induced crystal lattice stresses due to the formation of ZnS and especially ZnSO{sub 4}, which have relative molar volumes that are approximately 1-1/2 and 3 times larger, respectively, than that of the original ZnO. (3) Based on these results, it is apparent that the molybdenum-promoted zinc titanate with Zn/Ti molar ratio of 1.91 may not be a suitable sorbent for hot gas desulfurization in the fixed bed reactor for the Pinon Pine project, due to problems with spalling and loss of reactivity during sulfidation/regeneration cycling.

  1. Long Duration Sorbent Testbed

    NASA Technical Reports Server (NTRS)

    Knox, James; Long, David; Miller, Lee; Thomas, John; Cmarik, Greg; Howard, David

    2016-01-01

    The LDST is a flight experiment demonstration designed to expose current and future candidate carbon dioxide removal system sorbents to an actual crewed space cabin environment to assess and compare sorption working capacity degradation resulting from long term operation. An analysis of sorbent materials returned to earth after approximately one year of operation in the International Space Station's (ISS) Carbon Dioxide Removal Assembly (CDRA) indicated as much as a 70% loss of working capacity of the silica gel desiccant material at the extreme system inlet location, with a gradient of capacity loss down the bed. The primary science objective is to assess the degradation of potential sorbents for exploration class missions and ISS upgrades when operated in a true crewed space cabin environment. A secondary objective is to compare degradation of flight test to a ground test unit with contaminant dosing to determine applicability of ground testing.

  2. Space-filling polyhedral sorbents

    DOEpatents

    Haaland, Peter

    2016-06-21

    Solid sorbents, systems, and methods for pumping, storage, and purification of gases are disclosed. They derive from the dynamics of porous and free convection for specific gas/sorbent combinations and use space filling polyhedral microliths with facial aplanarities to produce sorbent arrays with interpenetrating interstitial manifolds of voids.

  3. Microbial stabilization of sulfur-laden sorbents. Final technical report, September 1, 1992--August 31, 1993

    SciTech Connect

    Miller, K.W.; Hillyer, D.

    1993-12-31

    Clean coal technologies that involve limestone for sulfur capture generate lime/limestone products laden with sulfur at various oxidation states. If sulfur is completely stabilized as sulfate, the spent sorbent is ready for commercial utilization as gypsum. However, the presence of reduced sulfur species requires additional processing. Thermal oxidation of reduced sulfur can result in undesirable release of SO{sub 2}. Microbial oxidation might provide an inexpensive and effective alternative. Sorbents laden with reduced forms of sulfur such as sulfide or sulfite can serve as growth substrates for sulfur-oxidizing bacteria, which convert all sulfur to sulfate. The goals of this project are the following: (1) to optimize conditions for sulfate generation from sulfide, thiosulfate, and sulfite; (2) to test and optimize the effectiveness of microbial processing on spent sorbents from flue gas desulfurization, coal gasification, and fluidized bed combustion; (3) to search for hyperalkalinophilic thiobacilli, which would be effective up to pH 11.

  4. THE BIOCATALYTIC DESULFURIZATION PROJECT

    SciTech Connect

    Scott Collins; David Nunn

    2003-10-01

    The analysis of Petro Star diesel sulfur species is complete and a report is attached. Further analytical efforts will concentrate on characterization of diesel fuel, hydrodesulfurized to varying degrees, in order to determine sulfur species that may be problematic to hydrogen treatment and represent potential target substrates for biodesulfurization in a combined HDS-BDS process. Quotes have been received and are being considered for the partial treatment of Petro Star Inc. marine diesel fuel. Direction of research is changing slightly; economic analysis of the hyphenated--BDSHDS, BDS-CED--has shown the highest probability of success to be with a BDS-HDS process where the biodesulfurization precedes hydrodesulfurization. Thus, the microorganisms will be tailored to focus on those compounds that tend to be recalcitrant to hydrodesulfurization and decrease the severity of the hydrodesulfurization step. A separate, detailed justification for this change is being prepared. Research activities have continued in the characterization of the desulfurization enzymes from multiple sources. Genes for all DszA, -B, -C and -D enzymes (and homologs) have been cloned and expressed. Activity determinations, on a variety of substituted benzothiophene and dibenzothiophene substrates, have been carried out and continue. In addition, chemical synthesis efforts have been carried out to generate additional substrates for analytical standards and activity determinations. The generation of a GSSM mutant library of the ''Rhodococcus IGTS8 dszA'' gene has been completed and development of protocols for a high throughput screen to expand substrate specificity are nearing completion. In an effort to obtain improved hosts as biocatalyst, one hundred-thirty ''Rhodococcus'' and related strains are being evaluated for growth characteristics and other criteria deemed important for an optimal biocatalyst strain. We have also begun an effort to generate derivatives of the entire IGTS8 BDS plasmid

  5. Long-term testing of the zinc titanate for desulfurization of hot coal gas in a fluidized-bed reactor

    SciTech Connect

    Jain, S.C.; Gupta, R.; Gangwal, S.K.

    1993-12-31

    Research Triangle Institute (RTI) under contract to the US Department of Energy (DOE), Morgantown energy Technology Center has recently completed a long-term test consisting of 100 sulfidation-regeneration cycles on a zinc titanate material intended for use as a high-temperature, regenerable sorbent to desulfurize coal-derived gas. The primary motivation for this development is to generate a more economical, environmentally superior, and reliable process to purify the product gas of coal gasifiers for use in gas turbines and fuel cells. This zinc titanate formulation (designated as ZT-4 and containing Zn-to-Ti in a molar ratio of 1.5) exhibited the best overall performance in terms of chemical reactivity, sulfur capacity, regenerability, structural properties and, most importantly, the attrition resistance based on multicycle testing of a number of sorbent formulations in a bench scale fluidized-bed reactor. The conditions in the test were -- desulfurization temperature: 750C (1382F); pressure: 1.52 MPa (220 psia); coal gas: simulated Texaco entrained-bed oxygen-blown gasifier gas containing 12,000 ppmv of H{sub 2}S; superficial gas velocity: 15 cm/s (0.49 ft/s). The ZT-4 sorbent used in this test was prepared using a granulation technique and 500 g of the sorbent in the 100 to 300 microns particle diameter range were used in a 5.1-cm (2-inch) i.d. stainless steel reactor.

  6. Inorganic ion sorbent method

    DOEpatents

    Teter, David M.; Brady, Patrick V.; Krumhansl, James L.

    2007-07-17

    A process and medium for decontamination of water containing anionic species including arsenic and chromium, wherein compounds comprising divalent and trivalent metal oxides and sulfides are used to form surface complexes with contaminants under pH conditions within the range of potable water. In one embodiment natural and synthetic spinels and spinel-like materials are used as the sorbent substance.

  7. Inorganic ion sorbents

    DOEpatents

    Teter, David M.; Brady, Patrick V.; Krumhansl, James L.

    2006-10-17

    A process and medium for decontamination of water containing anionic species including arsenic and chromium, wherein compounds comprising divalent and trivalent metal oxides and sulfides are used to form surface complexes with contaminants under pH conditions within the range of potable water. In one embodiment natural and synthetic spinels and spinel-like materials are used as the sorbent substance.

  8. Handling, transport and dispersion of sorbent powder for in-furnace injection. Final report, September 1, 1993--August 31, 1994

    SciTech Connect

    Fan, L.S.; Abou-Zeida, E.; Liang, S.C.; Luo, Xukun

    1995-02-01

    The focus of this project is on sorbent injection technologies using dry, calcium-based sorbents for high-sulfur coal flue gas desulfurization. The goal is to provide research findings on handling, transport and dispersion of sorbent powder, aimed at improving SO{sub 2} (to at least 90%) removal and increasing sorbent utilization in a cost-effective fashion. The purpose of this project is to investigate the fundamental aspects of powder technology relevant to the fine sorbent powders, and to provide means of improving sorbent performance through superior dispersion and reduced dispersed particle size. This project is in two phases, Phase 1 ``Powder Characterization`` and Phase 2 ``Powder Mechanical Properties``. Phase 1 involves characterization of the sorbents in terms of their electrostatic properties. The triboelectric charging of powders are studied in detail by measuring sorbent charging as a function of material properties as well as transport conditions. A variety of sorbents are tested, including laboratory-made lignohydrates, calcite, dolomite, dolomitic hydrate and hydrated lime. The effects of transport tube material and gas properties, specifically humidity and velocity on the extent of sorbent charging are also investigated. A population balance model is developed to account for the particle size distribution for powder dispersion through gas-solid injection nozzles. The variations of the transition probability with the booster air velocities is examined. Simulation of particle size distributions under some operating conditions is conducted. Phase 2 investigates the flow properties of several calcium-based sorbents under different handling and transporting conditions. Effect of moisture content, as an important handling condition, on these properties is examined. Determined properties has been analyzed to study their effect on the transport and handling processes.

  9. Desulfurization of coal: Enhanced selectivity using phase transfer catalysts. Technical report, September 1--November 30, 1995

    SciTech Connect

    Palmer, S.R.; Hippo, E.J.

    1995-12-31

    Due to environmental problems related to the combustion of high sulfur Illinois coal, there continues to be interest in the development of viable pre-combustion desulfurization processes. Recent studies by the authors have obtained very good sulfur removals but the reagents that are used are too expensive. Use of cheaper reagents leads to a loss of desired coal properties. This study investigates the application of phase transfer catalysts to the selective oxidation of sulfur in coal using air and oxygen as oxidants. The phase transfer catalyst is expected to function as a selectivity moderator by permitting the use of milder reaction conditions than otherwise necessary. This would enhance the sulfur selectivity and help retain the heating value of the coal. The use of certain coal combustion wastes for desulfurization, and the application of cerium (IV) catalyzed air oxidations for selective sulfur oxidation are also being studied. If successful this project could lead to the rapid development of a commercially viable desulfurization process. This would significantly improve the marketability of Illinois coal. During this quarter aliquots of the IBC-101 coal have been ground to various particle sizes in an attempt to find the optimum physical pretreatment for mineral, especially pyrite, removal. Analysis of these various aliquots shows them to be representative of the original coal. In addition, preliminary desulfurization reactions using fly ash and scrubber sludges have been performed on an unoxidized IBC-101 sample. Results will be available next quarter. Also, SEM-EDAX analysis of the fly ash indicates that it contains oxides that have shown activity in base desulfurization reactions.

  10. CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

    SciTech Connect

    David A. Green; Brian S. Turk; Raghubir P. Gupta; William J. McMichael; Douglas P. Harrison; Ya Liang

    2002-01-01

    The objective of this project is to develop a simple, inexpensive process to separate CO{sub 2} as an essentially pure stream from a fossil fuel combustion system using a regenerable, sodium-based sorbent. The sorbent being used in this project is sodium carbonate which is converted to sodium bicarbonate, or ''baking soda,'' through reaction with carbon dioxide and water vapor. Sodium bicarbonate is regenerated to sodium carbonate when heated, producing a nearly pure CO{sub 2} stream after condensation of water vapor. This quarter, five cycle thermogravimetric tests were conducted at the Louisiana State University (LSU) with sodium bicarbonate Grade 3 (SBC{number_sign}3) which showed that carbonation activity declined slightly over 5 cycles following severe calcination conditions of 200 C in pure CO{sub 2}. Three different sets of calcination conditions were tested. Initial carbonation activity (as measured by extent of reaction in the first 25 minutes) was greatest subsequent to calcination at 120 C in He, slightly less subsequent to calcination in 80% CO{sub 2}/20% H{sub 2}O, and lowest subsequent to calcination in pure CO{sub 2} at 200 C. Differences in the extent of reaction after 150 minutes of carbonation, subsequent to calcination under the same conditions followed the same trend but were less significant. The differences between fractional carbonation under the three calcination conditions declined with increasing cycles. A preliminary fixed bed reactor test was also conducted at LSU. Following calcination, the sorbent removed approximately 19% of the CO{sub 2} in the simulated flue gas. CO{sub 2} evolved during subsequent calcination was consistent with an extent of carbonation of approximately 49%. Following successful testing of SBC{number_sign}3 sorbent at RTI reported in the last quarter, a two cycle fluidized bed reactor test was conducted with trona as the sorbent precursor, which was calcined to sodium carbonate. In the first carbonation cycle, CO

  11. Coal desulfurization by aqueous chlorination

    NASA Technical Reports Server (NTRS)

    Kalvinskas, J. J.; Vasilakos, N.; Corcoran, W. H.; Grohmann, K.; Rohatgi, N. K. (Inventor)

    1982-01-01

    A method of desulfurizing coal is described in which chlorine gas is bubbled through an aqueous slurry of coal at low temperature below 130 degrees C., and at ambient pressure. Chlorinolysis converts both inorganic and organic sulfur components of coal into water soluble compounds which enter the aqueous suspending media. The media is separated after chlorinolysis and the coal dechlorinated at a temperature of from 300 C to 500 C to form a non-caking, low-sulfur coal product.

  12. Modified clay sorbents

    DOEpatents

    Fogler, H. Scott; Srinivasan, Keeran R.

    1990-01-01

    A novel modified clay sorbent and method of treating industrial effluents to remove trace pollutants, such as dioxins, biphenyls, and polyaromatics such as benzo(a)pyrene and pentachlorophenol. The novel clay sorbent has a composite structure in which the interlayer space of an expandable clay, such as smectite, is filled with polyvalent or multivalent inorganic cations which forces weaker surfactant cations to locate on the surface of the clay in such an orientation that the resulting composite is hydrophilic in nature. A specific example is cetylpyridinium-hydroxy aluminum-montmorillonite. In certain embodiments, a non-expanding clay, such as kaolinite, is used and surfactant cations are necessarily located on an external surface of the clay. A specific example is cetylpyridinium-kaolinite.

  13. ADVANCED SORBENT DEVELOPMENT PROGRAM

    SciTech Connect

    Unknown

    1998-06-16

    The overall objective of this program was to develop regenerable sorbents for use in the temperature range of 343 to 538 C (650 to 1000 F) to remove hydrogen sulfide (H{sub 2}S) from coal-derived fuel gases in a fluidized-bed reactor. The goal was to develop sorbents that are capable of reducing the H{sub 2}S level in the fuel gas to less than 20 ppmv in the specified temperature range and pressures in the range of 1 to 20 atmospheres, with chemical characteristics that permit cyclic regeneration over many cycles without a drastic loss of activity, as well as physical characteristics that are compatible with the fluidized bed application.

  14. Numerical simulation of multiphase flow and collision humidification in the multifluid alkaline spray generator for a novel semidry flue gas desulfurization system

    SciTech Connect

    Zhou, Y.G.; Cao, W.C.; Wang, L.; Zhang, M.C.

    2008-07-15

    A hybrid Eulerian-Lagrangian model was developed to simulate gas-droplet-particle multiphase flow and the collision humidification between sorbent particles and spray droplets in the confined multifluid alkaline spray generator for a novel semidry flue gas desulfurization system. In this model, the motions of discrete phases were tracked simultaneously by using a stochastic trajectory approach, and a probability model of droplets catching particles was presented to judge whether sorbent particles were caught with direct simulation Monte Carlo method. Numerical humidification efficiency of sorbent particles is validated by the experimental one deduced from the measured desulfurization efficiency. The effects of flue gas flow rate, spray droplet diameter, sorbent particle diameter, and particle injection location on the humidification efficiency were optimized. Numerical results show that the collision humidification efficiency of sorbent particles increases significantly at the axial distance of 1.67 times the generator diameter from the nozzle tip and reaches 78.5% without recirculation flow in the alkaline spray generator when the ratio of flue gas mass flow rate to spray water mass flow rate is 6.7. Moreover, there is an optimal droplet diameter ranging from 125 to 150 {mu} m and an optimal particle injection location corresponding to the maximum humidification efficiency in this paper.

  15. Global evaluation of mass transfer effects: In-duct injection flue gas desulfurization

    SciTech Connect

    Cole, J.A.; Newton, G.H.; Kramlich, J.C.; Payne, R.

    1990-09-30

    Sorbent injection is a low capital cost, low operating cost approach to SO{sub 2} control targeted primarily at older boilers for which conventional fuel gas desulfurization is not economically viable. Duct injection is one variation of this concept in which the sorbent, either a dry powder or a slurry, is injected into the cooler regions of the boiler, generally downstream of the air heaters. The attractiveness of duct injection is tied to the fact that it avoids much of the boiler heat transfer equipment and thus has minimal impact of boiler performance. Both capital and operating cost are low. This program has as its objectives three performance related issues to address: (1) experimentally identify limits on sorbent performance. (2) identify and test sorbent performance enhancement strategies. (3) develop a compute model of the duct injection process. Two major tasks are described: a laboratory-scale global experiment and development of process model. Both are aimed at understanding and quantifying the rate-limiting processes which control SO{sub 2} capture by lime slurry during boiler duct injection. 29 refs., 35 figs., 4 tabs.

  16. Investigation on durability and reactivity of promising metal oxide sorbents during sulifidation and regeneration: Technical progress report for July 1--September 30, 1996

    SciTech Connect

    Kwon, K.C.

    1996-11-01

    The main objectives of this research project during this quarter are to formulate metal oxide sorbents using various ingredients as well as formulation conditions, and test reactivity of formulated metal oxide sorbents with hydrogen sulfide for 120 seconds at 550{degrees}C, and develop a formula of a sorbent suitable for the removal of hydrogen sulfide from hot coal gases. Metal oxide sorbents were formulated with zinc oxide as an active sorbent ingredient, and titanium oxide as a supporting metal oxide. Various additives such as Al, Ce, Zr, Cu, Co, Ni, Mn, Cr and Ca were utilized to enhance sulfur-removal capacity of formulated metal oxide sorbents. The additives Cu and Co appear to enhance reactivity of sorbents in the reaction with wet hot hydrogen sulfide at 550{degrees}C. Durability of formulated sorbents appears to improve with kaolin binder in comparison with bentonite binder. Durability of formulated sorbents appears to improve with increased calcination durations. Reactivity of sorbents formulated with Co additive appears to decrease with increased calcination durations at the calcination temperature of 860{degrees}C. Reactivity of sorbents formulated with Cu additive appears to increase with calcination durations. Reactivity of sorbents formulated without additive appears to be independent of calcination durations.

  17. A regenerable sorbent injection/filtration process for H{sub 2}S removal from hot gas

    SciTech Connect

    Higgins, R.J.; Ji, W.; Connors, M.J.; Jones, J.F.; Goldsmith, R.L.

    1996-12-31

    The operational characteristics of a hot gas desulfurization process involving regenerable sorbent injection and its subsequent collection with a ceramic filtration device were studied utilizing a bench-scale transport reactor. Hydrogen sulfide removal from simulated hot gas was evaluated as a function of both zinc oxide-based sorbent physical and chemical characteristics and various process parameters. In addition, the sorbent capture efficiency and regenerability of the ceramic filtration device were evaluated, and regeneration of sulfided sorbents via injection into an oxidizing gas was studied. For both sorbent sulfidation and spent sorbent regeneration, gas-solid reaction occurred both in the duct and within layers of partially reacted sorbent captured by the ceramic filter. Very high sulfur removal efficiencies were obtained only in highly reducing hot gas compositions at or above about 700 C, using stoichiometric ratio (defined as ZnO/H{sub 2}S ratio) values of about 1.5, and sorbent particles of about 20 {micro}m or less in diameter. Under such conditions, the experimental data indicated that reaction of H{sub 2}S with zinc vapor formed by reduction of zinc oxide contributed appreciably to sulfur removal. Negligible zinc loss from the hot zone of the reactor was detected, apparently due to rapid formation of zinc sulfide product layers on zinc oxide particles. The ceramic filtration devices captured 100% of all sorbent particles and were fully regenerable over periods of several tens of injection/backpulse cleaning cycles. Spent sorbent could be fully regenerated rapidly at 850 C without problems due to exotherm generation.

  18. Low temperature aqueous desulfurization of coal

    DOEpatents

    Slegeir, W.A.; Healy, F.E.; Sapienza, R.S.

    1985-04-18

    This invention describes a chemical process for desulfurizing coal, especially adaptable to the treatment of coal-water slurries, at temperatures as low as ambient, comprising treating the coal with aqueous titanous chloride whereby hydrogen sulfide is liberated and the desulfurized coal is separated with the conversion of titanous chloride to titanium oxides.

  19. Low temperature aqueous desulfurization of coal

    DOEpatents

    Slegeir, William A.; Healy, Francis E.; Sapienza, Richard S.

    1985-01-01

    This invention describes a chemical process for desulfurizing coal, especially adaptable to the treatment of coal-water slurries, at temperatures as low as ambient, comprising treating the coal with aqueous titanous chloride whereby hydrogen sulfide is liberated and the desulfurized coal is separated with the conversion of titanous chloride to titanium oxides.

  20. Bench-Scale Testing of Attrition Resistant Moving Bed Sorbents

    SciTech Connect

    Swisher, J.H.; Gupta, R.P.

    1996-12-31

    Integrated Gasification Combined Cycle (IGCC) systems with cold-gas cleanup have now reached the early stages of commercialization. The foundation for this was successful completion of the Cool Water Coal Gasification Program several years ago. Destec Energy, Inc., a subsidiary of Dow Chemical Company, has a plant in operation in Louisiana, and the 2 Wabash River Plant in Indiana is now starting up. A similar plant based on the Shell gasification technology is operating in the Netherlands. In two new plants now under construction, the Tampa Electric Plant in Florida and the Sierra Pacific Power Plant in Nevada, incorporating hot-gas cleanup technology is desirable. Unfortunately, some nagging problems remain with both sulfur sorbent and particle filter technology that may result in the use of cold-gas, rather than hot-gas, cleanup in these plants. With sulfur sorbents, the main problems are with mechanical property degradation and/or loss of sulfur capacity over many sulfidation-regeneration cycles. The sorbents receiving the most attention are all zinc based. They include various zinc titanate formulations and proprietary materials developed by the U.S. Department of Energy/Morgantown Energy Technology Center (DOE/METC) staff and the Phillips Petroleum Company. The investigators on this project are now completing their third year of effort on a superstrong zinc titanate sorbent. Prior to this year, various formulations were prepared and evaluated for their potential use in fixed- and fluidized-bed hot-gas desulfurization systems. A unique feature, the reason for the high strength, is that the zinc titanate is contained in a matrix of titanium dioxide. Its crush strength is more than 6 times that prior investigators achieved.

  1. Engineered sorbent barrier screening studies

    SciTech Connect

    Freeman, H.D.; Buelt, J.L.

    1985-08-01

    The objective of the Engineered Sorbent Barrier Program is to identify new and cost-effective technology for restricting the migration of radionuclides from low-level waste sites. The primary emphasis is to identify and evaluate sorbent materials as engineered barriers that will prevent radionuclide migration and yet allow moisture to pass. Screening studies have been completed to identify sorbent materials for cesium, cobalt, and strontium. The sorbent materials were selected based on criteria developed for this program and the empirical results of screening studies. The results of the study made it apparent that no single sorbent materials is effective for all radionuclides considered. Therefore, four composite sorbent barriers were identified for further evaluation in 0.6-m diameter columns. The large columns more accurately represent field conditions, generate permeability data, and enhance detectability of radionuclides in the leachate passing through the sorbent barriers. The four sorbent barriers include composites of activated charcoal, greensand, A-51 zeolite, and red pottery clay. Future studies will concentrate on completing the effectiveness evaluations with the large columns and identifying a more cost-effective sorbent material for strontium. 6 refs., 4 figs., 4 tabs.

  2. Measurement of Mercury in Flue Gas Based on an Aluminum Matrix Sorbent

    PubMed Central

    Wang, Juan; Xu, Wei; Wang, Xiaohao; Wang, Wenhua

    2011-01-01

    The measurement of total mercury in flue gas based on an economical aluminum matrix sorbent was developed in this paper. A sorbent trap consisted of three tubes was employed to capture Hg from flue gas. Hg trapped on sorbent was transferred into solution by acid leaching and then detected by CVAAS. Hg adsorbed on sorbent was recovered completely by leaching process. The 87.7% recovery of Hg in flue gas by tube 1 and tube 2 was obtained on the equipment of coal combustion and sampling in lab. In order to evaluate the ability to recover and accurately quantify Hg0 on the sorbent media, the analytical bias test on tube 3 spiked with Hg0 was also performed and got the average recovery of 97.1%. Mercury measurements based on this method were conducted for three coal-fired power plants in China. The mercury in coal is distributed into bottom ash, electrostatic precipitator (ESP) ash, wet flue gas desulfurization (WFGD) reactant, and flue gas, and the relative distribution varied depending on factors such as the coal type and the operation conditions of plants. The mercury mass balances of three plants were also calculated which were 91.6%, 77.1%, and 118%, respectively. The reliability of this method was verified by the Ontario Hydro (OH) method either in lab or in field. PMID:22235178

  3. INVESTIGATION OF MIXED METAL SORBENT/CATALYSTS FOR THE SIMULTANEOUS REMOVAL OF SULFUR AND NITROGEN OXIDES

    SciTech Connect

    Ates Akyurtlu; Jale F. Akyurtle

    2001-08-01

    Simultaneous removal of SO{sub 2} and NO{sub x} using a regenerable solid sorbent will constitute an important improvement over the use of separate processes for the removal of these two pollutants from stack gases and possibly eliminate several shortcomings of the individual SO{sub 2} and NO{sub x} removal operations. The work done at PETC and the DOE-funded investigation of the investigators on the sulfation and regeneration of alumina-supported cerium oxide sorbents have shown that they can perform well at relatively high temperatures (823-900 K) as regenerable desulfurization sorbents. Survey of the recent literature shows that addition of copper oxide to ceria lowers the sulfation temperature of ceria down to 773 K, sulfated ceria-based sorbents can function as selective SCR catalysts even at elevated temperatures, SO{sub 2} can be directly reduced to sulfur by CO on CuO-ceria catalysts, and ceria-based catalysts may have a potential for selective catalytic reduction of NO{sub x} by methane. These observations indicate a possibility of developing a ceria-based sorbent/catalyst which can remove both SO{sub 2} and NO{sub x} from flue gases within a relatively wide temperature window, produce significant amounts of elemental sulfur during regeneration, and use methane for the selective catalytic reduction of NO{sub x}.

  4. Measurement of mercury in flue gas based on an aluminum matrix sorbent.

    PubMed

    Wang, Juan; Xu, Wei; Wang, Xiaohao; Wang, Wenhua

    2011-01-01

    The measurement of total mercury in flue gas based on an economical aluminum matrix sorbent was developed in this paper. A sorbent trap consisted of three tubes was employed to capture Hg from flue gas. Hg trapped on sorbent was transferred into solution by acid leaching and then detected by CVAAS. Hg adsorbed on sorbent was recovered completely by leaching process. The 87.7% recovery of Hg in flue gas by tube 1 and tube 2 was obtained on the equipment of coal combustion and sampling in lab. In order to evaluate the ability to recover and accurately quantify Hg(0) on the sorbent media, the analytical bias test on tube 3 spiked with Hg(0) was also performed and got the average recovery of 97.1%. Mercury measurements based on this method were conducted for three coal-fired power plants in China. The mercury in coal is distributed into bottom ash, electrostatic precipitator (ESP) ash, wet flue gas desulfurization (WFGD) reactant, and flue gas, and the relative distribution varied depending on factors such as the coal type and the operation conditions of plants. The mercury mass balances of three plants were also calculated which were 91.6%, 77.1%, and 118%, respectively. The reliability of this method was verified by the Ontario Hydro (OH) method either in lab or in field. PMID:22235178

  5. Novel preparation method of macroporous lime from limestone for high-temperature desulfurization

    SciTech Connect

    Sasaoka, Eiji; Uddin, M.A.; Nojima, Shigeru

    1997-09-01

    Limestone is a very important material as a high temperature desulfurization sorbent: limestone is used for in-bed SO{sub 2} capture in fluidized bed combustors of coal and can be used in coal gasifiers for the in-bed removal of H{sub 2}S. In order to develop a highly active calcium oxide high-temperature desulfurization sorbent, macroporous calcium oxides were directly prepared from limestone. This method is composed of two steps: swelling of the limestone in the gas phase followed by drying and calcination of the swelled samples. The swelling was found when limestone was exposed to a vapor of aqueous acetic acid. The swelling of the sample resulted from an increase of calcium acetate formation in the sample. It was then converted to macroporous calcium oxides by heating the sample to 850 C. The reactivity of the macroporous calcium oxide for the removal of SO{sub 2} or H{sub 2}S under coexisting H{sub 2}O vapor was higher than that of the calcined raw limestone. In particular, its SO{sub 2} removal capacity and oxidative character of CaS to CaSO{sub 4} and CaO were greatly improved by the swelling method.

  6. Sorbents for mercury removal from flue gas

    SciTech Connect

    Granite, Evan J.; Hargis, Richard A.; Pennline, Henry W.

    1998-01-01

    A review of the various promoters and sorbents examined for the removal of mercury from flue gas is presented. Commercial sorbent processes are described along with the chemistry of the various sorbent-mercury interactions. Novel sorbents for removing mercury from flue gas are suggested. Since activated carbons are expensive, alternate sorbents and/or improved activated carbons are needed. Because of their lower cost, sorbent development work can focus on base metal oxides and halides. Additionally, the long-term sequestration of the mercury on the sorbent needs to be addressed. Contacting methods between the flue gas and the sorbent also merit investigation.

  7. Effects of magnetic fields on improving mass transfer in flue gas desulfurization using a fluidized bed

    NASA Astrophysics Data System (ADS)

    Zhang, Qi; Gui, Keting; Wang, Xiaobo

    2016-02-01

    The effects of magnetic fields on improving the mass transfer in flue gas desulfurization using a fluidized bed are investigated in the paper. In this research, the magnetically fluidized bed (MFB) is used as the reactor in which ferromagnetic particles are fluidized with simulated flue gas under the influence of an external magnetic field. Lime slurry is continuously sprayed into the reactor. As a consequence, the desulfurization reaction and the slurry drying process take place simultaneously in the MFB. In this paper, the effects of ferromagnetic particles and external magnetic fields on the desulphurization efficiency are studied and compared with that of quartz particles as the fluidized particles. Experimental results show that the ferromagnetic particles not only act as a platform for lime slurry to precipitate on like quartz particles, but also take part in the desulfurization reaction. The results also show that the specific surface area of ferromagnetic particles after reaction is enlarged as the magnetic intensity increases, and the external magnetic field promotes the oxidation of S(IV), improving the mass transfer between sulphur and its sorbent. Hence, the efficiency of desulphurization under the effects of external magnetic fields is higher than that in general fluidized beds.

