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Sample records for biocatalytic desulfurization project

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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. PMID:18667551

  6. 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.

  7. Biocatalytic Desulfurization of Petroleum Fact Sheet

    SciTech Connect

    2003-07-01

    Biological desulfurization offers an attractive alternative to conventional treatments due to its mild operating conditions resulting in energy savings, greater sulfur removal, and higher selectivity.

  8. Biocatalytic desulfurization of thiophenic compounds and crude oil by newly isolated bacteria

    PubMed Central

    Mohamed, Magdy El-Said; Al-Yacoub, Zakariya H.; Vedakumar, John V.

    2015-01-01

    Microorganisms possess enormous highly specific metabolic activities, which enable them to utilize and transform nearly every known chemical class present in crude oil. In this context, one of the most studied biocatalytic processes is the biodesulfurization (BDS) of thiophenic sulfur-containing compounds such as benzothiophene (BT) and dibenzothiophene (DBT) in crude oils and refinery streams. Three newly isolated bacterial strains, which were affiliated as Rhodococcus sp. strain SA11, Stenotrophomonas sp. strain SA21, and Rhodococcus sp. strain SA31, were enriched from oil contaminated soil in the presence of DBT as the sole S source. GC-FID analysis of DBT-grown cultures showed consumption of DBT, transient formation of DBT sulfone (DBTO2) and accumulation of 2-hydroxybiphenyl (2-HBP). Molecular detection of the plasmid-borne dsz operon, which codes for the DBT desulfurization activity, revealed the presence of dszA, dszB, and dszC genes. These results point to the operation of the known 4S pathway in the BDS of DBT. The maximum consumption rate of DBT was 11 μmol/g dry cell weight (DCW)/h and the maximum formation rate of 2-HBP formation was 4 μmol/g DCW/h. Inhibition of both cell growth and DBT consumption by 2-HBP was observed for all isolates but SA11 isolate was the least affected. The isolated biocatalysts desulfurized other model DBT alkylated homologs. SA11 isolate was capable of desulfurizing BT as well. Resting cells of SA11 exhibited 10% reduction in total sulfur present in heavy crude oil and 18% reduction in total sulfur present in the hexane-soluble fraction of the heavy crude oil. The capabilities of the isolated bacteria to survive and desulfurize a wide range of S compounds present in crude oil are desirable traits for the development of a robust BDS biocatalyst to upgrade crude oils and refinery streams. PMID:25762990

  9. Biocatalytic desulfurization of diesel oil in an air-lift reactor with immobilized Gordonia nitida CYKS1 cells.

    PubMed

    Lee, In Su; Bae, Hee-Sung; Ryu, Hee Wook; Cho, Kyung-Suk; Chang, Yong Keun

    2005-01-01

    A new type of air-lift reactor with immobilized Gordonia nitida CYKS1 cells on a fibrous support was designed and used for the biocatalytic desulfurization (BDS) of diesel oil. Its performance was evaluated at different phase ratios of the oil to the aqueous medium (or oil phase fractions) and different sucrose concentrations. When the reaction mixture contained 10% diesel oil (v/v), 61-67% of sulfur was removed as the sulfur content decreased from 202-250 to 76-90 mg L(-1) in 72 h. The sulfur content did not decrease any further because the remaining sulfur compounds were recalcitrant to BDS. During the desulfurization, the strain CYKS1 consumed hydrocarbons in the diesel oil, mainly n-alkanes with 10-26 carbons, as carbon source even though an easily available carbon source, sucrose, was supplied. PMID:15932256

  10. 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.

  11. LIFAC sorbent injection desulfurization demonstration project

    SciTech Connect

    Not Available

    1992-03-06

    In December 1990, the US Department of Energy selected 13 projects for funding under the Federal Clean Coal Technology Program (Round III). One of the projects selected was the project sponsored by LIFAC North America, (LIFAC NA), titled LIFAC Sorbent Injection Desulfurization Demonstration Project.'' The host site for this $17 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. In this report, progress for the period July--September 1991 is covered.

  12. 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.

  13. 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. In November 1990, after a ten (10) month negotiation period, LIFAC NA and the US DOE entered into a Cooperative Agreement for the design, construction, and demonstration of the LIFAC system. This report is the fifth Technical Progress Report covering the period October 1, 1991 through the end of December 1991. Due to the power plant's planned outage schedule, and the time needed for engineering, design and procurement of critical equipment, DOE and LIFAC NA agreed to execute the Design Phase of the project in August 1990, with DOE funding contingent upon final signing of the Cooperative Agreement.

  14. LIFAC Sorbent Injection Desulfurization Demonstration Project

    SciTech Connect

    Not Available

    1992-01-01

    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.

  15. 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.

  16. Advanced Flue Gas Desulfurization (AFGD) demonstration project: Volume 2, Project performance and economics. Final technical report

    SciTech Connect

    1996-04-30

    The project objective is to demonstrate removal of 90--95% or more of the SO{sub 2} at approximately one-half the cost of conventional scrubbing technology; and to demonstrate significant reduction of space requirements. In this project, Pure Air has built a single SO{sub 2} absorber for a 528-MWe power plant. The absorber performs three functions in a single vessel: prequencher, absorber, and oxidation of sludge to gypsum. Additionally, the absorber is of a co- current design, in which the flue gas and scrubbing slurry move in the same direction and at a relatively high velocity compared to conventional scrubbers. These features all combine to yield a state- of-the-art SO{sub 2} absorber that is more compact and less expensive than conventional scrubbers. The project incorporated a number of technical features including the injection of pulverized limestone directly into the absorber, a device called an air rotary sparger located within the base of the absorber, and a novel wastewater evaporation system. The air rotary sparger combines the functions of agitation and air distribution into one piece of equipment to facilitate the oxidation of calcium sulfite to gypsum. Additionally, wastewater treatment is being demonstrated to minimize water disposal problems inherent in many high-chloride coals. Bituminous coals primarily from the Indiana, Illinois coal basin containing 2--4.5% sulfur were tested during the demonstration. The Advanced Flue Gas Desulfurization (AFGD) process has demonstrated removal of 95% or more of the SO{sub 2} while providing a commercial gypsum by-product in lieu of solid waste. A portion of the commercial gypsum is being agglomerated into a product known as PowerChip{reg_sign} gypsum which exhibits improved physical properties, easier flowability and more user friendly handling characteristics to enhance its transportation and marketability to gypsum end-users.

  17. LIFAC sorbent injection desulfurization demonstration project. Quarterly report No. 4, July--September 1991

    SciTech Connect

    Not Available

    1992-03-06

    In December 1990, the US Department of Energy selected 13 projects for funding under the Federal Clean Coal Technology Program (Round III). One of the projects selected was the project sponsored by LIFAC North America, (LIFAC NA), titled ``LIFAC Sorbent Injection Desulfurization Demonstration Project.`` The host site for this $17 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. In this report, progress for the period July--September 1991 is covered.

  18. Advanced fuel gas desulfurization (AFGD) demonstration project. Technical progress report No. 19, July 1, 1994--September 30, 1994

    SciTech Connect

    1995-12-01

    The {open_quotes}Advanced Flue Gas Desulfurization (AFGD) Demonstration Project{close_quotes} is a $150.5 million cooperative effort between the U.S. Department of Energy and Pure Air, a general partnership of Air Products and Chemicals, Inc. and Mitsubishi Heavy Industries America, Inc. The AFGD process is one of several alternatives to conventional flue gas desulfurization (FGD) being demonstrated under the Department of Energy`s Clean Coal Technology Demonstration Program. The AFGD demonstration project is located at the Northern Indiana Public Service Company`s Bailly Generating Station, about 12 miles northeast of Gary, Indiana.

  19. Biocatalytic removal of organic sulfur from coal

    SciTech Connect

    Webster, D.A.; Kilbane, J.J. II

    1994-09-09

    The objective is to characterize more completely the biochemical ability of the bacterium, Rhodococcus rhodochrous IGTS8, to cleave carbon-sulfur bonds with emphasis on data that will allow the development of a practical coal biodesulfurization process. Another approach for increasing the desulfurization activity of the IGTS8 cultures is to produce strains genetically that have higher activity. The goal of this part of research is to achieve strain improvement by introducing a stronger promoter using genetic engineering techniques. The promoter regulates the transcription of the genes for the desulfurization enzymes, and a stronger promoter, would up-regulate the expression of these genes, resulting in cells with higher desulfurization activity. Promoter probe vectors are used to identify and isolate promoters from a DNA library of the experimental organism. The major accomplishments have been to obtain high biodesulfurization activity in nonaqueous, media, especially using freeze-dried cells, and to have isolated strong promoters from R. rhodochrous IGTS8 which will be used to engineer the organism to produce strains with higher biocatalytic activity.

  20. Advanced Flue Gas Desulfurization (AFGD) Demonstration Project, A DOE Assessment

    SciTech Connect

    National Energy Technology Laboratory

    2001-08-31

    The AFGD process as demonstrated by Pure Air at the Bailly Station offers a reliable and cost-effective means of achieving a high degree of SO{sub 2} emissions reduction when burning high-sulfur coals. Many innovative features have been successfully incorporated in this process, and it is ready for widespread commercial use. The system uses a single-loop cocurrent scrubbing process with in-situ oxidation to produce wallboard-grade gypsum instead of wet sludge. A novel wastewater evaporation system minimizes effluents. The advanced scrubbing process uses a common absorber to serve multiple boilers, thereby saving on capital through economies of scale. Major results of the project are: (1) SO{sub 2} removal of over 94 percent was achieved over the three-year demonstration period, with a system availability exceeding 99.5 percent; (2) a large, single absorber handled the combined flue gas of boilers generating 528 MWe of power, and no spares were required; (3) direct injection of pulverized limestone into the absorber was successful; (4) Wastewater evaporation eliminated the need for liquid waste disposal; and (5) the gypsum by-product was used directly for wallboard manufacture, eliminating the need to dispose of waste sludge.

  1. LIFAC Sorbent Injection Desulfurization Demonstration Project. Quarterly report No. 12, July--September 1993

    SciTech Connect

    Not Available

    1993-12-31

    In December 1989, the U.S. Department of Energy selected 13 projects for funding under the Federal Clean Coal Technology Program (Round III). One of the projects selected was the project sponsored by LIFAC North America, (LIFAC NA), titled {open_quotes}LIFAC Sorbent Injection Desulfurization Demonstration Project.{close_quotes} 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. The host site for this $22 million, three-phase project is Richmond Power and Light`s Whitewater Valley Unit No. 2 in Richmond, Indiana. The three project phases are: (1) Design; (2A) Long Lead Procurement; (2B) Construction; and (3) Operations. The design phase began on August 8, 1990 and was scheduled to last six months. Phase 2A, long lead procurement, overlaps the design phase and was expected to require about four months to complete. The construction phase was then to continue for another seven months, while the operations phase was scheduled to last about twenty-six months. In November 1990, after a ten (10) month negotiation period, LIFAC NA and the U.S. DOE entered into a Cooperative Agreement for the design, construction, and demonstration of the LIFAC system. This report is the twelfth Technical Progress Report covering the period July 1, 1993 through the end of September 1993. Due to the power plant`s planned outage in March 1991, and the time needed for engineering, design and procurement of critical equipment, DOE and LIFAC NA agreed to execute the Design Phase of the project in August 1990, with DOE funding contingent upon final signing of the Cooperative Agreement.

  2. Biocatalytic portfolio of Basidiomycota.

    PubMed

    Schmidt-Dannert, Claudia

    2016-04-01

    Basidiomycota fungi have received little attention for applications in biocatalysis and biotechnology and remain greatly understudied despite their importance for carbon recycling, ecosystem functioning and medicinal properties. The steady influx of genome data has facilitated detailed studies aimed at understanding the evolution and function of fungal lignocellulose degradation. These studies and recent explorations into the secondary metabolomes have uncovered large portfolios of enzymes useful for biocatalysis and biosynthesis. This review will provide an overview of the biocatalytic repertoires of Basidiomycota characterized to date with the hope of motivation more research into the chemical toolkits of this diverse group of fungi. PMID:26812494

  3. Biocatalytic material comprising multilayer enzyme coated fiber

    DOEpatents

    Kim, Jungbae [Richland, WA; Kwak, Ja Hun [Richland, WA; Grate, Jay W [West Richland, WA

    2009-11-03

    The present invention relates generally to high stability, high activity biocatalytic materials and processes for using the same. The materials comprise enzyme aggregate coatings having high biocatalytic activity and stability useful in heterogeneous environment. These new materials provide a new biocatalytic immobilized enzyme system with applications in bioconversion, bioremediation, biosensors, and biofuel cells.

  4. Advanced Flue Gas Desulfurization (AFGD) Demonstration Project. Technical progress report No. 15, July 1, 1993--September 30, 1993

    SciTech Connect

    Not Available

    1994-08-01

    The goal of this project is to demonstrate that, by combining state-of-the-art technology, highly efficient plant operation and maintenance capabilities and by-product gypsum sales, significant reductions of SO{sub 2} emissions can be achieved at approximately one-half the life cycle cost of a conventional Flue Gas Desulfurization (FGD) system. Further, this emission reduction is achieved without generating solid waste and while minimizing liquid wastewater effluent. Basically, this project entails the design, construction and operation of a nominal 600 MWe AFGD facility to remove SO{sub 2} from coal-fired power plant flue gas at the Northern Indiana Public Service Company`s Bailly Generating Station.

  5. Advanced Flue Gas Desulfurization (AFGD) Demonstration Project. Technical progress report No. 13, January 1, 1993--March 31, 1993

    SciTech Connect

    Not Available

    1994-08-01

    The goal of this project is to demonstrate that, by combining state-of-the-art technology, highly efficient plant operation and maintenance capabilities and by-product gypsum sales, significant reductions of SO{sub 2} emissions can be achieved at approximately one-half the life cycle cost of a conventional Flue Gas Desulfurization (FGD) system. Further, this emission reduction is achieved without generating solid waste and while minimizing liquid wastewater effluent. Basically, this project entails the design, construction and operation of a nominal 600 MWe AFGD facility to remove SO{sub 2} from coal-fired power plant flue gas at the Northern Indiana Public Service Company`s Bailly Generating Station.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. LIFAC Sorbent Injection Desulfurization Demonstration Project. Quarterly report No. 5, October--December 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. In November 1990, after a ten (10) month negotiation period, LIFAC NA and the US DOE entered into a Cooperative Agreement for the design, construction, and demonstration of the LIFAC system. This report is the fifth Technical Progress Report covering the period October 1, 1991 through the end of December 1991. Due to the power plant`s planned outage schedule, and the time needed for engineering, design and procurement of critical equipment, DOE and LIFAC NA agreed to execute the Design Phase of the project in August 1990, with DOE funding contingent upon final signing of the Cooperative Agreement.

  11. 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.

  12. LIFAC Sorbent Injection Desulfurization Demonstration Project. Quarterly report No. 11, April--June 1993

    SciTech Connect

    Not Available

    1993-12-01

    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 a 220 MW coal-fired boiler located at Kristiinankaupunki. At this facility, a slipstream (5000 SCFM) containing the calcined limestone was used to test a small-scale activation reactor (2.5 MW) in which the gas was humidified. Reactor residence times of 3 to 12 seconds resulted in SO{sub 2} removal rates up to 84%. Additional LIFAC pilot-scale tests were conducted at the 8 MW (thermal) level at the Neste Kulloo combustion laboratory to develop the relationships between the important operating and design parameters. Polish low-sulfur coal was burned to achieve 84% S0{sub 2} removal. In 1986, full-scale testing of LIFAC was conducted at Imatran Voima`s Inkoo power plant on a 250 MW utility boiler. An activation chamber was built to treat a flue gas stream representing about 70 MW. Even though the boiler was 250 MW, the 70 MW stream represented about one-half of the flue gas feeding one of the plant`s two ESP`s (i.e., each ESP receives a 125 MW gas stream). This boiler used a 1.5% sulfur coal and sulfur removal was initially 61%. By late 1987, SO{sub 2} removal rates had improved to 76%. In 1988, a LIFAC activation reactor was added to treat an additional 125 MW -- i.e., an entire flue gas/ESP stream-worth of flue gas from this same boiler. This newer activation reactor is achieving 7580% SO{sub 2} removal with Ca:S ratios between 2:1 and 2.5:1. In 1988, the first tests using high-sulfur US coals were run at the pilot scale at the Neste Kulloo Research Center, using a Pittsburgh No. 8 coal containing 3% sulfur. SO{sub 2} removal rates of 77% were achieved at a Ca:S ratio of 2:1. This LIFAC demonstration project will be conducted on a 60 MW boiler burning high-sulfur US coals to demonstrate the commercial application of the LIFAC process to US utilities.

  13. 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

  14. Development of a Desulfurization Strategy for a NOx Adsorber Catalyst

    SciTech Connect

    Tomazic, Dean

    2000-08-20

    Improve NOx regeneration calibration developed in DECSE Phase I project to understand full potential of NOx adsorber catalyst over a range of operating temperatures. Develop and demonstrate a desulfurization process to restore NOx conversion efficiency lost to sulfur contamination. Investigate effect of desulfurization process on long-term performance of the NOx adsorber catalyst.

  15. The Industrial Age of Biocatalytic Transamination

    PubMed Central

    Fuchs, Michael; Farnberger, Judith E; Kroutil, Wolfgang

    2015-01-01

    During the last decade the use of ω-transaminases has been identified as a very powerful method for the preparation of optically pure amines from the corresponding ketones. Their immense potential for the preparation of chiral amines, together with their ease of use in combination with existing biocatalytic methods, have made these biocatalysts a competitor to any chemical methodology for (asymmetric) amination. An increasing number of examples, especially from industry, shows that this biocatalytic technology outmaneuvers existing chemical processes by its simple and flexible nature. In the last few years numerous publications and patents on synthetic routes, mainly to pharmaceuticals, involving ω-transaminases have been published. The review gives an overview of the application of ω-transaminases in organic synthesis with a focus on active pharmaceutical ingredients (APIs) and the developments during the last few years. PMID:26726292

  16. Efficient Biocatalytic Synthesis of Chiral Chemicals.

    PubMed

    Zhang, Zhi-Jun; Pan, Jiang; Ma, Bao-Di; Xu, Jian-He

    2016-01-01

    Chiral chemicals are a group of important chiral synthons for the synthesis of a series of pharmaceuticals, agrochemicals, and fine chemicals. In past decades, a number of biocatalytic approaches have been developed for the green and effective synthesis of various chiral chemicals. However, the practical application of these biocatalytic processes is still hindered by the lack of highly efficient and robust biocatalysts, which usually results in the low volumetric productivity and high cost of the bioprocesses. Further step forward of biocatalysis in industrial application strongly requires the development of versatile and highly efficient biocatalysts, aiming to increase the process efficiency and facilitate the downstream processing. Recently, the fast growth of genome sequences in the database in post-genomic era offers great opportunities for accessing numerous biocatalysts with practical application potential, and the so-called genome mining approach provides time-effective and highly specific strategy for the fast identification of target enzymes with desired properties and outperforms the traditional screening of soil samples for microbial enzyme producers of interest. A number of biocatalytic processes with industrial application potential were developed thereafter. Further development of protein engineering strategies, process optimization, and cooperative work between biologists, organic chemists, and engineers is expected to make biocatalysis technology the first choice approach for the eco-friendly, highly efficient, and cost-effective synthesis of chiral chemicals in the near future. PMID:25537446

  17. 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.

  18. CHEMICAL SPECIATION OF FLUE GAS DESULFURIZATION SLUDGE CONSTITUENTS

    EPA Science Inventory

    This project addresses the problem of flue gas desulfurization (FGD) sludge disposal to land. Specifically, the chemical species of FGD sludge constituents are thermodynamically modeled using the equilibrium constant approach, in an attempt to predict the constituent concentratio...

  19. Passerini Reactions on Biocatalytically Derived Chiral Azetidines.

    PubMed

    Moni, Lisa; Banfi, Luca; Basso, Andrea; Bozzano, Andrea; Spallarossa, Martina; Wessjohann, Ludger; Riva, Renata

    2016-01-01

    The purpose of this study was to explore a series of Passerini reactions on a biocatalytically derived enantiopure azetidine-2-carboxyaldehyde in order to obtain, in a diastereoselective manner, polyfunctionalised derivatives having the potential to be cyclized to chiral bridged bicyclic nitrogen heterocycles. While diastereoselectivity was poor under classical Passerini conditions, a significant increase of diastereoselectivity (up to 76:24) was gained by the use of zinc bromide as promoter. The methodology has a broad scope and yields are always good. PMID:27589709

  20. 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.

  1. For fuel desulfurization: Invite a bioengineered bug to dinner

    SciTech Connect

    Shelley, S.

