A Probabilistic Assessment of NASA Ultra-Efficient Engine Technologies for a Large Subsonic Transport

NASA Technical Reports Server (NTRS)

Tong, Michael T.; Jones, Scott M.; Arcara, Philip C., Jr.; Haller, William J.

2004-01-01

NASA's Ultra Efficient Engine Technology (UEET) program features advanced aeropropulsion technologies that include highly loaded turbomachinery, an advanced low-NOx combustor, high-temperature materials, intelligent propulsion controls, aspirated seal technology, and an advanced computational fluid dynamics (CFD) design tool to help reduce airplane drag. A probabilistic system assessment is performed to evaluate the impact of these technologies on aircraft fuel burn and NOx reductions. A 300-passenger aircraft, with two 396-kN thrust (85,000-pound) engines is chosen for the study. The results show that a large subsonic aircraft equipped with the UEET technologies has a very high probability of meeting the UEET Program goals for fuel-burn (or equivalent CO2) reduction (15% from the baseline) and LTO (landing and takeoff) NOx reductions (70% relative to the 1996 International Civil Aviation Organization rule). These results are used to provide guidance for developing a robust UEET technology portfolio, and to prioritize the most promising technologies required to achieve UEET program goals for the fuel-burn and NOx reductions.

Antioxidant (A-tocopherol acetate) effect on oxidation stability and NOx emission reduction in methyl ester of Annona oil operated diesel engine

NASA Astrophysics Data System (ADS)

Senthil, R.; Silambarasan, R.; Pranesh, G.

2017-05-01

There is a major drawback while using biodiesel as a alternate fuel for compression ignition diesel engine due to lower heating value, higher viscosity, higher density and higher oxides of nitrogen emission. To minimize these drawbacks, fuel additives can contribute towards engine performance and exhaust emission reduction either directly or indirectly. In this current work, the test was conducted to investigate the effect of antioxidant additive (A-tocopherol acetate) on oxidation stability and NOx emission in a of Annona methyl ester oil (MEAO) fueled diesel engine. The A-tocopherol acetate is mixed in different concentrations such as 0.01, 0.02, 0.03 and 0.04% with 100% by vol MEAO. It is concluded that the antioxidant additive very effective in increasing the oxidation stability and in controlling the NOx emission. Further, the addition of antioxidant additive is slight increase the HC, CO and smoke emissions. Hence, A-tocopherol acetate is very effective in controlling the NOx emission with MEAO operated diesel engine without any major modification.

Effect of reductive treatments on Pt behavior and NOx storage in lean NOx trap catalysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Xianqin; Kim, Do Heui; Kwak, Ja Hun

2011-10-01

Lean NOx trap (LNT) catalysts represent a promising approach to meet increasingly stringent NOx emission regulations on diesel and other lean-burn engines. Pt material properties, including dispersion and particle size, are known to be important factors in determining NOx uptake performance, since Pt provides active sites for NO oxidation to NO2 necessary for storing NOx as nitrates, and for the reduction of nitrates to N2. In this work, the physicochemical properties of Pt in Pt-BaO/Al2O3 LNT catalysts, such as the Pt accessible surface area and particle size, were investigated by using various tools, such as irreversible volumetric H2 chemisorption, highmore » resolution transmission electron microscopy (HRTEM), and X-ray diffraction (XRD), following successive reductive treatments at elevated temperatures. NOx uptake activities were also measured to establish a relationship between the properties of Pt and NOx storage following identical high-temperature reductive treatments. We find that the reductive treatments of Pt-BaO/Al2O3 lean NOx trap catalysts at temperatures up to 500 ºC promote a significant increase in NOx uptake explained, in part, by an induced close interaction between Pt and BaO phases in the catalyst, thus enabling facilitation of the NOx storage process.« less

High Pressure Low NOx Emissions Research: Recent Progress at NASA Glenn Research Center

NASA Technical Reports Server (NTRS)

Chi-Ming, Lee; Tacina, Kathleen M.; Wey, Changlie

2007-01-01

In collaboration with U.S. aircraft engine companies, NASA Glenn Research Center has contributed to the advancement of low emissions combustion systems. For the High Speed Research Program (HSR), a 90% reduction in nitrogen oxides (NOx) emissions (relative to the then-current state of the art) has been demonstrated in sector rig testing at General Electric Aircraft Engines (GEAE). For the Advanced Subsonic Technology Program (AST), a 50% reduction in NOx emissions relative to the 1996 International Civil Aviation Organization (ICAO) standards has been at demonstrated in sector rigs at both GEAE and Pratt & Whitney (P&W). During the Ultra Efficient Engine Technology Program (UEET), a 70% reduction in NOx emissions, relative to the 1996 ICAO standards, was achieved in sector rig testing at Glenn in the world class Advanced Subsonic Combustion Rig (ASCR) and at contractor facilities. Low NOx combustor development continues under the Fundamental Aeronautics Program. To achieve these reductions, experimental and analytical research has been conducted to advance the understanding of emissions formation in combustion processes. Lean direct injection (LDI) concept development uses advanced laser-based non-intrusive diagnostics and analytical work to complement the emissions measurements and to provide guidance for concept improvement. This paper describes emissions results from flametube tests of a 9- injection-point LDI fuel/air mixer tested at inlet pressures up to 5500 kPa. Sample results from CFD and laser diagnostics are also discussed.

NASA Glenn High Pressure Low NOx Emissions Research

NASA Technical Reports Server (NTRS)

Tacina, Kathleen M.; Wey, Changlie

2008-01-01

In collaboration with U.S. aircraft engine companies, NASA Glenn Research Center has contributed to the advancement of low emissions combustion systems. For the High Speed Research Program (HSR), a 90% reduction in nitrogen oxides (NOx) emissions (relative to the then-current state of the art) has been demonstrated in sector rig testing at General Electric Aircraft Engines (GEAE). For the Advanced Subsonic Technology Program (AST), a 50% reduction in NOx emissions relative to the 1996 International Civil Aviation Organization (ICAO) standards has been demonstrated in sector rigs at both GEAE and Pratt & Whitney (P&W). During the Ultra Efficient Engine Technology Program (UEET), a 70% reduction in NOx emissions, relative to the 1996 ICAO standards, was achieved in sector rig testing at Glenn in the world class Advanced Subsonic Combustion Rig (ASCR) and at contractor facilities. Low NOx combustor development continues under the Fundamental Aeronautics Program. To achieve these reductions, experimental and analytical research has been conducted to advance the understanding of emissions formation in combustion processes. Lean direct injection (LDI) concept development uses advanced laser-based non-intrusive diagnostics and analytical work to complement the emissions measurements and to provide guidance for concept improvement. This paper describes emissions results from flametube tests of a 9-injection-point LDI fuel/air mixer tested at inlet pressures up to 5500 kPa. Sample results from CFD and laser diagnostics are also discussed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prikhodko, Vitaly Y; Pihl, Josh A; Toops, Todd J

Ethanol is a very effective reductant of nitrogen oxides (NOX) over silver/alumina (Ag/Al2O3) catalysts in lean exhaust environment. With the widespread availability of ethanol/gasoline-blended fuel in the USA, lean gasoline engines equipped with an Ag/Al2O3 catalyst have the potential to deliver higher fuel economy than stoichiometric gasoline engines and to increase biofuel utilization while meeting exhaust emissions regulations. In this work a pre-commercial 2 wt% Ag/Al2O3 catalyst was evaluated on a 2.0-liter BMW lean burn gasoline direct injection engine for the selective catalytic reduction (SCR) of NOX with ethanol/gasoline blends. The ethanol/gasoline blends were delivered via in-pipe injection upstream ofmore » the Ag/Al2O3 catalyst with the engine operating under lean conditions. A number of engine conditions were chosen to provide a range of temperatures and space velocities for the catalyst performance evaluations. High NOX conversions were achieved with ethanol/gasoline blends containing at least 50% ethanol; however, higher C1/N ratio was needed to achieve greater than 90% NOX conversion, which also resulted in significant HC slip. Temperature and HC dosing were important in controlling selectivity to NH3 and N2O. At high temperatures, NH3 and N2O yields increased with increased HC dosing. At low temperatures, NH3 yield was very low, however, N2O levels became significant. The ability to generate NH3 under lean conditions has potential for application of a dual SCR approach (HC SCR + NH3 SCR) to reduce fuel consumption needed for NOX reduction and/or increased NOX conversion, which is discussed in this work.« less

Environmental assessment of combustion modification controls for stationary internal combustion engines. Final report Sep 78-Jul 79

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lips, H.I.; Gotterba, J.A.; Lim, K.J.

1981-07-01

The report gives results of an environmental assessment of combustion modification techniques for stationary internal combustion engines, with respect to NOx control reduction effectiveness, operational impact, thermal efficiency impact, capital and annualized operating costs, and effects on emissions of pollutants other than NOx.

An experimental investigation of the effect of temperature and space velocity on the performance of a cu-zeolite flow-through SCR and a SCR catalyst on a DPF with and without PM loading

NASA Astrophysics Data System (ADS)

Kadam, Vaibhav

The heavy-duty diesel (HDD) engines use the diesel oxidation catalyst (DOC), catalyzed particulate filter (CPF) and urea injection based selective catalytic reduction (SCR) systems in sequential combination, to meet the US EPA 2010 PM and NOx emission standards. The SCR along with a NH 3 slip control catalyst (AMOX) offer NOx reduction >90 % with NH3 slip <20 ppm. However, there is a strong desire to further improve the NOx reduction performance of such systems, to meet the California Optional Low NOx Standard implemented since 2015. Integrating SCR functionality into a diesel particulate filter (DPF), by coating the SCR catalyst on the DPF, offers potential to reduce the system cost and packaging weight/ volume. It also provides opportunity to increases the SCR volume without affecting the overall packaging, to achieve NO x reduction efficiencies >95 %. In this research, the NOx reduction and NH3 storage performance of a Cu-zeolite SCR and Cu-zeolite SCR catalyst on DPF (SCRFRTM) were experimentally investigated based on the engine experimental data at steady state conditions. The experimental data for the production-2013-SCR and the SCRFRTM were collected (with and without PM loading in the SCRFRTM) on a Cummins ISB 2013 engine, at varying inlet temperatures, space velocities, inlet NOx concentrations and NO2/NOx ratios, to evaluate the NOx reduction, NH3 storage and NH 3 slip characteristics of the SCR catalyst. The SCRFRTM was loaded with 2 and 4 g/L of PM prior to the NOx reduction tests to study the effect of PM loading on the NOx reduction and NH3 storage performance of the SCRFRTM. The experimental setup and test procedures for evaluation of NOx reduction performance of the SCRFRTM, with and without PM loading in the SCRFRTM are described. The 1-D SCR model developed at MTU was calibrated to the engine experimental data obtained from the seven NOx reduction tests conducted with the production-2013-SCR. The performance of the 1-D SCR model was validated by comparing the simulation and experimental data for NO, NO2 and NH3 concentrations at the outlet of the SCR. The NO and NO 2 concentrations were calibrated to +/-20 ppm and NH3 was calibrated to +/-20 ppm. The experimental results for the production-2013-SCR indicate that the NOx reduction of 80 - 85% can be achieved for the inlet temperatures below 250°C and above 450°C and NO x reduction of 90 - 95% can be achieved for the inlet temperatures between 300 - 350°C, at ammonia to NO2 ratio (ANR) 1.0, while the NH3 slip out of the SCR was <75 ppm. Conversely, the SCRFRTM showed 90 - 95 % NOx reduction at ANR of 1.0, while the NH3 slip out of the SCRFRTM was >50 ppm, with and without PM loading in the SCRFRTM, for the inlet temperature range of 200 - 450 °C, space velocity in the range of 13 to 48 k/hr and inlet NO 2/NOx in the range of 0.2 to 0.5. The NOx reduction in the SCRFRTM increases to >98 % at ANR 1.2. However, the NH3 slip out of the SCRFRTM increases significantly at ANR 1.2. The effect of PM loading at 2 and 4 g/L on the NOx reduction performance of the SCRFRTM was negligible below 300 °C. However, with PM loading in the SCRFRTM, the NO2 reduction decreased by 3 - 5% when compared to the clean SCRFRTM, for inlet temperature >350 °C. Experimental data were also collected by reference [1] to investigate the NO2 assisted PM oxidation in the SCRFRTM for the inlet temperature range of 260 - 370 °C, with and without urea injection and thermal oxidation of PM in the SCRFRTM for the inlet temperature range of 500 - 600 °C, without urea injection by reference [1]. The experimental data obtained from this study and [1] will be used to develop and calibrate the SCR-F model at Michigan Tech. The NH3 storage for the production-2013-SCR and the SCRFRTM (with and without PM loading) were determined from the steady state engine experimental data. The NH3 storage for the production-2013-SCR and the SCRFRTM (without PM loading) were within +/-5 gmol/m 3 of the substrate, with maximum NH3 storage of 75 - 80 gmol/m3 of the substrate, at the SCR/SCRFRTM inlet temperature of 200°C. The NH3 storage in the SCRFRTM, with 2 g/L PM loading, decreased by 30%, when compared to the NH3 storage in the SCRFRTM, without PM loading. The further increase in the PM loading in the SCRFRTM, from 2 to 4 g/L, had negligible effect on NH 3 storage.

Sustained Low Temperature NOx Reduction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zha, Yuhui

Increasing regulatory, environmental, and customer pressure in recent years led to substantial improvements in the fuel efficiency of diesel engines, including the remarkable breakthroughs demonstrated through the Super Truck program supported by the U.S. Department of Energy (DOE). On the other hand, these improvements have translated into a reduction of exhaust gas temperatures, thus further complicating the task of controlling NOx emissions, especially in low power duty cycles. The need for improved NOx conversion over these low temperature duty cycles is also observed as requirements tighten with in-use emissions testing. Sustained NOx reduction at low temperatures, especially in the 150-200oCmore » range, shares some similarities with the more commonly discussed cold-start challenge, however poses a number of additional and distinct technical problems. In this project we set a bold target of achieving and maintaining a 90% NOx conversion at the SCR catalyst inlet temperature of 150oC. The project is intended to push the boundaries of the existing technologies, while staying within the realm of realistic future practical implementation. In order to meet the resulting challenges at the levels of catalyst fundamentals, system components, and system integration, Cummins has partnered with the DOE, Johnson Matthey, and Pacific Northwest National Lab and initiated the Sustained Low-Temperature NOx Reduction program at the beginning of 2015. Through this collaboration, we are exploring catalyst formulations and catalyst architectures with enhanced catalytic activity at 150°C; opportunities to approach the desirable ratio of NO and NO2 in the SCR feed gas; options for robust low-temperature reductant delivery; and the requirements for overall system integration. The program is expected to deliver an on-engine demonstration of the technical solution and an assessment of its commercial potential. In the SAE meeting, we will share the initial performance data on engine to highlight the path to achieve 90% NOx conversion at the SCR inlet temperature of 150oC.« less

High emission reduction performance of a novel organic-inorganic composite filters containing sepiolite mineral nanofibers

PubMed Central

Wang, Fei; Zhang, Hui; Liang, Jinsheng; Tang, Qingguo; Li, Yanxia; Shang, Zengyao

2017-01-01

In this work, a new organic-inorganic composite filter was prepared. The thickness, pore size, air permeability, bursting strength and microstructure were characterized systematically, proving that coatings had regulatory effect on filters physical properties. Benefitting from the distinct coatings containing 5% sepiolite nanofibers after five times dilution, the physical properties of corresponding air filter exhibits the most favorable performance and meet the standard of air filter. When used as fuel filter, it satisfies the fuel filter standard and achieves the best performance after six times dilution. The contrast test on engine emission was taken based on auto filters coated with/without as prepared nanofibers. An obvious decrease in the emission of carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxide (NOx) can be observed after installation of composite filter on vehicles. Under the high idle condition, gasoline engine emission decreased by 8.13%, 11.35% and 44.91% for CO, HC and NOx, respectively. When tested in the low idle condition, engine emission reduced by 0.43%, 1.14% and 85.67% for CO, HC and NOx, respectively. The diesel engine emissions of CO, NOx and total amount of HC and NOx decreased by 32.26%, 3.28% and 4.66%, respectively. The results illustrate the composite installation exhibits satisfactory emission reduction effect. PMID:28252034

High emission reduction performance of a novel organic-inorganic composite filters containing sepiolite mineral nanofibers

NASA Astrophysics Data System (ADS)

Wang, Fei; Zhang, Hui; Liang, Jinsheng; Tang, Qingguo; Li, Yanxia; Shang, Zengyao

2017-03-01

In this work, a new organic-inorganic composite filter was prepared. The thickness, pore size, air permeability, bursting strength and microstructure were characterized systematically, proving that coatings had regulatory effect on filters physical properties. Benefitting from the distinct coatings containing 5% sepiolite nanofibers after five times dilution, the physical properties of corresponding air filter exhibits the most favorable performance and meet the standard of air filter. When used as fuel filter, it satisfies the fuel filter standard and achieves the best performance after six times dilution. The contrast test on engine emission was taken based on auto filters coated with/without as prepared nanofibers. An obvious decrease in the emission of carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxide (NOx) can be observed after installation of composite filter on vehicles. Under the high idle condition, gasoline engine emission decreased by 8.13%, 11.35% and 44.91% for CO, HC and NOx, respectively. When tested in the low idle condition, engine emission reduced by 0.43%, 1.14% and 85.67% for CO, HC and NOx, respectively. The diesel engine emissions of CO, NOx and total amount of HC and NOx decreased by 32.26%, 3.28% and 4.66%, respectively. The results illustrate the composite installation exhibits satisfactory emission reduction effect.

Influence of cooled exhaust gas recirculation on performance, emissions and combustion characteristics of LPG fuelled lean burn SI engine

NASA Astrophysics Data System (ADS)

Ravi, K.; Pradeep Bhasker, J.; Alexander, Jim; Porpatham, E.

2017-11-01

On fuel perspective, Liquefied Petroleum Gas (LPG) provides cleaner emissions and also facilitates lean burn signifying less fuel consumption and emissions. Lean burn technology can attain better efficiencies and lesser combustion temperatures but this temperature is quite sufficient to facilitate formation of nitrogen oxide (NOx). Exhaust Gas Recirculation (EGR) for NOx reduction has been considered allover but extremely little literatures exist on the consequence of EGR on lean burn LPG fuelled spark ignition (SI) engine. The following research is carried out to find the optimal rate of EGR addition to reduce NOx emissions without settling on performance and combustion characteristics. A single cylinder diesel engine is altered to operate as LPG fuelled SI engine at a compression ratio of 10.5:1 and arrangements to provide different ratios of cooled EGR in the intake manifold. Investigations are done to arrive at optimum ratio of the EGR to reduce emissions without compromising on performance. Significant reductions in NOx emissions alongside HC and CO emissions were seen. Higher percentages of EGR further diluted the charge and lead to improper combustion and thus increased hydrocarbon emissions. Cooled EGR reduced the peak in-cylinder temperature which reduced NOx emissions but lead to misfire at lower lean limits.

Effects of NOX Storage Component on Ammonia Formation in TWC for Passive SCR NOX Control in Lean Gasoline Engines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prikhodko, Vitaly Y.; Pihl, Josh A.; Toops, Todd J.

A prototype three-way catalyst (TWC) with NOX storage component was evaluated for ammonia (NH3) generation on a 2.0-liter BMW lean burn gasoline direct injection engine as a component in a passive ammonia selective catalytic reduction (SCR) system. The passive NH3 SCR system is a potential approach for controlling nitrogen oxides (NOX) emissions from lean burn gasoline engines. In this system, NH3 is generated over a close-coupled TWC during periodic slightly-rich engine operation and subsequently stored on an underfloor SCR catalyst. Upon switching to lean, NOX passes through the TWC and is reduced by the stored NH3 on the SCR catalyst.more » Adding a NOX storage component to a TWC provides two benefits in the context of a passive SCR system: (1) enabling longer lean operation by storing NOX upstream and preserving NH3 inventory on the downstream SCR catalyst; and (2) increasing the quantity and rate of NH3 production during rich operation. Since the fuel penalty associated with passive SCR NOX control depends on the fraction of time that the engine is running rich rather than lean, both benefits (longer lean times and shorter rich times achieved via improved NH3 production) will decrease the passive SCR fuel penalty. However, these benefits are primarily realized at low to moderate temperatures (300-500 °C), where the NOX storage component is able to store NOX, with little to no benefit at higher temperatures (>500 °C), where NOX storage is no longer effective. This study discusses engine parameters and control strategies affecting the NH3 generation over a TWC with NOX storage component.« less

Simultaneous NOx and hydrocarbon emissions control for lean-burn engines using low-temperature solid oxide fuel cell at open circuit.

PubMed

Huang, Ta-Jen; Hsu, Sheng-Hsiang; Wu, Chung-Ying

2012-02-21

The high fuel efficiency of lean-burn engines is associated with high temperature and excess oxygen during combustion and thus is associated with high-concentration NO(x) emission. This work reveals that very high concentration of NO(x) in the exhaust can be reduced and hydrocarbons (HCs) can be simultaneously oxidized using a low-temperature solid oxide fuel cell (SOFC). An SOFC unit is constructed with Ni-YSZ as the anode, YSZ as the electrolyte, and La(0.6)Sr(0.4)CoO(3) (LSC)-Ce(0.9)Gd(0.1)O(1.95) as the cathode, with or without adding vanadium to LSC. SOFC operation at 450 °C and open circuit can effectively treat NO(x) over the cathode at a very high concentration in the simulated exhaust. Higher NO(x) concentration up to 5000 ppm can result in a larger NO(x) to N(2) rate. Moreover, a higher oxygen concentration promotes NO conversion. Complete oxidation of HCs can be achieved by adding silver to the LSC current collecting layer. The SOFC-based emissions control system can treat NO(x) and HCs simultaneously, and can be operated without consuming the anode fuel (a reductant) at near the engine exhaust temperature to eliminate the need for reductant refilling and extra heating.

Model predictive control of a lean-burn gasoline engine coupled with a passive selective catalytic reduction system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Pingen; Lin, Qinghua; Prikhodko, Vitaly Y.

Lean-burn gasoline engines have demonstrated 10–20% engine efficiency gain over stoichiometric engines and are widely considered as a promising technology for meeting the 54.5 miles-per-gallon (mpg) Corporate Average Fuel Economy standard by 2025. Nevertheless, NOx emissions control for lean-burn gasoline for meeting the stringent EPA Tier 3 emission standards has been one of the main challenges towards the commercialization of highly-efficient lean-burn gasoline engines in the United States. Passive selective catalytic reduction (SCR) systems, which consist of a three-way catalyst and SCR, have demonstrated great potentials of effectively reducing NOx emissions for lean gasoline engines but may cause significant fuelmore » penalty due to ammonia generation via rich engine combustion. The purpose of this study is to develop a model-predictive control (MPC) scheme for a lean-burn gasoline engine coupled with a passive SCR system to minimize the fuel penalty associated with passive SCR operation while satisfying stringent NOx and NH3 emissions requirements. Simulation results demonstrate that the MPC-based control can reduce the fuel penalty by 47.7% in a simulated US06 cycle and 32.0% in a simulated UDDS cycle, compared to the baseline control, while achieving over 96% deNOx efficiency and less than 15 ppm tailpipe ammonia slip. The proposed MPC control can potentially enable high engine efficiency gain for highly-efficient lean-burn gasoline engine while meeting the stringent EPA Tier 3 emission standards.« less

Evaluation of the impacts of biodiesel and second generation biofuels on NO(x) emissions for CARB diesel fuels.

PubMed

Hajbabaei, Maryam; Johnson, Kent C; Okamoto, Robert A; Mitchell, Alexander; Pullman, Marcie; Durbin, Thomas D

2012-08-21

The impact of biodiesel and second generation biofuels on nitrogen oxides (NO(x)) emissions from heavy-duty engines was investigated using a California Air Resources Board (CARB) certified diesel fuel. Two heavy-duty engines, a 2006 engine with no exhaust aftertreatment, and a 2007 engine with a diesel particle filter (DPF), were tested on an engine dynamometer over four different test cycles. Emissions from soy- and animal-based biodiesels, a hydrotreated renewable diesel, and a gas to liquid (GTL) fuel were evaluated at blend levels from 5 to 100%. NO(x) emissions consistently increased with increasing biodiesel blend level, while increasing renewable diesel and GTL blends showed NO(x) emissions reductions with blend level. NO(x) increases ranged from 1.5% to 6.9% for B20, 6.4% to 18.2% for B50, and 14.1% to 47.1% for B100. The soy-biodiesel showed higher NO(x) emissions increases compared to the animal-biodiesel. NO(x) emissions neutrality with the CARB diesel was achieved by blending GTL or renewable diesel fuels with various levels of biodiesel or by using di-tert-butyl peroxide (DTBP). It appears that the impact of biodiesel on NO(x) emissions might be a more important consideration when blended with CARB diesel or similar fuels, and that some form of NO(x) mitigation might be needed for biodiesel blends with such fuels.

Selective NOx Recirculation for Stationary Lean-Burn Natural Gas Engines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nigel Clark; Gregory Thompson; Richard Atkinson

Selective NOx Recirculation (SNR) involves cooling the engine exhaust gas and then adsorbing the oxides of nitrogen (NOx) from the exhaust stream, followed by the periodic desorption of NOx. By returning the desorbed, concentrated NOx into the engine intake and through the combustion chamber, a percentage of the NOx is decomposed during the combustion process. An initial study of NOx decomposition during lean-burn combustion was concluded in 2004 using a 1993 Cummins L10G 240hp natural gas engine. It was observed that the air/fuel ratio, injected NO (nitric oxide) quantity and engine operating points affected NOx decomposition rates of the engine.more » Chemical kinetic modeling results were also used to determine optimum NOx decomposition operating points and were published in the 2004 annual report. A NOx decomposition rate of 27% was measured from this engine under lean-burn conditions while the software model predicted between 35-42% NOx decomposition for similar conditions. A later technology 1998 Cummins L10G 280hp natural gas engine was procured with the assistance of Cummins Inc. to replace the previous engine used for 2005 experimental research. The new engine was equipped with an electronic fuel management system with closed-loop control that provided a more stable air/fuel ratio control and improved the repeatability of the tests. The engine was instrumented with an in-cylinder pressure measurement system and electronic controls, and was adapted to operate over a range of air/fuel ratios. The engine was connected to a newly commissioned 300hp alternating current (AC) motoring dynamometer. The second experimental campaign was performed to acquire both stoichiometric and slightly rich (0.97 lambda ratio) burn NOx decomposition rates. Effects of engine load and speed on decomposition were quantified, but Exhaust Gas Recirculation (EGR) was not varied independently. Decomposition rates of up to 92% were demonstrated. Following recommendations at the 2004 ARES peer review meeting at Argonne National Laboratories, in-cylinder pressure was measured to calculate engine indicated mean effective pressure (IMEP) changes due to NOx injections and EGR variations, and to observe conditions in the cylinder. The third experimental campaign gathered NOx decomposition data at 800, 1200 and 1800 rpm. EGR was added via an external loop, with EGR ranging from zero to the point of misfire. The air/fuel ratio was set at both stoichiometric and slightly rich conditions, and NOx decomposition rates were calculated for each set of runs. Modifications were made to the engine exhaust manifold to record individual exhaust temperatures. The three experimental campaigns have provided the data needed for a comprehensive model of NOx decomposition during the combustion process, and data have confirmed that there was no significant impact of injected NO on in-cylinder pressure. The NOx adsorption system provided by Sorbent Technologies Corp. (Twinsburg, OH), comprised a NOx adsorber, heat exchanger and a demister. These components were connected to the engine, and data were gathered to show both the adsorption of NOx from the engine, and desorption of NOx from the carbon-based sorbent material back into the engine intake, using a heated air stream. In order to quantify the NOx adsorption/desorption characteristics of the sorbent material, a bench top adsorption system was constructed and instrumented with thermocouples and the system output was fed into a NOx analyzer. The temperature of this apparatus was controlled while gathering data on the characteristics of the sorbent material. These data were required for development of a system model. Preliminary data were gathered in 2005, and will continue in early 2006. To assess the economic benefits of the proposed SNR technology the WVU research team has been joined in the last quarter by Dr Richard Turton (WVU-Chemical Engineering), who is modeling, sizing and costing the major components. The tasks will address modeling and preliminary design of the heat exchanger, demister and NOx sorbent chamber suitable for a given engine. A simplified linear driving force model was developed to predict NOx adsorption into the sorbent material as cooled exhaust passes over fresh sorbent material. This aspect of the research will continue into 2006, and the benefits and challenges of SNR will be compared with those of competing systems, such as Selective Catalytic Reduction. Chemical kinetic modeling using the CHEMKIN software package was extended in 2005 to the case of slightly rich burn with EGR. Simulations were performed at 10%, 20%, 30% and 40% of the intake air replaced with EGR. NOx decomposition efficiency was calculated at the point in time where 98% of fuel was consumed, which is believed to be a conservative approach. The modeling data show that reductions of over 70% are possible using the ''98% fuel burned'' assumption.« less

NOx Emissions Performance and Correlation Equations for a Multipoint LDI Injector

NASA Technical Reports Server (NTRS)

He, Zhuohui J.; Chang, Clarence T.; Follen, Caitlin E.

2014-01-01

Lean Direct Injection (LDI) is a combustor concept that reduces nitrogen oxides (NOx) emissions. This paper looks at a 3-zone multipoint LDI concept developed by Parker Hannifin Corporation. The concept was tested in a flame-tube test facility at NASA Glenn Research Center. Due to test facility limitations, such as inlet air temperature and pressure, the flame-tube test was not able to cover the full set of engine operation conditions. Three NOx correlation equations were developed based on assessing NOx emissions dependencies on inlet air pressure (P3), inlet air temperature (T3), and fuel air equivalence ratio (phi) to estimate the NOx emissions at the unreachable high engine power conditions. As the results, the NOx emissions are found to be a strong function of combustion inlet air temperature and fuel air equivalence ratio but a weaker function of inlet air pressure. With these three equations, the NOx emissions performance of this injector concept is calculated as a 66 percent reduction relative to the ICAO CAEP-6 standard using a 55:1 pressure-ratio engine cycle. Uncertainty in the NOx emissions estimation increases as the extrapolation range departs from the experimental conditions. Since maximum inlet air pressure tested was less than 50 percent of the full power engine inlet air pressure, a future experiment at higher inlet air pressure conditions is needed to confirm the NOx emissions dependency on inlet air pressure.

NOx Emissions Performance and Correlation Equations for a Multipoint LDI Injector

NASA Technical Reports Server (NTRS)

He, Zhuohui Joe; Chang, Clarence T.; Follen, Caitlin E.

2015-01-01

Lean Direct Injection (LDI) is a combustor concept that reduces nitrogen oxides (NOx) emissions.This paper looks at a 3-zone multipoint LDI concept developed by Parker Hannifin Corporation. The concept was tested in a flame-tube test facility at NASA Glenn Research Center. Due to test facility limitations, such as inlet air temperature and pressure, the flame-tube test was not able to cover the full set of engine operation conditions. Three NOx correlation equations were developed based on assessing NOx emissions dependencies on inlet air pressure (P3), inlet air temperature (T3), and fuel air equivalence ratio(theta) to estimate the NOx emissions at the unreachable high engine power conditions. As the results, the NOx emissions are found to be a strong function of combustion inlet air temperature and fuel air equivalence ratio but a weaker function of inlet air pressure. With these three equations, the NOx emissions performance of this injector concept is calculated as a 66 reduction relative to the ICAO CAEP-6 standard using a 55:1 pressure-ratio engine cycle. Uncertainty in the NOx emissions estimation increases as the extrapolation range departs from the experimental conditions. Since maximum inlet air pressure tested was less than 50 of the full power engine inlet air pressure, a future experiment at higher inlet air pressure conditions is needed to confirm the NOx emissions dependency on inlet air pressure.

NOx Emissions Performance and Correlation Equations for a Multipoint LDI Injector

NASA Technical Reports Server (NTRS)

He, Zhuohui J.; Chang, Clarence T.; Follen, Caitlin E.

2015-01-01

Lean Direct Injection (LDI) is a combustor concept that reduces nitrogen oxides (NOx) emissions. This paper looks at a 3-zone multipoint LDI concept developed by Parker Hannifin Corporation. The concept was tested in a flame-tube test facility at NASA Glenn Research Center. Due to test facility limitations, such as inlet air temperature and pressure, the flame-tube test was not able to cover the full set of engine operation conditions. Three NOx correlation equations were developed based on assessing NOx emissions dependencies on inlet air pressure (P3), inlet air temperature (T3), and fuel air equivalence ratio (?) to estimate the NOx emissions at the unreachable high engine power conditions. As the results, the NOx emissions are found to be a strong function of combustion inlet air temperature and fuel air equivalence ratio but a weaker function of inlet air pressure. With these three equations, the NOx emissions performance of this injector concept is calculated as a 66% reduction relative to the ICAO CAEP-6 standard using a 55:1 pressure-ratio engine cycle. Uncertainty in the NOx emissions estimation increases as the extrapolation range departs from the experimental conditions. Since maximum inlet air pressure tested was less than 50% of the full power engine inlet air pressure, a future experiment at higher inlet air pressure conditions is needed to confirm the NOx emissions dependency on inlet air pressure.

NOx Emissions Performance and Correlation Equations for a Multipoint LDI Injector

NASA Technical Reports Server (NTRS)

He, Zhuohui J.; Chang, Clarence T.; Follen, Caitlin E.

2014-01-01

Lean Direct Injection (LDI) is a combustor concept that reduces nitrogen oxides (NOx) emissions. This paper looks at a 3-zone multipoint LDI concept developed by Parker Hannifin Corporation. The concept was tested in a flame-tube test facility at NASA Glenn Research Center. Due to test facility limitations, such as inlet air temperature and pressure, the flame-tube test was not able to cover the full set of engine operation conditions. Three NOx correlation equations were developed based on assessing NOx emissions dependencies on inlet air pressure (P3), inlet air temperature (T3), and fuel air equivalence ratio (?) to estimate the NOx emissions at the unreachable high engine power conditions. As the results, the NOx emissions are found to be a strong function of combustion inlet air temperature and fuel air equivalence ratio but a weaker function of inlet air pressure. With these three equations, the NOx emissions performance of this injector concept is calculated as a 66 percent reduction relative to the ICAO CAEP-6 standard using a 55:1 pressure-ratio engine cycle. Uncertainty in the NOx emissions estimation increases as the extrapolation range departs from the experimental conditions. Since maximum inlet air pressure tested was less than 50 percent of the full power engine inlet air pressure, a future experiment at higher inlet air pressure conditions is needed to confirm the NOx emissions dependency on inlet air pressure.

Discovery of Novel NOx Catalysts for CIDI Applications by High-throughput Methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blint, Richard J.

DOE project DE-PS26-00NT40758 has developed very active, lean exhaust, NOx reduction catalysts that have been tested on the discovery system, laboratory reactors and engine dynamometer systems. The goal of this project is the development of effective, affordable NOx reduction catalysts for lean combustion engines in the US light duty vehicle market which can meet Tier II emission standards with hydrocarbons based reductants for reducing NOx. General Motors (prime contractor) along with subcontractors BASF (Engelhard) (a catalytic converter developer) and ACCELRYS (an informatics supplier) carried out this project which began in August of 2002. BASF (Engelhard) has run over 16,000 testsmore » of 6100 possible catalytic materials on a high throughput discovery system suitable for automotive catalytic materials. Accelrys developed a new database informatics system which allowed material tracking and data mining. A program catalyst was identified and evaluated at all levels of the program. Dynamometer evaluations of the program catalyst both with and without additives show 92% NOx conversions on the HWFET, 76% on the US06, 60% on the cold FTP and 65% on the Set 13 heavy duty test using diesel fuel. Conversions of over 92% on the heavy duty FTP using ethanol as a second fluid reductant have been measured. These can be competitive with both of the alternative lean NOx reduction technologies presently in the market. Conversions of about 80% were measured on the EUDC for lean gasoline applications without using active dosing to adjust the C:N ratio for optimum NOx reduction at all points in the certification cycle. A feasibility analysis has been completed and demonstrates the advantages and disadvantages of the technology using these materials compared with other potential technologies. The teaming agreements among the partners contain no obstacles to commercialization of new technologies to any potential catalyst customers.« less

Lean mixture engine testing and evaluation program. [for automobile engine pollution and fuel performances

NASA Technical Reports Server (NTRS)

Dowdy, M. W.; Hoehn, F. W.; Griffin, D. C.

1975-01-01

Experimental results for fuel consumption and emissions are presented for a 350 CID (5.7 liter) Chevrolet V-8 engine modified for lean operation with gasoline. The lean burn engine achieved peak thermal efficiency at an equivalence ratio of 0.75 and a spark advance of 60 deg BTDC. At this condition the lean burn engine demonstrated a 10% reduction in brake specific fuel consumption compared with the stock engine; however, NOx and hydrocarbon emissions were higher. With the use of spark retard and/or slightly lower equivalence ratios, the NOx emissions performance of the stock engine was matched while showing a 6% reduction in brake specific fuel consumption. Hydrocarbon emissions exceeded the stock values in all cases. Diagnostic data indicate that lean performance in the engine configuration tested is limited by ignition delay, cycle-to-cycle pressure variations, and cylinder-to-cylinder distribution.

Criteria pollutant and greenhouse gas emissions from CNG transit buses equipped with three-way catalysts compared to lean-burn engines and oxidation catalyst technologies.

PubMed

Yoon, Seungju; Collins, John; Thiruvengadam, Arvind; Gautam, Mridul; Herner, Jorn; Ayala, Alberto

2013-08-01

Engine and exhaust control technologies applied to compressed natural gas (CNG) transit buses have advanced from lean-burn, to lean-burn with oxidation catalyst (OxC), to stoichiometric combustion with three-way catalyst (TWC). With this technology advancement, regulated gaseous and particulate matter emissions have been significantly reduced. Two CNG transit buses equipped with stoichiometric combustion engines and TWCs were tested on a chassis dynamometer, and their emissions were measured. Emissions from the stoichiometric engines with TWCs were then compared to the emissions from lean-burn CNG transit buses tested in previous studies. Stoichiometric combustion with TWC was effective in reducing emissions of oxides of nitrogen (NO(x)), particulate matter (PM), and nonmethane hydrocarbon (NMHC) by 87% to 98% depending on pollutants and test cycles, compared to lean combustion. The high removal efficiencies exceeded the emission reduction required from the certification standards, especially for NO(x) and PM. While the certification standards require 95% and 90% reductions for NO(x) and PM, respectively, from the engine model years 1998-2003 to the engine model year 2007, the measured NO(x) and PM emissions show 96% and 95% reductions, respectively, from the lean-burn engines to the stoichiometric engines with TWC over the transient Urban Dynamometer Driving Schedule (UDDS) cycle. One drawback of stoichiometric combustion with TWC is that this technology produces higher carbon monoxide (CO) emissions than lean combustion. In regard to controlling CO emissions, lean combustion with OxC is more effective than stoichiometric combustion. Stoichiometric combustion with TWC produced higher greenhouse gas (GHG) emissions including carbon dioxide (CO2) and methane (CH4) than lean combustion during the UDDS cycle, but lower GHG emissions during the steady-state cruise cycle. Stoichiometric combustion with three-way catalyst is currently the best emission control technology available for compressed natural gas (CNG) transit buses to meet the stringent U.S. Environmental Protection Agency (EPA) 2010 heavy-duty engine NO(x) emissions standard. For existing lean-burn CNG transit buses in the fleet, oxidation catalyst would be the most effective retrofit technology for the control of NMHC and CO emissions.

CRADA Final Report for CRADA Number ORNL00-0605: Advanced Engine/Aftertreatment System R&D

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pihl, Josh A; West, Brian H; Toops, Todd J

2011-10-01

Navistar and ORNL established this CRADA to develop diesel engine aftertreatment configurations and control strategies that could meet emissions regulations while maintaining or improving vehicle efficiency. The early years of the project focused on reducing the fuel penalty associated with lean NOx trap (LNT), also known as NOx adsorber catalyst regeneration and desulfation. While Navistar pursued engine-based (in-cylinder) approaches to LNT regeneration, complementary experiments at ORNL focused on in-exhaust fuel injection. ORNL developed a PC-based controller for transient electronic control of EGR valve position, intake throttle position, and actuation of fuel injectors in the exhaust system of a Navistar enginemore » installed at Oak Ridge. Aftertreatment systems consisting of different diesel oxidation catalysts (DOCs) in conjunction with a diesel particle filter and LNT were evaluated under quasi-steady-state conditions. Hydrocarbon (HC) species were measured at multiple locations in the exhaust system with Gas chromatograph mass spectrometry (GC-MS) and Fourier transform infrared (FTIR) spectroscopy. Under full-load, rated speed conditions, injection of fuel upstream of the DOC reduced the fuel penalty for a given level of NOx reduction by 10-20%. GC-MS showed that fuel compounds were 'cracked' into smaller hydrocarbon species over the DOC, particularly light alkenes. GC-MS analysis of HC species entering and exiting the LNT showed high utilization of light alkenes, followed by mono-aromatics; branched alkanes passed through the LNT largely unreacted. Follow-on experiments at a 'road load' condition were conducted, revealing that the NOx reduction was better without the DOC at lower temperatures. The improved performance was attributed to the large swings in the NOx adsorber core temperature. Split-injection experiments were conducted with ultra-low sulfur diesel fuel and three pure HC compounds: 1-pentene, toluene, and iso-octane. The pure compound experiments confirmed the previous results regarding hydrocarbon reactivity: 1-pentene was the most efficient LNT reductant, followed by toluene. Injection location had minimal impact on the reactivity of these two compounds. Iso-octane was an ineffective LNT reductant, requiring high doses (resulting in high HC emissions) to achieve reasonable NOx conversions. Diesel fuel reactivity was sensitive to injection location, with the best performance achieved through fuel injection downstream of the DOC. This configuration generated large LNT temperature excursions, which probably improved the efficiency of the NOx storage/reduction process, but also resulted in very high HC emissions. The ORNL team demonstrated an LNT desulfation under 'road load' conditions using throttling, EGR, and in-pipe injection of diesel fuel. Flow reactor characterization of core samples cut from the front and rear of the engine-aged LNT revealed complex spatially dependent degradation mechanisms. The front of the catalyst contained residual sulfates, which impacted NOx storage and conversion efficiencies at high temperatures. The rear of the catalyst showed significant sintering of the washcoat and precious metal particles, resulting in lower NOx conversion efficiencies at low temperatures. Further flow reactor characterization of engine-aged LNT core samples established that low temperature performance was limited by slow release and reduction of stored NOx during regeneration. Carbon monoxide was only effective at regenerating the LNT at temperatures above 200 C; propene was unreactive even at 250 C. Low temperature operation also resulted in unselective NOx reduction, resulting in high emissions of both N{sub 2}O and NH{sub 3}. During the latter years of the CRADA, the focus was shifted from LNTs to other aftertreatment devices. Two years of the CRADA were spent developing detailed ammonia SCR device models with sufficient accuracy and computational efficiency to be used in development of model-based ammonia injection control algorithms.ORNL, working closely with partners at Navistar and Mi« less

Environmental effect of antioxidant additives on exhaust emission reduction in compression ignition engine fuelled with Annona methyl ester.

PubMed

Senthil, R; Silambarasan, R

2015-01-01

The aim of the present study is to analyse the effect of antioxidant l-ascorbic acid on engine performance and emissions of a diesel engine fuelled with methyl ester of Annona oil (MEAO). The antioxidant is mixed in various concentrations (100-400 mg) with MEAO. Result shows that the antioxidant additive mixture (MEAO+LA200) is effective in control of nitrogen oxides (NOx) and hydrocarbon (HC) emission of MEAO-fuelled engine without doing any engine modification. In this study by using MEAO, the NOx emission is reduced by about 23.38% at full load while compared with neat diesel fuel. Likewise there is a reduction in carbon monoxide, smoke, and HC by about 48%, 28.57% and 29.71% at full load condition compared with neat diesel fuel.

Emissions characteristics of a diesel engine operating on biodiesel and biodiesel blended with ethanol and methanol.

PubMed

Zhu, Lei; Cheung, C S; Zhang, W G; Huang, Zhen

2010-01-15

Euro V diesel fuel, pure biodiesel and biodiesel blended with 5%, 10% and 15% of ethanol or methanol were tested on a 4-cylinder naturally-aspirated direct-injection diesel engine. Experiments were conducted under five engine loads at a steady speed of 1800 r/min. The study aims to investigate the effects of the blended fuels on reducing NO(x) and particulate. On the whole, compared with Euro V diesel fuel, the blended fuels could lead to reduction of both NO(x) and PM of a diesel engine, with the biodiesel-methanol blends being more effective than the biodiesel-ethanol blends. The effectiveness of NO(x) and particulate reductions is more effective with increase of alcohol in the blends. With high percentage of alcohol in the blends, the HC, CO emissions could increase and the brake thermal efficiency might be slightly reduced but the use of 5% blends could reduce the HC and CO emissions as well. With the diesel oxidation catalyst (DOC), the HC, CO and particulate emissions can be further reduced. Copyright 2009 Elsevier B.V. All rights reserved.

Emission reduction potential of using gas-to-liquid and dimethyl ether fuels on a turbocharged diesel engine.

PubMed

Xinling, Li; Zhen, Huang

2009-03-15

A study of engine performance characteristics and both of regulated (CO, HC, NO(x), and smoke) and unregulated (ultrafine particle number, mass concentrations and size distribution) emissions for a turbocharged diesel engine fueled with conventional diesel, gas-to-liquid (GTL) and dimethyl ether (DME) fuels respectively at different engine loads and speeds have been carried out. The results indicated that fuel components significantly affected the engine performance and regulated/unregulated emissions. GTL exhibited almost the same power and torque output as diesel, while improved fuel economy. GTL significantly reduced regulated emissions with average reductions of 21.2% in CO, 15.7% in HC, 15.6% in NO(x) and 22.1% in smoke in comparison to diesel, as well as average reductions in unregulated emissions of total ultrafine particle number (N(tot)) and mass (M(tot)) emissions by 85.3% and 43.9%. DME can significantly increase torque and power, compared with the original diesel engine, as well as significantly reduced regulated emissions of 40.1% in HC, 48.2% in NO(x) and smoke free throughout all the engine conditions. However, N(tot) for DME is close to that for diesel. The reason is that the accumulation mode particle number emissions for DME are very low due to the characteristics of oxygen content and no C-C bond, which promotes the processes of nucleation and condensation of the semi-volatile compounds in the exhaust gas, as a result, a lot of nucleation mode particles produce.