  8. Evaluation of Sorbent Injection for Mercury Control

    SciTech Connect

    Sharon Sjostrom

    2004-10-29

    The power industry in the U.S. is faced with meeting new regulations to reduce the emissions of mercury compounds from coal-fired plants. These regulations are directed at the existing fleet of nearly 1,100 boilers. These plants are relatively old with an average age of over 40 years. Although most of these units are capable of operating for many additional years, there is a desire to minimize large capital expenditures because of the reduced (and unknown) remaining life of the plant to amortize the project. Injecting a sorbent such as powdered activated carbon into the flue gas represents one of the simplest and most mature approaches to controlling mercury emissions from coal-fired boilers. The overall objective of the test program described in this quarterly report is to evaluate the capabilities of activated carbon injection at four plants with configurations that together represent 78% of the existing coal-fired generation plants. This technology was successfully evaluated in NETL's Phase I tests at scales up to 150 MW, on plants burning subbituminous and bituminous coals and with ESPs and fabric filters. The tests also identified issues that still need to be addressed, such as evaluating performance on other configurations, optimizing sorbent usage (costs), and gathering longer-term operating data to address concerns about the impact of activated carbon on plant equipment and operations. The four sites identified for testing are Sunflower Electric's Holcomb Station, AmerenUE's Meramec Station, AEP's Conesville Station, and a site burning a blend of bituminous and subbituminous coals with a cold-side ESP. This is the fourth quarterly report for this project. Long-term testing was completed at Holcomb during this reporting period and baseline testing at Meramec was begun. Preliminary results from long-term testing at Holcomb are included in this report. Planning information for the other three sites is also included. In general, quarterly reports will be used

  9. Evaluation of Sorbent Injection for Mercury Control

    SciTech Connect

    Sharon Sjostrom

    2005-02-02

    The power industry in the U.S. is faced with meeting new regulations to reduce the emissions of mercury compounds from coal-fired plants. These regulations are directed at the existing fleet of nearly 1,100 boilers. These plants are relatively old with an average age of over 40 years. Although most of these units are capable of operating for many additional years, there is a desire to minimize large capital expenditures because of the reduced (and unknown) remaining life of the plant to amortize the project. Injecting a sorbent such as powdered activated carbon into the flue gas represents one of the simplest and most mature approaches to controlling mercury emissions from coal-fired boilers. The overall objective of the test program described in this quarterly report is to evaluate the capabilities of activated carbon injection at five plants with configurations that together represent 78% of the existing coal-fired generation plants. This technology was successfully evaluated in NETL's Phase I tests at scales up to 150 MW, on plants burning subbituminous and bituminous coals and with ESPs and fabric filters. The tests also identified issues that still need to be addressed, such as evaluating performance on other configurations, optimizing sorbent usage (costs), and gathering longer-term operating data to address concerns about the impact of activated carbon on plant equipment and operations. The four sites identified for testing are Sunflower Electric's Holcomb Station, AmerenUE's Meramec Station, AEP's Conesville Station, and Detroit Edison's Monroe Power Plant. In addition to tests identified for the four main sites, parametric testing at Missouri Basin Power Project's Laramie River Station Unit 3 has been scheduled and made possible through additional costshare participation targeted by team members specifically for tests at Holcomb or a similar plant. This is the fifth quarterly report for this project. Long-term testing was completed at Meramec during this

  10. FURNACE INJECTION OF ALKALINE SORBENTS FOR SULFURIC ACID CONTROL

    SciTech Connect

    Gary M. Blythe

    2000-12-01

    This document summarizes progress on the Cooperative Agreement DE-FC26-99FT40718, Furnace Injection of Alkaline Sorbents for Sulfuric Acid Control, during the time period April 1, 2000 through September 30, 2000. The objective of this project is to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. The coincident removal of hydrochloric acid and hydrofluoric acid will also be determined, as will the removal of arsenic, a known poison for NOX selective catalytic reduction (SCR) catalysts. EPRI, the Tennessee Valley Authority (TVA), First Energy Corporation, and the Dravo Lime Company are project co-funders. URS Corporation is the prime contractor. This is the second reporting period for the subject Cooperative Agreement. During this period, the first of four short-term sorbent injection tests were conducted at the First Energy Bruce Mansfield Plant. This test determined the effectiveness of dolomite injection through out-of-service burners as a means of controlling sulfuric acid emissions from this unit. The tests showed that dolomite injection could achieve up to 95% sulfuric acid removal. Balance of plant impacts on furnace slagging and fouling, air heater fouling, ash loss-on-ignition, and the flue gas desulfurization system were also determined. These results are presented and discussed in this report.

  11. A NOVEL VAPOR-PHASE PROCESS FOR DEEP DESULFURIZATION OF NAPHTHA/DIESEL

    SciTech Connect

    B.S. Turk; R.P. Gupta; S.K. Gangwal

    2003-06-30

    Tier 2 regulations issued by the U.S. Environmental Protection Agency (EPA) require a substantial reduction in the sulfur content of gasoline. Similar regulations have been enacted for the sulfur level in on-road diesel and recently off-road diesel. The removal of this sulfur with existing and installed technology faces technical and economic challenges. These challenges created the opportunity for new emerging technologies. Research Triangle Institute (RTI) with subcontract support from Kellogg Brown & Root, Inc., (KBR) used this opportunity to develop RTI's transport reactor naphtha desulfurization (TReND) process. Starting with a simple conceptual process design and some laboratory results that showed promise, RTI initiated an accelerated research program for sorbent development, process development, and marketing and commercialization. Sorbent development has resulted in the identification of an active and attrition resistant sorbent that has been prepared in commercial equipment in 100 lb batches. Process development has demonstrated both the sulfur removal performance and regeneration potential of this sorbent. Process development has scaled up testing from small laboratory to pilot plant transport reactor testing. Testing in the transport reactor pilot plant has demonstrated the attrition resistance, selective sulfur removal activity, and regeneration activity of this sorbent material. Marketing and commercialization activities have shown with the existing information that the process has significant capital and operating cost benefits over existing and other emerging technologies. The market assessment and analysis provided valuable feedback about the testing and performance requirements for the technical development program. This market analysis also provided a list of potential candidates for hosting a demonstration unit. Although the narrow window of opportunity generated by the new sulfur regulations and the conservative nature of the refining industry

  12. Carbon Dioxide Capture from Flue Gas Using Dry Regenerable Sorbents

    SciTech Connect

    Thomas Nelson; David Green; Paul Box; Raghubir Gupta; Gennar Henningsen

    2007-06-30

    Regenerable sorbents based on sodium carbonate (Na{sub 2}CO{sub 3}) can be used to separate carbon dioxide (CO{sub 2}) from coal-fired power plant flue gas. Upon thermal regeneration and condensation of water vapor, CO{sub 2} is released in a concentrated form that is suitable for reuse or sequestration. During the research project described in this report, the technical feasibility and economic viability of a thermal-swing CO{sub 2} separation process based on dry, regenerable, carbonate sorbents was confirmed. This process was designated as RTI's Dry Carbonate Process. RTI tested the Dry Carbonate Process through various research phases including thermogravimetric analysis (TGA); bench-scale fixed-bed, bench-scale fluidized-bed, bench-scale co-current downflow reactor testing; pilot-scale entrained-bed testing; and bench-scale demonstration testing with actual coal-fired flue gas. All phases of testing showed the feasibility of the process to capture greater than 90% of the CO{sub 2} present in coal-fired flue gas. Attrition-resistant sorbents were developed, and these sorbents were found to retain their CO{sub 2} removal activity through multiple cycles of adsorption and regeneration. The sodium carbonate-based sorbents developed by RTI react with CO{sub 2} and water vapor at temperatures below 80 C to form sodium bicarbonate (NaHCO3) and/or Wegscheider's salt. This reaction is reversed at temperatures greater than 120 C to release an equimolar mixture of CO{sub 2} and water vapor. After condensation of the water, a pure CO{sub 2} stream can be obtained. TGA testing showed that the Na{sub 2}CO3 sorbents react irreversibly with sulfur dioxide (SO{sub 2}) and hydrogen chloride (HCl) (at the operating conditions for this process). Trace levels of these contaminants are expected to be present in desulfurized flue gas. The sorbents did not collect detectable quantities of mercury (Hg). A process was designed for the Na{sub 2}CO{sub 3}-based sorbent that includes a co

  13. Microbial desulfurization of natural gas

    SciTech Connect

    Sublette, K.L.; Sylvester, N.D.

    1987-01-01

    It has been demonstrated that the H/sub 2/S content of a gas can be reduced to very low levels by contact with an aerobic or anaerobic culture of Thiobacillus denitrificans if the reactor is operated under sulfide-limiting conditions. Hydrogen sulfide was observed to be an inhibitory substrate; however, upset conditions produced by excess H/sub 2/S feed were readily detected and reversed. Biomass yield is lower under aerobic conditions than anaerobic conditions presumably because of inhibition of growth by oxygen. However, under aerobic conditions the maximum loading of the biomass is 2-3 times higher than that observed for anaerobic conditions. Heterotrophic contamination was shown to have a negligible effect on reactor performance. The use of mixed cultures (T. denitrification and heterotrophs) could simplify a microbial gas desulfurization process by removing the requirement for aseptic operation of the reactor.

  14. Adsorption and desorption of sulfur dioxide on novel adsorbents for flue gas desulfurization. Final report, September 1, 1993--August 31, 1994

    SciTech Connect

    Lin, Y.S.

    1995-02-01

    Dry regenerative sorption processes have recently attracted increasing attention in flue gas desulfurization (FGD) because of their several advantages over the conventional wet-scrubbing processes. Dry sorbents are usually made by coating a transition or alkaline earth metal precursor on the surface of a porous support. Major disadvantages of these sorbents prepared by the conventional methods include relatively poor attrition resistance and low SO{sub 2} sorption capacity. The physical and especially chemical attrition (associated with the sulphation-oxidation-reduction cycles in the process) deteriorates the performance of the sorbents. The low SO{sub 2} sorption capacity is primarily due to the small surface area of the support. Materials with a high surface area are not used as the supports for FGD sorbents because these materials usually are not thermally stable at high temperatures. In the past year, the research supported by Ohio Coal Development Office was focused on synthesis and properties of sol-gel derived alumina and zeolite sorbents with improved properties for FGD. The sol-gel derived alumina has large surface area, mesopore size and excellent mechanical strength. Some alumina-free zeolites not only posses the basic properties required as a sorbent for FGD (hydrophobicity, thermal and chemical stability, mechanical strength) but also have extremely large surface area and selective surface chemistry. The major objectives of this research program were to synthesize the sol-gel derived sorbents and to explore the use of the zeolites either directly as adsorbents or as sorbent support for FGD. The research was aimed at developing novel FGD sorbents possessing better sorption equilibrium and kinetic properties and improved physical and chemical attrition resistance.

  15. Sulfidation and reduction of zinc titanate and zinc oxide sorbents for injection in gasifier exit ducts

    SciTech Connect

    Ishikawa, K. |; Krueger, C.; Flytzani-Stephanopoulos, M.; Jl, W.; Higgins, R.J.; Bishop, B.A.; Goldsmith, R.L.

    1995-12-31

    The sulfidation reaction kinetics of fine particles of zinc titanate and zinc oxide with H{sub 2}S were studied in order to test the potential of the sorbent injection hot-gas desulfurization process. Fine sorbent particles with diameter between 0.3 and 60 {mu}m were sulfided with H{sub 2}S and/or reduced with H{sub 2} in a laminar flow reactor over the temperature range of 500-900{degrees}C. Sulfidation/reduction conversion was compared for different particle sizes and sorbents with various porosities and atomic ratios of Zn and Ti. In reduction of ZnO with H{sub 2} and without H{sub 2}S, significant amount of Zn was formed and vaporized, while the presence of H{sub 2}S suppressed elemental Zn formation. This suggests that H{sub 2}S may suppress the surface reduction of ZnO and/or gaseous Zn may react with H{sub 2}S homogeneously and form fine particles of ZnS. Formation and vaporization of elemental Zn from zinc titanate sorbents was slower than from zinc oxide with and without H{sub 2}S.

  16. Recovery and recycling of limestone in LEC flue gas desulfurization. Final report, June 1, 1990--August 31, 1991

    SciTech Connect

    Gardner, N.C.; Adler, R.J.; Lin, Y.C.; Unger, M.E.; Lux, K.W.

    1992-03-01

    Prudich et al. have proposed an attractive technology called Limestone Emission Control (LEC) for removing sulfur dioxide from flue gases. Beds of 1/8 inch wet limestone particles absorb the sulfur dioxide from the gases. Sulfates and sulfites deposit on the surfaces of the particles, limiting their utilization to about 20%. The unreacted portion of the limestone can be recovered by mechanical grinding and recycling, enabling high overall sorbent utilization. Favorable economic costs derive from small equipment, simplicity, and low sorbent cost. Our research concentrates on selecting and testing on a laboratory scale suitable candidate dry and wet grinding methods for recovering limestone in LEC flue from desulfurization. A wet grinding method based on the impeller fluidizer, a new type of slurry processor, receives special attention. The impeller fluidizer is a dosed cylindrical vessel with an impeller at one end. It combines the operations of wet grinding, washing, and transporting the spent and recovered limestone as an aqueous slurry.

  17. High capacity immobilized amine sorbents

    DOEpatents

    Gray, McMahan L.; Champagne, Kenneth J.; Soong, Yee; Filburn, Thomas

    2007-10-30

    A method is provided for making low-cost CO.sub.2 sorbents that can be used in large-scale gas-solid processes. The improved method entails treating an amine to increase the number of secondary amine groups and impregnating the amine in a porous solid support. The method increases the CO.sub.2 capture capacity and decreases the cost of utilizing an amine-enriched solid sorbent in CO.sub.2 capture systems.

  18. Handling, transport and dispersion of sorbent powder for in-furnace injection. Third year final report

    SciTech Connect

    Fan, Liang-Shih; Bavarian, F.; Lee, R.J.; Hsia, Chung-wei; Abou-Zeida, E.; Jiang, Peijun; Dastidar, A.G.; Mahuli, S.

    1993-09-01

    The purpose of this study is to explain, using fundamental theories of interparticle forces, the difference in transport and dispersion between various sorbents. This project is closely tied with 1.1 through the focus of maximum utilization of sorbent materials used in the LIMB process. Interparticle forces lead to agglomeration or removal to transport tube walls of the sorbent fine particles, reducing sulfur removal capabilities. In the first and second years, the pneumatic transport of sorbent powders was investigated for four typical sorbent materials, calcium carbonate, dolomite, dolomitic hydrate and hydrated lime. Results indicate that hydrated lime has the best dispersion and flowability. Studies in the third year involved investigating improving the performance of hydrated lime with additives. The addition of calcium liposulfonate to the water of hydration appears to improve both the dispersibility and reactivity of the resulting product hydrate. Increased reactivity is closely tied to available surface area for reaction, as expected. However, in applications where powder flowability becomes important, such as in the use of hydrate in flue-gas desulfurization, a balance between the flowability and surface area must be considered. If the powder has poor flowability, the added surface area may not be utilized. Powder dispersion and the high-temperature are used to determine the dispersibility of the modified and unmodified sorbents at room temperature and at typical furnace temperatures. Results verify that an increase in dispersibility is realized with the liposulfonate-modified hydrate. Phase 1 results show this increased dispersibility to be due to electrostatic repulsion between liposulfonate molecules on the surface of the dry powder.

  19. The enhanced adsorption of sulfur compounds onto mesoporous Ni-AlKIT-6 sorbent, equilibrium and kinetic analysis.

    PubMed

    Subhan, Fazle; Yan, Zifeng; Peng, Peng; Ikram, Muhammad; Rehman, Sadia

    2014-04-15

    High performance nickel supported on mesoporous AlKIT-6 (Si/Al=15, 25, 50, 100) sorbents were prepared by incipient wetness impregnation (IWI) with ultrasonic aid for adsorptive desulfurization of commercial diesel and simulated fuels. The sorbents were characterized by N2 adsorption-desorption, XRD, NH3-TPD, Py-FT-IR, HRTEM, SEM and atomic absorption spectroscopy techniques. The analysis results confirmed that Aluminum atoms entered the framework and 20%Ni-AlKIT-6(15) can still retain three dimensional structure of AlKIT-6(15) and Ni is highly dispersed in the support. The kinetic pseudo second-order model and Langmuir isotherm are shown to exhibits the best fits of experimental data for the adsorption of thiophene (T), benzothiophene (BT) and dibenzothiophene (DBT) over AlKIT-6 and 5-30%Ni-AlKIT-6. Intraparticle diffusion and steric hindrance were the rate controlling step of the adsorption of T and DBT over AlKIT-6(15) and 20%Ni-AlKIT-6(15) as verified through the intraparticle diffusion model. The characterization of regenerated 20%Ni-AlKIT-6(15) revealed that three-dimensional cubic Ia3d symmetric structure was maintained in the sorbent after 6 successive desulfurization-regeneration cycles.

  20. The enhanced adsorption of sulfur compounds onto mesoporous Ni-AlKIT-6 sorbent, equilibrium and kinetic analysis.

    PubMed

    Subhan, Fazle; Yan, Zifeng; Peng, Peng; Ikram, Muhammad; Rehman, Sadia

    2014-04-15

    High performance nickel supported on mesoporous AlKIT-6 (Si/Al=15, 25, 50, 100) sorbents were prepared by incipient wetness impregnation (IWI) with ultrasonic aid for adsorptive desulfurization of commercial diesel and simulated fuels. The sorbents were characterized by N2 adsorption-desorption, XRD, NH3-TPD, Py-FT-IR, HRTEM, SEM and atomic absorption spectroscopy techniques. The analysis results confirmed that Aluminum atoms entered the framework and 20%Ni-AlKIT-6(15) can still retain three dimensional structure of AlKIT-6(15) and Ni is highly dispersed in the support. The kinetic pseudo second-order model and Langmuir isotherm are shown to exhibits the best fits of experimental data for the adsorption of thiophene (T), benzothiophene (BT) and dibenzothiophene (DBT) over AlKIT-6 and 5-30%Ni-AlKIT-6. Intraparticle diffusion and steric hindrance were the rate controlling step of the adsorption of T and DBT over AlKIT-6(15) and 20%Ni-AlKIT-6(15) as verified through the intraparticle diffusion model. The characterization of regenerated 20%Ni-AlKIT-6(15) revealed that three-dimensional cubic Ia3d symmetric structure was maintained in the sorbent after 6 successive desulfurization-regeneration cycles. PMID:24556462

  1. Novel sorbents for environmental remediation

    NASA Astrophysics Data System (ADS)

    Manariotis, Ioannis D.; Karapanagioti, Hrissi K.; Werner, David

    2014-05-01

    Nowadays, one of the major environmental problems is the pollution of aquatic systems and soil by persistent pollutants. Persistent pollutants have been found widespread in sediments, surface waters, and drinking water supplies. The removal of pollutants can be accomplished prior to their discharge to receiving bodies or by immobilizing them onto soil. Sorption is the most commonly applied process, and activated carbons have been widely used. Rapid progress in nanotechnology and a new focus on biomass-based instead of non-renewable starting materials have produced a wide range of novel engineered sorbents including biosorbents, biochars, carbon-based nanoparticles, bio-nano hybrid materials, and iron-impregnated activated carbons. Sorbent materials have been used in environmental remediation processes and especially in agricultural soil, sediments and contaminated soil, water treatment, and industrial wastewater treatment. Furthermore, sorbents may enhance the synergistic action of other processes, such as volatilization and biodegradation. Novel sorbents have been employed for the removal or immobilization of persistent pollutants such as and include heavy metals (As, Cr, Cu, Pb, Cd, and Hg), halogenated organic compounds, endocrine disrupting chemicals, metalloids and non-metallic elements, and other organic pollutants. The development and evaluation of novel sorbents requires a multidisciplinary approach encompassing environmental, nanotechnology, physical, analytical, and surface chemistry. The necessary evaluations encompass not only the efficiency of these materials to remove pollutants from surface waters and groundwater, industrial wastewater, polluted soils and sediments, etc., but also the potential side-effects of their environmental applications. The aim of this work is to present the results of the use of biochar and impregnated carbon sorbents for the removal of organic pollutants and metals. Furthermore, the new findings from the forthcoming session

  2. CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

    SciTech Connect

    David A. Green; Brian S. Turk; Raghubir P. Gupta; Alejandro Lopez-Ortiz; Douglas P. Harrison; Ya Liang

    2001-07-01

    Sodium based sorbents including sodium carbonate may be used to capture carbon dioxide from flue gas. A relatively concentrated carbon dioxide stream may be recoverable for sequestration when the sorbent is regenerated. Electrobalance tests indicated that sodium carbonate monohydrate was formed in a mixture of helium and water vapor at temperatures below 65 C. Additional compounds may also form, but this could not be confirmed. In the presence of carbon dioxide and water vapor, both the initial reaction rate of sodium carbonate with carbon dioxide and water and the sorbent capacity decreased with increasing temperature, consistent with the results from the previous quarter. Increasing the carbon dioxide concentration at constant temperature and water vapor concentration produced a measurable increase in rate, as did increasing the water vapor concentration at constant carbon dioxide concentration and temperature. Runs conducted with a flatter TGA pan resulted in a higher initial reaction rate, presumably due to improved gas-solid contact, but after a short time, there was no significant difference in the rates measured with the different pans. Analyses of kinetic data suggest that the surface of the sodium carbonate particles may be much hotter than the bulk gas due to the highly exothermic reaction with carbon dioxide and water, and that the rate of heat removal from the particle may control the reaction rate. A material and energy balance was developed for a cyclic carbonation/calcination process which captures about 26 percent of the carbon dioxide present in flue gas available at 250 C.

  3. Catalytic regeneration of mercury sorbents.

    PubMed

    Bentley, Mark; Fan, Maohong; Dutcher, Bryce; Tang, Mingchen; Argyle, Morris D; Russell, Armistead G; Zhang, Yulong; Sharma, M P; Swapp, Susan M

    2013-11-15

    Traditionally, mercury sorbents are disposed of in landfills, which may lead to contamination of soil and groundwater. In this work, the regeneration of activated carbon (AC) as a mercury sorbent was investigated. The decomposition of HgCl2 on the surface of pure AC was studied, as well as sorbent which has been treated with FeCl3 or NaCl. In all cases, the sorbent is found to be structurally stable through a single regeneration, which is verified through BET, XRD, and XPS analysis. The desorption of mercury from the sorbent is found to follow Henry's law. Additionally, a kinetic analysis suggests that although the presence of activated carbon lowers the energy requirement for the desorption of mercury, it significantly decreases the rate by decreasing the concentration of the HgCl2. FeCl3 and NaCl both promoted the decomposition of HgCl2, but FeCl3 did so more significantly, increasing the rate constants by a factor of 10 and decreasing the activation energy for the decomposition of HgCl2 by 14% to 40%.

  4. Stabilization and/or regeneration of spent sorbents from coal gasification

    SciTech Connect

    Abbasian, J.

    1991-01-01

    The objective of this investigation is to determine the effects of SO{sub 2} partial pressure and reaction temperature on the conversion of sulfide containing solid wastes from coal gasifiers to stable and environmentally acceptable calcium-sulfate, while preventing the release of sulfur dioxide through undesirable side reactions during the stabilization step. An additional objective of this program is to investigate the use of the Spent Sorbent Regeneration Process (SSRP) to regenerate spent limestone, from a fluidized-bed gasifier with in-bed sulfur capture, for recycling to the gasifier. To achieve these objectives, selected samples of partially sulfided sorbents will be reacted with oxygen at a variety of operating conditions under sufficient SO{sub 2} partial pressure to prevent release of sulfur from the solids during stabilization that reduces the overall sorbent utilization. Partially sulfided limestone will also be regenerated with water to produce calcium hydroxide and release sulfur as H{sub 2}S. The regenerated sorbent will be dewatered, dried and pelletized. The reactivity of the regenerated sorbent toward H{sub 2}S will also be determined. During this quarter sulfidation tests were conducted in a quartz fluidized-bed reactor in which the selected calcium-based sorbents were first calcined and then were reacted with hydrogen sulfide at ambient pressure and 1650{degree}F. These tests were conducted with each sorbent in two particle sizes. Chemical analyses of the partially sulfided sorbents indicate that the extent of sulfidation was in the range of 40--50%. The partially sulfided material will be reacted with oxygen to determine the effects of temperature and SO{sub 2} partial pressure on the stabilization of the calcium sulfide in solid waste materials. 23 refs., 1 fig., 2 tabs.

  5. Method for desulfurization of coal

    DOEpatents

    Kelland, David R.

    1987-01-01

    A process and apparatus for desulfurizing coal which removes sulfur in the inorganic and organic form by preferentially heating the inorganic iron sulfides in coal in a flowing gas to convert some of the inorganic iron sulfides from a pyrite form FeS.sub.2 to a troilite FeS form or a pyrrhotite form Fe.sub.1-x S and release some of the sulfur as a gaseous compound. The troilite and pyrrhotite forms are convenient catalyst for removing the organic sulfur in the next step, which is to react the coal with chemical agents such as alcohol, thus removing the organic sulfur as a liquid or a gas such as H.sub.2 S. The remaining inorganic sulfur is left in the predominantly higher magnetic form of pyrrhotite and is then removed by magnetic separation techniques. Optionally, an organic flocculant may be added after the organic sulfur has been removed and before magnetic separation. The flocculant attaches non-pyrite minerals with the pyrrhotite for removal by magnetic separation to reduce the ash-forming contents.

  6. Method for desulfurization of coal

    DOEpatents

    Kelland, D.R.

    1987-07-07

    A process and apparatus are disclosed for desulfurizing coal which removes sulfur in the inorganic and organic form by preferentially heating the inorganic iron sulfides in coal in a flowing gas to convert some of the inorganic iron sulfides from a pyrite form FeS[sub 2] to a troilite FeS form or a pyrrhotite form Fe[sub 1[minus]x]S and release some of the sulfur as a gaseous compound. The troilite and pyrrhotite forms are convenient catalyst for removing the organic sulfur in the next step, which is to react the coal with chemical agents such as alcohol, thus removing the organic sulfur as a liquid or a gas such as H[sub 2]S. The remaining inorganic sulfur is left in the predominantly higher magnetic form of pyrrhotite and is then removed by magnetic separation techniques. Optionally, an organic flocculant may be added after the organic sulfur has been removed and before magnetic separation. The flocculant attaches non-pyrite minerals with the pyrrhotite for removal by magnetic separation to reduce the ash-forming contents. 2 figs.

  7. Microbial desulfurization of different coals.

    PubMed

    Acharya, C; Kar, R N; Sukla, L B

    2004-01-01

    Coal is the most important nonrenewable energy source of fossil origin. It is also the most common fuel in thermal power plants. However, during coal incineration in power plants, high sulfur content of coal poses serious environmental problems owing to sulfur dioxide emission. We studied the application of microbial methods for removal of sulfur from three types of high sulfur coals-two samples collected from Assam and Rajasthan in India and one from Libiaz, Poland. These coal samples were desulfurized using indigenous Acidithiobacillus sp. After investigation of the effect of various parameters, the conditions optimized for the maximum removal of total sulfur (91.87% for lignite, 63.13% for Polish coal, and only 9.44% for Assam coal) were as follows: initial pH of 1.5 (2.5 in the case of Assam coal), particle size of 45 micro, pulp density of 2% (w/v), incubation period of 30 d at -35 degrees C in presence of 44.2 g/L of ferrous sulfate in the media with shaking at 140 rpm. Poor removal of sulfur in the case of Assam coal was owing to extensive precipitation of jarosites. In addition, the sulfur in Assam coal is mostly found in organic form, which is difficult to remove with Acidithiobacillus sp. The removal of sulfur from the three coal samples was demonstrated with photomicrographic studies. PMID:15304738

  8. Coal desulfurization by low-temperature chlorinolysis

    NASA Technical Reports Server (NTRS)

    Hsu, G. C.; Kalvinskas, J. J.; Ganguli, P. S.; Gavalas, G. R.

    1977-01-01

    Among the three principal methods for precombustion desulfurization of coal, which include physical depyriting, chemical desulfurization, and coal conversion to low-sulfur liquid and gaseous fuels, the potential of chemical methods looks promising in terms of both total sulfur removal and processing cost. The principal chemical methods for coal desulfurization involve treatment with either oxidizing agents or basic media at elevated temperature and pressure. A description is given of some recent experimental results which show the feasibility of removing sulfur, particularly organic sulfur, from high-sulfur coals by a simple method of low-temperature chlorinolysis followed by hydrolysis and dechlorination. The chemical feasibility of sulfur removal by chlorinolysis rather than the detailed engineering process is emphasized.

  9. Sol-gel derived sorbents

    DOEpatents

    Sigman, Michael E.; Dindal, Amy B.

    2003-11-11

    Described is a method for producing copolymerized sol-gel derived sorbent particles for the production of copolymerized sol-gel derived sorbent material. The method for producing copolymerized sol-gel derived sorbent particles comprises adding a basic solution to an aqueous metal alkoxide mixture for a pH.ltoreq.8 to hydrolyze the metal alkoxides. Then, allowing the mixture to react at room temperature for a precalculated period of time for the mixture to undergo an increased in viscosity to obtain a desired pore size and surface area. The copolymerized mixture is then added to an immiscible, nonpolar solvent that has been heated to a sufficient temperature wherein the copolymerized mixture forms a solid upon the addition. The solid is recovered from the mixture, and is ready for use in an active sampling trap or activated for use in a passive sampling trap.