    1995-05-01

    Last March, Energy BioSystems Corp. (EBC; The Woodlands, Tex.) brought online the world`s first biocatalytic desulfurization (BDS) facility. The $1.5-million pilot plant, located at the St. Louis, MO, research and development facility of Petrolite Corp., is designed to process up to 5 bbl/d to high-sulfur diesel fuel. EBC has partnered with Paris-based Total Raffinage S.A., France`s largest refiner, which is supplying the largest refiner, which is supplying the target diesel. The initial pilot plant was designed to desulfurize middle distillates, because of existing US and European regulations that target sulfur in this petroleum fraction. The firm hopes to have a 10,000-bbl/d commercial unit under construction by 1996. Meanwhile, EBC has partnered with Koch Refining (Wichita, KS) to adapt the process for gasoline, and with Texaco, Inc.`s Exploration and Production Division (Houston, TX) to sweeten sour crude before it reaches the refinery.

  2. Biocatalytic Pathway Selection in Transient Tripeptide Nanostructures.

    PubMed

    Pappas, Charalampos G; Sasselli, Ivan R; Ulijn, Rein V

    2015-07-01

    Structural adaption in living systems is achieved by competing catalytic pathways that drive assembly and disassembly of molecular components under the influence of chemical fuels. We report on a simple mimic of such a system that displays transient, sequence-dependent formation of supramolecular nanostructures based on biocatalytic formation and hydrolysis of self-assembling tripeptides. The systems are catalyzed by α-chymotrypsin and driven by hydrolysis of dipeptide aspartyl-phenylalanine-methyl ester (the sweetener aspartame, DF-OMe). We observed switch-like pathway selection, with the kinetics and consequent lifetime of transient nanostructures controlled by the peptide sequence. In direct competition, kinetic (rather than thermodynamic) component selection is observed. PMID:26014441

  3. Tools and ingredients for the biocatalytic synthesis of metabolites.

    PubMed

    Wohlgemuth, Roland

    2009-09-01

    Metabolic networks have been an interesting starting point not only for the design of synthetic routes in a similar sequence of reactions, e.g., in biomimetic syntheses, but also for assembling a number of biocatalytic steps by preparing the required enzymes and auxiliary reagents. Retrosynthetic analysis involving multiple biocatalytic reactions steps therefore needs to consider the practically realized biocatalytic single steps. The opportunities for route selection are enlarged if novel synthetic reactions connecting easily available starting materials and products are found, and/or both biocatalytic and classical reactions of organic chemistry are utilized. Tools and ingredients for biocatalytic synthesis are of special interest for reactions difficult to achieve by classical organic synthesis. Densely and differentially functionalized small molecules do not allow much space for protecting or activating groups. Biocatalytic reactions have therefore performed well for a number of useful metabolites in enantiopure form to achieve full functionality. Although many well-known metabolites from classical biochemistry have only been prepared in racemic form, it is of fundamental interest to have these available in enantiomerically pure form. Biocatalytic reactions with nature's privileged chiral catalysts appear to be a promising synthetic strategy towards these metabolites, especially when sensitive or stable-isotope-labeled metabolites are to be prepared. The main applications for these metabolites are as references materials in metabolomics, as enzyme substrates for the characterization of metabolic enzyme activities and as potential pharmaceuticals in biomedical research. The use of stable-isotope-labeled metabolites can thereby simplify in vivo applications and metabolic flux analyses. PMID:19777483

  4. Biocatalytic Desulfurization Capabilities of a Mixed Culture during Non-Destructive Utilization of Recalcitrant Organosulfur Compounds

    PubMed Central

    Ismail, Wael; El-Sayed, Wael S.; Abdul Raheem, Abdul Salam; Mohamed, Magdy E.; El Nayal, Ashraf M.

    2016-01-01

    We investigated the biodesulfurization potential of a mixed culture AK6 enriched from petroleum hydrocarbons-polluted soil with dibenzothiophene (DBT) as a sulfur source. In addition to DBT, AK6 utilized the following compounds as sulfur sources: 4-methyldibenzothiophene (4-MDBT), benzothiophene (BT), and 4,6- dimethyldibenzothiophene (4,6-DM-DBT). None of these compounds supported the growth of AK6 as the sole carbon and sulfur source. AK6 could not grow on dibenzylsulfide (DBS) as a sulfur source. The AK6 community structure changed according to the provided sulfur source. The major DGGE bands represented members of the genera Sphingobacterium, Klebsiella, Pseudomonas, Stenotrophomonas, Arthrobacter, Mycobacterium, and Rhodococcus. Sphingobacterium sp. and Pseudomonas sp. were abundant across all cultures utilizing any of the tested thiophenic S-compounds. Mycobacterium/Rhodococcus spp. were restricted to the 4-MDBT culture. The 4-MDBT culture had the highest species richness and diversity. Biodesulfurization of DBT by resting cells of AK6 produced 2-hydroxybiphenyl (2-HBP) in addition to trace amounts of phenylacetate. AK6 transformed DBT to 2-hydroxybiphenyl with a specific activity of 9 ± 0.6 μM 2-HBP g dry cell weight−1 h−1. PCR confirmed the presence in the AK6 community of the sulfur-specific (4S) pathway genes dszB and dszC. Mixed cultures hold a better potential than axenic ones for the development of a biodesulfurization technology. PMID:26973637

  5. Biocatalytic Desulfurization Capabilities of a Mixed Culture during Non-Destructive Utilization of Recalcitrant Organosulfur Compounds.

    PubMed

    Ismail, Wael; El-Sayed, Wael S; Abdul Raheem, Abdul Salam; Mohamed, Magdy E; El Nayal, Ashraf M

    2016-01-01

    We investigated the biodesulfurization potential of a mixed culture AK6 enriched from petroleum hydrocarbons-polluted soil with dibenzothiophene (DBT) as a sulfur source. In addition to DBT, AK6 utilized the following compounds as sulfur sources: 4-methyldibenzothiophene (4-MDBT), benzothiophene (BT), and 4,6- dimethyldibenzothiophene (4,6-DM-DBT). None of these compounds supported the growth of AK6 as the sole carbon and sulfur source. AK6 could not grow on dibenzylsulfide (DBS) as a sulfur source. The AK6 community structure changed according to the provided sulfur source. The major DGGE bands represented members of the genera Sphingobacterium, Klebsiella, Pseudomonas, Stenotrophomonas, Arthrobacter, Mycobacterium, and Rhodococcus. Sphingobacterium sp. and Pseudomonas sp. were abundant across all cultures utilizing any of the tested thiophenic S-compounds. Mycobacterium/Rhodococcus spp. were restricted to the 4-MDBT culture. The 4-MDBT culture had the highest species richness and diversity. Biodesulfurization of DBT by resting cells of AK6 produced 2-hydroxybiphenyl (2-HBP) in addition to trace amounts of phenylacetate. AK6 transformed DBT to 2-hydroxybiphenyl with a specific activity of 9 ± 0.6 μM 2-HBP g dry cell weight(-1) h(-1). PCR confirmed the presence in the AK6 community of the sulfur-specific (4S) pathway genes dszB and dszC. Mixed cultures hold a better potential than axenic ones for the development of a biodesulfurization technology. PMID:26973637

  6. 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)

  7. 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.

  8. Flue gas desulfurization process

    SciTech Connect

    Korosy, L.B.; Senatore, P.J.

    1982-12-28

    A regenerative process for the desulfurization of gas containing from about 100 ppm to about 30 volume percent sulfur dioxide in which the gas is contacted at from about 15/sup 0/ to 80/sup 0/C with an about 0.1 molar to saturated aqueous solution of potassium citrate at a ph of from about 3 to 9 and the contacted solution is then heated to strip sulfur dioxide therefrom.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Microbial desulfurization of coal

    NASA Technical Reports Server (NTRS)

    Dastoor, M. N.; Kalvinskas, J. J.

    1978-01-01

    Experiments indicate that several sulfur-oxidizing bacteria strains have been very efficient in desulfurizing coal. Process occurs at room temperature and does not require large capital investments of high energy inputs. Process may expand use of abundant reserves of high-sulfur bituminous coal, which is currently restricted due to environmental pollution. On practical scale, process may be integrated with modern coal-slurry transportation lines.

  14. Nanopropulsion by biocatalytic self-assembly.

    PubMed

    Leckie, Joy; Hope, Alexander; Hughes, Meghan; Debnath, Sisir; Fleming, Scott; Wark, Alastair W; Ulijn, Rein V; Haw, Mark D

    2014-09-23

    A number of organisms and organelles are capable of self-propulsion at the micro- and nanoscales. Production of simple man-made mimics of biological transportation systems may prove relevant to achieving movement in artificial cells and nano/micronscale robotics that may be of biological and nanotechnological importance. We demonstrate the propulsion of particles based on catalytically controlled molecular self-assembly and fiber formation at the particle surface. Specifically, phosphatase enzymes (acting as the engine) are conjugated to a quantum dot (the vehicle), and are subsequently exposed to micellar aggregates (fuel) that upon biocatalytic dephosphorylation undergo fibrillar self-assembly, which in turn causes propulsion. The motion of individual enzyme/quantum dot conjugates is followed directly using fluorescence microscopy. While overall movement remains random, the enzyme-conjugates exhibit significantly faster transport in the presence of the fiber forming system, compared to controls without fuel, a non-self-assembling substrate, or a substrate which assembles into spherical, rather than fibrous structures upon enzymatic dephosphorylation. When increasing the concentration of the fiber-forming fuel, the speed of the conjugates increases compared to non-self-assembling substrate, although directionality remains random. PMID:25162764

  15. Coal desulfurization by cyclonic whirl

    SciTech Connect

    Jianguo, Y.; Wenjun, Z.; Yuling, W.

    1999-07-01

    The crux of coal desulfurization is how to improve separation efficiency for 3--0.1mm materials. Cyclonic whirl produce centrifugal force and shearing force, heavy medium cyclone uses former, and cyclone flotation column uses both of them. A new system with heavy medium cyclone and cyclone flotation column is provided and testified to be very efficient in commercial desulfurization.

  16. 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.

  17. DISPOSAL OF FLUE GAS DESULFURIZATION WASTES: EPA SHAWNEE FIELD EVALUATION

    EPA Science Inventory

    The report summarizes results of the flue gas desulfurization (FGD) waste disposal field evaluation project sponsored by EPA at TVA's Shawnee steam plant, Paducah, KY. This pilot-scale project, initiated in 1974 and completed in September 1980, evaluated methods and costs for dis...

  18. The Natural History of Biocatalytic Mechanisms

    PubMed Central

    Nath, Neetika; Mitchell, John B. O.; Caetano-Anollés, Gustavo

    2014-01-01

    Phylogenomic analysis of the occurrence and abundance of protein domains in proteomes has recently showed that the α/β architecture is probably the oldest fold design. This holds important implications for the origins of biochemistry. Here we explore structure-function relationships addressing the use of chemical mechanisms by ancestral enzymes. We test the hypothesis that the oldest folds used the most mechanisms. We start by tracing biocatalytic mechanisms operating in metabolic enzymes along a phylogenetic timeline of the first appearance of homologous superfamilies of protein domain structures from CATH. A total of 335 enzyme reactions were retrieved from MACiE and were mapped over fold age. We define a mechanistic step type as one of the 51 mechanistic annotations given in MACiE, and each step of each of the 335 mechanisms was described using one or more of these annotations. We find that the first two folds, the P-loop containing nucleotide triphosphate hydrolase and the NAD(P)-binding Rossmann-like homologous superfamilies, were α/β architectures responsible for introducing 35% (18/51) of the known mechanistic step types. We find that these two oldest structures in the phylogenomic analysis of protein domains introduced many mechanistic step types that were later combinatorially spread in catalytic history. The most common mechanistic step types included fundamental building blocks of enzyme chemistry: “Proton transfer,” “Bimolecular nucleophilic addition,” “Bimolecular nucleophilic substitution,” and “Unimolecular elimination by the conjugate base.” They were associated with the most ancestral fold structure typical of P-loop containing nucleotide triphosphate hydrolases. Over half of the mechanistic step types were introduced in the evolutionary timeline before the appearance of structures specific to diversified organisms, during a period of architectural diversification. The other half unfolded gradually after organismal

  19. 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.

  20. Biocatalytic Refining of Soybean Oil into Cosmeceutical Ingredients

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our mission is to develop new, value-added uses for commodity crops and oils. We chose to fulfill this mission while adhering as closely as possible to the tenants of “green” chemistry. We have developed patented, all-natural oils called Feruloyl Soy Glycerols (FSG) from the biocatalytic transester...

  1. 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.

  2. SHAWNEE FLUE GAS DESULFURIZATION COMPUTER MODEL USERS MANUAL

    EPA Science Inventory

    The manual describes a Shawnee flue gas desulfurization (FGD) computer model and gives detailed instructions for its use. The model, jointly developed by Bechtel National, Inc. and TVA (in conjunction with the EPA-sponsored Shawnee test program), is capable of projecting prelimin...

  3. 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.

  4. 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.

  5. Enzymatic desulfurization of coal

    SciTech Connect

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

    1989-12-14

    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.

  6. New reagents for coal desulfurization. Final technical report, September 1, 1990--August 31, 1991

    SciTech Connect

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

    1991-12-31

    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.

  7. Microscale technology and biocatalytic processes: opportunities and challenges for synthesis.

    PubMed

    Wohlgemuth, Roland; Plazl, Igor; Žnidaršič-Plazl, Polona; Gernaey, Krist V; Woodley, John M

    2015-05-01

    Despite the expanding presence of microscale technology in chemical synthesis and energy production as well as in biomedical devices and analytical and diagnostic tools, its potential in biocatalytic processes for pharmaceutical and fine chemicals, as well as related industries, has not yet been fully exploited. The aim of this review is to shed light on the strategic advantages of this promising technology for the development and realization of biocatalytic processes and subsequent product recovery steps, demonstrated with examples from the literature. Constraints, opportunities, and the future outlook for the implementation of these key green engineering methods and the role of supporting tools such as mathematical models to establish sustainable production processes are discussed. PMID:25836031

  8. A new approach to the deposition of nanostructured biocatalytic films

    NASA Astrophysics Data System (ADS)

    Troitsky, V. I.; Berzina, T. S.; Pastorino, L.; Bernasconi, E.; Nicolini, C.

    2003-06-01

    In the present work, monolayer engineering was used to fabricate biocatalytic nanostructured thin films based on the enzyme penicillin G acylase. The biocatalytic films with enhanced characteristics were produced by the deposition of alternate-layer assemblies with a predetermined structure using a combination of Langmuir-Blodgett and adsorption techniques. The value of enzyme activity and the level of protein detachment were measured in dependence on the variation of film composition and on the sequence of layer alternation. As a result, highly active and stable structures were found, which could be promising candidates for practical applications. The method of modification of the deposition method to provide continuous film formation on large-area supports is discussed.

  9. Desulfurization apparatus and method

    SciTech Connect

    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.

  10. Evaluation of sulfur-reducing microorganisms for organic desulfurization

    SciTech Connect

    Miller, K.W. . Dept. of Biological Sciences)

    1991-01-01

    Because a substantial portion of the sulfur in Illinois coal is organically bound sulfur, microbial desulfurization of sulfidic and thiophenic functionalities holds great potential for complementing pyritic sulfur removal. The release of H{sub 2}S from anaerobic systems such as the gut, sewage, and marine and freshwater sediments, is a common occurrence and the role of microorganisms in this process has long been recognized. The principal goals of our project are: to obtain anaerobic microbial cultures that produce H{sub 2}S from compounds representative of the organosulfur functionalities in coal; to optimize this activity; to evaluate the effectiveness of using these cultures to remove organic sulfur from Illinois coal. Our immediate objectives for this year are the following: To obtain additional cultures from coal mine waste and municipal sewage sludge, two environments previously unexplored by our laboratory; to continue optimizing activity in cultures that desulfurize model compounds, including identification of individual microbial species; to expand coal desulfurization experiments to include additional coals; and, to address the recently discovered problem of sulfide sorbing to coal. This quarter we report on the following: (1) desulfurization experiments with IBC-101; (2) quantitative experiments dealing with dibenzyldisulfide (DBDS) degradation in mixed cultures derived from petroleum wastes; (3) thiophene, dibenzothiophene (DBT), DBT sulfone, or phenyl sulfone as substrates for pure cultures of sulfate-reducing bacteria. 36 refs., 1 fig. 6 tabs.

  11. Desulfurization from Bauxite Water Slurry (BWS) Electrolysis

    NASA Astrophysics Data System (ADS)

    Gong, Xuzhong; Ge, Lan; Wang, Zhi; Zhuang, Siyuan; Wang, Yuhua; Ren, Lihui; Wang, Mingyong

    2016-02-01

    Feasibility of high-sulfur bauxite electrolysis desulfurization was examined using the electrochemical characterization, XRD, DTA, and FTIR. The cyclic voltammetry curves indicated that bauxite water slurry (BWS) electrolysis in NaOH system was controlled by diffusion. Additionally, the desulfurization effect of NaCl as the electrolyte was significantly better than that of NaOH as an electrolyte. As the stirring rate increased, the desulfurization ratio in NaCl system was not increased obviously, while the desulfurization ratio in NaOH system increased significantly, indicating further that electrolysis desulfurization in NaOH solution was controlled by diffusion. According to XRD, DTA, and FTIR analysis, the characteristic peaks of sulfur-containing phase in bauxite after electrolysis weakened or disappeared, indicating that the pyrite in bauxite was removed from electrolysis. Finally, the electrolytic desulfurization technology of bauxite was proposed based on the characteristics of BWS electrolysis.

  12. Biocatalytic photosynthesis with water as an electron donor.

    PubMed

    Ryu, Jungki; Nam, Dong Heon; Lee, Sahng Ha; Park, Chan Beum

    2014-09-15

    Efficient harvesting of unlimited solar energy and its conversion into valuable chemicals is one of the ultimate goals of scientists. With the ever-increasing concerns about sustainable growth and environmental issues, numerous efforts have been made to develop artificial photosynthetic process for the production of fuels and fine chemicals, thus mimicking natural photosynthesis. Despite the research progress made over the decades, the technology is still in its infancy because of the difficulties in kinetic coupling of whole photocatalytic cycles. Herein, we report a new type of artificial photosynthesis system that can avoid such problems by integrally coupling biocatalytic redox reactions with photocatalytic water splitting. We found that photocatalytic water splitting can be efficiently coupled with biocatalytic redox reactions by using tetracobalt polyoxometalate and Rh-based organometallic compound as hole and electron scavengers, respectively, for photoexcited [Ru(bpy)3](2+). Based on these results, we could successfully photosynthesize a model chiral compound (L-glutamate) using a model redox enzyme (glutamate dehydrogenase) upon in situ photoregeneration of cofactors. PMID:25088448

  13. Enzyme-polymer composites with high biocatalytic activity and stability

    SciTech Connect

    Kim, Jungbae; Kosto, Timothy J.; Manimala, Joseph C.; Nauman, E B.; Dordick, Jonathan S.

    2004-08-22

    We have applied vacuum-spraying and electrospinning to incorporate an enzyme into a polymer matrix, creating a novel and highly active biocatalytic composite. As a unique technical approach, enzymes were co-dissolved in toluene with polymers, and the solvent was then rapidly removed by injecting the mixture into a vacuum chamber or by electrospinning. Subsequent crosslinking of the enzyme with glutaraldehyde resulted in stable entrapped enzyme within the polymeric matrices. For example, an amorphous composite of alpha-chymotrypsin and polyethylene showed no significant loss of enzymatic activity in aqueous buffer for one month. Nanofibers of alpha-chymotrypsin and polystyrene also showed no decrease in activity for more than two weeks. The normalized activity of amorphous composite in organic solvents was 3-13 times higher than that of native alpha-chymotrypsin. The activity of nanofibers was 5-7 times higher than that of amorphous composite in aqueous buffer solution. The composites of alpha-chymotrypsin and polymers demonstrate the feasibility of obtaining a wide variety of active and stable biocatalytic materials with many combinations of enzymes and polymers.

  14. Biochemical and biocatalytic characterization of 17 novel halohydrin dehalogenases.

    PubMed

    Koopmeiners, Julia; Halmschlag, Birthe; Schallmey, Marcus; Schallmey, Anett

    2016-09-01

    Halohydrin dehalogenases are rare but catalytically remarkable enzymes since they are able to form novel C-C, C-O, C-N, or C-S bonds. Very recently, a motif-based sequence database mining approach resulted in the identification of 37 novel halohydrin dehalogenase enzymes, many of them exhibiting only low sequence similarity to previously known halohydrin dehalogenases. In an attempt to explore the biocatalytic potential of these newly identified enzymes, 17 representatives from all six phylogenetic subtypes were heterologously produced in Escherichia coli, purified and characterized to determine their substrate scopes in the dehalogenation and epoxide ring-opening reaction. Several enzymes with broad substrate spectra were identified exhibiting high activities towards a selection of typical substrates. Moreover, four halohydrin dehalogenases were found to be significantly more thermostable than the previously known HheC from Agrobacterium radiobacter AD1. Investigation of the enzymes' stereoselectivity in the dehalogenation of racemic 2-chloro-1-phenylethanol revealed that their stereopreference correlates with the phylogenetic placing of the enzymes in subtypes A through G. Furthermore, the biocatalytic potential of these novel halohydrin dehalogenases was investigated in the preparation of ethyl 4-cyano-3-hydroxybutyrate, a statin side-chain precursor. Though none of the active enzymes selectively formed the required (R)-enantiomer, several halohydrin dehalogenases were identified with significantly higher activity in the conversion compared to HheC, making them promising candidates for this industrially relevant reaction. PMID:27052376

  15. 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.