Lean NOx catalysis for gasoline fueled European cars

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1997-02-01

There is increasing interest in operating gasoline fueled passenger cars lean of the stoichiometric air/fuel (A/F) ratio to improve fuel economy. These types of engines will operate at lean A/F ratios while cruising at partial load, and return to stoichiometric or even rich conditions when more power is required. The challenge for the engine and catalyst manufacturer is to develop a system which will combine the high activity rates of a state-of-the-art three-way catalyst (TWC) with the ability to reduce nitrogen oxides (NOx) in the presence of excess oxygen. The objective is to achieve the future legislative limits (EURO III/IV)more » in the European Union. Recent developments in automotive pollution control catalysis show that the use of NOx adsorption materials is a suitable way to reduce NOx emissions of gasoline-fueled lean-burn engines. However, the primary task for the implementation of this technology in the European market will be to improve the catalyst`s high-temperature stability and to decrease its susceptibility to sulfur poisoning. Outlined here are results of a recent R and D program to achieve NOx reduction under lean-burn gasoline engine conditions. Model gas test results as well as engine bench data are used for discussion of the parameters which control NOx adsorption efficiency under various conditions.« less

Selective NOx Recirculation for Stationary Lean-Burn Natural Gas Engines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nigel N. Clark

Nitric oxide (NO) and nitrogen dioxide (NO2) generated by internal combustion (IC) engines are implicated in adverse environmental and health effects. Even though lean-burn natural gas engines have traditionally emitted lower oxides of nitrogen (NOx) emissions compared to their diesel counterparts, natural gas engines are being further challenged to reduce NOx emissions to 0.1 g/bhp-hr. The Selective NOx Recirculation (SNR) approach for NOx reduction involves cooling the engine exhaust gas and then adsorbing the NOx from the exhaust stream, followed by the periodic desorption of NOx. By sending the desorbed NOx back into the intake and through the engine, amore » percentage of the NOx can be decomposed during the combustion process. SNR technology has the support of the Department of Energy (DOE), under the Advanced Reciprocating Engine Systems (ARES) program to reduce NOx emissions to under 0.1 g/bhp-hr from stationary natural gas engines by 2010. The NO decomposition phenomenon was studied using two Cummins L10G natural gas fueled spark-ignited (SI) engines in three experimental campaigns. It was observed that the air/fuel ratio ({lambda}), injected NO quantity, added exhaust gas recirculation (EGR) percentage, and engine operating points affected NOx decomposition rates within the engine. Chemical kinetic model predictions using the software package CHEMKIN were performed to relate the experimental data with established rate and equilibrium models. The model was used to predict NO decomposition during lean-burn, stoichiometric burn, and slightly rich-burn cases with added EGR. NOx decomposition rates were estimated from the model to be from 35 to 42% for the lean-burn cases and from 50 to 70% for the rich-burn cases. The modeling results provided an insight as to how to maximize NOx decomposition rates for the experimental engine. Results from this experiment along with chemical kinetic modeling solutions prompted the investigation of rich-burn operating conditions, with added EGR to prevent preignition. It was observed that the relative air/fuel ratio, injected NO quantity, added EGR fraction, and engine operating points affected the NO decomposition rates. While operating under these modified conditions, the highest NO decomposition rate of 92% was observed. In-cylinder pressure data gathered during the experiments showed minimum deviation from peak pressure as a result of NO injections into the engine. A NOx adsorption system, from Sorbent Technologies, Inc., was integrated with the Cummins engine, comprised a NOx adsorbent chamber, heat exchanger, demister, and a hot air blower. Data were gathered to show the possibility of NOx adsorption from the engine exhaust, and desorption of NOx from the sorbent material. In order to quantify the NOx adsorption/desorption characteristics of the sorbent material, a benchtop adsorption system was constructed. The temperature of this apparatus was controlled while data were gathered on the characteristics of the sorbent material for development of a system model. A simplified linear driving force model was developed to predict NOx adsorption into the sorbent material as cooled exhaust passed over fresh sorbent material. A mass heat transfer analysis was conducted to analyze the possibility of using hot exhaust gas for the desorption process. It was found in the adsorption studies, and through literature review, that NO adsorption was poor when the carrier gas was nitrogen, but that NO in the presence of oxygen was adsorbed at levels exceeding 1% by mass of the sorbent. From the three experimental campaigns, chemical kinetic modeling analysis, and the scaled benchtop NOx adsorption system, an overall SNR system model was developed. An economic analysis was completed, and showed that the system was impractical in cost for small engines, but that economies of scale favored the technology.« less

THE EFFECT OF SULFUR ON METHANE PARTIAL OXIDATION AND REFORMING PROCESSES FOR LEAN NOX TRAP CATALYSIS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parks, II, James E; Ponnusamy, Senthil

2006-01-01

Lean NOx trap catalysis has demonstrated the ability to reduce NOx emissions from lean natural gas reciprocating engines by >90%. The technology operates in a cyclic fashion where NOx is trapped on the catalyst during lean operation and released and reduced to N2 under rich exhaust conditions; the rich cleansing operation of the cycle is referred to as "regeneration" since the catalyst is reactivated for more NOx trapping after NOx purge. Creating the rich exhaust conditions for regeneration can be accomplished by catalytic partial oxidation of methane in the exhaust system. Furthermore, catalytic reforming of partial oxidation exhaust can enablemore » increased quantities of H2 which is an excellent reductant for lean NOx trap regeneration. It is critical to maintain clean and efficient partial oxidation and reforming processes to keep the lean NOx trap functioning properly and to reduce extra fuel consumption from the regeneration process. Although most exhaust constituents do not impede partial oxidation and reforming, some exhaust constituents may negatively affect the catalysts and result in loss of catalytic efficiency. Of particular concern are common catalyst poisons sulfur, zinc, and phosphorous. These poisons form in the exhaust through combustion of fuel and oil, and although they are present at low concentrations, they can accumulate to significant levels over the life of an engine system. In the work presented here, the effects of sulfur on the partial oxidation and reforming catalytic processes were studied to determine any durability limitations on the production of reductants for lean NOx trap catalyst regeneration.« less

Investigation of NO(x) Removal from Small Engine Exhaust

NASA Technical Reports Server (NTRS)

Akyurtlu, Ates; Akyurtlu, Jale F.

1999-01-01

Contribution of emissions from small engines to the air pollution is significant. Due to differences in operating conditions and economics, the pollution control systems designed for automobiles will be neither suitable nor economically feasible for use on small engines. The objective of this project was to find a catalyst for the removal of NOx from the exhaust of small engines which use a rich air to fuel ratio. The desired catalyst should be inexpensive so that the cost of the pollution control unit will be only a small fraction of the total equipment cost. The high cost of noble metals makes them too expensive for use as NOx catalyst for small engines. Catalytic reduction of NO can also be accomplished by base-metal oxide catalysts. The main disadvantage of base-metal catalysts is their deactivation by poisons and high temperatures. Requirements for the length of the life of the small engine exhaust catalysts are much less than those for automobile exhaust catalysts. Since there is no oxygen in the exhaust gases, reduction selectivity is not a problem. Also, the reducing exhaust gases might help prevent the harmful interactions of the catalyst with the support. For these reasons only the supported metal oxide catalysts were investigated in this project.

Investigation of NOx Removal from Small Engine Exhaust

NASA Technical Reports Server (NTRS)

Akyurtlu, Ates; Akyurtlu, Jale F.

1999-01-01

Contribution of emissions from small engines to the air pollution is significant. Due to differences in operating conditions and economics, the pollution control systems designed for automobiles will be neither suitable nor economically feasible for use on small engines. The objective of this project was to find a catalyst for the removal of NOx from the exhaust of small engines which use a rich air to fuel ratio. The desired catalyst should be inexpensive so that the cost of the pollution control unit will be only a small fraction of the total equipment cost. The high cost of noble metals makes them too expensive for use as NOx catalyst for small engines. Catalytic reduction of Nitrogen Oxide (NO) can also be accomplished by base-metal oxide catalysts. The main disadvantage of base-metal catalysts is their deactivation by poisons and high temperatures. Requirements for the length of the life of the small engine exhaust catalysts are much less than those for automobile exhaust catalysts. Since there is no oxygen in the exhaust gases, reduction selectivity is not a problem. Also, the reducing exhaust gases might help prevent the harmful interactions of the catalyst with the support. For these reasons only the supported metal oxide catalysts were investigated in this project.

Lean NOx Trap Catalysis for Lean Natural Gas Engine Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parks, II, James E; Storey, John Morse; Theiss, Timothy J

Distributed energy is an approach for meeting energy needs that has several advantages. Distributed energy improves energy security during natural disasters or terrorist actions, improves transmission grid reliability by reducing grid load, and enhances power quality through voltage support and reactive power. In addition, distributed energy can be efficient since transmission losses are minimized. One prime mover for distributed energy is the natural gas reciprocating engine generator set. Natural gas reciprocating engines are flexible and scalable solutions for many distributed energy needs. The engines can be run continuously or occasionally as peak demand requires, and their operation and maintenance ismore » straightforward. Furthermore, system efficiencies can be maximized when natural gas reciprocating engines are combined with thermal energy recovery for cooling, heating, and power applications. Expansion of natural gas reciprocating engines for distributed energy is dependent on several factors, but two prominent factors are efficiency and emissions. Efficiencies must be high enough to enable low operating costs, and emissions must be low enough to permit significant operation hours, especially in non-attainment areas where emissions are stringently regulated. To address these issues the U.S. Department of Energy and the California Energy Commission launched research and development programs called Advanced Reciprocating Engine Systems (ARES) and Advanced Reciprocating Internal Combustion Engines (ARICE), respectively. Fuel efficiency and low emissions are two primary goals of these programs. The work presented here was funded by the ARES program and, thus, addresses the ARES 2010 goals of 50% thermal efficiency (fuel efficiency) and <0.1 g/bhp-hr emissions of oxides of nitrogen (NOx). A summary of the goals for the ARES program is given in Table 1-1. ARICE 2007 goals are 45% thermal efficiency and <0.015 g/bhp-hr NOx. Several approaches for improving the efficiency and emissions of natural gas reciprocating engines are being pursued. Approaches include: stoichiometric engine operation with exhaust gas recirculation and three-way catalysis, advanced combustion modes such as homogeneous charge compression ignition, and extension of the lean combustion limit with advanced ignition concepts and/or hydrogen mixing. The research presented here addresses the technical approach of combining efficient lean spark-ignited natural gas combustion with low emissions obtained from a lean NOx trap catalyst aftertreatment system. This approach can be applied to current lean engine technology or advanced lean engines that may result from related efforts in lean limit extension. Furthermore, the lean NOx trap technology has synergy with hydrogen-assisted lean limit extension since hydrogen is produced from natural gas during the lean NOx trap catalyst system process. The approach is also applicable to other lean engines such as diesel engines, natural gas turbines, and lean gasoline engines; other research activities have focused on those applications. Some commercialization of the technology has occurred for automotive applications (both diesel and lean gasoline engine vehicles) and natural gas turbines for stationary power. The research here specifically addresses barriers to commercialization of the technology for large lean natural gas reciprocating engines for stationary power. The report presented here is a comprehensive collection of research conducted by Oak Ridge National Laboratory (ORNL) on lean NOx trap catalysis for lean natural gas reciprocating engines. The research was performed in the Department of Energy's ARES program from 2003 to 2007 and covers several aspects of the technology. All studies were conducted at ORNL on a Cummins C8.3G+ natural gas engine chosen based on industry input to simulate large lean natural gas engines. Specific technical areas addressed by the research include: NOx reduction efficiency, partial oxidation and reforming chemistry, and the effects of sulfur poisons on the partial oxidation, reformer, and lean NOx trap catalysts. The initial work on NOx reduction efficiency demonstrated that NOx emissions <0.1 g/bhp-hr (the ARES goal) can be achieved with the lean NOx trap catalyst technology. Subsequent work focused on cost and size optimization and durability issues which addressed two specific ARES areas of interest to industry ('Cost of Power' and 'Availability, Reliability, and Maintainability', respectively). Thus, the research addressed the approach of the lean NOx trap catalyst technology toward the ARES goals as shown in Table 1-1.« less

Effect of B20 and Low Aromatic Diesel on Transit Bus NOx Emissions Over Driving Cycles with a Range of Kinetic Intensity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lammert, M. P.; McCormick, R. L.; Sindler, P.

2012-10-01

Oxides of nitrogen (NOx) emissions for transit buses for up to five different fuels and three standard transit duty cycles were compared to establish whether there is a real-world biodiesel NOx increase for transit bus duty cycles and engine calibrations. Six buses representing the majority of the current national transit fleet and including hybrid and selective catalyst reduction systems were tested on a heavy-duty chassis dynamometer with certification diesel, certification B20 blend, low aromatic (California Air Resources Board) diesel, low aromatic B20 blend, and B100 fuels over the Manhattan, Orange County and UDDS test cycles. Engine emissions certification level hadmore » the dominant effect on NOx; kinetic intensity was the secondary driving factor. The biodiesel effect on NOx emissions was not statistically significant for most buses and duty cycles for blends with certification diesel, except for a 2008 model year bus. CARB fuel had many more instances of a statistically significant effect of reducing NOx. SCR systems proved effective at reducing NOx to near the detection limit on all duty cycles and fuels, including B100. While offering a fuel economy benefit, a hybrid system significantly increased NOx emissions over a same year bus with a conventional drivetrain and the same engine.« less

Effects of After-Treatment Control Technologies on Heavy-Duty Diesel Truck Emissions

NASA Astrophysics Data System (ADS)

Preble, C.; Dallmann, T. R.; Kreisberg, N. M.; Hering, S. V.; Harley, R.; Kirchstetter, T.

2015-12-01

Diesel engines are major emitters of nitrogen oxides (NOx) and the black carbon (BC) fraction of particulate matter (PM). Diesel particle filter (DPF) and selective catalytic reduction (SCR) emission control systems that target exhaust PM and NOx have recently become standard on new heavy-duty diesel trucks (HDDT). There is concern that DPFs may increase ultrafine particle (UFP) and total particle number (PN) emissions while reducing PM mass emissions. Also, the deliberate catalytic oxidation of engine-out NO to NO2 in continuously regenerating DPFs may lead to increased tailpipe emission of NO2 and near-roadway concentrations that exceed the 1-hr national ambient air quality standard. Increased NO2 emissions can also promote formation of ozone and secondary PM. We report results from ongoing on-road studies of HDDT emissions at the Port of Oakland and the Caldecott Tunnel in California's San Francisco Bay Area. Emission factors (g pollutant per kg diesel) were linked via recorded license plates to each truck's engine model year and installed emission controls. At both sites, DPF use significantly increased the NO2/NOx emission ratio. DPFs also significantly increased NO2 emissions when installed as retrofits on older trucks with higher baseline NOx emissions. While SCR systems on new trucks effectively reduce total NOx emissions and mitigate these undesirable DPF-related NO2 emissions, they also lead to significant emission of N2O, a potent greenhouse gas. When expressed on a CO2-equivalent basis, the N2O emissions increase offsets the fuel economy gain (i.e., the CO2 emission reduction) associated with SCR use. At the Port, average NOx, BC and PN emission factors from new trucks equipped with DPF and SCR were 69 ± 15%, 92 ± 32% and 66 ± 35% lower, respectively, than modern trucks without these emission controls. In contrast, at the Tunnel, PN emissions from older trucks retrofit with DPFs were ~2 times greater than modern trucks without DPFs. The difference could be related to engine temperature, with highway operation producing greater exhaust temperatures that promote UFP nucleation. These studies indicate that DPF and SCR use can mitigate air quality and climate impacts of diesel truck emissions through reductions in BC and NOx. However, increased emissions of N2O, NO2 and PN may offset some of the benefits.

Recent advances in automotive catalysis for NOx emission control by small-pore microporous materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beale, Andrew M.; Gao, Feng; Lezcano-Gonzalez, Ines

The ever increasing demand to develop highly fuel efficient engines coincides with the need to minimize air pollution originating from the exhaust gases of internal combustion engines. Dramatically improved fuel efficiency can be achieved at air-to-fuel ratios much higher than stoichiometric. In the presence of oxygen in large excess, however, traditional three-way catalysts are unable to reduce NOx. Among the number of lean-NOx reduction technologies, selective catalytic reduction (SCR) of NOx by NH3 over Cu- and Fe-ion exchanged zeolite catalysts has been extensively studied over the past 30+ years. Despite the significant advances in developing a viable practical zeolite-based catalystmore » for lean NOx reduction, the insufficient hydrothermal stabilities of the zeolite structures considered cast doubts about their real-world applicability. During the past decade a renewed interest in zeolite-based lean NOx reduction was spurred by the discovery of the very high activity of Cu-SSZ-13 (and the isostructural Cu-SAPO-34) in the NH3 SCR of NOx. These new, small-pore zeolite-based catalysts not only exhibited very high NOx conversion and N2 selectivity, but also exhibited exceptional high hydrothermal stability at high temperatures. In this review we summarize the key discoveries of the past ~5 years that lead to the introduction of these catalysts into practical application. The review first briefly discusses the structure and preparation of the CHA structure-based zeolite catalysts, and then summarizes the key learnings of the rather extensive (but not complete) characterisation work. Then we summarize the key findings of reaction kinetics studies, and provide some mechanistic details emerging from these investigations. At the end of the review we highlight some of the issues that are still need to be addressed in automotive exhaust control catalysis. Funding A.M.B. and I.L.G. would like to thank EPSRC for funding. F.G., C.H.F.P. and J.Sz. gratefully acknowledge financial support from the US Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Program.« less

Multifuel evaluation of rich/quench/lean combustor

NASA Technical Reports Server (NTRS)

Notardonato, J. J.; Novick, A. S.; Troth, D. L.

1982-01-01

The fuel flexible combustor technology was developed for application to the Model 570-K industrial gas turbine engine. The technology, to achieve emission goals, emphasizes dry NOx reduction methods. Due to the high levels of fuel-bound nitrogen (FBN), control of NOx can be effected through a staged combustor with a rich initial combustion zone. A rich/quench/lean variable geometry combustor utilizes the technology presented to achieve low NOx from alternate fuels containing FBN. The results focus on emissions and durability for multifuel operation.

Exhaust emission control and diagnostics

DOEpatents

Mazur, Christopher John; Upadhyay, Devesh

2006-11-14

A diesel engine emission control system uses an upstream oxidation catalyst and a downstream SCR catalyst to reduce NOx in a lean exhaust gas environment. The engine and upstream oxidation catalyst are configured to provide approximately a 1:1 ratio of NO to NO2 entering the downstream catalyst. In this way, the downstream catalyst is insensitive to sulfur contamination, and also has improved overall catalyst NOx conversion efficiency. Degradation of the system is determined when the ratio provided is no longer near the desired 1:1 ratio. This condition is detected using measurements of engine operating conditions such as from a NOx sensor located downstream of the catalysts. Finally, control action to adjust an injected amount of reductant in the exhaust gas based on the actual NO to NO2 ratio upstream of the SCR catalyst and downstream of the oxidation catalyst.

Effects of Retrofitting Emission Control Systems on all In-Use Heavy Diesel Trucks

NASA Astrophysics Data System (ADS)

Millstein, D.; Harley, R. A.

2009-12-01

Diesel exhaust is now the largest source of nitrogen oxide (NOx) emissions nationally in the US, and contributes significantly to emissions of fine particulate black carbon (soot) as well. New national standards call for dramatically lower emissions of exhaust particulate matter (PM) and NOx from new diesel engines starting in 2007 and 2010, respectively. Unfortunately it will take decades for the cleaner new engines to replace those currently in service on existing heavy-duty trucks. The state of California recently adopted a rule to accelerate fleet turnover in the heavy-duty truck sector, requiring that all in-use trucks meet the new exhaust PM standards by 2014. This will entail retrofit of diesel particle filters or replacement for over a million existing diesel engines. Diesel particle filters can replace the muffler on existing trucks, and there is extensive experience with retrofit of this control equipment on public sector fleets such as diesel-powered transit buses. Nitrogen dioxide (NO2) is used as an oxidizing agent to remove carbon particles from the particle filter, to prevent it from becoming plugged. To create the needed NO2, NOx already present in engine exhaust as nitric oxide (NO) is deliberately oxidized to NO2 upstream of the particle filter using a platinum catalyst. The NO2/NOx ratio in exhaust emissions therefore increases to ~35% in comparison to much lower values (~5%) typical of older engines without particle filters. We evaluate the effects on air quality of increased use of diesel particle traps and NOx controls in southern California using the Community Multiscale Air Quality (CMAQ) model. Compared to a reference scenario without the retrofit program, we found black carbon concentrations decreased by ~20%, with small increases (4%) in ambient ozone concentrations. During summer, average NO2 concentrations decrease despite the increase in primary NO2 emissions - because total NOx emissions are reduced as part of a parallel but more gradual program to retrofit NOx control systems on in-use engines. During winter, NO2 concentrations increase by 1-2% at locations with high diesel truck traffic, and larger increases may occur if diesel trucks outfitted with particle traps do not meet the in-use NOx emission reduction requirements. Small changes to fine particulate nitrate are seen as well with increases over the Los Angeles area of 3 and 6% during the summer and fall, respectively. During the summer, but not the fall, downwind nitrate decreased by 2% east of Los Angeles near Riverside. Emissions reductions due to fleet turnover in the reference scenario (without retrofit) may be optimistic, and the air quality benefits of retrofits could therefore be understated, due to slow sales of new engines in recent years. In any case, significant changes in diesel engine emissions of NOx and PM are expected to occur over the next 5 years in California.

Selective catalytic reduction manages ships' emissions

DOE Office of Scientific and Technical Information (OSTI.GOV)

McMahon, K.R.

1994-10-01

Ships employed by USS-Posco Industries are the first seagoing vessels that use selective catalytic reduction in marine diesel engine design, resulting in a 90 percent reduction of nitrogen oxide emissions. The vessels, which deliver semifinished steel coils, or hot bands'', to the company's terminal in the San Francisco Bay area, were commissioned for $120 million by Pohang Iron and Steel Co. Ltd., one of UPI's parent companies. Installing the catalytic reduction equipment cost $12 million. As anticipated, NOx concentrations were reduced between 90 percent and 95 percent. However, achieving high mass NOx reduction proved more difficult, because exhaust gas hadmore » to be maintained within the desired temperature range.« less

REDUCTION OF EMISSIONS FROM A HIGH SPEED FERRY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thompson,G.; Gautam, M; Clark, N

2003-08-24

Emissions from marine vessels are being scrutinized as a major contributor to the total particulate matter (TPM), oxides of sulfur (SOx) and oxides of nitrogen (NOx) environmental loading. Fuel sulfur control is the key to SOx reduction. Significant reductions in the emissions from on-road vehicles have been achieved in the last decade and the emissions from these vehicles will be reduced by another order of magnitude in the next five years: these improvements have served to emphasize the need to reduce emissions from other mobile sources, including off road equipment, locomotives, and marine vessels. Diesel-powered vessels of interest include oceanmore » going vessels with low- and medium-speed engines, as well as ferries with high speed engines, as discussed below. A recent study examined the use of intake water injection (WIS) and ultra low sulfur diesel (ULSD) to reduce the emissions from a high-speed passenger ferry in southern California. One of the four Detroit Diesel 12V92 two-stroke high speed engines that power the Waverider (operated by SCX, inc.) was instrumented to collect intake airflow, fuel flow, shaft torque, and shaft speed. Engine speed and shaft torque were uniquely linked for given vessel draft and prevailing wind and sea conditions. A raw exhaust gas sampling system was utilized to measure the concentration of NOx, carbon dioxide (CO2), and oxygen (O2) and a mini dilution tunnel sampling a slipstream from the raw exhaust was used to collect TPM on 70 mm filters. The emissions data were processed to yield brake-specific mass results. The system that was employed allowed for redundant data to be collected for quality assurance and quality control. To acquire the data, the Waverider was operated at five different steady state speeds. Three modes were in the open sea off Oceanside, CA, and idle and harbor modes were also used. Data have showed that the use of ULSD along with water injection (WIS) could significantly reduce the emissions of NOx and PM while not affecting fuel consumption or engine performance compared to the baseline marine diesel. The results showed that a nominal 40% reduction in TPM was realized when switching from the marine diesel to the ULSD. A small reduction in NOx was also shown between the marine fuel and the ULSD. The implementation of the WIS showed that NOx was reduced significantly by between 11% and 17%, depending upon the operating condition. With the WIS, the TPM was reduced by a few percentage points, which was close to the confidence in measurement.« less

New insights from comprehensive on-road measurements of NOx, NO2 and NH3 from vehicle emission remote sensing in London, UK

NASA Astrophysics Data System (ADS)

Carslaw, David C.; Rhys-Tyler, Glyn

2013-12-01

In this paper we report the first direct measurements of nitrogen dioxide (NO2) in the UK using a vehicle emission remote sensing technique. Measurements of NO, NO2 and ammonia (NH3) from almost 70,000 vehicles were made spanning vehicle model years from 1985 to 2012. These measurements were carefully matched with detailed vehicle information data to understand the emission characteristics of a wide range of vehicles in a detailed way. Overall it is found that only petrol fuelled vehicles have shown an appreciable reduction in total NOx emissions over the past 15-20 years. Emissions of NOx from diesel vehicles, including those with after-treatment systems designed to reduce emissions of NOx, have not reduced over the same period of time. It is also evident that the vehicle manufacturer has a strong influence on emissions of NO2 for Euro 4/5 diesel cars and urban buses. Smaller-engined Euro 4/5 diesel cars are also shown to emit less NO2 than larger-engined vehicles. It is shown that NOx emissions from urban buses fitted with Selective Catalytic Reduction (SCR) are comparable to those using Exhaust Gas Recirculation for Euro V vehicles, while reductions in NOx of about 30% are observed for Euro IV and EEV vehicles. However, the emissions of NO2 vary widely dependent on the bus technology used. Almost all the NOx emission from Euro IV buses with SCR is in the form of NO, whereas EEV vehicles (Enhanced Environmentally friendly Vehicle) emit about 30% of the NOx as NO2. We find similarly low amounts of NO2 from trucks (3.5-12t and >12t). Finally, we show that NH3 emissions are most important for older generation catalyst-equipped petrol vehicles and SCR-equipped buses. The NH3 emissions from petrol cars have decreased by over a factor of three from the vehicles manufactured in the late 1990s compared with those manufactured in 2012. Tables of emission factors are presented for NOx, NO2 and NH3 together with uncertainties to assist the development of new emission inventories.

A Probabilistic System Analysis of Intelligent Propulsion System Technologies

NASA Technical Reports Server (NTRS)

Tong, Michael T.

2007-01-01

NASA s Intelligent Propulsion System Technology (Propulsion 21) project focuses on developing adaptive technologies that will enable commercial gas turbine engines to produce fewer emissions and less noise while increasing reliability. It features adaptive technologies that have included active tip-clearance control for turbine and compressor, active combustion control, turbine aero-thermal and flow control, and enabling technologies such as sensors which are reliable at high operating temperatures and are minimally intrusive. A probabilistic system analysis is performed to evaluate the impact of these technologies on aircraft CO2 (directly proportional to fuel burn) and LTO (landing and takeoff) NO(x) reductions. A 300-passenger aircraft, with two 396-kN thrust (85,000-pound) engines is chosen for the study. The results show that NASA s Intelligent Propulsion System technologies have the potential to significantly reduce the CO2 and NO(x) emissions. The results are used to support informed decisionmaking on the development of the intelligent propulsion system technology portfolio for CO2 and NO(x) reductions.

Evaluation of mobile source emission trends in the United States

NASA Astrophysics Data System (ADS)

Dallmann, Timothy R.; Harley, Robert A.

2010-07-01

A fuel-based approach is used to estimate exhaust emissions of nitrogen oxides (NOx) and fine particulate matter (PM2.5) from mobile sources in the United States for the years 1996-2006. Source categories considered include on-road and off-road gasoline and diesel engines. Pollutant emissions for each mobile source category were estimated by combining fuel consumption with emission factors expressed per unit of fuel burned. Over the 10-year time period that is the focus of this study, sales of gasoline and diesel fuel intended for on-road use increased by 15 and 43%, respectively. Diesel fuel use by off-road equipment increased by ˜20% over the same time period. Growth in fuel consumption offset some of the reductions in pollutant emission factors that occurred during this period. For NOx, there have been dramatic (factor of 2) decreases in emission factors for on-road gasoline engines between 1996 and 2006. In contrast, diesel NOx emission factors decreased more gradually. Exhaust PM2.5 emission factors appear to have decreased for most engine categories, but emission uncertainties are large for this pollutant. Diesel engines appear to be the dominant mobile source of both NOx and PM2.5; the diesel share of total NOx has increased over time as gasoline engine emissions have declined. Comparing fuel-based emission estimates with U.S. Environmental Protection Agency's national emission inventory led to the following conclusions: (1) total emissions of NOx and PM2.5 estimated by two different methods were similar, (2) source contributions to these totals differ significantly, with higher relative contributions coming from on-road diesel engines in this study.

Pollution reduction technology program for turboprop engines

NASA Technical Reports Server (NTRS)

Tomlinson, J. G.

1977-01-01

The reduction of CO, HC, and smoke emissions while maintaining acceptable NO(x) emissions without affecting fuel consumption, durability, maintainability, and safety was accomplished. Component combustor concept screening directed toward the demonstration of advanced combustor technology required to meet the EPA exhaust emissions standards for class P2 turboprop engines was covered. The combustion system for the Allison 501-D22A engine was used, and three combustor design concepts - reverse flow, prechamber, and staged fuel were evaluated.

Exhaust emissions reduction from diesel engine using combined Annona-Eucalyptus oil blends and antioxidant additive

NASA Astrophysics Data System (ADS)

Senthil, R.; Silambarasan, R.; Pranesh, G.

2017-03-01

The limited resources, rising petroleum prices and depletion of fossil fuel have now become a matter of great concern. Hence, there is an urgent need for researchers to find some alternate fuels which are capable of substituting partly or wholly the higher demanded conventional diesel fuel. Lot of research work has been conducted on diesel engine using biodiesel and its blends with diesel as an alternate fuel. Very few works have been done with combination of biodiesel-Eucalypts oil without neat diesel and this leads to lots of scope in this area. The aim of the present study is to analyze the performance and emission characteristics of a single cylinder, direct injection, compression ignition engine using eucalyptus oil-biodiesel as fuel. The presence of eucalyptus oil in the blend reduces the viscosity and improves the volatility of the blends. The methyl ester of Annona oil is blended with eucalypts oil in 10, 20, 30, 40 and 50 %. The performance and emission characteristics are evaluated by operating the engine at different loads. The performance characteristics such as brake thermal efficiency, brake specific fuel consumption and exhaust gas temperature are evaluated. The emission constituents measured are Carbon monoxide (CO), unburned hydrocarbons (HC), Oxides of nitrogen (NOx) and Smoke. It is found that A50-Eu50 (50 Annona + 50 % Eucalyptus oil) blend showed better performance and reduction in exhaust emissions. But, it showed a very marginal increase in NOx emission when compared to that of diesel. Therefore, in order to reduce the NOx emission, antioxidant additive (A-tocopherol acetate) is mixed with Annona-Eucalyptus oil blends in various proportions by which NOx emission is reduced. Hence, A50-Eu50 blend can be used as an alternate fuel for diesel engine without any modifications.

Status of Technological Advancements for Reducing Aircraft Gas Turbine Engine Pollutant Emissions

NASA Technical Reports Server (NTRS)

Rudey, R. A.

1975-01-01

Combustor test rig results indicate that substantial reductions from current emission levels of carbon monoxide (CO), total unburned hydrocarbons (THC), oxides of nitrogen (NOx), and smoke are achievable by employing varying degrees of technological advancements in combustion systems. Minor to moderate modifications to existing conventional combustors produced significant reductions in CO and THC emissions at engine low power (idle/taxi) operating conditions but did not effectively reduce NOx at engine full power (takeoff) operating conditions. Staged combusiton techniques were needed to simultaneously reduce the levels of all the emissions over the entire engine operating range (from idle to takeoff). Emission levels that approached or were below the requirements of the 1979 EPA standards were achieved with the staged combustion systems and in some cases with the minor to moderate modifications to existing conventional combustion systems. Results from research programs indicate that an entire new generation of combustor technology with extremely low emission levels may be possible in the future.

Onboard Plasmatron Hydrogen Production for Improved Vehicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daniel R. Cohn; Leslie Bromberg; Kamal Hadidi

2005-12-31

A plasmatron fuel reformer has been developed for onboard hydrogen generation for vehicular applications. These applications include hydrogen addition to spark-ignition internal combustion engines, NOx trap and diesel particulate filter (DPF) regeneration, and emissions reduction from spark ignition internal combustion engines First, a thermal plasmatron fuel reformer was developed. This plasmatron used an electric arc with relatively high power to reform fuels such as gasoline, diesel and biofuels at an oxygen to carbon ratio close to 1. The draw back of this device was that it has a high electric consumption and limited electrode lifetime due to the high temperaturemore » electric arc. A second generation plasmatron fuel reformer was developed. It used a low-current high-voltage electric discharge with a completely new electrode continuation. This design uses two cylindrical electrodes with a rotating discharge that produced low temperature volumetric cold plasma., The lifetime of the electrodes was no longer an issue and the device was tested on several fuels such as gasoline, diesel, and biofuels at different flow rates and different oxygen to carbon ratios. Hydrogen concentration and yields were measured for both the thermal and non-thermal plasmatron reformers for homogeneous (non-catalytic) and catalytic reforming of several fuels. The technology was licensed to an industrial auto part supplier (ArvinMeritor) and is being implemented for some of the applications listed above. The Plasmatron reformer has been successfully tested on a bus for NOx trap regeneration. The successful development of the plasmatron reformer and its implementation in commercial applications including transportation will bring several benefits to the nation. These benefits include the reduction of NOx emissions, improving engine efficiency and reducing the nation's oil consumption. The objective of this program has been to develop attractive applications of plasmatron fuel reformer technology for onboard applications in internal combustion engine vehicles using diesel, gasoline and biofuels. This included the reduction of NOx and particulate matter emissions from diesel engines using plasmatron reformer generated hydrogen-rich gas, conversion of ethanol and bio-oils into hydrogen rich gas, and the development of new concepts for the use of plasmatron fuel reformers for enablement of HCCI engines.« less

SCR SYSTEMS FOR HEAVY DUTY TRUCKS: PROGRESS TOWARDS MEETING EURO 4 EMISSION STANDARDS IN 2005

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frank, W; Huethwohl, G; Maurer, B

2003-08-24

Emissions of diesel engines contain some components, which support the generation of smog and which are classified hazardous. Exhaust gas aftertreatment is a powerful tool to reduce the NOx and Particulate emissions. The NOx-emission can be reduced by the SCR technology. SCR stands for Selective Catalytic Reduction. A reduction agent has to be injected into the exhaust upstream of a catalyst. On the catalyst the NOx is reduced to N2 (Nitrogen) and H2O (Water). This catalytic process was developed in Japan about 30 years ago to reduce the NOx emission of coal-fired power plants. The first reduction agent used wasmore » anhydrous ammonia (NH3). SCR technology was used with diesel engines starting mid of the 80s. First applications were stationary operating generator-sets. In 1991 a joint development between DaimlerChrysler, MAN, IVECO and Siemens was started to use SCR technology for the reduction of heavy duty trucks. Several fleet tests demonstrated the durability of the systems. To day, SCR technology is the most promising technology to fulfill the new European Regulations EURO 4 and EURO 5 being effective Oct. 2005 and Oct. 2008. The efficient NOx reduction of the catalyst allows an engine calibration for low fuel consumption. DaimlerChrysler decided to use the SCR technology on every heavy duty truck and bus in Europe and many other truck manufacturers will introduce SCR technology to fulfill the 2005 emission regulation. The truck manufacturers in Europe agreed to use aqueous solution of Urea as reducing agent. The product is called AdBlue. AdBlue is a non toxic, non smelling liquid. The consumption is about 5% of the diesel fuel consumption to reduce the NOx emissions. A small AdBlue tank has to be installed to the vehicle. With an electronically controlled dosing system the AdBlue is injected into the exhaust. The dosing system is simple and durable. It has proven its durability during winter and summer testing as well as in fleet tests. The infrastructure for AdBlue is under evaluation in Europe by Urea Producers and Mineral Oil companies to be readily available in time. Urea is one of the most common chemical products in the world and the production and the distribution very much experienced. However, a pure grade is needed for automotive application and requires special attention.« less

Application of Boiler Op for combustion optimization at PEPCO

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maines, P.; Williams, S.; Levy, E.

1997-09-01

Title IV requires the reduction of NOx at all stations within the PEPCO system. To assist PEPCO plant personnel in achieving low heat rates while meeting NOx targets, Lehigh University`s Energy Research Center and PEPCO developed a new combustion optimization software package called Boiler Op. The Boiler Op code contains an expert system, neural networks and an optimization algorithm. The expert system guides the plant engineer through a series of parametric boiler tests, required for the development of a comprehensive boiler database. The data are then analyzed by the neural networks and optimization algorithm to provide results on the boilermore » control settings which result in the best possible heat rate at a target NOx level or produce minimum NOx. Boiler Op has been used at both Potomac River and Morgantown Stations to help PEPCO engineers optimize combustion. With the use of Boiler Op, Morgantown Station operates under low NOx restrictions and continues to achieve record heat rate values, similar to pre-retrofit conditions. Potomac River Station achieves the regulatory NOx limit through the use of Boiler Op recommended control settings and without NOx burners. Importantly, any software like Boiler Op cannot be used alone. Its application must be in concert with human intelligence to ensure unit safety, reliability and accurate data collection.« less

P and W propulsion systems studies results/status

NASA Technical Reports Server (NTRS)

Smith, Martin G., Jr.; Champagne, George A.

1992-01-01

The topics covered include the following: Pratt and Whitney (P&W) propulsion systems studies - NASA funded efforts to date; P&W engine concepts; P&W combustor focus - rich burn quick quench (RBQQ) concept; mixer ejector nozzle concept - large flow entrainment reduces jet noise; technology impact on NO(x) emissions - mature RBQQ combustor reduces NO(x) up to 85 percent; technology impact on sideline noise characteristics of Mach 2.4 turbine bypass engines (TBE's) - 600 lb/sec airflow size; technology impact on takeoff gross weight (TOGW) - provides up to 12 percent TOGW reduction; HSCT quiet engine concepts; TBE inlet valve/ejector nozzle concept schematic; mixed flow turbofan study; and exhaust nozzle conceptual design.

Reduction of aircraft gas turbine engine pollutant emissions

NASA Technical Reports Server (NTRS)

Diehl, L. A.

1978-01-01

To accomplish simultaneous reduction of unburned hydrocarbons, carbon monoxide, and oxides of nitrogen, required major modifications to the combustor. The modification most commonly used was a staged combustion technique. While these designs are more complicated than production combustors, no insurmountable operational difficulties were encountered in either high pressure rig or engine tests which could not be resolved with additional normal development. The emission reduction results indicate that reductions in unburned hydrocarbons were sufficient to satisfy both near and far-termed EPA requirements. Although substantial reductions were observed, the success in achieving the CO and NOx standards was mixed and depended heavily on the engine/engine cycle on which it was employed. Technology for near term CO reduction was satisfactory or marginally satisfactory. Considerable doubt exists if this technology will satisfy all far-term requirements.

Status of NASA aircraft engine emission reduction and upper atmosphere measurement programs

NASA Technical Reports Server (NTRS)

Rudey, R. A.; Lezberg, E. A.

1976-01-01

Advanced emission reduction techniques for five existing aircraft gas turbine engines are evaluated. Progress made toward meeting the 1979 EPA standards in rig tests of combustors for the five engines is reported. Results of fundamental combustion studies suggest the possibility of a new generation of jet engine combustor technology that would reduce oxides-of-nitrogen (NOx) emissions far below levels currently demonstrated in the engine-related programs. The Global Air Sampling Program (GAS) is now in full operation and is providing data on constituent measurements of ozone and other minor upper-atmosphere species related to aircraft emissions.

System and method for diagnosing EGR performance using NOx sensor

DOEpatents

Mazur, Christopher John

2003-12-23

A method and system for diagnosing a condition of an EGR valve used in an engine system. The EGR valve controls the portion exhaust gases produced by such engine system and fed back to an intake of such engine system. The engine system includes a NOx sensor for measuring NOx in such exhaust. The method includes: determining a time rate of change in NOx measured by the NOx sensor; comparing the determined time rate of change in the measured NOx with a predetermined expected time rate of change in measured NOx; and determining the condition of the EGR valve as a function of such comparison. The method also includes: determining from NOx measured by the NOx sensor and engine operating conditions indications of instances when samples of such measured NOx are greater than an expected maximum NOx level for such engine condition and less than an expected minimum NOx level for such engine condition; and determining the condition of the EGR valve as a function of a statistical analysis of such indications. The method includes determining whether the NOx sensor is faulty and wherein the EGR condition determining includes determining whether the NOx sensor is faulty.

Method and apparatus to selectively reduce NO.sub.x in an exhaust gas feedstream

DOEpatents

Schmieg, Steven J [Troy, MI; Blint, Richard J [Shelby Township, MI; Den, Ling [Sterling Heights, MI; Viola, Michael B [Macomb Township, MI; Lee, Jong-Hwan [Rochester Hills, MI

2011-08-30

A method and apparatus are described to selectively reduce NO.sub.x emissions of an internal combustion engine. An exhaust aftertreatment system includes an injection device operative to dispense a hydrocarbon reductant upstream of a silver-alumina catalytic reactor device. A control system determines a NO.sub.x concentration and hydrocarbon/NOx ratio based upon selected parameters of the exhaust gas feedstream and dispenses hydrocarbon reductant during lean engine operation. Included is a method to control elements of the feedstream during lean operation. The hydrocarbon reductant may include engine fuel.

Water Injection Feasibility for Boeing 747 Aircraft

NASA Technical Reports Server (NTRS)

Daggett, David L.

2005-01-01

Can water injection be offered at a reasonable cost to large airplane operators to reduce takeoff NO( sub x) emissions? This study suggests it may be possible. This report is a contract deliverable to NASA Glenn Research Center from the prime contractor, The Boeing Commercial Airplane Company of Seattle, WA. This study was supported by a separate contract to the Pratt & Whitney Engine Company of Hartford, CT (contract number NNC04QB58P). Aviation continues to grow and with it, environmental pressures are increasing for airports that service commercial airplanes. The feasibility and performance of an emissions-reducing technology, water injection, was studied for a large commercial airplane (e.g., Boeing 747 with PW4062 engine). The primary use of the water-injection system would be to lower NOx emissions while an important secondary benefit might be to improve engine turbine life. A tradeoff exists between engine fuel efficiency and NOx emissions. As engines improve fuel efficiency, by increasing the overall pressure ratio of the engine s compressor, the resulting increased gas temperature usually results in higher NOx emissions. Low-NO(sub x) combustors have been developed for new airplanes to control the increases in NO(sub x) emissions associated with higher efficiency, higher pressure ratio engines. However, achieving a significant reduction of NO(sub x) emissions at airports has been challenging. Using water injection during takeoff has the potential to cut engine NO(sub x) emissions some 80 percent. This may eliminate operating limitations for airplanes flying into airports with emission constraints. This study suggests an important finding of being able to offer large commercial airplane owners an emission-reduction technology that may also save on operating costs.

Nitrogen stable isotope composition (δ15N) of vehicle-emitted NOx.

PubMed

Walters, Wendell W; Goodwin, Stanford R; Michalski, Greg

2015-02-17

The nitrogen stable isotope ratio of NOx (δ(15)N-NOx) has been proposed as a regional indicator for NOx source partitioning; however, knowledge of δ(15)N values from various NOx emission sources is limited. This study presents a detailed analysis of δ(15)N-NOx emitted from vehicle exhaust, the largest source of anthropogenic NOx. To accomplish this, NOx was collected from 26 different vehicles, including gasoline and diesel-powered engines, using a modification of a NOx collection method used by the United States Environmental Protection Agency, and δ(15)N-NOx was analyzed. The vehicles sampled in this study emitted δ(15)N-NOx values ranging from -19.1 to 9.8‰ that negatively correlated with the emitted NOx concentrations (8.5 to 286 ppm) and vehicle run time because of kinetic isotope fractionation effects associated with the catalytic reduction of NOx. A model for determining the mass-weighted δ(15)N-NOx from vehicle exhaust was constructed on the basis of average commute times, and the model estimates an average value of -2.5 ± 1.5‰, with slight regional variations. As technology improvements in catalytic converters reduce cold-start emissions in the future, it is likely to increase current δ(15)N-NOx values emitted from vehicles.

40 CFR 1042.110 - Recording reductant use and other diagnostic functions.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) The onboard computer log must record in nonvolatile computer memory all incidents of engine operation... such operation in nonvolatile computer memory. You are not required to monitor NOX concentrations...

Investigation of Mixed Oxide Catalysts for NO Oxidation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Szanyi, Janos; Karim, Ayman M.; Pederson, Larry R.

2014-12-09

The oxidation of engine-generated NO to NO2 is an important step in the reduction of NOx in lean engine exhaust because NO2 is required for the performance of the LNT technology [2], and it enhances the activities of ammonia selective catalytic reduction (SCR) catalysts [1]. In particular, for SCR catalysts an NO:NO2 ratio of 1:1 is most effective for NOx reduction, whereas for LNT catalysts, NO must be oxidized to NO2 before adsorption on the storage components. However, NO2 typically constitutes less than 10% of NOx in lean exhaust, so catalytic oxidation of NO is essential. Platinum has been foundmore » to be especially active for NO oxidation, and is widely used in DOC and LNT catalysts. However, because of the high cost and poor thermal durability of Pt-based catalysts, there is substantial interest in the development of alternatives. The objective of this project, in collaboration with partner General Motors, is to develop mixed metal oxide catalysts for NO oxidation, enabling lower precious metal usage in emission control systems. [1] M. Koebel, G. Madia, and M. Elsener, Catalysis Today 73, 239 (2002). [2] C. H. Kim, G. S. Qi, K. Dahlberg, and W. Li, Science 327, 1624 (2010).« less

40 CFR 1042.110 - Recording reductant use and other diagnostic functions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... all the information broadcast by an engine's onboard computers and electronic control units. (d) For Category 3 engines equipped with on-off NOX controls (as allowed by § 1042.115(g)), you must also equip... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION...

40 CFR 1042.110 - Recording reductant use and other diagnostic functions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... all the information broadcast by an engine's onboard computers and electronic control units. (d) For Category 3 engines equipped with on-off NOX controls (as allowed by § 1042.115(g)), you must also equip... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION...

40 CFR 1042.110 - Recording reductant use and other diagnostic functions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... all the information broadcast by an engine's onboard computers and electronic control units. (d) For Category 3 engines equipped with on-off NOX controls (as allowed by § 1042.115(g)), you must also equip... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION...

40 CFR 1042.110 - Recording reductant use and other diagnostic functions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... all the information broadcast by an engine's onboard computers and electronic control units. (d) For Category 3 engines equipped with on-off NOX controls (as allowed by § 1042.115(g)), you must also equip... (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION...

Uniformity index measurement technology using thermocouples to improve performance in urea-selective catalytic reduction systems

NASA Astrophysics Data System (ADS)

Park, Sangki; Oh, Jungmo

2018-05-01

The current commonly used nitrogen oxides (NOx) emission reduction techniques employ hydrocarbons (HCs), urea solutions, and exhaust gas emissions as the reductants. Two of the primary denitrification NOx (DeNOx) catalyst systems are the HC-lean NOx trap (HC-LNT) catalyst and urea-selective catalytic reduction (urea-SCR) catalyst. The secondary injection method depends on the type of injector, injection pressure, atomization, and spraying technique. In addition, the catalyst reaction efficiency is directly affected by the distribution of injectors; hence, the uniformity index (UI) of the reductant is very important and is the basis for system optimization. The UI of the reductant is an indicator of the NOx conversion efficiency (NCE), and good UI values can reduce the need for a catalyst. Therefore, improving the UI can reduce the cost of producing a catalytic converter, which are expensive due to the high prices of the precious metals contained therein. Accordingly, measurement of the UI is an important process in the development of catalytic systems. Two of the commonly used methods for measuring the reductant UI are (i) measuring the exhaust emissions at many points located upstream/downstream of the catalytic converter and (ii) acquisition of a reductant distribution image on a section of the exhaust pipe upstream of the catalytic converter. The purpose of this study is to develop a system and measurement algorithms to measure the exothermic response distribution in the exhaust gas as the reductant passes through the catalytic converter of the SCR catalyst system using a set of thermocouples downstream of the SCR catalyst. The system is used to measure the reductant UI, which is applied in real-time to the actual SCR system, and the results are compared for various types of mixtures for various engine operating conditions and mixer types in terms of NCE.