  10. VALUE-ADDED SORBENT DEVELOPMENT

    SciTech Connect

    Grant E. Dunham; Edwin S. Olson; Stanley J. Miller

    2000-07-01

    On a worldwide basis, the projected increase in coal usage over the next two decades in China, India, and Indonesia will dwarf the current U.S. coal consumption of 1 billion tons/year. Therefore, in the United States, coal will be the dominant source of mercury emissions, and worldwide, coal may be the cause of significantly increased mercury emissions unless an effective control strategy is implemented. However, there is much uncertainty over the most technically sound and cost-effective approach for reducing mercury emissions from coal-fired boilers. Several approaches are suggested for mercury control from coal-fired boilers, including enhancing the ability of wet scrubbers to retain mercury. However, many coal-fired boilers are not equipped with wet scrubbers. On the other hand, since almost all coal-fired boilers are equipped with either an electrostatic precipitator (ESP) or a baghouse, sorbent injection upstream of either an ESP or baghouse appears attractive, because it has the potential to control both Hg{sup 0} and Hg{sup 2+}, would appear to be easy to retrofit, and would be applicable to both industrial and utility boilers. Since mercury in the gas stream from coal combustion is present in only trace quantities, only very small amounts of sorbent may be necessary. If we assume a mercury concentration of 10 {micro}g/m{sup 3} and a sorbent-to-mercury mass ratio of 1000:1, the required sorbent loading is 10 mg/m{sup 3}, which is only 0.1% to 0.2% of a typical dust loading of 5-10 g/m{sup 3} (2.2-4.4 grains/scf). This amount of additional sorbent material in the ash would appear to be negligible and would not be expected to have an impact on control device performance or ash utilization. Accomplishing effective mercury control with sorbent injection upstream of a particulate control device requires several critical steps: (1) Dispersion of the small sorbent particles and mixing with the flue gas must be adequate to ensure that all of the gas is effectively

  11. Sorbent characterization for FBC application

    SciTech Connect

    Pisupati, S.V.; Scaroni, A.W.

    1994-12-31

    Fluidized-bed boilers operating at both atmospheric and elevated pressures have received considerable attention from utilities and independent power producers because of their ability to remove SO{sub 2} from the flue gas during combustion and to minimize NO{sub x} production. The technology has advanced rapidly in the 1980s because of its adaptability to a range of fuel types, boiler capacities, and operating conditions without seriously compromising efficiency or performance. A sorbent, typically limestone or dolostone, is used in the fluidized-bed boiler to capture the combustion-generated SO{sub 2}. Many CFBC boiler operators are now realizing that optimizing sorbent usage is important for economical and environmentally acceptable operation of their plants. It is reported (mostly based on studies using a few sorbents) that particle size, porosity and pore size distribution, extent of sulfation, combustor temperature, pressure and CaCO{sub 3} content affect extent of sulfation.

  12. Testing and technology transfer for zinc titanate sorbent in a titania matrix. Technical report, September 1, 1995--November 30, 1995

    SciTech Connect

    Swisher, J.H.; Gupta, R.P.

    1995-12-31

    For new coal gasification systems, zinc-based sorbents are being developed to remove sulfur from the hot product gas prior to its use in combined-cycle gas turbines and high- temperature fuel cells. In general, the properties of these sorbents are considered to be very attractive, but there are still concerns about degradation of mechanical properties and sulfur capacity over many sulfidation- regeneration cycles. It is believed that containing zinc titanate in a matrix of excess titania could solve both problems, which is the objective of this project. During this quarter, plans were made for United Catalysts, Inc. to produce two batches of the sorbent using a commercial extrusion process. A subcontract was just issued to the Research Triangle Institute for sorbent characterization and for a 50- cycle performance test designed to simulate the General Electric Company`s moving-bed reactor conditions. In a parallel effort, numerous contacts were made on the technology transfer task.

  13. Carbon sorbent based on flax boon

    SciTech Connect

    Abramov, M.V.; Tyulina, R.M.; Yaroslavtsev, V.T.

    1994-11-10

    Flax-fiber production wastes such as boon can be used effectively as the starting material for producing carbon sorbents. Activated carbons are among the most widely used sorbents in industrial wastewater and waste gas treatment. A single-stage process has been developed for producing an efficient, cheap carbon sorbent based on flax boon.

  14. High Temperature Sorbents for Oxygen

    NASA Technical Reports Server (NTRS)

    Sharma, Pramod K. (Inventor)

    1996-01-01

    A sorbent capable of removing trace amounts of oxygen (ppt) from a gas stream at a high temperature above 200 C is introduced. The sorbent comprises a porous alumina silicate support such as zeolite containing from 1 to 10 percent by weight of ion exchanged transition metal such as copper or cobalt ions and 0.05 to 1.0 percent by weight of an activator selected from a platinum group metal such as platinum. The activation temperature, oxygen sorption and reducibility are all improved by the presence of the platinum activator.

  15. CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

    SciTech Connect

    David A. Green; Brian S. Turk; Raghubir P. Gupta; William J. McMichael; Douglas P. Harrison; Ya Liang

    2002-04-01

    The objective of this project is to develop a simple, inexpensive process to separate CO{sub 2} as an essentially pure stream from a fossil fuel combustion system using a regenerable, sodium-based sorbent. The sorbents being investigated in this project are primarily alkali carbonates, and particularly sodium carbonate and potassium carbonate, which are converted to bicarbonates, through reaction with carbon dioxide and water vapor. Bicarbonates are regenerated to carbonates when heated, producing a nearly pure CO{sub 2} stream after condensation of water vapor. This quarter, electrobalance tests conducted at LSU indicated that exposure of sorbent to water vapor prior to contact with carbonation gas does not significantly increase the reaction rate. Calcined fine mesh trona has a greater initial carbonation rate than calcined sodium bicarbonate, but appears to be more susceptible to loss of reactivity under severe calcination conditions. The Davison attrition indices for Grade 5 sodium bicarbonate, commercial grade sodium carbonate and extra fine granular potassium carbonate were, as tested, outside of the range suitable for entrained bed reactor testing. Fluidized bed testing at RTI indicated that in the initial stages of reaction potassium carbonate removed 35% of the carbon dioxide in simulated flue gas, and is reactive at higher temperatures than sodium carbonate. Removals declined to 6% when 54% of the capacity of the sorbent was exhausted. Carbonation data from electrobalance testing was correlated using a shrinking core reaction model. The activation energy of the reaction of sodium carbonate with carbon dioxide and water vapor was determined from nonisothermal thermogravimetry.

  16. Design of a sorbent to enhance reactive adsorption of hydrogen sulfide.

    PubMed

    Wang, Long-Jiang; Fan, Hui-Ling; Shangguan, Ju; Croiset, Eric; Chen, Zhongwei; Wang, Hui; Mi, Jie

    2014-12-10

    A series of novel zinc oxide-silica composites with three-dimensionally ordered macropores (3DOM) structure were synthesized via colloidal crystal template method and used as sorbents for hydrogen sulfide (H2S) removal at room temperature for the first time. The performances of the prepared sorbents were evaluated by dynamic breakthrough testing. The materials were characterized before and after adsorption using scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS). It was found that the composite with 3DOM structure exhibited remarkable desulfurization performance at room temperature and the enhancement of reactive adsorption of hydrogen sulfide was attributed to the unique structure features of 3DOM composites; high surface areas, nanocrystalline ZnO and the well-ordered interconnected macroporous with abundant mesopores. The introduction of silica could be conducive to support the 3DOM structure and the high dispersion of zinc oxide. Moisture in the H2S stream plays a crucial role in the removal process. The effects of Zn/Si ratio and the calcination temperature of 3DOM composites on H2S removal were studied. It demonstrated that the highest content of ZnO could reach up to 73 wt % and the optimum calcination temperature was 500 °C. The multiple adsorption/regeneration cycles showed that the 3DOM ZnO-SiO2 sorbent is stable and the sulfur capacity can still reach 67.4% of that of the fresh sorbent at the fifth cycle. These results indicate that 3DOM ZnO-SiO2 composites will be a promising sorbent for H2S removal at room temperature.

  17. Pilot-plant technical assessment of wet flue gas desulfurization using limestone

    SciTech Connect

    Ortiz, F.J.G.; Vidal, F.; Ollero, P.; Salvador, L.; Cortes, V.; Gimenez, A.

    2006-02-15

    An experimental study was performed on a countercurrent pilot-scale packed scrubber for wet flue gas desulfurization (FGD). The flow rate of the treated flue gas was around 300 Nm{sup 3}/h, so the pilot-plant capacity is one of the largest with respect to other published studies on a pilot-plant wet FGD. The tests were carried out at an SO{sub 2} inlet concentration of 2000 ppm by changing the recycle slurry pH to around 4.8 and the L/G ratio to between 7.5 and 15. Three types of limestone were tested, obtaining desulfurization efficiencies from 59 to 99%. We show the importance of choosing an appropriate limestone in order to get a better performance from the FGD plant. Thus, it is important to know the reactivity (on a laboratory scale) and the sorbent utilization (on a pilot-plant scale) in order to identify if a limestone is reactive enough and to compare it with another type. In addition, by using the transfer-unit concept, a function has been obtained for the desulfurization efficiency, using the L/G ratio and the recycle slurry pH as independent variables. The Ca/S molar ratio is related to these and to the SO{sub 2} removal efficiency. This function, together with a simplified function of the operation variable cost, allows us to determine the pair (L/G ratio and pH) to achieve the desired SO{sub 2} removal with the minimum operation cost. Finally, the variable operation costs between packed towers and spray scrubbers have been compared, using as a basis the pilot packed tower and the industrial spray column at the Compostilla Power Station's FGD plant (in Leon, Spain).

  18. Land application uses for dry flue gas desulfurization by-products: Phase 3

    SciTech Connect

    Dick, W.; Bigham, J.; Forster, R.; Hitzhusen, F.; Lal, R.; Stehouwer, R.; Traina, S.; Wolfe, W.; Haefner, R.; Rowe, G.

    1999-01-31

    New flue gas desulfurization (FGD) scrubbing technologies create a dry, solid by-product material consisting of excess sorbent, reaction product that contains sulfate and sulfite, and coal fly ash. Generally, dry FGD by-products are treated as solid wastes and disposed in landfills. However, landfill sites are becoming scarce and tipping fees are constantly increasing. Provided the environmental impacts are socially and scientifically acceptable, beneficial uses via recycling can provide economic benefits to both the producer and the end user of the FGD. A study titled ''Land Application Uses for Dry Flue Gas Desulfurization By-Products'' was initiated in December, 1990 to develop and demonstrate large volume, beneficial uses of FGD by-products. Phase 1 and Phase 2 reports have been published by the Electric Power Research Institute (EPRI), Palo Alto, CA. Phase 3 objectives were to demonstrate, using field studies, the beneficial uses of FGD by-products (1) as an amendment material on agricultural lands and on abandoned surface coal mine land, (2) as an engineering material for soil stabilization and raid repair, and (3) to assess the environmental and economic impacts of such beneficial uses. Application of dry FGD by-product to three soils in place of agricultural limestone increased alfalfa (Medicago sativa L.) and corn (Zea may L.) yields. No detrimental effects on soil and plant quality were observed.

  19. Macroscopic to microscopic studies of flue gas desulfurization byproducts for acid mine drainage mitigation

    SciTech Connect

    Robbins, E.I.; Kalyoncu, R.S.; Finkelman, R.B.; Matos, G.R.; Barsotti, A.F.; Haefner, R.J.; Rowe, G.L. Jr.; Savela, C.E.; Eddy, J.I.

    1996-12-31

    The use of flue gas desulfurization (FGD) systems to reduce SO{sub 2} emissions has resulted in the generation of large quantities of byproducts. These and other byproducts are being stockpiled at the very time that alkaline materials having high neutralization potential are needed to mitigate acid mine drainage (AMD). FGD byproducts are highly alkaline materials composed primarily of unreacted sorbents (lime or limestone and sulfates and sulfites of Ca). The American Coal Ash Association estimated that approximately 20 million tons of FGD material were generated by electric power utilities equipped with wet lime-limestone PGD systems in 1993. Less than 5% of this material has been put to beneficial use for agricultural soil amendments and for the production of wallboard and cement. Four USGS projects are examining FGD byproduct use to address these concerns. These projects involve (1) calculating the volume of flue gas desulfurization (FGD) byproduct generation and their geographic locations in relation to AMD, (2) determining byproduct chemistry and mineralogy, (3) evaluating hydrology and geochemistry of atmospheric fluidized bed combustion byproduct as soil amendment in Ohio, and (4) analyzing microbial degradation of gypsum in anoxic limestone drains in West Virginia.

  20. Development of novel copper-based sorbents for hot-gas cleanup. Technical report, March 1, 1992--May 31, 1992

    SciTech Connect

    Abbasian, J.; Hill, A.H.; Wangerow, J.R.; Flytzani-Stephanopoulos, M.; Bo, L.; Patel, C.

    1992-10-01

    The objective of this investigation is to evaluate several novel copper-based binary oxides for their suitability as regenerable sorbents for hot gas cleanup application in the temperature range of 650{degrees} to 850{degrees}C. During this quarter cyclic sulfidation/regeneration tests of the sorbents Cu{sub 2}Cr-O and Cu-Ce-0 were conducted using different compositions of the feed gases to investigate the effects of H{sub 2}0, H{sub 2} and CO. These tests were conducted in a packed-bed microreactor at 850{degrees}C. The results of these tests showed that H{sub 2} and CO (along with C02) had a significant effect on the H{sub 2}S pre-breakthrough levels, whereas H{sub 2}0 did not have an effect. The physical properties of the fresh and reacted samples of the Cu-2Cr-O and Cu-Ce-0 sorbents prepared in this program and used in the cyclic sulfidation/regeneration tests were also measured. In addition, sulfidation/regeneration tests were conducted using two commercial copper chromite sorbents (G-13 and G-89, United Catalyst, Inc.) and a zinc titanate sorbent (L-3014) in a one-inch fluidized-bed reactor at 650{degrees}C. The G-13 sorbent appears to have a much higher sulfur capacity than the G-89 sorbent.

  1. Regenerable Fe-Mn-ZnO/SiO2 sorbents for room temperature removal of H2S from fuel reformates: performance, active sites, Operando studies.

    PubMed

    Dhage, Priyanka; Samokhvalov, Alexander; Repala, Divya; Duin, Evert C; Tatarchuk, Bruce J

    2011-02-14

    Fe- and Mn-promoted H(2)S sorbents Fe(x)-Mn(y)-Zn(1-x-y)O/SiO(2) (x, y = 0, 0.025) for desulfurization of model fuel reformates at room temperature were prepared, tested and characterized. Sulfur uptake capacity at 25 °C significantly exceeds that of both commercial unsupported ZnO sorbents and un-promoted supported ZnO/SiO(2) sorbents. Sulfur capacity and breakthrough characteristics remain satisfactory after multiple (∼10) cycles of adsorption/regeneration, with regeneration performed by a simple and robust heating in air. XRD shows that both "calcined" and "spent" sorbents contain nano-dispersed ZnO, and XPS confirms conversion of ZnO to ZnS. "Calcined" sorbent contains Fe(3+) and Mn(3+) that are reduced to Mn(2+) upon reaction with H(2)S, but not with H(2). Operando ESR is used for the first time to study dynamics of reduction of Mn(3+) promoter sites simultaneously with measuring sulfidation dynamics of the Fe(x)-Mn(y)-Zn(1-x-y)O/SiO(2) sorbent. Fe cations are believed to occupy the surface of supported ZnO nanocrystallites, while Mn cations are distributed within ZnO.

  2. PROCEEDINGS: MULTIPOLLUTANT SORBENT REACTIVITY WORKSHOP

    EPA Science Inventory

    The report is a compilation of technical papers and visual aids presented by representatives of industry, academia, and government agencies at a workshop on multipollutant sorbent reactivity that was held at EPA's Environmental Research Center in Research Triangle Park, NC, on Ju...

  3. Catalytic desulfurization of industrial waste gases

    SciTech Connect

    Dupin, Th.

    1985-07-30

    Industrial waste gases containing objectionable/polluting compounds of sulfur, e.g., H/sub 2/S, SO/sub 2/ and such organosulfur derivatives as COS, CS/sub 2/ and mercaptans, are catalytically desulfurized, e.g., by Claus process, employing an improved catalyst comprising titanium dioxide and calcium, barium, strontium or magnesium sulfate.

  4. Low-Cost Aqueous Coal Desulfurization

    NASA Technical Reports Server (NTRS)

    Kalvinskas, J. J.; Vasilakos, N.; Corcoran, W. H.; Grohmann, K.; Rohatgi, N. K.

    1982-01-01

    Water-based process for desulfurizing coal not only eliminates need for costly organic solvent but removes sulfur more effectively than an earlier solvent-based process. New process could provide low-cost commercial method for converting high-sulfur coal into environmentally acceptable fuel.

  5. Recombinant DNA encoding a desulfurization biocatalyst

    DOEpatents

    Rambosek, John; Piddington, Chris S.; Kovacevich, Brian R.; Young, Kevin D.; Denome, Sylvia A.

    1994-01-01

    This invention relates to a recombinant DNA molecule containing a gene or genes which encode a biocatalyst capable of desulfurizing a fossil fuel which contains organic sulfur molecules. For example, the present invention encompasses a recombinant DNA molecule containing a gene or genes of a strain of Rhodococcus rhodochrous.

  6. Recombinant DNA encoding a desulfurization biocatalyst

    DOEpatents

    Rambosek, J.; Piddington, C.S.; Kovacevich, B.R.; Young, K.D.; Denome, S.A.

    1994-10-18

    This invention relates to a recombinant DNA molecule containing a gene or genes which encode a biocatalyst capable of desulfurizing a fossil fuel which contains organic sulfur molecules. For example, the present invention encompasses a recombinant DNA molecule containing a gene or genes of a strain of Rhodococcus rhodochrous. 13 figs.

  7. Microbial desulfurization of organic sulfur compounds in petroleum.

    PubMed

    Ohshiro, T; Izumi, Y

    1999-01-01

    Sulfur removal from petroleum is important from the standpoint of the global environment because the combustion of sulfur compounds leads to the production of sulfur oxides, which are the source of acid rain. As the regulations for sulfur in fuels become more stringent, the existing chemical desulfurizations are coming inadequate for the "deeper desulfurization" to produce lower-sulfur fuels without new and innovative processes. Biodesulfurization is rising as one of the candidates. Several microorganisms were found to desulfurize dibenzothiophene (DBT), a representative of the organic sulfur compounds in petroleum, forming a sulfur-free compound, 2-hydroxybiphenyl. They are promising as biocatalysts in the microbial desulfurization of petroleum because without assimilation of the carbon content, they remove only sulfur from the heterocyclic compounds which is refractory to conventional chemical desulfurization. Both enzymological and molecular genetic studies are now in progress for the purpose of obtaining improved desulfurization activity of organisms. The genes involved in the sulfur-specific DBT desulfurization were identified and the corresponding enzymes have been investigated. From the practical point of view, it has been proved that the microbial desulfurization proceeds in the presence of high concentrations of hydrocarbons, and more complicated DBT analogs are also desulfurized by the microorganisms. This review outlines the progress in the studies of the microbial desulfurization from the basic and practical point of view.

  8. Chemical and physical properties of dry flue gas desulfurization products.

    PubMed

    Kost, David A; Bigham, Jerry M; Stehouwer, Richard C; Beeghly, Joel H; Fowler, Randy; Traina, Samuel J; Wolfe, William E; Dick, Warren A

    2005-01-01

    Beneficial and environmentally safe recycling of flue gas desulfurization (FGD) products requires detailed knowledge of their chemical and physical properties. We analyzed 59 dry FGD samples collected from 13 locations representing four major FGD scrubbing technologies. The chemistry of all samples was dominated by Ca, S, Al, Fe, and Si and strong preferential partitioning into the acid insoluble residue (i.e., coal ash residue) was observed for Al, Ba, Be, Cr, Fe, Li, K, Pb, Si, and V. Sulfur, Ca, and Mg occurred primarily in water- or acid-soluble forms associated with the sorbents or scrubber reaction products. Deionized water leachates (American Society for Testing and Materials [ASTM] method) and dilute acetic acid leachates (toxicity characteristic leaching procedure [TCLP] method) had mean pH values of >11.2 and high mean concentrations of S primarily as SO(2-)4 and Ca. Concentrations of Ag, As, Ba, Cd, Cr, Hg, Pb, and Se (except for ASTM Se in two samples) were below drinking water standards in both ASTM and TCLP leachates. Total toxicity equivalents (TEQ) of dioxins, for two FGD products used for mine reclamation, were 0.48 and 0.53 ng kg(-1). This was similar to the background level of the mine spoil (0.57 ng kg(-1)). The FGD materials were mostly uniform in particle size. Specific surface area (m2 g(-1)) was related to particle size and varied from 1.3 for bed ash to 9.5 for spray dryer material. Many of the chemical and physical properties of these FGD samples were associated with the quality of the coal rather than the combustion and SO2 scrubbing processes used.

  9. FURNACE INJECTION OF ALKALINE SORBENTS FOR SULFURIC ACID REMOVAL

    SciTech Connect

    Gary M. Blythe

    2004-01-01

    The objective of this project has been to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. The project was co-funded by the U.S. DOE National Energy Technology Laboratory under Cooperative Agreement DE-FC26-99FT40718, along with EPRI, the American Electric Power Company (AEP), FirstEnergy Corporation, the Tennessee Valley Authority, and Carmeuse North America. Sulfuric acid controls are becoming of increased interest for coal-fired power generating units for a number of reasons. In particular, sulfuric acid can cause plant operation problems such as air heater plugging and fouling, back-end corrosion, and plume opacity. These issues will likely be exacerbated with the retrofit of selective catalytic reduction (SCR) for NOX control, as SCR catalysts are known to further oxidize a portion of the flue gas SO{sub 2} to SO{sub 3}. The project tested the effectiveness of furnace injection of four different magnesium-based or dolomitic alkaline sorbents on full-scale utility boilers. These reagents were tested during one- to two-week tests conducted on two FirstEnergy Bruce Mansfield Plant (BMP) units. One of the sorbents tested was a magnesium hydroxide slurry byproduct from a modified Thiosorbic{reg_sign} Lime wet flue gas desulfurization process. The other three sorbents are available commercially and include dolomite, pressure-hydrated dolomitic lime, and commercially available magnesium hydroxide. The dolomite reagent was injected as a dry powder through out-of-service burners. The other three reagents were injected as slurries through air-atomizing nozzles inserted through the front wall of the upper furnace. After completing the four one- to two-week tests, the most promising sorbents were selected for longer-term (approximately 25-day) full-scale tests on two different units. The longer-term tests were conducted to confirm sorbent effectiveness over extended operation on two

  10. Characterization of active sites, determination of mechanisms of H(2)S, COS and CS(2) sorption and regeneration of ZnO low-temperature sorbents: past, current and perspectives.

    PubMed

    Samokhvalov, Alexander; Tatarchuk, Bruce J

    2011-02-28

    The intellectually and technically challenging pursuit of the emerging global environmentally "green" and energy-efficient infrastructure of the 21st century requires the development of a worldwide network of low- to medium-power fuel cell (FC) based portable electric power-generating devices and high-power biomass/clean coal "electric+chemical plants" with zero carbon footprint utilizing integrated coal gasification combined cycle with geologic carbon sequestration (IGCC-GCS) under energy-efficient low-temperature conditions. These emerging technologies require the deep and ultradeep desulfurization of gaseous feeds, since sulfur compounds, especially hydrogen sulfide H(2)S are highly corrosive and poisonous to both technological processes and the environment. Therefore, it is of crucial importance for both academic and industrial research communities to have a solid understanding of the atomic-level structures of active sites and molecular-level mechanisms of surface chemical reactions of the novel deep and ultradeep desulfurization materials, especially desulfurization sorbents. This review critically analyzes the recent literature (last ∼20 years) on the experimental determination of molecular and atomic-level nature of adsorption sites, effects of desulfurization promoters, mechanisms of chemical reactions of H(2)S, COS and CS(2) and physical processes during and upon regeneration of "spent" low-temperature H(2)S sorbents based on ZnO that were developed for desulfurization of fuel reformates, syngas and similar streams. Recent trends in research on the ultradeep H(2)S sorbents are discussed with an impetus on real-time in situ and Operando techniques of instrumental chemical analysis, and the challenges of direct determination of the structure of active sites and of the experimental mechanistic studies in general are described.

  11. DEVELOPMENT OF DISPOSABLE SORBENTS FOR CHLORIDE REMOVAL FROM HIGH TEMPERATURE COAL-DERIVED GASES

    SciTech Connect

    Gopala Krishnan; Raghubir Gupta

    1999-09-01

    Advanced integrated-gasification combined-cycle (IGCC) and integrated-gasification fuel cell (IGFC) systems require the development of high temperature sorbents for the removal of hydrogen chloride (HCl) vapor to less than 1 parts-per-million (ppm) levels. HCl is a highly reactive, corrosive, and toxic gas which must be removed to meet environmental regulations, to protect power generation equipment, and to minimize deterioration of hot gas desulfurization sorbents. The objective of this program was to develop disposable, alkali-based sorbents capable of reducing HCl vapor levels to less than 1 ppm in the temperature range from 400 to 750 C and pressures in the range from 1 to 20 atm. The primary areas of focus of this program were to investigate different methods of sorbent fabrication, testing their suitability for different reactor configurations, obtaining reaction kinetics data, and conducting a preliminary economic feasibility assessment. This program was a joint effort between SRI International (SRI), Research Triangle Institute (RTI), and General Electric Corporate Research and Development (GE-CRD). SRI, the prime contractor and RTI, a major subcontractor, performed most of the work in this program. Thermochemical calculations indicated that sodium-based sorbents were capable of reducing HCl vapor levels to less than 1 ppm at temperatures up to 650 C, but the regeneration of spent sorbents would require complex process steps. Nahcolite (NaHCO{sub 3}), a naturally-occurring mineral, could be used as an inexpensive sorbent to remove HCl vapor in hot coal gas streams. In the current program, nahcolite powder was used to fabricate pellets suitable for fixed-bed reactors and granules suitable for fluidized-bed reactors. Pilot-scale equipment were used to prepare sorbents in large batches: pellets by disk pelletization and extrusion techniques, and granules by granulation and spray-drying techniques. Bench-scale fixed- and fluidized-bed reactors were assembled at

  12. Effects of salts on preparation and use of calcium silicates for flue gas desulfurization

    SciTech Connect

    Kind, K.K.; Wassermann, P.D.; Rochelle, G.T. )

    1994-02-01

    High surface area calcium silicate hydrates that are highly reactive with SO[sub 2] can be made by slurrying fly ash and lime in water at elevated temperatures for several hours. This concept is the basis for the ADVACATE (ADVAnced siliCATE) process for flue gas desulfurization. This paper examines the impact of salts on such a system. Two low calcium fly ashes, from the Shawnee and Clinch River power plants, were examined. The addition of gypsum (CaSO[sub 4][center dot]2H[sub 2]O) or calcium chloride to the slurry system increased the dissolved calcium concentration, allowing the reaction rate to increase and the maximum surface area to more than double in some cases. This increase came despite a lower solution hydroxide level. The salts also enhanced the reaction of the sorbent with sulfur dioxide. This resulted from the higher equilibrium moisture on the sorbent at any humidity due to the deliquescent properties of some of the salts used (calcium chloride and calcium nitrate). Solids made without the deliquescent salts exhibited equilibrium moisture adsorption consistent with a type-II BET isotherm while the deliquescent salts caused hysteresis in the adsorption/desorption isotherm. 22 refs., 10 figs., 2 tabs.

  13. Development of novel copper-based sorbents for hot-gas cleanup. Technical report, 1 March--31 May 1994

    SciTech Connect

    Abbasian, J.; Hill, A.H.; Flytzani-Stephanopoulos, M.; Li, Z.

    1994-09-01

    The objective of this investigation is to evaluate two novel copper-based sorbents, namely copper-chromium and copper-cerium, for their effectiveness in removing hydrogen sulfide from fuel gas in the temperature range of 650 to 850 C. Such high temperatures will be required for the new generation of gas turbines (inlet > 750 C) in Integrated Gasification Combined Cycle (IGCC) systems. Results of fixed-bed reactor tests conducted in this quarter, indicate that, at 750 C, pre-reduction with H{sub 2} in the presence of H{sub 2}O does not effect the performance of either sorbent for H{sub 2}S removal. For the pre-reduced CuCr{sub 2}O{sub 4} sorbent, copper utilization before the first H{sub 2}S breakthrough is substantially higher in synthesis feed gas mixture than in feed gas containing 30 Vol% H{sub 2}, and slightly lower than in 10 vol% H{sub 2}. In sulfidation-regeneration testing of copper- and additive-rich sorbents, chromium-rich CuO-3Cr{sub 2}O{sub 4} sorbent demonstrated very high H{sub 2}S removal efficiency and high copper conversion levels (comparable to that of the 1:1 molar composition sorbent). Similar results were obtained with the cerium-rich CuO-3CeO{sub 2} sorbent, but only for the first cycle. The H{sub 2}S removal performance of both copper-rich sorbents was inferior to that of the respective 1:1 molar compositions. CuO-CeO{sub 2} sorbent testing in a TGA indicates no appreciable decrease in the sulfidation rate over 5 1/2 cycles. However, weight changes during regeneration of the CuO-CeO{sub 2} suggest that some copper or cerium sulfates formed.

  14. High capacity carbon dioxide sorbent

    DOEpatents

    Dietz, Steven Dean; Alptekin, Gokhan; Jayaraman, Ambalavanan

    2015-09-01

    The present invention provides a sorbent for the removal of carbon dioxide from gas streams, comprising: a CO.sub.2 capacity of at least 9 weight percent when measured at 22.degree. C. and 1 atmosphere; an H.sub.2O capacity of at most 15 weight percent when measured at 25.degree. C. and 1 atmosphere; and an isosteric heat of adsorption of from 5 to 8.5 kilocalories per mole of CO.sub.2. The invention also provides a carbon sorbent in a powder, a granular or a pellet form for the removal of carbon dioxide from gas streams, comprising: a carbon content of at least 90 weight percent; a nitrogen content of at least 1 weight percent; an oxygen content of at most 3 weight percent; a BET surface area from 50 to 2600 m.sup.2/g; and a DFT micropore volume from 0.04 to 0.8 cc/g.

  15. Decontamination formulation with sorbent additive

    DOEpatents

    Tucker; Mark D. , Comstock; Robert H.