  16. Desulfurization of pure coal macerals

    SciTech Connect

    Hippo, E.J. ); Crelling, J.C. )

    1988-06-01

    The objectives of this study were to modify the present density gradient centrifugation (DGC) techniques for coal macerals to obtain 10-20 grams of target maceral concentrates and to determine the reactivity or ease of removing the organic sulfur in the various macerals with supercritical methanol extraction. Although the chemistry needed for this objective is not difficult, the accumulation of 10 to 20 gram quantities of ''pure'' petrographically verified single maceral concentrates has not been possible until now. The results of recent work have demonstrated that the individual macerals can be separated and verified. The accumulation of much larger quantities than have previously been separated was a problem that has been overcome by pre-concentrating target macerals at their density cut points. Supercritical fluid extraction of coals has previously been reported as a method in the production of liquid fuel products from coal under mild conditions and as a medium for selective desulfurization of coal. Alcohols are expected to exhibit greater solubility for polar organic molecules due to hydrogen bonding and dipole attractive forces, also providing the opportunity for chemical reactions during the extraction due to the nucleophilicity of the alcohol oxygen and the tendency to act as a hydrogen donor. In addition, enol rearrangements may play a role in desulfurization. As previously reported different supercritical reaction conditions produced different extents of desulfurization of coals (33.9 - 65.7%). These variable desulfurizations are probably a result of differences in extents of conversion of the pyritic sulfur (to various alteration products, such as pyrrhotite), as well as organic sulfur functionalities (thiophenol, sulfide, and thiopenes) to light gases such as dimethylsulfide, hydrogen sulfide, and methylmercaptons.

  17. Desulfurization of pure coal macerals

    SciTech Connect

    Hippo, E.J.; Crelling, J.C. )

    1988-01-01

    The objectives of this study were to modify the present density gradient centrifugation (DGC) techniques for coal macerals to obtain 10-20 grams of target maceral concentrates and to determine the reactivity or ease of removing the organic sulfur in the various macerals with supercritical methanol extraction. Although the chemistry needed for this objective is not difficult, the accumulation of 10 to 20 gram quantities of pure petrographically verified single maceral concentrates has not been possible until now. The results of recent work have demonstrated that the individual macerals can be separated and verified. The accumulation of much larger quantities than have previously been separated was a problem that has been overcome by pre-concentrating target macerals at their density cut points. Supercritical fluid extraction of coals has previously been reported as a method in the production of liquid fuel products from coal under mild conditions and as a medium for selective desulfurization of coal. Alcohols are expected to exhibit greater solubility for polar organic molecules due to hydrogen bonding and dipole attractive forces, also providing the opportunity for chemical reactions during the extraction due to the nucleophilicity of the alcohol oxygen and the tendency to act as a hydrogen donor. In addition, enol rearrangements may play a role in desulfurization. As previously reported different supercritical reaction conditions produced different extents of desulfurization of coals (33.9 - 65.7%). These variable desulfurizations are probably a result of differences in extents of conversion of the pyritic sulfur (to various alteration products, such as pyrrhotite), as well as organic sulfur functionalities (thiophenol, sulfide, and thiophenes) to light gases such as dimethylsulfide, hydrogen sulfide, and methylmercaptons.

  18. 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.

  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. 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.

  1. 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

  2. Biocompatible enzymatic roller pens for direct writing of biocatalytic materials: "do-it-yourself" electrochemical biosensors.

    PubMed

    Bandodkar, Amay J; Jia, Wenzhao; Ramírez, Julian; Wang, Joseph

    2015-06-01

    The development of enzymatic-ink-based roller pens for direct drawing of biocatalytic sensors, in general, and for realizing renewable glucose sensor strips, in particular, is described. The resulting enzymatic-ink pen allows facile fabrication of high-quality inexpensive electrochemical biosensors of any design by the user on a wide variety of surfaces having complex textures with minimal user training. Unlike prefabricated sensors, this approach empowers the end user with the ability of "on-demand" and "on-site" designing and fabricating of biocatalytic sensors to suit their specific requirement. The resulting devices are thus referred to as "do-it-yourself" sensors. The bio-active pens produce highly reproducible biocatalytic traces with minimal edge roughness. The composition of the new enzymatic inks has been optimized for ensuring good biocatalytic activity, electrical conductivity, biocompati-bility, reproducible writing, and surface adherence. The resulting inks are characterized using spectroscopic, viscometric, electrochemical, thermal and microscopic techniques. Applicability to renewable blood glucose testing, epidermal glucose monitoring, and on-leaf phenol detection are demonstrated in connection to glucose oxidase and tyrosinase-based carbon inks. The "do-it-yourself" renewable glucose sensor strips offer a "fresh," reproducible, low-cost biocatalytic sensor surface for each blood test. The ability to directly draw biocatalytic conducting traces even on unconventional surfaces opens up new avenues in various sensing applications in low-resource settings and holds great promise for diverse healthcare, environmental, and defense domains. PMID:25721554

  3. A Reusable Calcium-Based Sorbent for Desulfurizing Hot Coal Gas

    SciTech Connect

    Wheelock, T.D.; Hasler, D.J.L.

    2002-09-19

    The overall objective of this project has been to develop a superior, regenerable, calcium-based sorbent for desulfurizing hot coal gas. The sorbent should be strong, durable, inexpensive to manufacture, and capable of being reused many times. To achieve these objectives the project has focused on the development of the very promising core-in-shell sorbent.

  4. Biocatalytic production of novel glycolipids with cellodextrin phosphorylase.

    PubMed

    Tran, Hai Giang; Desmet, Tom; Saerens, Karen; Waegeman, Hendrik; Vandekerckhove, Stéphanie; D'hooghe, Matthias; Van Bogaert, Inge; Soetaert, Wim

    2012-07-01

    Glycolipids have gained increasing attention as natural surfactants with a beneficial environmental profile. They are typically produced by fermentation, which only gives access to a limited number of structures. Here we describe the biocatalytic production of novel glycolipids with the cellodextrin phosphorylase from Clostridium stercorarium. This enzyme was found to display a broad donor and acceptor specificity, allowing the synthesis of five different products. Indeed, using either α-glucose 1-phosphate or α-galactose 1-phosphate as glycosyl donor, sophorolipid as well as glucolipid could be efficiently glycosylated. The transfer of a glucosyl moiety afforded a mixture of products that precipitated from the solution, resulting in near quantitative yields. The transfer of a galactosyl moiety, in contrast, generated a single product that remained in solution at thermodynamic equilibrium. These glycolipids not only serve as a new class of biosurfactants, but could also have applications in the pharmaceutical and nanomaterials industries. PMID:22000964

  5. Using Inorganic Nanomaterials to Endow Biocatalytic Systems with Unique Features.

    PubMed

    Lin, Youhui; Chen, Zhengwei; Liu, Xiang Yang

    2016-04-01

    The rapid growth in nanotechnology and biotechnology offers a wealth of opportunities for the combination of natural enzymes with different kinds of nanomaterial. Here, we highlight recent advances in constructing nanomaterial-incorporated enzymes that integrate the specific recognition and biocatalytic properties of enzymes with the attractive electronic, optical, magnetic, and catalytic properties of nanomaterials. These composite materials have some extra features that are not possessed by the enzymes themselves, such as electron transfer mediated by nanoparticles, enzyme delivery, remote activation and/or deactivation of enzymatic activity, and fabrication of catalytic entities with complementary functions. Additionally, we describe briefly the current challenges and future development of unique enzyme-nanomaterial hybrid systems. We hope that this review will help to accelerate further progress in this promising field. PMID:26822167

  6. Nonaqueous biocatalytic degradation of a nerve gas mimic.

    PubMed

    Yang, F; Wild, J R; Russell, A J

    1995-01-01

    Organophosphorus hydrolase has been shown to be an effective catalyst for the continuous decontamination of a nerve agent in a continuous gas phase reactor. Very small quantities of the enzyme are sufficient to enable detoxification of low concentrations of the nerve agent for extended periods of time. In the case where the nerve agent is at high concentrations (a liquid), the enzyme has also been shown to be active in biphasic mixtures of a solvent with water. The activity and specificity of the enzyme in both environments (continuous gas phase and biphasic mixture) obey classical models of enzyme kinetics. The activity of the enzyme in such extreme environments enables optimization of systems capable of continuous gas or liquid phase biocatalytic degradation of highly toxic chemicals. PMID:7654313

  7. High temperature desulfurization using molten salt carbonate

    SciTech Connect

    Yoshida, Nobuhiro; Iwahashi, Takashi; Kosaka, Hitoshi; Tsuji, Kiyoshi; Yoshikawa, Kunio; Yamashita, Keijiro; Murata, Keiji; Hori, Michio

    1998-07-01

    A new desulfurization process using molten salt carbonate as an absorber is proposed. Main feature of this process is its high operating temperature (600{approximately}800 C) as well as the possibility of simultaneous desulfurization and dechlorination. Some chemical equilibrium calculations and basic experiments of this process have been done as the first step of basic theoretical investigations for this new gas cleanup concept. It is confirmed from this calculation that this new gas cleanup concept has enough ability of desulfurization and regeneration of molten salt carbonate.

  8. 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

  9. Biocatalytic potential of vanillin aminotransferase from Capsicum chinense

    PubMed Central

    2014-01-01

    Background The conversion of vanillin to vanillylamine is a key step in the biosynthetic route towards capsaicinoids in pungent cultivars of Capsicum sp. The reaction has previously been annotated to be catalysed by PAMT (putative aminotransferase; [GenBank: AAC78480.1, Swiss-Prot: O82521]), however, the enzyme has previously not been biochemically characterised in vitro. Results The biochemical activity of the transaminase was confirmed by direct measurement of the reaction with purified recombinant enzyme. The enzyme accepted pyruvate, and oxaloacetate but not 2-oxoglutarate as co-substrate, which is in accordance with other characterised transaminases from the plant kingdom. The enzyme was also able to convert (S)-1-phenylethylamine into acetophenone with high stereo-selectivity. Additionally, it was shown to be active at a broad pH range. Conclusions We suggest PAMT to be renamed to VAMT (vanillin aminotransferase, abbreviation used in this study) as formation of vanillin from vanillylamine could be demonstrated. Furthermore, due to high stereoselectivity and activity at physiological pH, VAMT is a suitable candidate for biocatalytic transamination in a recombinant whole-cell system. PMID:24712445

  10. Biocatalytic nerve agent detoxification in fire fighting foams.

    PubMed

    LeJeune, K E; Russell, A J

    1999-03-20

    Current events across the globe necessitate rapid technological advances to combat the epidemic of nerve agent chemical weapons. Biocatalysis has emerged as a viable tool in the detoxification of organophosphorus neurotoxins, such as the chemical weapons VX and sarin. Efficient detoxification of contaminated equipment, machinery, and soils are of principal concern. This study describes the incorporation of a biocatalyst (organophosphorus hydrolase, E.C. 3.1.8.1) into conventional formulations of fire fighting foam. The capacity of fire fighting foams to decrease volatilization of contained contaminants, increase surface wettability, and control the rate of enzyme delivery to large areas makes them useful vehicles for enzyme application at surfaces. The performance of enzyme containing foams has been shown to be not only reproducible but also predictable. An empirical model provides reasonable estimations for the amounts of achievable surface decontamination as a function of the important parameters of the system. Theoretical modeling illustrates that the enzyme-containing foam is capable of extracting agent from the surface and is catalytically active at the foam-surface interface and throughout the foam itself. Biocatalytic foam has proven to be an effective, "environmentally friendly" means of surface and soil decontamination. PMID:10068213

  11. Effectiveness Factors and Conversion in a Biocatalytic Membrane Reactor

    PubMed Central

    Godongwana, Buntu

    2016-01-01

    Analytical expressions of the effectiveness factor of a biocatalytic membrane reactor, and its asymptote as the Thiele modulus becomes large, are presented. The evaluation of the effectiveness factor is based on the solution of the governing equations for solute transport in the two regions of the reactor, i.e. the lumen and the matrix (with the biofilm immobilized in the matrix). The lumen solution accounts for both axial diffusion and radial convective flow, while the matrix solution is based on Robin-type boundary conditions. The effectiveness factor is shown to be a function of the Thiele modulus, the partition coefficient, the Sherwood number, the Peclet number, and membrane thickness. Three regions of Thiele moduli are defined in the effectiveness factor graphs. These correspond with reaction rate limited, internal-diffusion limited, and external mass transfer limited solute transport. Radial convective flows were shown to only improve the effectiveness factor in the region of internal diffusion limitation. The assumption of first order kinetics is shown to be applicable only in the Thiele modulus regions of internal and external mass transfer limitation. An iteration scheme is also presented for estimating the effectiveness factor when the solute fractional conversion is known. The model is validated with experimental data from a membrane gradostat reactor immobilised with Phanerochaete chrysosporium for the production of lignin and manganese peroxidases. The developed model and experimental data allow for the determination of the Thiele modulus at which the effectiveness factor and fractional conversion are optimal. PMID:27104954

  12. BENCH SCALE DEVELOPMENT OF MEYERS PROCESS FOR COAL DESULFURIZATION

    EPA Science Inventory

    The report gives results of coal desulfurization experiments to determine the feasibility and advantages of combining gravity separation of coal with chemical desulfurization. The investigations led to the definition of the Gravichem Process, a combination physical/chemical coal ...

  13. 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.

  14. Biocatalytic Conversion of Avermectin to 4"-Oxo-Avermectin: Characterization of Biocatalytically Active Bacterial Strains and of Cytochrome P450 Monooxygenase Enzymes and Their Genes

    PubMed Central

    Jungmann, Volker; Molnár, István; Hammer, Philip E.; Hill, D. Steven; Zirkle, Ross; Buckel, Thomas G.; Buckel, Dagmar; Ligon, James M.; Pachlatko, J. Paul

    2005-01-01

    4"-Oxo-avermectin is a key intermediate in the manufacture of the agriculturally important insecticide emamectin benzoate from the natural product avermectin. Seventeen biocatalytically active Streptomyces strains with the ability to oxidize avermectin to 4"-oxo-avermectin in a regioselective manner have been discovered in a screen of 3,334 microorganisms. The enzymes responsible for this oxidation reaction in these biocatalytically active strains were found to be cytochrome P450 monooxygenases (CYPs) and were termed Ema1 to Ema17. The genes for Ema1 to Ema17 have been cloned, sequenced, and compared to reveal a new subfamily of CYPs. Ema1 to Ema16 have been overexpressed in Escherichia coli and purified as His-tagged recombinant proteins, and their basic enzyme kinetic parameters have been determined. PMID:16269732

  15. 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.

  16. 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.

  17. A bio-catalytically driven Janus mesoporous silica cluster motor with magnetic guidance.

    PubMed

    Ma, Xing; Sanchez, Samuel

    2015-03-28

    A bio-catalytic Janus motor based on the mesoporous silica cluster (JMSC) is fabricated. Chemically conjugated catalase triggers the decomposition of H2O2 to produce driving force by bubble propulsion, while a metallic (Ni) coating layer allows for magnetic guidance of the motor. The JMSC motor can act as a delivery vehicle with cargo loading inside its mesopores. PMID:25407318

  18. 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.

  19. Desulfurization of coal using formic acid

    SciTech Connect

    Wang, G.; Perkson, A.; Trass, O.

    1995-12-31

    Desulfurization of preoxidized Illinois Basin coal, IBC-108, with formic acid has been studied using a factorial design with four process variables: temperature, reaction time, amount of formic acid and amount of hydrogen peroxide used in the preoxidation step. Maximum total removal of 74% sulfur was achieved by pre-treatment of 5 g coal with 10 ml hydrogen peroxide followed by reaction with 7.5 ml formic acid at 500 C, in a 300 ml batch reactor. The results show that oxidation with hydrogen peroxide significantly enhances the level of desulfurization that may be obtained with subsequent chemical or thermal treatments.

  20. Fluidized bed coal desulfurization. Final Report

    SciTech Connect

    Ravindram, M.

    1983-08-01

    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.

  1. Environmental significance of biocatalytic conversion of low grade oils

    SciTech Connect

    Lin, M.S.; Premuzic, E.T.; Lian, H.; Zhou, W.M.; Yablon, J.

    1996-09-01

    Studies dealing with the interactions between extremophilic microorganisms and crude oils have led to the identification of biocatalysts which through multiple biochemical reactions catalyze desulfurization, denitrogenation, and demetalation reactions in oils. Concurrently, the oils are also converted to lighter oils. These complex biochemical reactions have served as models in the development of the crude oil bioconversion technology to be applied prior to the treatment of oils by conventional chemical processes. In practical terms, this means that the efficiency of the existing technology is being enhanced. For example, the recently introduced additional regulation for the emission of nitrogen oxides in some states restricts further the kinds of oils that may be used in burners. The biocatalysts being developed in this laboratory selectively interact with nitrogen compounds, i.e. basic and neutral types present in the oil and, hence, affect the fuel NOx production. This, in turn, has a cost-efficient influence on the processed oils and their consumption. In this paper, these cost-efficient and beneficial effects will be discussed in terms of produced oils, the lowering of sulfur and nitrogen contents, and the effect on products, as well as the longevity of catalysts due to the removal of heteroatoms and metal containing compounds found in crudes.

  2. Bench-scale development of mild gasification char desulfurization. Technical report, 1 March--31 May 1994

    SciTech Connect

    Knight, R.A.

    1994-09-01

    The goal of this project is to scale up a process, developed under a previous ICCI grant, for desulfurization of mild gasification char by treatment with hydrogen-rich process-derived fuel gas at 650--760 C and 7--15 atm. The char can be converted into a low-sulfur metallurgical form coke. In the prior study, IBC-105 coal with 4.0 wt% sulfur was converted to chars with less than 1.0 wt% sulfur in a laboratory-scale batch reactor. The susceptibility of the char to desulfurization was correlated with physicochemical char properties and mild gasification conditions. Acid pretreatment of the coal prior to mild gasification was also shown to significantly enhance subsequent sulfur removal. In this study, IGT is conducting continuous bench-scale tests in a 1-lb/h fluidized-bed reactor to determine the preferred process conditions and obtain steady-state data necessary for process design and scale-up. The desulfurized chars are to be used to produce low-sulfur form coke, which will be evaluated for density, reactivity, and strength properties relevant to utilization in blast furnaces. This quarter, 2,500 g of mild gasification char was produced from untreated IBC-105 coal in the bench-scale reactor. Half of this char will be subjected to sulfuric acid treatment to enhance subsequent desulfurization. Char-producing runs were also initiated with acid-pretreated coal, which will produce about 1,250 g of char.

  3. Scale-Up of Advanced Hot-Gas Desulfurization Sorbents

    SciTech Connect

    Jothimurugesan, K.; Gangwal, Santosh K.

    1996-10-14

    The overall objective of this project is to develop regenerable sorbents for hot gas desulfurization in IGCC systems. The specific objective of the project is to develop durable advanced sorbents that demonstrate a strong resistance to attrition and chemical deactivation, and high activity at temperatures as low as 343 C (650 F). A number of formulations will be prepared and screened in a 1/2-inch fixed bed reactor at high pressure (1 to 20 atm) and high temperatures using simulated coal-derived fuel-gases. Screening criteria will include, chemical reactivity, stability, and regenerability over the temperature range of 343 C to 650 C. After initial screening, at least 3 promising formulations will be tested for 25-30 cycles of absorption and regeneration. One of the superior formulations with the best cyclic performance will be selected for investigating scale up parameters. The scaled-up formulation will be tested for long term durability and chemical reactivity.

  4. 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.

  5. 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.

  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. COMMERCIAL UTILITY FLUE GAS DESULFURIZATION SYSTEMS

    EPA Science Inventory

    The article discusses the current status of commercial flue gas desulfurization (FGD) processes applied to coal-fired utility boilers in the U.S. Major objectives of the work were to examine the impacts of the 1979 New Source Performance Standards on FGD system design and operati...

  8. 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.

  9. [Performance of desulfurizing absorbent of roasted navajoite].

    PubMed

    Chen, Fang; Yang, Chun-ping; Gan, Hai-ming; Wu, Ting; Chen, Hai-lin; Chen, Hong; Xu, Ke-hui; Xie, Geng-xin

    2010-04-01

    An innovative flue gas desulfurization (FGD) coupling process was proposed in this study to overcome the problems in wet-type limestone/lime processes which include fouling, clogging, and difficulty of selling the by-products and the problems in traditional process for vanadium extraction from navajoite ore such as excessive consumption of sulfuric acid and emissions of pollutants. The performance of a jet bubbling reactor (JBR) at pilot-scale was evaluated using navajoite ore produced in the process of extracting vanadium pentoxide as desulfurization absorbent. Results showed that navajoite ore slurry achieved better desulfurization performance than limestone slurry. When the inlet flue gas pressure drop was 3.0 kPa, the gas flow was about 2350 m3 x h(-1) and the pH of the navajoite ore slurry was higher than 4.5, the desulfurization efficiency was stable about 90%. The SO2 removal efficiency appeared to increase along with the increasing of absorbent cycle-index. The efficiency of the second circulation was improved 3.5% compared to the first circulation. After an operating duration of 40 minutes, the leaching rate of vanadium pentoxide was about 20%, and reached 60% when the by-products were leached with 5% dilute sulfuric acid for 10 hours. The by-product from this process not only could be used to produce vanadium pentoxide which is a valuable industrial product, but also could significantly overcome the pollution problem existing in the traditional refining process of vanadium pentoxide when navajoite ore is used as the feed material. This FGD process using roasted navajoite slurry as absorbent is environmental sound and cost-effective, and shows the potential for application in the field of flue gas desulfurization as well as hydrometallurgy. PMID:20527168

  10. 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.