An Assessment of NASA Aeropropulsion Technologies: A System Study

NASA Technical Reports Server (NTRS)

Tong, Michael T.; Jones, Scott M.; Haller, William J.

2007-01-01

Aviation industry s robust growth rate has given rise to growing concerns about the contribution that aviation emissions will make to local air quality and global climate change. Over the last several years, NASA has been engaged in the development of aeropropulsion technologies with specific objectives to reduce aircraft emissions. A system analysis was performed to evaluate the potential impact of these propulsion technologies on aircraft CO2 (directly proportional to fuel burn) and NOx reductions. A large subsonic aircraft, with two 396-kN thrust (85,000-pound) engines was chosen for the study. Performance benefit estimates are presented for each technology, with a summary of potential emissions reduction possible from the development of these technologies. The results show that NASA s aeropropulsion technologies have the potential to significantly reduce the CO2 and NO(x) emissions. The results are used to support informed decision-making on the development of aeropropulsion technology portfolio for CO2 and NO(x) reductions.

Usability of food industry waste oils as fuel for diesel engines.

PubMed

Winfried, Russ; Roland, Meyer-Pittroff; Alexander, Dobiasch; Jürgen, Lachenmaier-Kölch

2008-02-01

Two cogeneration units were each fitted with a prechamber (IDI) diesel engine in order to test the feasibility of using waste oils from the food industry as a fuel source, and additionally to test emissions generated by the combustion of these fuels. Esterified waste oils and animal fats as well as mustard oil were tested and compared to the more or less "common" fuels: diesel, rapeseed oil and rapeseed methyl ester. The results show that, in principle, each of these fuels is suitable for use in a prechamber diesel engine. Engine performance can be maintained at a constant level. Without catalytic conversion, the nitrogen oxides emissions were comparable. A significant reduction in NO(x) was achieved through the injection of urea. Combining a urea injection with the SCR catalytic converter reduced NO(x) emissions between 53% and 67%. The carbon monoxide emissions from waste oils are not significantly different from those of "common" fuels and can be reduced the same way as of hydrocarbon emissions, through utilization of a catalytic converter. The rate of carbon monoxide reduction by catalytic conversion was 84-86%. A lower hydrocarbon concentration was associated with fuels of agricultural origin. With the catalytic converter a reduction of 29-42% achieved. Each prechamber diesel engine exhibited its own characteristic exhaust, which was independent of fuel type. The selective catalytic reduction of the exhaust emissions can be realized without restriction using fuels of agricultural origin.

Emission reduction from diesel engine using fumigation methanol and diesel oxidation catalyst.

PubMed

Zhang, Z H; Cheung, C S; Chan, T L; Yao, C D

2009-07-15

This study is aimed to investigate the combined application of fumigation methanol and a diesel oxidation catalyst for reducing emissions of an in-use diesel engine. Experiments were performed on a 4-cylinder naturally-aspirated direct-injection diesel engine operating at a constant speed of 1800 rev/min for five engine loads. The experimental results show that at low engine loads, the brake thermal efficiency decreases with increase in fumigation methanol; but at high loads, it slightly increases with increase in fumigation methanol. The fumigation method results in a significant increase in hydrocarbon (HC), carbon monoxide (CO), and nitrogen dioxide (NO(2)) emissions, but decrease in nitrogen oxides (NO(x)), smoke opacity and the particulate mass concentration. For the submicron particles, the total number of particles decreases. In all cases, there is little change in geometrical mean diameter of the particles. After catalytic conversion, the HC, CO, NO(2), particulate mass and particulate number concentrations were significantly reduced at medium to high engine loads; while the geometrical mean diameter of the particles becomes larger. Thus, the combined use of fumigation methanol and diesel oxidation catalyst leads to a reduction of HC, CO, NO(x), particulate mass and particulate number concentrations at medium to high engine loads.

Locomotive Emission and Engine Idle Reduction Technology Demonstration Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

John R. Archer

2005-03-14

In response to a United States Department of Energy (DOE) solicitation, the Maryland Energy Administration (MEA), in partnership with CSX Transportation, Inc. (CSXT), submitted a proposal to DOE to support the demonstration of Auxiliary Power Unit (APU) technology on fifty-six CSXT locomotives. The project purpose was to demonstrate the idle fuel savings, the Nitrous Oxide (NOX) emissions reduction and the noise reduction capabilities of the APU. Fifty-six CSXT Baltimore Division locomotives were equipped with APUs, Engine Run Managers (ERM) and communications equipment to permit GPS tracking and data collection from the locomotives. Throughout the report there is mention of themore » percent time spent in the State of Maryland. The fifty-six locomotives spent most of their time inside the borders of Maryland and some spent all their time inside the state borders. Usually when a locomotive traveled beyond the Maryland State border it was into an adjoining state. They were divided into four groups according to assignment: (1) Power Unit/Switcher Mate units, (2) Remote Control units, (3) SD50 Pusher units and (4) Other units. The primary data of interest were idle data plus the status of the locomotive--stationary or moving. Also collected were main engine off, idling or working. Idle data were collected by county location, by locomotive status (stationary or moving) and type of idle (Idle 1, main engine idling, APU off; Idle 2, main engine off, APU on; Idle 3, main engine off, APU off; Idle 4, main engine idle, APU on). Desirable main engine idle states are main engine off and APU off or main engine off and APU on. Measuring the time the main engine spends in these desirable states versus the total time it could spend in an engine idling state allows the calculation of Percent Idle Management Effectiveness (%IME). IME is the result of the operation of the APU plus the implementation of CSXT's Warm Weather Shutdown Policy. It is difficult to separate the two. The units demonstrated an IME of 64% at stationary idle for the test period. The data collected during calendar year 2004 demonstrated that 707,600 gallons of fuel were saved and 285 tons of NOX were not emitted as a result of idle management in stationary idle, which translates to 12,636 gallons and 5.1 tons of NOx per unit respectively. The noise reduction capabilities of the APU demonstrated that at 150 feet from the locomotive the loaded APU with the main engine shut down generated noise that was only marginally above ambient noise level.« less

Pollution technology program, can-annular combustor engines

NASA Technical Reports Server (NTRS)

Roberts, R.; Fiorentino, A. J.; Greene, W.

1976-01-01

A Pollution Reduction Technology Program to develop and demonstrate the combustor technology necessary to reduce exhaust emissions for aircraft engines using can-annular combustors is described. The program consisted of design, fabrication, experimental rig testing and assessment of results and was conducted in three program elements. The combustor configurations of each program element represented increasing potential for meeting the 1979 Environmental Protection Agency (EPA) emission standards, while also representing increasing complexity and difficulty of development and adaptation to an operational engine. Experimental test rig results indicate that significant reductions were made to the emission levels of the baseline JT8D-17 combustor by concepts in all three program elements. One of the Element I single-stage combustors reduced carbon monoxide to a level near, and total unburned hydrocarbons (THC) and smoke to levels below the 1979 EPA standards with little or no improvement in oxides of nitrogen. The Element II two-stage advanced Vorbix (vortex burning and mixing) concept met the standard for THC and achieved significant reductions in CO and NOx relative to the baseline. Although the Element III prevaporized-premixed concept reduced high power NOx below the Element II results, there was no improvement to the integrated EPA parameter relative to the Vorbix combustor.

Avco Lycoming/NASA contract status. [on reduction of emissions from aircraft piston engines

NASA Technical Reports Server (NTRS)

Duke, L. C.

1976-01-01

The standards promulgated by the Environmental Protection Agency (EPA) for carbon monoxide (CO), unburned hydrocarbon (HC), and oxides-of-nitrogen (NOx) emissions were the basis in a study of ways to reduce emissions from aircraft piston engines. A variable valve timing system, ultrasonic fuel atomization, and ignition system changes were postulated.

Experimental clean combustor program, phase 1

NASA Technical Reports Server (NTRS)

Bahr, D. W.; Gleason, C. C.

1975-01-01

Full annular versions of advanced combustor designs, sized to fit within the CF6-50 engine, were defined, manufactured, and tested at high pressure conditions. Configurations were screened, and significant reductions in CO, HC, and NOx emissions levels were achieved with two of these advanced combustor design concepts. Emissions and performance data at a typical AST cruise condition were also obtained along with combustor noise data as a part of an addendum to the basic program. The two promising combustor design approaches evolved in these efforts were the Double Annular Combustor and the Radial/Axial Combustor. With versions of these two basic combustor designs, CO and HC emissions levels at or near the target levels were obtained. Although the low target NOx emissions level was not obtained with these two advanced combustor designs, significant reductions were relative to the NOx levels of current technology combustors. Smoke emission levels below the target value were obtained.

NASA Project Develops Next-Generation Low-Emissions Combustor Technologies

NASA Technical Reports Server (NTRS)

Lee, Chi-Ming; Chang, Clarence T.; Herbon, John T.; Kramer, Stephen K.

2013-01-01

NASA's Environmentally Responsible Aviation (ERA) Project is working with industry to develop the fuel flexible combustor technologies for a new generation of low-emissions engine targeted for the 2020 timeframe. These new combustors will reduce nitrogen oxide (NOx) emissions to half of current state-of-the-art (SOA) combustors, while simultaneously reducing noise and fuel burn. The purpose of the low NOx fuel-flexible combustor research is to advance the Technology Readiness Level (TRL) and Integration Readiness Level (IRL) of a low NOx, fuel flexible combustor to the point where it can be integrated in the next generation of aircraft. To reduce project risk and optimize research benefit NASA chose to found two Phase 1 contracts. The first Phase 1 contracts went to engine manufactures and were awarded to: General Electric Company, and Pratt & Whitney Company. The second Phase 1 contracts went to fuel injector manufactures Goodrich Corporation, Parker Hannifin Corporation, and Woodward Fuel System Technology. In 2012, two sector combustors were tested at NASA's ASCR. The results indicated 75% NOx emission reduction below the 2004 CAEP/6 regulation level.

Enhanced xylose fermentation by engineered yeast expressing NADH oxidase through high cell density inoculums.

PubMed

Zhang, Guo-Chang; Turner, Timothy L; Jin, Yong-Su

2017-03-01

Accumulation of reduced byproducts such as glycerol and xylitol during xylose fermentation by engineered Saccharomyces cerevisiae hampers the economic production of biofuels and chemicals from cellulosic hydrolysates. In particular, engineered S. cerevisiae expressing NADPH-linked xylose reductase (XR) and NAD + -linked xylitol dehydrogenase (XDH) produces substantial amounts of the reduced byproducts under anaerobic conditions due to the cofactor difference of XR and XDH. While the additional expression of a water-forming NADH oxidase (NoxE) from Lactococcus lactis in engineered S. cerevisiae with the XR/XDH pathway led to reduced glycerol and xylitol production and increased ethanol yields from xylose, volumetric ethanol productivities by the engineered yeast decreased because of growth defects from the overexpression of noxE. In this study, we introduced noxE into an engineered yeast strain (SR8) exhibiting near-optimal xylose fermentation capacity. To overcome the growth defect caused by the overexpression of noxE, we used a high cell density inoculum for xylose fermentation by the SR8 expressing noxE. The resulting strain, SR8N, not only showed a higher ethanol yield and lower byproduct yields, but also exhibited a high ethanol productivity during xylose fermentation. As noxE overexpression elicits a negligible growth defect on glucose conditions, the beneficial effects of noxE overexpression were substantial when a mixture of glucose and xylose was used. Consumption of glucose led to rapid cell growth and therefore enhanced the subsequent xylose fermentation. As a result, the SR8N strain produced more ethanol and fewer byproducts from a mixture of glucose and xylose than the parental SR8 strain without noxE overexpression. Our results suggest that the growth defects from noxE overexpression can be overcome in the case of fermenting lignocellulose-derived sugars such as glucose and xylose.

The effect of fuel processes on heavy duty automotive diesel engine emissions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reynolds, E.G.

1995-12-31

The effect of fuel quality on exhaust emissions from 2 heavy duty diesel engines has been measured over the ECE R49 test cycle. The engines were selected to represent technologies used to meet Euro 1 and 2 emission standards (1992/93 and 1995/96); engines 1 and 2 respectively. The test fuels were prepared by a combination of processing, blending and additive treatment. When comparing the emissions from engines 1 and 2, using base line data generated on the CEC reference fuel RF73-T-90, engine technology had the major effect on emission levels. Engine 2 reduced both particulate matter (PM) and carbon monoxidemore » levels by approximately 50%, with total hydrocarbon (THC) being approximately 75% lower. Oxides of nitrogen levels were similar for both engines. The variations in test fuel quality had marginal effects on emissions, with the two engines giving directionally opposite responses in some cases. For instance, there was an effect on CO and NOx but where one engine showed a reduction the other gave an increase. There were no significant changes in THC emissions from either engine when operating on any of the test fuels. When the reference fuel was hydrotreated, engine 1 showed a trend towards reduced particulate and NOx but with CO increasing. Engine 2 also showed a trend for reduced particulate levels, with an increase in NOx and no change in CO. Processing to reduce the final boiling point of the reference fuel showed a trend towards reduced particulate emissions with CO increasing on engine 1 but decreasing on engine 2.« less

I.C. Engine emission reduction by copper oxide catalytic converter

NASA Astrophysics Data System (ADS)

Venkatesan, S. P.; Shubham Uday, Desai; Karan Hemant, Borana; Rajarshi Kushwanth Goud, Kagita; Lakshmana Kumar, G.; Pavan Kumar, K.

2017-05-01

The toxic gases emitted from diesel engines are more than petrol engines. Predicting the use of diesel engines, even more in future, this system is developed and can be used to minimize the harmful gases. Toxic gases include NOX, CO, HC and Smoke which are harmful to the atmosphere as well as to the human beings. The main aim of this work is to fabricate system, where the level of intensity of toxic gases is controlled through chemical reaction to more agreeable level. This system acts itself as an exhaust system; hence there is no needs to fit separate the silencer. The whole assembly is fitted in the exhaust pipe from engine. In this work, catalytic converter with copper oxide as a catalyst, by replacing noble catalysts such as platinum, palladium and rhodium is fabricated and fitted in the engine exhaust. With and without catalytic converter, the experimentations are carried out at different loads such as 0%, 25%, 50%, 75%, and 100% of maximum rated load. From the experimental results it is found that the maximum reduction is 32%, 61% and 21% for HC, NOx and CO respectively at 100% of maximum rated load when compared to that of without catalytic converter. This catalytic converter system is cash effective and more economical than the existing catalytic converter.

Emission Studies in CI Engine using LPG and Palm Kernel Methyl Ester as Fuels and Di-ethyl Ether as an Additive

NASA Astrophysics Data System (ADS)

Dora, Nagaraju; Jothi, T. J. Sarvoththama

2018-05-01

The present study investigates the effectiveness of using di-ethyl ether (DEE) as the fuel additive in engine performance and emissions. Experiments are carried out in a single cylinder four stroke diesel engine at constant speed. Two different fuels namely liquefied petroleum gas (LPG) and palm kernel methyl ester (PKME) are used as primary fuels with DEE as the fuel additive. LPG flow rates of 0.6 and 0.8 kg/h are considered, and flow rate of DEE is varied to maintain the constant engine speed. In case of PKME fuel, it is blended with diesel in the latter to the former ratio of 80:20, and DEE is varied in the volumetric proportion of 1 and 2%. Results indicate that for the engine operating in LPG-DEE mode at 0.6 kg/h of LPG, the brake thermal efficiency is lowered by 26%; however, NOx is subsequently reduced by around 30% compared to the engine running with only diesel fuel at 70% load. Similarly, results of PKME blended fuel showed a drastic reduction in the NOx and CO emissions. In these two modes of operation, DEE is observed to be significant fuel additive regarding emissions reduction.

Investigation of the spray characteristics for a secondary fuel injection nozzle using a digital image processing method

NASA Astrophysics Data System (ADS)

Jeong, Haeyoung; Lee, Kihyung; Ikeda, Yuji

2007-05-01

There are many ways to reduce diesel engine exhaust emissions. However, NOx emission is difficult to reduce because the hydrocarbon (HC) concentration in a diesel engine is not sufficient for NOx conversion. Therefore, in order to create stoichiometric conditions in the De-NOx catalyst, a secondary injection system is designed to inject liquid HC into the exhaust pipe. The atomization and distribution characteristics of the HC injected from a secondary injector are key technologies to obtain a high NOx conversion because inhomogeneous droplets of injected HC cause not only high fuel consumption but also deterioration of NOx emission. This paper describes the spray characteristics of a secondary injector including the spray angle, penetration length and breakup behaviour of the spray to optimize the reduction rate of the NOx catalyst. In this study, various optical diagnostics were applied to investigate these spray characteristics, the atomization mechanism and spray developing process. The visualization and image processing method for the spray pulsation were developed by high speed photography. The influence of the fuel supply pressure on the spray behaviour and a more detailed spray developing process have been analysed experimentally using image processing. Finally, the experimental results were used to correlate the spray structure to the injection system performance and to provide a design guide for a secondary injector nozzle.

System Study: Technology Assessment and Prioritizing Update

NASA Technical Reports Server (NTRS)

2008-01-01

For the Intelligent Engine System (Propulsion 21) study, each technology was evaluated to determine the impact to fuel burn, acoustics, and NOx emissions. The optimum combination of technologies and their overall benefits to the system were also evaluated, resulting in noise improvement potential of 1.89 EPNdB cumulative margin,-1.34 percent fuel burn, and 50 percent NOx reduction from the 2015 UEET-QAT baseline. All the technology evaluations, except T18-20D, were based on newengines, where the engine was resized to obtain the maximum system benefit while maintaining the same cycle parameters as the 2015 UEET-QAT baseline. The impact of turbine clearance control on deteriorated engines, T18-20D, was also evaluated. Recommendations for future system study work include, but were not limited to, validation of a university-developed engine deterioration model and customer value analysis as figures of merit beside fuel burn, emissions, and acoustics.

Experimental study on the particulate matter and nitrogenous compounds from diesel engine retrofitted with DOC+CDPF+SCR

NASA Astrophysics Data System (ADS)

Zhang, Yunhua; Lou, Diming; Tan, Piqiang; Hu, Zhiyuan

2018-03-01

The increasingly stringent emission regulations will mandate the retrofit of after-treatment devices for in-use diesel vehicles, in order to reduce their substantial particulate matter and nitrogen oxides (NOX) emissions. In this paper, a combination of DOC (diesel oxidation catalyst), CDPF (catalytic diesel particulate filter) and SCR (selective catalytic reduction) retrofit for a heavy-duty diesel engine was employed to perform experiment on the engine test bench to evaluate the effects on the particulate matter emissions including particle number (PN), particle mass (PM), particle size distributions and nitrogenous compounds emissions including NOX, nitrogen dioxide (NO2)/NOX, nitrous oxide (N2O) and ammonia (NH3) slip. In addition, the urea injection was also of our concern. The results showed that the DOC+CDPF+SCR retrofit almost had no adverse effect on the engine power and fuel consumption. Under the test loads, the upstream DOC and CDPF reduced the PN and PM by an average of 91.6% and 90.9%, respectively. While the downstream SCR brought about an average decrease of 85% NOX. Both PM and NOX emission factors based on this retrofit were lower than China-Ⅳ limits (ESC), and even lower than China-Ⅴ limits (ESC) at medium and high loads. The DOC and CDPF changed the particle size distributions, leading to the increase in the proportion of accumulation mode particles and the decrease in the percentage of nuclear mode particles. This indicates that the effect of DOC and CDPF on nuclear mode particles was better than that of accumulation mode ones. The upstream DOC could increase the NO2/NOX ratio to 40%, higher NO2/NOX ratio improved the efficiency of CDPF and SCR. Besides, the N2O emission increased by an average of 2.58 times after the retrofit and NH3 slip occurred with the average of 26.7 ppm. The rate of urea injection was roughly equal to 8% of the fuel consumption rate. The DOC+CDPF+SCR retrofit was proved a feasible and effective measurement in terms of reducing particulate emissions and NOX simultaneously for in-use engine. However, it also resulted in higher N2O emission, NH3 slip as well as urea injecting strategy problem which should be of further concern.

Progress in catalytic ignition fabrication and modeling : fabrication part 1.

DOT National Transportation Integrated Search

2012-06-01

Previous engine testing with Catalytic Plasma Torch (CPT) technology at the University of Idaho has shown promising results in : the reduction of NOx and CO emissions. Because this technology is not yet well characterized, past research has indicated...

Low NO/x/ heavy fuel combustor program

NASA Technical Reports Server (NTRS)

Lister, E.; Niedzwiecki, R. W.; Nichols, L.

1980-01-01

The paper deals with the 'Low NO/x/ Heavy Fuel Combustor Program'. Main program objectives are to generate and demonstrate the technology required to develop durable gas turbine combustors for utility and industrial applications, which are capable of sustained, environmentally acceptable operation with minimally processed petroleum residual fuels. The program will focus on 'dry' reductions of oxides of nitrogen (NO/x/), improved combustor durability and satisfactory combustion of minimally processed petroleum residual fuels. Other technology advancements sought include: fuel flexibility for operation with petroleum distillates, blends of petroleum distillates and residual fuels, and synfuels (fuel oils derived from coal or shale); acceptable exhaust emissions of carbon monoxide, unburned hydrocarbons, sulfur oxides and smoke; and retrofit capability to existing engines.

A Fuel-Based Assessment of On-Road and Off-Road Mobile Source Emission Trends

NASA Astrophysics Data System (ADS)

Dallmann, T. R.; Harley, R. A.

2009-12-01

Mobile sources contribute significantly to emissions of nitrogen oxides (NOx) and fine particulate matter (PM2.5) in the United States. These emissions lead to a variety of environmental concerns including adverse human health effects and climate change. In the electric power sector, sulfur dioxide (SO2) and NOx emissions from power plants are measured directly using continuous emission monitoring systems. In contrast for mobile sources, statistical models are used to estimate average emissions from a very large and diverse population of engines. Despite much effort aimed at improving them, mobile source emission inventories continue to have large associated uncertainties. Alternate methods are needed to help evaluate estimates of mobile source emissions and quantify and reduce the associated uncertainties. In this study, a fuel-based approach is used to estimate emissions from mobile sources, including on-road and off-road gasoline and diesel engines. In this approach, engine activity is measured by fuel consumed (in contrast EPA mobile source emission models are based on vehicle km of travel and total amount of engine work output for on-road and off-road engines, respectively). Fuel consumption is defined in this study based on highway fuel tax reports for on-road engines, and from surveys of fuel wholesalers who sell tax-exempt diesel fuel for use in various off-road sectors such as agriculture, construction, and mining. Over the decade-long time period (1996-2006) that is the focus of the present study, national sales of taxable gasoline and diesel fuel intended for on-road use increased by 15 and 43%, respectively. Diesel fuel use by off-road equipment increased by about 20% over the same time period. Growth in fuel consumption offset some of the reductions in pollutant emission factors that occurred during this period. This study relies on in-use measurements of mobile source emission factors, for example from roadside and tunnel studies, remote sensing, and plume capture experiments. Extensive in-use emissions data are available for NOx, especially for on-road engines. Measurements of exhaust PM2.5 emission factors are sparse in comparison. For NOx, there have been dramatic (factor of 2) decreases in emission factors for on-road gasoline engines between 1996 and 2006, due to use of improved catalytic converters on most engines. In contrast, diesel NOx emission factors decreased more gradually over the same time period. Exhaust PM2.5 emission factors appear to have decreased for most engine categories, but emission uncertainties are large for this pollutant. Pollutant emissions were estimated by combining fuel sales with emission factors expressed per unit of fuel burned. Diesel engines are the dominant mobile source of both NOx and PM2.5; the diesel contribution to NOx has increased over time as gasoline engine emissions have declined. Comparing fuel-based emission estimates with EPA’s national emission inventory led to the following conclusions: (1) total emissions of both NOx and PM2.5 estimated by two different methods were similar, (2) the distribution of source contributions to these totals differ significantly, with higher relative contributions coming from on-road diesel engines in this study compared to EPA.

A hybrid plasma-chemical system for high-NOx flue gas treatment

NASA Astrophysics Data System (ADS)

Chmielewski, Andrzej G.; Zwolińska, Ewa; Licki, Janusz; Sun, Yongxia; Zimek, Zbigniew; Bułka, Sylwester

2018-03-01

The reduction of high concentrations of NOx and SO2 from simulated flue gas has been studied. Our aim was to optimise energy consumption for NOx and SO2 removal from off-gases from a diesel generator using heavy fuel oil. A hybrid process: electron beam (EB) plasma and wet scrubber has been applied. A much higher efficiency of NOx and SO2 removal was achieved in comparison to dry, ammonia free, electron beam flue gas treatment (EBFGT). A recorded removal from a concentration of 1500 ppm NOx reached 49% at a low dose of 6.5 kGy, while only 2% NOx was removed at the same dose if EB only was applied. For SO2, removal efficiency at a dose of 6.5 kGy increased from 15% (EB only) to 84% when sea water was used as a wet scrubber agent for 700 ppm SO2. The results of this study indicate that EB combined with wet scrubber is a very promising technology to be applied for removal of high concentrations of NOx and SO2 emitted from diesel engines operated e.g. on cargo ships, which are the main sources of SO2 and NOx pollution along their navigation routes.

Regulated and unregulated emissions from modern 2010 emissions-compliant heavy-duty on-highway diesel engines

PubMed Central

Khalek, Imad A.; Blanks, Matthew G.; Merritt, Patrick M.; Zielinska, Barbara

2015-01-01

The U.S. Environmental Protection Agency (EPA) established strict regulations for highway diesel engine exhaust emissions of particulate matter (PM) and nitrogen oxides (NOx) to aid in meeting the National Ambient Air Quality Standards. The emission standards were phased in with stringent standards for 2007 model year (MY) heavy-duty engines (HDEs), and even more stringent NOX standards for 2010 and later model years. The Health Effects Institute, in cooperation with the Coordinating Research Council, funded by government and the private sector, designed and conducted a research program, the Advanced Collaborative Emission Study (ACES), with multiple objectives, including detailed characterization of the emissions from both 2007- and 2010-compliant engines. The results from emission testing of 2007-compliant engines have already been reported in a previous publication. This paper reports the emissions testing results for three heavy-duty 2010-compliant engines intended for on-highway use. These engines were equipped with an exhaust diesel oxidation catalyst (DOC), high-efficiency catalyzed diesel particle filter (DPF), urea-based selective catalytic reduction catalyst (SCR), and ammonia slip catalyst (AMOX), and were fueled with ultra-low-sulfur diesel fuel (~6.5 ppm sulfur). Average regulated and unregulated emissions of more than 780 chemical species were characterized in engine exhaust under transient engine operation using the Federal Test Procedure cycle and a 16-hr duty cycle representing a wide dynamic range of real-world engine operation. The 2010 engines’ regulated emissions of PM, NOX, nonmethane hydrocarbons, and carbon monoxide were all well below the EPA 2010 emission standards. Moreover, the unregulated emissions of polycyclic aromatic hydrocarbons (PAHs), nitroPAHs, hopanes and steranes, alcohols and organic acids, alkanes, carbonyls, dioxins and furans, inorganic ions, metals and elements, elemental carbon, and particle number were substantially (90 to >99%) lower than pre-2007-technology engine emissions, and also substantially (46 to >99%) lower than the 2007-technology engine emissions characterized in the previous study. Implications: Heavy-duty on-highway diesel engines equipped with DOC/DPF/SCR/AMOX and fueled with ultra-low-sulfur diesel fuel produced lower emissions than the stringent 2010 emission standards established by the U.S. Environmental Protection Agency. They also resulted in significant reductions in a wide range of unregulated toxic emission compounds relative to older technology engines. The increased use of newer technology (2010+) diesel engines in the on-highway sector and the adaptation of such technology by other sectors such as nonroad, displacing older, higher emissions engines, will have a positive impact on ambient levels of PM, NOx, and volatile organic compounds, in addition to many other toxic compounds. PMID:26037832

NOx emissions from Euro IV busses with SCR systems associated with urban, suburban and freeway driving patterns.

PubMed

Fu, Mingliang; Ge, Yunshan; Wang, Xin; Tan, Jianwei; Yu, Linxiao; Liang, Bin

2013-05-01

NOx and particulate matter (PM) emissions from heavy-duty diesel vehicles (HDVs) have become the most important sources of pollutants affecting urban air quality in China. In recent years, a series of emission control strategies and diesel engine polices have been introduced that require advanced emission control technology. China and Europe mostly have used Selective Catalytic Reduction (SCR) with urea to meet the Euro IV diesel engine emission standard. In this study, two Euro IV busses with SCR were tested by using potable emission measurement system (PEMS) to assess NOx emissions associated with urban, suburban and freeway driving patterns. The results indicated that with the SCR system, the urea injection time for the entire driving period increased with higher vehicle speed. For freeway driving, the urea injection time covered 71%-83% of the driving period; the NOx emission factors from freeway driving were lower than those associated with urban and suburban driving. Unfortunately, the NOx emission factors were 2.6-2.8-, 2.3-2.7- and 2.2-2.3-fold higher than the Euro IV standard limits for urban, suburban and freeway driving, respectively; NOx emission factors (in g/km and g/(kW·h)) from the original vehicles (without SCR) were higher than their corresponding vehicles with SCR for suburban and freeway driving. Compared with the IVE model results, the measured NOx emission factors were 1.60-1.16-, 1.77-1.27-, 2.49-2.44-fold higher than the NOx predicted by the IVE model for urban and suburban driving, respectively. Thus, an adjustment of emission factors is needed to improve the estimation of Euro IV vehicle emissions in China. Copyright © 2013 Elsevier B.V. All rights reserved.

The challenge to NOx emission control for heavy-duty diesel vehicles in China

NASA Astrophysics Data System (ADS)

Wu, Y.; Zhang, S. J.; Li, M. L.; Ge, Y. S.; Shu, J. W.; Zhou, Y.; Xu, Y. Y.; Hu, J. N.; Liu, H.; Fu, L. X.; He, K. B.; Hao, J. M.

2012-10-01

China's new "Twelfth Five-Year Plan" set a target for total NOx emission reduction of 10% for the period of 2011-2015. Heavy-duty diesel vehicles (HDDVs) have been considered a major contributor to NOx emissions in China. Beijing initiated a comprehensive vehicle test program in 2008. This program included a sub-task for measuring on-road emission profiles of hundreds of HDDVs using portable emission measurement systems (PEMS). The major finding is that neither the on-road distance-specific (g km-1) nor brake-specific (g kWh-1) NOx emission factors for diesel buses and heavy-duty diesel trucks improved in most cases as emission standards became more stringent. For example, the average NOx emission factors for Euro II, Euro III and Euro IV buses are 11.3 ± 3.3 g km-1, 12.5 ± 1.3 g km-1, and 11.8 ± 2.0 g km-1, respectively. No statistically significant difference in NOx emission factors was observed between Euro II and III buses. Even for Euro IV buses equipped with SCR systems, the NOx emission factors are similar to Euro III buses. The data regarding real-time engine performance of Euro IV buses suggest the engine certification cycles did not reflect their real-world operating conditions. These new on-road test results indicate that previous estimates of total NOx emissions for HDDV fleet may be significantly underestimated. The new estimate in total NOx emissions for the Beijing HDDV fleet in 2009 is 37.0 Gg, an increase of 45% compared to the previous study. Further, we estimate that the total NOx emissions for the national HDDV fleet in 2009 are approximately 4.0 Tg, higher by 1.0 Tg (equivalent to 18% of total NOx emissions for vehicle fleet in 2009) than that estimated in the official report. This would also result in 4% increase in estimation of national anthropogenic NOx emissions. More effective control measures (such as promotion of CNG buses and a new in-use compliance testing program) are urged to secure the goal of total NOx mitigation for the HDDV fleet in the future.

Reduction of nitrogen oxides (NOx) by superalkalis

NASA Astrophysics Data System (ADS)

Srivastava, Ambrish Kumar

2018-03-01

NOx are major air pollutants, having negative impact on environment and consequently, human health. We propose here the single-electron reduction of NOx (x = 1, 2) using superalkalis. We study the interaction of NOx with FLi2, OLi3 and NLi4 superalkalis using density functional and single-point CCSD(T) calculations, which lead to stable superalkali-NOx ionic complexes with negatively charged NOx. This clearly reveals that the NOx can successfully be reduced to NOx- anion due to electron transfer from superalkalis. It has been also noticed that the size of superalkalis plays a crucial in the single-electron reduction of NOx.

The challenge to NOx emission control for heavy-duty diesel vehicles in China

NASA Astrophysics Data System (ADS)

Wu, Y.; Zhang, S. J.; Li, M. L.; Ge, Y. S.; Shu, J. W.; Zhou, Y.; Xu, Y. Y.; Hu, J. N.; Liu, H.; Fu, L. X.; He, K. B.; Hao, J. M.

2012-07-01

China's new "Twelfth Five-Year Plan" set a target for total NOx emission reduction of 10% for the period of 2011-2015. Heavy-duty diesel vehicles (HDDVs) have been considered a major contributor to NOx emissions in China. Beijing initiated a comprehensive vehicle test program in 2008. This program included a sub-task for measuring on-road emission profiles of hundreds of HDDVs using portable emission measurement systems (PEMS). The major finding is that neither the on-road distance-specific (g km -1) nor brake-specific (g kW h-1) NOx emission factors for diesel buses and heavy-duty diesel trucks improved in most cases as emission standards became more stringent. For example, the average NOx emission factors for Euro II, Euro III and Euro IV buses are 11.3±3.3 g km-1, 12.5± 1.3 g km-1, and 11.8±2.0 g km-1, respectively. No statistically significant difference in NOx emission factors was observed between Euro II and III buses. Even for Euro IV buses equipped with SCR systems, the NOx emission factors are similar to Euro III buses. The data regarding real-time engine performance of Euro IV buses suggest the engine certification cycles did not reflect their real-world operating conditions. These new on-road test results indicate that previous estimates of total NOx emissions for HDDV fleet may be significantly underestimated. The new estimate in total NOx emissions for the Beijing HDDV fleet in 2009 is 37.0 Gg, an increase of 45% compared to the previous study. Further, we estimate that the total NOx emissions for the national HDDV fleet in 2009 are approximately 4.0 Tg, higher by 1.0 Tg (equivalent to 18% of total NOx emissions for vehicle fleet in 2009) than that estimated in the official report. This would also result in 4% increase in estimation of national anthropogenic NOx emissions. More effective control measures (such as promotion of CNG buses and a new in-use compliance testing program) are urged to secure the goal of total NOxmitigation for the HDDV fleet in the future.

Experimental modeling of NOx and PM generation from combustion of various biodiesel blends for urban transport buses : research brief.

DOT National Transportation Integrated Search

2016-08-01

Although it is generally accepted : that biodiesel fuel contributes : to the reduction of pollutants, : biodiesel still needs more study : for better control of combustion emissions and engine performance. Biodiesel has very diverse : sources of feed...

Biofuels, vehicle emissions, and urban air quality.

PubMed

Wallington, Timothy J; Anderson, James E; Kurtz, Eric M; Tennison, Paul J

2016-07-18

Increased biofuel content in automotive fuels impacts vehicle tailpipe emissions via two mechanisms: fuel chemistry and engine calibration. Fuel chemistry effects are generally well recognized, while engine calibration effects are not. It is important that investigations of the impact of biofuels on vehicle emissions consider the impact of engine calibration effects and are conducted using vehicles designed to operate using such fuels. We report the results of emission measurements from a Ford F-350 fueled with either fossil diesel or a biodiesel surrogate (butyl nonanoate) and demonstrate the critical influence of engine calibration on NOx emissions. Using the production calibration the emissions of NOx were higher with the biodiesel fuel. Using an adjusted calibration (maintaining equivalent exhaust oxygen concentration to that of the fossil diesel at the same conditions by adjusting injected fuel quantities) the emissions of NOx were unchanged, or lower, with biodiesel fuel. For ethanol, a review of the literature data addressing the impact of ethanol blend levels (E0-E85) on emissions from gasoline light-duty vehicles in the U.S. is presented. The available data suggest that emissions of NOx, non-methane hydrocarbons, particulate matter (PM), and mobile source air toxics (compounds known, or suspected, to cause serious health impacts) from modern gasoline and diesel vehicles are not adversely affected by increased biofuel content over the range for which the vehicles are designed to operate. Future increases in biofuel content when accomplished in concert with changes in engine design and calibration for new vehicles should not result in problematic increases in emissions impacting urban air quality and may in fact facilitate future required emissions reductions. A systems perspective (fuel and vehicle) is needed to fully understand, and optimize, the benefits of biofuels when blended into gasoline and diesel.

Experimental clean combustor program, phase 2

NASA Technical Reports Server (NTRS)

Gleason, C. C.; Rogers, D. W.; Bahr, D. W.

1976-01-01

The primary objectives of this three-phase program are to develop technology for the design of advanced combustors with significantly lower pollutant emission levels than those of current combustors, and to demonstrate these pollutant emission reductions in CF6-50C engine tests. The purpose of the Phase 2 Program was to further develop the two most promising concepts identified in the Phase 1 Program, the double annular combustor and the radial/axial staged combustor, and to design a combustor and breadboard fuel splitter control for CF6-50 engine demonstration testing in the Phase 3 Program. Noise measurement and alternate fuels addendums to the basic program were conducted to obtain additional experimental data. Twenty-one full annular and fifty-two sector combustor configurations were evaluated. Both combustor types demonstrated the capability for significantly reducing pollutant emission levels. The most promising results were obtained with the double annular combustor. Rig test results corrected to CF-50C engine conditions produced EPA emission parameters for CO, HC, and NOX of 3.4, 0.4, and 4.5 respectively. These levels represent CO, HC, and NOX reductions of 69, 90, and 42 percent respectively from current combustor emission levels. The combustor also met smoke emission level requirements and development engine performance and installation requirements.

Lean burn natural gas fueled S.I. engine and exhaust emissions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Varde, K.S.; Patro, N.; Drouillard, K.

1995-12-31

An experimental study was undertaken to study exhaust emission from a lean-burn natural gas spark ignition engine. The possibility that such an engine may help to reduce exhaust emissions substantially by taking advantage of natural gas fuel properties, such as its antiknock properties and extended lean flammability limit compared to gasoline, was the main motivation behind the investigation. A four cylinder, automotive type spark ignition engine was used in the investigation. The engine was converted to operate on natural gas by replacing its fuel system with a gaseous carburetion system. A 3-way metal metrix catalytic converter was used in themore » engine exhaust system to reduce emission levels. The engine operated satisfactorily at an equivalence ratio as lean as 0.6, at all speeds and loads. As a result NOx emissions were significantly reduced. However, hydrocarbon emissions were high, particularly at very lean conditions and light loads. Most of these hydrocarbons were made up of methane with small concentrations of ethane and propane. Coefficient of variations in hydrocarbons were generally high at very lean operating conditions and light loads, but decreased with increasing equivalence ratio and engine speed. Methane concentrations in the engine exhaust decreased with increasing load and equivalence ratio. At lean air-to-fuel ratios and light loads oxidation of methane in the catalyst was substantially limited and no NOx reduction was achieved. In addition, the proportion of nitric oxide in oxides of nitrogen increased with increasing amount of NOx in the engine exhaust. A major problem encountered in the study was the inability of the fuel system to maintain near constant air-to-fuel ratios at steady operating conditions.« less

Physical and Chemical Processes in Flames

DTIC Science & Technology

2010-02-15

Results: Use of comprehensively validated reduced chemical kinetic mechanism allows realistic description of methane oxidation chemistry with NOx ...PERFORMING ORGANIZATION REPORT NUMBER Department of Mechanical and Aerospace Engineering Princeton University Princeton, NJ 08544... mechanism reduction; skeletal mechanism ; CO/H2 oxidation; ethylene oxidation; heptane oxidation; directed relation graph; high-pressure combustion

High NO2/NOx emissions downstream of the catalytic diesel particulate filter: An influencing factor study.

PubMed

He, Chao; Li, Jiaqiang; Ma, Zhilei; Tan, Jianwei; Zhao, Longqing

2015-09-01

Diesel vehicles are responsible for most of the traffic-related nitrogen oxide (NOx) emissions, including nitric oxide (NO) and nitrogen dioxide (NO2). The use of after-treatment devices increases the risk of high NO2/NOx emissions from diesel engines. In order to investigate the factors influencing NO2/NOx emissions, an emission experiment was carried out on a high pressure common-rail, turbocharged diesel engine with a catalytic diesel particulate filter (CDPF). NO2 was measured by a non-dispersive ultraviolet analyzer with raw exhaust sampling. The experimental results show that the NO2/NOx ratios downstream of the CDPF range around 20%-83%, which are significantly higher than those upstream of the CDPF. The exhaust temperature is a decisive factor influencing the NO2/NOx emissions. The maximum NO2/NOx emission appears at the exhaust temperature of 350°C. The space velocity, engine-out PM/NOx ratio (mass based) and CO conversion ratio are secondary factors. At a constant exhaust temperature, the NO2/NOx emissions decreased with increasing space velocity and engine-out PM/NOx ratio. When the CO conversion ratios range from 80% to 90%, the NO2/NOx emissions remain at a high level. Copyright © 2015. Published by Elsevier B.V.

Impact de l'utilisation des strategies d'injection multiple et de biodiesel sur un moteur diesel a rampe commune d'injection

NASA Astrophysics Data System (ADS)

Plamondon, Etienne

Using biodiesel/diesel fuel blends and multiple injection strategies in diesel engines have shown promising results in improving the trade-off relationship between nitrous oxides and particulate matters, but their effects are still not completely understood. In this context, this thesis focuses on the characterization of the multiple injection strategies and biodiesel impacts on pollutant emissions, performances and injection system behavior. To reach this goal, an experimental campaign on a diesel engine was performed and a model simulating the injection process was developed. The engine tests at low load with pilot injection allowed the reduction of NOx emissions up to 27% and those of PM up to 22.3% compared to single injection, provided that a precise tuning of the injection parameters was previously realized. This simultaneous reduction is explained by the reduction of the premixed combustion phase and injected fuel quantity during principal injection when a pilot injection is used. With triple injection for the tested engine load, the post-injection did not result in PM reduction since it contributes by itself to the PM production while the preinjection occurred too soon to burn conveniently and caused perturbations in the injection system as well. Using B20 blend in single injection caused a PM increase and a NOx reduction which might be explained by the poorer fuel atomization. However, pilot injection with B20 allowed to get a simultaneous reduction of NOx and PM, as observed with diesel. An injection simulation model was also developed and experimentally validated for different injection pressures as well as different energizing times and dwell times. When comparing the use of biodiesel with diesel, simulation showed that there was a critical energizing time for which both fuels yielded the same injection duration. For shorter energizing times, the biodiesel injection duration was shorter than for diesel, while longer energizing times presented the opposite behavior. The injection duration for the different blends falls between the pure-fuel situations. The use of constant properties (density, viscosity) and constant discharge coefficient showed no major loss in the precision of the flow-rate estimation, but revealed a great gain in calculus time. The use of pressure dependent bulk modulus and fluctuating injection pressure proved to be essential in order to have no drastic changes in the final predictions. Finally, the proposed model relevance in a case of engine testing was demonstrated with multiple injection strategies as well as with biodiesel since it allows a precise adjustment of the injection parameters while considering the dynamic effects caused by the injection. Keywords : Diesel engine, multiple injection, biodiesel, pollutant emission, heat release, mathematical model, injection simulation.

A Comparative Study of Almond Biodiesel-Diesel Blends for Diesel Engine in Terms of Performance and Emissions

PubMed Central

Alnefaie, Khaled A.

2015-01-01

This paper investigates the opportunity of using almond oil as a renewable and alternative fuel source. Different fuel blends containing 10, 30, and 50% almond biodiesel (B10, B30, and B50) with diesel fuel (B0) were prepared and the influence of these blends on emissions and some performance parameters under various load conditions were inspected using a diesel engine. Measured engine performance parameters have generally shown a slight increase in exhaust gas temperature and in brake specific fuel consumption and a slight decrease in brake thermal efficiency. Gases investigated were carbon monoxide (CO) and oxides of nitrogen (NOx). Furthermore, the concentration of the total particulate and the unburned fuel emissions in the exhaust gas were tested. A blend of almond biodiesel with diesel fuel gradually reduced the engine CO and total particulate emissions compared to diesel fuel alone. This reduction increased with more almond biodiesel blended into the fuel. Finally, a slight increase in engine NOx using blends of almond biodiesel was measured. PMID:25874218

Evaluation of Fuel-Borne Sodium Effects on a DOC-DPF-SCR Heavy-Duty Engine Emission Control System: Simulation of Full-Useful Life

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lance, Michael; Wereszczak, Andrew; Toops, Todd J.

2016-04-05

For renewable fuels to displace petroleum, they must be compatible with emissions control devices. Pure biodiesel contains up to 5 ppm Na + K and 5 ppm Ca + Mg metals, which have the potential to degrade diesel emissions control systems. This study aims to address these concerns, identify deactivation mechanisms, and determine if a lower limit is needed. Accelerated aging of a production exhaust system was conducted on an engine test stand over 1,001 hr using B20 doped with 14 ppm Na. During the study, oxides of nitrogen (NOx) emissions exceeded the engine certification limit of 0.33 g/bhp-hr beforemore » the 435,000-mile requirement. Replacing aged diesel oxidation catalyst (DOC), diesel particulate filter (DPF), and selective catalytic reduction (SCR) devices with new degreened parts showed that each device contributed equally to the NOx increase. Following this systems-based evaluation, a detailed investigation of the individual components was completed. Na was determined to have minimal impact on DOC activity. For this system, it is estimated that B20-Na resulted in 50% more ash into the DPF. However, the Na did not diffuse into the cordierite DPF nor degrade its mechanical properties. The SCR degradation was found to be caused by a small amount of precious group metals contamination that increased ammonia oxidation, and lowered NOx reduction. Therefore, it was determined that the primary effect of Na in this study is through increased ash in the DPF rather than deactivation of the catalytic activity.« less

Nox reduction system utilizing pulsed hydrocarbon injection

DOEpatents

Brusasco, Raymond M.; Penetrante, Bernardino M.; Vogtlin, George E.; Merritt, Bernard T.

2001-01-01

Hydrocarbon co-reductants, such as diesel fuel, are added by pulsed injection to internal combustion engine exhaust to reduce exhaust NO.sub.x to N.sub.2 in the presence of a catalyst. Exhaust NO.sub.x reduction of at least 50% in the emissions is achieved with the addition of less than 5% fuel as a source of the hydrocarbon co-reductants. By means of pulsing the hydrocarbon flow, the amount of pulsed hydrocarbon vapor (itself a pollutant) can be minimized relative to the amount of NO.sub.x species removed.

40 CFR 86.004-15 - NOX plus NMHC and particulate averaging, trading, and banking for heavy-duty engines.

Code of Federal Regulations, 2012 CFR

2012-07-01

... averaging, trading, and banking for heavy-duty engines. 86.004-15 Section 86.004-15 Protection of... Heavy-Duty Vehicles § 86.004-15 NOX plus NMHC and particulate averaging, trading, and banking for heavy-duty engines. (a)(1) Heavy-duty engines eligible for NOX plus NMHC and particulate averaging, trading...

Hybrid vehicle system studies and optimized hydrogen engine design

NASA Astrophysics Data System (ADS)

Smith, J. R.; Aceves, S.