    2007-10-16

    A decontamination formulation and method of making that neutralizes the adverse health effects of both chemical and biological compounds, especially chemical warfare (CW) and biological warfare (BW) agents, and toxic industrial chemicals. The formulation provides solubilizing compounds that serve to effectively render the chemical and biological compounds, particularly CW and BW compounds, susceptible to attack, and at least one reactive compound that serves to attack (and detoxify or kill) the compound. The formulation includes at least one solubilizing agent, a reactive compound, a bleaching activator, a sorbent additive, and water. The highly adsorbent, water-soluble sorbent additive (e.g., sorbitol or mannitol) is used to "dry out" one or more liquid ingredients, such as the liquid bleaching activator (e.g., propylene glycol diacetate or glycerol diacetate) and convert the activator into a dry, free-flowing powder that has an extended shelf life, and is more convenient to handle and mix in the field.

  16. Photopatternable sorbent and functionalized films

    DOEpatents

    Grate, Jay W.; Nelson, David A.

    2006-01-31

    A composition containing a polymer, a crosslinker and a photo-activatable catalyst is placed on a substrate. The composition is exposed to a predetermined pattern of light, leaving an unexposed region. The light causes the polymer to become crosslinked by hydrosilylation. A solvent is used to remove the unexposed composition from the substrate, leaving the exposed pattern to become a sorbent polymer film that will absorb a predetermined chemical species when exposed to such chemical species.

  17. Crystalline marble beats limestone for fluegas desulfurization

    SciTech Connect

    1996-05-01

    NovaCon Energy Systems, Inc. (Bedford, NY) has developed an alternative to conventional limestone sorbents. The new process uses a class of marble, selected with a proprietary model. Recent pilot- and full-scale demonstrations in pulverized-coal (PC) and circulating fluidized bed (CFB) boilers suggest that these patented sorbents outperform conventional limestone for the simultaneous control of SOx, NOx, and particulates during the combustion of coal and sulfur-rich fuels, such as oil, mixed municipal waste and used tires. Dubbed thermally active marbles (TAMs), these sorbents are chemically identical to grainy limestone (whose main constituent is calcium carbonate or calcite). However, thanks to the increased pressures and temperatures experienced during their geologic history, these metamorphic minerals have a regular crystalline structure that offers some advantages in the combustion zone. TAMs, on the other hand, enjoy better calcium-utilization rates because upon heating, they cleave along inter- and intra-crystalline faces, continuously exposing fresh surfaces. By minimizing the self-extinguishment suffered by limestone sorbents, TAMs are effective over operating temperatures from 1,200 F to 2,800 F, which is 400 F higher than other calcium-based sorbents. This allows them to be injected closer to the burner or combustion grate to maximize residence time in the unit.

  18. Desulfurizing Coal With an Alkali Treatment

    NASA Technical Reports Server (NTRS)

    Ravindram, M.; Kalvinskas, J. J.

    1987-01-01

    Experimental coal-desulfurization process uses alkalies and steam in fluidized-bed reactor. With highly volatile, high-sulfur bituminous coal, process removed 98 percent of pyritic sulfur and 47 percent of organic sulfur. Used in coal liquefaction and in production of clean solid fuels and synthetic liquid fuels. Nitrogen or steam flows through bed of coal in reactor. Alkalies react with sulfur, removing it from coal. Nitrogen flow fluidizes bed while heating or cooling; steam is fluidizing medium during reaction.

  19. Philippine refiner completes diesel desulfurization project

    SciTech Connect

    Candido, S.S.; Crisostomo, E.V.

    1997-01-27

    In anticipation of tightening sulfur specifications on diesel fuel, Petron Corp. built a new 18,000 b/sd gas oil desulfurization unit (GODU) at its refinery in Bataan, Philippines. The GODU gives Petron sufficient diesel oil desulfurization capacity to meet demand for lower-sulfur diesel in the country. The project places the refinery in a pacesetter position to comply with the Philippine government`s moves to reduce air pollution, especially in urban centers, by reducing the sulfur specification for diesel to 0.5 wt% in 1996 from 0.7 wt% at the start of the project. Performance tests and initial operations of the unit have revealed a desulfurization efficiency of 91% vs. a guaranteed efficiency of 90%. A feed sulfur content of 1.33 wt% is reduced to 0.12 wt% at normal operating conditions. Operating difficulties during start-up were minimized through use of a detailed prestartup check conducted during the early stages of construction work.

  20. Biological desulfurization (BDS) of middle distillates

    SciTech Connect

    Monticello, D.J. )

    1993-01-01

    As implementation of the Clean Air Act Amendment draws near, sulfur management will play a key role for the refining industry. Industry experts have estimated that the petroleum industry will spend billions of dollars to conform to the Clean Air Act and desulfurization capacity will account for a significant portion of those expenditures. The need to limit the sulfur content of finished products is not new, but this dramatic increase in expenditures is the result of the increasingly stringent environmental regulations in the US, Europe and the Far East. These regulations will be implemented over the next ten years and will have serious implications for the refining industry. The purpose of this paper is to describe an alternative approach to desulfurization based on the recent advances in biotechnology and to outline the progress which has been made in recent years in this area. Biocatalytic Desulfurization (BDS) is not a commercial technology, but conceptual engineering and sensitivity analyses have shown that the approach has great promise. Several Government, University and Industrial groups are working now to develop the technology. The recent advances which have resulted from the application of the new tools of biotechnology to the problem have accelerated the development effort, and the first commercial BDS units may be available in 1996.

  1. Studies involving high temperature desulfurization/regeneration reactions of metal oxides for fuel cell development. Final report

    SciTech Connect

    Jalan, V.

    1983-10-01

    Research conducted at Giner, Inc. during 1981 to 1983 under the present contract has been a continuation of the investigation of a high temperature regenerable desulfurization process capable of reducing the sulfur content in coal gases from 200 ppM to 1 ppM. The overall objective has been the integration of a coal gasifier with a molten carbonate fuel cell, which requires that the sulfur content be below 1 ppM. Commercially available low temperature processes incur an excessive energy penalty. Results obtained with packed-bed and fluidized bed reactors have demonstrated that a CuO/ZnO mixed oxide sorbent is regenerable and capable of lowering the sulfur content (as H/sub 2/S and COS) from 200 ppM in simulated hot coal-derived gases to below 1 ppM level at 600 to 650/sup 0/C. Four potential sorbents (copper, tungsten oxide, vanadium oxide and zinc oxide) were initially selected for experimental use in hot regenerable desulfurization in the temperature range 500 to 650/sup 0/C. Based on engineering considerations, such as desulfurization capacity in per weight or volume of sorbents, a coprecipitated CuO/ZnO was selected for further study. A structural reorganization mechanism, unique to mixed oxides, was identified: the creation of relatively fine crystallites of the sulfided components (Cu/sub 2/S and ZnS) to counteract the loss of surface area due to sintering during regeneration. Studies with 9 to 26% water vapor in simulated coal gases show that sulfur levels below 1 ppM can be achieved in the temperature range of 500/sup 0/ to 650/sup 0/C. The ability of CuO/ZnO to remove COS, CS/sub 2/ and CH/sub 3/SH at these conditions has been demonstrated in this study. Also a previously proposed pore-plugging model was further developed with good success for data treatment of both packed bed and fluidized-bed reactors. 96 references, 42 figures, 21 tables.

  2. Studies of in-situ calcium-based sorbents in advanced pressurized coal conversion systems

    SciTech Connect

    Katta, S.; Shires, P.J.; O'Donnell, J.J.

    1992-01-01

    The overall objective of the project is to obtain experimental data on the reactions of calcium-based sorbents in gasification systems and to evaluate or develop kinetic models applicable to the commercial design of such systems. Both air-blown coal gasification systems and second generation fluid bed combustion systems (partial gasification) will be investigated, as well as subsequent stabilization of the solid wastes (calcium sulfide/ash) produced. More specifically, the objectives are to: Develop data on kinetics of in-situ desulfurization reactions; study the effect of calcium on the kinetics of carbon conversion rate; study kinetics of oxidation of CaS to CaSO[sup 4]; Develop and identify viable techniques to stabilize CaS; and, carry out further development work on most promising method and determine its commercial economics.

  3. Studies of in-situ calcium-based sorbents in advanced pressurized coal conversion systems

    SciTech Connect

    Katta, S.; Shires, P.J.; O`Donnell, J.J.

    1992-11-01

    The overall objective of the project is to obtain experimental data on the reactions of calcium-based sorbents in gasification systems and to evaluate or develop kinetic models applicable to the commercial design of such systems. Both air-blown coal gasification systems and second generation fluid bed combustion systems (partial gasification) will be investigated, as well as subsequent stabilization of the solid wastes (calcium sulfide/ash) produced. More specifically, the objectives are to: Develop data on kinetics of in-situ desulfurization reactions; study the effect of calcium on the kinetics of carbon conversion rate; study kinetics of oxidation of CaS to CaSO{sup 4}; Develop and identify viable techniques to stabilize CaS; and, carry out further development work on most promising method and determine its commercial economics.

  4. CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

    SciTech Connect

    David A. Green; Brian S. Turk; Jeffrey W. Portzer; Raghubir P.Gupta; William J. McMichael; Ya Liang; Douglas P. Harrison

    2002-10-01

    The objective of this project is to develop a simple and inexpensive process to separate CO{sub 2} as an essentially pure stream from a fossil fuel combustion system using a regenerable sorbent. The sorbents being investigated in this project are primarily alkali carbonates, and particularly sodium carbonate and potassium carbonate, which are converted to bicarbonates through reaction with carbon dioxide and water vapor. Bicarbonates are regenerated to carbonates when heated, producing a nearly pure CO{sub 2} stream after condensation of water vapor. This quarter, electrobalance tests suggested that higher temperature calcination of trona leds to reduced carbonation activity in subsequent cycles, but that calcination in dry carbon dioxide did not result in decreased activity relative to calcination in helium. Following higher temperature calcination, sodium bicarbonate (SBC) No.3 has greater activity than either coarse or fine grades of trona. Fixed bed testing of calcined SBC No.3 at 70 C confirmed that high rates of carbon dioxide absorption are possible and that the resulting product is a mixture of Wegscheider's salt and sodium carbonate. In fluidized bed testing of supported potassium carbonate, very rapid carbonation rates were observed. Activity of the support material complicated the data analysis. A milled, spherical grade of SBC appeared to be similar in attrition and abrasion characteristics to an unmilled, less regularly shaped SBC. The calcination behavior, at 107 C, for the milled and unmilled materials was also similar.

  5. Land application uses of dry FGD by-products: Quarterly report, October--December 1994

    SciTech Connect

    Beeghly, J.H.; Dick, W.A.; Haefner, R.J.

    1995-02-01

    The project involves the testing of several ground application uses for flue gas desulfurization by-products, including the mitigation of acid mine drainage, agronomic liming, cattle feedlot, stabilization of coal refuse, and road embankments. The project also involves ground water monitoring, environmental modeling, and economic modeling. This quarterly report deals mostly with the financial aspects of the research project. Monthly progress reports from various sites are included.

  6. Stabilization and/or regeneration of spent sorbents from coal gasification. Technical report, September 1--November 30, 1991

    SciTech Connect

    Abbasian, J.

    1991-12-31

    The objective of this investigation is to determine the effects of SO{sub 2} partial pressure and reaction temperature on the conversion of sulfide containing solid wastes from coal gasifiers to stable and environmentally acceptable calcium-sulfate, while preventing the release of sulfur dioxide through undesirable side reactions during the stabilization step. An additional objective of this program is to investigate the use of the Spent Sorbent Regeneration Process (SSRP) to regenerate spent limestone, from a fluidized-bed gasifier with in-bed sulfur capture, for recycling to the gasifier. To achieve these objectives, selected samples of partially sulfided sorbents will be reacted with oxygen at a variety of operating conditions under sufficient SO{sub 2} partial pressure to prevent release of sulfur from the solids during stabilization that reduces the overall sorbent utilization. Partially sulfided limestone will also be regenerated with water to produce calcium hydroxide and release sulfur as H{sub 2}S. The regenerated sorbent will be dewatered, dried and pelletized. The reactivity of the regenerated sorbent toward H{sub 2}S will also be determined. During this quarter sulfidation tests were conducted in a quartz fluidized-bed reactor in which the selected calcium-based sorbents were first calcined and then were reacted with hydrogen sulfide at ambient pressure and 1650{degree}F. These tests were conducted with each sorbent in two particle sizes. Chemical analyses of the partially sulfided sorbents indicate that the extent of sulfidation was in the range of 40--50%. The partially sulfided material will be reacted with oxygen to determine the effects of temperature and SO{sub 2} partial pressure on the stabilization of the calcium sulfide in solid waste materials. 23 refs., 1 fig., 2 tabs.

  7. Red soil as a regenerable sorbent for high temperature removal of hydrogen sulfide from coal gas.

    PubMed

    Ko, Tzu-Hsing; Chu, Hsin; Lin, Hsiao-Ping; Peng, Ching-Yu

    2006-08-25

    In this study, hydrogen sulfide (H(2)S) was removed from coal gas by red soil under high temperature in a fixed-bed reactor. Red soil powders were collected from the northern, center and southern of Taiwan. They were characterized by XRPD, porosity analysis and DCB chemical analysis. Results show that the greater sulfur content of LP red soils is attributed to the higher free iron oxides and suitable sulfidation temperature is around 773K. High temperature has a negative effect for use red soil as a desulfurization sorbent due to thermodynamic limitation in a reduction atmosphere. During 10 cycles of regeneration, after the first cycle the red soil remained stable with a breakthrough time between 31 and 36 min. Hydrogen adversely affects sulfidation reaction, whereas CO exhibits a positive effect due to a water-shift reaction. COS was formed during the sulfidation stage and this was attributed to the reaction of H(2)S and CO. Results of XRPD indicated that, hematite is the dominant active species in fresh red soil and iron sulfide (FeS) is a product of the reaction between hematite and hydrogen sulfide in red soils. The spinel phase FeAl(2)O(4) was found during regeneration, moreover, the amount of free iron oxides decreased after regeneration indicating the some of the free iron oxide formed a spinel phase, further reducting the overall desulfurization efficiency.

  8. Sorbent Structural Impacts Due to Humidity on Carbon Dioxide Removal Sorbents for Advanced Exploration Systems

    NASA Technical Reports Server (NTRS)

    Watson, David; Knox, James C.; West, Phillip; Stanley, Christine M.; Bush, Richard

    2015-01-01

    The Life Support Systems Project (LSSP) under the Advanced Exploration Systems (AES) program builds upon the work performed under the AES Atmosphere Resource Recovery and Environmental Monitoring (ARREM) project focusing on the numerous technology development areas. The CO2 removal and associated air drying development efforts are focused on improving the current state-of-the-art system on the International Space Station (ISS) utilizing fixed beds of sorbent pellets by seeking more robust pelletized sorbents, evaluating structured sorbents, and examining alternate bed configurations to improve system efficiency and reliability. A component of the CO2 removal effort encompasses structural stability testing of existing and emerging sorbents. Testing will be performed on dry sorbents and sorbents that have been conditioned to three humidity levels. This paper describes the sorbent structural stability screening efforts in support of the LSS Project within the AES Program.

  9. High temperature sorbents for oxygen

    NASA Technical Reports Server (NTRS)

    Sharma, Pramod K. (Inventor)

    1994-01-01

    A sorbent capable of removing trace amounts of oxygen (ppt) from a gas stream at a high temperature above 200 C comprising a porous alumina silicate support, such as zeolite, containing from 1 to 10 percent by weight of ion exchanged transition metal, such as copper or cobalt ions, and 0.05 to 1.0 percent by weight of an activator selected from a platinum group metal such as platinum is described. The activation temperature, oxygen sorption, and reducibility are all improved by the presence of the platinum activator.

  10. MERCURIC CHLORIDE CAPTURE BY ALKALINE SORBENTS

    EPA Science Inventory

    The paper gives results of bench-scale mechanistic studies of mercury/sorbent reactions that showed that mercuric chloride (HgC12) is readily adsorbed by alkaline sorbents, which may offers a less expensive alternative to the use of activated carbons. A laboratory-scale, fixed-b...

  11. PRODUCTION OF CONSTRUCTION AGGREGATES FROM FLUE GAS DESULFURIZATION SLUDGE

    SciTech Connect

    1998-12-01

    Through a cooperative agreement with DOE, the Research and Development Department of CONSOL Inc. (CONSOL R and D) is teaming with SynAggs, Inc. and Duquesne Light to design, construct, and operate a 500 lb/h continuous pilot plant to produce road construction aggregate from a mixture of wet flue gas desulfurization (FGD) sludge, fly ash, and other components. The proposed project is divided into six tasks: (1) Project Management; (2) Mix Design Evaluation; (3) Process Design; (4) Construction; (5) Start-Up and Operation; and (6) Reporting. In this quarter, Tasks 1 and 2 were completed. A project management plan (Task 1) was issued to DOE on October 22, 1998 . The mix design evaluation (Task 2) with Duquesne Light Elrama Station FGD sludge and Allegheny Power Hatfields Ferry Station fly ash was completed. Eight semi-continuous bench-scale tests were conducted to examine the effects of mix formulation on aggregate properties. A suitable mix formulation was identified to produce aggregates that meet specifications of the American Association of State High Transport Officials (AASHTO) as Class A aggregate for use in highway construction. The mix formulation was used in designing the flow sheet of the pilot plant. The process design (Task 3) is approximately 80% completed. Equipment was evaluated to comply with design requirements. The design for the curing vessel was completed by an outside engineering firm. All major equipment items for the pilot plant, except the curing vessel, were ordered. Pilot plant construction (Task 4) was begun in October. The Hazardous Substance Plan was issued to DOE. The Allegheny County (PA) Heat Department determined that an air emission permit is not required for operation of the pilot plant.

  12. Summary and assessment of METC zinc ferrite hot coal gas desulfurization test program, final report: Volume 2, Appendices

    SciTech Connect

    Underkoffler, V.S.

    1986-12-01

    The Morgantown Energy Technology Center (METC) has conducted a test program to develop a zinc ferrite-based high temperature desulfurization process which could be applied to fuel gas entering downstream components such as molten carbonate fuel cells or gas turbines. As a result of prior METC work with iron oxide and zinc oxide sorbents, zinc ferrite evolved as a candidate with the potential for high capacity, low equilibrium levels of H/sub 2/S, and structural stability after multiple regenerations. The program consisted of laboratory-scale testing with a two-inch diameter reactor and simulated fixed-bed gasifier gas; bench-scale testing with a six-inch diameter reactor and actual gas from the METC 42-inch fixed bed gasifier; as well as laboratory-scale testing of zinc ferrite with simulated fluidized bed gasifier gas. Data from sidestream testing are presented. 18 refs.

  13. Production of elemental sulfur and methane from H{sub 2}S and CO{sub 2} derived from a coal desulfurization process. Annual technical progress report, October 1, 1995--September 30, 1996; Quarterly technical progress report, July 1--September 30, 1996

    SciTech Connect

    Jiang, X.; Khang, S.J.; Keener, T.C.

    1996-12-31

    This annual report summarizes the results of the project during the third year period. The purpose of this study was to develop an experimental and theoretical procedure to investigate the feasibility of producing elemental sulfur, carbon monoxide, hydrogen and possibly methane from hydrogen sulfide and carbon dioxide through catalytic reactions. A standard experimental system that can evaluate potential catalysts under controlled laboratory conditions has been designed and constructed. And an effective simulation program capable of providing valuable thermodynamic information on the reaction system has been compiled. During this project year, the modified experimental system for the catalytic reaction studies was installed and the temperature distribution profile inside the reactor has been characterized. New flowmeters were replaced in the reaction system and calibrated to control the flowrates of H{sub 2}S, CO{sub 2}, H{sub 2} and N{sub 2}. Based on the experimental results of H{sub 2}S decomposition under both non-catalytic and catalytic conditions, bench scale experiments were performed with the CoO-MoO{sub 3}-Alumina catalyst at moderate temperatures, around 550 C, to investigate the adsorption effects using solid sorbents within a sulfur vapor environment. Four kinds of adsorbents have been tested. In addition to the above baseline tests, several designs of solid adsorbent feed system have been tested. Under both an inert and a real reaction environment, bench scale experiments were performed to investigate the characteristics and efficiency of activated carbon passing through the CoO-MoO{sub 3}-Alumina catalyst bed.

  14. A DFT study of the extractive desulfurization mechanism by [BMIM](+)[AlCl4](-) ionic liquid.

    PubMed

    Li, Hongping; Chang, Yonghui; Zhu, Wenshuai; Jiang, Wei; Zhang, Ming; Xia, Jiexiang; Yin, Sheng; Li, Huaming

    2015-05-14

    In this work, the interaction nature between [BMIM](+)[AlCl4](-) ionic liquid (IL) and aromatic sulfur compounds (thiophene, benzothiophene, and dibenzothiophene) has been studied by means of density functional theory (M06-2X functional) combined with an implicit solvation model. Although [BMIM](+)[AlCl4](-) is a metal-containing IL, its extractive desulfurization mechanism is different from other metal-containing ILs but similar to non-metal-containing ILs. Important reactions involved in extractive desulfurization (EDS) were systematically studied. Our results have demonstrated that both the cation and the anion play important roles in EDS. On the basis of the structure analysis, reduced density gradient analaysis (RDG), and energy decomposition analysis, [BMIM](+) cation affords a π-π interaction while [AlCl4](-) anion provides a hydrogen bonding interaction. Electrostatic potential analysis implies the dominant π-π interaction and hydrogen bonding interaction are driven by electrostatic interaction between IL and aromatic sulfur compounds. Interaction energy between [BMIM](+)[AlCl4](-) and thiophene (TH), benzothiophene (BT), and dibenzothiophene (DBT) follows the order TH < BT < DBT. Moreover, Al-containing IL with a high molar ratio of AlCl3 ([BMIMCl]/2[AlCl3]) has also been studied. Results show that [Al2Cl7](-) species will be formed with excess AlCl3. However, the [Al2Cl7](-)-based IL cannot improve the EDS performance. Improvement of EDS performance with a high molar ratio of AlCl3 is credited to the Lewis acidity of AlCl3. Charge analysis reveals that there is no obvious charge transfer during the reaction, which is different from Fe-containing ILs as well as solid sorbents. In addition, CH-π interaction is not important for the current system.

  15. Ultrafine pyrite desulfurization by selective flocculation

    SciTech Connect

    Cai, Z.; Liu, H.; Wu, J.; Wang, X.

    1997-12-31

    Selective flocculation is introduced for the separation of ultrafine pyrite from coal. Selective flocculation refers to the process in which high molecule weight polymer reagents bridge the fine particles of one component in a mixture. According to the differences in physico-chemical properties, the reagent can be adsorbed on one component which can be flocculated but not on others which cannot be flocculated. A number of selective flocculation separation tests under different conditions have been performed and the results are very encouraging. The results also show that desulfurization and deashing can be obtained simultaneously in the selective flocculation process.

  16. Microbial stabilization of sulfur-landen sorbents; Technical report, September 1--November 30, 1993

    SciTech Connect

    Miller, K.W.

    1993-12-31

    Clean coal technologies that involve limestone for sulfur capture generate lime/limestone products laden with sulfur at various oxidation states. If sulfur is completely stabilized as sulfate, the spent sorbent is ready for commercial utilization as gypsum. However, the presence of reduced sulfur species requires additional processing. Thermal oxidation of reduced sulfur can result in undesirable release of SO{sub 2}. Microbial oxidation might provide an inexpensive and effective alternative. Sorbents laden with reduced forms of sulfur such as sulfide, sulfite, or various polythionate species serve as growth substrates for sulfur-oxidizing bacteria, which have the potential to convert all sulfur to sulfate. This quarter, efforts focused on determining the combined effects of dibasic acids (DBA) and Ca{sup +2} concentration on several strains of neutrophilic thiobacilli, including Thiobacillus neapolitanus ATCC 23639 and ATCC 23641, and an isolate, TQ1, which was obtained from a commercial sulfur dioxide scrubber that utilizes DBA.

  17. Effects of surface acidities of MCM-41 modified with MoO3 on adsorptive desulfurization of gasoline

    NASA Astrophysics Data System (ADS)

    Shao, Xinchao; Zhang, Xiaotong; Yu, Wenguang; Wu, Yuye; Qin, Yucai; Sun, Zhaolin; Song, Lijuan

    2012-12-01

    A series of MCM-41 samples containing molybdenum oxide as active species in the mesoporous channels loaded by spontaneous monolayer dispersion (SMD) and impregnation (IM) have been prepared and characterized using XRD, N2 adsorption-desorption analysis, Fourier transform infrared spectroscopy (FTIR) and intelligent gravimetric analyzer (IGA). The relative number of hydroxy on the adsorbents was investigated by in situ FTIR. Surface acidities of the adsorbents were studied by infrared spectroscopy of adsorbed pyridine and correlated with reactivity for adsorptive desulfurization. The IGA technique was employed to investigate adsorption behavior of thiophene and benzene on the adsorbents at 303 K. It is shown that MoO3 can be highly dispersed up to 0.2 g g-1 in the MCM-41 channels by the SMD strategy with the ordered mesoporous structure of the MoMM samples remaining intact. The ordered mesostructure of MCM-41 is, however, destroyed at higher MoO3 contents of 0.26 and 0.32 g g-1 with particle sizes of 1.2 nm and 3.6 nm, respectively, observed. For the MoMI(0.2) sample prepared by the IM method, the aggregation of the MoO3 particles takes place with a particle size of 6.5 nm obtained. The results are also revealed that the dispersion extent of the MoO3 species is related to the abundant surface hydroxy of MCM-41. The host species and guest species undergo solid-state reaction to form Sisbnd Osbnd Mo bonds in the mixtures which enhance both the Lewis acid and Brönsted acid of the samples. It has been concluded that the surface acidities of the sorbents contributes to the desulfurization performance which has also been investigated in this study. The octahedral coordinated species (Mo7O246-) are the adsorptive active species for desulfurization compared with the tetrahedral coordinated ones (MoO42-).

  18. High-temperature desulfurization of gasifier effluents with rare earth and rare earth/transition metal oxides

    SciTech Connect

    Dooley, Kerry M.; Kalakota, Vikram; Adusumilli, Sumana

    2011-02-11

    We have improved the application of mixed rare-earth oxides (REOs) as hot gas desulfurization adsorbents by impregnating them on stable high surface area supports and by the inclusion of certain transition metal oxides. We report comparative desulfurization experiments at high temperature (900 K) using a synthetic biomass gasifier effluent containing 0.1 vol % H2S, along with H2, CO2, and water. More complex REO sorbents outperform the simpler CeO2/La2O3 mixtures, in some cases significantly. Supporting REOs on Al2O3 (~20 wt % REO) or ZrO2 actually increased the sulfur capacities found after several cycles on a total weight basis. Another major increase in sulfur capacity took place when MnOx or FeOx is incorporated. Apparently most of the Mn or Fe is dispersed on or near the surface of the mixed REOs because the capacities with REOs greatly exceeded those of Al2O3-supported MnOx or FeOx alone at these conditions. In contrast, incorporating Cu has little effect on sulfur adsorption capacities. Both the REO and transition metal/REO adsorbents could be regenerated completely using air for at least five repetitive cycles.

  19. Removal of hazardous gaseous pollutants from industrial flue gases by a novel multi-stage fluidized bed desulfurizer.

    PubMed

    Mohanty, C R; Adapala, Sivaji; Meikap, B C

    2009-06-15

    Sulfur dioxide and other sulfur compounds are generated as primary pollutants from the major industries such as sulfuric acid plants, cupper smelters, catalytic cracking units, etc. and cause acid rain. To remove the SO(2) from waste flue gas a three-stage counter-current multi-stage fluidized bed adsorber was developed as desulfurization equipment and operated in continuous bubbling fluidization regime for the two-phase system. This paper represents the desulfurization of gas mixtures by chemical sorption of sulfur dioxide on porous granular calcium oxide particles in the reactor at ambient temperature. The advantages of the multi-stage fluidized bed reactor are of high mass transfer and high gas-solid residence time that can enhance the removal of acid gas at low temperature by dry method. Experiments were carried out in the bubbling fluidization regime supported by visual observation. The effects of the operating parameters such as sorbent (lime) flow rate, superficial gas velocity, and the weir height on SO(2) removal efficiency in the multistage fluidized bed are reported. The results have indicated that the removal efficiency of the sulfur dioxide was found to be 65% at high solid flow rate (2.0 kg/h) corresponding to lower gas velocity (0.265 m/s), wier height of 70 mm and SO(2) concentration of 500 ppm at room temperature.

  20. Molecular biological enhancement of coal desulfurization: Cloning and expression of the sulfoxide/sulfone/sulfonate/sulfate genes in Pseudomonads and Thiobacillae

    SciTech Connect

    Krawiec, S.

    1990-10-22

    Research continued on coal desulfurization and the study of biological enhancement of desulfurization. This quarters work included: crosses between soil isolates containing r68.45 and P. aeruginosa 27853-2a; extents of crosses and abundances of transconjugants; purpose of repeated crosses; noteworthy features of mating protocol; phenotypic peculiarities and phenotypic stabilities of transconjugants; characterization of antibiotic sensitivity; effect of receiving R68.45 from P. putida PRS 2003; transfer of R68.45 from C18 to auxotrophs derived from P. aeruginosa 27853; and differences in ability of various soil isolates to transfer Dbt{sup +} phenotype to recipient cells; incipient characterizations of Thiobacillae spp. growth and antibiotic sensitivity; plasmid isolation; and acquisition of new soil isolates.

  1. Sorbents for the oxidation and removal of mercury

    DOEpatents

    Olson, Edwin S; Holmes, Michael J; Pavlish, John Henry

    2013-08-20

    A promoted activated carbon sorbent is described that is highly effective for the removal of mercury from flue gas streams. The sorbent comprises a new modified carbon form containing reactive forms of halogen and halides. Optional components may be added to increase reactivity and mercury capacity. These may be added directly with the sorbent, or to the flue gas to enhance sorbent performance and/or mercury capture. Mercury removal efficiencies obtained exceed conventional methods. The sorbent can be regenerated and reused. Sorbent treatment and preparation methods are also described. New methods for in-flight preparation, introduction, and control of the active sorbent into the mercury contaminated gas stream are described.