  11. 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

  12. Spectroscopic and biocatalytic properties of a chlorophyll-containing extract in silica gel

    NASA Astrophysics Data System (ADS)

    Lipke, Agnieszka; Trytek, Mariusz; Fiedurek, Jan; Majdan, Marek; Janik, Ewa

    2013-11-01

    UV-Vis absorption and fluorescence spectra of chlorophyll a (in the form of spinach extract) in acetone solution and in silica gel showed a predominance of pigment dimers in its overall concentration and an evident transformation of chlorophyll a to pheophytin with time. The dimerization constant of chlorophyll a in acetone was log Kdim = 2.14, whereas the constants for chlorophyll a and pheophytin a in alcogel were log Kdim = 4.70 and log Kdim = 5.22, respectively. Biocatalytic experiments indicated the possibility of using the pigment embedded in silica gel, i.e. mainly its dimeric form, for biotransformation of α-pinene to pinocarveyl hydroperoxide, trans-pinocarveol, pinocarvone and myrtenal. The advantage of a heterogeneous biocatalytic system (composed of a solvent and silica gel) over a homogeneous system (single phase of chloroform) is the possibility of reusing the biocatalyst with about 10% preservation of its activity.

  13. Uniform lab-scale biocatalytic nanoporous latex coatings for reactive microorganisms.

    PubMed

    Gosse, Jimmy L; Flickinger, Michael C

    2011-01-01

    This chapter describes a method for generating uniform lab-scale biocatalytic nanoporous latex coatings. Nearly everything we come into contact with on a daily basis has been coated with some polymer material. High-speed waterborne polymer coating and ink-jet printing techniques are mature technologies. Methods for immobilizing microorganisms in lab-scale waterborne latex biocatalytic coatings draw on existing coating technologies for generating precision industrial paint and paper coatings and would therefore be amenable to scale up in future applications. An inherent problem for many lab-scale techniques is coating uniformity. The method described here has been developed to dramatically increase the uniformity of multiple individual small surface area coatings derived from a single coating template by minimizing edge effects due to emulsion drying adjacent to the edge of the mask. PMID:21553194

  14. 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.

  15. Biocatalytic approaches to a key building block for the anti-thrombotic agent ticagrelor.

    PubMed

    Hugentobler, Katharina G; Sharif, Humera; Rasparini, Marcello; Heath, Rachel S; Turner, Nicholas J

    2016-09-14

    three complementary biocatalytic routes were examined for the synthesis of the cyclopropyl amine (1R,2S)-2, which is a key building block for the anti-thrombotic agent ticagrelor 1. By employing either a ketoreductase, amidase or lipase biocatalyst, the key building blocks for synthesis of the amine 2 were obtained in 99.9, 92.5 and 46.3 ee, respectively. PMID:27470519

  16. Biocatalytic Synthesis of Chiral Alcohols and Amino Acids for Development of Pharmaceuticals

    PubMed Central

    Patel, Ramesh N.

    2013-01-01

    Chirality is a key factor in the safety and efficacy of many drug products and thus the production of single enantiomers of drug intermediates and drugs has become increasingly important in the pharmaceutical industry. There has been an increasing awareness of the enormous potential of microorganisms and enzymes derived there from for the transformation of synthetic chemicals with high chemo-, regio- and enatioselectivities. In this article, biocatalytic processes are described for the synthesis of chiral alcohols and unntural aminoacids for pharmaceuticals. PMID:24970190

  17. Optimizing the biocatalytic productivity of an engineered sialidase from Trypanosoma rangeli for 3'-sialyllactose production.

    PubMed

    Zeuner, Birgitte; Luo, Jianquan; Nyffenegger, Christian; Aumala, Ville; Mikkelsen, Jørn Dalgaard; Meyer, Anne S

    2014-02-01

    An engineered sialidase, Tr6, from Trypanosoma rangeli was used for biosynthetic production of 3'-sialyllactose, a human milk oligosaccharide case compound, from casein glycomacropeptide (CGMP) and lactose, components abundantly present in industrial dairy side streams. Four different enzyme re-use methods were compared to optimize the biocatalytic productivity, i.e. 3'-sialyllactose formation per amount of Tr6 employed: (i) His-tag immobilization on magnetic Cu²⁺-iminodiacetic acid-functionalized nanoparticles (MNPs), (ii) membrane immobilization, (iii) calcium alginate encapsulation of cross-linked Tr6, and (iv) Tr6 catalysis in a membrane reactor. Tr6 immobilized on MNPs gave a biocatalytic productivity of 84 mg 3'-sialyllactose/mg Tr6 after seven consecutive reaction runs. Calcium-alginate and membrane immobilization were inefficient. Using free Tr6 in a 10 kDa membrane reactor produced a 9-fold biocatalytic productivity increase compared to using free Tr6 in a batch reactor giving 306 mg 3'-sialyllactose/mg Tr6 after seven consecutive reaction runs. The 3'-sialyllactose yield on α-2,3-bound sialic acid in CGMP was 74%. Using circular dichroism, a temperature denaturation midpoint of Tr6, Tm, of 57.2 °C was determined. The thermal stability of free Tr6 was similarly high and the Tr6 was stable at the reaction temperature (25 °C) for at least 24 h. PMID:24411449

  18. Catalytic seawater flue gas desulfurization model.

    PubMed

    Vidal Barrero, F; Ollero, P; Villanueva Perales, A L; Gómez-Barea, A

    2009-12-15

    A model of a seawater flue gas desulfurization process (SFGD) where oxidation of the absorbed SO(2) is catalyzed by activated carbon is presented. The modeled SFGD process is comprised of two main units, an absorption packed scrubber, where SO(2) absorption takes place, and an oxidation basin, where the absorbed SO(2) is catalytically oxidized to sulfate, a natural component of seawater. The model takes into account the complex physical-chemical features of the process, combining mass-transfer, kinetics and equilibrium equations, and considering the electrolyte nature of the liquid phase. The model was validated with data from a SFGD pilot plant and a sensitivity analysis was performed, showing its predictive capability. The model is a useful tool for designing industrial desulfurization units with seawater. PMID:20000534

  19. Offshore desulfurization unit permits gas lift operations

    SciTech Connect

    Cabes, A.; Elgue, J.; Tournier-Lasserve, J. )

    1992-01-13

    This paper reports on the installation of a desulfurization unit for the Tchibouela oil field, offshore Congo, which allowed produced low-pressure associated gas containing CO{sub 2} to be kept for gas lift operations while, for safety reasons, the large volume of H{sub 2}S at low pressure was removed prior to compression. Since October 1989, the world's first offshore amine sweetening unit has worked satisfactorily and continues to prove that it is an attractive production alternative. For desulfurization, a selective methyldiethanolamine (MDEA) process, developed by Elf Aquitaine, was chosen because it was the only process that met the required specifications at a low pressure of 3.5 bar (51 psi).

  20. 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.

  1. Zirconia-silica based mesoporous desulfurization adsorbents

    NASA Astrophysics Data System (ADS)

    Palomino, Jessica M.; Tran, Dat T.; Kareh, Ana R.; Miller, Christopher A.; Gardner, Joshua M. V.; Dong, Hong; Oliver, Scott R. J.

    2015-03-01

    We report a series of mesoporous silicate sorbent materials templated by long-chain primary alkylamines that display record level of desulfurization of the jet fuel JP-8. Pure silica frameworks and those with a Si:Zr synthesis molar ratio ranging from 44:1 to 11:1 were investigated. The optimum sorbent was identified as dodecylamine-templated silica-zirconia synthesized from a gel with Si:Zr molar ratio of 15:1. With an optimized silver loading of 11 wt.%, a saturation adsorption capacity of 39.4 mgS g-1 and a silver efficiency of 1.21 molS mol Ag-1 were observed for JP-8. This sorbent displayed exceptional regenerability, maintaining 86% of its initial capacity in model fuel after solvent regeneration with diethyl ether. Low-cost, portable and reusable sorbents for the desulfurization of JP-8 jet fuel are needed to make solid oxide fuel cells (SOFCs) a reality for military power needs. SOFCs require ultra-low sulfur content fuel, which traditional desulfurization methods cannot achieve.

  2. Reclamation of abandoned surface coal mined land using flue gas desulfurization products

    SciTech Connect

    Chen, L.; Kost, D.; Dick, W.A.

    2009-07-01

    Details are given of a field-scale research project where the Fleming site, in Ohio, of highly degraded and acid-forming abandoned surface coal-mined land, was reclaimed using a dry flue gas desulfurization product from an atmospheric fluidized bed combustion burner at a General Motors plant Pontiac, MI, which burned eastern Ohio coal and used dolomitic limestone for desulfurization. Plots were seeded with a mixture of grasses, wheat and clover, in 1994 and soil and water samples were analysed in 1995 and in 2009. It was found that FGD-treated plots promoted good regenerative growth, similar to that in plots using more concentrated re-soil material. The FGD treatment also greatly improved overall water quality. 3 figs., 4 tabs.

  3. Characterization and fixed-bed testing of a nickel-based hot gas desulfurization sorbent

    SciTech Connect

    Gasper-Galvin, L.D.; Swisher, J.H.; Hammerbeck, K.

    1994-10-01

    The objective of this project was to (1) extend a preliminary investigation completed earlier on dispersed nickel sorbents by developing new processing methods, characterizing sorbent materials more extensively, and evaluating the materials in fixed bed reactor tests, and (2) to determine the feasibility of using dispersed nickel sorbents with reductive regeneration for hot gas desulfurization. One of the properties of nickel that is somewhat unique is that it forms a liquid sulfide at sufficiently high temperatures with high sulfur potentials or H{sub 2}S levels. A eutectic exists in the Ni-S phase diagram at 637 C and a composition of 33.4 wt% or 21.5 wt% S. Under controlled conditions, the formation of a liquid phase can be used to advantage in hot gas desulfurization. Sorbent preparation, the experimental unit, and experimental procedure are described. Results from the sorbent, 24Ni-7Cu-Al{sub 2}O{sub 3}, are given.

  4. Liquefaction and desulfurization of coal using synthesis gas

    DOEpatents

    Fu, Yuan C.

    1977-03-08

    A process for desulfurizing and liquefying coal by heating said coal at a temperature of 375.degree.-475.degree. C in the presence of a slurry liquid, hydrogen, carbon monoxide, steam, and a catalyst comprising a desulfurization catalyst and an alkali metal salt.

  5. HIGH-TEMPERATURE DESULFURIZATION OF LOW-BTU-GAS

    EPA Science Inventory

    The report describes and gives results of economic studies of a process for desulfurizing low-Btu fuel gas. The gas is first desulfurized at high temperature in a fluidized bed of half-calcined dolomite. It is then cooled to 700 C and passed through high-pressure-drop cyclones to...

  6. Flue gas desulfurization gypsum agricultural network alabama (cotton)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flue gas desulfurization gypsum (FGDG) is an excellent source of gypsum (CaSO4•2H2O) that can be beneficially used in agriculture. Research was conducted as part of the Flue Gas Desulfurization Gypsum Agricultural Network program sponsored by the Electric Power Research Institute in collaboration wi...

  7. FLUE GAS DESULFURIZATION PILOT STUDY. PHASE II. APPLICABILITY STUDY

    EPA Science Inventory

    The North Atlantic Treaty Organization Committee on the Challenges of Modern Society (NATO-CCMS) Flue Gas Desulfurization (FGD) Study Group prepared status reports on 12 FGD processes. Results of this work are summarized in NATO Report No. 95 titled 'Flue Gas Desulfurization Pilo...

  8. 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.

  9. Separation of Mercury from Flue Gas Desulfurization Scrubber Produced Gypsum

    SciTech Connect

    Hensman, Carl, E., P.h.D; Baker, Trevor

    2008-06-16

    Frontier Geosciences (Frontier; FGS) proposed for DOE Grant No. DE-FG02-07ER84669 that mercury control could be achieved in a wet scrubber by the addition of an amendment to the wet-FGD scrubber. To demonstrate this, a bench-scale scrubber and synthetic flue-gas supply was designed to simulate the limestone fed, wet-desulfurization units utilized by coal-fired power plants. Frontier maintains that the mercury released from these utilities can be controlled and reduced by modifying the existing equipment at installations where wet flue-gas desulfurization (FGD) systems are employed. A key element of the proposal was FGS-PWN, a liquid-based mercury chelating agent, which can be employed as the amendment for removal of all mercury species which enter the wet-FGD scrubber. However, the equipment design presented in the proposal was inadequate to demonstrate these functions and no significant progress was made to substantiate these claims. As a result, funding for a Phase II continuation of this work will not be pursued. The key to implementing the technology as described in the proposal and report appears to be a high liquid-to-gas ratio (L/G) between the flue-gas and the scrubber liquor, a requirement not currently implemented in existing wet-FGD designs. It may be that this constraint can be reduced through parametric studies, but that was not apparent in this work. Unfortunately, the bench-scale system constructed for this project did not function as intended and the funds and time requested were exhausted before the separation studies could occur.

  10. A NOVEL APPROACH TO CATALYTIC DESULFURIZATION OF COAL

    SciTech Connect

    John G. Verkade

    1997-08-31

    Remarkably mild conditions have been discovered for quantitative sulfur removal from dibenzothiophene and other organosulfur systems using relatively cheap elemental sodium. The project objectives are: (1) Optimize the coal desulfurization reaction with respect to time, temperature, coal type and the R groups (including R = H), and also on extraction, impregnation and sonication conditions; (2) Optimize the conditions for the HDS reaction (which allows the PR{sub 3} to function as an HDS catalyst for coal) with respect to R group, temperature, pressure, H{sub 2} gas flow rate and inert solvent presence; (3) Determine the product(s) and the pathway of the novel redox reaction that appears to quantitatively remove sulfur from dibenzothiophene (DBT) when R = Bu when FeCl{sub 3} is used as a catalyst; (4) Impregnate sulfur-laden coals with Fe{sup 3+} to ascertain if the PR{sub 3} desulfurization rate increases; (5) Determine the nature of the presently unextractable phosphorus compounds formed in solid coals by PR{sub 3}; (6) Explore the efficacy of PR{sub 3}/Fe{sup 3+} in removing sulfur from petroleum feedstocks, heavy ends (whether solid or liquid), coal tar and discarded tire rubber; (7) Explore the possibility of using water-soluble PR{sub 3} compounds and Fe{sup 3+} to remove sulfur from petroleum feedstocks and heavy ends in order to remove the SPR{sub 3} (and Fe{sup 3+} catalyst) by water extraction (for subsequent HDS of the SPR{sub 3}); and (8) Explore the possibility of using solid-supported PR{sub 3} compounds (plus Fe{sup 3+} catalyst) to remove sulfur from petroleum feedstocks and heavy ends in order to keep the oil and the SPR{sub 3} (formed in the reaction) in easily separable phases.

  11. Enviropower hot gas desulfurization pilot

    SciTech Connect

    Ghazanfari, R.; Feher, G.; Konttinen, J.; Ghazanfari, R.; Lehtovaara, A.; Mojtahedi, W.

    1994-11-01

    The objectives of the project are to develop and demonstrate (1) hydrogen sulfide removal using regenerable zinc titanate sorbent in pressurized fluidized bed reactors, (2) recovery of the elemental sulfur from the tail-gas of the sorbent regenerator and (3) hot gas particulate removal system using ceramic candle filters. Results are presented on pilot plant design and testing and modeling efforts.

  12. Bench-scale development of mild gasification char desulfurization; [Quarterly] report, September 1--November 30, 1993

    SciTech Connect

    Knight, R.A.

    1994-03-01

    This goal of this project is to scale up a process, developed under a previous ICCI grant, for desulfurization of mild gasification char by treatment with hydrogen-rich process-derived fuel gas at 650{degree}--760{degree}C and 7-15 atm. The char can be converted into a low-sulfur metallurgical form coke. In the prior study, IBC-105 coal with 4.0 wt % sulfur was converted to chars with less than 1.0 wt % sulfur in a laboratory-scale batch reactor. The susceptibility of the char to desulfurization was correlated with physicochemical char properties and mild gasification conditions. Acid pretreatment of the coal prior to mild gasification was also shown to significantly enhance subsequent sulfur removal. In this study, IGT is conducting continuous bench-scale tests in a 1-lb/h fluidized-bed reactor to determine the preferred process conditions and obtain steady-state data necessary for process design and scale-up. The desulfurized chars are to be used to produce low-sulfur form coke, which will be evaluated for density, reactivity, and strength properties relevant to utilization in blast furnaces. During the first quarter, 180 lb (82 kg) of IBC-105 coal was obtained and subjected to crushing, and sizing to prepare 49 lb (22 kg) of material for test operation.

  13. 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.

  14. 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.

  15. 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.

  16. Enzymatic desulfurization of coal: Third quarterly report

    SciTech Connect

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

    1989-03-14

    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. In this quarter we obtained important results both with the development of our understanding of the enzyme reaction systems and also with the microbial work at Woods Hole. 12 figs., 11 tabs.

  17. Kinetics of the desulfurization of molten iron. Final report

    SciTech Connect

    Gaskell, D.R.

    1981-03-01

    Experimental work has involved the fabrication of impervious slip-cast CaO crucibles, measurement of the rate of desulfurization of liquid iron by solid CaO and measurement of the rate of desulfurization of liquid iron by CaO-saturated liquid FeO. Above 0.087 < wt % S < 0.67, the activity of FeS is high enough to form a liquid phase in the system CaO-Fe-S. With lower sulfur levels, CaO does not cause any desulfurization of the liquid iron. When CaO-saturated liquid FeO is brought into contact with a liquid Fe-S alloy a rapid initial rate of desulfurization occurs due to surface tension-induced local convection at the slag-metal interface. After this initial period, the rate of desulfurization is determined by diffusion of sulfur in the metal. No change occurs in the oxygen content of the metal during desulfurization and hence the half cell reactions occurring in the electrochemical transfer process are (Fe) ..-->.. (Fe/sup 2 +/) + 2e/sup -/ and (S) + 2e/sup -/ ..-->.. (S/sup 2 -/). Addition of CaF/sub 2/ to the CaO-saturated slag has no effect on the desulfurization.

  18. 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.

  19. 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. PMID:21476358

  20. NID dry desulfurization system -- An update

    SciTech Connect

    Ahman, S.; Bengtsson, S.

    1998-07-01

    The development of ABB's low cost flue gas desulfurization (FGD) system has been reported in various papers during 1997. The system combines low cost and simple operation with very good performance and is targeted especially for the emerging markets in Asia and East Europe. This method is capable of achieving 90+% SO{sub 2} removal, irrespective of sulphur content in the fuel. The system is further easy to retrofit at existing sites; it has a minimum space requirement. An important feature of the dry FGD technology, sometimes not highlighted enough, is the fact that particulate collection of fly ash is facilitated by the FGD system at no extra capital charge. The flue gas temperature after a DFGD system also often allows the flue gas to be passed on to an existing stack without reheat. ``NID'' is an acronym for ``Novel Integrated Desulfurization'', indicative of the innovative nature of this FGD technology enabled by the integration of several subfunctionalities into one unit. The first two commercial plants were installed by the Polish power company Elektrownia Laziska. These full scale units were commissioned during 1996. A third unit at a diesel power station in Finland is at the time of writing in the commissioning stage.

  1. Scale-Up of Advanced Hot-Gas desulfurization Sorbents.

    SciTech Connect

    Jothimurugesan, K.; Gangwal, S.K.

    1997-10-02

    The overall objective of this project is to develop regenerable sorbents for hot gas desulfurization in IGCC systems. The specific objective of the project is to develop durable advanced sorbents that demonstrate a strong resistance to attrition and chemical deactivation, and high activity at temperatures as low as 343 {degrees}C (650{degrees}F). A number of formulations will be prepared and screened in a one-half inch fixed bed reactor at high pressure (1 to 20 atm) and high temperatures using simulated coal-derived fuel- gases. Screening criteria will include chemical reactivity, stability, and regenerability over the temperature range of 343{degrees}C to 650{degrees}C. After initial screening, at least 3 promising formulations will be tested for 25-30 cycles of absorption and regeneration. One of the superior formulations with the best cyclic performance will be selected for investigating scale up parameters. The scaled-up formulation will be tested for long term durability and chemical reactivity.