1995-04-01

We have done system studies of series hydrogen hybrid automobiles that approach the PNGV design goal of 34 km/liter (80 mpg), for 384 km (240 mi) and 608 km (380 mi) ranges. Our results indicate that such a vehicle appears feasible using an optimized hydrogen engine. We have evaluated the impact of various on-board storage options on fuel economy. Experiments in an available engine at the Sandia CRF demonstrated NO(x) emissions of 10 to 20 ppM at an equivalence ratio of 0.4, rising to about 500 ppm at 0.5 equivalence ratio using neat hydrogen. Hybrid simulation studies indicate that exhaust NO(x) concentrations must be less than 180 ppM to meet the 0.2 g/mile ULEV or Federal Tier II emissions regulations. LLNL has designed and fabricated a first generation optimized hydrogen engine head for use on an existing Onan engine. This head features 15:1 compression ratio, dual ignition, water cooling, two valves and open quiescent combustion chamber to minimize heat transfer losses. Initial testing shows promise of achieving an indicated efficiency of nearly 50% and emissions of less than 100 ppM NO(x). Hydrocarbons and CO are to be measured, but are expected to be very low since their only source is engine lubricating oil. A successful friction reduction program on the Onan engine should result in a brake thermal efficiency of about 42% compared to today's gasoline engines of 32%. Based on system studies requirements, the next generation engine will be about 2 liter displacement and is projected to achieve 46% brake thermal efficiency with outputs of 15 kW for cruise and 40 kW for hill climb.

Real-time CO2 sensor for the optimal control of electronic EGR system

NASA Astrophysics Data System (ADS)

Kim, Gwang-jung; Choi, Byungchul; Choi, Inchul

2013-12-01

In modern diesel engines, EGR (Exhaust Gas Recirculation) is an important technique used in nitrogen oxide (NOx) emission reduction. This paper describes the development and experimental results of a fiber-optical sensor using a 2.7 μm wavelength absorption to quantify the simultaneous CO2 concentration which is the primary variable of EGR rate (CO2 in the exhaust gas versus CO2 in the intake gas, %). A real-time laser absorption method was developed using a DFB (distributed feedback) diode laser and waveguide to make optimal design and control of electronic EGR system required for `Euro-6' and `Tier 4 Final' NOx emission regulations. While EGR is effective to reduce NOx significantly, the amount of HC and CO is increased in the exhaust gas if EGR rate is not controlled based on driving conditions. Therefore, it is important to recirculate an appropriate amount of exhaust gas in the operation condition generating high volume of NOx. In this study, we evaluated basic characteristics and functions of our optical sensor and studied basically in order to find out optimal design condition. We demonstrated CO2 measurement speed, accuracy and linearity as making a condition similar to real engine through the bench-scale experiment.

Experimental investigation on NOx and green house gas emissions from a marine auxiliary diesel engine using ultralow sulfur light fuel.

PubMed

Geng, Peng; Tan, Qinming; Zhang, Chunhui; Wei, Lijiang; He, Xianzhong; Cao, Erming; Jiang, Kai

2016-12-01

In recent years, marine auxiliary diesel engine has been widely used to produce electricity in the large ocean-going ship. One of the main technical challenges for ocean-going ship is to reduce pollutant emissions from marine auxiliary diesel engine and to meet the criteria of disposal on ships pollutants of IMO (International Maritime Organization). Different technical changes have been introduced in marine auxiliary diesel engine to apply clean fuels to reduce pollutant emissions. The ultralow sulfur light fuel will be applied in diesel engine for emission reductions in China. This study is aimed to investigate the impact of fuel (ultralow sulfur light fuel) on the combustion characteristic, NOx and green house gas emissions in a marine auxiliary diesel engine, under the 50%-90% engine speeds and the 25%-100% engine torques. The experimental results show that, in the marine auxiliary diesel engine, the cylinder pressure and peak heat release rate increase slightly with the increase of engine torques, while the ignition advances and combustion duration become longer. With the increases of the engine speed and torque, the fuel consumption decreases significantly, while the temperature of the exhaust manifold increases. The NOx emissions increase significantly with the increases of the engine speed and torque. The NO emission increases with the increases of the engine speed and torque, while the NO 2 emission decreases. Meanwhile, the ratio of NO 2 and NO is about 1:1 when the diesel engine operated in the low speed and load, while the ratio increases significantly with the increases of engine speed and torque, due to the increase of the cylinder temperature in the diffusive combustion mode. Moreover, the CO 2 emission increases with the increases of engine speed and torque by the use of ultralow sulfur light fuel. Copyright © 2016. Published by Elsevier B.V.

40 CFR Appendix I to Part 1054 - Summary of Previous Emission Standards

Code of Federal Regulations, 2014 CFR

2014-07-01

... Engines (g/kW-hr) a Engine displacement class HC NOX CO Class III 295 5.36 805 Class IV 241 5.36 805 Class...—Phase 2 Emission Standards for Handheld Engines (g/kW-hr) a Engine displacement class HC+NOX CO Class...-hr) a Engine displacement class HC+NOX CO Class I 16.1 519 Class II 13.4 519 a Phase 1 standards are...

40 CFR Appendix I to Part 1054 - Summary of Previous Emission Standards

Code of Federal Regulations, 2012 CFR

2012-07-01

... Engines (g/kW-hr) a Engine displacement class HC NOX CO Class III 295 5.36 805 Class IV 241 5.36 805 Class...—Phase 2 Emission Standards for Handheld Engines (g/kW-hr) a Engine displacement class HC+NOX CO Class...-hr) a Engine displacement class HC+NOX CO Class I 16.1 519 Class II 13.4 519 a Phase 1 standards are...

40 CFR Appendix I to Part 1054 - Summary of Previous Emission Standards

Code of Federal Regulations, 2013 CFR

2013-07-01

... Engines (g/kW-hr) a Engine displacement class HC NOX CO Class III 295 5.36 805 Class IV 241 5.36 805 Class...—Phase 2 Emission Standards for Handheld Engines (g/kW-hr) a Engine displacement class HC+NOX CO Class...-hr) a Engine displacement class HC+NOX CO Class I 16.1 519 Class II 13.4 519 a Phase 1 standards are...

40 CFR Appendix I to Part 1054 - Summary of Previous Emission Standards

Code of Federal Regulations, 2010 CFR

2010-07-01

... Engines (g/kW-hr) a Engine displacement class HC NOX CO Class III 295 5.36 805 Class IV 241 5.36 805 Class...—Phase 2 Emission Standards for Handheld Engines (g/kW-hr) a Engine displacement class HC+NOX CO Class...-hr) a Engine displacement class HC+NOX CO Class I 16.1 519 Class II 13.4 519 a Phase 1 standards are...

40 CFR Appendix I to Part 1054 - Summary of Previous Emission Standards

Code of Federal Regulations, 2011 CFR

2011-07-01

... Engines (g/kW-hr) a Engine displacement class HC NOX CO Class III 295 5.36 805 Class IV 241 5.36 805 Class...—Phase 2 Emission Standards for Handheld Engines (g/kW-hr) a Engine displacement class HC+NOX CO Class...-hr) a Engine displacement class HC+NOX CO Class I 16.1 519 Class II 13.4 519 a Phase 1 standards are...

Tuneable diode laser spectroscopy correction factor investigation on ammonia measurement

NASA Astrophysics Data System (ADS)

Li, Nilton; El-Hamalawi, Ashraf; Baxter, Jim; Barrett, Richard; Wheatley, Andrew

2018-01-01

Current diesel engine aftertreatment systems, such as Selective Catalyst Reduction (SCR) use ammonia (NH3) to reduce Nitrogen Oxides (NOx) into Nitrogen (N2) and water (H2O). However, if the reaction between NH3 and NOx is unbalanced, it can lead either NH3 or NOx being released into the environment. As NH3 is classified as a dangerous compound in the environment, its accurate measurement is essential. Tuneable Diode Laser (TDL) spectroscopy is one of the methods used to measure raw emissions inside engine exhaust pipes, especially NH3. This instrument requires a real-time exhaust temperature, pressure and other interference compounds in order to adjust itself to reduce the error in NH3 readings. Most researchers believed that exhaust temperature and pressure were the most influential factors in TDL when measuring NH3 inside exhaust pipes. The aim of this paper was to quantify these interference effects on TDL when undertaking NH3 measurement. Surprisingly, the results show that pressure was the least influential factor when compared to temperature, H2O, CO2 and O2 when undertaking NH3 measurement using TDL.

Laser Absorption Measurements of Equivalence Ratios Studied Along With Their Coupling to Pressure Fluctuations in Lean Premixed Prevaporized (LPP) Combustion

NASA Technical Reports Server (NTRS)

Nguyen, Quang-Viet

2001-01-01

Concerns about damaging the Earth's ozone layer as a result of high levels of nitrogen oxides (known collectively as NOx) from high-altitude, high-speed aircraft have prompted the study of lean premixed prevaporized (LPP) combustion in aircraft engines. LPP combustion reduces NOx emissions principally by reducing the peak flame temperatures inside an engine. Recent advances in LPP technologies have realized exceptional reductions in pollutant emissions (single-digit ppm NOx for example). However, LPP combustion also presents major challenges: combustion instability and dynamic coupling effects between fluctuations in heat-release rate, dynamic pressure, and fuel pressure. These challenges are formidable and can literally shake an engine apart if uncontrolled. To better understand this phenomenon so that it can be controlled, we obtained real-time laser absorption measurements of the fuel vapor concentration (and equivalence ratio) simultaneously with the dynamic pressure, flame luminosity, and time-averaged gaseous emissions measurements in a research-type jet-A-fueled LPP combustor. The measurements were obtained in NASA Glenn Research Center's CE-5B optically accessible flame tube facility. The CE-5B facility provides inlet air temperatures and pressures similar to the actual operating conditions of real aircraft engines. The laser absorption measurements were performed using an infrared 3.39 micron HeNe laser in conjunction with a visible HeNe laser for liquid droplet scattering compensation.

Assessment of the Performance Potential of Advanced Subsonic Transport Concepts for NASA's Environmentally Responsible Aviation Project

NASA Technical Reports Server (NTRS)

Nickol, Craig L.; Haller, William J.

2016-01-01

NASA's Environmentally Responsible Aviation (ERA) project has matured technologies to enable simultaneous reductions in fuel burn, noise, and nitrogen oxide (NOx) emissions for future subsonic commercial transport aircraft. The fuel burn reduction target was a 50% reduction in block fuel burn (relative to a 2005 best-in-class baseline aircraft), utilizing technologies with an estimated Technology Readiness Level (TRL) of 4-6 by 2020. Progress towards this fuel burn reduction target was measured through the conceptual design and analysis of advanced subsonic commercial transport concepts spanning vehicle size classes from regional jet (98 passengers) to very large twin aisle size (400 passengers). Both conventional tube-and-wing (T+W) concepts and unconventional (over-wing-nacelle (OWN), hybrid wing body (HWB), mid-fuselage nacelle (MFN)) concepts were developed. A set of propulsion and airframe technologies were defined and integrated onto these advanced concepts which were then sized to meet the baseline mission requirements. Block fuel burn performance was then estimated, resulting in reductions relative to the 2005 best-in-class baseline performance ranging from 39% to 49%. The advanced single-aisle and large twin aisle T+W concepts had reductions of 43% and 41%, respectively, relative to the 737-800 and 777-200LR aircraft. The single-aisle OWN concept and the large twin aisle class HWB concept had reductions of 45% and 47%, respectively. In addition to their estimated fuel burn reduction performance, these unconventional concepts have the potential to provide significant noise reductions due, in part, to engine shielding provided by the airframe. Finally, all of the advanced concepts also have the potential for significant NOx emissions reductions due to the use of advanced combustor technology. Noise and NOx emissions reduction estimates were also generated for these concepts as part of the ERA project.

Research Data Acquired in World-Class, 60-atm Subsonic Combustion Rig

NASA Technical Reports Server (NTRS)

Lee, Chi-Ming; Wey, Changlie

1999-01-01

NASA Lewis Research Center's new, world-class, 60-atmosphere (atm) combustor research facility, the Advanced Subsonic Combustion Rig (ASCR), is in operation and producing highly unique research data. Specifically, data were acquired at high pressures and temperatures representative of future subsonic engines from a fundamental flametube configuration with an advanced fuel injector. The data acquired include exhaust emissions as well as pressure and temperature distributions. Results to date represent an improved understanding of nitrous oxide (NOx) formation at high pressures and temperatures and include an NOx emissions reduction greater than 70 percent with an advanced fuel injector at operating pressures to 800 pounds per square inch absolute (psia). ASCR research is an integral part of the Advanced Subsonic Technology (AST) Propulsion Program. This program is developing critical low-emission combustion technology that will result in the next generation of gas turbine engines producing 50 to 70 percent less NOx emissions in comparison to 1996 International Civil Aviation Organization (ICAO) limits. The results to date indicate that the AST low-emission combustor goals of reducing NOx emissions by 50 to 70 percent are feasible. U.S. gas turbine manufacturers have started testing the low-emissions combustors at the ASCR. This collaborative testing will enable the industry to develop low-emission combustors at the high pressure and temperature conditions of future subsonic engines. The first stage of the flametube testing has been implemented. Four GE Aircraft Engines low-emissions fuel injector concepts, three Pratt & Whitney concepts, and two Allison concepts have been tested at Lewis ASCR facility. Subsequently, the flametube was removed from the test stand, and the sector combustor was installed. The testing of low emissions sector has begun. Low-emission combustors developed as a result of ASCR research will enable U.S. engine manufacturers to compete on a worldwide basis by producing environmentally acceptable commercial engines.

Plasma-assisted combustion technology for NOx reduction in industrial burners.

PubMed

Lee, Dae Hoon; Kim, Kwan-Tae; Kang, Hee Seok; Song, Young-Hoon; Park, Jae Eon

2013-10-01

Stronger regulations on nitrogen oxide (NOx) production have recently promoted the creation of a diverse array of technologies for NOx reduction, particularly within the combustion process, where reduction is least expensive. In this paper, we discuss a new combustion technology that can reduce NOx emissions within industrial burners to single-digit parts per million levels without employing exhaust gas recirculation or other NOx reduction mechanisms. This new technology uses a simple modification of commercial burners, such that they are able to perform plasma-assisted staged combustion without altering the outer configuration of the commercial reference burner. We embedded the first-stage combustor within the head of the commercial reference burner, where it operated as a reformer that could host a partial oxidation process, producing hydrogen-rich reformate or synthesis gas product. The resulting hydrogen-rich flow then ignited and stabilized the combustion flame apart from the burner rim. Ultimately, the enhanced mixing and removal of hot spots with a widened flame area acted as the main mechanisms of NOx reduction. Because this plasma burner acted as a low NOx burner and was able to reduce NOx by more than half compared to the commercial reference burner, this methodology offers important cost-effective possibilities for NOx reduction in industrial applications.

A novel additive for the reduction of acid gases and NO(x) in municipal waste incinerator flue gas.

PubMed

Hall, William J; Williams, Paul T

2006-08-01

The reduction of SO2, HCl, and NO(x) concentrations using calcium magnesium acetate (CMA) as a novel sorbent in a simulated municipal waste incinerator flue gas was investigated. The reduction of individual SO2, HCl, and NO(x) concentrations was tested at 850 degrees C and it was found that CMA could reduce the SO2 concentration by 74%, HCl concentration by 64%, or NO(x) concentration by 94%. It was observed that individual SO2 or HCl capture increased with increasing initial oxygen concentration in the reacting gas or increasing sorbent input. NO(x) reduction decreased with increasing initial oxygen concentration in the reacting gas. The simultaneous reduction of SO2, HCl, and NO(x) concentrations by CMA was also investigated. It was found that CMA could simultaneously capture 60% SO2 and 61% HCl and reduce NO(x) concentrations by 26%, when the initial oxygen concentration in the reacting gas was 4%. During the simultaneous reduction of SO2, HCl, and NO(x), it was noted that as the initial oxygen concentration in the reacting gas increased, the efficiency of SO2 capture increased too, but the efficiency of HCl capture and the efficiency of NO(x) destruction decreased.

NOx emissions in China: historical trends and future perspectives

NASA Astrophysics Data System (ADS)

Zhao, B.; Wang, S. X.; Liu, H.; Xu, J. Y.; Fu, K.; Klimont, Z.; Hao, J. M.; He, K. B.; Cofala, J.; Amann, M.

2013-10-01

Nitrogen oxides (NOx) are key pollutants for the improvement of ambient air quality. Within this study we estimated the historical NOx emissions in China for the period 1995-2010, and calculated future NOx emissions every five years until 2030 under six emission scenarios. Driven by the fast growth of energy consumption, we estimate the NOx emissions in China increased rapidly from 11.0 Mt in 1995 to 26.1 Mt in 2010. Power plants, industry and transportation were major sources of NOx emissions, accounting for 28.4%, 34.0%, and 25.4% of the total NOx emissions in 2010, respectively. Two energy scenarios, a business as usual scenario (BAU) and an alternative policy scenario (PC), were developed to project future energy consumption. In 2030, total energy consumption is projected to increase by 64% and 27% from 2010 level respectively. Three sets of end-of-pipe pollution control measures, including baseline, progressive, and stringent control case, were developed for each energy scenario, thereby constituting six emission scenarios. By 2030, the total NOx emissions are projected to increase (compared to 2010) by 36% in the baseline while policy cases result in reduction up to 61% in the most ambitious case with stringent control measures. More than a third of the reduction achieved by 2030 between least and most ambitious scenario comes from power sector, and more than half is distributed equally between industry and transportation sectors. Selective catalytic reduction dominates the NOx emission reductions in power plants, while life style changes, control measures for industrial boilers and cement production are major contributors to reductions in industry. Timely enforcement of legislation on heavy-duty vehicles would contribute significantly to NOx emission reductions. About 30% of the NOx emission reduction in 2020 and 40% of the NOx emission reduction in 2030 could be treated as the ancillary benefit of energy conservation. Sensitivity analysis was conducted to explore the impact of key factors on future emissions.

40 CFR 86.007-15 - NOX and particulate averaging, trading, and banking for heavy-duty engines.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 18 2011-07-01 2011-07-01 false NOX and particulate averaging, trading... § 86.007-15 NOX and particulate averaging, trading, and banking for heavy-duty engines. Section 86.007... engines may participate in an NMHC averaging, banking and trading program to show compliance with the...

FreedomCAR - Aftertreatment Subsystem Development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lisa A. Prentiss

2005-09-30

The primary objective of this program was to develop generic aftertreatment technologies applicable for LDV and LDT engines ranging from 55 kW to 200kW, to develop an optimized and integrated aftertreatment system for a LDT (Light Duty Truck) type vehicle, and to demonstrate the technology which will enable light duty diesel engines to meet Federal Tier II regulation with minimum impact on fuel economy. Specifically, the development targets for emissions reduction and fuel injection penalty are given below: (1) NOx conversion efficiency > 90% (hot), > 84% (combined); (2) PM conversion efficiency > 90% (hot), > 84% (combined); (3) Fuelmore » penalty over FTP-75 Less than 5%; and (4) Fuel penalty at Cruise condition Less than 3%. Development of cost-effective, highly efficient diesel exhaust aftertreatment systems in combination with very low engine out emission combustion development are essential elements for realization of Federal Tier II emission standards for Light Duty Trucks and Vehicles. Evaluation of several aftertreatment technologies was completed as part of this program. A combination of Diesel Oxidation Catalyst, NOx Adsorbing Catalyst and Catalyzed Soot Filter was found to provide the levels of conversion efficiency required to achieve the emission targets. While early systems required relatively large catalyst volumes, external dosing, sulfur traps, full bypass configurations and high levels of Platinum metals; the final system is a compact, scalable, flow-through, fully-integrated and engine-managed aftertreatment system capable of commercial application for Light Duty Vehicles and Trucks. NOx adsorber/particulate filter technology is particularly attractive for Light Duty applications due to the lower exhaust flow and temperature requirements as compared to Heavy Duty engines. Despite these strong positive aspects, NOx Adsorbers are challenged by their regeneration requirements and susceptibility to sulfur poisoning and thermal degradation. Capability was developed to regenerate the NOx Adsorber for NOx and SOx as well as the Particulate Filter for soot. This system was fully integrated into a truck and evaluated over the chassis dynamometer for emissions capability and in real-world winter field testing. Durability of the system was evaluated over a variety of accelerated and real-time dynamometer tests. Excellent NOx and PM conversion efficiency was demonstrated, even following 3000 hrs of endurance testing. Unregulated emissions emitted by the system were evaluated as was the fuel penalty associated with the DeNOx and DeSOx regeneration processes. In the final evaluation, the system demonstrated 90% NOx conversion and 99% PM conversion at a 6% fuel penalty over the FTP-75 test cycle. While target fuel penalty levels were demonstrated using full-bypass configuration systems, the cost associated with those systems was prohibitively high and would preclude successful commercialization of the technology. Although the flow-through configuration fell 1% short of the 5% fuel penalty target, the cost of this configuration is such that commercial application is feasible. Cost drivers for the final system configuration were identified and demonstrate areas where future development areas could focus.« less

Regulated and unregulated emissions from modern 2010 emissions-compliant heavy-duty on-highway diesel engines.

PubMed

Khalek, Imad A; Blanks, Matthew G; Merritt, Patrick M; Zielinska, Barbara

2015-08-01

The U.S. Environmental Protection Agency (EPA) established strict regulations for highway diesel engine exhaust emissions of particulate matter (PM) and nitrogen oxides (NOx) to aid in meeting the National Ambient Air Quality Standards. The emission standards were phased in with stringent standards for 2007 model year (MY) heavy-duty engines (HDEs), and even more stringent NOX standards for 2010 and later model years. The Health Effects Institute, in cooperation with the Coordinating Research Council, funded by government and the private sector, designed and conducted a research program, the Advanced Collaborative Emission Study (ACES), with multiple objectives, including detailed characterization of the emissions from both 2007- and 2010-compliant engines. The results from emission testing of 2007-compliant engines have already been reported in a previous publication. This paper reports the emissions testing results for three heavy-duty 2010-compliant engines intended for on-highway use. These engines were equipped with an exhaust diesel oxidation catalyst (DOC), high-efficiency catalyzed diesel particle filter (DPF), urea-based selective catalytic reduction catalyst (SCR), and ammonia slip catalyst (AMOX), and were fueled with ultra-low-sulfur diesel fuel (~6.5 ppm sulfur). Average regulated and unregulated emissions of more than 780 chemical species were characterized in engine exhaust under transient engine operation using the Federal Test Procedure cycle and a 16-hr duty cycle representing a wide dynamic range of real-world engine operation. The 2010 engines' regulated emissions of PM, NOX, nonmethane hydrocarbons, and carbon monoxide were all well below the EPA 2010 emission standards. Moreover, the unregulated emissions of polycyclic aromatic hydrocarbons (PAHs), nitroPAHs, hopanes and steranes, alcohols and organic acids, alkanes, carbonyls, dioxins and furans, inorganic ions, metals and elements, elemental carbon, and particle number were substantially (90 to >99%) lower than pre-2007-technology engine emissions, and also substantially (46 to >99%) lower than the 2007-technology engine emissions characterized in the previous study.

Impacts of a Nanosized Ceria Additive on Diesel Engine Emissions of Particulate and Gaseous Pollutants

PubMed Central

Zhang, Junfeng; Nazarenko, Yevgen; Zhang, Lin; Calderon, Leonardo; Lee, Ki-Bum; Garfunkel, Eric; Schwander, Stephan; Tetley, Teresa D.; Chung, Kian Fan; Porter, Alexandra E.; Ryan, Mary; Kipen, Howard; Lioy, Paul J.; Mainelis, Gediminas

2014-01-01

Fuel additives incorporating nanosized ceria have been increasingly used in diesel engines as combustion promoters. However, few studies have assessed the impact of these nanotechnology-based additives on pollutant emissions. Here, we systematically compare emission rates of particulate and gaseous pollutants from a single-cylinder, four-cycle diesel engine using fuel mixes containing nanoceria of varying concentrations. The test fuels were made by adding different amounts of a commercial fuel additive Envirox into an ultralow-sulfur diesel fuel at 0 (base fuel), 0.1-, 1-, and 10-fold the manufacturer-recommended concentration of 0.5 mL Envirox per liter of fuel. The addition of Envirox resulted in ceria-concentration-dependent emission reductions of CO2, CO, total particulate mass, formaldehyde, acetaldehyde, acrolein, and several polycyclic aromatic hydrocarbons. These reductions at the manufacturer-recommended doping concentration, however, were accompanied by a substantial increase of certain other air pollutants, specifically the number of ultrafine particles (+32%), NOx (+9.3%), and the particle-phase benzo[a]pyrene toxic equivalence quotient (+35%). Increasing fuel ceria concentrations also led to decreases in the size of emitted particles. Given health concerns related to ultrafine particles and NOx, our findings call for additional studies to further evaluate health risks associated with the use of nanoceria additives in various engines under various operating conditions. PMID:24144266

Engine performance and exhaust emission analysis of a single cylinder diesel engine fuelled with water-diesel emulsion fuel blended with manganese metal additives

NASA Astrophysics Data System (ADS)

Muhsin Ithnin, Ahmad; Jazair Yahya, Wira; Baun Fletcher, Jasmine; Kadir, Hasannuddin Abd

2017-10-01

Water-in-diesel emulsion fuel (W/D) is one of the alternative fuels that capable to reduce the exhaust emission of diesel engine significantly especially the nitrogen oxides (NOx) and particulate matter (PM). However, the usage of W/D emulsion fuels contributed to higher CO emissions. Supplementing metal additive into the fuel is the alternate way to reduce the CO emissions and improve performance. The present paper investigates the effect of using W/D blended with organic based manganese metal additives on the diesel engine performance and exhaust emission. The test were carried out by preparing and analysing the results observed from five different tested fuel which were D2, emulsion fuel (E10: 89% D2, 10% - water, 1% - surfactant), E10Mn100, E10Mn150, E10Mn200. Organic based Manganese (100ppm, 150ppm, 200ppm) used as the additive in the three samples of the experiments. E10Mn200 achieved the maximum reduction of BSFC up to 13.66% and has the highest exhaust gas temperature. Whereas, E10Mn150 achieved the highest reduction of CO by 14.67%, and slightly increased of NOx emissions as compared to other emulsion fuels. Organic based manganese which act as catalyst promotes improvement of the emulsion fuel performance and reduced the harmful emissions discharged.

A particle filter for ammonia coverage ratio and input simultaneous estimations in Diesel-engine SCR system.

PubMed

Sun, Kangfeng; Ji, Fenzhu; Yan, Xiaoyu; Jiang, Kai; Yang, Shichun

2018-01-01

As NOx emissions legislation for Diesel-engines is becoming more stringent than ever before, an aftertreatment system has been widely used in many countries. Specifically, to reduce the NOx emissions, a selective catalytic reduction(SCR) system has become one of the most promising techniques for Diesel-engine vehicle applications. In the SCR system, input ammonia concentration and ammonia coverage ratio are regarded as essential states in the control-oriental model. Currently, an ammonia sensor placed before the SCR Can is a good strategy for the input ammonia concentration value. However, physical sensor would increase the SCR system cost and the ammonia coverage ratio information cannot be directly measured by physical sensor. Aiming to tackle this problem, an observer based on particle filter(PF) is investigated to estimate the input ammonia concentration and ammonia coverage ratio. Simulation results through the experimentally-validated full vehicle simulator cX-Emission show that the performance of observer based on PF is outstanding, and the estimation error is very small.

A particle filter for ammonia coverage ratio and input simultaneous estimations in Diesel-engine SCR system

PubMed Central

Ji, Fenzhu; Yan, Xiaoyu; Jiang, Kai

2018-01-01

As NOx emissions legislation for Diesel-engines is becoming more stringent than ever before, an aftertreatment system has been widely used in many countries. Specifically, to reduce the NOx emissions, a selective catalytic reduction(SCR) system has become one of the most promising techniques for Diesel-engine vehicle applications. In the SCR system, input ammonia concentration and ammonia coverage ratio are regarded as essential states in the control-oriental model. Currently, an ammonia sensor placed before the SCR Can is a good strategy for the input ammonia concentration value. However, physical sensor would increase the SCR system cost and the ammonia coverage ratio information cannot be directly measured by physical sensor. Aiming to tackle this problem, an observer based on particle filter(PF) is investigated to estimate the input ammonia concentration and ammonia coverage ratio. Simulation results through the experimentally-validated full vehicle simulator cX-Emission show that the performance of observer based on PF is outstanding, and the estimation error is very small. PMID:29408924

Optimization of suitable ethanol blend ratio for motorcycle engine using response surface method.

PubMed

Chen, Yu-Liang; Chen, Suming; Tsai, Jin-Ming; Tsai, Chao-Yin; Fang, Hsin-Hsiung; Yang, I-Chang; Liu, Sen-Yuan

2012-01-01

In view of energy shortage and air pollution, ethanol-gasoline blended fuel used for motorcycle engine was studied in this work. The emissions of carbon monoxide (CO), nitrogen oxides (NO(X)) and engine performance of a 125 cc four-stroke motorcycle engine with original carburetor using ethanol-gasoline fuels were investigated. The model of three-variable Box Behnken design (BBD) was used for experimental design, the ethanol blend ratios were prepared at 0, 10, 20 vol%; the speeds of motorcycle were selected as 30, 45, 60 km/h; and the throttle positions were set at 30, 60, 90 %. Both engine performance and air pollutant emissions were then analyzed by response surface method (RSM) to yield optimum operation parameters for tolerable pollutant emissions and maximum engine performance. The RSM optimization analysis indicated that the most suitable ethanol-gasoline blended ratio was found at the range of 3.92-4.12 vol% to yield a comparable fuel conversion efficiency, while considerable reductions of exhaust pollutant emissions of CO (-29 %) and NO(X) (-12 %) when compared to pure gasoline fuel. This study demonstrated low ethanol-gasoline blended fuels could be used in motorcycle carburetor engines without any modification to keep engine power while reducing exhaust pollutants.

Closed loop engine control for regulating NOx emissions, using a two-dimensional fuel-air curve

DOEpatents

Bourn, Gary D.; Smith, Jack A.; Gingrich, Jess W.

2007-01-30

An engine control strategy that ensures that NOx emissions from the engine will be maintained at an acceptable level. The control strategy is based on a two-dimensional fuel-air curve, in which air manifold pressure (AMP) is a function of fuel header pressure and engine speed. The control strategy provides for closed loop NOx adjustment to a base AMP value derived from the fuel-air curve.

Speciation and chemical evolution of nitrogen oxides in aircraft exhaust near airports.

PubMed

Wood, Ezra C; Herndon, Scott C; Timko, Michael T; Yelvington, Paul E; Miake-Lye, Richard C

2008-03-15

Measurements of nitrogen oxides from a variety of commercial aircraft engines as part of the JETS-APEX2 and APEX3 campaigns show that NOx (NOx [triple bond] NO + NO2) is emitted primarily in the form of NO2 at idle thrust and NO at high thrust. A chemical kinetics combustion model reproduces the observed NO2 and NOx trends with engine power and sheds light on the relevant chemical mechanisms. Experimental evidence is presented of rapid conversion of NO to NO2 in the exhaust plume from engines at low thrust. The rapid conversion and the high NO2/NOx emission ratios observed are unrelated to ozone chemistry. NO2 emissions from a CFM56-3B1 engine account for approximately 25% of the NOx emitted below 3000 feet (916 m) and 50% of NOx emitted below 500 feet (153 m) during a standard ICAO (International Civil Aviation Organization) landing-takeoff cycle. Nitrous acid (HONO) accounts for 0.5% to 7% of NOy emissions from aircraft exhaust depending on thrust and engine type. Implications for photochemistry near airports resulting from aircraft emissions are discussed.

Evaluation of fuel-borne sodium effects on a DOC-DPF-SCR heavy-duty engine emission control system: Simulation of full-useful life

DOE PAGES

Lance, Michael J.; Wereszczak, Andrew A; Toops, Todd J.; ...

2016-10-17

Here we report that for renewable fuels to displace petroleum, they must be compatible with emissions control devices. Pure biodiesel contains up to 5 ppm Na + K and 5 ppm Ca + Mg metals, which have the potential to degrade diesel emissions control systems. This study aims to address these concerns, identify deactivation mechanisms, and determine if a lower limit is needed. Accelerated aging of a production exhaust system was conducted on an engine test stand over 1001 h using 20% biodiesel blended into ultra-low sulfur diesel (B20) doped with 14 ppm Na. This Na level is equivalent tomore » exposure to Na at the uppermost expected B100 value in a B20 blend for the system full-useful life. During the study, NOx emissions exceeded the engine certification limit of 0.33 g/bhp-hr before the 435,000-mile requirement. Replacing aged diesel oxidation catalyst (DOC), diesel particulate filter (DPF), and selective catalytic reduction (SCR) devices with new degreened parts showed that each device contributed equally to the NOx increase. Following this systems-based evaluation, a detailed investigation of the individual components was completed. Na was determined to have minimal impact on DOC activity. For this system, it is estimated that B20-Na resulted in 50% more ash into the DPF. However, the Na did not diffuse into the cordierite DPF nor degrade its mechanical properties. The SCR degradation was found to be caused by a small amount of precious group metals (PGM) contamination that increased NH3 oxidation, and lowered NOx reduction. Therefore, we determined that the primary effect of Na in this study is through increased ash in the DPF rather than deactivation of the catalytic activity.« less

Evaluation of fuel-borne sodium effects on a DOC-DPF-SCR heavy-duty engine emission control system: Simulation of full-useful life

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lance, Michael J.; Wereszczak, Andrew A; Toops, Todd J.

Here we report that for renewable fuels to displace petroleum, they must be compatible with emissions control devices. Pure biodiesel contains up to 5 ppm Na + K and 5 ppm Ca + Mg metals, which have the potential to degrade diesel emissions control systems. This study aims to address these concerns, identify deactivation mechanisms, and determine if a lower limit is needed. Accelerated aging of a production exhaust system was conducted on an engine test stand over 1001 h using 20% biodiesel blended into ultra-low sulfur diesel (B20) doped with 14 ppm Na. This Na level is equivalent tomore » exposure to Na at the uppermost expected B100 value in a B20 blend for the system full-useful life. During the study, NOx emissions exceeded the engine certification limit of 0.33 g/bhp-hr before the 435,000-mile requirement. Replacing aged diesel oxidation catalyst (DOC), diesel particulate filter (DPF), and selective catalytic reduction (SCR) devices with new degreened parts showed that each device contributed equally to the NOx increase. Following this systems-based evaluation, a detailed investigation of the individual components was completed. Na was determined to have minimal impact on DOC activity. For this system, it is estimated that B20-Na resulted in 50% more ash into the DPF. However, the Na did not diffuse into the cordierite DPF nor degrade its mechanical properties. The SCR degradation was found to be caused by a small amount of precious group metals (PGM) contamination that increased NH3 oxidation, and lowered NOx reduction. Therefore, we determined that the primary effect of Na in this study is through increased ash in the DPF rather than deactivation of the catalytic activity.« less

Experimental study on the nitrogen dioxide and particulate matter emissions from diesel engine retrofitted with particulate oxidation catalyst.

PubMed

Feng, Xiangyu; Ge, Yunshan; Ma, Chaochen; Tan, Jianwei; Yu, Linxiao; Li, Jiaqiang; Wang, Xin

2014-02-15

A particulate oxidation catalyst (POC) was employed to perform experiments on the engine test bench to evaluate the effects on the nitrogen dioxide (NO2) and particulate matter (PM) emissions from diesel engine. The engine exhaust was sampled from both upstream and downstream of the POC. The results showed that the POC increased the ratios of NO2/NOx significantly in the middle and high loads, the ratio of NO2/nitrogen oxides (NOx) increased 4.5 times on average under all experiment modes with the POC. An engine exhaust particle sizer (EEPS) was used to study the particle number-weighted size distributions and the abnormal particle emissions with the POC. The results indicated that the average reduction rate of particle number (PN) was 61% in the operating range of the diesel engine. At the engine speed of 1,400 r/min, the reduction rates of PN tended to decrease with the larger particle size. In the long time run under the steady mode (520 Nm, 1,200 r/min), abnormal particle emissions after the POC happened seven times in the first hour, and the average PN concentration of these abnormal emission peaks was much higher than that in normal state. The particle emissions of peaks 1-5 equaled the particles emitted downstream of the POC in normal state for 1.9h in number concentration, and for 3.6h in mass concentration. The PN concentrations tended to increase over time in 5h under the steady engine mode and the increase of the PN in the size range of 6.04-14.3 nm was more evident. Copyright © 2013 Elsevier B.V. All rights reserved.

COST OF SELECTIVE CATALYTIC REDUCTION (SCR) APPLICATION FOR NOX CONTROL ON COAL-FIRED BOILERS

EPA Science Inventory

The report provides a methodology for estimating budgetary costs associated with retrofit applications of selective catalytic reduction (SCR) technology on coal-fired boilers. SCR is a postcombustion nitrogen oxides (NOx) control technology capable of providing NOx reductions >90...

Demonstration of Diesel Engine Air Emissions Reduction Technologies

DTIC Science & Technology

2008-12-01

16 Figure 5. Plots of Cheyenne Mountain Operating Cycle and Reference CBD Driving...Air Act CARB California Air Resources Board CBD Central Business District CCR California Code of Regulations CES Cummins Emissions Solutions CFR...matter ppb parts per billion ppm parts per million PuriNOx Proprietary Water / Diesel Emulsified Fuel RPF robust particulate filter THC total

COST OF SELECTIVE CATALYTIC REDUCTION (SCR) APPLICATION FOR NOX CONTROL ON COAL-FIRED BOILERS

EPA Science Inventory

The report provides a methodology for estimating budgetary costs associ-ated with retrofit applications of selec-tive catalytic reduction (SCR) technology on coal-fired boilers. SCR is a post-combustion nitrogen oxides (NOX) con-trol technology capable of providing NOX reductions...

A comparative evaluation on the emission characteristics of ceramic and metallic catalytic converter in internal combustion engine

NASA Astrophysics Data System (ADS)

Leman, A. M.; Jajuli, Afiqah; Rahman, Fakhrurrazi; Feriyanto, Dafit; Zakaria, Supaat

2017-09-01

Enforcement of a stricter regulation on exhaust emission by many countries has led to utilization of catalytic converter to reduce the harmful pollutant emission. Ceramic and metallic catalytic converters are the most common type of catalytic converter used. The purpose of this study is to evaluate the performance of the ceramic and metallic catalytic converter on its conversion efficiency using experimental measurement. Both catalysts were placed on a modified exhaust system equipped with a Mitshubishi 4G93 single cylinder petrol engine that was tested on an eddy current dynamometer under steady state conditions for several engine speeds. The experimental results show that the metallic catalytic converter reduced a higher percentage of CO up to 98.6% reduction emissions while ceramic catalytic converter had a better reduction efficiency of HC up to 85.4% and 87.2% reduction of NOx.

Off-Highway Heavy Vehicle Diesel Efficiency Improvement and Emissions Reduction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jennifer Rumsey

2005-12-31

Cummins Inc. is a world leader in the development and production of diesel engines for on-highway vehicles, off-highway industrial machines, and power generation units. Cummins Inc. diesel products cover a 50-3000 HP range. The power range for this project includes 174-750 HP to achieve EPA's Tier 3 emission levels of 4.0 NOx+NMHC gm/kW-hr and 0.2 PM gm/kWhr and Tier 4 Interim emission levels of 2.0 gm/kW-hr NOx and 0.02 gm/kW-hr PM. Cummins' anticipated product offerings for Tier 4 in this range include the following: QSB6.7, QSC8.3, QSL9, QSM11, QSX15, QSK19. (For reference, numerical values indicate engine displacement in liters, themore » letter designation ns indicate the product model). A summary of the EPA's mobile off-highway emissions requirements is given in Figure 1.« less

Lagrangian Hotspots of In-Use NOX Emissions from Transit Buses.

PubMed

Kotz, Andrew J; Kittelson, David B; Northrop, William F

2016-06-07

In-use, spatiotemporal NOX emissions were measured from a conventional powertrain transit bus and a series electric hybrid bus over gradients of route kinetic intensity and ambient temperature. This paper introduces a new method for identifying NOX emissions hotspots along a bus route using high fidelity Lagrangian vehicle data to explore spatial interactions that may influence emissions production. Our study shows that the studied transit buses emit higher than regulated emissions because on-route operation does not accurately represent the range of engine operation tested according to regulatory standards. Using the Lagrangian hotspot detection, we demonstrate that NOX hotspots occurred at bus stops, during cold starts, on inclines, and for accelerations. On the selected routes, bus stops resulted in 3.3 times the route averaged emissions factor in grams/km without significant dependence on bus type or climate. The buses also emitted 2.3 times the route averaged NOX emissions factor at the beginning of each route due to cold selective catalytic reduction aftertreatment temperature. The Lagrangian hotspot detection technique demonstrated here could be employed in future connected vehicles empowered by advances in computational power, data storage capability, and improved sensor technology to optimize emissions as a function of spatial location.

NASA N3-X with Turboelectric Distributed Propulsion

NASA Technical Reports Server (NTRS)

Felder, James L.

2014-01-01

Presentation summarizing the phase I study of the NASA N3-X turboelectric distributed propulsion power aircraft to the IMechE Disruptive Green Propulsion Technologies conference in London, UK November 16th and 17th, 2014. This presentation contains the results of a NASA internal study funded by the NASA Fixed Wing program to look at the application of turboelectric distributed propulsion to a long-range 300 seat aircraft. The reference aircraft is the Boeing 777-200LR. The N3-X reduced energy consumption by 70 compared to the 777-200LR, LTO NOx by 85 compared to the CAEP 6 limits, and noise by 32-64 EPNdB depending on engine placement compared to the stage 4 noise standards. This exceeded the N+3 metrics of reducing energy by 60, LTO NOx by 80, and noise by 52 EPNdB. Cruise NOx was not estimated, but likely meet the 80 reduction goal as well.

Near-field commercial aircraft contribution to nitrogen oxides by engine, aircraft type, and airline by individual plume sampling.

PubMed

Carslaw, David C; Ropkins, Karl; Laxen, Duncan; Moorcroft, Stephen; Marner, Ben; Williams, Martin L

2008-03-15

Nitrogen oxides (NOx) concentrations were measured in individual plumes from aircraft departing on the northern runway at Heathrow Airport in west London. Over a period of four weeks 5618 individual plumes were sampled by a chemiluminescence monitor located 180 m from the runway. Results were processed and matched with detailed aircraft movement and aircraft engine data using chromatographic techniques. Peak concentrations associated with 29 commonly used engines were calculated and found to have a good relationship with N0x emissions taken from the International Civil Aviation Organization (ICAO) databank. However, it is found that engines with higher reported NOx emissions result in proportionately lower NOx concentrations than engines with lower emissions. We show that it is likely that aircraft operational factors such as takeoff weight and aircraftthrust setting have a measurable and important effect on concentrations of N0x. For example, NOx concentrations can differ by up to 41% for aircraft using the same airframe and engine type, while those due to the same engine type in different airframes can differ by 28%. These differences are as great as, if not greater than, the reported differences in NOx emissions between different engine manufacturers for engines used on the same airframe.

Introducing the VRT gas turbine combustor

NASA Technical Reports Server (NTRS)

Melconian, Jerry O.; Mostafa, Abdu A.; Nguyen, Hung Lee

1990-01-01

An innovative annular combustor configuration is being developed for aircraft and other gas turbine engines. This design has the potential of permitting higher turbine inlet temperatures by reducing the pattern factor and providing a major reduction in NO(x) emission. The design concept is based on a Variable Residence Time (VRT) technique which allows large fuel particles adequate time to completely burn in the circumferentially mixed primary zone. High durability of the combustor is achieved by dual function use of the incoming air. The feasibility of the concept was demonstrated by water analogue tests and 3-D computer modeling. The computer model predicted a 50 percent reduction in pattern factor when compared to a state of the art conventional combustor. The VRT combustor uses only half the number of fuel nozzles of the conventional configuration. The results of the chemical kinetics model require further investigation, as the NO(x) predictions did not correlate with the available experimental and analytical data base.

Prediction of the production of nitrogen oxide (NOx) in turbojet engines

NASA Astrophysics Data System (ADS)

Tsague, Louis; Tsogo, Joseph; Tatietse, Thomas Tamo

Gaseous nitrogen oxides (NO+NO2=NOx) are known as atmospheric trace constituent. These gases remain a big concern despite the advances in low NOx emission technology because they play a critical role in regulating the oxidization capacity of the atmosphere according to Crutzen [1995. My life with O 3, NO x and other YZO x S; Nobel Lecture; Chemistry 1995; pp 195; December 8, 1995] . Aircraft emissions of nitrogen oxides ( NOx) are regulated by the International Civil Aviation Organization. The prediction of NOx emission in turbojet engines by combining combustion operational data produced information showing correlation between the analytical and empirical results. There is close similarity between the calculated emission index and experimental data. The correlation shows improved accuracy when the 2124 experimental data from 11 gas turbine engines are evaluated than a previous semi empirical correlation approach proposed by Pearce et al. [1993. The prediction of thermal NOx in gas turbine exhausts. Eleventh International Symposium on Air Breathing Engines, Tokyo, 1993, pp. 6-9]. The new method we propose predict the production of NOx with far more improved accuracy than previous methods. Since a turbojet engine works in an atmosphere where temperature, pressure and humidity change frequently, a correction factor is developed with standard atmospheric laws and some correlations taken from scientific literature [Swartwelder, M., 2000. Aerospace engineering 410 Term Project performance analysis, November 17, 2000, pp. 2-5; Reed, J.A. Java Gas Turbine Simulator Documentation. pp. 4-5]. The new correction factor is validated with experimental observations from 19 turbojet engines cruising at altitudes of 9 and 13 km given in the ICAO repertory [Middleton, D., 1992. Appendix K (FAA/SETA). Section 1: Boeing Method Two Indices, 1992, pp. 2-3]. This correction factor will enable the prediction of cruise NOx emissions of turbojet engines at cruising speeds. The ICAO database [Goehlich, R.A., 2000. Investigation into the applicability of pollutant emission models for computer aided preliminary aircraft design, Book number 175654, 4.2.2000, pp. 57-79] can now be completed using the approach we propose to complete the whole mission flight NOx emissions.

Vanadium and tungsten release from V-based selective catalytic reduction diesel aftertreatment

NASA Astrophysics Data System (ADS)

Liu, Z. Gerald; Ottinger, Nathan A.; Cremeens, Christopher M.

2015-03-01

Vanadium-based selective catalytic reduction (V-SCR) catalysts are currently used for the reduction of nitrogen oxides (NOx) in worldwide diesel applications including Euro IV, V, and VI as well as U.S. nonroad Tier 4 Final. Although V-SCR catalysts are attractive because of their high NOx conversion, low cost, resistance to sulfur poisoning, and ability to reduce hydrocarbon emissions, there is concern that V-SCR washcoat material (e.g., vanadium and tungsten) and its derivatives may be released into the atmosphere, potentially harming human health and the environment. In this study, vanadium and tungsten release measurements are made with both a reactor- and engine-based approach in order to determine the potential release of these metals from diesel exhaust aftertreatment systems that contain a V-SCR catalyst. Results for a commercially available V-SCR reveal that both V and W release begin at 500 °C, and both reactor- and engine-based methods are capable of measuring qualitatively similar release. Emissions with the engine-based method are higher at all temperatures evaluated, likely due to this method's ability to capture particle-phase and vapor-phase emissions which become particle-bound after their evolution from the catalyst surface. Certification relevant data (NRTC and NRSC) from a nonroad engine is used to understand probable emissions from V-SCR aftertreatment architectures. Finally, results from a V-SCR catalyst formulated for improved thermal durability illustrate that it is possible to increase the maximum temperature for V-SCR catalysts. This comprehensive understanding of the temperature dependence of vanadium and tungsten volatility can be used to further analyze the full impact of diesel aftertreatment on exhaust emissions and their impact on human health and environmental toxicity.