  2. Sorbents for the oxidation and removal of mercury

    DOEpatents

    Olson, Edwin S.; Holmes, Michael J.; Pavlish, John Henry

    2014-09-02

    A promoted activated carbon sorbent is described that is highly effective for the removal of mercury from flue gas streams. The sorbent comprises a new modified carbon form containing reactive forms of halogen and halides. Optional components may be added to increase reactivity and mercury capacity. These may be added directly with the sorbent, or to the flue gas to enhance sorbent performance and/or mercury capture. Mercury removal efficiencies obtained exceed conventional methods. The sorbent can be regenerated and reused. Sorbent treatment and preparation methods are also described. New methods for in-flight preparation, introduction, and control of the active sorbent into the mercury contaminated gas stream are described.

  3. Sorbents for the oxidation and removal of mercury

    DOEpatents

    Olson, Edwin S.; Holmes, Michael J.; Pavlish, John H.

    2012-05-01

    A promoted activated carbon sorbent is described that is highly effective for the removal of mercury from flue gas streams. The sorbent comprises a new modified carbon form containing reactive forms of halogen and halides. Optional components may be added to increase reactivity and mercury capacity. These may be added directly with the sorbent, or to the flue gas to enhance sorbent performance and/or mercury capture. Mercury removal efficiencies obtained exceed conventional methods. The sorbent can be regenerated and reused. Sorbent treatment and preparation methods are also described. New methods for in-flight preparation, introduction, and control of the active sorbent into the mercury contaminated gas stream are described.

  4. Sorbents for the oxidation and removal of mercury

    DOEpatents

    Olson, Edwin S.; Holmes, Michael J.; Pavlish, John H.

    2008-10-14

    A promoted activated carbon sorbent is described that is highly effective for the removal of mercury from flue gas streams. The sorbent comprises a new modified carbon form containing reactive forms of halogen and halides. Optional components may be added to increase reactivity and mercury capacity. These may be added directly with the sorbent, or to the flue gas to enhance sorbent performance and/or mercury capture. Mercury removal efficiencies obtained exceed conventional methods. The sorbent can be regenerated and reused. Sorbent treatment and preparation methods are also described. New methods for in-flight preparation, introduction, and control of the active sorbent into the mercury contaminated gas stream are described.

  5. Preparation of Modified Semi-Coke–Supported ZnFe2O4 Sorbent with the Assistance of Ultrasonic Irradiation

    PubMed Central

    Mi, Jie; Ren, Jun; Zhang, Yongyan

    2012-01-01

    Abstract Modified semi-coke (MSC) supported ZnFe2O4 was prepared under the condition of ultrasonic irradiation. Performance of the sorbents was tested using a fixed-bed reactor as a hot gas desulfurizer. The MSC support, the mass ratio of zinc ferrites to the support, calcination temperature, and the ultrasonic conditions of power and time all had influences on the structure and the breakthrough behavior of the sorbent. Ultrasonic irradiation can help to make ZnFe2O4 highly dispersed on MSC. ZnFe2O4/MSC had increased porosity and a larger specific surface area compared to unsupported ZnFe2O4. The sorbent exhibited a higher sulfur capacity at the optimum preparing conditions, where the mass ratio of ZnFe2O4 to MSC was 8:10, calcinated at 500°C, and the ultrasonic power and time was 900 W and 1.5 h, respectively. PMID:23133310

  6. Preparation of Modified Semi-Coke-Supported ZnFe(2)O(4) Sorbent with the Assistance of Ultrasonic Irradiation.

    PubMed

    Mi, Jie; Ren, Jun; Zhang, Yongyan

    2012-11-01

    Modified semi-coke (MSC) supported ZnFe(2)O(4) was prepared under the condition of ultrasonic irradiation. Performance of the sorbents was tested using a fixed-bed reactor as a hot gas desulfurizer. The MSC support, the mass ratio of zinc ferrites to the support, calcination temperature, and the ultrasonic conditions of power and time all had influences on the structure and the breakthrough behavior of the sorbent. Ultrasonic irradiation can help to make ZnFe(2)O(4) highly dispersed on MSC. ZnFe(2)O(4)/MSC had increased porosity and a larger specific surface area compared to unsupported ZnFe(2)O(4). The sorbent exhibited a higher sulfur capacity at the optimum preparing conditions, where the mass ratio of ZnFe(2)O(4) to MSC was 8:10, calcinated at 500°C, and the ultrasonic power and time was 900 W and 1.5 h, respectively.

  7. Investigation of mixed metal sorbent/catalysts for the simultaneous removal of sulfur and nitrogen oxides. Semiannual report, Apr 1, 1998--Oct 31, 1998

    SciTech Connect

    Dr. Ates Akyurtlu; Dr. Jale F. Akyurtlu

    1998-10-31

    Simultaneous removal of SO{sub 2} and NO{sub x} using a regenerable solid sorbent will constitute an important improvement over the use of separate processes for the removal of these two pollutants from stack gases and possibly eliminate several shortcomings of the individual SO{sub 2} and NO{sub x} removal operations. The work done at PETC and the DOE-funded investigation of the investigators on the sulfation and regeneration of alumina-supported cerium oxide sorbents have shown that they can perform well at relatively high temperatures (823--900 K) as regenerable desulfurization sorbents. Survey of the recent literature shows that addition of copper oxide to ceria lowers the sulfation temperature of ceria down to 773 K, sulfated ceria-based sorbents can function as selective SCR catalysts even at elevated temperatures, SO{sub 2} can be directly reduced to sulfur by CO on CuO-ceria catalysts, and ceria-based catalysts may have a potential for selective catalytic reduction of NO{sub x} by methane. These observations indicate a possibility of developing a ceria-based sorbent/catalyst which can remove both SO{sub 2} and NO{sub x} from flue gases within a relatively wide temperature window, produce significant amounts of elemental sulfur during regeneration, and use methane for the selective catalytic reduction of NO{sub x}. The objective of this research is to conduct kinetic and parametric studies of the selective catalytic reduction of NO{sub x} with NH{sub 3} and CH{sub 4} over alumina-supported cerium oxide and copper oxide-cerium oxide sorbent/catalysts; investigate SO{sub 2} removal at lower temperatures by supported copper oxide-cerium oxide sorbents; and investigate the possibility of elemental sulfur production during regeneration with CO or with CH{sub 4} air mixtures. The sorbents consisting of cerium oxide and copper oxide impregnated on alumina have been prepared and characterized. Their sulfation performance has been investigated in a TGA setup

  8. Ultrasound-promoted chemical desulfurization of Illinois coals

    SciTech Connect

    Chao, S.S.

    1991-01-01

    The overall objectives of the program were to investigate the use of ultrasound to promote coal desulfurization reactions and to evaluate chemical coal desulfurization schemes under mild conditions through a fundamental understanding of their reaction mechanisms and kinetics. The ultimate goal was to develop an economically feasible mild chemical process to reduce the total sulfur content of Illinois Basin Coals, while retaining their original physical characteristics, such as calorific value and volatile matter content. During the program, potential chemical reactions with coal were surveyed under various ultrasonic irradiation conditions for desulfurization, to formulate preliminary reaction pathways, and to select a few of the more promising chemical processes for more extensive study.

  9. A NOVEL APPROACH TO CATALYTIC DESULFURIZATION OF COAL

    SciTech Connect

    John G. Verkade

    1998-08-31

    The nonionic superbase P(MeNCH{sub 2}CH{sub 2}){sub 3}N (A) efficiently desulfurizes trisulfides to disulfides and monosulfides, disulfides to monosulfides, and propylene sulfide to propene. S=P(MeNCH{sub 2}CH{sub 2}){sub 3}N (B) was formed as the sulfur acceptor. P(NMe{sub 2}){sub 3} was a much poorer desulfurizing agent than A under the same reaction conditions. Thiocyanates and triphenylphosphine sulfide were also desulfurized with A, but N-(phenylthio)phthalimide formed [A-SP]{sup +} phthalimide in quantitative yield.

  10. Selenium speciation in flue desulfurization residues.

    PubMed

    Zhong, Liping; Cao, Yan; Li, Wenying; Xie, Kechang; Pan, Wei-Ping

    2011-01-01

    Flue gas from coal combustion contains significant amounts of volatile selenium (Se). The capture of Se in the flue gas desulfurization (FGD) scrubber unit has resulted in a generation of metal-laden residues. It is important to determine Se speciation to understand the environmental impact of its disposal. A simple method has been developed for selective inorganic Se(IV), Se(VI) and organic Se determination in the liquid-phase FGD residues by hydride generation atomic fluorescence spectrometry (AFS). It has been determined that Se(IV), Se(VI) and organic Se can be accurately determined with detection limits (DL) of 0.05, 0.06 and 0.06 microg/L, respectively. The accuracy of the proposed method was evaluated by analyzing the certified reference material, NIST CRM 1632c, and also by analyzing spiked tap-water samples. Analysis indicates that the concentration of Se is high in FGD liquid residues and primarily exists in a reduced state as selenite (Se(IV)). The toxicity of Se(IV) is the strongest of all Se species. Flue gas desulfurization residues pose a serious environmental risk.

  11. Biocatalytic desulfurization (BDS) of petrodiesel fuels.

    PubMed

    Mohebali, Ghasemali; Ball, Andrew S

    2008-08-01

    Oil refineries are facing many challenges, including heavier crude oils, increased fuel quality standards, and a need to reduce air pollution emissions. Global society is stepping on the road to zero-sulfur fuel, with only differences in the starting point of sulfur level and rate reduction of sulfur content between different countries. Hydrodesulfurization (HDS) is the most common technology used by refineries to remove sulfur from intermediate streams. However, HDS has several disadvantages, in that it is energy intensive, costly to install and to operate, and does not work well on refractory organosulfur compounds. Recent research has therefore focused on improving HDS catalysts and processes and also on the development of alternative technologies. Among the new technologies one possible approach is biocatalytic desulfurization (BDS). The advantage of BDS is that it can be operated in conditions that require less energy and hydrogen. BDS operates at ambient temperature and pressure with high selectivity, resulting in decreased energy costs, low emission, and no generation of undesirable side products. Over the last two decades several research groups have attempted to isolate bacteria capable of efficient desulfurization of oil fractions. This review examines the developments in our knowledge of the application of bacteria in BDS processes, assesses the technical viability of this technology and examines its future challenges.

  12. Sorption of methylxanthines by different sorbents

    NASA Astrophysics Data System (ADS)

    Dmitrienko, S. G.; Andreeva, E. Yu.; Tolmacheva, V. V.; Terent'eva, E. A.

    2013-05-01

    Sorption of caffeine, theophylline, theobromine, diprophylline, and pentoxyphylline on different sorbents (supercross-linked polystyrene, surface-modified copolymer of styrene and divinylbenzene Strata-X, and carbon nanomaterials Taunit and Diasorb-100-C16T) was studied in a static mode in an effort to find new sorbents suitable for sorption isolation and concentration of methylxanthines. The peculiarities of sorption of methylxanthines were explained in relation to the solution acidity, the nature of the sorbates and their concentration, the nature of the solvent, and the structural characteristics of the sorbents.

  13. Investigation and Demonstration of Dry Carbon-Based Sorbent Injection for Mercury Control

    SciTech Connect

    Jason Ruhl; Justin Smith; Sharon Sjostrom; Sheila Haythorthwaite; Terry Hunt

    1997-08-01

    The U.S. Department of Energy (DOE) issued Public Service Company of Colorado (PSCO) a cost sharing contract to evaluate carbon-based sorbents for mercury control on a 600 acfm laboratory-scale particulate control module (PCM). The PCM can be configured as simulate an electrostatic precipitator, a pulse-jet fabric filter, or a reverse-gas fabric filter and is installed on an operating coal-fired power plant. Three different dry carbon-based sorbents were tested this quarter to determine their mercury removal capability in the different configurations. The project is currently in the seventh quarter of an eight-quarter Phase I project. Testing in all configurations is nearly complete. Original plans included the use of an on-line mercury analyzer to collect test data. However, due to very low baseline mercury concentration, on-line measurement did not provide accurate data. The project used a modified MESA method grab sample technique to determine inlet and outlet mercury concentrations. A major concern during sorbent evaluations was the natural ability of the flyash at the test site to remove mercury. This often made determination of sorbent only mercury removal difficult. The PCM was configured as a reverse-gas baghouse and brought online with "clean" flue gas on March 10* at an A/C of 2.0 ft/min. The dustcake forms the filtering media in a reverse gas baghouse. In the absence of flyash, the bags were precoated with a commercially available alumina silicate material to form an inert dustcake. Some baseline tests were completed with clean gas for comparison to clean gas pulse jet tests. The PCM was reconfigured as a TOXECON unit in April 1997 with testing completed in May 1997. TOXECON, an EPIU patented technology, is a pulse-jet baghouse operating at a high A/C ratio downstream of a primary particulate colIector with sorbent injection upstream of the baghouse for air toxics removal. Mercury removals of O to 97o/0 were obtained depending on test conditions.

  14. Stabilization of spent sorbents from coal-based power generation processes. Technical report, September 1, 1995--November 30,1995

    SciTech Connect

    Abbassian, J.; Hill, A.H.

    1995-12-31

    The overall objective of this study is to determine the effect of implementation of the new and more stringent EPA Protocol Test Method involving sulfide containing waste, on the suitability of the oxidized spent sorbents from gasification of of high sulfur coals for disposal in landfills, and to determine the optimum operating conditions in a ``final`` hydrolysis stage for conversion of the residual calcium sulfide in these wastes to materials that are suitable for disposal in landfills. An additional objective is to study the effect of ash on the regeneration and ash-sorbent separation steps in the Spent Sorbent Regeneration Process (SSRP). To achieve these objectives, a large set of oxidized samples of sulfided calcium-based sorbents (produced in earlier ICCI-funded programs) as well as oxidized samples of gasifier discharge (containing ash and spent sorbent) are tested according to the new EPA test protocol. Samples of the oxidized spent sorbents that do not pass the EPA procedure are reacted with water and carbon dioxide to convert the residual calcium sulfide to calcium carbonate. During this quarter, samples of oxidized sulfided calcium-based sorbents, including untreated calcium sulfide-containing feed materials, were analyzed using both weak acid and more stringent strong acid tests. Preliminary analysis of the H{sub 2}S leachability test results indicate that all samples (including those that were not oxidized) pass the EPA requirement of 500 mg H{sub 2}S per kg of solid waste. However, under the strong acid test procedure, samples containing more than 2.5% calcium sulfide fail the EPA requirement.

  15. Replacement of charcoal sorbent in the VOST

    SciTech Connect

    Johnson, L.D.; Fuerst, R.G.; Foster, A.L.; Bursey, J.T.

    1993-01-01

    EPA Method 0030, the Volatile Organic Sampling Train (VOST), for sampling volatile organics from stationary sources, specifies the use of petroleum-base charcoal in the second sorbent tube. Charcoal has proven to be a marginal performer as a sampling sorbent, partly due to inconsistency in analyte recovery. In addition, commercial availability of petroleum charcoal for VOST tubes has been variable. Lack of data on comparability and variability of charcoals for VOST application has created uncertainty when other charcoals are substituted. Five potential sorbent replacements for charcoal in Method 0030 were evaluated along with a reference charcoal. Two of the sorbents tested, Ambersorb XE-340 and Tenax GR, did not perform well enough to qualify as replacements. Three candidates, Anasorb 747, Carbosieve S-III and Kureha Beaded Activated Charcoal, performed adequately, and produced statistically equivalent results. Anasorb 747 appears to be an acceptable replacement for petroleum charcoal, based on a combination of performance, availability, and cost.

  16. Production of ultra-low-sulfur gasoline: an equilibrium and kinetic analysis on adsorption of sulfur compounds over Ni/MMS sorbents.

    PubMed

    Subhan, Fazle; Liu, B S; Zhang, Q L; Wang, W S

    2012-11-15

    High performance nickel-based micro-mesoporous silica (Ni/MMS) sorbent was prepared by incipient wetness impregnation with ultrasonic aid (IWI-u) for adsorptive desulfurization (ADS) of commercial gasoline and simulated fuels. The sorbents were characterized with BET, XRD, TPR, SEM, HRTEM and TG/DTG. These results show that 20 wt%Ni/MMS (IWI-u) can still retain the framework of MMS and nickel particles were homogeneously distributed in the MMS channels without any aggregation, which improved significantly the ADS performance of the sorbents. The studies on the ADS kinetics indicate that the adsorption behavior of thiophene (T), benzothiophene (BT) and dibenzothiophene (DBT) over 20 wt%Ni/MMS (IWI-u) can be described appropriately by pseudo second-order kinetic model. The intraparticle diffusion model verified that the steric hindrance and intraparticle diffusion were the rate controlling step of the adsorption process of DBT molecules. Langmuir model can be used to describe the adsorption isotherms for T, BT and DBT due to low coverage. The regeneration sorbent maintains the sulfur removal efficiency of 85.9% for 6 cycles.

  17. Production of ultra-low-sulfur gasoline: an equilibrium and kinetic analysis on adsorption of sulfur compounds over Ni/MMS sorbents.

    PubMed

    Subhan, Fazle; Liu, B S; Zhang, Q L; Wang, W S

    2012-11-15

    High performance nickel-based micro-mesoporous silica (Ni/MMS) sorbent was prepared by incipient wetness impregnation with ultrasonic aid (IWI-u) for adsorptive desulfurization (ADS) of commercial gasoline and simulated fuels. The sorbents were characterized with BET, XRD, TPR, SEM, HRTEM and TG/DTG. These results show that 20 wt%Ni/MMS (IWI-u) can still retain the framework of MMS and nickel particles were homogeneously distributed in the MMS channels without any aggregation, which improved significantly the ADS performance of the sorbents. The studies on the ADS kinetics indicate that the adsorption behavior of thiophene (T), benzothiophene (BT) and dibenzothiophene (DBT) over 20 wt%Ni/MMS (IWI-u) can be described appropriately by pseudo second-order kinetic model. The intraparticle diffusion model verified that the steric hindrance and intraparticle diffusion were the rate controlling step of the adsorption process of DBT molecules. Langmuir model can be used to describe the adsorption isotherms for T, BT and DBT due to low coverage. The regeneration sorbent maintains the sulfur removal efficiency of 85.9% for 6 cycles. PMID:23022413

  18. Plane flame furnace combustion tests on JPL desulfurized coal

    NASA Technical Reports Server (NTRS)

    Reuther, J. J.; Kim, H. T.; Lima, J. G. H.

    1982-01-01

    The combustion characteristics of three raw bituminous (PSOC-282 and 276) and subbituminous (PSOC-230) coals, the raw coals partially desulfurized (ca -60%) by JPL chlorinolysis, and the chlorinated coals more completely desulfurized (ca -75%) by JPL hydrodesulfurization were determined. The extent to which the combustion characteristics of the untreated coals were altered upon JPL sulfur removal was examined. Combustion conditions typical of utility boilers were simulated in the plane flame furnace. Upon decreasing the parent coal voltaile matter generically by 80% and the sulfur by 75% via the JPL desulfurization process, ignition time was delayed 70 fold, burning velocity was retarded 1.5 fold, and burnout time was prolonged 1.4 fold. Total flame residence time increased 2.3 fold. The JPL desulfurization process appears to show significant promise for producing technologically combustible and clean burning (low SO3) fuels.

  19. Sorbent Injection for Small ESP Mercury Control in Low Sulfur Eastern Bituminous Coal Flue Gas

    SciTech Connect

    Carl Richardson; Katherine Dombrowski; Douglas Orr

    2006-12-31

    This project Final Report is submitted to the U.S. Department of Energy (DOE) as part of Cooperative Agreement DE-FC26-03NT41987, 'Sorbent Injection for Small ESP Mercury Control in Low Sulfur Eastern Bituminous Coal Flue Gas.' Sorbent injection technology is targeted as the primary mercury control process on plants burning low/medium sulfur bituminous coals equipped with ESP and ESP/FGD systems. About 70% of the ESPs used in the utility industry have SCAs less than 300 ft2/1000 acfm. Prior to this test program, previous sorbent injection tests had focused on large-SCA ESPs. This DOE-NETL program was designed to generate data to evaluate the performance and economic feasibility of sorbent injection for mercury control at power plants that fire bituminous coal and are configured with small-sized electrostatic precipitators and/or an ESP-flue gas desulfurization (FGD) configuration. EPRI and Southern Company were co-funders for the test program. Southern Company and Reliant Energy provided host sites for testing and technical input to the project. URS Group was the prime contractor to NETL. ADA-ES and Apogee Scientific Inc. were sub-contractors to URS and was responsible for all aspects of the sorbent injection systems design, installation and operation at the different host sites. Full-scale sorbent injection for mercury control was evaluated at three sites: Georgia Power's Plant Yates Units 1 and 2 [Georgia Power is a subsidiary of the Southern Company] and Reliant Energy's Shawville Unit 3. Georgia Power's Plant Yates Unit 1 has an existing small-SCA cold-side ESP followed by a Chiyoda CT-121 wet scrubber. Yates Unit 2 is also equipped with a small-SCA ESP and a dual flue gas conditioning system. Unit 2 has no SO2 control system. Shawville Unit 3 is equipped with two small-SCA cold-side ESPs operated in series. All ESP systems tested in this program had SCAs less than 250 ft2/1000 acfm. Short-term parametric tests were conducted on Yates Units 1 and 2 to evaluate

  20. Alkylated benzothiophene desulfurization by Rhodococcus sp. strain T09.

    PubMed

    Matsui, T; Onaka, T; Tanaka, Y; Tezuka, T; Suzuki, M; Kurane, R

    2000-03-01

    A benzothiophene desulfurizing bacterium was isolated and identified as Rhodococcus sp. strain T09. Growth assays revealed that this strain assimilated, as the sole sulfur source, various organosulfur compounds that cannot be assimilated by the well-studied dibenzothiophene-desulfurizing Rhodococcus sp. IGTS8. The cellular growth rate of strain T09 for the alkylated benzothiophenes depended on the alkylated position and the length of the alkyl moiety.

  1. Demonstration of the carbon-sulfur bond targeted desulfurization of benzothiophene by thermophilic Paenibacillus sp. strain A11-2 capable of desulfurizing dibenzothiophene.

    PubMed

    Konishi, J; Onaka, T; Ishii, Y; Suzuki, M

    2000-06-15

    Paenibacillus sp. strain A11-2, which had been primarily isolated as a bacterial strain capable of desulfurizing dibenzothiophene to produce 2-hydroxybiphenyl at high temperatures, was found to desulfurize benzothiophene more efficiently than dibenzothiophene. The desulfurized product was identified as o-hydroxystyrene by GC-MS and 1H-NMR analysis. Benzothiophene was assumed to be degraded in a way analogous to the 4S pathway, which has been well-known as a mode of dibenzothiophene degradation. These results suggest that benzothiophene desulfurization may share at least partially the reaction mechanism with dibenzothiophene desulfurization.

  2. Apparatus for hot-gas desulfurization of fuel gases

    DOEpatents

    Bissett, Larry A.

    1992-01-01

    An apparatus for removing sulfur values from a hot fuel gas stream in a fdized bed contactor containing particulate sorbent material by employing a riser tube regeneration arrangement. Sulfur-laden sorbent is continuously removed from the fluidized bed through a stand pipe to the riser tube and is rapidly regenerated in the riser tube during transport of the sorbent therethrough by employing an oxygen-containing sorbent regenerating gas stream. The riser tube extends from a location below the fluidized bed to an elevation above the fluidized bed where a gas-solid separating mechanism is utilized to separate the regenerated particulate sorbent from the regeneration gases and reaction gases so that the regenerated sorbent can be returned to the fluidized bed for reuse.

  3. Continuous fluidized-bed contactor with recycle of sorbent

    DOEpatents

    Scott, Charles D.; Petersen, James N.; Davison, Brian H.

    1996-01-01

    A continuous fluidized-bed contactor containing sorbent particles is used to remove solutes from liquid solvents. As the sorbent particles, for example gel beads, sorb the solute, for example metal ion species, the sorbent particles tend to decrease in diameter. These smaller loaded sorbent particles rise to the top of the contactor, as larger sorbent particles remain at the bottom of the contactor as a result of normal hydraulic forces. The smaller loaded sorbent particles are then recovered, regenerated, and reintroduced into the contactor. Alternatively, the loaded sorbent particles may also slightly increase in diameter, or exhibit no change in diameter but an increase in density. As a result of normal hydraulic forces the larger loaded sorbent particles fall to the bottom of the contactor. The larger loaded sorbent particles are then recovered, regenerated, and reintroduced into the contactor.

  4. Continuous fluidized-bed contactor with recycle of sorbent

    DOEpatents

    Scott, C.D.; Petersen, J.N.; Davison, B.H.

    1996-07-09

    A continuous fluidized-bed contactor containing sorbent particles is used to remove solutes from liquid solvents. As the sorbent particles, for example gel beads, sorb the solute, for example metal ion species, the sorbent particles tend to decrease in diameter. These smaller loaded sorbent particles rise to the top of the contactor, and larger sorbent particles remain at the bottom of the contactor as a result of normal hydraulic forces. The smaller loaded sorbent particles are then recovered, regenerated, and reintroduced into the contactor. Alternatively, the loaded sorbent particles may also slightly increase in diameter, or exhibit no change in diameter but an increase in density. As a result of normal hydraulic forces the larger loaded sorbent particles fall to the bottom of the contactor. The larger loaded sorbent particles are then recovered, regenerated, and reintroduced into the contactor. 8 figs.

  5. INVESTIGATION AND DEMONSTRATION OF DRY CARBON-BASED SORBENT INJECTION FOR MERCURY CONTROL

    SciTech Connect

    Terry Hunt; Mark Fox; Lillian Stan; Sheila Haythornthwaite; Justin Smith; Jason Ruhl

    1998-10-01

    This quarterly report describes the activities that have taken place during the first full quarter of the Phase II project ''Investigation and Demonstration of Dry Carbon-Based Sorbent Injection for Mercury Control''. Modifications were completed and sampling began at the 600 acfm pilot-scale particulate control module (PCM) located at the Comanche Station in Pueblo, CO. The PCM was configured as an electrostatic precipitator for these tests. A Perkin-Elmer flue gas mercury analyzer was installed on-site and operated. Initial test results using both manual sampling methodology and the mercury analyzer are presented herein. Preparations were made during this period for full-scale mercury testing of several PSCo units. A site visit was made to Arapahoe and Cherokee Generating Stations to determine sample locations and to develop a test plan.

  6. Dewatering of flue gas desulfurization sulfite solids

    SciTech Connect

    Garrison, F.C.; Wells, W.L.

    1984-06-12

    The dewatering capabilities of sulfite sludges from flue gas desulfurization facilities are substantially improved by the addition of relatively small amounts of sodium thiosulfate additive, or additives derived from or related to sodium thiosulfate, into the scrubber slurry liquor. As an added embellishment, these predetermined amounts of said additives are greater than those required for effecting substantial scale inhibition in the scrubber innards. Subsequently, conventional dewatering of the sulfite sludge to about 80 to 90 percent solids directly produces a waste product disposable in both an economically and an environmentally acceptable manner, in that the thixotropic characteristics of such sludges which are associated therewith upwards to about 70 percent solids therein are completely eliminated.

  7. Studies involving high temperature desulfurization/regeneration reactions of metal oxides for fuel cell development

    NASA Astrophysics Data System (ADS)

    Jalan, V.

    1983-10-01

    A high temperature regenerable desulfurization process capable of reducing the sulfur content in coal gases from 200 pp to 1 ppm was investigated to provide for the integration of a coal gasifier with a molten carbonate fuel cell, which requires that the sulfur content be below 1 ppm. Results obtained with packed-bed and fluidized-bed reactors have demonstrated that a CuO/ZnO mixed oxide sorbent is regenerble and capable of lowering the sulfur content (as H2s and COS) from 200 ppm in simulated hot coal-derived gases to below 1 ppm level at 600 to 650 C. A comprecipitated CuO/ZnO was elected for further study. A structural reorganization mechanism, unique to mixed oxides, was identified: the creation of relatively fine crystallites of the sulfide components (Cu2S and ZnS) to counteract the loss of surface area due to sintering during regeneration. Studies with 9 to 26% water vapor in simulated coal gases show that sulfur levels below 1 ppm can be achieved in the temperature range of 500 to 650 C. The ability of CuO/ZnO to remove COS, CS2 and CH3SH at these conditions was demonstrated. A previously proposed pore-plugging model was further developed with good success for data treatment of both packed-bed and fluidized-bed reactors.

  8. Land application uses for dry flue gas desulfurization by-products: Phase 2. Final report

    SciTech Connect

    Stehouwer, R.; Dick, W.; Bigham, J.

    1998-03-01

    The Clean Air Act, as amended in 1990, spurred the development of flue gas desulfurization (FGD) technologies, several of which produce a dry, solid by-product material consisting of excess sorbent, reaction products containing sulfates and sulfites, and coal fly ash. A three-phase study was initiated in December 1990 to demonstrate high-volume beneficial uses of FGD by-products as alternates to landfilling. Phase 1 characterized the chemical, physical, mineralogical, and engineering properties of FGD by-products from 13 coal-fired boilers, and provided a preliminary evaluation of the economic feasibility of various FGD by-product applications. This report covers Phase 2 of the study, which included (1) laboratory and greenhouse studies to evaluate the use of dry FGD by-products as a soil conditioning amendment for acidic minespoils and agricultural soils, (2) field studies to test several high-volume agronomic and engineering uses, and (3) development and preliminary application of a basic methodological framework for estimation of the economic costs and benefits to society of various beneficial reuse options.

  9. Developing clean fuels: Novel techniques for desulfurization

    NASA Astrophysics Data System (ADS)

    Nehlsen, James P.