  2. Scale-Up of Advanced Hot-Gas Desulfurization Sorbents

    SciTech Connect

    Jothimurugesan, K.; Gangwal, S.K.

    1997-04-21

    The overall objective of this project is to develop regenerable sorbents for hot gas desulfurization in IGCC systems. The specific objective of the project is to develop durable advanced sorbents that demonstrate a strong resistance to attrition and chemical deactivation, and high activity at temperatures as low as 343{degrees}C (650{degrees}F). A number of formulations will be prepared and screened in a 1/2-inch fixed bed reactor at high pressure (1 to 20 atm) and high temperatures using simulated coal-derived fuel-gases. Screening criteria will include, chemical reactivity, stability, and regenerability over the temperature range of 343{degrees}C to 650{degrees}C. After initial screening, at least 3 promising formulations will be tested for 25-30 cycles of absorption and regeneration. One of the superior formulations with the best cyclic performance will be selected for investigating scale up parameters. The scaled-up formulation will be tested for long term durability and chemical reactivity.

  3. Recent advances on halohydrin dehalogenases-from enzyme identification to novel biocatalytic applications.

    PubMed

    Schallmey, Anett; Schallmey, Marcus

    2016-09-01

    Halohydrin dehalogenases are industrially relevant enzymes that catalyze the reversible dehalogenation of vicinal haloalcohols with formation of the corresponding epoxides. In the reverse reaction, also other negatively charged nucleophiles such as azide, cyanide, or nitrite are accepted besides halides to open the epoxide ring. Thus, novel C-N, C-C, or C-O bonds can be formed by halohydrin dehalogenases, which makes them attractive biocatalysts for the production of various β-substituted alcohols. Despite the fact that only five individual halohydrin dehalogenase enzyme sequences have been known until recently enabling their heterologous production, a large number of different biocatalytic applications have been reported using these enzymes. The recent characterization of specific sequence motifs has facilitated the identification of novel halohydrin dehalogenase sequences available in public databases and has largely increased the number of recombinantly available enzymes. These will help to extend the biocatalytic repertoire of this enzyme family and to foster novel biotechnological applications and developments in the future. This review gives a general overview on the halohydrin dehalogenase enzyme family and their biochemical properties and further focuses on recent developments in halohydrin dehalogenase biocatalysis and protein engineering. PMID:27502414

  4. Biocatalytic potential of laccase-like multicopper oxidases from Aspergillus niger

    PubMed Central

    2012-01-01

    Background Laccase-like multicopper oxidases have been reported in several Aspergillus species but they remain uncharacterized. The biocatalytic potential of the Aspergillus niger fungal pigment multicopper oxidases McoA and McoB and ascomycete laccase McoG was investigated. Results The laccase-like multicopper oxidases McoA, McoB and McoG from the commonly used cell factory Aspergillus niger were homologously expressed, purified and analyzed for their biocatalytic potential. All three recombinant enzymes were monomers with apparent molecular masses ranging from 80 to 110 kDa. McoA and McoG resulted to be blue, whereas McoB was yellow. The newly obtained oxidases displayed strongly different activities towards aromatic compounds and synthetic dyes. McoB exhibited high catalytic efficiency with N,N-dimethyl-p-phenylenediamine (DMPPDA) and 2,2-azino-di(3-ethylbenzthiazoline) sulfonic acid (ABTS), and appeared to be a promising biocatalyst. Besides oxidizing a variety of phenolic compounds, McoB catalyzed successfully the decolorization and detoxification of the widely used textile dye malachite green. Conclusions The A. niger McoA, McoB, and McoG enzymes showed clearly different catalytic properties. Yellow McoB showed broad substrate specificity, catalyzing the oxidation of several phenolic compounds commonly present in different industrial effluents. It also harbored high decolorization and detoxification activity with the synthetic dye malachite green, showing to have an interesting potential as a new industrial biocatalyst. PMID:23270588

  5. Thermostabilization of desulfurization enzymes from Rhodococcos sp. IGTS8. Final technical report

    SciTech Connect

    John J. Kilbane II

    2000-12-15

    The objective of this project was to develop thermophilic cultures capable of expressing the desulfurization (dsz) operon of Rhodococcus sp. IGTS8. The approaches taken in this project included the development of plasmid and integrative expression vectors that function well in Thermus thermophilus, the cloning of Rhodococcus dsz genes in Thermus expression vectors, and the isolation of bacterial cultures that express the dsz operon at thermophilic temperatures. This project has resulted in the development of plasmid and integrative expression vectors for use in T. thermophilus. The dsz genes have been expressed at moderately thermophilic temperatures (52 C) in Mycobacterium phlei and at temperatures as high as 72 C in T. thermophilus. The tools and methods developed in this project will be generally useful for the expression of heterologous genes in Thermus. Key developments in the project have been the isolation of a Mycobacterium phlei culture capable of expressing the desulfurization operon at 52 C, development of plasmid and integrative expression vectors for Thermus thermophilus, and the development of a host-vector system based on the malate dehydrogenase gene that allows plasmids to be stably maintained in T. thermophilus and provides a convenient reporter gene for the accurate quantification of gene expression. Publications have been prepared regarding each of these topics; these preprints are included.

  6. Shawnee flue gas desulfurization computer model users manual

    SciTech Connect

    Sudhoff, F.A.; Torstrick, R.L.

    1985-03-01

    In conjunction with the US Enviromental Protection Agency sponsored Shawnee test program, Bechtel National, Inc., and the Tennessee Valley Authority jointly developed a computer model capable of projecting preliminary design and economics for lime- and limestone-scrubbing flue gas desulfurization systems. The model is capable of projecting relative economics for spray tower, turbulent contact absorber, and venturi-spray tower scrubbing options. It may be used to project the effect on system design and economics of variations in required SO/sub 2/ removal, scrubber operating parameters (gas velocity, liquid-to-gas (L/G) ration, alkali stoichiometry, liquor hold time in slurry recirculation tanks), reheat temperature, and scrubber bypass. It may also be used to evaluate alternative waste disposal methods or additives (MgO or adipic acid) on costs for the selected process. Although the model is not intended to project the economics of an individual system to a high degree of accuracy, it allows prospective users to quickly project comparative design and costs for limestone and lime case variations on a common design and cost basis. The users manual provides a general descripton of the Shawnee FGD computer model and detailed instructions for its use. It describes and explains the user-supplied input data which are required such as boiler size, coal characteristics, and SO/sub 2/ removal requirments. Output includes a material balance, equipment list, and detailed capital investment and annual revenue requirements. The users manual provides information concerning the use of the overall model as well as sample runs to serve as a guide to prospective users in identifying applications. The FORTRAN-based model is maintained by TVA, from whom copies or individual runs are available. 25 refs., 3 figs., 36 tabs.

  7. HIGH EFFICIENCY DESULFURIZATION OF SYNTHESIS GAS

    SciTech Connect

    Kwang-Bok Yi; Elizabeth J. Podlaha; Douglas P. Harrison

    2003-11-01

    Mixed metal oxides containing CeO{sub 2} and ZrO{sub 2} are being studied as high temperature desulfurization sorbents capable of achieving the DOE Vision 21 target of 1 ppmv or less H{sub 2}S. The research is justified by recent results in this laboratory that showed that reduced CeO{sub 2}, designated CeOn (1.5 < n < 2.0), is capable of achieving the 1 ppmv target in highly reducing gas atmospheres. The addition of ZrO{sub 2} has improved the performance of oxidation catalysts and three-way automotive catalysts containing CeO{sub 2}, and should have similar beneficial effects on CeO{sub 2} desulfurization sorbents. An electrochemical method for synthesizing CeO{sub 2}-ZrO{sub 2} was developed and the products were characterized by XRD and TEM during year 01. Nanocrystalline particles having a diameter of about 5 nm and containing from approximately 10 mol% to 80 mol% ZrO{sub 2} were prepared. XRD analysis showed the product to be a solid solution at low ZrO{sub 2} contents with a separate ZrO{sub 2} phase emerging at higher ZrO{sub 2} levels. Unfortunately, the quantity of CeO{sub 2}-ZrO{sub 2} that could be prepared electrochemically was too small to permit full desulfurization testing. Also during year 01 a laboratory-scale fixed-bed reactor was constructed for desulfurization testing. All components of the reactor and analytical systems that may be exposed to low concentrations of H{sub 2}S are constructed of quartz, Teflon, or silcosteel. Reactor product gas composition as a function of time is determined using a Varian 3800 gas chromatograph equipped with a pulsed flame photometric detector (PFPD) for measuring low H{sub 2}S concentrations (<{approx}10 ppmv) and a thermal conductivity detector (TCD) for higher concentrations of H{sub 2}S. Larger quantities of CeO{sub 2}-ZrO{sub 2} mixtures from other sources, including mixtures prepared in this laboratory using a coprecipitation procedure, have been obtained. Much of the work during year 02 consisted of

  8. HIGH EFFICIENCY DESULFURIZATION OF SYNTHESIS GAS

    SciTech Connect

    Kwang-Bok Yi; Elizabeth J. Podlaha; Douglas P. Harrison

    2002-11-01

    Mixed metal oxides containing CeO{sub 2} and ZrO{sub 2} are being studied as high temperature desulfurization sorbents capable of achieving the DOE Vision 21 target of 1 ppmv or less H{sub 2}S. The research is justified by recent results in this laboratory that showed that reduced CeO{sub 2}, designated CeO{sub n} (1.5 < n < 2.0), is capable of achieving the 1 ppmv target in highly reducing gas atmospheres. The addition of ZrO{sub 2} has improved the performance of oxidation catalysts and three-way automotive catalysts containing CeO{sub 2}, and should have similar beneficial effects on CeO{sub 2} desulfurization sorbents. An electrochemical method for synthesizing CeO{sub 2}-ZrO{sub 2} was developed and the products were characterized by XRD and TEM during year 01. Nanocrystalline particles having a diameter of about 5 nm and containing from approximately 10 mol% to 80 mol% ZrO{sub 2} were prepared. XRD showed the product to be a solid solution at low ZrO{sub 2} contents with a separate ZrO{sub 2} phase emerging at higher ZrO{sub 2} levels. Unfortunately, the quantity of CeO{sub 2}-ZrO{sub 2} that could be prepared electrochemically was too small to permit full testing in our desulfurization reactor. Also during year 01 a laboratory-scale fixed-bed reactor was constructed for desulfurization testing. All components of the reactor and analytical systems that may be exposed to low concentrations of H{sub 2}S are constructed of quartz, Teflon, or silcosteel. Reactor product gas composition as a function of time is determined using a Varian 3800 gas chromatograph equipped with a pulsed flame photometric detector (PFPD) for measuring low H{sub 2}S concentrations ({approx}< 10 ppmv) and a thermal conductivity detector (TCD) for higher concentrations of H{sub 2}S. Larger quantities of CeO{sub 2}-ZrO{sub 2} mixtures from other sources, including mixtures prepared in this laboratory using a coprecipitation procedure, have been obtained. Characterization and desulfurization

  9. HIGH EFFICIENCY DESULFURIZATION OF SYNTHESIS GAS

    SciTech Connect

    Kwang-Bok Yi; Anirban Mukherjee; Elizabeth J. Podlaha; Douglas P. Harrison

    2004-03-01

    Mixed metal oxides containing ceria and zirconia have been studied as high temperature desulfurization sorbents with the objective of achieving the DOE Vision 21 target of 1 ppmv or less H{sub 2}S in the product gas. The research was justified by recent results in this laboratory that showed that reduced CeO{sub 2}, designated CeOn (1.5 < n < 2.0), is capable of achieving the 1 ppmv target in highly reducing gas atmospheres. The addition of ZrO{sub 2} has improved the performance of oxidation catalysts and three-way automotive catalysts containing CeO{sub 2}, and was postulated to have similar beneficial effects on CeO{sub 2} desulfurization sorbents. An electrochemical method for synthesizing CeO{sub 2}-ZrO{sub 2} mixtures was developed and the products were characterized by XRD and TEM during year 01. Nanocrystalline particles having a diameter of about 5 nm and containing from approximately 10 mol% to 80 mol% ZrO{sub 2} were prepared. XRD analysis showed the product to be a solid solution at low ZrO{sub 2} contents with a separate ZrO{sub 2} phase emerging at higher ZrO{sub 2} levels. Unfortunately, the quantity of CeO{sub 2}-ZrO{sub 2} that could be prepared electrochemically was too small to permit desulfurization testing. Also during year 01 a laboratory-scale fixed-bed reactor was constructed for desulfurization testing. All components of the reactor and analytical systems that were exposed to low concentrations of H{sub 2}S were constructed of quartz, Teflon, or silcosteel. Reactor product gas composition as a function of time was determined using a Varian 3800 gas chromatograph equipped with a pulsed flame photometric detector (PFPD) for measuring low H{sub 2}S concentrations from approximately 0.1 to 10 ppmv, and a thermal conductivity detector (TCD) for higher concentrations of H{sub 2}S. Larger quantities of CeO{sub 2}-ZrO{sub 2} mixtures from other sources, including mixtures prepared in this laboratory using a coprecipitation procedure, were obtained

  10. 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.

  11. HIGH EFFICIENCY DESULFURIZATION OF SYNTHESIS GAS

    SciTech Connect

    Anirban Mukherjee; Kwang-Bok Yi; Elizabeth J. Podlaha; Douglas P. Harrison

    2001-11-01

    Mixed metal oxides containing CeO{sub 2} and ZrO{sub 2} are being studied as high temperature desulfurization sorbents capable of achieving the DOE Vision 21 target of 1 ppmv of less H{sub 2}S. The research is justified by recent results in this laboratory that showed that reduced CeO{sub 2}, designated CeO{sub n} (1.5 < n < 2.0), is capable of achieving the 1 ppmv target in highly reducing gas atmospheres. The addition of ZrO{sub 2} has improved the performance of oxidation catalysts and three-way automotive catalysts containing CeO{sub 2}, and should have similar beneficial effects on CeO{sub 2} desulfurization sorbents. An electrochemical method for synthesizing CeO{sub 2}-ZrO{sub 2} has been developed and the products have been characterized by XRD and TEM during year 01. Nanocrystalline particles having a diameter of about 5 nm and containing from approximately 10 mol% to 80 mol% ZrO{sub 2} have been prepared. XRD showed the product to be a solid solution at low ZrO{sub 2} contents with a separate ZrO{sub 2} phase emerging at higher ZrO{sub 2} levels. Phase separation did not occur when the solid solutions were heat treated at 700 C. A flow reactor system constructed of quartz and teflon has been constructed, and a gas chromatograph equipped with a pulsed flame photometric detector (PFPD) suitable for measuring sub-ppmv levels of H{sub 2}S has been purchased with LSU matching funds. Preliminary desulfurization tests using commercial CeO{sub 2} and CeO{sub 2}-ZrO{sub 2} in highly reducing gas compositions has confirmed that CeO{sub 2}-ZrO{sub 2} is more effective than CeO{sub 2} in removing H{sub 2}S. At 700 C the product H{sub 2}S concentration using CeO{sub 2}-ZrO{sub 2} sorbent was near the 0.1 ppmv PFPD detection limit during the prebreakthrough period.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Genetic approach to microbial coal desulfurization

    SciTech Connect

    Clark, D.P. . Dept. of Microbiology)

    1990-07-01

    Naturally occurring sulfur bacteria such as Thiobacillus and Sulfolobus can remove inorganic sulfur from coal. We hope to contribute to the development of genetically engineered bacteria which can remove the organic sulfur effectively. A process which used an appropriate mixture of bacteria to remove both types of sulfur from coal should be inexpensive and produce harmless waste products. We are cloning genes from an Escherichia coli mutant with the ability to oxidize thiophene derivatives in order to enhance this ability. We are also cloning plasmid-borne genes from wild dibenzothiophene degrading strains. By putting together the best genes from various organisms we hope to construct an efficient desulfurizing bacterium. 25 refs., 3 figs., 3 tabs.

  18. 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.

  19. 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

  20. Desulfurization sorbent development at the Morgantown Energy Technology Center

    SciTech Connect

    Siriwardane, R.V.; Grimm, U.; Poston, J.A.; Monaco, S.J.

    1994-10-01

    The overall objective of this project is to develop regenerable sorbents for hot gas desulfurization in IGCC systems. The major criteria for the development of novel sorbents included reasonable chemical reactivity and physical durability during repeated sulfidation and regeneration cycles. Various formulations of zinc ferrite and zinc titanate in the form of extrudates and spherical pellets have been studied at the Morgantown Energy Technology Center (METC) for removal of sulfurous gases from coal gasification gas streams. Problems of decrepitation and spalling have occurred after sulfidation and regeneration of these sorbents. Z-Sorb, a proprietary sorbent developed at Phillips Petroleum Company, showed good physical durability during testing at METC, but there was a continuous decrease in reactivity during multiple cycle tests due to steam regeneration. A series of novel sorbents containing zinc oxide have been developed at METC to address these problems. These METC-developed sorbents showed superior performance during a 20-cycle, high-pressure, fixed-bed test with steam regeneration conducted at METC. Nine sorbents were prepared, but results are given for only three.

  1. Economic assessment of advanced flue gas desulfurization processes. Final report

    SciTech Connect

    Bierman, G. R.; May, E. H.; Mirabelli, R. E.; Pow, C. N.; Scardino, C.; Wan, E. I.

    1981-09-01

    This report presents the results of a project sponsored by the Morgantown Energy Technology Center (METC). The purpose of the study was to perform an economic and market assessment of advanced flue gas desulfurization (FGD) processes for application to coal-fired electric utility plants. The time period considered in the study is 1981 through 1990, and costs are reported in 1980 dollars. The task was divided into the following four subtasks: (1) determine the factors affecting FGD cost evaluations; (2) select FGD processes to be cost-analyzed; (3) define the future electric utility FGD system market; and (4) perform cost analyses for the selected FGD processes. The study was initiated in September 1979, and separate reports were prepared for the first two subtasks. The results of the latter two subtasks appear only in this final reprot, since the end-date of those subtasks coincided with the end-date of the overall task. The Subtask 1 report, Criteria and Methods for Performing FGD Cost Evaluations, was completed in October 1980. A slightly modified and condensed version of that report appears as appendix B to this report. The Subtask 2 report, FGD Candidate Process Selection, was completed in January 1981, and the principal outputs of that subtask appear in Appendices C and D to this report.

  2. 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.

  3. Enzymatic synthesis and modification of structured phospholipids: recent advances in enzyme preparation and biocatalytic processes.

    PubMed

    Hama, Shinji; Ogino, Chiaki; Kondo, Akihiko

    2015-10-01

    Phospholipids (PLs) containing specific polar head groups and fatty acids, artificially synthesized from a complex mixture of natural PLs, have considerable industrial applications. The biocatalytic approaches to synthesizing structured PLs are of great interest because the enzymes used show high selectivity and performance under mild conditions, leading to the generation of products that cannot easily be obtained by chemical catalysis. Although the limited supply of phospholipases (e.g., phospholipase D) has thus far been an obstacle to the widespread use of enzymatic processing, recent advances in enzyme preparation have opened up various applications for PL modification. In this review, attempts to increase the productivity and utility of microbial phospholipases and lipases are presented. We also summarize recent developments in enzyme-catalyzed modification of PLs, focusing particularly on the relevant reactions, bioreactor design, and novel proof-of-concept experiments. PMID:26245679

  4. Biocatalytic Synthesis of Acrylates in Supercritical Fluids: Tuning Enzyme Activity by Changing Pressure

    NASA Astrophysics Data System (ADS)

    Kamat, Sanjay V.; Iwaskewycz, Brian; Beckman, Eric J.; Russell, Alan J.

    1993-04-01

    Supercritical fluids are a unique class of non-aqueous media in which biocatalytic reactions can occur. The physical properties of supercritical fluids, which include gas-like diffusivities and liquid-like densities, can be predictably controlled with changing pressure. This paper describes how adjustment of pressure, with the subsequent predictable changes of the dielectric constant and Hildebrand solubility parameter for fluoroform, ethane, sulfur hexafluoride, and propane, can be used to manipulate the activity of lipase in the transesterification of methylmethacrylate with 2-ethyl-1-hexanol. Of particular interest is that the dielectric constant of supercritical fluoroform can be tuned from approximately 1 to 8, merely by increasing pressure from 850 to 4000 psi (from 5.9 to 28 MPa). The possibility now exists to predictably alter both the selectivity and the activity of a biocatalyst merely by changing pressure.