Quantification of the enhanced effectiveness of NOx control from simultaneous reductions of VOC and NH3 for reducing air pollution in the Beijing-Tianjin-Hebei region, China

NASA Astrophysics Data System (ADS)

Xing, Jia; Ding, Dian; Wang, Shuxiao; Zhao, Bin; Jang, Carey; Wu, Wenjing; Zhang, Fenfen; Zhu, Yun; Hao, Jiming

2018-06-01

As one common precursor for both PM2.5 and O3 pollution, NOx gains great attention because its controls can be beneficial for reducing both PM2.5 and O3. However, the effectiveness of NOx controls for reducing PM2.5 and O3 are largely influenced by the ambient levels of NH3 and VOC, exhibiting strong nonlinearities characterized as NH3-limited/NH3-poor and NOx-/VOC-limited conditions, respectively. Quantification of such nonlinearities is a prerequisite for making suitable policy decisions but limitations of existing methods were recognized. In this study, a new method was developed by fitting multiple simulations of a chemical transport model (i.e., Community Multiscale Air Quality Modeling System, CMAQ) with a set of polynomial functions (denoted as pf-RSM) to quantify responses of ambient PM2.5 and O3 concentrations to changes in precursor emissions. The accuracy of the pf-RSM is carefully examined to meet the criteria of a mean normalized error within 2 % and a maximal normalized error within 10 % by using 40 training samples with marginal processing. An advantage of the pf-RSM method is that the nonlinearity in PM2.5 and O3 responses to precursor emission changes can be characterized by quantitative indicators, including (1) a peak ratio (denoted as PR) representing VOC-limited or NOx-limited conditions, (2) a suggested ratio of VOC reduction to NOx reduction to avoid increasing O3 under VOC-limited conditions, (3) a flex ratio (denoted as FR) representing NH3-poor or NH3-rich conditions, and (4) enhanced benefits in PM2.5 reductions from simultaneous reduction of NH3 with the same reduction rate of NOx. A case study in the Beijing-Tianjin-Hebei region suggested that most urban areas present strong VOC-limited conditions with a PR from 0.4 to 0.8 in July, implying that the NOx emission reduction rate needs to be greater than 20-60 % to pass the transition from VOC-limited to NOx-limited conditions. A simultaneous VOC control (the ratio of VOC reduction to NOx reduction is about 0.5-1.2) can avoid increasing O3 during the transition. For PM2.5, most urban areas present strong NH3-rich conditions with a PR from 0.75 to 0.95, implying that NH3 is sufficiently abundant to neutralize extra nitric acid produced by an additional 5-35 % of NOx emissions. Enhanced benefits in PM2.5 reductions from simultaneous reduction of NH3 were estimated to be 0.04-0.15 µg m-3 PM2.5 per 1 % reduction of NH3 along with NOx, with greater benefits in July when the NH3-rich conditions are not as strong as in January. Thus, the newly developed pf-RSM model has successfully quantified the enhanced effectiveness of NOx control, and simultaneous reduction of VOC and NH3 with NOx can assure the control effectiveness of PM2.5 and O3.

75 FR 6305 - Approval and Promulgation of Air Quality Implementation Plans; West Virginia; Removal of NOX

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-09

... the electric generating units (EGUs) that are subject to the NO X SIP Call but does not apply to the... to recodify the provisions for its non-trading non-EGUs (internal combustion engines and cement kilns... and Reduction of Nitrogen Oxides from Non-Electric Generating Units As a Means to Mitigate Transport...

Oxide_Oxide Ceramic Matrix Composite (CMC) Exhaust Mixer Development in the NASA Environmentally Responsible Aviation (ERA) Project

NASA Technical Reports Server (NTRS)

Kiser, J. Douglas; Bansal, Narottam P.; Szelagowski, James; Sokhey, Jagdish; Heffernan, Tab; Clegg, Joseph; Pierluissi, Anthony; Riedell, Jim; Wyen, Travis; Atmur, Steven;

Chemiluminescence analyzer of NOx as a high-throughput screening tool in selective catalytic reduction of NO

PubMed Central

Oh, Kwang Seok; Woo, Seong Ihl

2011-01-01

A chemiluminescence-based analyzer of NOx gas species has been applied for high-throughput screening of a library of catalytic materials. The applicability of the commercial NOx analyzer as a rapid screening tool was evaluated using selective catalytic reduction of NO gas. A library of 60 binary alloys composed of Pt and Co, Zr, La, Ce, Fe or W on Al2O3 substrate was tested for the efficiency of NOx removal using a home-built 64-channel parallel and sequential tubular reactor. The NOx concentrations measured by the NOx analyzer agreed well with the results obtained using micro gas chromatography for a reference catalyst consisting of 1 wt% Pt on γ-Al2O3. Most alloys showed high efficiency at 275 °C, which is typical of Pt-based catalysts for selective catalytic reduction of NO. The screening with NOx analyzer allowed to select Pt-Ce(X) (X=1–3) and Pt–Fe(2) as the optimal catalysts for NOx removal: 73% NOx conversion was achieved with the Pt–Fe(2) alloy, which was much better than the results for the reference catalyst and the other library alloys. This study demonstrates a sequential high-throughput method of practical evaluation of catalysts for the selective reduction of NO. PMID:27877438

40 CFR 1042.104 - Exhaust emission standards for Category 3 engines.

Code of Federal Regulations, 2010 CFR

2010-07-01

... for other testing. (2) NOX standards apply based on the engine's model year and maximum in-use engine... Engines (g/kW-hr) Emission standards Model year Maximum in-use engine speed Less than130 RPM 130-2000RPM a... Tier 1 NOX standards apply as specified in 40 CFR part 94 for engines originally manufactured in model...

40 CFR 1042.104 - Exhaust emission standards for Category 3 engines.

Code of Federal Regulations, 2011 CFR

2011-07-01

... for other testing. (2) NOX standards apply based on the engine's model year and maximum in-use engine... Engines (g/kW-hr) Emission standards Model year Maximum in-use engine speed Less than130 RPM 130-2000RPM a... Tier 1 NOX standards apply as specified in 40 CFR part 94 for engines originally manufactured in model...

40 CFR 1042.104 - Exhaust emission standards for Category 3 engines.

Code of Federal Regulations, 2012 CFR

2012-07-01

... for other testing. (2) NOX standards apply based on the engine's model year and maximum in-use engine... Engines (g/kW-hr) Emission standards Model year Maximum in-use engine speed Less than130 RPM 130-2000RPM a... Tier 1 NOX standards apply as specified in 40 CFR part 94 for engines originally manufactured in model...

A study on the indirect urea dosing method in the Selective Catalytic Reduction system

NASA Astrophysics Data System (ADS)

Brzeżański, M.; Sala, R.

2016-09-01

This article presents the results of studies on concept solution of dosing urea in a gas phase in a selective catalytic reduction system. The idea of the concept was to heat-up and evaporate the water urea solution before introducing it into the exhaust gas stream. The aim was to enhance the processes of urea converting into ammonia, what is the target reductant for nitrogen oxides treatment. The study was conducted on a medium-duty Euro 5 diesel engine with exhaust line consisting of DOC catalyst, DPF filter and an SCR system with a changeable setup allowing to dose the urea in liquid phase (regular solution) and to dose it in a gas phase (concept solution). The main criteria was to assess the effect of physical state of urea dosed on the NOx conversion ratio in the SCR catalyst. In order to compare both urea dosing methods a special test procedure was developed which consisted of six test steps covering a wide temperature range of exhaust gas generated at steady state engine operation condition. Tests were conducted for different urea dosing quantities defined by the a equivalence ratio. Based on the obtained results, a remarkable improvement in NOx reduction was found for gas urea application in comparison to the standard liquid urea dosing. Measured results indicate a high potential to increase an efficiency of the SCR catalyst by using a gas phase urea and provide the basis for further scientific research on this type of concept.

40 CFR 90.104 - Compliance with emission standards.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Volume Engine Families Engine class Two-stroke engines 1 HC+NOX CO Four-stroke engines HC+NOX CO Engines...). Class IV 1.1 1.1 1.5 1.1 Class V 1.1 1.1 1.5 1.1 1 Two-stroke technologies to which these assigned deterioration factors apply include conventional two-strokes, compression wave designs, and stratified...

40 CFR 90.104 - Compliance with emission standards.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Volume Engine Families Engine class Two-stroke engines 1 HC+NOX CO Four-stroke engines HC+NOX CO Engines...). Class IV 1.1 1.1 1.5 1.1 Class V 1.1 1.1 1.5 1.1 1 Two-stroke technologies to which these assigned deterioration factors apply include conventional two-strokes, compression wave designs, and stratified...

40 CFR 90.104 - Compliance with emission standards.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Volume Engine Families Engine class Two-stroke engines 1 HC+NOX CO Four-stroke engines HC+NOX CO Engines...). Class IV 1.1 1.1 1.5 1.1 Class V 1.1 1.1 1.5 1.1 1 Two-stroke technologies to which these assigned deterioration factors apply include conventional two-strokes, compression wave designs, and stratified...

40 CFR 90.104 - Compliance with emission standards.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Volume Engine Families Engine class Two-stroke engines 1 HC+NOX CO Four-stroke engines HC+NOX CO Engines...). Class IV 1.1 1.1 1.5 1.1 Class V 1.1 1.1 1.5 1.1 1 Two-stroke technologies to which these assigned deterioration factors apply include conventional two-strokes, compression wave designs, and stratified...

40 CFR 90.104 - Compliance with emission standards.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Volume Engine Families Engine class Two-stroke engines 1 HC+NOX CO Four-stroke engines HC+NOX CO Engines...). Class IV 1.1 1.1 1.5 1.1 Class V 1.1 1.1 1.5 1.1 1 Two-stroke technologies to which these assigned deterioration factors apply include conventional two-strokes, compression wave designs, and stratified...

Investigation on the gaseous and particulate emissions of a compression ignition engine fueled with diesel-dimethyl carbonate blends.

PubMed

Cheung, C S; Zhu, Ruijun; Huang, Zuohua

2011-01-01

The effect of dimethyl carbonate (DMC) on the gaseous and particulate emissions of a diesel engine was investigated using Euro V diesel fuel blended with different proportions of DMC. Combustion analysis shows that, with the blended fuel, the ignition delay and the heat release rate in the premixed combustion phase increase, while the total combustion duration and the fuel consumed in the diffusion combustion phase decrease. Compared with diesel fuel, with an increase of DMC in the blended fuel, the brake thermal efficiency is slightly improved but the brake specific fuel consumption increases. On the emission side, CO increases significantly at low engine load but decreases at high engine load while HC decreases slightly. NO(x) reduces slightly but the reduction is not statistically significant, while NO(2) increases slightly. Particulate mass and number concentrations decrease upon using the blended fuel while the geometric mean diameter of the particles shifts towards smaller size. Overall speaking, diesel-DMC blends lead to significant improvement in particulate emissions while the impact on CO, HC and NO(x) emissions is small. Copyright © 2010 Elsevier B.V. All rights reserved.

Promoted decomposition of NOx in automotive diesel-like exhausts by electro-catalytic honeycombs.

PubMed

Huang, Ta-Jen; Chiang, De-Yi; Shih, Chi; Lee, Cheng-Chin; Mao, Chih-Wei; Wang, Bo-Chung

2015-03-17

NO and NO2 (collectively called NOx) are major air pollutants in automotive emissions. More effective and easier treatments of NOx than those achieved by the present methods can offer better protection of human health and higher fuel efficiency that can reduce greenhouse gas emissions. However, currently commercialized technologies for automotive NOx emission control cannot effectively treat diesel-like exhausts with high NOx concentrations. Thus, exhaust gas recirculation (EGR) has been used extensively, which reduces fuel efficiency and increases particulate emission considerably. Our results show that the electro-catalytic honeycomb (ECH) promotes the decomposition of NOx to nitrogen and oxygen, without consuming reagents or other resources. NOx can be converted to nitrogen and oxygen almost completely. The ECHs are shown to effectively remove NOx from gasoline-fueled diesel-like exhausts. A very high NO concentration is preferred in the engine exhaust, especially during engine cold-start. Promoted NOx decomposition (PND) technology for real-world automotive applications is established in this study by using the ECH. With PND, EGR is no longer needed. Diesel-like engines can therefore achieve superior fuel efficiency, and all major automotive pollutants can be easily treated due to high concentration of oxygen in the diesel-like exhausts, leading to zero pollution.

Experimental investigation on the availability, performance, combustion and emission distinctiveness of bael oil/ diesel/ diethyl ether blends powered in a variable compression ratio diesel engine

NASA Astrophysics Data System (ADS)

Krishnamoorthi, M.; Malayalamurthi, R.

2018-02-01

The present work aims at experimental investigation on the combined effect of injection timing (IT) and injection pressure (IP) on the performance and emissions characteristics, and exergy analysis of a compression-ignition (CI) engine powered with bael oil blends. The tests were conducted using ternary blends of bael oil, diethyl ether (DEE) and neat diesel (D) at various engine loads at a constant engine speed (1500 rpm). With B2 (60%D + 30%bael oil+10%DEE) fuel, the brake thermal efficiency (BTE) of the engine is augmented by 3.5%, reduction of 4.7% of oxides of nitrogen (NOx) emission has been observed at 100% engine load with 250 bar IP. B2 fuel exhibits 7% lower scale of HC emissions compared to that of diesel fuel at 100% engine load in 23 °bTDC IT. The increment in both cooling water and exhaust gas availabilities lead to increasing exergy efficiency with increasing load. The exergy efficiency of about 62.17% has been recorded by B2 fuel at an injection pressure of 230 IP bar with 100% load. On the whole, B2 fuel displays the best performance and combustion characteristics. It also exhibits better characteristics of emissions level in terms of lower HC, smoke opacity and NOx.

Effects of Particle Filters and Selective Catalytic Reduction on In-Use Heavy-Duty Diesel Truck Emissions

NASA Astrophysics Data System (ADS)

Preble, C.; Cados, T.; Harley, R.; Kirchstetter, T.

2016-12-01

Heavy-duty diesel trucks (HDDT) are a major source of nitrogen oxides (NOx) and black carbon (BC) in urban environments, contributing to persistent ozone and particulate matter air quality problems. Diesel particle filters (DPFs) and selective catalytic reduction (SCR) systems that target PM and NOx emissions, respectively, have recently become standard equipment on new HDDT. DPFs can also be installed on older engines as a retrofit device. Previous work has shown that DPF and SCR systems can reduce NOx and BC emissions by up to 70% and 90%, respectively, compared to modern trucks without these after-treatment controls (Preble et al., ES&T 2015). DPFs can have the undesirable side-effect of increasing ultrafine particle (UFP) and nitrogen dioxide (NO2) emissions. While SCR systems can partially mitigate DPF-related NO2 increases, these systems can emit nitrous oxide (N2O), a potent greenhouse gas. We report new results from a study of HDDT emissions conducted in fall 2015 at the Port of Oakland and Caldecott Tunnel in California's San Francisco Bay Area. We report pollutant emission factors (g kg-1) for emitted NOx, NO2, BC, PM2.5, UFP, and N2O on a truck-by-truck basis. Using a roadside license plate recognition system, we categorize each truck by its engine model year and installed after-treatment controls. From this, we develop emissions profiles for trucks with and without DPF and SCR. We evaluate the effectiveness of these devices as a function of their age to determine whether degradation is an issue. We also compare the emission profiles of trucks traveling at low speeds along a level, arterial road en route to the port and at high speeds up a 4% grade highway approaching the tunnel. Given the climate impacts of BC and N2O, we also examine the global warming potential of emissions from trucks with and without DPF and SCR.

High-Potential Electrocatalytic O2 Reduction with Nitroxyl/NOx Mediators: Implications for Fuel Cells and Aerobic Oxidation Catalysis

PubMed Central

2015-01-01

Efficient reduction of O2 to water is a central challenge in energy conversion and many aerobic oxidation reactions. Here, we show that the electrochemical oxygen reduction reaction (ORR) can be achieved at high potentials by using soluble organic nitroxyl and nitrogen oxide (NOx) mediators. When used alone, neither organic nitroxyls, such as 2,2,6,6-tetramethyl-1-piperidinyl-N-oxyl (TEMPO), nor NOx species, such as sodium nitrite, are effective ORR mediators. The combination of nitroxyl/NOx species, however, mediates sustained O2 reduction with overpotentials as low as 300 mV in acetonitrile containing trifluoroacetic acid. Mechanistic analysis of the coupled redox reactions supports a process in which the nitrogen oxide catalyst drives aerobic oxidation of a nitroxyl mediator to an oxoammonium species, which then is reduced back to the nitroxyl at the cathode. The electrolysis potential is dictated by the oxoammonium/nitroxyl reduction potential. The overpotentials accessible with this ORR system are significantly lower than widely studied molecular metal-macrocycle ORR catalysts and benefit from the mechanism-based specificity for four-electron reduction of oxygen to water mediated by NOx species, together with kinetically efficient reduction of oxidized NOx species by TEMPO and other organic nitroxyls. PMID:27162977

Physical and Chemical Processes in Flames

DTIC Science & Technology

2010-02-15

7. "An efficient reduced mechanism for methane oxidation with NOx chemistry ," by T. F. Lu and C. K. Law, Paper No. C17, Fifth US Combustion Meeting... Mechanical and Aerospace Engineering Princeton University Princeton, NJ 08544 9. SPONSORING I MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR...TERMS Laminar flame speeds; ignition temperatures; extinction limits; mechanism reduction; skeletal mechanism ; CO/H2 oxidation; ethy lene oxidation

40 CFR 94.306 - Certification.

Code of Federal Regulations, 2013 CFR

2013-07-01

... declarations are required for each pollutant (THC+NOX and PM). (2) Declare FELs for each engine family... model year. Manufacturers that have certified engine families with credit balances for THC+NOX and/or PM...

40 CFR 94.306 - Certification.

Code of Federal Regulations, 2011 CFR

2011-07-01

... declarations are required for each pollutant (THC+NOX and PM). (2) Declare FELs for each engine family... model year. Manufacturers that have certified engine families with credit balances for THC+NOX and/or PM...

40 CFR 94.306 - Certification.

Code of Federal Regulations, 2012 CFR

2012-07-01

... declarations are required for each pollutant (THC+NOX and PM). (2) Declare FELs for each engine family... model year. Manufacturers that have certified engine families with credit balances for THC+NOX and/or PM...

40 CFR 94.306 - Certification.

Code of Federal Regulations, 2014 CFR

2014-07-01

... declarations are required for each pollutant (THC+NOX and PM). (2) Declare FELs for each engine family... model year. Manufacturers that have certified engine families with credit balances for THC+NOX and/or PM...

40 CFR 94.306 - Certification.

Code of Federal Regulations, 2010 CFR

2010-07-01

... declarations are required for each pollutant (THC+NOX and PM). (2) Declare FELs for each engine family... model year. Manufacturers that have certified engine families with credit balances for THC+NOX and/or PM...

Combustion Chemistry of Biodiesel for the Use in Urban Transport Buses: Experiment and Modeling

NASA Astrophysics Data System (ADS)

Omidvarborna, Hamid

Biofuels, such as biodiesel, offer benefits as a possible alternative to conventional fuels due to their fuel source sustainability and their reduced environmental impact. Before they can be used, it is essential to understand their combustion chemistry and emission characterizations due to a number of issues associated with them (e.g., high emission of nitrogen oxides (NOx), lower heating value than diesel, etc.). During this study, emission characterizations of different biodiesel blends (B0, B20, B50, and B100) were measured on three different feedstocks (soybean methyl ester (SME), tallow oil (TO), and waste cooking oil (WCO)) with various characteristics, while an ultra-low sulfur diesel (ULSD) was used as base fuel at low-temperature combustion (LTC). A laboratory combustion chamber was used to analyze soot formation, NOx emissions, while real engine emissions were measured for further investigation on PM and NOx emissions. For further study, carbon emissions (CO, CO 2, and CH4) were also measured to understand their relations with feedstocks' type. The emissions were correlated with fuel's characteristics, especially unsaturation degree (number of double bonds in methyl esters) and chain length (oxygen-to-carbon ratio). The experimental results obtained from laboratory experiments were confirmed by field experiments (real engines) collected from Toledo area regional transit authority (TARTA) buses. Combustion analysis results showed that the neat biodiesel fuels had longer ignition delays and lower ignition temperatures compared to ULSD at the tested condition. The results showed that biodiesel containing more unsaturated fatty acids emitted higher levels of NOx compared to biodiesel with more saturated fatty acids. A paired t-test on fuels showed that neat biodiesel fuels had significant reduction in the formation of NOx compared with ULSD. In another part of this study, biodiesel fuel with a high degree of unsaturation and high portion of long chains of methyl esters (SME) produced more CO and less CO2 emissions than those with low degrees of unsaturation and short chain lengths (WCO and TO, respectively). In addition, biodiesel fuels with long and unsaturated chains released more CH4 than the ones with shorter and less unsaturated chains. Experimental results on soot particles showed a significant reduction in soot emissions when using biodiesel compared to ULSD. For neat biodiesel, no soot particles were observed from the combustion regardless of their feedstock origins. The overall morphology of soot particles showed that the average diameter of ULSD soot particles was greater than the average soot particle from biodiesel blends. Eight elements were detected as the marker metals in biodiesel soot particles. The conclusion suggests that selected characterization methods are valuable for studying the structure and distribution of particulates. Experiments on both PM and NOx emissions were conducted on real engines in parallel with laboratory study. Field experiments using TARTA buses were performed on buses equipped with/without post-treatment technologies. The performance of the bus that ran on blended biodiesel was found to be very similar to ULSD. As a part of this study, the toxic nature of engine exhausts under different idling conditions was studied. The results of the PM emission analysis showed that the PM mean value of emission is dependent on the engine operation conditions and fuel type. Besides, different idling modes were investigated with respect to organic carbon (OC), elemental carbon (EC), and elemental analysis of the PMs collected from public transit buses in Toledo, Ohio. In the modeling portion of this work, a simplified model was developed by using artificial neural network (ANN) to predict NOx emissions from TARTA buses via engine parameters. ANN results showed that the developed ANN model was capable of predicting the NOx emissions of the tested engines with excellent correlation coefficients, while root mean square errors (RMSEs) were in acceptable ranges. The ANN study confirmed that ANN can provide an accurate and simple approach in the analysis of complex and multivariate problems, especially for idle engine NOx emissions. Finally, in the last part of the modeling study, a biodiesel surrogate has been proposed and main pathways have been derived to present a simple model for NOx formation in biodiesel combustion via stochastic simulation algorithm (SSA). The main reaction pathways are obtained by simplifying the previously derived skeletal mechanisms, including saturated methyl decenoate (MD), unsaturated methyl 5-decanoate (MD5D), and n-decane (ND). ND is added to match the energy content and the C/H/O ratio of actual biodiesel fuel. The predicted results are in good agreement with a limited number of experimental data at LTC conditions for three different biodiesel fuels consisting of various ratios of unsaturated and saturated methyl esters. The SSA model shows the potential to predict NOx emission concentrations, when the peak combustion temperature increases through the addition of ULSD to biodiesel. The SSA method demonstrates the possibility of reducing the computational complexity in biodiesel emissions modeling. Based on these findings, it can be concluded that both alternative renewable fuels (biodiesel blends) as well as the LTC condition are suitable choices for existing diesel engines to improve the sustainability of fuel and to reduce environmental emissions.

NOX REMOVAL WITH COMBINED SELECTIVE CATALYTIC REDUCTION AND SELECTIVE NONCATALYTIC REDUCTION: PILOT- SCALE TEST RESULTS

EPA Science Inventory

Pilot-scale tests were conducted to develop a combined nitrogen oxide (NOx) reduction technology using both selective catalytic reduction (SCR) and selective noncatalytic reduction (SNCR). A commercially available vanadium-and titatnium-based composite honeycomb catalyst and enh...

40 CFR Table 1 to Subpart Jjjj of... - NOX, CO, and VOC Emission Standards for Stationary Non-Emergency SI Engines ≥100 HP (Except...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 6 2010-07-01 2010-07-01 false NOX, CO, and VOC Emission Standards for Stationary Non-Emergency SI Engines â¥100 HP (Except Gasoline and Rich Burn LPG), Stationary SI Landfill... Landfill/Digester Gas Engines, and Stationary Emergency Engines >25 HP Engine type and fuel Maximum engine...

Laboratory evaluation of a reactive baffle approach to NOx control. Final technical report, February-April 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nelson, S.G.; Van Stone, D.A.; Little, R.C.

1993-09-01

Vermiculite, vermiculite coated with magnesia, and activated carbon sorbents have successfully removed NOx (and carbon monoxide and particles) from combustion exhausts in a subscale drone jet engine test cell (JETC), but back pressure so generated elevated the temperature of the JETC and of the engine. The objective of this effort was to explore the feasibility of locating the sorbents in the face of the duct or of baffles parallel to the direction of flow within the ducts. Jet engine test cells (JETCs) are stationary sources of oxides of nitrogen (NOx), soot, and unburned or partially oxidized carbon compounds that formmore » as byproducts of imperfect combustion. Regulation of NOx emissions is being considered for implementation under the Clean Air Act Amendments of 1990. Several principles have been examined as candidate methods to control NOx emissions from JETCs.« less

Pollution reduction technology program small jet aircraft engines, phase 3

NASA Technical Reports Server (NTRS)

Bruce, T. W.; Davis, F. G.; Kuhn, T. E.; Mongia, H. C.

1981-01-01

A series of Model TFE731-2 engine tests were conducted with the Concept 2 variable geometry airblast fuel injector combustion system installed. The engine was tested to: (1) establish the emission levels over the selected points which comprise the Environmental Protection Agency Landing-Takeoff Cycle; (2) determine engine performance with the combustion system; and (3) evaulate the engine acceleration/deceleration characteristics. The hydrocarbon (HC), carbon monoxide (CO), and smoke goals were met. Oxides of nitrogen (NOx) were above the goal for the same configuration that met the other pollutant goals. The engine and combustor performance, as well as acceleration/deceleration characteristics, were acceptable. The Concept 3 staged combustor system was refined from earlier phase development and subjected to further rig refinement testing. The concept met all of the emissions goals.

REDUCING DIESEL NOX AND SOOT EMISSIONS VIA PARTICLE-FREE EXHAUST GAS RECIRCULATION - PHASE I

EPA Science Inventory

Diesel engines play an important role in the United States economy for power generation and transportation. However, NOx and soot emissions from both stationary and mobile diesel engines are a major contributor to air pollution. Many engine modifications and exhaust-after-t...

Comparison of NOx emissions from China III and China IV in-use diesel trucks based on on-road measurements

NASA Astrophysics Data System (ADS)

Yao, Zhiliang; Wu, Bobo; Wu, Yunong; Cao, Xinyue; Jiang, Xi

2015-12-01

To mitigate NOx and other emissions from diesel vehicles, China I, China II, China III and China IV emissions standards for new vehicles have been implemented nationwide. However, recent on-road measurements using a portable emission measurement system (PEMS) have revealed no significant reductions in the NOx emissions factors of diesel trucks due to the change from China II emissions standards to the more stringent China III standards. Thus, it is important to understand the effect of the China IV emissions standard on NOx emissions. In this study, nine China III and nine China IV diesel trucks of three sizes (light-duty diesel trucks (LDDTs), medium-duty diesel trucks (MDDTs) and heavy-duty diesel trucks (HDDTs)) were tested on real roads in Beijing using a PEMS. Compared to the tested China III diesel trucks, the China IV diesel trucks showed significant reductions of the average NOx emissions factors in terms of both distance travelled and fuel consumption. However, the driving conditions had an important impact on the reduction. Under non-highway driving (NHD), several of the tested China IV diesel trucks experienced no reduction or an increase in NOx emissions compared to their China III counterparts. The NOx emissions factors of the 18 tested diesel trucks under NHD were on average 1.5-times greater than those under highway driving (HD), and the effects on NOx emissions removal from China III to China IV diesel trucks were greater under HD than under NHD. In addition, no significant reduction of NOx based on fuel consumption for China IV diesel trucks was observed for MDDTs and HDDTs compared to the test results for similar China II vehicles reported in a previous study. To reduce NOx emissions in China, additional control measures of vehicular NOx emissions should be formulated.

40 CFR 94.305 - Credit generation and use calculation.

Code of Federal Regulations, 2013 CFR

2013-07-01

... engine family, calculate THC+NOX and PM emission credits (positive or negative) according to the equation... applicable cycle-weighted marine engine THC+NOX or PM emission standard in grams per kilowatt-hour. (ii) FEL...

40 CFR 94.305 - Credit generation and use calculation.

Code of Federal Regulations, 2011 CFR

2011-07-01

... engine family, calculate THC+NOX and PM emission credits (positive or negative) according to the equation... applicable cycle-weighted marine engine THC+NOX or PM emission standard in grams per kilowatt-hour. (ii) FEL...

40 CFR 94.305 - Credit generation and use calculation.

Code of Federal Regulations, 2012 CFR

2012-07-01

... engine family, calculate THC+NOX and PM emission credits (positive or negative) according to the equation... applicable cycle-weighted marine engine THC+NOX or PM emission standard in grams per kilowatt-hour. (ii) FEL...

40 CFR 94.305 - Credit generation and use calculation.

Code of Federal Regulations, 2014 CFR

2014-07-01

... engine family, calculate THC+NOX and PM emission credits (positive or negative) according to the equation... applicable cycle-weighted marine engine THC+NOX or PM emission standard in grams per kilowatt-hour. (ii) FEL...

40 CFR 94.305 - Credit generation and use calculation.

Code of Federal Regulations, 2010 CFR

2010-07-01

... engine family, calculate THC+NOX and PM emission credits (positive or negative) according to the equation... applicable cycle-weighted marine engine THC+NOX or PM emission standard in grams per kilowatt-hour. (ii) FEL...

N2O and NO2 Emissions from Heavy-Duty Diesel Trucks with Advanced Emission Controls

NASA Astrophysics Data System (ADS)

Preble, C.; Harley, R.; Kirchstetter, T.

2014-12-01

Diesel engines are the largest source of nitrogen oxides (NOx) emissions nationally, and also a major contributor to the black carbon (BC) fraction of fine particulate matter (PM). Recently, diesel particle filter (DPF) and selective catalytic reduction (SCR) emission control systems that target exhaust PM and NOx have become standard equipment on new heavy-duty diesel trucks. However, the deliberate catalytic oxidation of engine-out nitric oxide (NO) to nitrogen dioxide (NO2) in continuously regenerating DPFs leads to increased tailpipe emission of NO2. This is of potential concern due to the toxicity of NO2 and the resulting increases in atmospheric formation of other air pollutants such as ozone, nitric acid, and fine PM. While use of SCR reduces emissions of both NO and NO2, it may lead to increased emissions of nitrous oxide (N2O), a potent greenhouse gas. Here we report results from on-road measurements of heavy-duty diesel truck emissions conducted at the Port of Oakland and the Caldecott Tunnel in the San Francisco Bay Area. Emission factors (g pollutant per kg of diesel) were linked via recorded license plates to individual truck attributes, including engine model year and installed emission control equipment. Between 2009 and 2013, the fraction of DPF-equipped trucks at the Port of Oakland increased from 2 to 99%, and median engine age decreased from 11 to 6 years. Over the same period, fleet-average emission factors for black carbon and NOx decreased by 76 ± 22% and 53 ± 8%, respectively. However, direct emissions of NO2 increased, and consequently the NO2/NOx emission ratio increased from 0.03 ± 0.02 to 0.18 ± 0.03. Older trucks retrofitted with DPFs emitted approximately 3.5 times more NO2 than newer trucks equipped with both DPF and SCR. Preliminary data from summer 2014 measurements at the Caldecott Tunnel suggest that some older trucks have negative emission factors for N2O, and that for newer trucks, N2O emission factors have changed sign and are significantly increased. More comprehensive analysis of the effects of SCR on diesel NOx and N2O emissions will be reported in the presentation. These on-road emission studies indicate that advanced emission control systems such as DPF and SCR dramatically reduce PM and NOx emissions, but can cause undesirable side effects like increased NO2 and N2O emissions.

INDUSTRIAL BOILER RETROFIT FOR NOX CONTROL: COMBINED SELECTIVE NONCATALYTIC REDUCTION AND SELECTIVE CATALYTIC REDUCTION

EPA Science Inventory

The paper describes retrofitting and testing a 590 kW (2 MBtu/hr), oil-fired, three-pass, fire-tube package boiler with a combined selective noncatalytic reduction (SNCR) and selective catalytic reduction (SCR) system. The system demonstrated 85% nitrogen oxides (NOx) reduction w...

Observations of the temperature dependent response of ozone to NOx reductions in the Sacramento, CA urban plume

NASA Astrophysics Data System (ADS)

Lafranchi, B. W.; Goldstein, A. H.; Cohen, R. C.

2011-02-01

Observations of NOx in the Sacramento, CA region show that mixing ratios decreased by 30% between 2001 and 2008. Here we use an observation-based method to quantify net ozone production rates in the outflow from the Sacramento metropolitan region and examine the O3 decrease resulting from reductions in NOx emissions. This observational method does not rely on assumptions about detailed chemistry of ozone production, rather it is an independent means to verify and test these assumptions. We use an instantaneous steady-state model as well as a detailed 1-D plume model to aid in interpretation of the ozone production inferred from observations. In agreement with the models, the observations show that early in the plume, the NOx dependence for Ox (Ox = O3 + NO2) production is strongly coupled with temperature, suggesting that temperature-dependent biogenic VOC emissions can drive Ox production between NOx-limited and NOx-suppressed regimes. As a result, NOx reductions were found to be most effective at higher temperatures over the 7 year period. We show that violations of the California 1-hour O3 standard (90 ppb) in the region have been decreasing linearly with decreases in NOx (at a given temperature) and predict that reductions of NOx concentrations (and presumably emissions) by an additional 30% (relative to 2007 levels) will eliminate violations of the state 1 h standard in the region. If current trends continue, a 30% decrease in NOx is expected by 2012, and an end to violations of the 1 h standard in the Sacramento region appears to be imminent.

High-Potential Electrocatalytic O2 Reduction with Nitroxyl / NOx Mediators: Implications for Fuel Cells and Aerobic Oxidation Catalysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gerken, James B.; Stahl, Shannon S.

2015-07-15

Efficient reduction of O2 to water is a central challenge in energy conversion and aerobic oxidation catalysis. In the present study, we investigate the electrochemical reduction of O2 with soluble organic nitroxyl and nitrogen oxide (NOx) mediators. When used alone, neither organic nitroxyls, such as TEMPO (2,2,6,6-tetramethyl-1-piperidinyl-N-oxyl), nor NOx species, such as sodium nitrite, are effective mediators of electrochemical O2 reduction. The combination of nitroxyl/NOx species, however, mediates sustained O2 reduction at electrochemical potentials of 0.19–0.33 V (vs. Fc/Fc+) in acetonitrile containing trifluoroacetic acid. Mechanistic analysis of the coupled redox reactions supports a process in which the nitrogen oxide catalystmore » drives aerobic oxidation of a nitroxyl mediator to an oxoammonium species, which then is reduced back to the nitroxyl at the cathode. The electrolysis potential is dictated by the oxoammonium/nitroxyl reduction potential. The high potentials observed with this ORR system benefit from the mechanism-based specificity for four-electron reduction of oxygen to water mediated by NOx species, together with kinetically efficient reduction of oxidized NOx species by TEMPO and other organic nitroxyls. This research was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center, funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences.« less

The Reduction of NOx Using Pulsed Electron Beams

DTIC Science & Technology

2015-12-30

flue gas (SFG) is described. The SFG is a simulant for exhaust flue gas from a coal combustion power plant. The technology utilizes a pulsed electron...a surrogate flue gas (SFG) is described. The SFG simulates exhaust flue gas from a coal combustion power plant. The technology utilizes a pulsed...temperature combustion in air-breathing engines and coal power plants. The gases are also produced in nature during thunderstorms by lightning

Experimental Study on Relationship between NOx Emission and Fuel Consumption of a Diesel Engine

NASA Astrophysics Data System (ADS)

Ning, Ping; Liu, Chunjiang; Feng, Zhiqiang; Xia, Yijiang

2018-01-01

For YC6112 diesel engine assembled Delphl model single fuel pump electric controlled, in the premise of not changing its overall unit structure parameters of other systems, three different types of camshaft for single pumps, two kinds of fuel injectors, two types of superchargers and some phase shifting angle of different camshafts were chosen to match with the engine precisely, the experiments under thirteen kinds of working conditions for the engine with different matching were carried out, the change regulation between NOX emission and fuel consumption for the engine with different kinds of configurations was analyzed. The experiment results show the NOX emission and fuel consumption can be reduced greatly by configuring proper camshaft, fuel injectors and superchargers with YC6112 diesel engine.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boyd, Rodney

The objective of this project was to define the scope and cost of a technology research and development program that will demonstrate the feasibility of using an off-the-shelf, unmodified, large bore diesel powered generator in a grid-connected application, utilizing various blends of BioDiesel as fuel. Furthermore, the objective of project was to develop an emissions control device that uses a catalytic process and BioDiesel (without the presence of Ammonia or Urea)to reduce NOx and other pollutants present in a reciprocating engine exhaust stream with the goal of redefining the highest emission reduction efficiencies possible for a diesel reciprocating generator. Process:more » Caterpillar Power Generation adapted an off-the-shelf Diesel Generator to run on BioDiesel and various Petroleum Diesel/BioDiesel blends. EmeraChem developed and installed an exhaust gas cleanup system to reduce NOx, SOx, volatile organics, and particulates. The system design and function was optimized for emissions reduction with results in the 90-95% range;« less

Introducing the VRT gas turbine combustor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Melconian, J.O.; Mostafa, A.A.; Nguyen, H.L.

An innovative annular combustor configuration is being developed for aircraft and other gas turbine engines. This design has the potential of permitting higher turbine inlet temperatures by reducing the pattern factor and providing a major reduction in NO(x) emission. The design concept is based on a Variable Residence Time (VRT) technique which allows large fuel particles adequate time to completely burn in the circumferentially mixed primary zone. High durability of the combustor is achieved by dual function use of the incoming air. The feasibility of the concept was demonstrated by water analogue tests and 3-D computer modeling. The computer modelmore » predicted a 50 percent reduction in pattern factor when compared to a state of the art conventional combustor. The VRT combustor uses only half the number of fuel nozzles of the conventional configuration. The results of the chemical kinetics model require further investigation, as the NO(x) predictions did not correlate with the available experimental and analytical data base.« less

DI Diesel Performance and Emissions Models

DTIC Science & Technology

2003-06-11

Skeletal mechanism for NOx chemistry in diesel engines ,” SAE Paper 981450, 1998 SAE Transactions, Vol. 107, Sect. 4, J. Fuels and... mechanism for NOx chemistry proposed by Mellor et al. (1998a) is incorporated in an engine simulation code. The two-zone model, also proposed by Mellor et...34Dynamic Application of a Skeletal Mechanism for DI Diesel NOx Emissions," SAE Paper 2001-01-1984, SAE Trans., J. Fuels & Lubricants,

Correlating Engine NOx Emission with Biodiesel Composition

NASA Astrophysics Data System (ADS)

Jeyaseelan, Thangaraja; Mehta, Pramod Shankar

2017-06-01

Biodiesel composition comprising of saturated and unsaturated fatty acid methyl esters has a significant influence on its properties and hence the engine performance and emission characteristics. This paper proposes a comprehensive approach for composition-property-NOx emission analysis for biodiesel fuels and highlights the pathways responsible for such a relationship. Finally, a procedure and a predictor equation are developed for the assessment of biodiesel NOx emission from its composition details.

Climate and environmental effects of electric vehicles versus compressed natural gas vehicles in China: a life-cycle analysis at provincial level.

PubMed

Huo, Hong; Zhang, Qiang; Liu, Fei; He, Kebin

2013-02-05

Electric vehicles (EVs) and compressed natural gas vehicles (CNGVs), which are mainly coal-based and natural gas-based, are the two most widely proposed replacements of gasoline internal combustion engine vehicles (ICEVs) in P.R. China. We examine fuel-cycle emissions of greenhouse gases (GHGs), PM(2.5), PM(10), NO(x), and SO(2) of CNGVs and EVs relative to gasoline ICEVs and hybrids, by Chinese province. CNGVs can currently reduce emissions of GHGs, PM(10), PM(2,5), NO(x), and SO(2) by approximately 6%, 7%, 20%, 18% and 22%, respectively. EVs can reduce GHG emissions by 20%, but increase PM(10), PM(2.5), NO(x), and SO(2) emissions by approximately 360%, 250%, 120%, and 370%, respectively. Nevertheless, results vary significantly by province. Regarding their contribution to national emissions, PM increases from EVs are unimportant, because light-duty passenger vehicles contribute very little to overall PM emissions nationwide (≤0.05%); however, their NO(x) and SO(2) increases are important. Since China is striving to reduce power plant emissions, EVs are expected to have equivalent or even lower SO(2) and NO(x) emissions relative to ICEVs in the future (2030). Before then, however, EVs should be developed according to the cleanness of regional power mixes. This would lower their SO(2) and NO(x) emissions and earn more GHG reduction credits.

40 CFR 1045.701 - General provisions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... engines or fuel-system components not participating in the ABT program of this subpart. (9) Trade means to... watercraft engines. (d) Sterndrive/inboard engines certified under § 1045.660 for jet boats may use HC+NOX... trading. The FEL caps for such jet boat families are the HC+NOX and CO standard for outboard and personal...

40 CFR 1045.701 - General provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... engines or fuel-system components not participating in the ABT program of this subpart. (9) Trade means to... watercraft engines. (d) Sterndrive/inboard engines certified under § 1045.660 for jet boats may use HC+NOX... trading. The FEL caps for such jet boat families are the HC+NOX and CO standard for outboard and personal...

40 CFR 1045.701 - General provisions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... engines or fuel-system components not participating in the ABT program of this subpart. (9) Trade means to... watercraft engines. (d) Sterndrive/inboard engines certified under § 1045.660 for jet boats may use HC+NOX... trading. The FEL caps for such jet boat families are the HC+NOX and CO standard for outboard and personal...

Aftertreatment Technologies for Off-Highway Heavy-Duty Diesel Engines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kass, M.D.

2008-07-15

The objective of this program was to explore a combination of advanced injection control and urea-selective catalytic reduction (SCR) to reduce the emissions of oxides of nitrogen (NOx) and particulate matter (PM) from a Tier 2 off-highway diesel engine to Tier 3 emission targets while maintaining fuel efficiency. The engine used in this investigation was a 2004 4.5L John Deere PowerTechTM; this engine was not equipped with exhaust gas recirculation (EGR). Under the original CRADA, the principal objective was to assess whether Tier 3 PM emission targets could be met solely by increasing the rail pressure. Although high rail pressuremore » will lower the total PM emissions, it has a contrary effect to raise NOx emissions. To address this effect, a urea-SCR system was used to determine whether the enhanced NOx levels, associated with high rail pressure, could be reduced to Tier 3 levels. A key attraction for this approach is that it eliminates the need for a Diesel particulate filter (DPF) to remove PM emissions. The original CRADA effort was also performed using No.2 Diesel fuel having a maximum sulfur level of 500 ppm. After a few years, the CRADA scope was expanded to include exploration of advanced injection strategies to improve catalyst regeneration and to explore the influence of urea-SCR on PM formation. During this period the emission targets also shifted to meeting more stringent Tier 4 emissions for NOx and PM, and the fuel type was changed to ultra-low sulfur Diesel (ULSD) having a maximum sulfur concentration of 15 ppm. New discoveries were made regarding PM formation at high rail pressures and the influences of oxidation catalysts and urea-SCR catalysts. These results are expected to provide a pathway for lower PM and NOx emissions for both off- and on-highway applications. Industrial in-kind support was available throughout the project period. Review of the research results were carried out on a regular basis (annual reports and meetings) followed by suggestions for improvement in ongoing work and direction for future work. A significant portion of the industrial support was in the form of experimentation, data analysis, data exchange, and technical consultation.« less

Emission reduction from a diesel engine fueled by pine oil biofuel using SCR and catalytic converter

NASA Astrophysics Data System (ADS)

Vallinayagam, R.; Vedharaj, S.; Yang, W. M.; Saravanan, C. G.; Lee, P. S.; Chua, K. J. E.; Chou, S. K.

2013-12-01

In this work, we propose pine oil biofuel, a renewable fuel obtained from the resins of pine tree, as a potential substitute fuel for a diesel engine. Pine oil is endowed with enhanced physical and thermal properties such as lower viscosity and boiling point, which enhances the atomization and fuel/air mixing process. However, the lower cetane number of the pine oil hinders its direct use in diesel engine and hence, it is blended in suitable proportions with diesel so that the ignition assistance could be provided by higher cetane diesel. Since lower cetane fuels are prone to more NOX formation, SCR (selective catalyst reduction), using urea as reducing agent, along with a CC (catalytic converter) has been implemented in the exhaust pipe. From the experimental study, the BTE (brake thermal efficiency) was observed to be increased as the composition of pine oil increases in the blend, with B50 (50% pine oil and 50% diesel) showing 7.5% increase over diesel at full load condition. The major emissions such as smoke, CO, HC and NOX were reduced by 70.1%, 67.5%, 58.6% and 15.2%, respectively, than diesel. Further, the average emissions of B50 with SCR and CC assembly were observed to be reduced, signifying the positive impact of pine oil biofuel on atmospheric environment. In the combustion characteristics front, peak heat release rate and maximum in-cylinder pressure were observed to be higher with longer ignition delay.

A study of a direct-injection stratified-charge rotary engine for motor vehicle application

NASA Astrophysics Data System (ADS)

Kagawa, Ryoji; Okazaki, Syunki; Somyo, Nobuhiro; Akagi, Yuji

1993-03-01

A study of a direct-injection stratified-charge system (DISC), as applied to a rotary engine (RE) for motor vehicle usage, was undertaken. The goals of this study were improved fuel consumption and reduced exhaust emissions. These goals were thought feasible due to the high thermal efficiency associated with the DISC-RE. This was the first application of this technology to a motor vehicle engine. Stable ignition and ideal stratification systems were developed by means of numerical calculations, air-fuel mixture measurements, and actual engine tests. The use of DISC resulted in significantly improved fuel consumption and reduced exhaust emissions. The use of an exhaust gas recirculating system was studied and found to be beneficial in NOx reduction.

Parametric (On-Design) Cycle Analysis for a Separate-Exhaust Turbofan Engine With Interstage Turbine Burner

NASA Technical Reports Server (NTRS)

Liew, K. H.; Urip, E.; Yang, S. L.; Siow, Y. K.; Marek, C. J.

2005-01-01

Today s modern aircraft is based on air-breathing jet propulsion systems, which use moving fluids as substances to transform energy carried by the fluids into power. Throughout aero-vehicle evolution, improvements have been made to the engine efficiency and pollutants reduction. The major advantages associated with the addition of ITB are an increase in thermal efficiency and reduction in NOx emission. Lower temperature peak in the main combustor results in lower thermal NOx emission and lower amount of cooling air required. This study focuses on a parametric (on-design) cycle analysis of a dual-spool, separate-flow turbofan engine with an Interstage Turbine Burner (ITB). The ITB considered in this paper is a relatively new concept in modern jet engine propulsion. The ITB serves as a secondary combustor and is located between the high- and the low-pressure turbine, i.e., the transition duct. The objective of this study is to use design parameters, such as flight Mach number, compressor pressure ratio, fan pressure ratio, fan bypass ratio, and high-pressure turbine inlet temperature to obtain engine performance parameters, such as specific thrust and thrust specific fuel consumption. Results of this study can provide guidance in identifying the performance characteristics of various engine components, which can then be used to develop, analyze, integrate, and optimize the system performance of turbofan engines with an ITB. Visual Basic program, Microsoft Excel macrocode, and Microsoft Excel neuron code are used to facilitate Microsoft Excel software to plot engine performance versus engine design parameters. This program computes and plots the data sequentially without forcing users to open other types of plotting programs. A user s manual on how to use the program is also included in this report. Furthermore, this stand-alone program is written in conjunction with an off-design program which is an extension of this study. The computed result of a selected design-point engine will be exported to an engine reference data file that is required in off-design calculation.