    The removal of sulfur compounds from petroleum is crucial to producing clean burning fuels. Sulfur compounds poison emission control catalysts and are the source of acid rain. New federal regulations require the removal of sulfur in both gasoline and diesel to very low levels, forcing existing technologies to be pushed into inefficient operating regimes. New technology is required to efficiently produce low sulfur fuels. Two processes for the removal of sulfur compounds from petroleum have been developed: the removal of alkanethiols by heterogeneous reaction with metal oxides; and oxidative desulfurization of sulfides and thiophene by reaction with sulfuric acid. Alkanethiols, common in hydrotreated gasoline, can be selectively removed and recovered from a hydrocarbon stream by heterogeneous reaction with oxides of Pb, Hg(II), and Ba. The choice of reactive metal oxides may be predicted from simple thermodynamic considerations. The reaction is found to be autocatalytic, first order in water, and zero order in thiol in the presence of excess oxide. The thiols are recovered by reactive extraction with dilute oxidizing acid. The potential for using polymer membrane hydrogenation reactors (PEMHRs) to perform hydrogenation reactions such as hydrodesulfurization is explored by hydrogenating ketones and olefins over Pt and Au group metals. The dependence of reaction rate on current density suggests that the first hydrogen addition to the olefin is the rate limiting step, rather than the adsorption of hydrogen, for all of the metals tested. PEMHRs proved unsuccessful in hydrogenating sulfur compounds to perform HDS. For the removal of sulfides, a two-phase reactor is used in which concentrated sulfuric acid oxidizes aromatic and aliphatic sulfides present in a hydrocarbon solvent, generating sulfoxides and other sulfonated species. The polar oxidized species are extracted into the acid phase, effectively desulfurizing the hydrocarbon. A reaction scheme is proposed for this

  10. Study on multiphase flow and mixing in semidry flue gas desulfurization with a multifluid alkaline spray generator using particle image velocimetry

    SciTech Connect

    Zhou, Y.G.; Wang, D.F.; Zhang, M.C.

    2009-06-15

    Particle image velocimetry (PIV) technique was used to measure the velocity fields of gas-droplet-solid multiphase flow in the experimental setup of a novel semidry flue gas desulfurization process with a multifluid alkaline spray generator. The flow structure, mixing characteristic, and interphase interaction of gas-droplet-solid multiphase flow were investigated both in the confined alkaline spray generator and in the duct bent pipe section. The results show that sorbent particles in the confined alkaline spray generator are entrained into the spray core zone by a high-speed spray jet and most of the sorbent particles can be effectively humidified by spray water fine droplets to form aqueous lime slurry droplets. Moreover, a minimum amount of air stream in the generator is necessary to achieve higher collision humidification efficiency between sorbent particles and spray water droplets and to prevent the possible deposition of fine droplets on the wall. The appropriate penetration length of the slurry droplets from the generator can make uniform mixing between the formed slurry droplets and main air stream in the duct bent pipe section, which is beneficial to improving sulfur dioxide removal efficiency and to preventing the deposition of droplets on the wall.

  11. FIELD TEST PROGRAM FOR EVALUATION OF SORBENT INJECTION FOR MERCURY CONTROL

    SciTech Connect

    Sharon Sjostrom

    2004-02-12

    The power industry in the U.S. is faced with meeting new regulations to reduce the emissions of mercury compounds from coal-fired plants. These regulations are directed at the existing fleet of nearly 1,100 boilers. These plants are relatively old with an average age of over 40 years. Although most of these units are capable of operating for many additional years, there is a desire to minimize large capital expenditures because of the reduced (and unknown) remaining life of the plant to amortize the project. Injecting a sorbent such as powdered activated carbon into the flue gas represents one of the simplest and most mature approaches to controlling mercury emissions from coal-fired boilers. The overall objective of this test program described in this quarterly report is to evaluate the capabilities of activated carbon injection at four plants with configurations that together represent 78% of the existing coal-fired generation plants. This technology was successfully evaluated in NETL's Phase I tests at scales up to 150 MW, on plants burning subbituminous and bituminous coals and with ESPs and fabric filters. The tests also identified issues that still need to be addressed, such as evaluating performance on other configurations, optimizing sorbent usage (costs), and gathering longer term operating data to address concerns about the impact of activated carbon on plant equipment and operations. The four sites identified for testing are Sunflower Electric's Holcomb Station, AmerenUE's Meramec Station, AEP's Conesville Station, and Ontario Power Generation's Nanticoke Station. This is the first quarterly report for this project. This report includes an overview of the plans for the project. Field testing is scheduled to begin next quarter. In general, quarterly reports will be used to provide project overviews, project status, and technology transfer information. Topical reports will be prepared to present detailed technical information.

  12. CARBON DIOXIDE CAPTURE FROM FLUE GAS USING DRY REGENERABLE SORBENTS

    SciTech Connect

    David A. Green; Brian S. Turk; Raghubir P. Gupta; Douglas P. Harrison; Ya Liang

    2001-10-01

    The objective of this project is to develop a simple, inexpensive process to separate CO{sub 2} as an essentially pure stream from a fossil fuel combustion system using a regenerable, sodium-based sorbent. The sorbent being used in this project is sodium carbonate which is converted to sodium bicarbonate, ''baking soda,'' through reaction with carbon dioxide and water vapor. Sodium bicarbonate is regenerated to sodium carbonate when heated, producing a nearly pure CO{sub 2} stream after condensation of water vapor. Testing conducted previously confirmed that the reaction rate and achievable CO{sub 2} capacity of sodium carbonate decreased with increasing temperature, and that the global rate of reaction of sodium carbonate to sodium bicarbonate increased with an increase in both CO{sub 2} and H{sub 2}O concentrations. Energy balance calculations indicated that the rate of heat removal from the particle surface may determine the reaction rate for a particular particle system. This quarter, thermogravimetric analyses (TGA) were conducted which indicated that calcination of sodium bicarbonate at temperatures as high as 200 C did not cause a significant decrease in activity in subsequent carbonation testing. When sodium bicarbonate was subjected to a five cycle calcination/carbonation test, activity declined slightly over the first two cycles but was constant thereafter. TGA tests were also conducted with two other potential sorbents. Potassium carbonate was found to be less active than sodium carbonate, at conditions of interest in preliminary TGA tests. Sodium carbonate monohydrate showed negligible activity. Testing was also conducted in a 2-inch internal diameter quartz fluidized-bed reactor system. A five cycle test demonstrated that initial removals of 10 to 15 percent of the carbon dioxide in a simulated flue gas could be achieved. The carbonation reaction proceeded at temperatures as low as 41 C. Future work by TGA and in fixed-bed, fluidized-bed, and transport

  13. Method of removing hydrogen sulfide from gases utilizing a zinc oxide sorbent and regenerating the sorbent

    DOEpatents

    Jalan, Vinod M.; Frost, David G.

    1984-01-01

    A spent solid sorbent resulting from the removal of hydrogen sulfide from a fuel gas flow is regenerated with a steam-air mixture. The mixture of steam and air may also include additional nitrogen or carbon dioxide. The gas mixture contacts the spent sorbent containing metal sulfide at a temperature above 500.degree. C. to regenerate the sulfide to metal oxide or carbonate. Various metal species including the period four transition metals and the lanthanides are suitable sorbents that may be regenerated by this method. In addition, the introduction of carbon dioxide gas permits carbonates such as those of strontium, barium and calcium to be regenerated. The steam permits regeneration of spent sorbent without formation of metal sulfate. Moreover, the regeneration will proceed with low oxygen concentrations and will occur without the increase in temperature to minimize the risk of sintering and densification of the sorbent.

  14. Regenerable Sorbent for CO2 Removal

    NASA Technical Reports Server (NTRS)

    Alptekin, Gokhan; Jayaraman, Ambal

    2013-01-01

    A durable, high-capacity regenerable sorbent can remove CO2 from the breathing loop under a Martian atmosphere. The system design allows near-ambient temperature operation, needs only a small temperature swing, and sorbent regeneration takes place at or above 8 torr, eliminating the potential for Martian atmosphere to leak into the regeneration bed and into the breathing loop. The physical adsorbent can be used in a metabolic, heat-driven TSA system to remove CO2 from the breathing loop of the astronaut and reject it to the Martian atmosphere. Two (or more) alternating sorbent beds continuously scrub and reject CO2 from the spacesuit ventilation loop. The sorbent beds are cycled, alternately absorbing CO2 from the vent loop and rejecting the adsorbed material into the environment at a high CO2 partial pressure (above 8 torr). The system does not need to run the adsorber at cryogenic temperatures, and uses a much smaller temperature swing. The sorbent removes CO2 via a weak chemical interaction. The interaction is strong enough to enable CO2 adsorption even at 3 to 7.6 torr. However, because the interaction between the surface adsorption sites and the CO2 is relatively weak, the heat input needed to regenerate the sorbent is much lower than that for chemical absorbents. The sorbent developed in this project could potentially find use in a large commercial market in the removal of CO2 emissions from coal-fired power plants, if regulations are put in place to curb carbon emissions from power plants.

  15. The antimicrobial efficiency of silver activated sorbents

    NASA Astrophysics Data System (ADS)

    Đolić, Maja B.; Rajaković-Ognjanović, Vladana N.; Štrbac, Svetlana B.; Rakočević, Zlatko Lj.; Veljović, Đorđe N.; Dimitrijević, Suzana I.; Rajaković, Ljubinka V.

    2015-12-01

    This study is focused on the surface modifications of the materials that are used for antimicrobial water treatment. Sorbents of different origin were activated by Ag+-ions. The selection of the most appropriate materials and the most effective activation agents was done according to the results of the sorption and desorption kinetic studies. Sorption capacities of selected sorbents: granulated activated carbon (GAC), zeolite (Z), and titanium dioxide (T), activated by Ag+-ions were following: 42.06, 13.51 and 17.53 mg/g, respectively. The antimicrobial activity of Ag/Z, Ag/GAC and Ag/T sorbents were tested against Gram-negative bacteria E. coli, Gram-positive bacteria S. aureus and yeast C. albicans. After 15 min of exposure period, the highest cell removal was obtained using Ag/Z against S. aureus and E. coli, 98.8 and 93.5%, respectively. Yeast cell inactivation was unsatisfactory for all three activated sorbents. The antimicrobial pathway of the activated sorbents has been examined by two separate tests - Ag+-ions desorbed from the activated surface to the aqueous phase and microbial cell removal caused by the Ag+-ions from the solid phase (activated surface sites). The results indicated that disinfection process significantly depended on the microbial-activated sites interactions on the modified surface. The chemical state of the activating agent had crucial impact to the inhibition rate. The characterization of the native and modified sorbents was performed by X-ray diffraction technique, X-ray photoelectron spectroscopy and scanning electron microscope. The concentration of adsorbed and released ions was determined by inductively coupled plasma optical emission spectroscopy and mass spectrometry. The antimicrobial efficiency of activated sorbents was related not only to the concentration of the activating agent, but moreover on the surface characteristics of the material, which affects the distribution and the accessibility of the activating agent.

  16. Desulfurization of coal with hydroperoxides of vegetable oils. Technical progress report, March 1--May 31, 1995

    SciTech Connect

    Smith, G.V.; Gaston, R.D.; Song, R.; Cheng, J.; Shi, Feng; Gholson, K.L.

    1995-12-31

    This project proposes a new method for removing organic sulfur from Illinois coals using readily available farm products. It proposes to use air and vegetable oils to disrupt the coal matrix, oxidize sulfur forms, increase volatiles, and desulfurize coal. This will be accomplished by impregnating coals with polyunsaturated oils, converting the oils to their hydroperoxides, and heating. Since these oils are relatively inexpensive and easily applied, this project could lead to a cost effective method for removing organic sulfur from coals. Moreover, the oils are environmentally safe; they will produce no noxious products and will improve burning qualities of solid products. Preliminary experiments showed that IBC 104 coal catalyzes the formation of hydroperoxides in safflower oil and that more sulfur is extracted from the treated than untreated coal. During the first quarter the requirement of an added photosensitizer was eliminated, the catalytic effect of coal was confirmed, and the existence of a complex set of reactions was revealed. During the second quarter, working with IBC-108 coal (2.3% organic S, 0.4% pyrite S), the effects of different extraction solvents were examined. A new pretreatment which combines alkali with linseed oil was discovered. Best organic sulfur removal is approximately 26% using alkali pretreatment combined with linseed oil at 100[degrees]C. BTU loses can be kept to a minimum of 3% with proper use of solvents. During this third quarter the effects of different ratios of oil:coal, different temperatures, and different reaction times were completely examined. The effects of alkali on sulfur removal were further investigated. Best organic sulfur removal reaches 34% using ammonia pretreatment, then oil and finally aqNA2CO3 extraction.

  17. Soil washing enhancement with solid sorbents

    SciTech Connect

    El-Shoubary, Y.M.; Woodmansee, D.E.

    1996-12-31

    Soil washing is a dynamic, physical process that remediates contaminated soil through two mechanisms: particle size separation and transfer of the contaminant into the (mostly) liquid stream. The performance of different sorbents and additives to remove motor oil from sea sand was tested. Hydrocyclone, attrition scrubber, and froth flotation equipment were used for the decontamination study. Sorbents and additives were mixed with soils in the attrition scrubber prior to flotation. Sorbents used were granular activated carbon, powder activated carbon, and rubber tires. Chemical additives used were calcium hydroxide, sodium carbonate, Alconox{reg_sign}, Triton{reg_sign} X-100 and Triton{reg_sign} X-114. When a froth flotation run was performed using no additive, washed soils {open_quotes}tails{close_quotes} contained 4000 ppm of total oil and grease (TOG). However, when carbon or rubber (6% by weight) was added to the contaminated soils the washed soils {open_quotes}tails{close_quotes} contained 4000 ppm of total oil and grease (TOG). The addition of sodium carbonate or calcium hydroxide (6% by weight) had same effects as sorbents. In both cases washed soil {open_quotes}tails{close_quotes} contained total oil and grease of less than 1000 ppm. The use of these non-hazardous additives or sorbent can enhance the soil washing process and consequently saves on time (residence time in equipment design) required to achieve the target clean up levels. 18 refs., 12 figs.

  18. Aquatic oil spill cleanup using natural sorbents.

    PubMed

    Paulauskienė, Tatjana; Jucikė, Indrė

    2015-10-01

    One of the most popular transportation methods of crude oil is water transport, leading to potential spills of these pollutants in the seas and oceans and water areas of ports, during their extraction, transportation, transhipment and use. The growth of the Lithuanian economy and the expansion of competitiveness were hardly imagined without the development of the Klaipeda seaport. However, the intensity of shipping and the increase in cargo loading volumes at specialised terminals are associated with a higher risk of environmental pollution. To achieve a sustainable development of the seaport, it is necessary not only to ensure the prevention of potential water pollution but also, if necessary, to use environmentally friendly technology for pollution management. The work analyses the possibilities related to the collection of oil products from the water surface using natural sorbents (peat, wool, moss and straw) and their composites.The research of absorbed amount of crude oil and diesel fuel spilled on the water surface, while using sorbents and their composites, determined that sorbents' composite straw-peat (composition percentage of straw-peat 25-75 %) absorbs the major amount of both crude oil (60 % of the spilled volume) and diesel fuel (69 % of the spilled volume) comparing to single sorbents and sorbents' composite straw-peat (composition percentage of straw-peat 50-50 %).

  19. Aquatic oil spill cleanup using natural sorbents.

    PubMed

    Paulauskienė, Tatjana; Jucikė, Indrė

    2015-10-01

    One of the most popular transportation methods of crude oil is water transport, leading to potential spills of these pollutants in the seas and oceans and water areas of ports, during their extraction, transportation, transhipment and use. The growth of the Lithuanian economy and the expansion of competitiveness were hardly imagined without the development of the Klaipeda seaport. However, the intensity of shipping and the increase in cargo loading volumes at specialised terminals are associated with a higher risk of environmental pollution. To achieve a sustainable development of the seaport, it is necessary not only to ensure the prevention of potential water pollution but also, if necessary, to use environmentally friendly technology for pollution management. The work analyses the possibilities related to the collection of oil products from the water surface using natural sorbents (peat, wool, moss and straw) and their composites.The research of absorbed amount of crude oil and diesel fuel spilled on the water surface, while using sorbents and their composites, determined that sorbents' composite straw-peat (composition percentage of straw-peat 25-75 %) absorbs the major amount of both crude oil (60 % of the spilled volume) and diesel fuel (69 % of the spilled volume) comparing to single sorbents and sorbents' composite straw-peat (composition percentage of straw-peat 50-50 %). PMID:25994272

  20. Quarterly coal report

    SciTech Connect

    Young, P.

    1996-05-01

    The Quarterly Coal Report (QCR) provides comprehensive information about U.S. coal production, distribution, exports, imports, receipts, prices, consumption, and stocks to a wide audience, including Congress, Federal and State agencies, the coal industry, and the general public. Coke production, consumption, distribution, imports, and exports data are also provided. The data presented in the QCR are collected and published by the Energy Information Administration (EIA) to fulfill data collection and dissemination responsibilities as specified in the Federal Energy Administration Act of 1974 (Public Law 93-275), as amended. This report presents detailed quarterly data for October through December 1995 and aggregated quarterly historical data for 1987 through the third quarter of 1995. Appendix A displays, from 1987 on, detailed quarterly historical coal imports data, as specified in Section 202 of the Energy Policy and Conservation Amendments Act of 1985 (Public Law 99-58). Appendix B gives selected quarterly tables converted to metric tons.

  1. 6. Interior of quarters (executive officer's quarters), living room, looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Interior of quarters (executive officer's quarters), living room, looking west - Naval Air Station Chase Field, Quarters S, Essex Street, .45 mile South-Southeast of intersection of Texas State Highway 202 & Independence Street, Beeville, Bee County, TX

  2. 3. Southwest side of quarters (executive officer's quarters), looking northeast ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Southwest side of quarters (executive officer's quarters), looking northeast - Naval Air Station Chase Field, Quarters S, Essex Street, .45 mile South-Southeast of intersection of Texas State Highway 202 & Independence Street, Beeville, Bee County, TX

  3. 1. North side of quarters (executive officer's quarters), looking southeast ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. North side of quarters (executive officer's quarters), looking southeast - Naval Air Station Chase Field, Quarters S, Essex Street, .45 mile South-Southeast of intersection of Texas State Highway 202 & Independence Street, Beeville, Bee County, TX

  4. 4. South side of quarters (executive officer's quarters), looking north ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. South side of quarters (executive officer's quarters), looking north - Naval Air Station Chase Field, Quarters S, Essex Street, .45 mile South-Southeast of intersection of Texas State Highway 202 & Independence Street, Beeville, Bee County, TX

  5. 2. West side of quarters (executive officer's quarters), looking east ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. West side of quarters (executive officer's quarters), looking east - Naval Air Station Chase Field, Quarters S, Essex Street, .45 mile South-Southeast of intersection of Texas State Highway 202 & Independence Street, Beeville, Bee County, TX

  6. 5. East side of quarters (executive officer's quarters), looking west ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. East side of quarters (executive officer's quarters), looking west - Naval Air Station Chase Field, Quarters S, Essex Street, .45 mile South-Southeast of intersection of Texas State Highway 202 & Independence Street, Beeville, Bee County, TX

  7. Contextual view of quarters no. 2 quarters no. 1, and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Contextual view of quarters no. 2 quarters no. 1, and water tower, looking southwest. - Sacramento National Wildlife Refuge, Headquarters Complex, Quarters No. 2, 752 County Road 99W, Willows, Glenn County, CA

  8. Improving Enzyme Activity and Broadening Selectivity for Biological Desulfurization and Upgrading of Petroleum Feedstocks

    SciTech Connect

    Abhijeet P. Borole; Choo Y. Hamilton; Karen Miller; Brian Davison; Matthew Grossman; Robert Shong

    2003-05-12

    The objective of this project was to develop improved biocatalysts for desulfurization and upgrading of petroleum feedstocks. The goal was to improve the activity and broaden the selectivity of desulfurization enzymes using directed evolution as a tool as well as to explore the impact of ring-opening on biological desulfurization

  9. Sorbent Structural Testing on Carbon Dioxide Removal Sorbents for Advanced Exploration Systems

    NASA Technical Reports Server (NTRS)

    Watson, David; Knox, James C.; West, Phillip; Bush, Richard

    2016-01-01

    Long term space missions require carbon dioxide removal systems that can function with minimal downtime required for maintenance, low power consumption and maximum efficiency for CO2 removal. A major component of such a system are the sorbents used for the CO2 and desiccant beds. Sorbents must not only have adequate CO2 and H2O removal properties, but they must have the mechanical strength to prevent structural breakdown due to pressure and temperature changes during operation and regeneration, as well as resistance to breakdown due to moisture in the system from cabin air. As part of the studies used to select future CO2 sorbent materials, mechanical tests are performed on various zeolite sorbents to determine mechanical performance while dry and at various humidified states. Tests include single pellet crush, bulk crush and attrition tests. We have established a protocol for testing sorbents under dry and humid conditions, and previously tested the sorbents used on the International Space Station carbon dioxide removal assembly. This paper reports on the testing of a series of commercial sorbents considered as candidates for use on future exploration missions.

  10. A NOVEL APPROACH TO CATALYTIC DESULFURIZATION OF COAL

    SciTech Connect

    John G. Verkade

    2001-11-01

    Column chromatographic separation of the S=PBu{sub 3}/PBu{sub 3} product mixture followed by weighing the S=PBu{sub 3}, and by vacuum distillation of S=PBu{sub 3}/PBu{sub 3}mixture followed by gas chromatographic analysis are described. Effects of coal mesh size, pre-treatment with methanol Coal (S) + excess PR{sub 3} {yields} Coal + S=PR{sub 3}/PBu{sub 3} and sonication on sulfur removal by PBu{sub 3} revealed that particle size was not observed to affect desulfurization efficiency in a consistent manner. Coal pretreatment with methanol to induce swelling or the addition of a filter aid such as Celite reduced desulfurization efficiency of the PBu{sub 3} and sonication was no more effective than heating. A rationale is put forth for the lack of efficacy of methanol pretreatment of the coal in desulfurization runs with PBu{sub 3}. Coal desulfurization with PBu{sub 3} was not improved in the presence of miniscule beads of molten lithium or sodium as a desulfurizing reagent for SPBu{sub 3} in a strategy aimed at regenerating PBu{sub 3} inside coal pores. Although desulfurization of coals did occur in sodium solutions in liquid ammonia, substantial loss of coal mass was also observed. Of particular concern is the mass balance in the above reaction, a problem which is described in some detail. In an effort to solve this difficulty, a specially designed apparatus is described which we believe can solve this problem reasonably effectively. Elemental sodium was found to remove sulfur quantitatively from a variety of polycyclic organosulfur compounds including dibenzothiophene and benzothiophene under relatively mild conditions (150 C) in a hydrocarbon solvent without requiring the addition of a hydrogen donor. Lithium facilitates the same reaction at a higher temperature (254 C). Mechanistic pathways are proposed for these transformations. Curiously, dibenzothiophene and its corresponding sulfone was virtually quantitatively desulfurized in sodium solutions in liquid

  11. Sulfur tolerant highly durable CO.sub.2 sorbents

    DOEpatents

    Smirniotis, Panagiotis G.; Lu, Hong

    2012-02-14

    A sorbent for the capture of carbon dioxide from a gas stream is provided, the sorbent containing calcium oxide (CaO) and at least one refractory dopant having a Tammann temperature greater than about 530.degree. C., wherein the refractory dopant enhances resistance to sintering, thereby conserving performance of the sorbent at temperatures of at least about 530.degree. C. Also provided are doped CaO sorbents for the capture of carbon dioxide in the presence of SO.sub.2.

  12. Encapsulated liquid sorbents for carbon dioxide capture.

    PubMed

    Vericella, John J; Baker, Sarah E; Stolaroff, Joshuah K; Duoss, Eric B; Hardin, James O; Lewicki, James; Glogowski, Elizabeth; Floyd, William C; Valdez, Carlos A; Smith, William L; Satcher, Joe H; Bourcier, William L; Spadaccini, Christopher M; Lewis, Jennifer A; Aines, Roger D

    2015-02-05

    Drawbacks of current carbon dioxide capture methods include corrosivity, evaporative losses and fouling. Separating the capture solvent from infrastructure and effluent gases via microencapsulation provides possible solutions to these issues. Here we report carbon capture materials that may enable low-cost and energy-efficient capture of carbon dioxide from flue gas. Polymer microcapsules composed of liquid carbonate cores and highly permeable silicone shells are produced by microfluidic assembly. This motif couples the capacity and selectivity of liquid sorbents with high surface area to facilitate rapid and controlled carbon dioxide uptake and release over repeated cycles. While mass transport across the capsule shell is slightly lower relative to neat liquid sorbents, the surface area enhancement gained via encapsulation provides an order-of-magnitude increase in carbon dioxide absorption rates for a given sorbent mass. The microcapsules are stable under typical industrial operating conditions and may be used in supported packing and fluidized beds for large-scale carbon capture.

  13. Encapsulated liquid sorbents for carbon dioxide capture

    NASA Astrophysics Data System (ADS)

    Vericella, John J.; Baker, Sarah E.; Stolaroff, Joshuah K.; Duoss, Eric B.; Hardin, James O.; Lewicki, James; Glogowski, Elizabeth; Floyd, William C.; Valdez, Carlos A.; Smith, William L.; Satcher, Joe H.; Bourcier, William L.; Spadaccini, Christopher M.; Lewis, Jennifer A.; Aines, Roger D.

    2015-02-01

    Drawbacks of current carbon dioxide capture methods include corrosivity, evaporative losses and fouling. Separating the capture solvent from infrastructure and effluent gases via microencapsulation provides possible solutions to these issues. Here we report carbon capture materials that may enable low-cost and energy-efficient capture of carbon dioxide from flue gas. Polymer microcapsules composed of liquid carbonate cores and highly permeable silicone shells are produced by microfluidic assembly. This motif couples the capacity and selectivity of liquid sorbents with high surface area to facilitate rapid and controlled carbon dioxide uptake and release over repeated cycles. While mass transport across the capsule shell is slightly lower relative to neat liquid sorbents, the surface area enhancement gained via encapsulation provides an order-of-magnitude increase in carbon dioxide absorption rates for a given sorbent mass. The microcapsules are stable under typical industrial operating conditions and may be used in supported packing and fluidized beds for large-scale carbon capture.

  14. CONVERSION EXTRACTION DESULFURIZATION (CED) PHASE III

    SciTech Connect

    James Boltz

    2005-03-01

    This project was undertaken to refine the Conversion Extraction Desulfurization (CED) technology to efficiently and economically remove sulfur from diesel fuel to levels below 15-ppm. CED is considered a generic term covering all desulfurization processes that involve oxidation and extraction. The CED process first extracts a fraction of the sulfur from the diesel, then selectively oxidizes the remaining sulfur compounds, and finally extracts these oxidized materials. The Department of Energy (DOE) awarded Petro Star Inc. a contract to fund Phase III of the CED process development. Phase III consisted of testing a continuous-flow process, optimization of the process steps, design of a pilot plant, and completion of a market study for licensing the process. Petro Star and the Degussa Corporation in coordination with Koch Modular Process Systems (KMPS) tested six key process steps in a 7.6-centimeter (cm) (3.0-inch) inside diameter (ID) column at gas oil feed rates of 7.8 to 93.3 liters per hour (l/h) (2.1 to 24.6 gallons per hour). The team verified the technical feasibility with respect to hydraulics for each unit operation tested and successfully demonstrated pre-extraction and solvent recovery distillation. Test operations conducted at KMPS demonstrated that the oxidation reaction converted a maximum of 97% of the thiophenes. The CED Process Development Team demonstrated that CED technology is capable of reducing the sulfur content of light atmospheric gas oil from 5,000-ppm to less than 15-ppm within the laboratory scale. In continuous flow trials, the CED process consistently produced fuel with approximately 20-ppm of sulfur. The process economics study calculated an estimated process cost of $5.70 per product barrel. The Kline Company performed a marketing study to evaluate the possibility of licensing the CED technology. Kline concluded that only 13 refineries harbored opportunity for the CED process. The Kline study and the research team's discussions with

  15. Kinetics of the reaction of iron blast furnace slag/hydrated lime sorbents with SO{sub 2} at low temperatures: effects of the presence of CO{sub 2}, O{sub 2}, and NOx

    SciTech Connect

    Liu, C.F.; Shih, S.M.

    2009-09-15

    The effects of the presence of CO{sub 2}, O{sub 2}, and NOx in the flue gas on the kinetics of the sulfation of blast furnace slag/hydrated lime sorbents at low temperatures were studied using a differential fixed-bed reactor. When O{sub 2} and NOx were not present simultaneously, the reaction kinetics was about the same as that under the gas mixtures containing SO{sub 2}, H{sub 2}O, and N{sub 2} only, being affected mainly by the relative humidity. The sulfation of sorbents can be described by the surface coverage model and the model equations derived for the latter case. When both O{sub 2} and NOx, were present, the sulfation of sorbents was greatly enhanced, forming a great amount of sulfate in addition to sulfite. The surface coverage model is still valid in this case, but the model equations obtained show a more marked effect of relative humidity and negligible effects of SO{sub 2} concentration and temperature on the reaction. The effect of sorbent composition on the reaction kinetics was entirely represented by the effects of the initial specific surface area (S{sub g0}) and the Ca molar content (M{sup -1}) of sorbent. The initial conversion rate of sorbent increased linearly with increasing S{sub g0}, and the ultimate conversion increased linearly with increasing S{sub g0}M{sup -1}. The model equations obtained in this work are applicable to describe the kinetics of the sulfation of the sorbents in the low-temperature dry and semidry fine gas desulfurization processes either with an upstream NOx, removal unit or without.111

  16. Attrition resistant, zinc titanate-containing, reduced sulfur sorbents

    DOEpatents

    Vierheilig, Albert A.; Gupta, Raghubir P.; Turk, Brian S.

    2004-11-02

    The disclosure is directed to sorbent compositions for removing reduced sulfur species (e.g., H.sub.2 S, COS and CS.sub.2) a feed stream. The sorbent is formed from a multi-phase composition including a zinc titanate phase and a zinc oxide-aluminate phase. The sorbent composition is substantially free of unreacted alumina.

  17. Topical Report 5: Sorbent Performance Report

    SciTech Connect

    Krutka, Holly; Sjostrom, Sharon

    2011-05-31

    ADA-ES has completed an extensive sorbent screening program funded primarily through DOE NETL cooperative agreement DE-NT0005649 with support from EPRI and industry cost-share participants. Tests were completed on simulated and actual flue gas. The overall project objective is to address the viability and accelerate development of a solid-based postcombustion CO2 capture technology that can be retrofit to the existing fleet of coal-fired power plants. An important component of the viability assessment was to evaluate the state of development of sorbents and measure key performance characteristics under realistic operating conditions.