  5. Biocatalytic Characterization of Human FMO5: Unearthing Baeyer-Villiger Reactions in Humans.

    PubMed

    Fiorentini, Filippo; Geier, Martina; Binda, Claudia; Winkler, Margit; Faber, Kurt; Hall, Mélanie; Mattevi, Andrea

    2016-04-15

    Flavin-containing mono-oxygenases are known as potent drug-metabolizing enzymes, providing complementary functions to the well-investigated cytochrome P450 mono-oxygenases. While human FMO isoforms are typically involved in the oxidation of soft nucleophiles, the biocatalytic activity of human FMO5 (along its physiological role) has long remained unexplored. In this study, we demonstrate the atypical in vitro activity of human FMO5 as a Baeyer-Villiger mono-oxygenase on a broad range of substrates, revealing the first example to date of a human protein catalyzing such reactions. The isolated and purified protein was active on diverse carbonyl compounds, whereas soft nucleophiles were mostly non- or poorly reactive. The absence of the typical characteristic sequence motifs sets human FMO5 apart from all characterized Baeyer-Villiger mono-oxygenases so far. These findings open new perspectives in human oxidative metabolism. PMID:26771671

  6. Biocatalytic methanation of hydrogen and carbon dioxide in a fixed bed bioreactor.

    PubMed

    Alitalo, Anni; Niskanen, Marko; Aura, Erkki

    2015-11-01

    Biocatalytic methanation of H2 and CO2 was studied in a fixed bed reactor system consisting of two solid state bioreactors in series connected to a recirculation system. Bioreactors were packed with a mixture of vermiculite shales and granular perlite material as a support material. A maximal methane productivity of 6.35l/lreactord was achieved at a hydrogen feed rate of 25.2l/lreactord, while hydrogen conversion rate was 100%. However, stable operation of the reactor at this efficiency remains to be achieved. Very simple reactor design, constructed from low cost materials, and the idea of exploiting waste material as a robust source of nutrients for methanogens makes this study very interesting regarding the overall usability and suitability of the system as part of a decentralized energy system. PMID:26298404

  7. A biocatalytic approach towards synthesis of polymer CdS nanocomposites

    SciTech Connect

    Banerjee, S.; Premchandran, R.; Baumgartner, T.

    1996-10-01

    Copolymers of hydroxythiophenol and ethylphenol have been prepared using a biocatalytic route. Specifically, the method utilizes an oxidative enzyme, horseradish peroxidase, solubilized within the aqueous phase of a AOT/isooctane microemulsion. The monomers are oil soluble and are thus present in the organic phase. High conversions are obtained upto 1:1 molar ratio of the two monomers. The resulting polymers have the overall morphology of interconnected submicron spheres and are soluble in common organic solvents. Following their synthesis these copolymers have been derivatized by attaching Q-sized CdS particles. Though the copolymer itself is nonfluorescent, the CdS nanoclusters within it can be selectively excited and made to fluoresce. The fluorescent properties of the polymer CdS composite are distinctive from underivatized CdS or hydroxythiophenol monomer capped CdS.

  8. A process optimization for bio-catalytic production of substituted catechols (3-nitrocatechol and 3-methylcatechol

    PubMed Central

    2010-01-01

    Background Substituted catechols are important precursors for large-scale synthesis of pharmaceuticals and other industrial products. Most of the reported chemical synthesis methods are expensive and insufficient at industrial level. However, biological processes for production of substituted catechols could be highly selective and suitable for industrial purposes. Results We have optimized a process for bio-catalytic production of 3-substituted catechols viz. 3-nitrocatechol (3-NC) and 3-methylcatechol (3-MC) at pilot scale. Amongst the screened strains, two strains viz. Pseudomonas putida strain (F1) and recombinant Escherichia coli expression clone (pDTG602) harboring first two genes of toluene degradation pathway were found to accumulate 3-NC and 3-MC respectively. Various parameters such as amount of nutrients, pH, temperature, substrate concentration, aeration, inoculums size, culture volume, toxicity of substrate and product, down stream extraction, single step and two-step biotransformation were optimized at laboratory scale to obtain high yields of 3-substituted catechols. Subsequently, pilot scale studies were performed in 2.5 liter bioreactor. The rate of product accumulation at pilot scale significantly increased up to ~90-95% with time and high yields of 3-NC (10 mM) and 3-MC (12 mM) were obtained. Conclusion The biocatalytic production of 3-substituted catechols viz. 3-NC and 3-MC depend on some crucial parameters to obtain maximum yields of the product at pilot scale. The process optimized for production of 3-substituted catechols by using the organisms P. putida (F1) and recombinant E. coli expression clone (pDTG602) may be useful for industrial application. PMID:20587073

  9. 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

  10. ENHANCED CONTROL OF MERCURY BY WET FLUE GAS DESULFURIZATION SYSTEMS

    SciTech Connect

    G. Blythe; B. Marsh; S. Miller; C. Richardson; M. Richardson

    2001-06-01

    The U.S. Department of Energy and EPRI have co-funded this project to improve the control of mercury emissions from coal-fired power plants equipped with wet flue gas desulfurization (FGD) systems. The project investigated catalytic oxidation of vapor-phase elemental mercury to a form that is more effectively captured in wet FGD systems. If successfully developed, the process could be applicable to over 90,000 MW of utility generating capacity with existing FGD systems and to future FGD installations. Field tests have been conducted to determine whether candidate catalyst materials remain active towards mercury oxidation after extended flue gas exposure. Catalyst life will have a large impact on the cost effectiveness of this potential process. A mobile catalyst test unit has been used to test the activity of four different catalyst materials for a period of up to six months at each of three utility sites. Catalyst testing was completed at the first site, which fires Texas lignite, in December 1998 and at the second test site, which fires a Powder River Basin subbituminous coal in the fall of 1999. Testing at the third site, which fires a medium- to high-sulfur bituminous coal, began in June 2000 and was completed at the end of January 2001. This Topical Reports includes results from Site 3; results from Sites 1 and 2 were reported previously. At Site 3, catalysts were tested in two forms, including powders dispersed in sand bed reactors and in a commercially available form as a coated honeycomb structure. Field testing has been supported by laboratory tests to screen catalysts for activity at specific flue gas compositions, to investigate catalyst deactivation mechanisms and methods for regenerating spent catalysts. Laboratory results related to the Site 3 field effort are also included and discussed in this Topical Report.

  11. ENHANCED CONTROL OF MERCURY BY WET FLUE GAS DESULFURIZATION SYSTEMS

    SciTech Connect

    Unknown

    2001-06-01

    The U.S. Department of Energy and EPRI co-funded this project to improve the control of mercury emissions from coal-fired power plants equipped with wet flue gas desulfurization (FGD) systems. The project has investigated catalytic oxidation of vapor-phase elemental mercury to a form that is more effectively captured in wet FGD systems. If successfully developed, the process could be applicable to over 90,000 MW of utility generating capacity with existing FGD systems, and to future FGD installations. Field tests were conducted to determine whether candidate catalyst materials remain active towards mercury oxidation after extended flue gas exposure. Catalyst life will have a large impact on the cost effectiveness of this potential process. A mobile catalyst test unit was used to test the activity of four different catalyst materials for a period of up to six months each at three utility sites. Catalyst testing was completed at the first site, which fires Texas lignite, in December 1998; at the second test site, which fires a Powder River Basin subbituminous coal, in November 1999; and at the third site, which fires a medium- to high-sulfur bituminous coal, in January 2001. Results of testing at each of the three sites were reported in previous technical notes. At Site 1, catalysts were tested only as powders dispersed in sand bed reactors. At Sites 2 and 3, catalysts were tested in two forms, including powders dispersed in sand and in commercially available forms such as extruded pellets and coated honeycomb structures. This final report summarizes and presents results from all three sites, for the various catalyst forms tested. Field testing was supported by laboratory tests to screen catalysts for activity at specific flue gas compositions, to investigate catalyst deactivation mechanisms and methods for regenerating spent catalysts. Laboratory results are also summarized and discussed in this report.

  12. Anion-exchange resin-based desulfurization process

    SciTech Connect

    Sheth, A.C.; Dharmapurikar, R.

    1992-01-01

    Under DOE Grant No. DE-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. During the reporting period, October 1, 1992--December 31, 1992, UTSI has completed the batch mode experiments to evaluate the performance enhancement effect caused by organic acids on the resin's exhaustion efficiency. At present, batch mode experiments are being conducted to locate the position of the CO[sub 3]= and SO[sub 4]= ions in the affinity chart, and also reviewing/assessing the ASPEN Code's capabilities for use in the development of the Best Process Schematic and related economics.

  13. 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.

  14. 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.

  15. 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. PMID:26428238

  16. 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.

  17. Ultrasonic coal-wash for de-sulfurization.

    PubMed

    Ambedkar, B; Nagarajan, R; Jayanti, S

    2011-05-01

    Coal is the one of the world's most abundant fossil fuel resources. It is not a clean fuel, as it contains ash and sulfur. SOx as a pollutant are a real threat to both the ecosystem and to human health. There are numerous de-sulfurization methods to control SO(2) emissions. Nowadays, online flue gas de-sulfurization is being used as one such method to remove sulfur from coal during combustion. The biggest disadvantage associated with this method is formation of by-products (FGD gypsum). A way for effective usage of FGD gypsum has not yet been found. This will lead to acute and chronic effects to humans as well as plants. Power ultrasound can be used for the beneficiation of coal by the removal of sulfur from coal prior to coal combustion. The main effects of ultrasound in liquid medium are acoustic cavitation and acoustic streaming. The process of formation, growth and implosion of bubbles is called cavitation. Bulk fluid motion due to sound energy absorption is known as acoustic streaming. In addition, coupling of an acoustic field to water produces OH radicals, H(2)O(2), O(2), ozone and HO(2) that are strong oxidizing agents. Oxidation that occurs due to ultrasound is called Advanced Oxidation Process (AOP). It converts sulfur from coal to water-soluble sulphates. Conventional chemical-based soaking and stirring methods are compared here to ultrasonic methods of de-sulfurization. The main advantages of ultrasonic de-sulfurization over conventional methods, the mechanism involved in ultrasonic de-sulfurization and the difference between aqueous-based and solvent-based (2N HNO(3), 3-volume percentage H(2)O(2)) de-sulfurization are investigated experimentally. PMID:21115263

  18. 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.

  19. 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.

  20. 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.

  1. Flue gas desulfurization information system (FGDIS) data base user's manual

    SciTech Connect

    Smith, M.

    1981-03-01

    This manual is intended to provide a guide to the use of the Flue Gas Desulfurization Information System (FGDIS) data base which is a collection of data files consisting of information pertaining to the design and performance of flue gas desulfurization (FGD) systems. The files are stored at the U.S. Environmental Protection Agency National Computer Center (NCC), Research Triangle Park, NC. Access to these files and manipulation of the data therein is accomplished via System 2000, general data base management system developed by INTEL Corp. and supported by the NCC Univac 1100 hardware.

  2. 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.

  3. Desulfurization of coal: Enhanced selectivity using phase transfer catalysts. Final technical report, September 1, 1995--August 31, 1996

    SciTech Connect

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

    1997-05-01

    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 investigated the application of phase transfer catalysts to the selective oxidation of sulfur in coal using air and oxygen as oxidants. The phase transfer catalyst was 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 were also studied. If successful this project would have lead to the rapid development of a commercially viable desulfurization process. This would have significantly improved the marketability of Illinois coal. However, the phase transfer catalysts, the cerium and the scrubber sledge did not catalize the sulfur removal significantly.

  4. A novel three phase fluidized bed process for simultaneous selective flocculation and microbial desulfurization of high sulfur coal

    SciTech Connect

    Fan, Liang-Shih; Bavarian, F.; Attia, Y.A.; Elzeky, M. )

    1990-10-16

    The purpose of this work was to investigate the feasibility of recovery and reclamation of ultrafine coal particles generated during the processing of coal. 10--35% of the total annual tonnage of coal in atypical coal preparation plant is estimated to be lost in forms of ultrafine particles during the mining, shipping, handling, and preparation of the coal. The technical feasibility of the proposed system which consisted of an integrated circuit of selective flocculation followed by microbial desulfurization, has been tested. The results indicate that using selective flocculation/froth flotation circuit, coal recoveryis 85% with 75% pyritic sulfur and 60% ash rejections. The remaining pyritic sulfur in the coal slurry was treated using microbial desulfurization in a draft-tube fluidized bed bioreactor. Using this reactor scheme considerable enhancement of the bioleaching rate was obtained. The results indicate that 90% rejection of pyritic sulfur can be achieved in less than 24 hrs. Note that the previously reported data for the bioleaching rate are from 4 to 12 days for the same amount of pyritic rejection. The results obtained in this work closely reflects the anticipated outcomes which were projected in the original proposal. Consequently, the results of this work implies a significant improvement in bioleaching process and the possibility for the commercialization of the microbial desulfurization process. Our results also indicate further improvement of this process by optimization of reactor sequence and operating conditions.

  5. A novel three phase fluidized bed process for simultaneous selective flocculation and microbial desulfurization of high sulfur coal. Final report

    SciTech Connect

    Fan, Liang-Shih; Bavarian, F.; Attia, Y.A.; Elzeky, M.

    1990-10-16

    The purpose of this work was to investigate the feasibility of recovery and reclamation of ultrafine coal particles generated during the processing of coal. 10--35% of the total annual tonnage of coal in atypical coal preparation plant is estimated to be lost in forms of ultrafine particles during the mining, shipping, handling, and preparation of the coal. The technical feasibility of the proposed system which consisted of an integrated circuit of selective flocculation followed by microbial desulfurization, has been tested. The results indicate that using selective flocculation/froth flotation circuit, coal recoveryis 85% with 75% pyritic sulfur and 60% ash rejections. The remaining pyritic sulfur in the coal slurry was treated using microbial desulfurization in a draft-tube fluidized bed bioreactor. Using this reactor scheme considerable enhancement of the bioleaching rate was obtained. The results indicate that 90% rejection of pyritic sulfur can be achieved in less than 24 hrs. Note that the previously reported data for the bioleaching rate are from 4 to 12 days for the same amount of pyritic rejection. The results obtained in this work closely reflects the anticipated outcomes which were projected in the original proposal. Consequently, the results of this work implies a significant improvement in bioleaching process and the possibility for the commercialization of the microbial desulfurization process. Our results also indicate further improvement of this process by optimization of reactor sequence and operating conditions.

  6. Flue gas desulfurization by rotating beds

    SciTech Connect

    Gardner, N.; Keyvani, M.; Coskundeniz, A.

    1992-01-01

    The operating and mass transfer characteristics of rotating foam metal beds were studied to determine the potential for flue gas desulfurization. This is a final technical report on the work supported by DOE [number sign]FG22-87-PC79924. The report is divided into two sections, Part 1 deals primarily with the operating characteristics of rotating beds, and Part 2 covers the mass transfer characteristics of S0[sub 2] absorption in water-lime slurries. Rotating foam metal beds are in essence packed towers operated in high gravitational fields. The foam metal bed is in the form of a cylindrical donut, or torus, and is rotated to produced the high centrifugal forces. The liquid phase enters the bed at the inner surface of the torus and is pulled by the field through the bed. Gas flows countercurrent to the liquid. The bed packing can have a very large specific surface areas and not flood. Possible benefits include much smaller height of a transfer unit resulting in smaller equipment and supporting structures, reduced solvent inventory, faster response with improved process control, reduced pressure drop, and shorter startup and shut-down times. This work is concerned broadly with the operating characteristics of rotating beds, the objectives being to (1) determine the pressure drop through the rotating bed; (2) determine the power required to operate the beds, (3) investigate the residence time distribution of the liquid phase in the beds; and (4) determine the mass transfer coefficients of S0[sub 2] absorption. Three packings of differing specific surface areas were studied, with areas ranging from 656 to 2952 m[sub 2]/m[sub 3]. Liquid flow rates to 36 kg/s*m[sub 2], gas flow rate to 2.2 kg/s*m[sub 2], and gravitational fields to 300 g were covered in this study.

  7. 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.

  8. Enhanced durability of high-temperature desulfurization sorbents for fluidized-bed applications. [Zinc titanate

    SciTech Connect

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

    1992-01-01

    The objectives of this project are to identify and demonstrate methods for enhancing long-term chemical reactivity and attrition resistance of zinc ferrite and zinc titanate sorbents to be employed for desulfurization of hot coal-derived gases in a high-temperature, high-pressure (HTHP) fluid-bed reactor. The sorbent formulation specified for study during the base period of this project was zinc ferrite. Zinc titanate sorbents are being studied under two options to the base contract. Specific objectives of the zinc titanate sorbent development work are the following: The effect of following process variables was investigated o the performance of zinc titanate sorbents: Method of sorbent preparation, Composition of fuel gas, Zn to Ti ratio of the sorbent, Sulfidation temperature, and Superficial gas velocity. The effect of first three variables has been covered in RTI's 1991 paper (Gupta and Gangwal, 1991b), while the effect of temperature and superficial gas velocity is described here.

  9. Enhanced durability of high-temperature desulfurization sorbents for fluidized-bed applications

    SciTech Connect

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

    1992-11-01

    The objectives of this project are to identify and demonstrate methods for enhancing long-term chemical reactivity and attrition resistance of zinc ferrite and zinc titanate sorbents to be employed for desulfurization of hot coal-derived gases in a high-temperature, high-pressure (HTHP) fluid-bed reactor. The sorbent formulation specified for study during the base period of this project was zinc ferrite. Zinc titanate sorbents are being studied under two options to the base contract. Specific objectives of the zinc titanate sorbent development work are the following: The effect of following process variables was investigated o the performance of zinc titanate sorbents: Method of sorbent preparation, Composition of fuel gas, Zn to Ti ratio of the sorbent, Sulfidation temperature, and Superficial gas velocity. The effect of first three variables has been covered in RTI`s 1991 paper (Gupta and Gangwal, 1991b), while the effect of temperature and superficial gas velocity is described here.

  10. GYPSUM CRYSTALLIZATION FOR LIMESTONE FGD (FLUE GAS DESULFURIZATION)

    EPA Science Inventory

    The paper gives results of pilot plant tests using a double draw-off crystallizer as the hold tank to improve the gypsum dewatering properties of a forced oxidation limestone flue gas desulfurization process. A hydroclone was used as the size classification device for solids sepa...

  11. EVALUATION OF GYPSUM CRYSTALLIZATION FOR LIMESTONE FLUE GAS DESULFURIZATION

    EPA Science Inventory

    The paper gives results of pilot plant tests using a double draw-off crystallizer as the hold tank to improve the gypsum dewatering properties of a forced oxidation limestone flue gas desulfurization process. A hydroclone was used as the size classification device for solids sepa...

  12. 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...

  13. CURRENT STATUS OF COMMERCIAL UTILITY FLUE GAS DESULFURIZATION SYSTEMS

    EPA Science Inventory

    The report discusses the current status of commercial flue gas desulfurization (FGD) processes applied to coal-fired utility boilers in the U.S. Major objectives of the work were to examine the impacts of the 1979 New Source Performance Standards on FGD system design and operatio...

  14. FLUE GAS DESULFURIZATION INFORMATION SYSTEM (FGDIS) DATA BASE USER'S MANUAL

    EPA Science Inventory

    The document is a user's manual and reference book/primer for Flue Gas Desulfurization Information System (FGDIS) users and recipients of the quarterly Utility FGD Survey. Part I, interactive computer procedures for the FGDIS, addresses the use of and terminology related to the u...

  15. 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)

  16. Effect of Flue Gas Desulfurization Waste on Corn Plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flue gas desulfurization gypsum (FGDG) is a by-product of conversion of sulfur dioxide into solid waste from coal combustion power generation plant. This by-product is rich in calcium, magnesium, and contains various other essential plant nutrients. The beneficial use of application of this waste as...

  17. 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.

  18. MARKETING OF BYPRODUCT GYPSUM FROM FLUE GAS DESULFURIZATION

    EPA Science Inventory

    The report gives results of an evaluation of the 1985 marketing potential of byproduct gypsum from utility flue gas desulfurization (FGD), for the area east of the Rocky Mountains, using the calculated gypsum production rates of 14 selected power plants. The 114 cement plants and...

  19. 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.

  20. EPA UTILITY FGD (FLUE GAS DESULFURIZATION): AUGUST-SEPTEMBER, 1978

    EPA Science Inventory

    The report is an updated supplement to EPA-600/7-78-051a and should be used in conjunction with it. It presents a survey of utility flue gas desulfurization (FGD) systems in the U.S., summarizing information contributed by the utility industry, process suppliers, regulatory agenc...

  1. FLUE GAS DESULFURIZATION INSPECTION AND PERFORMANCE EVALUATION. MANUAL

    EPA Science Inventory

    The intent of the manual is to provide inspectors from Federal and state environmental agencies with information regarding the problems that plague lime/limestone slurry flue gas desulfurization (FGD) systems that will aid them in their inspections and performance evaluations of ...

  2. FLUE GAS DESULFURIZATION: THE STATE OF THE ART: JOURNAL ARTICLE

    EPA Science Inventory

    Srivastava*, R.K., and Jozewicz, W. Flue Gas Desulfurization: The State of the Art. Journal of Air and Waste Management Association (Air & Waste Management Asiciation) 51 (12):1676-88 (2001). EPA/600/J-01/391, Available: Journal of Air and Waste Management Association (journal)...

  3. 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...

  4. 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.