Observations of the temperature dependent response of ozone to NOx reductions in the Sacramento, CA urban plume

NASA Astrophysics Data System (ADS)

Lafranchi, B. W.; Goldstein, A. H.; Cohen, R. C.

2011-07-01

Observations of NOx in the Sacramento, CA region show that mixing ratios decreased by 30 % between 2001 and 2008. Here we use an observation-based method to quantify net ozone (O3) production rates in the outflow from the Sacramento metropolitan region and examine the O3 decrease resulting from reductions in NOx emissions. This observational method does not rely on assumptions about detailed chemistry of ozone production, rather it is an independent means to verify and test these assumptions. We use an instantaneous steady-state model as well as a detailed 1-D plume model to aid in interpretation of the ozone production inferred from observations. In agreement with the models, the observations show that early in the plume, the NOx dependence for Ox (Ox = O3 + NO2) production is strongly coupled with temperature, suggesting that temperature-dependent biogenic VOC emissions and other temperature-related effects can drive Ox production between NOx-limited and NOx-suppressed regimes. As a result, NOx reductions were found to be most effective at higher temperatures over the 7 year period. We show that violations of the California 1-h O3 standard (90 ppb) in the region have been decreasing linearly with decreases in NOx (at a given temperature) and predict that reductions of NOx concentrations (and presumably emissions) by an additional 30 % (relative to 2007 levels) will eliminate violations of the state 1 h standard in the region. If current trends continue, a 30 % decrease in NOx is expected by 2012, and an end to violations of the 1 h standard in the Sacramento region appears to be imminent.

Engine Conceptual Design Studies for a Hybrid Wing Body Aircraft

NASA Technical Reports Server (NTRS)

Tong, Michael T.; Jones, Scott M.; Haller, William J.; Handschuh, Robert F.

2009-01-01

Worldwide concerns of air quality and climate change have made environmental protection one of the most critical issues in aviation today. NASA's current Fundamental Aeronautics research program is directed at three generations of aircraft in the near, mid and far term, with initial operating capability around 2015, 2020, and 2030, respectively. Each generation has associated goals for fuel burn, NOx, noise, and field-length reductions relative to today's aircrafts. The research for the 2020 generation is directed at enabling a hybrid wing body (HWB) aircraft to meet NASA's aggressive technology goals. This paper presents the conceptual cycle and mechanical designs of the two engine concepts, podded and embedded systems, which were proposed for a HWB cargo freighter. They are expected to offer significant benefits in noise reductions without compromising the fuel burn.

Experimental Assessment of NOx Emissions from 73 Euro 6 Diesel Passenger Cars.

PubMed

Yang, Liuhanzi; Franco, Vicente; Mock, Peter; Kolke, Reinhard; Zhang, Shaojun; Wu, Ye; German, John

2015-12-15

Controlling nitrogen oxides (NOx) emissions from diesel passenger cars during real-world driving is one of the major technical challenges facing diesel auto manufacturers. Three main technologies are available for this purpose: exhaust gas recirculation (EGR), lean-burn NOx traps (LNT), and selective catalytic reduction (SCR). Seventy-three Euro 6 diesel passenger cars (8 EGR only, 40 LNT, and 25 SCR) were tested on a chassis dynamometer over both the European type-approval cycle (NEDC, cold engine start) and the more realistic Worldwide harmonized light-duty test cycle (WLTC version 2.0, hot start) between 2012 and 2015. Most vehicles met the legislative limit of 0.08 g/km of NOx over NEDC (average emission factors by technology: EGR-only 0.07 g/km, LNT 0.04 g/km, and SCR 0.05 g/km), but the average emission factors rose dramatically over WLTC (EGR-only 0.17 g/km, LNT 0.21 g/km, and SCR 0.13 g/km). Five LNT-equipped vehicles exhibited very poor performance over the WLTC, emitting 7-15 times the regulated limit. These results illustrate how diesel NOx emissions are not properly controlled under the current, NEDC-based homologation framework. The upcoming real-driving emissions (RDE) regulation, which mandates an additional on-road emissions test for EU type approvals, could be a step in the right direction to address this problem.

On-road, in-use gaseous emission measurements by remote sensing of school buses equipped with diesel oxidation catalysts and diesel particulate filters.

PubMed

Burgard, Daniel A; Provinsal, Melissa N

2009-12-01

A remote sensing device was used to obtain on-road and in-use gaseous emission measurements from three fleets of schools buses at two locations in Washington State. This paper reports each fleet's carbon monoxide (CO), hydrocarbon (HC), nitric oxide (NO), and nitrogen dioxide (NO2) mean data. The fleets represent current emission retrofit technologies, such as diesel particulate filters and diesel oxidation catalysts, and a control fleet. This study shows that CO and HC emissions decrease with the use of either retrofit technology when compared with control buses of the same initial emission standards. The CO and HC emission reductions are consistent with published U.S. Environmental Protection Agency verified values. The total oxides of nitrogen (NOx), NO, and the NO2/NOx ratio all increase with each retrofit technology when compared with control buses. As was expected, the diesel particulate filters emitted significantly higher levels of NO2 than the control fleet because of the intentional conversion of NO to NO2 by these systems. Most prior research suggests that NOx emissions are unaffected by the retrofits; however, these previous studies have not included measurements from retrofit devices on-road and after nearly 5 yr of use. Two 2006 model-year buses were also measured. These vehicles did not have retrofit devices but were built to more stringent new engine standards. Reductions in HCs and NOx were observed for these 2006 vehicles in comparison to other non-retrofit earlier model-year vehicles.

Observational constraints on projections of the ozone response to NOx controls in the Southern San Joaquin Valley

NASA Astrophysics Data System (ADS)

Pusede, S. E.; Wooldridge, P. J.; Browne, E. C.; Russell, A. R.; Rollins, A.; Min, K.; Thomas, J.; Zhang, L.; Brune, W. H.; Henry, S. B.; DiGangi, J. P.; Keutsch, F. N.; Sanders, J. E.; Ren, X.; Weber, R.; Goldstein, A. H.; Cohen, R. C.

2011-12-01

We investigate the impact of NOx reductions on ozone production in the Southern San Joaquin Valley using a large suite of radical and trace gas measurements collected during CalNex-2010 in Bakersfield, California (May 15-June 28) combined with the historical record of O3, nitrogen oxides and temperature from CARB monitoring sites in the region. We calculate the instantaneous ozone production rate (PO3) by radical balance and investigate relationships between PO3 and NOx abundance; finding temperature to be a useful proxy for VOC reactivity. We show Bakersfield photochemistry is at peak PO3 and therefore at a minimum with respect to the effectiveness of NOx controls indicating: (1) more than 30% reductions from present day are required before sizable decreases in ozone will occur and (2) reduction from the lower weekend baseline NOx concentrations will result in weekend PO3 decreases with continued NOx controls at high temperatures when VOC reactivity is largest.

Impact of alternative fuels on emissions characteristics of a gas turbine engine - part 1: gaseous and particulate matter emissions.

PubMed

Lobo, Prem; Rye, Lucas; Williams, Paul I; Christie, Simon; Uryga-Bugajska, Ilona; Wilson, Christopher W; Hagen, Donald E; Whitefield, Philip D; Blakey, Simon; Coe, Hugh; Raper, David; Pourkashanian, Mohamed

2012-10-02

Growing concern over emissions from increased airport operations has resulted in a need to assess the impact of aviation related activities on local air quality in and around airports, and to develop strategies to mitigate these effects. One such strategy being investigated is the use of alternative fuels in aircraft engines and auxiliary power units (APUs) as a means to diversify fuel supplies and reduce emissions. This paper summarizes the results of a study to characterize the emissions of an APU, a small gas turbine engine, burning conventional Jet A-1, a fully synthetic jet fuel, and other alternative fuels with varying compositions. Gas phase emissions were measured at the engine exit plane while PM emissions were recorded at the exit plane as well as 10 m downstream of the engine. Five percent reduction in NO(x) emissions and 5-10% reduction in CO emissions were observed for the alternative fuels. Significant reductions in PM emissions at the engine exit plane were achieved with the alternative fuels. However, as the exhaust plume expanded and cooled, organic species were found to condense on the PM. This increase in organic PM elevated the PM mass but had little impact on PM number.

Simultaneous removal of NOx and SO2 from flue gas using combined Na2SO3 assisted electrochemical reduction and direct electrochemical reduction.

PubMed

Guo, Qingbin; He, Yi; Sun, Tonghua; Wang, Yalin; Jia, Jinping

2014-07-15

A method combining Na2SO3 assisted electrochemical reduction and direct electrochemical reduction using Fe(II)(EDTA) solution was proposed to simultaneously remove NOx and SO2 from flue gas. Activated carbon was used as catalyst to accelerate the process. This new system features (a) direct conversion of NOx and SO2 to harmless N2 and SO4(2-); (b) fast regeneration of Fe(II)(EDTA); (c) minimum use of chemical reagents; and (d) recovery of the reduction by-product (Na2SO4). Fe(II)(EDTA) solution was continuously recycled and reused during entire process, and no harmful waste was generated. Approximately 99% NOx and 98% SO2 were removed under the optimal condition. The stability test showed that the system operation was reliable. Copyright © 2014 Elsevier B.V. All rights reserved.

Low NO(x) potential of gas turbine engines

NASA Technical Reports Server (NTRS)

Tacina, Robert R.

1990-01-01

The purpose is to correlate emission levels of gas turbine engines. The predictions of NO(x) emissions are based on a review of the literature of previous low NO(x) combustor programs and analytical chemical kinetic calculations. Concepts included in the literature review consisted of lean-premixed-prevaporized (LPP), rich burn/quick quench/lean burn (RQL), and direct injection. The NO(x) emissions were found to be an exponential function of adiabatic combustion temperature over a wide range of inlet temperatures, pressures and (lean) fuel-air ratios. A simple correlation of NO(x) formation with time was not found. The LPP and direct injection (using gaseous fuels) concepts have the lowest NO(x) emissions of the three concepts. The RQL data has higher values of NO(x) than the LPP concept, probably due to the stoichiometric temperatures and NO(x) production that occur during the quench step. Improvements in the quick quench step could reduce the NO(x) emissions to the LPP levels. The low NO(x) potential of LPP is offset by the operational disadvantages of its narrow stability limits and its susceptibility to autoignition/flashback. The Rich-Burn/Quick-Quench/Lean-Burn (RQL) and the direct injection concepts have the advantage of wider stability limits comparable to conventional combustors.

Method And Apparatus For Regenerating Nox Adsorbers

DOEpatents

Driscoll, J. Joshua; Endicott, Dennis L.; Faulkner, Stephen A.; Verkiel, Maarten

2006-03-28

Methods and apparatuses for regenerating a NOx adsorber coupled with an exhaust of an engine. An actuator drives a throttle valve to a first position when regeneration of the NOx adsorber is desired. The first position is a position that causes the regeneration of the NOx adsorber. An actuator drives the throttle valve to a second position while regeneration of the NOx adsorber is still desired. The second position being a position that is more open than the first position and operable to regenerate a NOx adsorber.

Real-world energy use and emission rates for idling long-haul trucks and selected idle reduction technologies.

PubMed

Frey, H Christopher; Kuo, Po-Yao

2009-07-01

Long-haul freight trucks typically idle for 2000 or more hours per year, motivating interest in reducing idle fuel use and emissions using auxiliary power units (APUs) and shore-power (SP). Fuel-use rates are estimated based on electronic control unit (ECU) data for truck engines and measurements for APU engines. Engine emission factors were measured using a portable emission measurement system. Indirect emissions from SP were based on average utility grid emission factors. Base engine fuel use and APU and SP electrical load were analyzed for 20 trucks monitored for more than 1 yr during 2.76 million mi of activity within 42 U.S. states. The average base engine fuel use varied from 0.46 to 0.65 gal/hr. The average APU fuel use varied from 0.24 to 0.41 gal/hr. Fuel-use rates are typically lowest in mild weather, highest in hot or cold weather, and depend on engine speed (revolutions per minute [RPM]). Compared with the base engine, APU fuel use and emissions of carbon dioxide (CO2) and sulfur dioxide (SO2) are lower by 36-47%. Oxides of nitrogen (NO(x)) emissions are lower by 80-90%. Reductions in particulate matter (PM), carbon monoxide (CO), and hydrocarbon emissions vary from approximately 10 to over 50%. SP leads to more substantial reductions, except for SO2. The actual achievable reductions will be lower because only a fraction of base engine usage will be replaced by APUs, SP, or both. Recommendations are made for reducing base engine fuel use and emissions, accounting for variability in fuel use and emissions reductions, and further work to quantify real-world avoided fuel use and emissions.

DI Diesel Performance and Emissions Model

DTIC Science & Technology

1998-03-31

Skeletal mechanism for NOx chemistry in Diesel engines ," SAE Paper 981450. Mori, K. (1997), "Worldwide...Based on the review discussed above, Mellor et al. (1998) postulate a skeletal mechanism for NO chemistry in DI Diesel engines . This mechanism is... mechanism for NOx chemistry in Diesel engines ," SAE Paper 981450. Various Internal Ford Reports, Ford Motor Company, Dearborn, MI. 29

Final Rule for Control of Air Pollution from Aircraft and Aircraft Engines: Emission Standards and Test Procedures

EPA Pesticide Factsheets

EPA is amending the existing emission standards for oxides of nitrogen (NOx) for new commercial aircraft engines. These standards are equivalent to the NOx emission standards of the United Nations International Civil Aviation Organization (ICAO).

Series hybrid vehicles and optimized hydrogen engine design

NASA Astrophysics Data System (ADS)

Smith, J. R.; Aceves, S.; Vanblarigan, P.

1995-05-01

Lawrence Livermore, Sandia Livermore and Los Alamos National Laboratories have a joint project to develop an optimized hydrogen fueled engine for series hybrid automobiles. The major divisions of responsibility are: system analysis, engine design and kinetics modeling by LLNL; performance and emission testing, and friction reduction by SNL; computational fluid mechanics and combustion modeling by LANL. This project is a component of the Department of Energy, Office of Utility Technology, National Hydrogen Program. We report here on the progress on system analysis and preliminary engine testing. We have done system studies of series hybrid automobiles that approach the PNGV design goal of 34 km/liter (80 mpg), for 384 km (240 mi) and 608 km (380 mi) ranges. Our results indicate that such a vehicle appears feasible using an optimized hydrogen engine. The impact of various on-board storage options on fuel economy are evaluated. Experiments with an available engine at the Sandia Combustion Research Facility demonstrated NO(x) emissions of 10 to 20 ppm at an equivalence ratio of 0.4, rising to about 500 ppm at 0.5 equivalence ratio using neat hydrogen. Hybrid vehicle simulation studies indicate that exhaust NO(x) concentrations must be less than 180 ppm to meet the 0.2 g/mile California Air Resources Board ULEV or Federal Tier-2 emissions regulations. We have designed and fabricated a first generation optimized hydrogen engine head for use on an existing single cylinder Onan engine. This head currently features 14.8:1 compression ratio, dual ignition, water cooling, two valves and open quiescent combustion chamber to minimize heat transfer losses.

Regional on-road vehicle running emissions modeling and evaluation for conventional and alternative vehicle technologies.

PubMed

Frey, H Christopher; Zhai, Haibo; Rouphail, Nagui M

2009-11-01

This study presents a methodology for estimating high-resolution, regional on-road vehicle emissions and the associated reductions in air pollutant emissions from vehicles that utilize alternative fuels or propulsion technologies. The fuels considered are gasoline, diesel, ethanol, biodiesel, compressed natural gas, hydrogen, and electricity. The technologies considered are internal combustion or compression engines, hybrids, fuel cell, and electric. Road link-based emission models are developed using modal fuel use and emission rates applied to facility- and speed-specific driving cycles. For an urban case study, passenger cars were found to be the largest sources of HC, CO, and CO(2) emissions, whereas trucks contributed the largest share of NO(x) emissions. When alternative fuel and propulsion technologies were introduced in the fleet at a modest market penetration level of 27%, their emission reductions were found to be 3-14%. Emissions for all pollutants generally decreased with an increase in the market share of alternative vehicle technologies. Turnover of the light duty fleet to newer Tier 2 vehicles reduced emissions of HC, CO, and NO(x) substantially. However, modest improvements in fuel economy may be offset by VMT growth and reductions in overall average speed.

Ultra-Efficient Engine Technology (UEET) Program

NASA Technical Reports Server (NTRS)

Manthey, Lori A.

2001-01-01

The Ultra-Efficient Engine Technology (UEET) Program includes seven key projects that work with industry to develop and hand off revolutionary propulsion technologies that will enable future-generation vehicles over a wide range of flight speeds. A new program office, the Ultra-Efficient Engine Technology (UEET) Program Office, was formed at the NASA Glenn Research Center to manage an important National propulsion program for NASA. The Glenn-managed UEET Program, which began on October 1, 1999, includes participation from three other NASA centers (Ames, Goddard, and Langley), as well as five engine companies (GE Aircraft Engines, Pratt & Whitney, Honeywell, Allison/Rolls Royce, and Williams International) and two airplane manufacturers (the Boeing Company and Lockheed Martin Corporation). This 6-year, nearly $300 million program will address local air-quality concerns by developing technologies to significantly reduce nitrogen oxide (NOx) emissions. In addition, it will provide critical propulsion technologies to dramatically increase performance as measured in fuel burn reduction that will enable reductions of carbon dioxide (CO2) emissions. This is necessary to address the potential climate impact of long-term aviation growth.

Experiments on Nitrogen Oxide Production of Droplet Arrays Burning under Microgravity Conditions

NASA Astrophysics Data System (ADS)

Moesl, Klaus; Sattelmayer, Thomas; Kikuchi, Masao; Yamamoto, Shin; Yoda, Shinichi

The optimization of the combustion process is top priority in current aero-engine and aircraft development, particularly from the perspectives of high efficiency, minimized fuel consumption, and a sustainable exhaust gas production. Aero-engines are exclusively liquid-fueled with a strong correlation between the combustion temperature and the emissions of nitric oxide (NOX ). Due to safety concerns, the progress in NOX reduction has been much slower than in stationary gas turbines. In the past, the mixing intensity in the primary zone of aero-engine combustors was improved and air staging implemented. An important question for future aero-engine combustors, consequently, is how partial vaporization influences the NOX emissions of spray flames? In order to address this question, the combustion of partially vaporized, linear droplet arrays was studied experimentally under microgravity conditions. The influence of fuel pre-vaporization on the NOX emissions was assessed in a wide range. The experiments were performed in a drop tower and a sounding rocket campaign. The microgravity environment provided ideal experiment conditions without the disturbing ef-fect of natural convection. This allowed the study of the interacting phenomena of multi-phase flow, thermodynamics, and chemical kinetics. This way the understanding of the physical and chemical processes related to droplet and spray combustion could be improved. The Bremen drop tower (ZARM) was utilized for the precursor campaign in July 2008, which was com-prised of 30 drops. The sounding rocket experiments, which totaled a microgravity duration of 6 minutes, were finally performed on the flight of TEXUS-46 in November 2009. On both campaigns the "Japanese Combustion Module" (JCM) was used. It is a cooperative experi-ment on droplet array combustion between the Japan Aerospace Exploration Agency (JAXA) and ESA's (European Space Agency) research team, working on the combustion properties of partially premixed sprays. One droplet array consisted of five droplets (for sounding rocket) and 9 -17 droplets (for drop tower) of the hydrocarbon n-decane (C10 H22 ). While keeping the pressure at 1.0 bar (+/-20 mbar), the combustion chamber temperature and the fuel vaporization time were varied in the range of 300 -500 K and 0.5 -18 s, respectively. Consequently, the total amount of fuel, the local equivalence ratio Φ along the droplet array, and the dimensionless droplet spacing S/d0 , with d0 being the initial droplet diameter, were adapted. Ignition was initiated by a hot-wire igniter from one end of the droplet array. Representative gas samples were collected from every single combustion sequence after flame extinction and stored in specially treated gas sampling cylinders for their succeeding analysis on ground. Visual observation of the combustion process, as well as temperature and pressure logging, supported the scientific interpretation of the gas analysis. With an increase of the preheating temperature, NOX emissions increase due to a higher effec-tive flame temperatures. However, with an increasing pre-vaporization, NOX emissions become lower due to the dropping number and the dropping size of burning droplets, acting as hot spots. A correction for the effect of the preheating temperature was developed. It reveals the effect of pre-vaporization and shows that the NOX emissions are almost independent of it for near-stoichiometric operation. At overall lean conditions the NOX emissions drop non-linearly with the degree of vaporization. Up to now, this leads to the conclusion that a high degree of vaporization is required in order to achieve substantial NOX abatement.

Wide range operation of advanced low NOx aircraft gas turbine combustors

NASA Technical Reports Server (NTRS)

Roberts, P. B.; Fiorito, R. J.; Butze, H. F.

1978-01-01

The paper summarizes the results of an experimental test rig program designed to define and demonstrates techniques which would allow the jet-induced circulation and vortex air blast combustors to operate stably with acceptable emissions at simulated engine idle without compromise to the low NOx emissions under the high-altitude supersonic cruise condition. The discussion focuses on the test results of the key combustor modifications for both the simulated engine idle and cruise conditions. Several range-augmentation techniques are demonstrated that allow the lean-reaction premixed aircraft gas turbine combustor to operate with low NOx emissons at engine cruise and acceptable CO and UHC levels at engine idle. These techniques involve several combinations, including variable geometry and fuel switching designs.

Development of a Comprehensive Community Nitrogen Oxide Emissions Reduction Toolkit (CCNERT)

NASA Astrophysics Data System (ADS)

Sung, Yong Hoon

The main objective of this study is to research and develop a simplified tool to estimate energy use in a community and its associated effects on air pollution. This tool is intended to predict the impacts of selected energy conservation options and efficiency programs on emission reduction. It is intended to help local government and their residents understand and manage information collection and the procedures to be used. This study presents a broad overview of the community-wide energy use and NOx emissions inventory process. It also presents various simplified procedures to estimate each sector's energy use. In an effort to better understand community-wide energy use and its associated NOx emissions, the City of College Station, Texas, was selected as a case study community for this research. While one community might successfully reduce the production of NOx emissions by adopting electricity efficiency programs in its buildings, another community might be equally successful by changing the mix of fuel sources used to generate electricity, which is consumed by the community. In yet a third community low NOx automobiles may be mandated. Unfortunately, the impact and cost of one strategy over another changes over time as major sources of pollution are reduced. Therefore, this research proposes to help community planners answer these questions and to assist local communities with their NOx emission reduction plans by developing a Comprehensive Community NOx Emissions Reduction Toolkit (CCNERT). The proposed simplified tool could have a substantial impact on reducing NOx emission by providing decision-makers with a preliminary understanding about the impacts of various energy efficiency programs on emissions reductions. To help decision makers, this study has addressed these issues by providing a general framework for examining how a community's non-renewable energy use leads to NOx emissions, by quantifying each end-user's energy usage and its associated NOx emissions, and by evaluating the environmental benefits of various types of energy saving options.

Evaluation of emission toxicity of urban bus engines: compressed natural gas and comparison with liquid fuels.

PubMed

Turrio-Baldassarri, Luigi; Battistelli, Chiara Laura; Conti, Luigi; Crebelli, Riccardo; De Berardis, Barbara; Iamiceli, Anna Laura; Gambino, Michele; Iannaccone, Sabato

2006-02-15

Emissions from a spark-ignition (SI) heavy-duty (HD) urban bus engine with a three-way catalyst (TWC), fuelled with compressed natural gas (CNG), were chemically analyzed and tested for genotoxicity. The results were compared with those obtained in a previous study on an equivalent diesel engine, fuelled with diesel oil (D) and a blend of the same with 20% vegetable oil (B20). Experimental procedures were identical, so that emission levels of the CNG engine were exactly comparable to the ones of the diesel engine. The experimental design was focused on carcinogenic compounds and genotoxic activity of exhausts. The results obtained show that the SI CNG engine emissions, with respect to the diesel engine fuelled with D, were nearly 50 times lower for carcinogenic polycyclic aromatic hydrocarbons (PAHs), 20 times lower for formaldehyde, and more than 30 times lower for particulate matter (PM). A 20-30 fold reduction of genotoxic activity was estimated from tests performed. A very high reduction of nitrogen oxides (NO(X)) was also measured. The impact of diesel powered transport on urban air quality, and the potential benefits deriving from the use of CNG for public transport, are discussed.

Black carbon, particle number concentration and nitrogen oxide emission factors of random in-use vehicles measured with the on-road chasing method

NASA Astrophysics Data System (ADS)

Ježek, I.; Katrašnik, T.; Westerdahl, D.; Močnik, G.

2015-06-01

The chasing method was used in an on-road measurement campaign, and emission factors (EF) of black carbon (BC), particle number (PN) and nitrogen oxides (NOx) were determined for 139 individual vehicles of different types encountered on the roads. The aggregated results provide EFs for BC, NOx and PN for three vehicle categories: goods vehicles, gasoline and diesel passenger cars. This is the first on-road measurement study where BC EFs of numerous individual diesel cars were determined in real-world driving conditions. We found good agreement between EFs of goods vehicles determined in this campaign and the results of previous studies that used either chasing or remote sensing measurement techniques. The composition of the sampled car fleet determined from the national vehicle registry information is reflective of Eurostat statistical data on the Slovenian and European vehicle fleet. The median BC EF of diesel and gasoline cars that were in use for less than 5 years, decreased by 60 and 47% from those in use for 5-10 years, respectively, the median NOx and PN EFs, of goods vehicles that were in use for less than five years, decreased from those in use for 5-10 years by 52 and 67%, respectively. The influence of engine maximum power of the measured EFs showed an increase in NOx EF from least to more powerful vehicles with diesel engines. Finally a disproportionate contribution of high emitters to the total emissions of the measured fleet was found; the top 25% of emitting diesel cars contributed 63, 47 and 61% of BC, NOx and PN emissions respectively. With the combination of relatively simple on-road measurements with sophisticated post processing individual vehicles EF can be determined and useful information about the fleet emissions can be obtained by exactly representing vehicles which contribute disproportionally to vehicle fleet emissions; and monitor how the numerous emission reduction approaches are reflected in on-road driving conditions.

ERBS fuel addendum: Pollution reduction technology program small jet aircraft engines, phase 3

NASA Technical Reports Server (NTRS)

Bruce, T. W.; Davis, F. G.; Kuhn, T. E.; Mongia, H. C.

1982-01-01

A Model TFE731-2 engine with a low emission, variable geometry combustion system was tested to compare the effects of operating the engine on Commercial Jet-A aviation turbine fuel and experimental referee broad specification (ERBS) fuels. Low power emission levels were essentially identical while the high power NOx emission indexes were approximately 15% lower with the EBRS fuel. The exhaust smoke number was approximately 50% higher with ERBS at the takeoff thrust setting; however, both values were still below the EPA limit of 40 for the Model TFE731 engine. Primary zone liner wall temperature ran an average of 25 K higher with ERBS fuel than with Jet-A. The possible adoption of broadened proprties fuels for gas turbine applications is suggested.

Highly-basic large-pore zeolite catalysts for NOx reduction at low temperatures

DOEpatents

Penetrante, Bernardino M.; Brusasco, Raymond M.; Merritt, Bernard T.; Vogtlin, George E.

2004-02-03

A high-surface-area (greater than 600 m2/g), large-pore (pore size diameter greater than 6.5 angstroms), basic zeolite having a structure such as an alkali metal cation-exchanged Y-zeolite is employed to convert NO.sub.x contained in an oxygen-rich engine exhaust to N.sub.2 and O.sub.2. Preferably, the invention relates to a two-stage method and apparatus for NO.sub.x reduction in an oxygen-rich engine exhaust such as diesel engine exhaust that includes a plasma oxidative stage and a selective reduction stage. The first stage employs a non-thermal plasma treatment of NO.sub.x gases in an oxygen-rich exhaust and is intended to convert NO to NO.sub.2 in the presence of O.sub.2 and added hydrocarbons. The second stage employs a lean-NO.sub.x catalyst including the basic zeolite at relatively low temperatures to convert such NO.sub.2 to environmentally benign gases that include N.sub.2, CO.sub.2, and H.sub.2 O.

Neural network controller development and implementation for spark ignition engines with high EGR levels.

PubMed

Vance, Jonathan Blake; Singh, Atmika; Kaul, Brian C; Jagannathan, Sarangapani; Drallmeier, James A

2007-07-01

Past research has shown substantial reductions in the oxides of nitrogen (NOx) concentrations by using 10%-25% exhaust gas recirculation (EGR) in spark ignition (SI) engines (see Dudek and Sain, 1989). However, under high EGR levels, the engine exhibits strong cyclic dispersion in heat release which may lead to instability and unsatisfactory performance preventing commercial engines to operate with high EGR levels. A neural network (NN)-based output feedback controller is developed to reduce cyclic variation in the heat release under high levels of EGR even when the engine dynamics are unknown by using fuel as the control input. A separate control loop was designed for controlling EGR levels. The stability analysis of the closed-loop system is given and the boundedness of the control input is demonstrated by relaxing separation principle, persistency of excitation condition, certainty equivalence principle, and linear in the unknown parameter assumptions. Online training is used for the adaptive NN and no offline training phase is needed. This online learning feature and model-free approach is used to demonstrate the applicability of the controller on a different engine with minimal effort. Simulation results demonstrate that the cyclic dispersion is reduced significantly using the proposed controller when implemented on an engine model that has been validated experimentally. For a single cylinder research engine fitted with a modern four-valve head (Ricardo engine), experimental results at 15% EGR indicate that cyclic dispersion was reduced 33% by the controller, an improvement of fuel efficiency by 2%, and a 90% drop in NOx from stoichiometric operation without EGR was observed. Moreover, unburned hydrocarbons (uHC) drop by 6% due to NN control as compared to the uncontrolled scenario due to the drop in cyclic dispersion. Similar performance was observed with the controller on a different engine.

Experimental Study of Effect of EGR Rates on NOx and Smoke Emission of LHR Diesel Engine Fueled with Blends of Diesel and Neem Biodiesel

NASA Astrophysics Data System (ADS)

Modi, Ashishkumar Jashvantlal; Gosai, Dipak Chimangiri; Solanki, Chandresh Maheshchandra

2018-04-01

Energy conservation and efficiency have been the quest of engineers concerned with internal combustion engine. Theoretically, if the heat rejected could be reduced, then the thermal efficiency would be improved, at least up to the limit set by the second law of thermodynamics. For current work a ceramic coated twin cylinder water-cooled diesel engine using blends of diesel and Neem biodiesel as fuel was evaluated for its performance and exhaust emissions. Multi cylinder vertical water cooled self-governed diesel engine, piston, top surface of cylinder head and liners were fully coated with partially stabilized zirconia as ceramic material attaining an adiabatic condition. Previous studies have reported that combustion of Neem biodiesel emitted higher NOx, while hydrocarbon and smoke emissions were lower than conventional diesel fuel. Exhaust gas recirculation (EGR) is one of the techniques being used to reduce NOx emission from diesel engines; because it decreases both flame temperature and oxygen concentration in the combustion chamber. The stationary diesel engine was run in laboratory at a high load condition (85% of maximum load), fixed speed (2000 rpm) and various EGR rates of 5-40% (with 5% increment). Various measurements like fuel flow, exhaust temperature, exhaust emission measurement and exhaust smoke test were carried out. The results indicate improved fuel economy and reduced pollution levels for the low heat rejection (LHR) engine. The results showed that, at 5% EGR with TB10, both NOx and smoke opacity were reduced by 26 and 15%, respectively. Furthermore, TB20 along with 10% EGR was also able to reduce both NOx and smoke emission by 34 and 30%, respectively compared to diesel fuel without EGR.

LES of Sooting Flames

DTIC Science & Technology

2006-12-01

27], [28] on soot nucleation, and [29] on the soot formation in diesel engines . [27] discussed the unresolved problems in SOx, NOx , and soot...used LEM approach to study aerosol dynamics in engine exhaust plumes. Recently, [41] used detailed NOx mechanism combined with MOM to predict the...combustion engines . For instance, the laminar flamelet approach used by [43, 44, 45], allows the usage of a detailed chemical mechanism but is not

Emissions of NOx, particle mass and particle numbers from aircraft main engines, APU's and handling equipment at Copenhagen Airport

NASA Astrophysics Data System (ADS)

Winther, Morten; Kousgaard, Uffe; Ellermann, Thomas; Massling, Andreas; Nøjgaard, Jacob Klenø; Ketzel, Matthias

2015-01-01

This paper presents a detailed emission inventory for NOx, particle mass (PM) and particle numbers (PN) for aircraft main engines, APU's and handling equipment at Copenhagen Airport (CPH) based on time specific activity data and representative emission factors for the airport. The inventory has a high spatial resolution of 5 m × 5 m in order to be suited for further air quality dispersion calculations. Results are shown for the entire airport and for a section of the airport apron area ("inner apron") in focus. The methodology presented in this paper can be used to quantify the emissions from aircraft main engines, APU and handling equipment in other airports. For the entire airport, aircraft main engines is the largest source of fuel consumption (93%), NOx, (87%), PM (61%) and PN (95%). The calculated fuel consumption [NOx, PM, PN] shares for APU's and handling equipment are 5% [4%, 8%, 5%] and 2% [9%, 31%, 0%], respectively. At the inner apron area for handling equipment the share of fuel consumption [NOx, PM, PN] are 24% [63%, 75%, 2%], whereas APU and main engines shares are 43% [25%, 19%, 54%], and 33% [11%, 6%, 43%], respectively. The inner apron NOx and PM emission levels are high for handling equipment due to high emission factors for the diesel fuelled handling equipment and small for aircraft main engines due to small idle-power emission factors. Handling equipment is however a small PN source due to the low number based emission factors. Jet fuel sulphur-PM sensitivity calculations made in this study with the ICAO FOA3.0 method suggest that more than half of the PM emissions from aircraft main engines at CPH originate from the sulphur content of the fuel used at the airport. Aircraft main engine PN emissions are very sensitive to the underlying assumptions. Replacing this study's literature based average emission factors with "high" and "low" emission factors from the literature, the aircraft main engine PN emissions were estimated to change with a factor of 14.

Degradation of Nylon-6/Clay Nanocomposites in NO(x)

NASA Astrophysics Data System (ADS)

Shelley, J. S.; Devries, K. L.

2000-04-01

Nylon-6 is an important engineering polymer that, in its fully spherulitic (bulk) form, has many applications in gears, rollers, and other long life cycle components. In 1993, Toyota commercialized a nylon-6/clay nanocomposite out of which it produced the timing belt cover for the 1993 Camry. Although these hybrid nanocomposites show significant improvements in their mechanical response characteristics, including yield strength and heat distortion temperature, little is known about the degradation of these properties due to environmental pollutants like NOx. Nylon-6 fibers are severely degraded by interaction with NOx and other pollutants, showing a strong synergism between applied load and environmental degradation. While the nanocomposites show a significant reduction in permeability of gases and water due to the incorporation of lamellar clay, their susceptibility to non-diffusional mechano-chemical degradation is unknown. The fracture toughness of these nylon-6/day nanocomposites increases, not as a function of clay content, but as a function of the volume of nylon-6 polymer chains influenced by the clay lamellar surfaces. Both the clay and the constrained volume offer the nanocomposites some protection from the deleterious effects of NOx. The time-to-failure at a given stress intensity factor as a function of clay content and constrained volume will be discussed along with fracture toughness of the materials.

40 CFR 86.327-79 - Quench checks; NOX analyzer.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission Regulations for New Gasoline-Fueled and Diesel-Fueled Heavy-Duty Engines; Gaseous Exhaust Test Procedures § 86.327-79..., recalibrate and repeat the quench check. (4) Prior to testing, the difference between the calculated NOX...

40 CFR 86.327-79 - Quench checks; NOX analyzer.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission Regulations for New Gasoline-Fueled and Diesel-Fueled Heavy-Duty Engines; Gaseous Exhaust Test Procedures § 86.327-79..., recalibrate and repeat the quench check. (4) Prior to testing, the difference between the calculated NOX...

The impact of using biodiesel/marine gas oil blends on exhaust emissions from a stationary diesel engine.

PubMed

Karavalakis, G; Tzirakis, E; Mattheou, L; Stournas, S; Zannikos, F; Karonis, D

2008-12-01

The purpose of this work was to investigate the impact of marine gas oil (MGO)/biodiesel blends on the exhaust emissions and fuel consumption in a single cylinder, stationary, diesel engine. Three different origins of biodiesel were used as the blending feedstock with the reference MGO, at proportions of 5 and 10% by volume. Methyl esters were examined according to the automotive FAME standard EN 14214. The baseline MGO and biodiesel blends were examined according to ISO 8217:2005 specifications for the DMA category. Independently of the biodiesel used, a decrease of PM, HC, CO and CO(2) emissions was observed. Emissions of NO(x) were also lower with respect to MGO. This reduction in NO(x) may be attributed to some physicochemical properties of the fuels applied, such as the higher cetane number and the lower volatility of methyl esters. Reductions in PM for biodiesel blends were lower in the exhaust than those of the reference fuel which was attributed to the oxygen content and the near absence of sulphur and aromatics compounds in biodiesel. However, a slight increase in fuel consumption was observed for the biodiesel blends that may be tolerated due to the exhaust emissions benefits. Brake thermal efficiency was also determined. Unregulated emissions were characterized by determining the soluble organic fraction content of the particulate matter.

Engine Conceptual Design Studies for a Hybrid Wing Body Aircraft

NASA Technical Reports Server (NTRS)

Tong, Michael T.; Jones, Scott M.; Haller, William J.; Handschuh, Robert F.

2009-01-01

Worldwide concerns of air quality and climate change have made environmental protection one of the most critical issues in aviation today. NASA s current Fundamental Aeronautics Research program is directed at three generations of aircraft in the near, mid and far term, with initial operating capability around 2015, 2020, and 2030, respectively. Each generation has associated goals for fuel burn, NOx, noise, and field-length reductions relative to today s aircrafts. The research for the 2020 generation is directed at enabling a hybrid wing body (HWB) aircraft to meet NASA s aggressive technology goals. This paper presents the conceptual cycle and mechanical designs of the two engine concepts, podded and embedded systems, which were proposed for a HWB cargo freighter. They are expected to offer significant benefits in noise reductions without compromising the fuel burn.

Effects of retrofitting emission control systems on in-use heavy diesel vehicles.

PubMed

Millstein, Dev E; Harley, Robert A

2010-07-01

Diesel engines are now the largest source of nitrogen oxides (NO(x)) and fine particulate black carbon (soot) emissions in California. The California Air Resources Board recently adopted a rule requiring that by 2014 all in-use heavy trucks and buses meet current (2007) exhaust particulate matter (PM) emission standards. Also by 2023 all in-use heavy-duty vehicles will have to meet current NO(x) emission standards, with significant progress in achieving the requirements for NO(x) control expected by 2014. This will require retrofit or replacement of older in-use engines. Diesel particle filters (DPF) reduce PM emissions but may increase the NO(2)/NO(x) emission ratio to approximately 35%, compared to approximately 5% typical of diesel engines without particle filters. Additionally, DPF with high oxidative capacity reduce CO and hydrocarbon emissions. We evaluate the effects of retrofitting trucks with DPF on air quality in southern California, using an Eulerian photochemical air quality model. Compared to a 2014 reference scenario without the retrofit program, black carbon concentrations decreased by 12 +/- 2% and 14 +/- 2% during summer and fall, respectively, with corresponding increases in ambient ozone concentrations of 3 +/- 2% and 7 +/- 3%. NO(2) concentrations decreased by 2-4% overall despite the increase in primary NO(2) emissions because total NO(x) emissions were reduced as part of the program to retrofit NO(x) control systems on in-use engines. However, in some cases NO(2) concentrations may increase at locations with high diesel truck traffic.

40 CFR 76.6 - NOX emission limitations for Group 2 boilers.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.6 NOX emission limitations..., the date on which the unit is required to meet Acid Rain emission reduction requirements for SO2, the...

40 CFR 76.6 - NOX emission limitations for Group 2 boilers.

Code of Federal Regulations, 2014 CFR

2014-07-01

... PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.6 NOX emission limitations..., the date on which the unit is required to meet Acid Rain emission reduction requirements for SO2, the...

40 CFR 76.6 - NOX emission limitations for Group 2 boilers.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.6 NOX emission limitations..., the date on which the unit is required to meet Acid Rain emission reduction requirements for SO2, the...

40 CFR 76.6 - NOX emission limitations for Group 2 boilers.

Code of Federal Regulations, 2013 CFR

2013-07-01

... PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.6 NOX emission limitations..., the date on which the unit is required to meet Acid Rain emission reduction requirements for SO2, the...

40 CFR 76.6 - NOX emission limitations for Group 2 boilers.

Code of Federal Regulations, 2012 CFR

2012-07-01

... PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.6 NOX emission limitations..., the date on which the unit is required to meet Acid Rain emission reduction requirements for SO2, the...

Low Emissions Aftertreatment and Diesel Emissions Reduction

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2005-05-27

Detroit Diesel Corporation (DDC) has successfully completed a five-year Low Emissions Aftertreatment and Diesel Emissions Reduction (LEADER) program under a DOE project entitled: ''Research and Development for Compression-Ignition Direct-Injection Engines (CIDI) and Aftertreatment Sub-Systems''. The objectives of the LEADER Program were to: Demonstrate technologies that will achieve future federal Tier 2 emissions targets; and Demonstrate production-viable technical targets for engine out emissions, efficiency, power density, noise, durability, production cost, aftertreatment volume and weight. These objectives were successfully met during the course of the LEADER program The most noteworthy achievements in this program are listed below: (1) Demonstrated Tier 2 Binmore » 3 emissions target over the FTP75 cycle on a PNGV-mule Neon passenger car, utilizing a CSF + SCR system These aggressive emissions were obtained with no ammonia (NH{sub 3}) slip and a combined fuel economy of 63 miles per gallon, integrating FTP75 and highway fuel economy transient cycle test results. Demonstrated feasibility to achieve Tier 2 Bin 8 emissions levels without active NOx aftertreatment. (2) Demonstrated Tier 2 Bin 3 emissions target over the FTP75 cycle on a light-duty truck utilizing a CSF + SCR system, synergizing efforts with the DOE-DDC DELTA program. This aggressive reduction in tailpipe out emissions was achieved with no ammonia slip and a 41% fuel economy improvement, compared to the equivalent gasoline engine-equipped vehicle. (3) Demonstrated Tier 2 near-Bin 9 emissions compliance on a light-duty truck, without active NOx aftertreatment devices, in synergy with the DOE-DDC DELTA program. (4) Developed and applied advanced combustion technologies such as ''CLEAN Combustion{copyright}'', which yields simultaneous reduction in engine out NOx and PM emissions while also improving engine and aftertreatment integration by providing favorable exhaust species and temperature characteristics. These favorable emissions characteristics were obtained while maintaining performance and fuel economy. These aggressive emissions and performance results were achieved by applying a robust systems technology development methodology. This systems approach benefits substantially from an integrated experimental and analytical approach to technology development, which is one of DDCs core competencies Also, DDC is uniquely positioned to undertake such a systems technology development approach, given its vertically integrated commercial structure within the DaimlerChrysler organization. State-of-the-art analytical tools were developed targeting specific LEADER program objectives and were applied to guide system enhancements and to provide testing directions, resulting in a shortened and efficient development cycle. Application examples include ammonia/NO{sub x} distribution improvement and urea injection controls development, and were key contributors to significantly reduce engine out as well as tailpipe out emissions. Successful cooperation between DDC and Engelhard Corporation, the major subcontractor for the LEADER program and provider of state-of-the-art technologies on various catalysts, was another contributing factor to ensure that both passenger car and LD truck applications achieved Tier 2 Bin 3 emissions levels. Significant technical challenges, which highlight barriers of commercialization of diesel technology for passenger cars and LD truck applications, are presented at the end of this report.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fang, Howard L.; Wang, Jerry C.; Yu, Robert C.

Sulfur poisoning from engine fuel and lube is one of the most recognizable degradation mechanisms of a NOx adsorber catalyst system for diesel emission reduction. Even with the availability of 15 ppm sulfur diesel fuel, NOx adsorber will be deactivated without an effective sulfur management. Two general pathways are currently being explored for sulfur management: (1) the use of a disposable SOx trap that can be replaced or rejuvenated offline periodically, and (2) the use of diesel fuel injection in the exhaust and high temperature de-sulfation approach to remove the sulfur poisons to recover the NOx trapping efficiency. The majormore » concern of the de-sulfation process is the many prolonged high temperature rich cycles that catalyst will encounter during its useful life. It is shown that NOx adsorber catalyst suffers some loss of its trapping capacity upon high temperature lean-rich exposure. With the use of a disposable SOx trap to remove large portion of the sulfur poisons from the exhaust, the NOx adsorber catalyst can be protected and the numbers of de-sulfation events can be greatly reduced. Spectroscopic techniques, such as DRIFTS and Raman, have been used to monitor the underlying chemical reactions during NOx trapping/ regeneration and de-sulfation periods, and provide a fundamental understanding of NOx storage capacity and catalyst degradation mechanism using model catalysts. This paper examines the sulfur effect on two model NOx adsorber catalysts. The chemistry of SOx/base metal oxides and the sulfation product pathways and their corresponding spectroscopic data are discussed. SAE Paper SAE-2003-01-3245 {copyright} 2003 SAE International. This paper is published on this website with permission from SAE International. As a user of this website, you are permitted to view this paper on-line, download this pdf file and print one copy of this paper at no cost for your use only. The downloaded pdf file and printout of this SAE paper may not be copied, distributed or forwarded to others or for the use of others.« less

Constitutive NADPH-dependent electron transferase activity of the Nox4 dehydrogenase domain.

PubMed

Nisimoto, Yukio; Jackson, Heather M; Ogawa, Hisamitsu; Kawahara, Tsukasa; Lambeth, J David

2010-03-23

NADPH oxidase 4 (Nox4) is constitutively active, while Nox2 requires the cytosolic regulatory subunits p47(phox) and p67(phox) and activated Rac with activation by phorbol 12-myristate 13-acetate (PMA). This study was undertaken to identify the domain on Nox4 that confers constitutive activity. Lysates from Nox4-expressing cells exhibited constitutive NADPH- but not NADH-dependent hydrogen peroxide production with a K(m) for NADPH of 55 +/- 10 microM. The concentration of Nox4 in cell lysates was estimated using Western blotting and allowed calculation of a turnover of approximately 200 mol of H(2)O(2) min(-1) (mol of Nox4)(-1). A chimeric protein (Nox2/4) consisting of the Nox2 transmembrane (TM) domain and the Nox4 dehydrogenase (DH) domain showed H(2)O(2) production in the absence of cytosolic regulatory subunits. In contrast, chimera Nox4/2, consisting of the Nox4 TM and Nox2 DH domains, exhibited PMA-dependent activation that required coexpression of regulatory subunits. Nox DH domains from several Nox isoforms were purified and evaluated for their electron transferase activities. Nox1 DH, Nox2 DH, and Nox5 DH domains exhibited barely detectable activities toward artificial electron acceptors, while the Nox4 DH domain exhibited significant rates of reduction of cytochrome c (160 min(-1), largely superoxide dismutase-independent), ferricyanide (470 min(-1)), and other electron acceptors (artificial dyes and cytochrome b(5)). Rates were similar to those observed for H(2)O(2) production by the Nox4 holoenzyme in cell lysates. The activity required added FAD and was seen with NADPH but not NADH. These results indicate that the Nox4 DH domain exists in an intrinsically activated state and that electron transfer from NADPH to FAD is likely to be rate-limiting in the NADPH-dependent reduction of oxygen by holo-Nox4.