  18. Alkaline sorbent injection for mercury control

    DOEpatents

    Madden, Deborah A.; Holmes, Michael J.

    2003-01-01

    A mercury removal system for removing mercury from combustion flue gases is provided in which alkaline sorbents at generally extremely low stoichiometric molar ratios of alkaline earth or an alkali metal to sulfur of less than 1.0 are injected into a power plant system at one or more locations to remove at least between about 40% and 60% of the mercury content from combustion flue gases. Small amounts of alkaline sorbents are injected into the flue gas stream at a relatively low rate. A particulate filter is used to remove mercury-containing particles downstream of each injection point used in the power plant system.

  19. Alkaline sorbent injection for mercury control

    DOEpatents

    Madden, Deborah A.; Holmes, Michael J.

    2002-01-01

    A mercury removal system for removing mercury from combustion flue gases is provided in which alkaline sorbents at generally extremely low stoichiometric molar ratios of alkaline earth or an alkali metal to sulfur of less than 1.0 are injected into a power plant system at one or more locations to remove at least between about 40% and 60% of the mercury content from combustion flue gases. Small amounts of alkaline sorbents are injected into the flue gas stream at a relatively low rate. A particulate filter is used to remove mercury-containing particles downstream of each injection point used in the power plant system.

  20. Calcium silicate cement sorbent for H/sub 2/S removal and improved gasification processes. Annual progress report, October 1, 1981-September 30, 1982

    SciTech Connect

    Yoo, H.J.; Steinberg, M.

    1982-10-01

    Commercial calcium silicate bearing Portland cement type III (PC III), in the form of agglomerated cement sorbent (ACS) pellets, is being investigated for in-situ desulfurization of fuel gases and for improved coal gasification. The preparation procedure and conditions for pelletizing agglomerated cement sorbent (ACS) by a low energy, low cost agglomeration technique have been modified using a two-stage pelletization procedure, which yields ACS pellets of greater mechanical strength. A 40 mm ID bench scale fluidized bed gasifier (FBG) was used to determine sulfur removal efficiency of ACS pellets as well as their attrition resistance, using a simulated gas mixture. These tests show that 90% or more of the sulfur removal from the gas is achieved until 35% of the ACS pellet is sulfidated and that it has excellent attrition resistance (less than 0.1% wt loss) during cyclic tests excluding the first conditioning cycle. The gasification of coal by partial oxidation with air to low Btu gas was conducted in a 1-inch bench scale FBG unit by our collaborator, the Foster Wheeler Corporation (FWC). At temperatures between 800/sup 0/C and 950/sup 0/C the efficiency of coal gasification is improved by as much as 40% when ACS pellets are used compared to the use of Greer limestone. At the same time the sulfur removal efficiency is increased from 50 to 65% with Greer limestone to over 95% with the ACS pellets. The test on sulfur fixation characteristics of the sorbent in the 1-inch FBG unit using a simulated gas also shows that the ACS pellet is much more reactive toward H/sub 2/S than Greer limestone. The ability of ACS pellets to simultaneously desulfurize and improve the gasification efficiency of coal in FBG justifies further investigation.

  1. Biogas desulfurization using autotrophic denitrification process.

    PubMed

    Bayrakdar, Alper; Tilahun, Ebrahim; Calli, Baris

    2016-01-01

    The aim of this study was to evaluate the performance of an autotrophic denitrification process for desulfurization of biogas produced from a chicken manure digester. A laboratory scale upflow fixed bed reactor (UFBR) was operated for 105 days and fed with sodium sulfide or H2S scrubbed from the biogas and nitrate as electron donor and acceptor, respectively. The S/N ratio (2.5 mol/mol) of the feed solution was kept constant throughout the study. When the UFBR was fed with sodium sulfide solution with an influent pH of 7.7, about 95 % sulfide and 90 % nitrate removal efficiencies were achieved. However, the inlet of the UFBR was clogged several times due to the accumulation of biologically produced elemental sulfur particles and the clogging resulted in operational problems. When the UFBR was fed with the H2S absorbed from the biogas and operated with an influent pH of 8-9, around 98 % sulfide and 97 % nitrate removal efficiencies were obtained. In this way, above 95 % of the H2S in the biogas was removed as elemental sulfur and the reactor effluent was reused as scrubbing liquid without any clogging problem.

  2. Enzymes desulfurizing diesel fuel in pilot plant tests

    SciTech Connect

    Rhodes, A.K.

    1995-05-15

    Energy BioSystems Corp., The Woodlands, Texas, is collecting data from a new 5 b/d, continuous-operation, biocatalytic desulfurization (BDS) pilot plant. Hurdles to commercialization are catalyst activity, stability, and fermentation yield. Since 1990, however, Energy BioSystems Corp. (EBC) has made great strides in improving all three of these factors. The BDS process uses enzymes to remove organically bound sulfur from petroleum streams at mild temperatures and atmospheric pressure. Objectives of the pilot plant studies include: validating and refining the computer simulations used to control the process and establishing the process design basis. So far, the results from pilot plant operations have met expectations. The projected 45% desulfurization rate has been achieved, within a few percent. This rate was simply the target for the initial evaluation experiments, and that the process is capable of desulfurizing almost to extinction.

  3. Coal desulfurization by low temperature chlorinolysis, phase 3

    NASA Technical Reports Server (NTRS)

    Kalvinskas, J. J.; Rohatgi, N. K.; Ernest, J.

    1981-01-01

    Laboratory scale, bench scale batch reactor, and minipilot plant tests were conducted on 22 bituminous, subbituminous, and lignite coals. Chemical pretreatment and post treatment of coals relative to the chlorination were tried as a means of enhancing desulfurization by the chlorinolysis process. Elevated temperature (500-700 C) hydrogen treatment of chlorinolysis-processed coal at atmospheric pressure was found to substantially increase coal desulfurization up to 90 percent. Sulfur forms, proximate and ultimate analyses of the processed coal are included. Minipilot plant operation indicates that the continuous flow reactor provides coal desulfurization results comparable to those obtained in the batch reactor. Seven runs were conducted at coal feed rates of 1.5 to 8.8 kg per hour using water and methylchloroform solvents, gaseous chlorine feed of 3 to 31.4 SCFH at 21 to 70 C, and atmospheric pressure for retention times of 20 to 120 minutes.

  4. English Leadership Quarterly. 1991.

    ERIC Educational Resources Information Center

    Strickland, James, Ed.

    1991-01-01

    These four issues of the English Leadership Quarterly represent the quarterly for 1991. Articles in number 1 deal with whole language and include: "CEL: Shorter and Better" (Myles D. Eley); "Toward a New Philosophy of Language Learning" (Kathleen Strickland); "Whole Language: Implications for Secondary Classrooms" (Barbara King-Shaver); "Whole…

  5. CSSEDC Quarterly. 1990.

    ERIC Educational Resources Information Center

    Strickland, James, Ed.

    1990-01-01

    These four issues of the CSSEDC Quarterly (Conference for Secondary School English Department Chairpersons) represent the quarterly for 1990. Articles in number 1 deal with student teachers and include: "Student Teaching: Smoothing Out the Rough Spots" (Susan B. Argyle and Fred C. Feitler); "A Partnership for Urban Student Teaching" (Jerome T.…

  6. CSSEDC Quarterly. 1989.

    ERIC Educational Resources Information Center

    Strickland, James, Ed.

    1989-01-01

    These four issues of the CSSEDC Quarterly (Conference for Secondary School English Department Chairpersons) represent the quarterly for 1989. Articles in number 1 deal with professional development, and include: "Sharing Expertise within a Department" (Martha R. Dolly); "Empowerment Develops a Computer Writing Center" (Norman L. Frey); "Videotapes…

  7. Comparison of uranium removal from groundwater by sorbents

    SciTech Connect

    Sams, B.; Blount, J.

    1997-12-31

    Several sorbents have been tested for the capability of uranium removal from two very chemically different groundwaters. Sorbents evaluated in the study include granular activated carbon, peat moss, ion exchange resin (all commercially available) as well as innovative products not commercially available. Screening experiments on all of the sorbents identified the most promising sorbents, which have been carried forward for isotherm and column studies. For the most promising sorbents, studies showed that uranium could be removed to below analytical detection limits. The effect of competing ions is also discussed.

  8. Sorbent-Bed Crop-Drying System

    NASA Technical Reports Server (NTRS)

    Roberts, Barry C.

    1992-01-01

    Proposed aeration system helps reduce spoilage of stored grain or other crop stored in bulk. Air circulates through bin, sorbent bed, and heat exchanger. Outside air cools circulating air in heat exchanger. Sensors measure temperature and humidity, and adjust dampers to obtain requisite temperature and humidity. Suitable for grain bins and shipping barges.

  9. Carbon dioxide capture process with regenerable sorbents

    DOEpatents

    Pennline, Henry W.; Hoffman, James S.

    2002-05-14

    A process to remove carbon dioxide from a gas stream using a cross-flow, or a moving-bed reactor. In the reactor the gas contacts an active material that is an alkali-metal compound, such as an alkali-metal carbonate, alkali-metal oxide, or alkali-metal hydroxide; or in the alternative, an alkaline-earth metal compound, such as an alkaline-earth metal carbonate, alkaline-earth metal oxide, or alkaline-earth metal hydroxide. The active material can be used by itself or supported on a substrate of carbon, alumina, silica, titania or aluminosilicate. When the active material is an alkali-metal compound, the carbon-dioxide reacts with the metal compound to generate bicarbonate. When the active material is an alkaline-earth metal, the carbon dioxide reacts with the metal compound to generate carbonate. Spent sorbent containing the bicarbonate or carbonate is moved to a second reactor where it is heated or treated with a reducing agent such as, natural gas, methane, carbon monoxide hydrogen, or a synthesis gas comprising of a combination of carbon monoxide and hydrogen. The heat or reducing agent releases carbon dioxide gas and regenerates the active material for use as the sorbent material in the first reactor. New sorbent may be added to the regenerated sorbent prior to subsequent passes in the carbon dioxide removal reactor.

  10. Silver oxide sorbent for carbon dioxide

    NASA Technical Reports Server (NTRS)

    Colombo, G. V.

    1974-01-01

    Material can be regenerated at least 20 times by heating at 250 C. Sorbent is compatible with environment of high humidity; up to 20% by weight of carbon dioxide can be absorbed. Material is prepared from silver carbonate, potassium hydroxide or carbonate, and sodium silicate.

  11. METAL CAPTURE BY SORBENTS IN COMBUSTION PROCESSES

    EPA Science Inventory

    The article gives results of an investigation of the use of sorbents to control trace metal emissions from combustion processes and an exploration of the underlying mechanisms. mphasis was on mechanisms in which the metal vapor was reactively scavenged by simple commercial sorben...

  12. [Drinking water decontamination with isolative sorbent disinfectants].

    PubMed

    Krasnov, M S

    2004-01-01

    Drinking water can be decontaminated with the use of isolative sorbent disinfectants. Consideration of the effectiveness of water disinfectants and the sorptive power of porous materials against bacteria and viruses attested to the favour of iodine and silver-containing disinfectants and their compositions on porous aggressive carriers to be employed in extreme conditions such as on board crewed space vehicles.

  13. 4. Northeast corner of quarters (executive officer's quarters), looking onto ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Northeast corner of quarters (executive officer's quarters), looking onto Quarter R (commanding officer's quarters), looking southeast - Naval Air Station Chase Field, Texas State Highway 202, 4.8 miles east of intersection of Texas State Highway 202 & U.S. State Highway 181, Beeville, Bee County, TX

  14. Process for desulfurization of coal and ores

    SciTech Connect

    Starbuck, A.

    1980-07-22

    A process for desulfurizing ores containing sulfur comprises the steps of: (A) crushing ore containing sulfur to a particle consistency; (B) feeding the crushed ore to a heated continuous-flow processor; (C) introducing pre-heated sulfur dissolving solvent into said processor with the crushed ore; (D) concurrently mixing and force conveying the crushed ore and solvent by augering in the continuous flow processor at an elevated temperature in which sulfur is dissolvable and is dissolved in a heated sulfur-solvent solution with suspended particles and a remaining ore, the processor being oriented for about horizontal augering; (E) separating the sulfur-solvent solution with suspended particles from the remaining ore at an elevated temperature; (F) drying the separated, remaining ore by evaporating remaining solvent from the ore; (G) recovering solvent from the ore drying step by condensing the evaporated solvent; (H) concurrently crystallizing sulfur dissolved in the sulfur-solvent solution and force conveying the sulfur-solvent solution and crystallizing sulfur by augering a continuous flow chilled processor wherein the sulfur-solvent solution and crystallizing sulfur are conveyed together in a concurrent manner as a mixture in a continuous forward direction at controlled reduced temperatures as substantially the entire mixture progresses to a separate separating step, said crystallizing sulfur existing in part as a suspension and in part as a precipitate; (I) separating both crystallized suspension sulfur and crystallized precipitate sulfur from the solvent solution; (J) drying the separated crystallized sulfur by evaporating the solvent from the crystallized sulfur, wherein a fine crystal sulfur product is obtained; and (K) recovering solvent from the crystallized sulfur drying step by condensing the veaporated solvent.

  15. Confined zone dispersion flue gas desulfurization demonstration. Quarterly report No. 10, February 17--May 31, 1993

    SciTech Connect

    Not Available

    1993-11-15

    The CZD process involves injecting a finely atomized slurry of reactive lime into the flue gas duct work of a coal-fired utility boiler. The principle of the confined zone is to form a wet zone of slurry droplets in the middle of the duct walls. The lime slurry reacts with part of the SO{sub 2} in the gas, and the reaction products dry to form solid particles. A solids collector, typically an electrostatic precipitator (ESP) downstream from the point of injection, captures the reaction products along with the fly ash entrained in the flue gas. The demonstration is being conducted at Penelec`s Seward Station, Unit No. 15. This boiler is a 147 MWe coal-fired unit, which utilizes Pennsylvania bituminous coal (approximately 1.2 to 2.5% sulfur). One of the two flue gas ducts leading from the boiler has been retrofitted with the CZD technology. The first existing ESP installed in the station is immediately behind the air preheater. The second ESP, installed about 15 years ago, is about 80 feet away from the first ESP. The goal of this demonstration is to prove the technical and economic feasibility of the CZD technology on a commercial scale. The process is expected to achieve 50% SO{sub 2}

  16. Tidd PFBC demonstration project. Quarterly report, October--December 1993

    SciTech Connect

    Not Available

    1994-01-01

    This is the 27th Technical Progress Report submitted to the Department of Energy in connection with the Cooperative Agreement between the DOE and the Ohio Power Company for the Tidd PFBC Demonstration Plant. This report covers the period from October 1, 1993 to December 31, 1993. Major activities during this period involve: (1) The unit operated for 720 hours on coal. (2) There were five gas turbine starts, five bed preheater starts, and three operating periods on coal fire. (3) During the quarter, total gross generation was 36,672 MWH, the peak unit output for one hour was 64 MWH, and the coal consumption was 17,251 tons. (4) Six performance tests were run during this quarter. (5) The unit was tested with four sorbent feed points. (6) The gas turbine low pressure compressor was disassembled to repair cracks in the stationary guide vanes; and (7) a request was sent to the DOE requesting funding for an additional year of operation. Major items planned for the next period include: (a) Continuation of sorbent utilization tests at various bed levels and sulfur retention values and with different coals and adsorbents; and (b) operation at full load.

  17. Sorbent utilization studies using a mini-pilot spray dryer. Final report, 1 September 1992--31 August 1993

    SciTech Connect

    Keener, T.C.; Khang, S.J.; Wang, J.; Sanders, J.F.

    1993-09-30

    The main body of the report consists of four parts: 1. additives to change process chemistry for SO{sub 2} absorption by Ca(OH){sub 2} slurry; 2. recycle tests and hydration of fly ash with Ca(OH){sub 2} to increase reactivity; 3. limestone as an alternative sorbent and additive effects; 4. physical and chemical model developments for some of the additive effects and spray dryer mathematical model application. As the concentration of SO{sub 2} in the flue gases increases, the SO{sub 2} removal efficiency will go down. Additives such as delinquent salts (NaOH, NaCl, and NaHCO{sub 3}) have been shown to improve SO{sub 2} uptake, and these additive tests have indicated that SO{sub 2} uptake may be increased by as much as 60% over baseline conditions. Other additives such as H{sub 2}O{sub 2}, sugar, and some organic acids which can change the chemical reaction processes are suggested and tested, and some promising results have been obtained. Recycle has been shown to increase sorbent utilization by allowing partially reacted sorbent to react further with the SO{sub 2} in the flue gases. Two types of Ohio coal fly ashes have been extensively studied, and improvement of utilization in spray dryer flue gas desulfurization has been demonstrated. Limestone represents an area where significant cost savings can be realized. The spray dryer tests were designed to provide some results for understanding the magnitude of the limestone performance in the spray dryer system and the additive effects. The additive effects on increasing SO{sub 2} absorption by Ca(OH){sub 2} slurry were investigated, and the chemical and physical properties of these tested additives were studied. Some models have been formed to explain the additive phenomena.

  18. Workshop on sulfur chemistry in flue gas desulfurization

    SciTech Connect

    Wallace, W.E. Jr.

    1980-05-01

    The Flue Gas Desulfurization Workshop was held at Morgantown, West Virginia, June 7-8, 1979. The presentations dealt with the chemistry of sulfur and calcium compounds in scrubbers. DOE and EPRI programs in this area are described. Ten papers have been entered individually into EDB and ERA. (LTN)

  19. Selecting the right pumps and valves for flue gas desulfurization

    SciTech Connect

    Ellis, D.; Ahluwalia, H.

    2006-07-15

    Limestone slurry needs to move efficiently through a complex process, meaning that selecting the right pumps and valves is critical. The article discusses factors to consider in selecting pumps and values for flue gas desulfurization process in coal-fired power plants. 2 photos.

  20. FLUE GAS DESULFURIZATION: THE STATE OF THE ART

    EPA Science Inventory

    The paper gives results of a review of commercially available flue gas desulfurization (FGD) technologies that have an established record of full-scale performance. (NOTE: Sulfur dioxide (SO2) scrubbers may be used by coal-fired electrcity generating units to meet the requiremen...

  1. Pyrite surface characterization and control for advanced fine coal desulfurization technologies

    SciTech Connect

    Wang, X.H.; Leonard, J.W.; Parekh, B.K.; Jiang, C.L.

    1992-01-01

    This is the 9th quarterly technical progress report for the project entitled Pyrite surface characterization and control for advanced fine coal desulfurization technologies'', DE-FG22-90PC90295. The work presented in this report was performed from September 1, 1992 to November 31, 1992. The objective of the project is to conduct extensive fundamental studies on the surface chemistry of pyrite oxidation and flotation and to understand how the alteration of the coal-pyrite surface affects the efficiency of pyrite rejection in coal flotation. During this reporting period, the surface oxidation of pyrite in various electrolytes was investigated. It has been demonstrated, for the first time, that borate, a pH buffer and electrolyte used by many previous investigators in studying sulfide mineral oxidation, actively participates in the surface oxidation of pyrite. In borate solutions, the surface oxidation of pyrite is tronly enhanced. The anodic oxidation potential of pyrite is lowered by more than 0.4 volts. The initial reaction of the borate enhanced pyrite oxidation can be described by:FeS[sub 2] + B(OH)[sub 4][sup =] ------> [S[sub 2]Fe-B(OH)[sub 4

  2. Coal desulfurization in a rotary kiln combustor

    SciTech Connect

    Cobb, J.T. Jr.

    1990-08-15

    BCR National Laboratory (BCRNL) has initiated a project aimed at evaluating the technical and economic feasibility of using a rotary kiln, suitably modified, to burn Pennsylvania anthracite wastes, co-fired with high-sulfur bituminous coal. Limestone will be injected into the kiln for sulfur control, to determine whether high sulfur capture levels can be achieved with high sorbent utilization. The principal objectives of this work are: (1) to prove the feasibility of burning anthracite refuse, with co-firing of high-sulfur bituminous coal and with limestone injection for sulfur emissions control, in a rotary kiln fitted with a Universal Energy International (UEI) air injector system; (2) to determine the emissions levels of SO{sub x} and NO{sub x} and specifically to identify the Ca/S ratios that are required to meet New Source Performance Standards; (3) to evaluate the technical and economic merits of a commercial rotary kiln combustor in comparison to fluidized bed combustors; and, (4) to ascertain the need for further work, including additional combustion tests, prior to commercial application, and to recommend accordingly a detailed program towards this end.

  3. Utility flue gas mercury control via sorbent injection

    SciTech Connect

    Chang, R.; Carey, T.; Hargrove, B.

    1996-12-31

    The potential for power plant mercury control under Title III of the 1990 Clean Air Act Amendments generated significant interest in assessing whether cost effective technologies are available for removing the mercury present in fossil-fired power plant flue gas. One promising approach is the direct injection of mercury sorbents such as activated carbon into flue gas. This approach has been shown to be effective for mercury control from municipal waste incinerators. However, tests conducted to date on utility fossil-fired boilers show that it is much more difficult to remove the trace species of mercury present in flue gas. EPRI is conducting research in sorbent mercury control including bench-scale evaluation of mercury sorbent activity and capacity with simulated flue gas, pilot testing under actual flue gas conditions, evaluation of sorbent regeneration and recycle options, and the development of novel sorbents. A theoretical model that predicts maximum mercury removals achievable with sorbent injection under different operating conditions is also being developed. This paper presents initial bench-scale and model results. The results to date show that very fine and large amounts of sorbents are needed for mercury control unless long residence times are available for sorbent-mercury contact. Also, sorbent activity and capacity are highly dependent on flue gas composition, temperature, mercury species, and sorbent properties. 10 refs., 4 figs., 2 tabs.

  4. Land application uses for dry flue gas desulfurization by-products. Executive summary

    SciTech Connect

    Dick, W.; Bigham, J.; Forster, R.; Hitzhusen, F.; Lal, R.; Stehouwer, R.; Traina, S.; Wolfe, W.; Haefner, R.; Rowe, G.

    1999-01-31

    Flue gas desulfurization (FGD) scrubbing technologies create several types of by-products. This project focused primarily on by-product materials obtained from what are commonly called ''dry scrubbers'' which produce a dry, solid material consisting of excess sorbent, reaction product that contains sulfate and sulfite, and coal fly ash. Prior to this project, dry FGD by-products were generally treated as solid wastes and disposed in landfills. However, landfill sites are becoming scarce and tipping fees are constantly increasing; The major objective of this project was to develop beneficial uses, via recycling, capable of providing economic benefits to both the producer and the end user of the FGD by-product. It is equally important, however, that the environmental impacts be carefully assessed so that the new uses developed are not only technically feasible but socially acceptable. Specific objectives developed for this project were derived over an 18-month period during extensive discussions with personnel from industry, regulatory agencies and research institutions. These were stated as follows: Objective 1: To characterize the material generated by dry FGD processes. Objective 2: To demonstrate the utilization of dry FGD by-product as a soil amendment on agricultural lands and on abandoned and active surface coal mines in Ohio. Objective 3: To demonstrate the use of dry FGD by-product as an engineering material for soil stabilization. Objective 4: To determine the quantities of dry FGD by-product that can be utilized in each of these applications. Objective 5. To determine the environmental and economic impacts of utilizing the material. Objective 6. To calibrate environmental, engineering, and economic models that can be used to determine the applicability and costs of utilizing these processes at other sites.

  5. Production of manufactured aggregates from flue gas desulfurization by-products

    SciTech Connect

    Wu, M.M.; McCoy, D.C.; Fenger, M.L.; Scandrol, R.O.; Winschel, R.A.; Withum, J.A.; Statnick, R.M.

    1999-07-01

    CONSOL R and D has developed a disk pelletization process to produce manufactured aggregates from the by-products of various technologies designed to reduce sulfur emissions produced from coal utilization. Aggregates have been produced from the by-products of the Coolside and LIMB sorbent injection, the fluidized-bed combustion (FBC), spray dryer absorption (SDA), and lime and limestone wet flue gas desulfurization (FGD) processes. The aggregates produced meet the general specifications for use as road aggregate in road construction and for use as lightweight aggregate in concrete masonry units. Small field demonstrations with 1200 lb to 5000 lb of manufactured aggregates were conducted using aggregates produced from FBC ash and lime wet FGD sludge in road construction and using aggregates made from SDA ash and lime wet FGD sludge to manufacture concrete blocks. The aggregates for this work were produced with a bench-scale (200--400 lb batch) unit. In 1999, CONSOL R and D constructed and operated a 500 lb/hr integrated, continuous pilot plant. A variety of aggregate products were produced from lime wet FGD sludge. The pilot plant test successfully demonstrated the continuous, integrated operation of the process. The pilot plant demonstration was a major step toward commercialization of manufactured aggregate production from FGD by-products. In this paper, progress made in the production of aggregates from dry FGD (Coolside, LIMB, SDA) and FBC by-products, and lime wet FGD sludge is discussed. The discussion covers bench-scale and pilot plant aggregate production and aggregate field demonstrations.

  6. Desulfurization ability of refining slag with medium basicity

    NASA Astrophysics Data System (ADS)

    Yu, Hui-xiang; Wang, Xin-hua; Wang, Mao; Wang, Wan-jun

    2014-12-01

    The desulfurization ability of refining slag with relative lower basicity ( B) and Al2O3 content ( B = 3.5-5.0; 20wt%-25wt% Al2O3) was studied. Firstly, the component activities and sulfide capacity ( C S) of the slag were calculated. Then slag-metal equilibrium experiments were carried out to measure the equilibrium sulfur distribution ( L S). Based on the laboratorial experiments, slag composition was optimized for a better desulfurization ability, which was verified by industrial trials in a steel plant. The obtained results indicated that an MgO-saturated CaO-Al2O3-SiO2-MgO system with the basicity of about 3.5-5.0 and the Al2O3 content in the range of 20wt%-25wt% has high activity of CaO ( a CaO), with no deterioration of C S compared with conventional desulfurization slag. The measured L S between high-strength low-alloyed (HSLA) steel and slag with a basicity of about 3.5 and an Al2O3 content of about 20wt% and between HSLA steel and slag with a basicity of about 5.0 and an Al2O3 content of about 25wt% is 350 and 275, respectively. The new slag with a basicity of about 3.5-5.0 and an Al2O3 content of about 20wt% has strong desulfurization ability. In particular, the key for high-efficiency desulfurization is to keep oxygen potential in the reaction system as low as possible, which was also verified by industrial trials.

  7. DEEP DESULFURIZATION OF DIESEL FUELS BY A NOVEL INTEGRATED APPROACH

    SciTech Connect

    Xiaoliang Ma; Michael Sprague; Lu Sun; Chunshan Song

    2002-10-01

    In order to reduce the sulfur level in liquid hydrocarbon fuels for environmental protection and fuel cell applications, deep desulfurization of a model diesel fuel and a real diesel fuel was conducted by our SARS (selective adsorption for removing sulfur) process using the adsorbent A-2. Effect of temperature on the desulfurization process was examined. Adsorption desulfurization at ambient temperature, 24 h{sup -1} of LHSV over A-2 is efficient to remove dibenzothiophene (DBT) in the model diesel fuel, but difficult to remove 4-methyldibenzothiophene (4-MDBT) and 4,6-dimethyl-dibenzothiophene (4,6-DMDBT). Adsorption desulfurization at 150 C over A-2 can efficiently remove DBT, 4-MDBT and 4,6-DMDBT in the model diesel fuel. The sulfur content in the model diesel fuel can be reduced to less than 1 ppmw at 150 C without using hydrogen gas. The adsorption capacity corresponding to the break-through point is 6.9 milligram of sulfur per gram of A-2 (mg-S/g-A-2), and the saturate capacity is 13.7 mg-S/g-A-2. Adsorption desulfurization of a commercial diesel fuel with a total sulfur level of 47 ppmw was also performed at ambient temperature and 24 h{sup -1} of LHSV over the adsorbent A-2. The results show that only part of the sulfur compounds existing in the low sulfur diesel can be removed by adsorption over A-2 at such operating conditions, because (1) the all sulfur compounds in the low sulfur diesel are the refractory sulfur compounds that have one or two alkyl groups at the 4- and/or 6-positions of DBT, which inhibit the approach of the sulfur atom to the adsorption site; (2) some compounds coexisting in the commercial low sulfur diesel probably inhibit the interaction between the sulfur compounds and the adsorbent. Further work in determining the optimum operating conditions and screening better adsorbent is desired.

  8. Layered solid sorbents for carbon dioxide capture

    SciTech Connect

    Li, Bingyun; Jiang, Bingbing; Gray, McMahan L; Fauth, Daniel J; Pennline, Henry W; Richards, George A

    2014-11-18

    A solid sorbent for the capture and the transport of carbon dioxide gas is provided having at least one first layer of a positively charged material that is polyethylenimine or poly(allylamine hydrochloride), that captures at least a portion of the gas, and at least one second layer of a negatively charged material that is polystyrenesulfonate or poly(acryclic acid), that transports the gas, wherein the second layer of material is in juxtaposition to, attached to, or crosslinked with the first layer for forming at least one bilayer, and a solid substrate support having a porous surface, wherein one or more of the bilayers is/are deposited on the surface of and/or within the solid substrate. A method of preparing and using the solid sorbent is provided.

  9. Molecular biological enhancement of coal desulfurization

    SciTech Connect

    Litchfield, J.H.; Fry, I.; Wyza, R.E.; Palmer, D.T.; Zupancic, T.J.; Conkle, H.N. ); Delgado, O.; Tuovinen, O.H. )

    1990-09-14

    The objective of this project is to produce one or more microorganisms capable of removing the organic and inorganic sulfur in coal. The specific technical objectives of the project are to: clone and characterize the genes encoding the enzymes of the 4S'' pathway (sulfoxide/sulfone/sulfonate/sulfate) for release of organic sulfur from coal; return multiple copies of genes to the original host to enhance the biodesulfurization activity of that organism; transfer this pathway into a fast-growing chemolithotrophic bacterium; and conduct a batch-mode optimization/analysis of scale-up variables. This report presents the results of research at Battelle during the 5th Quarterly Report period beginning on June 15, 1990. 1 ref., 6 figs., 4 tabs.