  5. 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. PMID:16856750

  6. Two-Input Enzymatic Logic Gates Made Sigmoid by Modifications of the Biocatalytic Reaction Cascades

    SciTech Connect

    Zavalov, Oleksandr; Bocharova, Vera; Halamek, Jan; Halamkova, Lenka; Korkmaz, Sevim; Arugula, Mary; Chinnapareddy, Soujanya; Katz, Evgeny; Privman, Vladimir

    2012-01-01

    Computing based on biochemical processes is a newest rapidly developing field of unconventional information and signal processing. In this paper we present results of our research in the field of biochemical computing and summarize the obtained numerical and experimental data for implementations of the standard two-input OR and AND gates with double-sigmoid shape of the output signal. This form of response was obtained as a function of the two inputs in each of the realized biochemical systems. The enzymatic gate processes in the first system were activated with two chemical inputs and resulted in optically detected chromogen oxidation, which happens when either one or both of the inputs are present. In this case, the biochemical system is functioning as the OR gate. We demonstrate that the addition of a filtering biocatalytic process leads to a considerable reduction of the noise transmission factor and the resulting gate response has sigmoid shape in both inputs. The second system was developed for functioning as an AND gate, where the output signal was activated only by a simultaneous action of two enzymatic biomarkers. This response can be used as an indicator of liver damage, but only if both of these of the inputs are present at their elevated, pathophysiological values of concentrations. A kinetic numerical model was developed and used to estimate the range of parameters for which the experimentally realized logic gate is close to optimal. We also analyzed the system to evaluate its noise-handling properties.

  7. Biocatalytic Production of Trehalose from Maltose by Using Whole Cells of Permeabilized Recombinant Escherichia coli.

    PubMed

    Zheng, Zhaojuan; Xu, Ying; Sun, Ye; Mei, Wending; Ouyang, Jia

    2015-01-01

    Trehalose is a non-reducing disaccharide, which can protect proteins, lipid membranes, and cells from desiccation, refrigeration, dehydration, and other harsh environments. Trehalose can be produced by different pathways and trehalose synthase pathway is a convenient, practical, and low-cost pathway for the industrial production of trehalose. In this study, 3 candidate treS genes were screened from genomic databases of Pseudomonas and expressed in Escherichia coli. One of them from P. stutzeri A1501 exhibited the best transformation ability from maltose into trehalose and the least byproduct. Thus, whole cells of this recombinant E. coli were used as biocatalyst for trehalose production. In order to improve the conversion rate of maltose to trehalose, optimization of the permeabilization and biotransformation were carried out. Under optimal conditions, 92.2 g/l trehalose was produced with a high productivity of 23.1 g/(l h). No increase of glucose was detected during the whole course. The biocatalytic process developed in this study might serve as a candidate for the large scale production of trehalose. PMID:26462117

  8. Cellulose Digestion and Metabolism Induced Biocatalytic Transitions in Anaerobic Microbial Ecosystems

    PubMed Central

    Yamazawa, Akira; Iikura, Tomohiro; Morioka, Yusuke; Shino, Amiu; Ogata, Yoshiyuki; Date, Yasuhiro; Kikuchi, Jun

    2013-01-01

    Anaerobic digestion of highly polymerized biomass by microbial communities present in diverse microbial ecosystems is an indispensable metabolic process for biogeochemical cycling in nature and for industrial activities required to maintain a sustainable society. Therefore, the evaluation of the complicated microbial metabolomics presents a significant challenge. We here describe a comprehensive strategy for characterizing the degradation of highly crystallized bacterial cellulose (BC) that is accompanied by metabolite production for identifying the responsible biocatalysts, including microorganisms and their metabolic functions. To this end, we employed two-dimensional solid- and one-dimensional solution-state nuclear magnetic resonance (NMR) profiling combined with a metagenomic approach using stable isotope labeling. The key components of biocatalytic reactions determined using a metagenomic approach were correlated with cellulose degradation and metabolic products. The results indicate that BC degradation was mediated by cellulases that contain carbohydrate-binding modules and that belong to structural type A. The degradation reactions induced the metabolic dynamics of the microbial community and produced organic compounds, such as acetic acid and propionic acid, mainly metabolized by clostridial species. This combinatorial, functional and structural metagenomic approach is useful for the comprehensive characterization of biomass degradation, metabolic dynamics and their key components in diverse ecosystems. PMID:24958386

  9. Expedient synthesis of C-aryl carbohydrates by consecutive biocatalytic benzoin and aldol reactions.

    PubMed

    Hernández, Karel; Parella, Teodor; Joglar, Jesús; Bujons, Jordi; Pohl, Martina; Clapés, Pere

    2015-02-16

    The introduction of aromatic residues connected by a C-C bond into the non-reducing end of carbohydrates is highly significant for the development of innovative structures with improved binding affinity and selectivity (e.g., C-aril-sLex). In this work, an expedient asymmetric "de novo" synthetic route to new aryl carbohydrate derivatives based on two sequential stereoselectively biocatalytic carboligation reactions is presented. First, the benzoin reaction of aromatic aldehydes to dimethoxyacetaldehyde is conducted, catalyzed by benzaldehyde lyase from Pseudomonas fluorescens biovar I. Then, the α-hydroxyketones formed are reduced by using NaBH4 yielding the anti diol. After acetal hydrolysis, the aldol addition of dihydroxyacetone, hydroxyacetone, or glycolaldehyde catalyzed by the stereocomplementary D-fructose-6-phosphate aldolase and L-rhamnulose-1-phosphate aldolase is performed. Both aldolases accept unphosphorylated donor substrates, avoiding the need of handling the phosphate group that the dihydroxyacetone phosphate-dependent aldolases require. In this way, 6-C-aryl-L-sorbose, 6-C-aryl-L-fructose, 6-C-aryl-L-tagatose, and 5-C-aryl-L-xylose derivatives are prepared by using this methodology. PMID:25640727

  10. Discovery and molecular and biocatalytic properties of hydroxynitrile lyase from an invasive millipede, Chamberlinius hualienensis

    PubMed Central

    Dadashipour, Mohammad; Ishida, Yuko; Yamamoto, Kazunori; Asano, Yasuhisa

    2015-01-01

    Hydroxynitrile lyase (HNL) catalyzes the degradation of cyanohydrins and causes the release of hydrogen cyanide (cyanogenesis). HNL can enantioselectively produce cyanohydrins, which are valuable building blocks for the synthesis of fine chemicals and pharmaceuticals, and is used as an important biocatalyst in industrial biotechnology. Currently, HNLs are isolated from plants and bacteria. Because industrial biotechnology requires more efficient and stable enzymes for sustainable development, we must continuously explore other potential enzyme sources for the desired HNLs. Despite the abundance of cyanogenic millipedes in the world, there has been no precise study of the HNLs from these arthropods. Here we report the isolation of HNL from the cyanide-emitting invasive millipede Chamberlinius hualienensis, along with its molecular properties and application in biocatalysis. The purified enzyme displays a very high specific activity in the synthesis of mandelonitrile. It is a glycosylated homodimer protein and shows no apparent sequence identity or homology with proteins in the known databases. It shows biocatalytic activity for the condensation of various aromatic aldehydes with potassium cyanide to produce cyanohydrins and has high stability over a wide range of temperatures and pH values. It catalyzes the synthesis of (R)-mandelonitrile from benzaldehyde with a 99% enantiomeric excess, without using any organic solvents. Arthropod fauna comprise 80% of terrestrial animals. We propose that these animals can be valuable resources for exploring not only HNLs but also diverse, efficient, and stable biocatalysts in industrial biotechnology. PMID:26261304

  11. Techno-economic analysis of biocatalytic processes for production of alkene epoxides.

    PubMed

    Borole, Abhijeet P; Davison, Brian H

    2007-04-01

    A techno-economic analysis of two different bioprocesses was conducted, one for the conversion of propylene to propylene oxide (PO) and other for conversion of styrene to styrene epoxide (SO). The first process was a lipase-mediated chemo-enzymatic reaction, whereas the second one was a one-step enzymatic process using chloroperoxidase. The PO produced through the chemo-enzymatic process is a racemic product, whereas the latter process (based on chloroperoxidase) produces an enantio-pure product. The former process thus falls under the category of high-volume commodity chemical (PO); whereas the latter is a low-volume, high-value product (SO).A simulation of the process was conducted using the bioprocess engineering software SuperPro Designer v6.0 (Intelligen, Inc., Scotch Plains, NJ) to determine the economic feasibility of the process. The purpose of the exercise was to compare biocatalytic processes with existing chemical processes for production of alkene expoxides. The results show that further improvements are needed in improving biocatalyst stability to make these bioprocesses competitive with chemical processes. PMID:18478407

  12. Building carbon-carbon bonds using a biocatalytic methanol condensation cycle.

    PubMed

    Bogorad, Igor W; Chen, Chang-Ting; Theisen, Matthew K; Wu, Tung-Yun; Schlenz, Alicia R; Lam, Albert T; Liao, James C

    2014-11-11

    Methanol is an important intermediate in the utilization of natural gas for synthesizing other feedstock chemicals. Typically, chemical approaches for building C-C bonds from methanol require high temperature and pressure. Biological conversion of methanol to longer carbon chain compounds is feasible; however, the natural biological pathways for methanol utilization involve carbon dioxide loss or ATP expenditure. Here we demonstrated a biocatalytic pathway, termed the methanol condensation cycle (MCC), by combining the nonoxidative glycolysis with the ribulose monophosphate pathway to convert methanol to higher-chain alcohols or other acetyl-CoA derivatives using enzymatic reactions in a carbon-conserved and ATP-independent system. We investigated the robustness of MCC and identified operational regions. We confirmed that the pathway forms a catalytic cycle through (13)C-carbon labeling. With a cell-free system, we demonstrated the conversion of methanol to ethanol or n-butanol. The high carbon efficiency and low operating temperature are attractive for transforming natural gas-derived methanol to longer-chain liquid fuels and other chemical derivatives. PMID:25355907

  13. Microbiome and Biocatalytic Bacteria in Monkey Cup (Nepenthes Pitcher) Digestive Fluid.

    PubMed

    Chan, Xin-Yue; Hong, Kar-Wai; Yin, Wai-Fong; Chan, Kok-Gan

    2016-01-01

    Tropical carnivorous plant, Nepenthes, locally known as "monkey cup", utilises its pitcher as a passive trap to capture insects. It then secretes enzymes into the pitcher fluid to digest the insects for nutrients acquisition. However, little is known about the microbiota and their activity in its pitcher fluid. Eighteen bacteria phyla were detected from the metagenome study in the Nepenthes pitcher fluid. Proteobacteria, Bacteroidetes and Actinobacteria are the dominant phyla in the Nepenthes pitcher fluid. We also performed culturomics approach by isolating 18 bacteria from the Nepenthes pitcher fluid. Most of the bacterial isolates possess chitinolytic, proteolytic, amylolytic, and cellulolytic and xylanolytic activities. Fifteen putative chitinase genes were identified from the whole genome analysis on the genomes of the 18 bacteria isolated from Nepenthes pitcher fluid and expressed for chitinase assay. Of these, six clones possessed chitinase activity. In conclusion, our metagenome result shows that the Nepenthes pitcher fluid contains vast bacterial diversity and the culturomic studies confirmed the presence of biocatalytic bacteria within the Nepenthes pitcher juice which may act in symbiosis for the turn over of insects trapped in the Nepenthes pitcher fluid. PMID:26817720

  14. Building Bridges: Biocatalytic C–C-Bond Formation toward Multifunctional Products

    PubMed Central

    2016-01-01

    Carbon–carbon bond formation is the key reaction for organic synthesis to construct the carbon framework of organic molecules. The review gives a selection of biocatalytic C–C-bond-forming reactions which have been investigated during the last 5 years and which have already been proven to be applicable for organic synthesis. In most cases, the reactions lead to products functionalized at the site of C–C-bond formation (e.g., α-hydroxy ketones, aminoalcohols, diols, 1,4-diketones, etc.) or allow to decorate aromatic and heteroaromatic molecules. Furthermore, examples for cyclization of (non)natural precursors leading to saturated carbocycles are given as well as the stereoselective cyclopropanation of olefins affording cyclopropanes. Although many tools are already available, recent research also makes it clear that nature provides an even broader set of enzymes to perform specific C–C coupling reactions. The possibilities are without limit; however, a big library of variants for different types of reactions is required to have the specific enzyme for a desired specific (stereoselective) reaction at hand. PMID:27398261

  15. Building carbon–carbon bonds using a biocatalytic methanol condensation cycle

    PubMed Central

    Bogorad, Igor W.; Chen, Chang-Ting; Theisen, Matthew K.; Wu, Tung-Yun; Schlenz, Alicia R.; Lam, Albert T.; Liao, James C.

    2014-01-01

    Methanol is an important intermediate in the utilization of natural gas for synthesizing other feedstock chemicals. Typically, chemical approaches for building C–C bonds from methanol require high temperature and pressure. Biological conversion of methanol to longer carbon chain compounds is feasible; however, the natural biological pathways for methanol utilization involve carbon dioxide loss or ATP expenditure. Here we demonstrated a biocatalytic pathway, termed the methanol condensation cycle (MCC), by combining the nonoxidative glycolysis with the ribulose monophosphate pathway to convert methanol to higher-chain alcohols or other acetyl-CoA derivatives using enzymatic reactions in a carbon-conserved and ATP-independent system. We investigated the robustness of MCC and identified operational regions. We confirmed that the pathway forms a catalytic cycle through 13C-carbon labeling. With a cell-free system, we demonstrated the conversion of methanol to ethanol or n-butanol. The high carbon efficiency and low operating temperature are attractive for transforming natural gas-derived methanol to longer-chain liquid fuels and other chemical derivatives. PMID:25355907

  16. Silver Iodide-Chitosan Nanotag Induced Biocatalytic Precipitation for Self-Enhanced Ultrasensitive Photocathodic Immunosensor.

    PubMed

    Gong, Lingshan; Dai, Hong; Zhang, Shupei; Lin, Yanyu

    2016-06-01

    In this work, we first exposed that the application of p-type semiconductor, silver iodide-chitosan nanoparticle (SICNP), acted as peroxidase mimetic to catalyze the bioprecipitation reaction for signal-amplification photocathodic immunosensing of human interleukin-6 (IL-6). After immobilization of captured antibody onto a polyethylenimine-functionalized carbon nitride (CN) matrix, SICNPs as photoactive tags and peroxidase mimetics were labeled on secondary antibodies, which were subsequently introduced onto the sensing interface to construct sandwich immunoassay platform through antigen-antibody specific recognition. Due to the matched energy levels between CN and AgI, the photocurrent intensity and photostability of SICNP were dramatically improved with rapid separation and transportation of photogenerated carriers. Moreover, the insoluble product in effective biocatalytic precipitation reaction served as electron acceptor to scavenge the photoexcited electron, leading to great amplification of the photocurrent signal of SICNP again. With the help of multiamplification processes, this photocathodic immunosensor presented a turn-on photoelectrochemical performance for IL-6, which showed wide linear dynamic range from 10(-6) to 10 pg/mL with the ultralow detection limit of 0.737 ag/mL. This work also performed the promising application of SICNP in developing an ultrasensitive, cost-effective, and enzyme-free photocathodic immunosensor for biomarkers. PMID:27180822

  17. Biocatalytic Production of Trehalose from Maltose by Using Whole Cells of Permeabilized Recombinant Escherichia coli

    PubMed Central

    Sun, Ye; Mei, Wending; Ouyang, Jia

    2015-01-01

    Trehalose is a non-reducing disaccharide, which can protect proteins, lipid membranes, and cells from desiccation, refrigeration, dehydration, and other harsh environments. Trehalose can be produced by different pathways and trehalose synthase pathway is a convenient, practical, and low-cost pathway for the industrial production of trehalose. In this study, 3 candidate treS genes were screened from genomic databases of Pseudomonas and expressed in Escherichia coli. One of them from P. stutzeri A1501 exhibited the best transformation ability from maltose into trehalose and the least byproduct. Thus, whole cells of this recombinant E. coli were used as biocatalyst for trehalose production. In order to improve the conversion rate of maltose to trehalose, optimization of the permeabilization and biotransformation were carried out. Under optimal conditions, 92.2 g/l trehalose was produced with a high productivity of 23.1 g/(l h). No increase of glucose was detected during the whole course. The biocatalytic process developed in this study might serve as a candidate for the large scale production of trehalose. PMID:26462117

  18. Characterisation of a Recombinant Patchoulol Synthase Variant for Biocatalytic Production of Terpenes.

    PubMed

    Frister, Thore; Hartwig, Steffen; Alemdar, Semra; Schnatz, Katharina; Thöns, Laura; Scheper, Thomas; Beutel, Sascha

    2015-08-01

    The patchoulol synthase (PTS) is a multi-product sesquiterpene synthases which is the central enzyme for biosynthesis of patchouli essential oil in the patchouli plant. Sesquiterpene synthases catalyse the formation of various complex carbon backbones difficult to approach by organic synthesis. Here, we report the characterisation of a recombinant patchoulol synthase complementary DNA (cDNA) variant (PTS var. 1), exhibiting significant amino acid exchanges compared to the native PTS. The product spectrum using the natural substrate E,E-farnesyl diphosphate (FDP) as well as terpenoid products resulting from conversions employing alternative substrates was analysed by GC-MS. In respect to a potential use as a biocatalyst, important enzymatic parameters such as the optimal reaction conditions, kinetic behaviour and the product selectivity were studied as well. Adjusting the reaction conditions, an increased patchoulol ratio in the recombinant essential oil was achieved. Nevertheless, the ratio remained lower than in plant-derived patchouli oil. As alternative substrates, several prenyl diposphates were accepted and converted in numerous compounds by the PTS var. 1, revealing its great biocatalytic potential. PMID:26100386

  19. Biocatalytically induced growth of gold nanoshells: using enzyme reaction for the controllable fabrication of nanomaterials.

    PubMed

    Ma, Xiaoyuan; Liu, Liangliang; Liu, Fangjing; Qian, Weiping

    2012-02-01

    In the present work, the enzymatically controlled growth process of gold nanoshells (GNSs) in the presence of O2/glucose/glucose oxidase (GOx) and its chloroaurate ion electron acceptor is described. The biocatalytically stimulated growth process is one of the bio-inspired synthetic procedures directed by biological molecules which occur under ambient conditions. It is found that hydrogen peroxide (H2O2) could enlarge the gold nanoparticles (GNPs) on the surface of GNSs precursor composites, of which the preadsorbed GNPs serve as nucleation sites for further gold deposition. Here, GOx is harnessed for its unparalled level of catalytic activity and substrate specificity while H2O2 is produced as a by-product during the oxidation of D-glucose to gluconic acid by GOx. Then the bio-generated H2O2 is used as the reducing agent in the catalytic deposition process of GNSs formation. During the procedure, the localized surface plasmon resonance peaks range across hundreds of nanometers from visible to near infrared region accompanying by the resultant formation of uniform and continuous core-shell nanostructures. The corresponding optical, morphological and enzyme kinetic properties are all well investigated. The novel protocol offers a new perspective for the bio-directed synthesis method in nanotechnology. PMID:22629867

  20. Microbiome and Biocatalytic Bacteria in Monkey Cup (Nepenthes Pitcher) Digestive Fluid

    PubMed Central

    Chan, Xin-Yue; Hong, Kar-Wai; Yin, Wai-Fong; Chan, Kok-Gan

    2016-01-01

    Tropical carnivorous plant, Nepenthes, locally known as “monkey cup”, utilises its pitcher as a passive trap to capture insects. It then secretes enzymes into the pitcher fluid to digest the insects for nutrients acquisition. However, little is known about the microbiota and their activity in its pitcher fluid. Eighteen bacteria phyla were detected from the metagenome study in the Nepenthes pitcher fluid. Proteobacteria, Bacteroidetes and Actinobacteria are the dominant phyla in the Nepenthes pitcher fluid. We also performed culturomics approach by isolating 18 bacteria from the Nepenthes pitcher fluid. Most of the bacterial isolates possess chitinolytic, proteolytic, amylolytic, and cellulolytic and xylanolytic activities. Fifteen putative chitinase genes were identified from the whole genome analysis on the genomes of the 18 bacteria isolated from Nepenthes pitcher fluid and expressed for chitinase assay. Of these, six clones possessed chitinase activity. In conclusion, our metagenome result shows that the Nepenthes pitcher fluid contains vast bacterial diversity and the culturomic studies confirmed the presence of biocatalytic bacteria within the Nepenthes pitcher juice which may act in symbiosis for the turn over of insects trapped in the Nepenthes pitcher fluid. PMID:26817720

  1. Preparation of biocatalytic nanofibres with high activity and stability via enzyme aggregate coating on polymer nanofibres

    NASA Astrophysics Data System (ADS)

    Kim, Byoung Chan; Nair, Sujith; Kim, Jungbae; Kwak, Ja Hun; Grate, Jay W.; Kim, Seong H.; Gu, Man Bock

    2005-07-01

    We have developed a unique approach for the fabrication of enzyme aggregate coatings on the surfaces of electrospun polymer nanofibres. This approach employs covalent attachment of seed enzymes onto nanofibres consisting of a mixture of polystyrene and poly(styrene-co-maleic anhydride), followed by a glutaraldehyde (GA) treatment that cross-links additional enzyme molecules and aggregates from the solution onto the covalently attached seed enzyme molecules. These cross-linked enzyme aggregates, covalently attached to the nanofibres via the linkers of seed enzyme molecules, are expected to improve the enzyme activity due to increased enzyme loading, and also the enzyme stability. To demonstrate the principle, we coated α-chymotrypsin (CT) on nanofibres electrospun from a mixture of polystyrene and poly(styrene-co-maleic anhydride). The initial activity of CT-aggregate-coated nanofibres was nine times higher than nanofibres with just a layer of covalently attached CT molecules. The enzyme stability of CT-aggregate-coated nanofibres was greatly improved with essentially no measurable loss of activity over a month of observation under rigorous shaking conditions. This new approach of enzyme coating on nanofibres, yielding high activity and stability, creates a useful new biocatalytic immobilized enzyme system with potential applications in bioconversion, bioremediation, and biosensors.