40 CFR 76.5 - NOX emission limitations for Group 1 boilers.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.5 NOX emission limitations..., the date on which the unit is required to meet Acid Rain emission reduction requirements for SO2, the... 404(d) of the Act, the date the unit is required to meet Acid Rain emissions reduction requirements...

40 CFR 76.5 - NOX emission limitations for Group 1 boilers.

Code of Federal Regulations, 2012 CFR

2012-07-01

... PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.5 NOX emission limitations..., the date on which the unit is required to meet Acid Rain emission reduction requirements for SO2, the... 404(d) of the Act, the date the unit is required to meet Acid Rain emissions reduction requirements...

40 CFR 76.5 - NOX emission limitations for Group 1 boilers.

Code of Federal Regulations, 2013 CFR

2013-07-01

... PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.5 NOX emission limitations..., the date on which the unit is required to meet Acid Rain emission reduction requirements for SO2, the... 404(d) of the Act, the date the unit is required to meet Acid Rain emissions reduction requirements...

40 CFR 90.426 - Dilute emission sampling calculations-gasoline fueled engines.

Code of Federal Regulations, 2012 CFR

2012-07-01

... NOX) [g/kW-hr] Wi = Average mass flow rate of an emission (HC, CO, CO2, NOX) from a test engine during... is also equal to 1 for all two-stroke engines. (b) The mass flow rate, Wi in g/hr, of an emission for... rate, Fi, can be either measured or calculated using the following formula: ER03JY95.046 Where: MFUEL...

40 CFR 90.426 - Dilute emission sampling calculations-gasoline fueled engines.

Code of Federal Regulations, 2013 CFR

2013-07-01

... NOX) [g/kW-hr] Wi = Average mass flow rate of an emission (HC, CO, CO2, NOX) from a test engine during... is also equal to 1 for all two-stroke engines. (b) The mass flow rate, Wi in g/hr, of an emission for... rate, Fi, can be either measured or calculated using the following formula: ER03JY95.046 Where: MFUEL...

40 CFR 90.426 - Dilute emission sampling calculations-gasoline fueled engines.

Code of Federal Regulations, 2010 CFR

2010-07-01

... NOX) [g/kW-hr] Wi = Average mass flow rate of an emission (HC, CO, CO2, NOX) from a test engine during... is also equal to 1 for all two-stroke engines. (b) The mass flow rate, Wi in g/hr, of an emission for... rate, Fi, can be either measured or calculated using the following formula: ER03JY95.046 Where: MFUEL...

40 CFR 90.426 - Dilute emission sampling calculations-gasoline fueled engines.

Code of Federal Regulations, 2011 CFR

2011-07-01

... NOX) [g/kW-hr] Wi = Average mass flow rate of an emission (HC, CO, CO2, NOX) from a test engine during... is also equal to 1 for all two-stroke engines. (b) The mass flow rate, Wi in g/hr, of an emission for... rate, Fi, can be either measured or calculated using the following formula: ER03JY95.046 Where: MFUEL...

40 CFR 90.426 - Dilute emission sampling calculations-gasoline fueled engines.

Code of Federal Regulations, 2014 CFR

2014-07-01

... NOX) [g/kW-hr] Wi = Average mass flow rate of an emission (HC, CO, CO2, NOX) from a test engine during... is also equal to 1 for all two-stroke engines. (b) The mass flow rate, Wi in g/hr, of an emission for... rate, Fi, can be either measured or calculated using the following formula: ER03JY95.046 Where: MFUEL...

An Overview of Low-Emission Combustion Research

NASA Technical Reports Server (NTRS)

DelRosario, Ruben

2014-01-01

An overview of research efforts at NASA Glenn Research Center (GRC) in low-emission combustion technology that have made a significant impact on the Nitrogen Oxides (NOx) emission reduction in aircraft propulsion will be presented. The technology advancements and their impact on aircraft emissions will be discussed in the context of NASAs Aeronautics Research Mission Directorate (ARMD) high-level goals in fuel burn, noise and emission reductions. The highlights of the research presented will show how the past and current efforts have laid the foundation for the engines that are flying today as well as how the continued technology advancements will significantly influence the next generation of aviation propulsion system designs.

An Overview of Low-Emission Combustion Research at NASA Glenn

NASA Technical Reports Server (NTRS)

Reddy, Dhanireddy R.; Lee, Chi-Ming

2016-01-01

An overview of research efforts at NASA Glenn Research Center (GRC) in low-emission combustion technology that have made a significant impact on the nitrogen oxides (NOx) emission reduction in aircraft propulsion is presented. The technology advancements and their impact on aircraft emissions are discussed in the context of NASA's Aeronautics Research Mission Directorate (ARMD) high-level goals in fuel burn, noise and emission reductions. The highlights of the research presented here show how the past and current efforts laid the foundation for the engines that are flying today as well as how the continued technology advancements will significantly influence the next generation of aviation propulsion system designs.

Overview of Low Emission Combustion Research At NASA Glenn

NASA Technical Reports Server (NTRS)

Reddy, D. R.

2016-01-01

An overview of research efforts at NASA Glenn Research Center (GRC) in low-emission combustion technology that have made a significant impact on the nitrogen oxides (NOx) emission reduction in aircraft propulsion is presented. The technology advancements and their impact on aircraft emissions are discussed in the context of NASA's Aeronautics Research Mission Directorate (ARMD) high-level goals in fuel burn, noise and emission reductions. The highlights of the research presented here show how the past and current efforts laid the foundation for the engines that are flying today as well as how the continued technology advancements will significantly influence the next generation of aviation propulsion system designs.

Environmentally Responsible Aviation: Propulsion Research to Enable Fuel Burn, Noise and Emissions Reduction

NASA Technical Reports Server (NTRS)

Van Zante, Dale; Suder, Kenneth

2015-01-01

The NASA Environmentally Responsible Aviation (ERA) program is maturing technologies to enable simultaneous reduction of fuel burn, noise and emissions from an aircraft engine system. Three engine related Integrated Technology Demonstrations (ITDs) have been completed at Glenn Research Center in collaboration with Pratt Whitney, General Electric and the Federal Aviation Administration. The engine technologies being matured are: a low NOx, fuel flexible combustor in partnership with Pratt Whitney; an ultra-high bypass, ducted propulsor system in partnership with Pratt Whitney and FAA; and high pressure ratio, front-stage core compressor technology in partnership with General Electric. The technical rationale, test configurations and overall results from the test series in each ITD are described. ERA is using system analysis to project the benefits of the ITD technologies on potential aircraft systems in the 2025 timeframe. Data from the ITD experiments were used to guide the system analysis assumptions. Results from the current assessments for fuel burn, noise and oxides of nitrogen emissions are presented.

Environmentally Responsible Aviation: Propulsion Research to Enable Fuel Burn, Noise and Emissions Reduction

NASA Technical Reports Server (NTRS)

Van Zante, Dale E.; Suder, Kenneth L.

2015-01-01

The NASA Environmentally Responsible Aviation (ERA) program is maturing technologies to enable simultaneous reduction of fuel burn, noise and emissions from an aircraft engine system. Three engine related Integrated Technology Demonstrations (ITDs) have been completed at Glenn Research Center in collaboration with Pratt Whitney, General Electric and the Federal Aviation Administration. The engine technologies being matured are a low NOx, fuel flexible combustor in partnership with Pratt Whitney, an ultra-high bypass, ducted propulsor system in partnership with Pratt Whitney FAA and high pressure ratio, front-stage core compressor technology in partnership with General Electric. The technical rationale, test configurations and overall results from the test series in each ITD are described. ERA is using system analysis to project the benefits of the ITD technologies on potential aircraft systems in the 2025 timeframe. Data from the ITD experiments were used to guide the system analysis assumptions. Results from the current assessments for fuel burn, noise and oxides of nitrogen emissions are presented.

40 CFR Table 2 to Subpart Jjjj of... - Requirements for Performance Tests

Code of Federal Regulations, 2014 CFR

2014-07-01

... requirements 1. Stationary SI internal combustion engine demonstrating compliance according to § 60.4244. a. limit the concentration of NOX in the stationary SI internal combustion engine exhaust. i. Select the...) Alternatively, for NOX, O2, and moisture measurement, ducts ≤6 inches in diameter may be sampled at a single...

Evaluation of Ceramic Matrix Composite Technology for Aircraft Turbine Engine Applications

NASA Technical Reports Server (NTRS)

Halbig, Michael C.; Jaskowiak, Martha H.; Kiser, James D.; Zhu, Dongming

2013-01-01

The goals of the NASA Environmentally Responsible Aviation (ERA) Project are to reduce the NO(x) emissions, fuel burn, and noise from turbine engines. In order to help meet these goals, commercially-produced ceramic matrix composite (CMC) components and environmental barrier coatings (EBCs) are being evaluated as parts and panels. The components include a CMC combustor liner, a CMC high pressure turbine vane, and a CMC exhaust nozzle as well as advanced EBCs that are tailored to the operating conditions of the CMC combustor and vane. The CMC combustor (w/EBC) could provide 2700 F temperature capability with less component cooling requirements to allow for more efficient combustion and reductions in NOx emissions. The CMC vane (w/EBC) will also have temperature capability up to 2700 F and allow for reduced fuel burn. The CMC mixer nozzle will offer reduced weight and improved mixing efficiency to provide reduced fuel burn. The main objectives are to evaluate the manufacturability of the complex-shaped components and to evaluate their performance under simulated engine operating conditions. Progress in CMC component fabrication, evaluation, and testing is presented in which the goal is to advance from the proof of concept validation (TRL 3) to a system/subsystem or prototype demonstration in a relevant environment (TRL 6).

SNCR De-NOx within a moderate temperature range using urea-spiked hydrazine hydrate as reductant.

PubMed

Chen, H; Chen, D Z; Fan, S; Hong, L; Wang, D

2016-10-01

In this research, urea-spiked hydrazine hydrate solutions are used as reductants for the Selective Non-Catalytic Reduction (SNCR) De-NOx process below 650 °C. The urea concentration in the urea/hydrazine hydrate solutions is chosen through experimental and theoretical studies. To determine the mechanism of the De-NOx process, thermogravimetric analysis (TGA) of the urea/hydrazine hydrate solutions and their thermal decomposition in air and nitrogen atmospheres were studied to understand their decomposition behaviours and redox characteristics. Then a plug flow reactor (PFR) model was adopted to simulate the De-NOx processes in a pilot scale tubular reactor, and the calculated De-NOx efficiency vs. temperature profiles were compared with experimental results to support the mechanism and choose the proper reductant and its reaction temperature. Both the experimental and calculated results show that when the urea is spiked into hydrazine hydrate solution to make the urea-N content approximately 16.7%-25% of the total N content in the solution, better De-NOx efficiencies can be obtained in the temperature range of 550-650 °C, under which NH3 is inactive in reducing NOx. And it is also proved that for these urea-spiked hydrazine hydrate solutions, the hydrazine decomposition through the pathway N2H4 + M = N2H3 + H + M is enhanced to provide radical H, which is active to reduce NO. Finally, the reaction routes for SNCR De-NOx process based on urea-spiked hydrazine hydrate at the proper temperature are proposed. Copyright © 2016 Elsevier Ltd. All rights reserved.

DEVELOPMENT AND DEMONSTRATION OF NOVEL LOW-NOx BURNERS IN THE STEEL INDUSTRY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cygan, David

Gas Technology Institute (GTI), together with Hamworthy Peabody Combustion Incorporated (formerly Peabody Engineering Corporation), the University of Utah, and Far West Electrochemical have developed and demonstrated an innovative combustion system suitable for natural gas and coke-oven gas firing within the steel industry. The combustion system is a simple, low-cost, energy-efficient burner that can reduce NOx by more than 75%. The U.S. steel industry needs to address NOx control at its steelmaking facilities. A significant part of NOx emissions comes from gas-fired boilers. In steel plants, byproduct gases – blast furnace gas (BFG) and coke-oven gas (COG) – are widely usedmore » together with natural gas to fire furnaces and boilers. In steel plants, natural gas can be fired together with BFG and COG, but, typically, the addition of natural gas raises NOx emissions, which can already be high because of residual fuel-bound nitrogen in COG. The Project Team has applied its expertise in low-NOx burners to lower NOx levels for these applications by combining advanced burner geometry and combustion staging with control strategies tailored to mixtures of natural gas and byproduct fuel gases. These methods reduce all varieties of NOx – thermal NOx produced by high flame temperatures, prompt NOx produced by complex chain reactions involving radical hydrocarbon species and NOx from fuel-bound nitrogen compounds such as ammonia found in COG. The Project Team has expanded GTI’s highly successful low-NOx forced internal recirculation (FIR) burner, previously developed for natural gas-fired boilers, into facilities that utilize BFG and COG. For natural gas firing, these burners have been shown to reduce NOx emissions from typical uncontrolled levels of 80-100 vppm to single-digit levels (9 vppm). This is done without the energy efficiency penalties incurred by alternative NOx control methods, such as external flue gas recirculation (FGR), water injection, and selective non-catalytic reduction. The FIR burner was previously demonstrated on firetube and watertube boilers, and these units are still operating at several industrial and commercial boiler sites in sizes ranging from 2.5 to 60 million Btu/h. This report covers the development of an innovative combustion system suitable for natural gas or coke-oven gas firing within the steel industry. The prototype FIR burner was evaluated on a 20 million Btu/h watertube boiler. Acceptable burner performance was obtained when firing natural gas and simulated coke-oven gas doped with ammonia. The laboratory data reveals a direct relationship between NOx formation and the ammonia concentration in the fuel. In addition, NOx formation increases as the primary stoichiometric ratio (PSR) increases. Representative ammonia concentrations, as documented in the steel industry, ranged from 200 to 500 vppm. When the laboratory burner/boiler was operated with 500 vppm ammonia in the fuel, NOx emissions ranged from 50 to 75 vppm. This, conservatively, is 75% less than state-of-the-art burner performance. When the burner is operated with 200 vppm ammonia in the fuel, the corresponding NOx emissions would range from 30 to 45 vppm, 84% less than present burner technology. During field evaluation on a 174 million Btu/h industrial prototype burner both natural gas and actual COG from on-site generation were tested. Despite the elevated hydrogen cyanide and ammonia content in the COG throughout the test program, the FIR burner showed an improvement over baseline emissions. At full load; 167 million Btu/h, NOx emissions were relatively low at 169 vppm. This represents a 30% reduction compared to baseline emissions not accounting for the higher hydrogen cyanide content in the COG. CO emissions remained below 20 vppm and were stable across the firing range. This represents a 68% reduction compared to baseline CO emissions. When firing natural gas, emissions were stable as firing rate increased over the range. At low fire; 45 million Btu/h, NOx emissions where 33 vppm and increased at full load; 144 million Btu/h, to 49 vppm. CO emissions fluctuated with the oxygen content and remained below 135 vppm during all tests. The boiler’s maximum output was not achieved due to a limitation dictated by the host site natural gas supply. The FIR burner benefits the public by simultaneously addressing the problems of air pollution and energy conservation through a low-NOx combustion technology that does not increase energy consumption. Continuing activities include the negotiation of a license with Hamworthy Peabody Combustion, Incorporated (Hamworthy Peabody) to commercialize the FIR burner for steel industry applications. Hamworthy Peabody is one of the largest U.S. manufacturers of combustion equipment for boilers in the Steel Industry, and has stated their intention to commercialize the FIR burner.« less

Idle emissions from heavy-duty diesel vehicles: review and recent data.

PubMed

Khan, A B M S; Clark, Nigel N; Thompson, Gregory J; Wayne, W Scott; Gautam, Mridul; Lyons, Donald W; Hawelti, Daniel

2006-10-01

Heavy-duty diesel vehicle idling consumes fuel and reduces atmospheric quality, but its restriction cannot simply be proscribed, because cab heat or air-conditioning provides essential driver comfort. A comprehensive tailpipe emissions database to describe idling impacts is not yet available. This paper presents a substantial data set that incorporates results from the West Virginia University transient engine test cell, the E-55/59 Study and the Gasoline/Diesel PM Split Study. It covered 75 heavy-duty diesel engines and trucks, which were divided into two groups: vehicles with mechanical fuel injection (MFI) and vehicles with electronic fuel injection (EFI). Idle emissions of CO, hydrocarbon (HC), oxides of nitrogen (NOx), particulate matter (PM), and carbon dioxide (CO2) have been reported. Idle CO2 emissions allowed the projection of fuel consumption during idling. Test-to-test variations were observed for repeat idle tests on the same vehicle because of measurement variation, accessory loads, and ambient conditions. Vehicles fitted with EFI, on average, emitted approximately 20 g/hr of CO, 6 g/hr of HC, 86 g/hr of NOx, 1 g/hr of PM, and 4636 g/hr of CO2 during idle. MFI equipped vehicles emitted approximately 35 g/hr of CO, 23 g/hr of HC, 48 g/hr of NOx, 4 g/hr of PM, and 4484 g/hr of CO2, on average, during idle. Vehicles with EFI emitted less idle CO, HC, and PM, which could be attributed to the efficient combustion and superior fuel atomization in EFI systems. Idle NOx, however, increased with EFI, which corresponds with the advancing of timing to improve idle combustion. Fuel injection management did not have any effect on CO2 and, hence, fuel consumption. Use of air conditioning without increasing engine speed increased idle CO2, NOx, PM, HC, and fuel consumption by 25% on average. When the engine speed was elevated from 600 to 1100 revolutions per minute, CO2 and NOx emissions and fuel consumption increased by >150%, whereas PM and HC emissions increased by approximately 100% and 70%, respectively. Six Detroit Diesel Corp. (DDC) Series 60 engines in engine test cell were found to emit less CO, NOx, and PM emissions and consumed fuel at only 75% of the level found in the chassis dynamometer data. This is because fan and compressor loads were absent in the engine test cell.

Research on the influence of ozone dissolved in the fuel-water emulsion on the parameters of the CI engine

NASA Astrophysics Data System (ADS)

Wojs, M. K.; Orliński, P.; Kamela, W.; Kruczyński, P.

2016-09-01

The article presents the results of empirical research on the impact of ozone dissolved in fuel-water emulsion on combustion process and concentration of toxic substances in CI engine. The effect of ozone presence in the emulsion and its influence on main engine characteristics (power, torque, fuel consumption) and selected parameters that characterize combustion process (levels of pressures and temperatures in combustion chamber, period of combustion delay, heat release rate, fuel burnt rate) is shown. The change in concentration of toxic components in exhausts gases when engine is fueled with ozonized emulsion was also identified. The empirical research and their analysis showed significant differences in the combustion process when fuel-water emulsion containing ozone was used. These differences include: increased power and efficiency of the engine that are accompanied by reduction in time of combustion delay and beneficial effects of ozone on HC, PM, CO and NOX emissions.

Trend and future of diesel engine: Development of high efficiency and low emission low temperature combustion diesel engine

NASA Astrophysics Data System (ADS)

Ho, R. J.; Yusoff, M. Z.; Palanisamy, K.

2013-06-01

Stringent emission policy has put automotive research & development on developing high efficiency and low pollutant power train. Conventional direct injection diesel engine with diffused flame has reached its limitation and has driven R&D to explore other field of combustion. Low temperature combustion (LTC) and homogeneous charge combustion ignition has been proven to be effective methods in decreasing combustion pollutant emission. Nitrogen Oxide (NOx) and Particulate Matter (PM) formation from combustion can be greatly suppressed. A review on each of method is covered to identify the condition and processes that result in these reductions. The critical parameters that allow such combustion to take place will be highlighted and serves as emphasis to the direction of developing future diesel engine system. This paper is written to explore potential of present numerical and experimental methods in optimizing diesel engine design through adoption of the new combustion technology.

Suresh K. AggarwalQuantified Analysis of a Production Diesel Injector Using X-Ray Radiography and Engine Diagnostics

NASA Astrophysics Data System (ADS)

Ramirez, Anita I.

The work presented in this thesis pursues further the understanding of fuel spray, combustion, performance, and emissions in an internal combustion engine. Various experimental techniques including x-ray radiography, injection rate measurement, and in-cylinder endoscopy are employed in this work to characterize the effects of various upstream conditions such as injection rate profile and fuel physical properties. A single non-evaporating spray from a 6-hole full-production Hydraulically Actuated Electronically Controlled Unit Injector (HEUI) nozzle is studied under engine-like ambient densities with x-ray radiography at the Advanced Photon Source (APS) of Argonne National Laboratory (ANL). Two different injection pressures were investigated and parameters such as fuel mass distribution, spray penetration, cone angle, and spray velocity were obtained. The data acquired with x-ray radiography is used for the development and validation of improved Computational Fluid Dynamic (CFD) models. Rate of injection is studied using the same HEUI in a single cylinder Caterpillar test engine. The injection rate profile is altered to have three levels of initial injection pressure rise. Combustion behavior, engine performance, and emissions information was acquired for three rate profile variations. It is found that NOx emission reduction is achieved when the SOI timing is constant at the penalty of lower power generated in the cycle. However, if CA50 is aligned amongst the three profiles, the NOx emissions and power are constant with a slight penalty in CO emissions. The influence of physical and chemical parameters of fuel is examined in a study of the heavy alcohol, phytol (C20H40O), in internal combustion engine application. Phytol is blended with diesel in 5%, 10%, and 20% by volume. Combustion behavior is similar between pure diesel and the phytol/diesel blends with small differences noted in peak cylinder pressure, ignition delay, and heat release rate in the premix burn phase. Diesel/phytol blends yield marginally lower power values. In-cylinder soot radiation images show combustion instability at the start of the event for the 20% phytol/diesel blend. Overall, NOx emissions are comparable across the different fuels used and no discernible trend is found in CO emissions.

Energy efficient engine: Flight propulsion system preliminary analysis and design

NASA Technical Reports Server (NTRS)

Johnston, R. P.; Beitler, R. S.; Bobinger, R. O.; Broman, C. L.; Gravitt, R. D.; Heineke, H.; Holloway, P. R.; Klem, J. S.; Nash, D. O.; Ortiz, P.

1980-01-01

The characteristics of an advanced flight propulsion system (FPS), suitable for introduction in the late 1980's to early 1990's, was more fully defined. It was determined that all goals for efficiency, environmental considerations, and economics could be met or exceeded with the possible exception of NOx emission. In evaluating the FPS, all aspects were considered including component design, performance, weight, initial cost, maintenance cost, engine system integration (including nacelle), and aircraft integration considerations. The current FPS installed specific fuel consumption was reduced 14.2% from that of the CF6-50C reference engine. When integrated into an advanced, subsonic, study transport, the FPS produced a fuel burn savings of 15 to 23% and a direct operating cost reduction of 5 to 12% depending on the mission and study aircraft characteristics relative to the reference engine.

A New Paradigm in Modeling and Simulations of Complex Oxidation Chemistry Using a Statistical Approach

DTIC Science & Technology

2009-03-31

8. This range encompasses diesel , HCCI and gas turbine engines , including cold ignition; and NOx , CO and soot pollutant formation in the lean and...equivalence ratios from 0.125 to 8. This range encompasses diesel , HCCI and gas turbine engines , including cold ignition; and NOx , CO and soot pollutant...California Institute of Technology Mechanical Engineering Department Pasadena CA 91125 i Abstract This report describes a study

40 CFR 76.5 - NOX emission limitations for Group 1 boilers.

Code of Federal Regulations, 2014 CFR

2014-07-01

... PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.5 NOX emission limitations..., the date on which the unit is required to meet Acid Rain emission reduction requirements for SO2, the... subject to section 404(d) of the Act, the date the unit is required to meet Acid Rain emissions reduction...

2001 NASA Seal/secondary Air System Workshop, Volume 1. Volume 1

NASA Technical Reports Server (NTRS)

Steinetz, Bruce M. (Editor); Hendricks, Robert C. (Editor)

2002-01-01

The 2001 NASA Seal/Secondary Air System Workshop covered the following topics: (i) overview of NASA's Vision for 21st Century Aircraft; (ii) overview of NASA-sponsored Ultra-Efficient Engine Technology (UEET); (iii) reviews of sealing concepts, test results, experimental facilities, and numerical predictions; and (iv) reviews of material development programs relevant to advanced seals development. The NASA UEET overview illustrates for the reader the importance of advanced technologies, including seals, in meeting future turbine engine system efficiency and emission goals. The NASA UEET program goals include an 8-to 15-percent reduction in fuel burn, a 15-percent reduction in CO2, a 70-percent reduction in NOx, CO, and unburned hydrocarbons, and a 30-dB noise reduction relative to program baselines. The workshop also covered several programs NASA is funding to investigate advanced reusable space vehicle technologies (X-38) and advanced space ram/scramjet propulsion systems. Seal challenges posed by these advanced systems include high-temperature operation, resiliency at the operating temperature to accommodate sidewall flexing, and durability to last many missions.

Final Report of a CRADA Between Pacific Northwest National Laboratory and the Ford Motor Company (CRADA No. PNNL/265): “Deactivation Mechanisms of Base Metal/Zeolite Urea Selective Catalytic Reduction Materials, and Development of Zeolite-Based Hydrocarbon Adsorber Materials”

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Feng; Kwak, Ja Hun; Lee, Jong H.

2013-02-14

Reducing NOx emissions and particulate matter (PM) are primary concerns for diesel vehicles required to meet current LEV II and future LEV III emission standards which require 90+% NOx conversion. Currently, urea SCR as the NOx reductant and a Catalyzed Diesel Particulate Filter (CDPF) are being used for emission control system components by Ford Motor Company for 2010 and beyond diesel vehicles. Because the use of this technology for vehicle applications is new, the relative lack of experience makes it especially challenging to satisfy durability requirements. Of particular concern is being able to realistically simulate actual field aging of themore » catalyst systems under laboratory conditions. This is necessary both as a rapid assessment tool for verifying improved performance and certifiability of new catalyst formulations, and to develop a good understanding of deactivation mechanisms that can be used to develop improved catalyst materials. In addition to NOx and PM, the hydrocarbon (HC) emission standards are expected to become much more stringent during the next few years. Meanwhile, the engine-out HC emissions are expected to increase and/or be more difficult to remove. Since HC can be removed only when the catalyst becomes warm enough for its oxidation, three-way catalyst (TWC) and diesel oxidation catalyst (DOC) formulations often contain proprietary zeolite materials to hold the HC produced during the cold start period until the catalyst reaches its operating temperature (e.g., >200°C). Unfortunately, much of trapped HC tends to be released before the catalyst reaches the operating temperature. Among materials effective for trapping HC during the catalyst warm-up period, siliceous zeolites are commonly used because of their high surface area and high stability under typical operating conditions. However, there has been little research on the physical properties of these materials related to the adsorption and release of various hydrocarbon species found in the engine exhaust. For these reasons, automakers and engine manufacturers have difficulty improving their catalytic converters for meeting the stringent HC emission standards. In this collaborative program, scientists and engineers in the Institute for Integrated Catalysis at Pacific Northwest National Laboratory and at Ford Motor Company have investigated laboratory- and engine-aged SCR catalysts, containing mainly base metal zeolites. These studies are leading to a better understanding of various aging factors that impact the long-term performance of SCR catalysts and improve the correlation between laboratory and engine aging, saving experimental time and cost. We have also studied materials effective for the temporary storage of HC species during the cold-start period. In particular, we have examined the adsorption and desorption of various HC species produced during the combustion with different fuels (e.g., gasoline, E85, diesel) over potential HC adsorber materials, and measured the kinetic parameters to update Ford’s HC adsorption model. Since this CRADA has now been completed, in this final report we will provide brief summaries of most of the work carried out on this CRADA over the last several years.« less

Measurements of NOx emissions and in-service duty cycle from a towboat operating on the inland river system.

PubMed

Corbett, J J; Robinson, A L

2001-04-01

This paper describes measurements of NOx emissions from one engine on a commercial towboat operating on the Upper Ohio River system around the Port of Pittsburgh. Continuous measurements were made over a one-week period to characterize emissions during normal operations. The average NOx emission factor is 70 +/- 4.2 kg of NOx per t of fuel, similar to that of larger marine engines. A vessel-specific duty cycle is derived to characterize the towboat's operations; more than 50% of the time the vessel engines are at idle. Although recently promulgated EPA regulations apply only to new marine engines, these data provide insight into inland-river operations, which can be used to evaluate these regulations within the inland river context. This vessel operates as a courier service, scheduling pickups and deliveries of single- or multiple-barge loads per customers' requests; as many as 30% of the 277 towboats in the Pittsburgh region operate in this fashion. The EPA-prescribed ISO E3 duty cycle does not accurately describe inland-river operations of this towboat: its application overestimates actual NOx emissions by 14%. Only 41% of this vessel's operations fall within the Not-To-Exceed Zone defined by the EPA regulations, which limits the effectiveness of this component of the regulations to limit emissions from vessels that operate in a similar fashion.

Nitrogen Stable Isotope Composition of Various Fossil-fuel Combustion Nitrogen Oxide Sources

NASA Astrophysics Data System (ADS)

Walters, W.; Michalski, G. M.; Fang, H.

2015-12-01

Nitrogen oxides (NOx = NO + NO2) are important trace gases that impact atmospheric chemistry, air quality, and climate. In order to help constrain NOx source contributions, the nitrogen (N) stable isotope composition of NOx (δ15N-NOx) may be a useful indicator for NOx source partitioning. However, despite anthropogenic emissions being the most prevalent source of NOx, there is still large uncertainty in the δ15N-NOx values for anthropogenic sources. To this end, this study provides a detailed analysis of several fossil-fuel combustion NOx sources and their δ15N-NOx values. To accomplish this, exhaust or flue samples from several fossil-fuel combustion sources were sampled and analyzed for their δ15N-NOx that included airplanes, gasoline-powered vehicles not equipped with a catalytic converter, gasoline-powered lawn tools and utility vehicles, diesel-electric buses, diesel semi-trucks, and natural gas-burning home furnace and power plant. A relatively large range of δ15N-NOx values were measured from -28.1 to 0.3‰ for individual exhaust/flue samples with cold started diesel-electric buses contributing on average the lowest δ15N-NOx values at -20.9‰, and warm-started diesel-electric buses contributing on average the highest values of -1.7‰. The NOx sources analyzed in this study primarily originated from the "thermal production" of NOx and generally emitted negative δ15N-NOx values, likely due to the kinetic isotope effect associated with its production. It was found that there is a negative correlation between NOx concentrations and δ15N-NOx for fossil-fuel combustion sources equipped with catalytic NOx reduction technology, suggesting that the catalytic reduction of NOx may have an influence on δ15N-NOx values. Based on the δ15N-NOx values reported in this study and in previous studies, a δ15N-NOx regional and seasonal isoscape was constructed for the contiguous United States. The constructed isoscape demonstrates the seasonal importance of various NOx sources to particular regions and will be helpful in evaluating the N isotopes in nitrate deposition studies.

Real-time gaseous, PM and ultrafine particle emissions from a modern marine engine operating on biodiesel.

PubMed

Jayaram, Varalakshmi; Agrawal, Harshit; Welch, William A; Miller, J Wayne; Cocker, David R

2011-03-15

Emissions from harbor-craft significantly affect air quality in populated regions near ports and inland waterways. This research measured regulated and unregulated emissions from an in-use EPA Tier 2 marine propulsion engine on a ferry operating in a bay following standard methods. A special effort was made to monitor continuously both the total Particulate Mass (PM) mass emissions and the real-time Particle Size Distribution (PSD). The engine was operated following the loads in ISO 8178-4 E3 cycle for comparison with the certification standards and across biodiesel blends. Real-time measurements were also made during a typical cruise in the bay. Results showed the in-use nitrogen oxide (NOx) and PM(2.5) emission factors were within the not to exceed standard for Tier 2 marine engines. Comparing across fuels we observed the following: a) no statistically significant change in NO(x) emissions with biodiesel blends (B20, B50); b) ∼ 16% and ∼ 25% reduction of PM(2.5) mass emissions with B20 and B50 respectively; c) a larger organic carbon (OC) to elemental carbon (EC) ratio and organic mass (OM) to OC ratio with B50 compared to B20 and B0; d) a significant number of ultrafine nuclei and a smaller mass mean diameter with increasing blend-levels of biodiesel. The real-time monitoring of gaseous and particulate emissions during a typical cruise in the San Francisco Bay (in-use cycle) revealed important effects of ocean/bay currents on emissions: NO(x) and CO(2) increased 3-fold; PM(2.5) mass increased 6-fold; and ultrafine particles disappeared due to the effect of bay currents. This finding has implications on the use of certification values instead of actual in-use emission values when developing inventories. Emission factors for some volatile organic compounds (VOCs), carbonyls, and poly aromatic hydrocarbons (PAHs) are reported as supplemental data.

Gaseous emissions from a heavy-duty engine equipped with SCR aftertreatment system and fuelled with diesel and biodiesel: assessment of pollutant dispersion and health risk.

PubMed

Tadano, Yara S; Borillo, Guilherme C; Godoi, Ana Flávia L; Cichon, Amanda; Silva, Thiago O B; Valebona, Fábio B; Errera, Marcelo R; Penteado Neto, Renato A; Rempel, Dennis; Martin, Lucas; Yamamoto, Carlos I; Godoi, Ricardo H M

2014-12-01

The changes in the composition of fuels in combination with selective catalytic reduction (SCR) emission control systems bring new insights into the emission of gaseous and particulate pollutants. The major goal of our study was to quantify NOx, NO, NO2, NH3 and N2O emissions from a four-cylinder diesel engine operated with diesel and a blend of 20% soybean biodiesel. Exhaust fume samples were collected from bench dynamometer tests using a heavy-duty diesel engine equipped with SCR. The target gases were quantified by means of Fourier transform infrared spectrometry (FTIR). The use of biodiesel blend presented lower concentrations in the exhaust fumes than using ultra-low sulfur diesel. NOx and NO concentrations were 68% to 93% lower in all experiments using SCR, when compared to no exhaust aftertreatment. All fuels increased NH3 and N2O emission due to SCR, a precursor secondary aerosol, and major greenhouse gas, respectively. An AERMOD dispersion model analysis was performed on each compound results for the City of Curitiba, assumed to have a bus fleet equipped with diesel engines and SCR system, in winter and summer seasons. The health risks of the target gases were assessed using the Risk Assessment Information System For 1-h exposure of NH3, considering the use of low sulfur diesel in buses equipped with SCR, the results indicated low risk to develop a chronic non-cancer disease. The NOx and NO emissions were the lowest when SCR was used; however, it yielded the highest NH3 concentration. The current results have paramount importance, mainly for countries that have not yet adopted the Euro V emission standards like China, India, Australia, or Russia, as well as those already adopting it. These findings are equally important for government agencies to alert the need of improvements in aftertreatment technologies to reduce pollutants emissions. Copyright © 2014. Published by Elsevier B.V.

Investigation of engine performance and emissions of a diesel engine with a blend of marine gas oil and synthetic diesel fuel.

PubMed

Nabi, Md Nurun; Hustad, Johan Einar

2012-01-01

This paper investigates diesel engine performance and exhaust emissions with marine gas oil (MGO) and a blend of MGO and synthetic diesel fuel. Ten per cent by volume of Fischer-Tropsch (FT), a synthetic diesel fuel, was added to MGO to investigate its influence on the diesel engine performance and emissions. The blended fuel was termed as FT10 fuel, while the neat (100 vol%) MGO was termed as MGO fuel. The experiments were conducted with a fourstroke, six-cylinder, turbocharged, direct injection, Scania DC 1102 diesel engine. It is interesting to note that all emissions including smoke (filter smoke number), total particulate matter (TPM), carbon monoxide (CO), total unburned hydrocarbon (THC), oxides of nitrogen (NOx) and engine noise were reduced with FT10 fuel compared with the MGO fuel. Diesel fine particle number and mass emissions were measured with an electrical low pressure impactor. Like other exhaust emissions, significant reductions in fine particles and mass emissions were observed with the FT10 fuel. The reduction was due to absence of sulphur and aromatic compounds in the FT fuel. In-cylinder gas pressure and engine thermal efficiency were identical for both FT10 and MGO fuels.

40 CFR 94.304 - Compliance requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... specified in this part, except that the applicable FEL replaces the applicable THC+NOX and PM emission... life shall be unlimited. (m) Upper limits. The FELs for THC+NOX and PM for new engines certified for...—Category 1 Upper Limits for Tier 2 Family Emission Limits Subcategory liters/cylinder Model year 1 THC+NOX...

40 CFR 94.304 - Compliance requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... specified in this part, except that the applicable FEL replaces the applicable THC+NOX and PM emission... life shall be unlimited. (m) Upper limits. The FELs for THC+NOX and PM for new engines certified for...—Category 1 Upper Limits for Tier 2 Family Emission Limits Subcategory liters/cylinder Model year 1 THC+NOX...

40 CFR 94.304 - Compliance requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... specified in this part, except that the applicable FEL replaces the applicable THC+NOX and PM emission... life shall be unlimited. (m) Upper limits. The FELs for THC+NOX and PM for new engines certified for...—Category 1 Upper Limits for Tier 2 Family Emission Limits Subcategory liters/cylinder Model year 1 THC+NOX...

40 CFR 94.304 - Compliance requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... specified in this part, except that the applicable FEL replaces the applicable THC+NOX and PM emission... life shall be unlimited. (m) Upper limits. The FELs for THC+NOX and PM for new engines certified for...—Category 1 Upper Limits for Tier 2 Family Emission Limits Subcategory liters/cylinder Model year 1 THC+NOX...

40 CFR 94.304 - Compliance requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... specified in this part, except that the applicable FEL replaces the applicable THC+NOX and PM emission... life shall be unlimited. (m) Upper limits. The FELs for THC+NOX and PM for new engines certified for...—Category 1 Upper Limits for Tier 2 Family Emission Limits Subcategory liters/cylinder Model year 1 THC+NOX...

Evaluation of NOx emissions of a retrofitted Euro 5 passenger car for the Horizon prize "Engine retrofit".

PubMed

Giechaskiel, Barouch; Suarez-Bertoa, Ricardo; Lähde, Tero; Clairotte, Michael; Carriero, Massimo; Bonnel, Pierre; Maggiore, Maurizio

2018-06-13

The Horizon 2020 prize for the "Engine Retrofit for Clean Air" aims at reducing the pollution in cities by spurring the development of retrofit technology for diesel engines. A Euro 5 passenger car was retrofitted with an under-floor SCR (Selective Catalytic Reduction) for NO x catalyst in combination with a solid ammonia based dosing system as the NO x reductant. The vehicle was tested both on the road and on the chassis dynamometer under various test cycles and ambient temperatures. The NO x emissions were reduced by 350-1100 mg/km (60-85%) in the laboratory depending on the test cycle and engine conditions (cold or hot start), except at type approval conditions. The reduction for cold start urban cycles was < 75 mg/km (< 15%). The on road and laboratory tests were inline. In some high speed conditions significant increase of ammonia (NH 3 ) and nitrous oxide (N 2 O) were measured. No effect was seen on other pollutants (hydrocarbons, carbon monoxide and particles). The results of the present study show that retrofitting high emitting vehicles can significantly reduce vehicle NO x emissions and ultimately pollution in cities. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

In-Plume Emission Test Stand 2: emission factors for 10- to 100-kW U.S. military generators.

PubMed

Zhu, Dongzi; Nussbaum, Nicholas J; Kuhns, Hampden D; Chang, M-C Oliver; Sodeman, David; Uppapalli, Sebastian; Moosmüller, Hans; Chow, Judith C; Watson, John G

2009-12-01

Although emissions of air pollutants from some military tactical equipment are not subject to the emissions standards, local communities near military bases must conform to the National Ambient Air Quality Standards. Military diesel generators are widely used in training. A portable in-plume system was used to measure fuel-based emission factors (EFs) for particulate matter (PM), carbon monoxide (CO), nitrogen oxides (NOx), and hydrocarbons (HCs) for 30-, 60-, and 100-kW generators at five load levels and for cold starts. It was found that EFs depend on multiple parameters including engine size, engine load, unit age, and total running hours. The average CO EF of generators tested was 5% lower, and the average NOx EF was 63% lower than AP-42 estimates; average PM EF was 80% less than the AP-42 estimates. A 2002 model-year 60-kW engine produced 25% less PM than a 1995 engine of the same family with similar running hours. CO EFs decrease with increasing engine load, NOx EFs increase up to mid-loads and decrease slightly at high loads, PM EFs increase with loads for 30- and 60-kW engines. CO and PM have higher EFs and NOx has a lower EF during cold starts than during hot-stabilized operation. PM chemical source profiles were also examined.

Method for reduction of the NOX emissions in marine auxiliary diesel engine using the fuel mixtures containing biodiesel using HCCI combustion.

PubMed

Puškár, Michal; Kopas, Melichar; Puškár, Dušan; Lumnitzer, Ján; Faltinová, Eva

2018-02-01

The marine auxiliary diesel engines installed in the large transoceanic ships are used in order to generate the electricity but at the same time these engines are able to produce a significant amount of the harmful exhaust gas emissions. Therefore the International Maritime Organisation (IMO) concluded an agreement, which has to control generating of gaseous emissions in maritime transport. From this reason started to be used some of the alternative fuels in this branch. There was performed a study, which investigated emissions of the auxiliary marine diesel engine during application of the experimental fuels. The different testing fuels were created using the ratios 0%, 50%, 80% and 100% between the biodiesel and the ULSDF (Ultra Low Sulphur Diesel Fuel). The experimental measurements were performed at the different engine loading levels and various engine speeds in order to investigate an influence of the mixed fuels on the engine operational characteristics. Copyright © 2017 Elsevier Ltd. All rights reserved.

Designing, installing and operating low NOx combustion systems in power plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lazzeri, L.; Santis, R. de

1997-09-01

Ansaldo Energia, in strict cooperation with the Italian Electricity Board (ENEL), has developed and implemented innovative technologies for in furnace NOx control which have been applied, both in italy and abroad, on over 20,000 MWe boilers of every kind (Tangentially Fired, Front Fired, Opposite Fired) and for different fuels like oil, gas, coal and ORIMULSION{reg_sign}. Taking advantage of innovative low NOx burners and of optimized air and fuel staging techniques NOx reductions up to 85% have been obtained with no significant impact on boiler efficiency. The paper describes: characteristics and industrial application of TEA{reg_sign} oil/gas LNB which is now capablemore » of attaining NOx reductions up to 60% in respect to original circular burners; development and industrial applications of the TEA C{reg_sign} (oil/coal) LNB, capable of attaining NOx reductions up to 50% with contemporary control of unburned carbon levels (typical values less than 300 ppm NOx corrected to 6% O{sub 2} and less than 7% UBC); application of reburning oil over oil and gas over oil for both tangential and front-opposite fired boilers rated up 660 MWe; and information on the CEE THERMIE projects of gas over coal reburning in a 600 MWe Scottish Power boiler and oil over coal and coal over coal reburning in the ENEL plant of Vado Ligure unit 4, rated 320 MWe.« less

Compliance of Royal Naval ships with nitrogen oxide emissions legislation.

PubMed

Blatcher, D J; Eames, I

2013-09-15

Nitrogen oxide (NOx) emissions from marine diesel engines pose a hazard to human health and the environment. From 2021, demanding emissions limits are expected to be applied to sea areas that the Royal Navy (RN) accesses. We analyze how these future constraints affect the choice of NOx abatement systems for RN ships, which are subject to more design constraints than civilian ships. A weighted matrix approach is used to facilitate a quantitative assessment. For most warships to be built soon after 2021 Lean Nitrogen Traps (LNT) in conjunction with Exhaust Gas Recirculation (EGR) represents a relatively achievable option with fewer drawbacks than other system types. Urea-selective catalytic reduction is likely to be most appropriate for ships that are built to civilian standards. The future technologies that are at an early stage of development are discussed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Two-stage combustion for reducing pollutant emissions from gas turbine combustors

NASA Technical Reports Server (NTRS)

Clayton, R. M.; Lewis, D. H.

1981-01-01

Combustion and emission results are presented for a premix combustor fueled with admixtures of JP5 with neat H2 and of JP5 with simulated partial-oxidation product gas. The combustor was operated with inlet-air state conditions typical of cruise power for high performance aviation engines. Ultralow NOx, CO and HC emissions and extended lean burning limits were achieved simultaneously. Laboratory scale studies of the non-catalyzed rich-burning characteristics of several paraffin-series hydrocarbon fuels and of JP5 showed sooting limits at equivalence ratios of about 2.0 and that in order to achieve very rich sootless burning it is necessary to premix the reactants thoroughly and to use high levels of air preheat. The application of two-stage combustion for the reduction of fuel NOx was reviewed. An experimental combustor designed and constructed for two-stage combustion experiments is described.

Measurements of nitrous acid in commercial aircraft exhaust at the Alternative Aviation Fuel Experiment.

PubMed

Lee, Ben H; Santoni, Gregory W; Wood, Ezra C; Herndon, Scott C; Miake-Lye, Richard C; Zahniser, Mark S; Wofsy, Steven C; Munger, J William

2011-09-15

The Alternative Aviation Fuel Experiment (AAFEX), conducted in January of 2009 in Palmdale, California, quantified aerosol and gaseous emissions from a DC-8 aircraft equipped with CFM56-2C1 engines using both traditional and synthetic fuels. This study examines the emissions of nitrous acid (HONO) and nitrogen oxides (NO(x) = NO + NO(2)) measured 145 m behind the grounded aircraft. The fuel-based emission index (EI) for HONO increases approximately 6-fold from idle to takeoff conditions but plateaus between 65 and 100% of maximum rated engine thrust, while the EI for NO(x) increases continuously. At high engine power, NO(x) EI is greater when combusting traditional (JP-8) rather than Fischer-Tropsch fuels, while HONO exhibits the opposite trend. Additionally, hydrogen peroxide (H(2)O(2)) was identified in exhaust plumes emitted only during engine idle. Chemical reactions responsible for emissions and comparison to previous measurement studies are discussed.

Experimental investigation on emission reduction in neem oil biodiesel using selective catalytic reduction and catalytic converter techniques.

PubMed

Viswanathan, Karthickeyan

2018-05-01

In the present study, non-edible seed oil namely raw neem oil was converted into biodiesel using transesterification process. In the experimentation, two biodiesel blends were prepared namely B25 (25% neem oil methyl ester with 75% of diesel) and B50 (50% neem oil methyl ester with 50% diesel). Urea-based selective catalytic reduction (SCR) technique with catalytic converter (CC) was fixed in the exhaust tail pipe of the engine for the reduction of engine exhaust emissions. Initially, the engine was operated with diesel as a working fluid and followed by refilling of biodiesel blends B25 and B50 to obtain the baseline readings without SCR and CC. Then, the same procedure was repeated with SCR and CC technique for emission reduction measurement in diesel, B25 and B50 sample. The experimental results revealed that the B25 blend showed higher break thermal efficiency (BTE) and exhaust gas temperature (EGT) with lower break-specific fuel consumption (BSFC) than B50 blend at all loads. On comparing with biodiesel blends, diesel experiences increased BTE of 31.9% with reduced BSFC of 0.29 kg/kWh at full load. A notable emission reduction was noticed for all test fuels in SCR and CC setup. At full load, B25 showed lower carbon monoxide (CO) of 0.09% volume, hydrocarbon (HC) of 24 ppm, and smoke of 14 HSU and oxides of nitrogen (NOx) of 735 ppm than diesel and B50 in SCR and CC setup. On the whole, the engine with SCR and CC setup showed better performance and emission characteristics than standard engine operation.