  10. Development of Novel Carbon Sorbents for CO{sub 2} Capture

    SciTech Connect

    Krishnan, Gopala; Hornbostel, Marc; Bao, Jianer; Perez, Jordi; Nagar, Anoop; Sanjurjo, Angel

    2013-11-30

    -fired boil at the University of Toledo campus for about 135 h, comprising 7,000 cycles of adsorption and desorption using the desulfurized flue gas that contained only 4.5% v/v CO{sub 2}. A capture efficiency of 85 to 95% CO{sub 2} was achieved under steady-state conditi ons. The CO{sub 2} adsorption capacity did not change significantly during the field test, as determined from the CO{sub 2} adsorptio isotherms of fresh and used sorbents. The process is also being tested using the flue gas from a PC-fired power plant at the National Carbon Capture Center (NCCC), Wilsonville, AL. The cost of electricity was calculated for CO{sub 2} capture using the carbon sorbent and compared with the no-CO{sub 2} capture and CO{sub 2} capture with an amine-based system. The increase i the levelized cost of electricity (L-COE) is about 37% for CO{sub 2} capture using the carbon sorbent in comparison to 80% for an amine-based system, demonstrating the economic advantage of C capture using the carbon sorbent. The 37% increase in the L-COE corresponds to a cost of capture of $30/ton of CO{sub 2}, including compression costs, capital cost for the capture system, and increased plant operating and capital costs to make up for reduced plant efficiency. Preliminary sensitivity analyses showed capital costs, pressure drops in the adsorber, and steam requirement for the regenerator are the major variables in determining the cost of CO{sub 2} capture. The results indicate that further long-term testing with a flue gas from a pulverized coal­ fired boiler should be performed to obtain additional data relating to the effects of flue gas contaminants, the ability to reduce pressure drop by using alternate structural packing , and the use of low-cost construction materials.

  11. Adsorption of Ammonia on Regenerable Carbon Sorbents

    NASA Technical Reports Server (NTRS)

    Wójtowicz, Marek A.; Cosgrove, Jesph E.; Serio, Michael A..; Wilburn, Monique

    2015-01-01

    Results are presented on the development of reversible sorbents for the combined carbon dioxide, moisture, and trace-contaminant (TC) removal for use in Extravehicular Activities (EVAs), and more specifically in the Primary Life Support System (PLSS). The currently available life support systems use separate units for carbon dioxide, trace contaminants, and moisture control, and the long-term objective is to replace the above three modules with a single one. Data on sorption and desorption of ammonia, which is a major TC of concern, are presented in this paper. The current TC-control technology involves the use of a packed bed of acid-impregnated granular charcoal, which is non-regenerable, and the carbon-based sorbent under development in this project can be regenerated by exposure to vacuum at room temperature. In this study, several carbon sorbents were fabricated and tested for ammonia sorption. Ammonia-sorption capacity was related to carbon pore structure characteristics, and the temperature of oxidative carbon-surface treatment was optimized for enhanced ammonia-sorption performance.

  12. Supported-sorbent injection. Final report

    SciTech Connect

    Nelson, S. Jr.

    1997-07-01

    A new retrofitable, wastefree acid-rain control concept was pilot-tested at Ohio Edison`s high-sulfur coal-fired R.E. Burger generating station at the 2-MWe level. During the project, moistened {open_quotes}supported{close_quotes} sorbents, made from a combination of lime and vermiculite or perlite, were injected into a humidified 6,500-acfm flue-gas slipstream. After the sorbents reacted with the sulfur dioxide in the flue gas, they were removed from ductwork with a cyclone and baghouse. The $1.0 million project was co-funded by Sorbent Technologies Corporation, the Ohio Edison Company, and the Ohio Coal Development Office. The project included a preliminary bench-scale testing phase, construction of the pilot plant, parametric studies, numerous series of recycle tests, and a long-term run. The project proceeded as anticipated and achieved its expected results. This duct injection technology successfully demonstrated SO{sub 2}-removal rates of 80 to 90% using reasonable stoichiometric injection ratios (2:1 Ca:S) and approach temperatures (20-25F). Under similar conditions, dry injection of hydrated lime alone typically only achieves 40 to 50% SO{sub 2} removal. During the testing, no difficulties were encountered with deposits in the ductwork or with particulate control, which have been problems in tests of other duct-injection schemes.

  13. Oil removal from used sorbents using a biosurfactant.

    PubMed

    Wei, Q F; Mather, R R; Fotheringham, A F

    2005-02-01

    Oil spills impose serious damage on the environment. Mechanical recovery by the help of oil sorbents is one of the most important countermeasures in oil spill response. Most sorbents, however, end up in landfills or in incineration after a single use. These options either produce another source of pollution or increase the oil recovery cost. In this study a biosurfactant was used to clean used oil sorbents. This use of biosurfactants is new. Washing parameters tested included sorbent type, washing time, surfactant dosage and temperature. It was found that with biosurfactant washing more than 95% removal of the oil from sorbents was achieved, depending on the washing conditions. Biosurfactants were found to have considerable potential for recycling the used sorbents.

  14. A novel sorbent for transport reactors and fluidized bed reactors

    SciTech Connect

    Copeland, R.; Cesario, M.; Gershanovich, Y.; Sibold, J.; Windecker, B.

    1998-12-31

    Coal Fired Gasifier Combined Cycles (GCC) have both high efficiency and very low emissions. GCCs critically need a method of removing the H{sub 2}S produced from the sulfur in the coal from the hot gases. There has been extensive research on hot gas cleanup systems, focused on the use of a zinc oxide based sorbent (e.g., zinc titanate). TDA Research, Inc. (TDA) is developing a novel sorbent with improved attrition resistance for transport reactors and fluidized bed reactors. The authors are testing sorbents at conditions simulating the operating conditions of the Pinon Pine clean coal technology plant. TDA sulfided several different formulations at 538 C and found several that have high sulfur capacity when tested in a fluidized bed reactor. TDA initiated sorbent regeneration at 538 C. The sorbents retained chemical activity with multiple cycles. Additional tests will be conducted to evaluate the best sorbent formulation.

  15. Oxidative desulfurization of fuel oil by pyridinium-based ionic liquids.

    PubMed

    Zhao, Dishun; Wang, Yanan; Duan, Erhong

    2009-01-01

    In this work, an N-butyl-pyridinium-based ionic liquid [BPy]BF(4) was prepared. The effect of extraction desulfurization on model oil with thiophene and dibenzothiophene (DBT) was investigated. Ionic liquids and hydrogen peroxide (30%) were tested in extraction-oxidation desulfurization of model oil. The results show that the ionic liquid [BPy]BF(4) has a better desulfurization effect. The best technological conditions are: V(IL)/V(Oil) /V(H(2)O(2)) = 1:1:0.4, temperature 55 degrees C, the time 30 min. The ratio of desulfurization to thiophene and DBT reached 78.5% and 84.3% respectively, which is much higher than extraction desulfurization with simple ionic liquids. Under these conditions, the effect of desulfurization on gasoline was also investigated. The used ionic liquids can be recycled up to four times after regeneration. PMID:19924069

  16. Sorbent suspensions vs. sorbent columns for extracorporeal detoxification in hepatic failure.

    PubMed

    Ash, Stephen R; Sullivan, Thomas A; Carr, David J

    2006-04-01

    Hepatic failure is a significant medical problem which has been unsuccessfully treated by hemodialysis. However, similar therapies using recirculated dialysate regenerated by sorbents in place of single-pass dialysate have been beneficial in treating acute-on-chronic liver failure. The advantages of sorbent-based treatments include some selectivity of toxin removal and improved removal of protein-bound toxins. Activated carbon has been extensively used in detoxification systems, but has often had insufficient toxin capacity. Powdered activated carbon, because of its large surface area, can provide greater binding capacity for bilirubin and other toxins than granular carbon commonly used in detoxifying columns. Methods of using powdered carbon in extracorporeal blood treatment devices are reviewed in the present paper, including liver dialysis and a new sorbent suspension reactor (SSR); and the abilities and limitations of the SSR and columns to process protein solutions are discussed. PMID:16684216

  17. Regenerable sorbent technique for capturing CO.sub.2 using immobilized amine sorbents

    DOEpatents

    Pennline, Henry W; Hoffman, James S; Gray, McMahan L; Fauth, Daniel J; Resnik, Kevin P

    2013-08-06

    The disclosure provides a CO.sub.2 absorption method using an amine-based solid sorbent for the removal of carbon dioxide from a gas stream. The method disclosed mitigates the impact of water loading on regeneration by utilizing a conditioner following the steam regeneration process, providing for a water loading on the amine-based solid sorbent following CO.sub.2 absorption substantially equivalent to the moisture loading of the regeneration process. This assists in optimizing the CO.sub.2 removal capacity of the amine-based solid sorbent for a given absorption and regeneration reactor size. Management of the water loading in this manner allows regeneration reactor operation with significant mitigation of energy losses incurred by the necessary desorption of adsorbed water.

  18. DEEP DESULFURIZATION OF DIESEL FUELS BY A NOVEL INTEGRATED APPROACH

    SciTech Connect

    Xiaoliang Ma; Uday Turaga; Shingo Watanabe; Subramani Velu; Chunshan Song

    2004-05-01

    The overall objective of this project is to explore a new desulfurization system concept, which consists of efficient separation of the refractory sulfur compounds from diesel fuel by selective adsorption, and effective hydrodesulfurization of the concentrated fraction of the refractory sulfur compounds in diesel fuels. Our approaches focused on (1) selecting and developing new adsorbents for selective adsorption of sulfur or sulfur compounds in commercial diesel fuel; (2) conducting the adsorption desulfurization of model fuels and real diesel fuels by the selective-adsorption-for-removing-sulfur (PSUSARS) process over various developed adsorbents, and examining the adsorptive desulfurization performance of various adsorbents; (3) developing and evaluating the regeneration methods for various spent adsorbent; (4) developing new catalysts for hydrodesulfurization of the refractory sulfur existing in the commercial diesel fuel; (5) on the basis of the fundamental understanding of the adsorptive performance and regeneration natures of the adsorbents, further confirming and improving the conceptual design of the novel PSU-SARS process for deep desulfurization of diesel fuel Three types of adsorbents, the metal-chloride-based adsorbents, the activated nickel-based adsorbents and the metal-sulfide-based adsorbents, have been developed for selective adsorption desulfurization of liquid hydrocarbons. All of three types of the adsorbents exhibit the significant selectivity for sulfur compounds, including alkyl dibenzothiophenes (DBTs), in diesel fuel. Adsorption desulfurization of real diesel fuels (regular diesel fuel (DF), S: 325 ppmw; low sulfur diesel fuel (LSD-I), S: 47 ppmw) over the nickel-based adsorbents (A-2 and A-5) has been conducted at different conditions by using a flowing system. The adsorption capacity of DF over A-2 corresponding to an outlet sulfur level of 30 ppmw is 2.8 mg-S/g-A. The adsorption capacity of LSD-I over A-5 corresponding to the break

  19. Summary and assessment of METC zinc ferrite hot coal gas desulfurization test program, final report: Volume 1

    SciTech Connect

    Underkoffler, V.S.

    1986-12-01

    The Morgantown Energy Technology Center (METC) has conducted a test program to develop a zinc ferrite-based high temperature desulfurization process which could be applied to fuel gas entering downstream components such as molten carbonate fuel cells or gas turbines. As a result of prior METC work with iron oxide and zinc oxide sorbents, zinc ferrite evolved as a candidate with the potential for high capacity, low equilibrium levels of H/sub 2/S, and structural stability after multiple regenerations. The program consisted of laboratory-scale testing with a two-inch diameter reactor and simulated fixed-bed gasifier gas; bench-scale testing with a six-inch diameter reactor and actual gas from the METC 42-inch fixed bed gasifier; as well as laboratory-scale testing of zinc ferrite with simulated fluidized bed gasifier gas. Optimum operating parameters for zinc ferrite such as temperatures, gas compositions, and space velocities are discussed. From the test results, salient features of zinc ferrite were derived and discussed in regard to system implications, issues raised, and technical requirements. 47 refs., 53 figs., 41 tabs.

  20. EMSL Quarterly Highlights Report: 1st Quarter, FY08

    SciTech Connect

    Showalter, Mary Ann

    2008-01-28

    The EMSL Quarterly Highlights Report covers the science, staff and user recognition, and publication activities that occurred during the 1st quarter (October 2007 - December 2007) of Fiscal Year 2008.

  1. EMSL Quarterly Highlights Report: FY 2008, 3rd Quarter

    SciTech Connect

    Showalter, Mary Ann

    2008-09-16

    The EMSL Quarterly Highlights Report covers the science, staff and user recognition, and publication activities that occurred during the 1st quarter (October 2007 - December 2007) of Fiscal Year 2008.

  2. EMSL Quarterly Highlights Report: 1st Quarter, Fiscal Year 2009

    SciTech Connect

    Showalter, Mary Ann; Kathmann, Loel E.; Manke, Kristin L.

    2009-02-02

    The EMSL Quarterly Highlights Report covers the science, staff and user recognition, and publication activities that occurred during the 1st quarter (October 2008 - December 2008) of Fiscal Year 2009.

  3. Short-term energy outlook. Quarterly projections, second quarter 1996

    SciTech Connect

    1996-04-01

    The Energy Information Administration prepares quarterly, short-term energy supply, demand, and price projections. The forecasts in this issue cover the second quarter of 1996 through the fourth quarter of 1997. Changes to macroeconomic measures by the Bureau of Economic Analysis have been incorporated into the STIFS model used.

  4. Natural desulfurization in coal-fired units using Greek lignite.

    PubMed

    Konidaris, Dimitrios N

    2010-10-01

    This paper analyzes the natural desulfurization process taking place in coal-fired units using Greek lignite. The dry scrubbing capability of Greek lignite appears to be extremely high under special conditions, which can make it possible for the units to operate within the legislative limits of sulfur dioxide (SO2) emissions. According to this study on several lignite-fired power stations in northern Greece, it was found that sulfur oxide emissions depend on coal rank, sulfur content, and calorific value. On the other hand, SO2 emission is inversely proportional to the parameter gammaCO2(max), which is equal to the maximum carbon dioxide (CO2) content by volume of dry flue gas under stoichiometric combustion. The desulfurization efficiency is positively correlated to the molar ratio of decomposed calcium carbonate to sulfur and negatively correlated to the free calcium oxide content of fly ash. PMID:21090555

  5. Introduction to limestone flue gas desulfurization: Videotape workbook

    SciTech Connect

    Not Available

    1988-01-01

    The workbook is designed to accompany the Electric Power Research Institute's (EPRI's) videotape, ''Introduction to Limestone Flue Gas Desulfurization.'' To complement the videotape, the workbook provides additional information on limestone flue gas desulfurization (FGD) and a guide to sources of still more information. The videotape itself presents an introduction to the chemistry involved in a limestone FGD system. Following a description of a typical system, the basic chemical reactions that occur in this process are detailed. The most common operation problems in limestone FGD---low sulfur dioxide removal, low limestone utilization, and scaling---are reviewed with regard to how process chemistry can be controlled to alleviate these problems. This tape is an introduction only; future tapes will cover limestone FGD performance indicators and troubleshooting in more detail.

  6. Natural desulfurization in coal-fired units using Greek lignite.

    PubMed

    Konidaris, Dimitrios N

    2010-10-01

    This paper analyzes the natural desulfurization process taking place in coal-fired units using Greek lignite. The dry scrubbing capability of Greek lignite appears to be extremely high under special conditions, which can make it possible for the units to operate within the legislative limits of sulfur dioxide (SO2) emissions. According to this study on several lignite-fired power stations in northern Greece, it was found that sulfur oxide emissions depend on coal rank, sulfur content, and calorific value. On the other hand, SO2 emission is inversely proportional to the parameter gammaCO2(max), which is equal to the maximum carbon dioxide (CO2) content by volume of dry flue gas under stoichiometric combustion. The desulfurization efficiency is positively correlated to the molar ratio of decomposed calcium carbonate to sulfur and negatively correlated to the free calcium oxide content of fly ash.

  7. Coal desulfurization in a rotary kiln combustor

    SciTech Connect

    Cobb, J.T. Jr.

    1991-04-22

    The focus of our work during the first quarter of 1991 was on combustion tests at the PEDCO rotary kiln reactor at North American Rayon (NARCO) plant in Elizabethton, TN. The tests had essentially tow related objectives: (a) to obtain basic data on the combustion of anthracite culm in a rotary kiln reactor, and (b) upon the test results, determine how best to proceed with our own planned program at the Humphrey Charcoal kiln in Brookville, PA. The rationale for the tests at PEDCO arose from process analysis which posted red flags on the feasibility of burning low-grade, hard-to-burn fuels like anthracite culms, in the rotary kiln. The PEDCO unit afforded a unique opportunity to obtain some quick answers at low cost. Two different anthracite culm fuels were tested: a so-called Jeddo culm with an average heating value of 7000 Btu/lb, and a relatively poorer culm, and Emerald'' culm, with an average heating value of 5000 Btu/lb. An attempt was also made to burn a blend of the Emerald culm with bituminous coal in 75/25 percent proportions. This report describes the tests, their chronology, and preliminary results. As it turned out, the PEDCO unit is not configured properly for the combustion of anthracite culm. As a result, it proved difficult to achieve a sustained period of steady-state combustion operation, and combustion efficiencies were low even when supplemental fuel was used to aid combustion of the culm. 1 fig., 2 tabs.

  8. Confined zone dispersion flue gas desulfurization demonstration

    SciTech Connect

    Not Available

    1993-01-15

    This is the sixth quarterly report for this project and it covers work performed on Phase 3a of the project from February 1, 1992 through April 30, 1992. Extension of the parametric test period through June 1992 provides an opportunity to regain most of the schedule slippage, but only if the modifications needed for continuous operation of the CZD system are installed concurrent with the extended test period. These modifications include automation of the lime preparation and transfer system, automatic injection control, and related instrumentation and controls as necessary to integrate the operation of the CZD system with Seward Station Boiler No. 15. Early installation of these modifications would permit testing, debugging and adjustment of the automatic control system during the parametric test period. Results of current testing indicate that considerable testing and adjustment will be required to optimize operation of the CZD system after it is automated for continuous operation. Therefore, we intend to incorporate in Phase 3a(parametric testing) the system modifications needed for continuous automatic operation that were originally included in Phase 3b. Phase 3b would then be limited only to the one-year continuous demonstration.

  9. Molten iron oxysulfide as a superior sulfur sorbent. Technical progress report, December 1, 1991--February 29, 1992

    SciTech Connect

    Hepworth, M.T.

    1992-02-28

    Slagging combustors with injected lime or limestone are being considered as replacements for conventional coal burners. They have advantages in that they can be staged to reduce NO{sub x} and SO{sub x} emissions. Iron oxide, as an alternative to lime or limestone may be effective not only as a desulfurizing agent, but under the right conditions of oxygen potential and after combination with sulfur, the reaction products of coal gases with iron oxide can act as a flux to produce a fluid phase. The thermodynamic conditions for optimum removal of sulfur from the first stage of a coal combustor are being determined by experiment and by use of existing data. Analysis of the phase equilibria indicates that optimum conditions for deployment of the reducing stage of a multi-stage, burner operating with iron injection are close to the boundary of the liquid iron oxysulfide phase with iron-saturation. Two prior investigations differ with respect to the location of this phase boundary at temperatures over 1400{degree}C: with reference 1, showing the phase boundary nearer the iron-rich corner than reference 2 which gives the boundary further into the liquid region. In this quarter experimental studies were conducted on equilibrium compositions which are the most effective in achieving desulfurization. These conditions were studied by thermogravimetric analysis (TGA). They serve to check the data reported by the two above-reference investigations for their experimental conditions of 1200{degree}C, and also to check extend the data given in the literature to a temperature of 1300{degree}C. The model used for this interpolation was reported upon in the prior quarterly report (9/1/91-11/30/92 Appendix A).

  10. Exploring the Mechanism of Biocatalyst Inhibition in Microbial Desulfurization

    PubMed Central

    Abin-Fuentes, Andres; Mohamed, Magdy El-Said; Wang, Daniel I. C.

    2013-01-01

    Microbial desulfurization, or biodesulfurization (BDS), of fuels is a promising technology because it can desulfurize compounds that are recalcitrant to the current standard technology in the oil industry. One of the obstacles to the commercialization of BDS is the reduction in biocatalyst activity concomitant with the accumulation of the end product, 2-hydroxybiphenyl (HBP), during the process. BDS experiments were performed by incubating Rhodococcus erythropolis IGTS8 resting-cell suspensions with hexadecane at 0.50 (vol/vol) containing 10 mM dibenzothiophene. The resin Dowex Optipore SD-2 was added to the BDS experiments at resin concentrations of 0, 10, or 50 g resin/liter total volume. The HBP concentration within the cytoplasm was estimated to decrease from 1,100 to 260 μM with increasing resin concentration. Despite this finding, productivity did not increase with the resin concentration. This led us to focus on the susceptibility of the desulfurization enzymes toward HBP. Dose-response experiments were performed to identify major inhibitory interactions in the most common BDS pathway, the 4S pathway. HBP was responsible for three of the four major inhibitory interactions identified. The concentrations of HBP that led to a 50% reduction in the enzymes' activities (IC50s) for DszA, DszB, and DszC were measured to be 60 ± 5 μM, 110 ± 10 μM, and 50 ± 5 μM, respectively. The fact that the IC50s for HBP are all significantly lower than the cytoplasmic HBP concentration suggests that the inhibition of the desulfurization enzymes by HBP is responsible for the observed reduction in biocatalyst activity concomitant with HBP generation. PMID:24096431

  11. Coal desulfurization. (Latest citations from the Compendex database). Published Search

    SciTech Connect

    Not Available

    1993-06-01

    The bibliography contains citations concerning physical, chemical, and microbiological methods used in the removal of sulfur from coal. Oxydesulfurization, washing, electrochemical separation, oxidation, molten salts, microwave radiation, biodegradation, supercritical extraction, magnetic techniques, chlorinolysis, and flotation are among the processes considered. Sulfur pollution standards, environmental regulations and considerations, and process analyses and evaluations are discussed. Desulfurization of coal derived liquids and coal liquefaction are examined in separate bibliographies. (Contains 250 citations and includes a subject term index and title list.)

  12. A NOVEL APPROACH TO CATALYTIC DESULFURIZATION OF COAL

    SciTech Connect

    John G. Verkade

    1998-02-28

    The reactions of dialkyl mono- and disulfides and functionalized alkylthio compounds with sodium in refluxing hydrocarbon solvent (tetradecane, mesitylene or toluene) resulted in sulfur-free products in very high yields. Greater than 95% sulfur removal was observed when dialkyl mono or polysulfides were treated with Na in liquid ammonia. Polycyclic aromatic sulfur heterocycles were only moderately desulfurized under these conditions while phenylthio derivatives gave thiophenol as the major product and dithiophenols as the minor products.

  13. Molecular biological enhancement of coal desulfurization. Final report

    SciTech Connect

    Krawiec, S.

    1994-12-31

    During the period from 1986 through 1993 the prospect of bacterial desulfurization of fossil fuel was transformed from a theoretically appealing concept to a demonstrable laboratory phenomenon. Results from several laboratories confirmed that there was not one but, rather, several metabolic bases of selectively removing sulfur from the carbon frame of sulfur-containing organic compounds characteristic of fossil fuels. Results in this report relate solely to the so-called ``4S`` pathway (named for the four sulfur-containing compounds in the sequence: (l) dibenzothiophene [DBT] {yields} (2) dibenzothiophene sulfoxide [DBTO] {yields} (3) dibenzosulfone [DBTO{sup 2}] {yields} (4) dibenzosulfonate {yields} monohydroxybiphenyl [OH-BP] + SO{sub 4}{sup =}. [An additional desulfurized product, biphenyl, has been hypothesized and another, o,o{prime}-biphenyl, observed.]) The following subjects are discussed: isolating bacteria with a DbtS{sup +} phenotype; confirming the production of a desulfurized product; determining the identity of the isolates; determining the growth characteristics of the isolates in batch and continuous cultures; determining the kinetics and yields of product in batch and continuous cultures.

  14. Quarterly environmental data summary for first quarter 1999

    SciTech Connect

    1999-06-01

    In support of the Weldon Spring Site Remedial Action Project Federal Facilities Agreement, a copy of the Quarterly Environmental Data Summary (QEDS) for the first quarter of 1999 is enclosed. The data presented in this constitute the QEDS. The data, except for air monitoring data and site KPA generated data (uranium analyses), were received from the contract laboratories, verified by the Weldon Spring Site verification group and merged into the database during the first quarter of 1999. KPA results for on-site total uranium analyses performed during first quarter 1999 are included. Air monitoring data presented are the most recent complete sets of quarterly data.

  15. Anionic sorbents for arsenic and technetium species.

    SciTech Connect

    Lucero, Daniel A.; Moore, Robert Charles; Bontchev, Ranko Panayotov; Hasan, Ahmed Ali Mohamed; Zhao, Hongting; Salas, Fred Manuel; Holt, Kathleen Caroline

    2003-09-01

    Two sorbents, zirconium coated zeolite and magnesium hydroxide, were tested for their effectiveness in removing arsenic from Albuquerque municipal water. Results for the zirconium coated zeolite indicate that phosphate present in the water interfered with the sorption of arsenic. Additionally, there was a large quantity of iron and copper present in the water, corrosion products from the piping system, which may have interfered with the uptake of arsenic by the sorbent. Magnesium hydroxide has also been proven to be a strong sorbent for arsenic as well as other metals. Carbonate, present in water, has been shown to interfere with the sorption of arsenic by reacting with the magnesium hydroxide to form magnesium carbonate. The reaction mechanism was investigated by FT-IR and shows that hydrogen bonding between an oxygen on the arsenic species and a hydrogen on the Mg(OH)2 is most likely the mechanism of sorption. This was also confirmed by RAMAN spectroscopy and XRD. Technetium exists in multiple oxidation states (IV and VII) and is easily oxidized from the relatively insoluble Tc(IV) form to the highly water soluble and mobile Tc(VII) form. The two oxidation states exhibit different sorption characteristics. Tc(VII) does not sorb to most materials whereas Tc(IV) will strongly sorb to many materials. Therefore, it was determined that it is necessary to first reduce the Tc (using SnCl2) before sorption to stabilize Tc in the environment. Additionally, the effect of carbonate and phosphate on the sorption of technetium by hydroxyapatite was studied and indicated that both have a significant effect on reducing Tc sorption.

  16. New high-capacity, calcium-based sorbents, calcium silicate sorbents. Final report, 1993--August 31, 1994

    SciTech Connect

    Kenney, M.C.; Chiang, R.K.; Fillgrove, K.L.

    1995-02-01

    A search is being carried out for new calcium-based S0{sub 2} sorbents for induct injection. More specifically, a search is being carried out for induct injection calcium silicate sorbents that are highly cost effective. The objectives for the current year include the study of sorbents made from Ca(OH){sub 2}, from mixtures of Ca(OH){sub 2} and SiO{sub 2}, and from portland cement. They also include the study of sorbents made from model compounds. During this year, sorbents prepared from Ca(OH){sub 2} and from mixtures of Ca(OH){sub 2} and fumed SiO{sub 2} were investigated. The results show that very good SiO{sub 2}-modified Ca(OH){sub 2} sorbents in which the Si-to-Ca reactant ratio is low can be prepared from Ca(OH){sub 2} and fumed SiO{sub 2}. Sorbents prepared from Ca(OH){sub 2} and natural SiO{sub 2} or natural SiO{sub 2} sources were also studied. The results obtained show that very good SiO{sub 2}-modified Ca(OH){sub 2} sorbents and calcium silicate hydrate sorbents, C-S-H sorbents, can be prepared from Ca(OH){sub 2} and diatomite, pumice or perlite, minerals that are readily available. In addition. sorbents prepared from Ca{sub 3}SiO{sub 5} and {beta}-Ca{sub 2}SiO{sub 4} and from mixtures of these compounds and SiO{sub 2} were studied. The results secured demonstrate that very good C-S-H rich sorbents can be prepared from these compounds and from mixtures of them with SiO{sub 2}. They also provide information useful for interpreting the cement sorbent results. Sorbents prepared from cement and from mixtures of cement and natural SiO{sub 2} or SiO{sub 2} sources were investigated as well. The results secured show that cement and mixtures of it with diatomite, pumice or perlite rapidly yield excellent sorbents with the proper reaction conditions.

  17. Improved Regenerative Sorbent-Compressor Refrigerator

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.

    1992-01-01

    Conceptual regenerative sorbent-compressor refrigerator attains regeneration efficiency and, therefore, overall power efficiency and performance greater than conventional refrigerators. Includes two fluid loops. In one, CH2FCF3 (R134a) ciculates by physical adsorption and desorption in four activated-charcoal sorption compressors. In other, liquid or gas coolant circulated by pump. Wave of regenerative heating and cooling propagates cyclically like peristatic wave among sorption compressors and associated heat exchangers. Powered by electricity, oil, gas, solar heat, or waste heat. Used as air conditioners, refrigerators, and heat pumps in industrial, home, and automotive applications.

  18. A FLUID SORBENT RECYCLING DEVICE FOR INDUSTRIAL FLUID USERS

    EPA Science Inventory

    A roller compression Extractor® that extracts fluids from reusable sorbent pads was evaluated as a method of waste reduction. The extraction device, evaluated for industrial fluid users in New Jersey, was found to be effective in recycling unpleated sorbent pads, especially ...

  19. CHARACTERIZATION OF ADVANCED SORBENTS FOR DRY SO2 CONTROL

    EPA Science Inventory

    The paper discusses the development of new flyash/lime sorbents for removing SO2 from coal-fired flue gas. Flyash/lime weight ratios of 1:1 to 10:1 and several additives to these sorbents for promoting their reactivity were evaluated in a bench-scale reactor simulating conditions...

  20. IODIDE AEROSOL SORBENTS FOR MERCURY CAPTURE IN COMBUSTION EXHAUSTS

    EPA Science Inventory

    Several sorbent processes are being studied for their feasibility for mercury capture. Mercury is different from the other heavy metals as it is not as chemically reactive (due to a filled outer electronic shell), thus making it difficult for sorbents to chemically trap it (a). ...