  2. Separation, Immobilization, and Biocatalytic Utilization of Proteins by a Supramolecular Membrane

    PubMed Central

    Krieg, Elisha; Albeck, Shira; Weissman, Haim; Shimoni, Eyal; Rybtchinski, Boris

    2013-01-01

    Membrane separation of biomolecules and their application in biocatalysis is becoming increasingly important for biotechnology, demanding the development of new biocompatible materials with novel properties. In the present study, an entirely noncovalent water-based material is used as a membrane for size-selective separation, immobilization, and biocatalytic utilization of proteins. The membrane shows stable performance under physiological conditions, allowing filtration of protein mixtures with a 150 kDa molecular weight cutoff (∼8 nm hydrodynamic diameter cutoff). Due to the biocompatibility of the membrane, filtered proteins stay functionally active and retained proteins can be partially recovered. Upon filtration, large enzymes become immobilized within the membrane. They exhibit stable activity when subjected to a constant flux of substrates for prolonged periods of time, which can be used to carry out heterogeneous biocatalysis. The noncovalent membrane material can be easily disassembled, purified, reassembled, and reused, showing reproducible performance after recycling. The robustness, recyclability, versatility, and biocompatibility of the supramolecular membrane may open new avenues for manipulating biological systems. PMID:23675461

  3. Enzyme-Modified Particles for Selective Biocatalytic Hydrogenation by Hydrogen-Driven NADH Recycling

    PubMed Central

    Reeve, Holly A; Lauterbach, Lars; Lenz, Oliver; Vincent, Kylie A

    2015-01-01

    We describe a new approach to selective H2-driven hydrogenation that exploits a sequence of enzymes immobilised on carbon particles. We used a catalyst system that comprised alcohol dehydrogenase, hydrogenase and an NAD+ reductase on carbon black to demonstrate a greater than 98 % conversion of acetophenone to phenylethanol. Oxidation of H2 by the hydrogenase provides electrons through the carbon for NAD+ reduction to recycle the NADH cofactor required by the alcohol dehydrogenase. This biocatalytic system operates over the pH range 6–8 or in un-buffered water, and can function at low concentrations of the cofactor (10 μm NAD+) and at H2 partial pressures below 1 bar. Total turnover numbers >130 000 during acetophenone reduction indicate high enzyme stability, and the immobilised enzymes can be recovered by a simple centrifugation step and re-used several times. This offers a route to convenient, atom-efficient operation of NADH-dependent oxidoreductases for selective hydrogenation catalysis. PMID:26613009

  4. 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.

  5. 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

  6. Mechanistic analysis of ultrasound assisted enzymatic desulfurization of liquid fuels using horseradish peroxidase.

    PubMed

    Bhasarkar, Jaykumar; Borah, Arup Jyoti; Goswami, Pranab; Moholkar, Vijayanand S

    2015-11-01

    This study has attempted to gain physical insight into ultrasound-assisted enzymatic desulfurization using system comprising horseradish peroxidase enzyme and dibenzothiophene (DBT). Desulfurization pathway (comprising DBT-sulfoxide and DBT-sulfone as intermediates and 4-methoxy benzoic acid as final product) has been established with GC-MS analysis. Intrinsic fluorescence and circular dichroism spectra of ultrasound-treated enzyme reveal conformational changes in secondary structure (reduction in α-helix and β-conformations and increase in random coil content) leading to enhancement in activity. Concurrent analysis of desulfurization profiles, Arrhenius and thermodynamic parameters, and simulations of cavitation bubble dynamics reveal that strong micro-convection generated by sonication enhances enzyme activity and desulfurization kinetics. Parallel oxidation of DBT by radicals generated from transient cavitation gives further boost to desulfurization kinetics. However, random motion of enzyme molecules induced by shock waves reduces frequency factor and limits the ultrasonic enhancement of enzymatic desulfurization. PMID:26231128

  7. A novel system combining biocatalytic dephosphorylation of L-ascorbic acid 2-phosphate and electrochemical oxidation of resulting ascorbic acid.

    PubMed

    Kuwahara, Takashi; Homma, Toshimasa; Kondo, Mizuki; Shimomura, Masato

    2011-03-15

    An enzyme electrode was prepared with acid phosphatase (ACP) for development of a new electric power generation system using ascorbic acid 2-phosphate (AA2P) as a fuel. The properties of the electrode were investigated with respect to biocatalytic dephosphorylation of AA2P and electrochemical oxidation of resulting ascorbic acid (AA). The enzyme electrode was fabricated by immobilization of ACP through amide linkage onto a self-assembled monolayer of 3-mercaptopropionic acid on a gold electrode. AA2P was not oxidized on a bare gold electrode in the potential sweep range from -0.1 to +0.5 V vs. Ag/AgCl. However, the enzyme electrode gave an oxidation current in citric buffer solution of pH 5 containing 10 mM of AA2P. The oxidation current began to increase at +0.2V, and reached to 5.0 μA cm(-2) at +0.5 V. The potential +0.2 V corresponded to the onset of oxidation of ascorbic acid (AA). These results suggest that the oxidation current observed with the enzyme electrode is due to AA resulting from dephosphorylation of AA2P. The oxidation current increased with increasing concentration of AA2P and almost leveled off at around the concentration of 5mM. Thus the enzyme electrode brought about biocatalytic conversion of AA2P to AA, followed by electrochemical oxidation of the AA. The oxidation current is likely to be controlled by the biocatalytic reaction. PMID:21247749

  8. Retrofit flue gas desulfurization system at Indianapolis Power and Light Co. Petersburg Station Units 1 and 2

    SciTech Connect

    Watson, W.K.; Wolsiffer, S.R. ); Youmans, J.; Martin, J.E.; Wedig, C.P. )

    1992-01-01

    This paper briefly describes the status of the retrofit wet limestone flue gas desulfurization system (FGDS) project at Indianapolis Power and Light Company (IPL), Petersburg Units 1 and 2. This project was initiated by IPL in response to the Clean Air Act of 1990 and is intended to treat the flue gas from two base load units with a combined capacity of approximately 700 MW gross electrical output. IPL is the owner and operator of the Petersburg Station located in southwestern Indiana. Stone and Webster Engineering Corporation (Stone and Webster) is the Engineer and Constructor for the project. Radian Corporation is a subcontractor to Stone and Webster in the area of flue gas desulfurization (FGD) process. General Electric Environmental Systems, Inc. (GEESI) is the supplier of the FGDS. The project is organized as a team with each company providing services. The supplier of the new stack is scheduled to be selected and join the team in early 1992. Other material suppliers and field contractors will be selected in 1992.

  9. Visible-Light-Induced Specific Desulfurization of Cysteinyl Peptide and Glycopeptide in Aqueous Solution.

    PubMed

    Gao, Xiao-Fei; Du, Jing-Jing; Liu, Zheng; Guo, Jun

    2016-03-01

    Visible-light-induced specific desulfurization of cysteinyl peptides has been explored. The photocatalytic desulfurization catalyzed by Ru(bpy)3(2+) can proceed efficiently at room temperature in aqueous solution or in binary mixtures of aqueous/organic solvent and be compatible with the presence of residues of amino acids, carbohydrates, and various sulfur-containing functional groups. This approach was successfully applied to synthesize linear and cyclic peptides through the ligation-desulfurization protocol. PMID:26892036

  10. Biocatalytic conversion of methane to methanol as a key step for development of methane-based biorefineries.

    PubMed

    Hwang, In Yeub; Lee, Seung Hwan; Choi, Yoo Seong; Park, Si Jae; Na, Jeong Geol; Chang, In Seop; Kim, Choongik; Kim, Hyun Cheol; Kim, Yong Hwan; Lee, Jin Won; Lee, Eun Yeol

    2014-12-28

    Methane is considered as a next-generation carbon feedstock owing to the vast reserves of natural and shale gas. Methane can be converted to methanol by various methods, which in turn can be used as a starting chemical for the production of value-added chemicals using existing chemical conversion processes. Methane monooxygenase is the key enzyme that catalyzes the addition of oxygen to methane. Methanotrophic bacteria can transform methane to methanol by inhibiting methanol dehydrogenase. In this paper, we review the recent progress made on the biocatalytic conversion of methane to methanol as a key step for methane-based refinery systems and discuss future prospects for this technology. PMID:25223329

  11. 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.

  12. 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)

  13. Effect of Silicon on Desulfurization of Aluminum-killed Steels

    NASA Astrophysics Data System (ADS)

    Roy, Debdutta

    Recent reports have suggested that silicon has a beneficial effect on the rate of desulfurization of Al-killed steel. This effect is difficult to understand looking at the overall desulfurization reaction which does not include silicon. However an explanation is proposed by taking into account the (SiO2)/[Si] equilibrium in which some Al reaching the slag-metal interface is used in reducing the SiO2 in the slag. This reaction can be suppressed to some extent if the silicon content of the metal is increased and in doing so, more Al will be available at the slag-metal interface for the desulfurization reaction and this would increase the rate of the desulfurization reaction. A model was developed, assuming the rates are controlled by mass transfer, taking into account the coupled reactions of the reduction of silica, and other unstable oxides, namely iron oxide and manganese oxide, in the slag and desulfurization reaction in the steel by aluminum. The model predicts that increasing silicon increases the rate and extent of desulfurization. Plant data was analyzed to obtain rough estimates of ladle desulfurization rates and also used to validate the model predictions. Experiments have been conducted on a kilogram scale of material in an induction furnace to test the hypothesis. The major conclusions of the study are as follows: The rate and extent of desulfurization improve with increasing initial silicon content in the steel; the effect diminishes at silicon contents higher than approximately 0.2% and with increasing slag basicity. This was confirmed with kilogram-scale laboratory experiments. The effects of the silicon content in the steel (and of initial FeO and MnO in the slag) largely arise from the dominant effects of these reactions on the equilibrium aluminum content of the steel: as far as aluminum consumption or pick-up is concerned, the Si/SiO2 reaction dominates, and desulfurization has only a minor effect on aluminum consumption. The rate is primarily

  14. Unraveling heavy oil desulfurization chemistry: targeting clean fuels.

    PubMed

    Choudhary, Tushar V; Parrott, Stephen; Johnson, Byron

    2008-03-15

    The sulfur removal chemistry of heavy oils has been unraveled by systematically investigating several heavy oils with an extremely wide range of properties. The heavy oil feed and product properties have been characterized by advanced analytical methods, and these properties have been related to the sulfur conversion data observed in pilot hydrotreating units. These studies coupled with kinetic treatment of the data have revealed that the desulfurization chemistry of heavy oils is essentially controlled by the strongly inhibiting three and larger ring aromatic hydrocarbon content and surprisingly not by the content of the "hard-to-remove" sulfur compounds. Such enhanced understanding of the heavy oil sulfur removal is expected to open new avenues for catalyst/process optimization for heavy oil desulfurization and thereby assist the efficent production of clean transporation fuels. PMID:18409618

  15. 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.

  16. 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.

  17. Numerical simulation of flow in the wet scrubber for desulfurization

    NASA Astrophysics Data System (ADS)

    Novosád, Jan; Vít, Tomáš

    2015-05-01

    This article deals with numerical simulation of flow and chemical reactions in absorber for desulfurization of flue-gas. The objective of the work is the investigation of effect of different nozzles types and their placement in spray layers. These nozzles distribute lime suspension into flue gas stream. The research includes two types of nozzles and four different arrangements of nozzles and spray layers. Conclusion describes the effect of nozzle types and their arrangements on the suspension concentration in absorber.

  18. 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

  19. Exploring the mechanism of biocatalyst inhibition in microbial desulfurization.

    PubMed

    Abin-Fuentes, Andres; Mohamed, Magdy El-Said; Wang, Daniel I C; Prather, Kristala L J

    2013-12-01

    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

  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. Biocatalytic properties of a recombinant Fusarium proliferatum lactonase with significantly enhanced production by optimal expression in Escherichia coli.

    PubMed

    Chen, Bing; Fan, Li-Qiang; Xu, Jian-He; Zhao, Jian; Zhang, Xian; Ouyang, Li-Ming

    2010-10-01

    The levo-lactonase gene of Fusarium proliferatum ECU2002 (EC3.1.1.25) was cloned and expressed in Escherichia coli JM109 (DE3) for biocatalytic resolution of industrially important chiral lactones, including DL-pantoyl lactone which was a key precursor to calcium D-pantothenate. By increasing the biomass concentration and lowering the inducer (isopropyl-beta-D-thiogalactoside) concentration and induction temperature, the lactonase production was significantly enhanced up to 20 kU/L, which was 20 times higher than that of wild-type strain F. proliferatum ECU2002. The recombinant Fusarium lactonase was purified using immobilized metal affinity chromatography, and its SDS-PAGE revealed a molecular mass of 50 kDa for the recombinant protein, suggesting that the enzyme was a simplex protein. Furthermore, biocatalytic properties of the recombinant lactonase were investigated, including kinetic parameters, additive's effect, and substrate specificity. The results reported in this paper provide a feasible method to make the whole cells of E. coli JM109 (DE3) expressing lactonase gene to be a highly efficient and easy-to-make biocatalyst for asymmetric synthesis of chiral compounds. PMID:19876606

  2. Peroxidase-active cell free extract from onion solid wastes: biocatalytic properties and putative pathway of ferulic acid oxidation.

    PubMed

    El Agha, Ayman; Makris, Dimitris P; Kefalas, Panagiotis

    2008-09-01

    The exploitation of food residuals can be a major contribution in reducing the polluting load of food industry waste and in developing novel added-value products. Plant food residues including trimmings and peels might contain a range of enzymes capable of transforming bioorganic molecules, and thus they may have potential uses in several biocatalytic processes, including green organic synthesis, modification of food physicochemical properties, bioremediation, etc. Although the use of bacterial and fungal enzymes has gained attention in studies pertaining to biocatalytic applications, plant enzymes have been given less consideration or even disregarded. Therefore, we investigated the use of a crude peroxidase preparation from solid onion by-products for oxidizing ferulic acid, a widespread phenolic acid, various derivatives of which may occur in food wastes. The highest enzyme activity was observed at a pH value of 4, but considerable activity was retained up to a pH value of 6. Favorable temperatures for increased activity varied between 20-40 degrees C, 30 degrees C being the optimal. Liquid chromatography-mass spectrometry analysis of a homogenate/H(2)O(2)-treated ferulic acid solution showed the formation of a dimer as a major oxidation product. PMID:18930006

  3. Branched zinc oxide nanorods arrays modified paper electrode for electrochemical immunosensing by combining biocatalytic precipitation reaction and competitive immunoassay mode.

    PubMed

    Sun, Guoqiang; Yang, Hongmei; Zhang, Yan; Yu, Jinghua; Ge, Shenguang; Yan, Mei; Song, Xianrang

    2015-12-15

    Branched zinc oxide nanorods (BZR) arrays, an array with high charge carries collection efficiency and specific surface area, are grown on the reduced graphene oxide-paper working electrode for the first time to construct a paper-based electrochemical (EC) immunosensor. Typically, the BZR are fabricated via a simple hydrothermal process, which can provide abundant sites for antibodies loading. By combining the large surface area of porous zinc oxide (PZS) and good biocompatibility of gold nanoparticles (AuNPs), PZS-AuNPs (PZS@Au) nanocomposites are designed to label horseradish peroxide (HRP) and antigens. After a competitive reaction between antigens and PZS@Au nanocomposites labeled antigens, the signal labels are introduced into the immunosensor, in which, HRP participate in biocatalytic precipitation process. The produced precipitate reduces the electrode surface area and hinders the electron transfer. With the increase of concentration of antigens, the signal labels introduced into the sensor decrease, thus, a signal-on immunoassay for α-fetoprotein detection is constructed. The proposed paper-based EC immunosensor combines enzymatic biocatalytic precipitation reaction and competitive immunoassay mode for the first time, and possesses a wide linear range from 0.2 pg mL(-1) to 500 ng mL(-1) with a detection limit of 0.08 pg mL(-1). In addition, the proposed method is simple, sensitive and specific and can be a promising platform for other protein detection. PMID:26232677

  4. 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.

  5. 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.

  6. Peroxide-mediated desulfurization of phosphorothioate oligonucleotides and its prevention.

    PubMed

    Krotz, Achim H; Mehta, Rahul C; Hardee, Gregory E

    2005-02-01

    Desulfurization at the internucleotide phosphorothioate linkage of antisense oligonucleotides (ASOs) in dermatological formulations has been investigated using strong ion exchange chromatography and mass spectroscopy. The formation of phosphate diester linkages appeared to arise from a reaction between the phosphorothioate oligonucleotide and a potent oxidizing agent. Screening of excipients used in the formulation indicated that the cause of desulfurization was related to the presence of polyethylene glycol-derived nonionic surfactants MYRJ 52 or BRIJ 58. Autoxidation of the polyethylene glycol chain is suggested as the probable origin for the observed incompatibility. The ability of various antioxidants to prevent oxidative degradation of ASO-1 in simple test systems and in oil-in-water emulsions is described. It is found that in test systems both lipophilic and hydrophilic antioxidants are effective. However, in cream formulation (oil-in-water emulsions) of ASO-1 the addition of hydrophilic antioxidants L-cysteine or DL-alpha-lipoic acid has been shown to be superior in protecting the oligonucleotide from desulfurization upon storage. PMID:15614814

  7. 1,3-Diferuloyl-sn-glycerol from the biocatalytic transesterification of ethyl 4-hydroxy-3-methoxy cinnamic acid (ethyl ferulate) and soybean oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    1,3-Diferuloyl-sn-glycerol is a natural plant component found ubiquitously throughout the plant kingdom, possessing ultraviolet adsorbing and antioxidant properties. Diferuloyl glycerol was synthesized and isolated as a byproduct in up to 5% yield from the pilot plant scale packed-bed, biocatalytic...

  8. Use of Flue Gas Desulfurization (FGD) Gypsum as a Heavy Metal Stabilizer in Contaminated Soils

    EPA Science Inventory

    Flue Gas Desulfurization (FGD) gypsum is a synthetic by-product generated from the flue gas desulfurization process in coal power plants. It has several beneficial applications such as an ingredient in cement production, wallboard production and in agricultural practice as a soil...

  9. Deep catalytic oxidative desulfurization (ODS) of dibenzothiophene (DBT) with oxalate-based deep eutectic solvents (DESs).

    PubMed

    Lü, Hongying; Li, Pengcheng; Deng, Changliang; Ren, Wanzhong; Wang, Shunan; Liu, Pan; Zhang, Han

    2015-07-01

    An oxalate-based DES with a tetrabutyl ammonium chloride and oxalate acid molar ratio of 1/2 (TBO1 : 2) exhibited high activity in oxidative desulfurization (ODS) of dibenzothiophene (DBT) under mild reaction conditions. It is potentially a promising and highly environmentally friendly approach for desulfurization of fuels. PMID:26051675

  10. Bench-scale development of mild gasification char desulfurization. Technical report, 1 December 1993--28 February 1994

    SciTech Connect

    Knight, R.A.

    1994-06-01

    The goal of this project is to scale up a process, developed under a previous ICCI grant, for desulfurization of mild gasification char by treatment with hydrogen-rich process-derived fuel gas at 650--760 C and 7-15 atm. The char can be converted into a low-sulfur metallurgical form coke. In the prior study, IBC-105 coal with 4.0 wt % sulfur was converted to chars with less than 1.0 wt% sulfur was converted to chars with less than 1.0 wt % sulfur in a laboratory-scale batch reactor. The susceptibility of the char to desulfurization was correlated with physicochemical char properties and mild gasification conditions. Acid pretreatment of the coal prior to mild gasification was also shown to significantly enhance subsequent sulfur removal. In this study, IGT is conducting continuous bench-scale tests in a 1-lb/h fluidized-bed reactor to determine the preferred process conditions and obtain steady-state data necessary for process conditions and obtain steady-state data necessary for process design and scale-up. The desulfurized chars are to be used to produce low-sulfur form coke, which will be evaluated for density, reactivity, and strength properties relevant to utilization in blast furnaces. During the second quarter, the authors completed the acid pretreatment of 25 lb (11 kg) of the 40 x 80-mesh IBC-105 coal and 7 lb (3 kg) of carbonizer char. Modifications of the bench-scale fluidized-bed reactor were completed, permitting extended-duration char-producing runs with caking coal. Char-producing runs were initiated at 1100 F and 20 psig in nitrogen, and will continue into the third quarter.