Advanced Low Emissions Subsonic Combustor Study

NASA Technical Reports Server (NTRS)

Smith, Reid

1998-01-01

Recent advances in commercial and military aircraft gas turbines have yielded significant improvements in fuel efficiency and thrust-to-weight ratio, due in large part to increased combustor operating pressures and temperatures. However, the higher operating conditions have increased the emission of oxides of nitrogen (NOx), which is a pollutant with adverse impact on the atmosphere and environment. Since commercial and military aircraft are the only important direct source of NOx emissions at high altitudes, there is a growing consensus that considerably more stringent limits on NOx emissions will be required in the future for all aircraft. In fact, the regulatory communities have recently agreed to reduce NOx limits by 20 percent from current requirements effective in 1996. Further reductions at low altitude, together with introduction of limits on NOx at altitude, are virtual certainties. In addition, the U.S. Government recently conducted hearings on the introduction of federal fees on the local emission of pollutants from all sources, including aircraft. While no action was taken regarding aircraft in this instance, the threat of future action clearly remains. In these times of intense and growing international competition, the U.S. le-ad in aerospace can only be maintained through a clear technological dominance that leads to a product line of maximum value to the global airline customer. Development of a very low NOx combustor will be essential to meet the future needs of both the commercial and military transport markets, if additional economic burdens and/or operational restrictions are to be avoided. In this report, Pratt & Whitney (P&W) presents the study results with the following specific objectives: Development of low-emissions combustor technologies for advances engines that will enter into service circa 2005, while producing a goal of 70 percent lower NOx emissions, compared to 1996 regulatory levels. Identification of solution approaches to barriers to the productization and economic viability of the low-emissions technologies. Preparation of these technologies to facilitate an annular rig high-pressure demonstration.

THE ACID RAIN NOX PROGRAM

EPA Science Inventory

Between 350,000 and 400,000 tons of annual NOx emissions have been eliminated as a result of Phase I of the Acid Rain NOx Program. As expected. the utilities have chosen emissions averaging as the primary compliance option. This reflects that, in general, NO x reductions have ...

An optimization model for regional air pollutants mitigation based on the economic structure adjustment and multiple measures: A case study in Urumqi city, China.

PubMed

Sun, Xiaowei; Li, Wei; Xie, Yulei; Huang, Guohe; Dong, Changjuan; Yin, Jianguang

2016-11-01

A model based on economic structure adjustment and pollutants mitigation was proposed and applied in Urumqi. Best-worst case analysis and scenarios analysis were performed in the model to guarantee the parameters accuracy, and to analyze the effect of changes of emission reduction styles. Results indicated that pollutant-mitigations of electric power industry, iron and steel industry, and traffic relied mainly on technological transformation measures, engineering transformation measures and structure emission reduction measures, respectively; Pollutant-mitigations of cement industry relied mainly on structure emission reduction measures and technological transformation measures; Pollutant-mitigations of thermal industry relied mainly on the four mitigation measures. They also indicated that structure emission reduction was a better measure for pollutants mitigation of Urumqi. Iron and steel industry contributed greatly in SO2, NOx and PM (particulate matters) emission reduction and should be given special attention in pollutants emission reduction. In addition, the scales of iron and steel industry should be reduced with the decrease of SO2 mitigation amounts. The scales of traffic and electric power industry should be reduced with the decrease of NOx mitigation amounts, and the scales of cement industry and iron and steel industry should be reduced with the decrease of PM mitigation amounts. The study can provide references of pollutants mitigation schemes to decision-makers for regional economic and environmental development in the 12th Five-Year Plan on National Economic and Social Development of Urumqi. Copyright © 2016 Elsevier Ltd. All rights reserved.

BENCH-SCALE PROCESS EVALUATION OF REBURNING AND SORBENT INJECTION FOR IN-FURNACE NOX/SOX REDUCTION

EPA Science Inventory

The report gives results of combining reburning with the injection of calcium-based sorbents to investigate the potential for combined NOx and SOx reduction. Reburning, applied to pulverized-coal-fired utility boilers, involves injecting a secondary fuel above the main firing zon...

INVESTIGATION OF SELECTIVE CATALYTIC REDUCTION IMPACT ON MERCURY SPECIATION UNDER SIMULATED NOX EMISSION CONTROL CONDITIONS

EPA Science Inventory

Selective catalytic reduction (SCR) technology is being increasingly applied for controlling emissions of nitrogen oxides (NOx) from coal-fired boilers. Some recent field and pilot studies suggest that the operation of SCR could affect the chemical form of mercury in the coal com...

A case study of the relative effects of power plant nitrogen oxides and sulfur dioxide emission reductions on atmospheric nitrogen deposition.

PubMed

Vijayaraghavan, Krish; Seigneur, Christian; Bronson, Rochelle; Chen, Shu-Yun; Karamchandani, Prakash; Walters, Justin T; Jansen, John J; Brandmeyer, Jo Ellen; Knipping, Eladio M

2010-03-01

The contrasting effects of point source nitrogen oxides (NOx) and sulfur dioxide (SO2) air emission reductions on regional atmospheric nitrogen deposition are analyzed for the case study of a coal-fired power plant in the southeastern United States. The effect of potential emission reductions at the plant on nitrogen deposition to Escambia Bay and its watershed on the Florida-Alabama border is simulated using the three-dimensional Eulerian Community Multiscale Air Quality (CMAQ) model. A method to quantify the relative and individual effects of NOx versus SO2 controls on nitrogen deposition using air quality modeling results obtained from the simultaneous application of NOx and SO2 emission controls is presented and discussed using the results from CMAQ simulations conducted with NOx-only and SO2-only emission reductions; the method applies only to cases in which ambient inorganic nitrate is present mostly in the gas phase; that is, in the form of gaseous nitric acid (HNO3). In such instances, the individual effects of NOx and SO2 controls on nitrogen deposition can be approximated by the effects of combined NOx + SO2 controls on the deposition of NOy, (the sum of oxidized nitrogen species) and reduced nitrogen species (NHx), respectively. The benefit of controls at the plant in terms of the decrease in nitrogen deposition to Escambia Bay and watershed is less than 6% of the overall benefit due to regional Clean Air Interstate Rule (CAIR) controls.

Nitrogen oxides from waste incineration: control by selective non-catalytic reduction.

PubMed

Zandaryaa, S; Gavasci, R; Lombardi, F; Fiore, A

2001-01-01

An experimental study of the selective non-catalytic reduction (SNCR) process was carried out to determine the efficiency of NOx removal and NH3 mass balance, the NOx reducing reagent used. Experimental tests were conducted on a full-scale SNCR system installed in a hospital waste incineration plant. Anhydrous NH3 was injected at the boiler entrance for NOx removal. Ammonia was analyzed after each flue-gas treatment unit in order to establish its mass balance and NH3 slip in the stack gas was monitored as well. The effective fraction of NH3 for the thermal NOx reduction was calculated from measured values of injected and residual NH3. Results show that a NOx reduction efficiency in the range of 46.7-76.7% is possible at a NH3/NO molar ratio of 0.9-1.5. The fraction of NH3 used in NOx removal was found to decrease with rising NH3/NO molar ratio. The NH3 slip in the stack gas was very low, below permitted limits, even at the higher NH3 dosages used. No direct correlation was found between the NH3/NO molar ratio and the NH3 slip in the stack gas since the major part of the residual NH3 was converted into ammonium salts in the dry scrubbing reactor and subsequently collected in the fabric filter. Moreover, another fraction of NH3 was dissolved in the scrubbing liquor.

Emission rates of regulated pollutants from current technology heavy-duty diesel and natural gas goods movement vehicles.

PubMed

Thiruvengadam, Arvind; Besch, Marc C; Thiruvengadam, Pragalath; Pradhan, Saroj; Carder, Daniel; Kappanna, Hemanth; Gautam, Mridul; Oshinuga, Adewale; Hogo, Henry; Miyasato, Matt

2015-04-21

Chassis dynamometer emissions testing of 11 heavy-duty goods movement vehicles, including diesel, natural gas, and dual-fuel technology, compliant with US-EPA 2010 emissions standard were conducted. Results of the study show that three-way catalyst (TWC) equipped stoichiometric natural gas vehicles emit 96% lower NOx emissions as compared to selective catalytic reduction (SCR) equipped diesel vehicles. Characteristics of drayage truck vocation, represented by the near-dock and local drayage driving cycles, were linked to high NOx emissions from diesel vehicles equipped with a SCR. Exhaust gas temperatures below 250 °C, for more than 95% duration of the local and near-dock driving cycles, resulted in minimal SCR activity. The low percentage of activity SCR over the local and near-dock cycles contributed to a brake-specific NOx emissions that were 5-7 times higher than in-use certification limit. The study also illustrated the differences between emissions rate measured from chassis dynamometer testing and prediction from the EMFAC model. The results of the study emphasize the need for model inputs relative to SCR performance as a function of driving cycle and engine operation characteristics.

Current status and future trends of SO2 and NOx pollution during the 12th FYP period in Guiyang city of China

NASA Astrophysics Data System (ADS)

Tian, Hezhong; Qiu, Peipei; Cheng, Ke; Gao, Jiajia; Lu, Long; Liu, Kaiyun; Liu, Xingang

2013-04-01

In order to investigate the future trends of SO2 and NOx pollution in Guiyang city of China, the MM5/CALMET/CALPUFF modeling system is applied to assess the effects of air pollution improvement that would result from reduction targets for SO2 and NOx emissions during the 12th Five-Year Plan (2011-2015). Three scenarios are established for the objective year 2015 based on the reference emissions in base year 2010. Scenario analysis and modeling results show that emissions are projected to increase by 26.5% for SO2 and 138.0% for NOx in 2015 Business-As-Usual (BAU) relative to base year 2010, respectively, which will lead to a substantial worsening tendency of SO2 and NOx pollution. In comparison, both the 2015 Policy Reduction (PR) and 2015 Intensive Policy Reduction (IPR) scenarios would contribute to improve the urban air quality. Under 2015 PR scenario, the maximum annual average concentration of SO2 and NOx will reduce by 54.9% and 31.7%, respectively, relative to the year 2010, with only 2.1% of all individual gridded receptors exceed the national air quality standard limits; while the maximum annual average concentrations of SO2 and NOx can reduce further under 2015 IPR scenario and comply well with standards limits. In view of the technical feasibility and cost-effectiveness, the emission reduction targets set in the 2015 PR scenario are regarded as more reasonable in order to further improve the air quality in Guiyang during the 12th FYP period and a series of comprehensive countermeasures should be effectively implemented.

Dedicated exhaust gas recirculation control systems and methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sczomak, David P.; Narayanaswamy, Kushal; Keating, Edward J.

An engine control system of a vehicle includes a fuel control module that controls fuel injection of a first cylinder of an engine based on a first target air/fuel ratio that is fuel lean relative to a stoichiometric air/fuel ratio and that controls fuel injection of a second cylinder of the engine based on a second target air/fuel ratio that is fuel rich relative to stoichiometry. The first cylinder outputs exhaust to a first three way catalyst (TWC), and the second cylinder outputs exhaust to an exhaust gas recirculation (EGR) valve. An EGR control module controls opening of the EGRmore » valve to: (i) a second TWC that reacts with nitrogen oxides (NOx) in the exhaust and outputs ammonia to a selective catalytic reduction (SCR) catalyst; and (ii) a conduit that recirculates exhaust back to an intake system of the engine.« less

Adaptive engine injection for emissions reduction

DOEpatents

Reitz, Rolf D. : Sun, Yong

2008-12-16

NOx and soot emissions from internal combustion engines, and in particular compression ignition (diesel) engines, are reduced by varying fuel injection timing, fuel injection pressure, and injected fuel volume between low and greater engine loads. At low loads, fuel is injected during one or more low-pressure injections occurring at low injection pressures between the start of the intake stroke and approximately 40 degrees before top dead center during the compression stroke. At higher loads, similar injections are used early in each combustion cycle, in addition to later injections which preferably occur between about 90 degrees before top dead center during the compression stroke, and about 90 degrees after top dead center during the expansion stroke (and which most preferably begin at or closely adjacent the end of the compression stroke). These later injections have higher injection pressure, and also lower injected fuel volume, than the earlier injections.

Black carbon, particle number concentration and nitrogen oxide emission factors of random in-use vehicles measured with the on-road chasing method

NASA Astrophysics Data System (ADS)

Ježek, I.; Katrašnik, T.; Westerdahl, D.; Močnik, G.

2015-10-01

The chasing method was used in an on-road measurement campaign, and emission factors (EF) of black carbon (BC), particle number (PN) and nitrogen oxides (NOx) were determined for 139 individual vehicles of different types encountered on the roads. The aggregated results provide EFs for BC, NOx and PN for three vehicle categories: goods vehicles, gasoline and diesel passenger cars. This is the first on-road measurement study where BC EFs of numerous individual diesel cars were determined in real-world driving conditions. We found good agreement between EFs of goods vehicles determined in this campaign and the results of previous studies that used either chasing or remote-sensing measurement techniques. The composition of the sampled car fleet determined from the national vehicle registry information is reflective of Eurostat statistical data on the Slovenian and European vehicle fleet. The median BC EF of diesel and gasoline cars that were in use for less than 5 years decreased by 60 and 47 % from those in use for 5-10 years, respectively; the median NOx and PN EFs of goods vehicles that were in use for less than 5 years decreased from those in use for 5-10 years by 52 and 67 %, respectively. Surprisingly, we found an increase of BC EFs in the newer goods vehicle fleet compared to the 5-10-year old one. The influence of engine maximum power of the measured EFs showed an increase in NOx EF from least to more powerful vehicles with diesel engines. Finally, a disproportionate contribution of high emitters to the total emissions of the measured fleet was found; the top 25 % of emitting diesel cars contributed 63, 47 and 61 % of BC, NOx and PN emissions respectively. With the combination of relatively simple on-road measurements and sophisticated post processing, individual vehicle EF can be determined and useful information about the fleet emissions can be obtained by exactly representing vehicles which contribute disproportionally to vehicle fleet emissions; and monitor how the numerous emission reduction approaches are reflected in on-road driving conditions.

Effects of Particle Filters and Accelerated Engine Replacement on Heavy-Duty Diesel Vehicle Emissions of Black Carbon, Nitrogen Oxides, and Ultrafine Particles

NASA Astrophysics Data System (ADS)

Kirchstetter, T.; Preble, C.; Dallmann, T. R.; DeMartini, S. J.; Tang, N. W.; Kreisberg, N. M.; Hering, S. V.; Harley, R. A.

2013-12-01

Diesel particle filters have become widely used in the United States since the introduction in 2007 of a more stringent exhaust particulate matter emission standard for new heavy-duty diesel vehicle engines. California has instituted additional regulations requiring retrofit or replacement of older in-use engines to accelerate emission reductions and air quality improvements. This presentation summarizes pollutant emission changes measured over several field campaigns at the Port of Oakland in the San Francisco Bay Area associated with diesel particulate filter use and accelerated modernization of the heavy-duty truck fleet. Pollutants in the exhaust plumes of hundreds of heavy-duty trucks en route to the Port were measured in 2009, 2010, 2011, and 2013. Ultrafine particle number, black carbon (BC), nitrogen oxides (NOx), and nitrogen dioxide (NO2) concentrations were measured at a frequency ≤ 1 Hz and normalized to measured carbon dioxide concentrations to quantify fuel-based emission factors (grams of pollutant emitted per kilogram of diesel consumed). The size distribution of particles in truck exhaust plumes was also measured at 1 Hz. In the two most recent campaigns, emissions were linked on a truck-by-truck basis to installed emission control equipment via the matching of transcribed license plates to a Port truck database. Accelerated replacement of older engines with newer engines and retrofit of trucks with diesel particle filters reduced fleet-average emissions of BC and NOx. Preliminary results from the two most recent field campaigns indicate that trucks without diesel particle filters emit 4 times more BC than filter-equipped trucks. Diesel particle filters increase emissions of NO2, however, and filter-equipped trucks have NO2/NOx ratios that are 4 to 7 times greater than trucks without filters. Preliminary findings related to particle size distribution indicate that (a) most trucks emitted particles characterized by a single mode of approximately 100 nm in diameter and (b) new trucks originally equipped with diesel particle filters were 5 to 6 times more likely than filter-retrofitted trucks and trucks without filters to emit particles characterized by a single mode in the range of 10 to 30 nm in diameter.

Prediction of in-use emissions of heavy-duty diesel vehicles from engine testing.

PubMed

Yanowitz, Janet; Graboski, Michael S; McCormick, Robert L

2002-01-15

A model of a heavy-duty vehicle driveline with automatic transmission has been developed for estimating engine speed and load from vehicle speed. The model has been validated using emissions tests conducted on three diesel vehicles on a chassis dynamometer and then on the engines removed from the vehicles tested on an engine dynamometer. Nitrogen oxide (NOx) emissions were proportional to work done by the engine. For two of the engines, the NOx/horsepower(HP) ratio was the same on the engine and on the chassis dynamometer tests. For the third engine NOx/HP was significantly higher from the chassis test, possibly due to the use of dual engine maps. The engine certification test generated consistently less particulate matter emissions on a gram per brake horsepower-hour basis than the Heavy Duty Transient and Central Business District chassis cycles. A good linear correlation (r2 = 0.97 and 0.91) was found between rates of HP increase integrated over the test cycle and PM emissions for both the chassis and the engine tests for two of the vehicles. The model also shows how small changes in vehicle speeds can lead to a doubling of load on the engine. Additionally, the model showed that it is impossible to drive a vehicle cycle equivalent to the heavy-duty engine federal test procedure on these vehicles.

Effectiveness of replacing catalytic converters in LPG-fueled vehicles in Hong Kong

NASA Astrophysics Data System (ADS)

Lyu, X. P.; Guo, H.; Simpson, I. J.; Meinardi, S.; Louie, P. K. K.; Ling, Z. H.; Wang, Y.; Liu, M.; Luk, C. W. Y.; Wang, N.; Blake, D. R.

2015-12-01

Many taxis and public buses are powered by liquefied petroleum gas (LPG) in Hong Kong. With more vehicles using LPG, they have become the major contributor to ambient volatile organic compounds (VOCs) in Hong Kong. An intervention program aimed to reduce the emissions of VOCs and nitrogen oxides (NOx) from LPG-fueled vehicles was implemented by the Hong Kong Government in September 2013. Long-term real-time measurements indicated that the program was remarkably effective in reducing LPG-related VOCs, NOx and nitric oxide (NO) in the atmosphere. Receptor modeling results further revealed that propane, propene, i-butane, n-butane and NO in LPG-fueled vehicle exhaust emissions decreased by 37.3 ± 0.4, 50.2 ± 0.3, 32.9 ± 0.4, 41.1 ± 0.4 and 75.9 ± 0.3 %, respectively, during the implementation of the program. In contrast, despite the reduction of VOCs and NOx, the O3 production following the program increased by 0.25 ± 0.04 ppbv h-1 (4.8 %). Moreover, the production rate of HOx decreased due to the reduction of VOCs, whereas NO reduction resulted in a more significant decrease of the HOx in destruction compared to the decrease in production, and an increase of hydroxyl (OH) and hydroperoxyl (HO2). Analysis of O3-VOCs-NOx sensitivity in ambient air indicated VOC-limited regimes in the O3 formation before and during the program. Moreover, a maximum reduction percentage of NOx (i.e., 29.4 %) and the lowest reduction ratio of VOCs / NOx (i.e., ~ 3 : 1) in LPG-fueled vehicle emissions were determined to give a zero O3 increment. The findings are of great help to future formulation and implementation of control strategies on vehicle emissions in Hong Kong.

Research progress on catalytic denitrification technology in chemical industry

NASA Astrophysics Data System (ADS)

Jin, Yezhi

2017-12-01

In recent years, due to the rising emission of NOx annually, attention has been aroused widely by people on more and more severe environmental problems. This paper first discusses applying NOx removal and control technologies and relating chemical principles. Of many technologies, selective reduction reaction (SCR) is the most widely used. Catalysts, the concentration of NOx at the entrance of SCR catalytic reactor, reaction temperature, NH3/NOx mole ratio and NH3 slip rate analyzed later contributes to the removal efficiency of NOx. Finally, the processing and configuration of SCR de-NOx system are briefly introduced.

Development and integration of a scalable low NOx combustion chamber for a hydrogen-fueled aerogas turbine

NASA Astrophysics Data System (ADS)

Boerner, S.; Funke, H. H.-W.; Hendrick, P.; Recker, E.; Elsing, R.

2013-03-01

The usage of alternative fuels in aircraft industry plays an important role of current aero engine research and development processes. The micromix burning principle allows a secure and low NOx combustion of gaseous hydrogen. The combustion principle is based on the fluid phenomenon of jet in cross flow and achieves a significant lowering in NOx formation by using multiple miniaturized flames. The paper highlights the development and the integration of a combustion chamber, based on the micromix combustion principle, into an Auxiliary Power Unit (APU) GTCP 36-300 with regard to the necessary modifications on the gas turbine and on the engine controller.

Economics of electron beam and electrical discharge processing for post-combustion NO(x) control in internal combustion engines

NASA Astrophysics Data System (ADS)

Penetrante, B. M.

1993-08-01

The physics and chemistry of non-thermal plasma processing for post-combustion NO(x) control in internal combustion engines are discussed. A comparison of electron beam and electrical discharge processing is made regarding their power consumption, radical production, NO(x) removal mechanisms, and by-product formation. Pollution control applications present a good opportunity for transferring pulsed power techniques to the commercial sector. However, unless advances are made to drastically reduce the price and power consumption of electron beam sources and pulsed power systems, these plasma techniques will not become commercially competitive with conventional thermal or surface-catalytic methods.

Effects of hydrotreated vegetable oil on emissions of aerosols and gases from light-duty and medium-duty older technology engines.

PubMed

Bugarski, Aleksandar D; Hummer, Jon A; Vanderslice, Shawn

2016-01-01

This study was conducted to assess the potential of hydrotreated vegetable oil renewable diesel (HVORD) as a control strategy to reduce exposure of workers to diesel aerosols and gases. The effects of HVORD on criteria aerosol and gaseous emissions were compared with those of ultralow sulfur diesel (ULSD). The results of comprehensive testing at four steady-state conditions and one transient cycle were used to characterize the aerosol and gaseous emissions from two older technology engines: (1) a naturally aspirated mechanically controlled and (2) a turbocharged electronically controlled engine. Both engines were equipped with diesel oxidation catalytic converters (DOCs). For all test conditions, both engines emitted measurably lower total mass concentrations of diesel aerosols, total carbon, and elemental carbon when HVORD was used in place of ULSD. For all test conditions, the reductions in total mass concentrations were more substantial for the naturally aspirated than for the turbocharged engine. In the case of the naturally aspirated engine, HVORD also favorably affected total surface area of aerosols deposited in the alveolar region of human lungs (TSAADAR) and the total number concentrations of aerosols. In the case of the turbocharged electronically controlled engine, for some of the test conditions HVORD adversely affected the TSAADAR and total number concentrations of aerosols. In the majority of the test cases involving the naturally aspirated mechanically controlled engine, HVORD favorably affected carbon dioxide (CO2), nitrogen oxides (NOX), and nitric oxide (NO) concentrations, but adversely affected NO2 and total hydrocarbon concentrations, while the effects of the fuels on carbon monoxide (CO) concentrations were masked by the effects of DOC. In the case of the turbocharged electronically controlled engine, the CO2, CO, NOX, NO, and total hydrocarbon concentrations were generally lower when HVORD was used in place of ULSD. The effects of the fuels on NO2 concentrations were masked by the more prominent effects of DOC.

Effects of hydrotreated vegetable oil on emissions of aerosols and gases from light-duty andmedium-duty older technology engines

PubMed Central

Bugarski, Aleksandar D.; Hummer, Jon A.; Vanderslice, Shawn

2017-01-01

This study was conducted to assess the potential of hydrotreated vegetable oil renewable diesel (HVORD) as a control strategy to reduce exposure of workers to diesel aerosols and gases. The effects of HVORD on criteria aerosol and gaseous emissions were compared with those of ultralow sulfur diesel (ULSD). The results of comprehensive testing at four steady-state conditions and one transient cycle were used to characterize the aerosol and gaseous emissions from two older technology engines: (1) a naturally aspirated mechanically controlled and (2) a turbocharged electronically controlled engine. Both engines were equipped with diesel oxidation catalytic converters (DOCs). For all test conditions, both engines emitted measurably lower total mass concentrations of diesel aerosols, total carbon, and elemental carbon when HVORD was used in place of ULSD. For all test conditions, the reductions in total mass concentrations were more substantial for the naturally aspirated than for the turbocharged engine. In the case of the naturally aspirated engine, HVORD also favorably affected total surface area of aerosols deposited in the alveolar region of human lungs (TSAADAR) and the total number concentrations of aerosols. In the case of the turbocharged electronically controlled engine, for some of the test conditions HVORD adversely affected the TSAADAR and total number concentrations of aerosols. In the majority of the test cases involving the naturally aspirated mechanically controlled engine, HVORD favorably affected carbon dioxide (CO2), nitrogen oxides (NOX), and nitric oxide (NO) concentrations, but adversely affected NO2 and total hydrocarbon concentrations, while the effects of the fuels on carbon monoxide (CO) concentrations were masked by the effects of DOC. In the case of the turbocharged electronically controlled engine, the CO2, CO, NOX, NO, and total hydrocarbon concentrations were generally lower when HVORD was used in place of ULSD. The effects of the fuels on NO2 concentrations were masked by the more prominent effects of DOC. PMID:26588029

Control of harmful hydrocarbon species in the exhaust of modern advanced GDI engines

NASA Astrophysics Data System (ADS)

Hasan, A. O.; Abu-jrai, A.; Turner, D.; Tsolakis, A.; Xu, H. M.; Golunski, S. E.; Herreros, J. M.

2016-03-01

A qualitative and quantitative analysis of toxic but currently non-regulated hydrocarbon compounds ranging from C5-C11, before and after a zoned three-way catalytic converter (TWC) in a modern gasoline direct injection (GDI) engine has been studied using gas chromatography-mass spectrometry (GC-MS). The GDI engine has been operated under conventional and advanced combustion modes, which result in better fuel economy and reduced levels of NOx with respect to standard SI operation. However, these fuel-efficient conditions are more challenging for the operation of a conventional TWC, and could lead to higher level of emissions released to the environment. Lean combustion leads to the reduction in pumping losses, fuel consumption and in-cylinder emission formation rates. However, lean HCCI will lead to high levels of unburnt HCs while the presence of oxygen will lower the TWC efficiency for NOx control. The effect on the catalytic conversion of the hydrocarbon species of the addition of hydrogen upstream the catalyst has been also investigated. The highest hydrocarbon engine-out emissions were produced for HCCI engine operation at low engine load operation. The catalyst was able to remove most of the hydrocarbon species to low levels (below the permissible exposure limits) for standard and most of the advanced combustion modes, except for naphthalene (classified as possibly carcinogenic to humans by the International Agency for Research on Cancer) and methyl-naphthalene (which has the potential to cause lung damage). However, when hydrogen was added upstream of the catalyst, the catalyst conversion efficiency in reducing methyl-naphthalene and naphthalene was increased by approximately 21%. This results in simultaneous fuel economy and environmental benefits from the effective combination of advanced combustion and novel aftertreatment systems.

Effect of fuel-air-ratio nonuniformity on emissions of nitrogen oxides

NASA Technical Reports Server (NTRS)

Lyons, V. J.

1981-01-01

The inlet fuel-air ratio nonuniformity is studied to deterine how nitrogen oxide (NOx) emissions are affected. An increase in NOx emissions with increased fuel-air ratio nonuniformity for average equivalence ratios less than 0.7 and a decrease in NOx emissions for average equivalence ratios near stoichiometric is predicted. The degree of uniformityy of fuel-air ratio profiles that is necessary to achieve NOx emissions goals for actual engines that use lean, premixed, prevaporized combustion systems is determined.

On-board measurement of emissions from liquefied petroleum gas, gasoline and diesel powered passenger cars in Algeria.

PubMed

Chikhi, Saâdane; Boughedaoui, Ménouèr; Kerbachi, Rabah; Joumard, Robert

2014-08-01

On-board measurements of unit emissions of CO, HC, NOx and CO₂ were conducted on 17 private cars powered by different types of fuels including gasoline, dual gasoline-liquefied petroleum gas (LPG), gasoline, and diesel. The tests performed revealed the effect of LPG injection technology on unit emissions and made it possible to compare the measured emissions to the European Artemis emission model. A sequential multipoint injection LPG kit with no catalyst installed was found to be the most efficient pollutant reduction device for all of the pollutants, with the exception of the NOx. Specific test results for a sub-group of LPG vehicles revealed that LPG-fueled engines with no catalyst cannot compete with catalyzed gasoline and diesel engines. Vehicle age does not appear to be a determining parameter with regard to vehicle pollutant emissions. A fuel switch to LPG offers many advantages as far as pollutant emissions are concerned, due to LPG's intrinsic characteristics. However, these advantages are being rapidly offset by the strong development of both gasoline and diesel engine technologies and catalyst converters. The LPG's performance on a chassis dynamometer under real driving conditions was better than expected. The enforcement of pollutant emission standards in developing countries is an important step towards introducing clean technology and reducing vehicle emissions. Copyright © 2014. Published by Elsevier B.V.

First assessment on NOx sources for a regional background site of North China using isotopic analysis linked with modelling

NASA Astrophysics Data System (ADS)

Zong, Zheng; Wang, Xiaoping; Tian, Chongguo

2017-04-01

Nitrogen oxides (NOx, including NO and NO2) play an important role in the formation of new particles. Thus NOx emission reduction is one of the most critical steps to improve the air quality, especially in severe air-polluted areas (e.g. the North China). In this study, the sources and conversion mechanisms of NOx were explored at Beihuangcheng Island (BH), a regional background site in North China. Results showed humidity and oxidants were important promoters for the conversion of NOx to nitrate (NO3-) in the atmosphere. Based on nitrogen isotope and an improved Bayesian mixing model, 61.85 ± 2.50%, 24.46 ± 4.02% and 13.69 ± 3.18% of NOx could be attributed to mobile source, coal combustion and biomass burning, respectively, which indicated that mobile source was the primary source for NOx on BH. Seasonally, mobile source was dominant contributor in summer (75.24 ± 5.29%), spring (61.53 ± 4.66%) and autumn (58.72 ± 4.17%). While residential coal combustion confirmed by Mann-Kendall test and moving simulation contributed a main portion of 71.75 ± 11.35% in winter. This work indicated that isotope-modelling is a promising tool for partitioning NOx sources, and provided policy maker with the valuable insight into the NOx reduction in North China.

Impact of biodiesel source material and chemical structure on emissions of criteria pollutants from a heavy-duty engine.

PubMed

McCormick, R L; Graboski, M S; Alleman, T L; Herring, A M; Tyson, K S

2001-05-01

Biodiesel is an oxygenated diesel fuel made from vegetable oils and animal fats by conversion of the triglyceride fats to esters via transesterification. In this study we examined biodiesels produced from a variety of real-world feedstocks as well as pure (technical grade) fatty acid methyl and ethyl esters for emissions performance in a heavy-duty truck engine. The objective was to understand the impact of biodiesel chemical structure, specifically fatty acid chain length and number of double bonds, on emissions of NOx and particulate matter (PM). A group of seven biodiesels produced from real-world feedstocks and 14 produced from pure fatty acids were tested in a heavy-duty truck engine using the U.S. heavy-duty federal test procedure (transient test). It was found that the molecular structure of biodiesel can have a substantial impact on emissions. The properties of density, cetane number, and iodine number were found to be highly correlated with one another. For neat biodiesels, PM emissions were essentially constant at about 0.07 g/bhp-h for all biodiesels as long as density was less than 0.89 g/cm3 or cetane number was greater than about 45. NOx emissions increased with increasing fuel density or decreasing fuel cetane number. Increasing the number of double bonds, quantified as iodine number, correlated with increasing emissions of NOx. Thus the increased NOx observed for some fuels cannot be explained by the NOx/PM tradeoff and is therefore not driven by thermal NO formation. For fully saturated fatty acid chains the NOx emission increased with decreasing chain length for tests using 18, 16, and 12 carbon chain molecules. Additionally, there was no significant difference in NOx or PM emissions for the methyl and ethyl esters of identical fatty acids.

Analysis of alternative pathways for reducing nitrogen oxide emissions.

PubMed

Loughlin, Daniel H; Kaufman, Katherine R; Lenox, Carol S; Hubbell, Bryan J

2015-09-01

Strategies for reducing tropospheric ozone (O3) typically include modifying combustion processes to reduce the formation of nitrogen oxides (NOx) and applying control devices that remove NOx from the exhaust gases of power plants, industrial sources and vehicles. For portions of the U.S., these traditional controls may not be sufficient to achieve the National Ambient Air Quality Standard for ozone. We apply the MARKet ALlocation (MARKAL) energy system model in a sensitivity analysis to explore whether additional NOx reductions can be achieved through extensive electrification of passenger vehicles, adoption of energy efficiency and conservation measures within buildings, and deployment of wind and solar power in the electric sector. Nationally and for each region of the country, we estimate the NOx implications of these measures. Energy efficiency and renewable electricity are shown to reduce NOx beyond traditional controls. Wide-spread light duty vehicle electrification produces varied results, with NOx increasing in some regions and decreasing in others. However, combining vehicle electrification with renewable electricity reduces NOx in all regions. State governments are charged with developing plans that demonstrate how air quality standards will be met and maintained. The results presented here provide an indication of the national and regional NOx reductions available beyond traditional controls via extensive adoption of energy efficiency, renewable electricity, and vehicle electrification.

Formation and emission of nitrogen oxide in gas turbine engines: plume effluent characteristics of TF3O-P111+ and TF33-P9 engines. Final technical report, 1 November-17 December 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dill, J.W.; Sowa, W.A.; Samuelsen, G.S.

1996-06-30

Phase I of this project focused on the creation of a spatial emissions map of the plume effluent in the exhaust stream directly behind the engine in a jet engine test cell (JETC). Both afterburning TF30-P111+ and non-after-burning TF33-P9 engines were tested. Measurements were taken in conjunction with actual engine tests for validity of the data. Temperature, oxides of nitrogen (NOx), carbon monoxide (CO) concentration, and velocity were among the characteristics measured radially and axially in the plume for each engine type. The main focus of this study was on NOx, consisting of nitric oxide (NO) and nitrogen dioxide (NO2).more » Measurements in the P111+ plume reveal levels of NOx above 300 ppm along the centerline of the effluent. A dip in the NOx emissions at afterburner shows signs of a reburning and/or dilution effect by the atmospheric combustion in the effluent. Significant amounts of NO2 are present in the effluent over the entire power range. Temperatures at military power reach 1100 deg F along the centerline, and CO values are below 80 ppm. Carbon monoxide concentrations decrease from idle to military power (full power, no afterburner), then rise sharply in afterburner. The CO peaks shift outward from centerline as do the temperatures due to the radial geometry of the afterburner combustion (over 10 percent CO at 2850 deg F).« less

[Selective catalytic reduction of NOx over Pd/CeZr/TiO2/Al2O3 wire-mesh honeycomb catalysts].

PubMed

Sun, Hong; Quan, Xie; Zhang, Yao-bin; Zhao, Ya-zhi

2008-06-01

Pd/CeZr/TiO2/Al2O3 wire-mesh honeycomb catalyst was prepared by sol-gel and impregnation. Furthermore, selective catalytic reduction of NOx over Pd/CeZr/TiO2/Al2O3 wire-mesh honeycomb catalyst with propylene under lean burn condition was studied. The effects of the concentration of tetra-n-butyl titanate and dipcoat cycles on TiO2 washcoat were studied by SEM, and the effects of Pd concentration, O2 concentration and gas velocity on catalytic activity were investigated. The experimental results showed that the TiO2 washcoat on wire-mesh support is even and crack-free when the support is impregnated in 20.0% tetra- n-butyl titanate sol for 2 cycles. The NOx conversion decreases with Pd concentration increase. When Pd concentration is 0.23%, NOx conversion is highest. NOx conversion increases with oxygen concentration increase in the range of 1.5%-6.0%. However, when oxygen concentration is higher than 6.0%, NOx conversion decreases with increasing oxygen concentration. The NOx conversion decreases with gas velocity increase and its effect is severer at high temperature than low temperature.

Comparison of numerical results and multicavity purge and rim seal data with extensions to dynamics

NASA Astrophysics Data System (ADS)

Athavale, Mahesh; Przekwas, Andrzej J.; Hendricks, Robert C.; Steinetz, Bruce M.

1995-05-01

The computation of flows within interconnected, multiple-disk cavities shows strong interaction between the cavities and the power stream. For this reason, simulations of single cavities in such cases are not realistic; the complete, linked configuration must be considered. Unsteady flow fields affect engine stability and can engender power-stream-driven secondary flows that produce local hot spotting or general cavity heating. Further, a concentric whirling rotor produces a circumferential pressure wave, but a statically eccentric whirling rotor produces a radial wave; both waves affect cavity ingestion and the stability of the entire engine. It is strongly suggested that seals be used to enhance turbojet engine stability. Simple devices, such as swirl brakes, honeycomb inserts, and new seal configurations, should be considered. The cost effectiveness of the NASA Lewis Research Center seals program can be expressed in terms of program goals (e.g., the Integrated High-pressure/Temperature Engine Technology (IHPTET) cannot be achieved without such a program), cost (savings to $250 million/1-percent decrease in specific fuel consumption), and indirect benefits (reduction of atmospheric NO(x) and CO2 and reduction of powerplant downtime).

Comparison of Numerical Results and Multicavity Purge and Rim Seal Data with Extensions to Dynamics

NASA Technical Reports Server (NTRS)

Athavale, Mahesh; Przekwas, Andrzej J.; Hendricks, Robert C.; Steinetz, Bruce M.

1995-01-01

The computation of flows within interconnected, multiple-disk cavities shows strong interaction between the cavities and the power stream. For this reason, simulations of single cavities in such cases are not realistic; the complete, linked configuration must be considered. Unsteady flow fields affect engine stability and can engender power-stream-driven secondary flows that produce local hot spotting or general cavity heating. Further, a concentric whirling rotor produces a circumferential pressure wave, but a statically eccentric whirling rotor produces a radial wave; both waves affect cavity ingestion and the stability of the entire engine. It is strongly suggested that seals be used to enhance turbojet engine stability. Simple devices, such as swirl brakes, honeycomb inserts, and new seal configurations, should be considered. The cost effectiveness of the NASA Lewis Research Center seals program can be expressed in terms of program goals (e.g., the Integrated High-pressure/Temperature Engine Technology (IHPTET) cannot be achieved without such a program), cost (savings to $250 million/1-percent decrease in specific fuel consumption), and indirect benefits (reduction of atmospheric NO(x) and CO2 and reduction of powerplant downtime).

Experimental assessment of the potential to decrease diesel NOx emissions beyond minimum requirements for Euro 6 Real Drive Emissions (RDE) compliance.

PubMed

Triantafyllopoulos, Georgios; Katsaounis, Dimitrios; Karamitros, Dimitrios; Ntziachristos, Leonidas; Samaras, Zissis

2018-03-15

The objective of this study was to test the potential for NO x emissions improvements on a typical Euro 6 diesel vehicle, following modifications to its emissions control system, under Real Drive Emissions (RDE) testing conditions. A commercially available car was selected and was first measured in its original configuration according to RDE on the road and an initial conformity factor (CF) of 5.4 was determined. Subsequent engine calibration and installation of a Selective Catalytic Reduction (SCR) device were conducted and tested on a fully transient engine dyno setup, which precisely reproduced the engine operation under the on-road RDE test. The NO x reduction achieved with those upgrades was 90%, leading to a CF of 0.53, with no CO 2 or fuel consumption penalty. These findings demonstrate that diesel vehicles can reach low NO x levels under real world driving conditions, when well-designed modern exhaust aftertreatment components are installed and properly calibrated. Copyright © 2017 Elsevier B.V. All rights reserved.

Experimental investigation of homogeneous charge compression ignition combustion of biodiesel fuel with external mixture formation in a CI engine.

PubMed

Ganesh, D; Nagarajan, G; Ganesan, S

2014-01-01

In parallel to the interest in renewable fuels, there has also been increased interest in homogeneous charge compression ignition (HCCI) combustion. HCCI engines are being actively developed because they have the potential to be highly efficient and to produce low emissions. Even though HCCI has been researched extensively, few challenges still exist. These include controlling the combustion at higher loads and the formation of a homogeneous mixture. To obtain better homogeneity, in the present investigation external mixture formation method was adopted, in which the fuel vaporiser was used to achieve excellent HCCI combustion in a single cylinder air-cooled direct injection diesel engine. In continuation of our previous works, in the current study a vaporised jatropha methyl ester (JME) was mixed with air to form a homogeneous mixture and inducted into the cylinder during the intake stroke to analyze the combustion, emission and performance characteristics. To control the early ignition of JME vapor-air mixture, cooled (30 °C) Exhaust gas recirculation (EGR) technique was adopted. The experimental result shows 81% reduction in NOx and 72% reduction in smoke emission.

Pollution Reduction Technology Program, Turboprop Engines, Phase 1

NASA Technical Reports Server (NTRS)

Anderson, R. D.; Herman, A. S.; Tomlinson, J. G.; Vaught, J. M.; Verdouw, A. J.

1976-01-01

Exhaust pollutant emissions were measured from a 501-D22A turboprop engine combustor and three low emission combustor types -- reverse flow, prechamber, and staged fuel, operating over a fuel-air ratio range of .0096 to .020. The EPAP LTO cycle data were obtained for a total of nineteen configurations. Hydrocarbon emissions were reduced from 15.0 to .3 lb/1000 Hp-Hr/cycle, CO from 31.5 to 4.6 lb/1000 Hp-Hr/cycle with an increase in NOx of 17 percent, which is still 25% below the program goal. The smoke number was reduced from 59 to 17. Emissions given here are for the reverse flow Mod. IV combustor which is the best candidate for further development into eventual use with the 501-D22A turboprop engine. Even lower emissions were obtained with the advanced technology combustors.

Chemical Modeling for Large-Eddy Simulation of Turbulent Combustion

DTIC Science & Technology

2009-03-31

formation or NOx chemistry . The surrogate composition and its future use dictate the choice of modules that have to be included in the combined skeletal ...Stanford University Mechanical Engineering Department Stanford, CA 94305-3030 Submitted to: Dr. Julian M. Tishkoff Air Force Office of Scientific... engines , such as particulate matter, carbon monoxide CO, and oxides of nitrogen NOx , all contributing at different levels to the greenhouse effect and

Kinetic and spectroscopic study of catalysts for water-gas shift and nitrogen oxide removal

NASA Astrophysics Data System (ADS)

Kispersky, Vincent Frederick

Nitrogen oxides (NOx) are formed in high temperature combustion processes such as in power generation and motor vehicles. Increasingly stringent regulation of these harmful emissions continues to drive interest in developing, understanding and studying new catalytic formulations for exhaust aftertreatment. For mobile sources, predominantly heavy duty diesel engines, selective catalytic reduction (SCR) with NH3 has become the principal means of NO x abatement. An alternative technology developed, but now surpassed by SCR, is NOx Storage Reduction (NSR) catalysis. Both technologies have been studied in our laboratory and are the basis for this dissertation. We studied seven different lean NOx trap (LNT) monolith formulations for NSR ranging from 0.6 to 6.2 wt.% Pt and 4 to 20 wt.% Ba loadings on γ-Al 2O3. The noble metal component of a LNT oxidizes NO to NO 2 aiding in the storage of NO2 on the alkaline earth component. Before the storage component saturates, a reductant such as H2 is introduced into the vehicular exhaust and the stored NOx is released and reduced to N2. Once the storage component is free of NOx, reductant flow is ceased and storage is begun anew. Our research focused on understanding the effects that CO2 and H2O have on the storage capacity of the LNT over short as well as extended periods of time. We found that for high Ba loadings, CO 2 had a consistently detrimental effect on the fast NOx storage capacity (NSC), defined as the amount of NOx the catalyst can store before 1% of the inlet NOx is measured in the reactor outlet. Over long NOx storage periods, CO2 continued to inhibit storage compared to the same catalyst in CO2 free conditions. On low loadings of Ba, however, the inhibition of CO2 was significantly reduced. We found that the loading dependent characteristics of the Ba phase affected the way in which CO2 adsorbed on the storage component, which greatly affected the stability of the species on lower Ba loadings. The less stable adsorbed CO2 proved less competitive for NOx sorption sites, explaining the weak reduction of NSC by CO2 on low Ba loadings. Contrary to CO2, H2O exhibited both beneficial and inhibitory effects on the NSC. Over long periods of time, and at high Ba loadings, the addition of H2O in the feed increased the NSC, attributed to enhanced O2 spillover on the hydroxylated Ba surface allowing greater access to available NOx storage sites. When the Ba loading was reduced, the interaction sphere of Pt particles with the Ba storage component required for O2 to spillover to assist in NOx storage was reduced. Thus, despite the enhanced spillover capacity of oxygen on the hydroxylated storage component other NSC decreasing effects of H2O addition, such as Ba agglomeration, became more dominant and reduced the NSC. Recent developments in selective catalytic reduction have shown Cu and Fe/chabazite (CHA) based zeolites to be particularly well suited to sustaining high catalytic rates without degradation in the harsh environment of diesel engine exhaust. Little has been published about these catalysts as the academic community has just recently learned about the materials and their commercial implementation. Using operando X-ray absorption spectroscopy, combined with first-principles thermodynamics simulations and kinetic analysis, we have studied the nature of the Cu active site on Cu/SSZ-13, Cu/SAPO-34 and Cu/ZSM-5. Examining the catalysts under operando standard SCR conditions (300 ppm NO, 300 ppm NH3, 5% O2, 5% H2O and 5% CO2) showed the catalyst to be in a mixed Cu(I)-Cu(II) oxidation state. Neither the amount of Cu(I) nor Cu(II) individually correlated with the different rates measured on the various zeolite catalysts, and so we proposed that the SCR reaction progresses via a redox mechanism requiring both Cu(I) and Cu(II). First principles thermodynamic calculations found that the redox couple of Cu(I)H2O and Cu(II)(OH)2 were the most thermodynamically stable species of any of the OxHy variants modeled on Cu. The redox nature of the Cu active site was further investigated in a follow up study isolating the reducing portion of the SCR by removing O 2 from the reaction feed. Cutting off O2 drove the catalyst into a highly reduced state dominated by Cu(I) while removing a reductant drove the Cu into the fully oxidized state. Our research shows that not only is redox a vital part of the SCR reaction on Cu/zeolites, but that the oxidation state of the active site is highly sensitive to the gas environment. The water-gas shift (WGS) reaction is an industrially important step in H2 generation from steam reforming. I have had the opportunity to contribute to a number of studies in WGS by studying the catalysts in FTIR. We studied numerous catalytic formulations including Fe promoted Pd/Al 2O3 and Au/TiO2. We found that the Fe promoted the WGS rate of the catalyst by a factor of 160 compared to the Fe free Pd/Al 2O3. The reduced Fe promoter efficiently split H2O, typically the role performed by reducible supports, and the nearby noble metal particles provided spillover H2 to maintain the reduced Fe phase necessary to split H2O. Our study of Au/TiO2 involved the development of a modified operando transmission IR cell with ultra-low dead volume allowing for fast switching isotope experiments over the catalyst. The isotope switching experiments showed that only CO adsorbed on Au0 sites was an active surface intermediate at 120°C. Counting the amount of active surface Au atoms for the reaction ruled out the Au particle surface and perimeter atoms as the dominant active sites and confirmed our previous finding that the active site was composed mostly of low coordinated corner Au atoms.

NOx Emissions from a Rotating Detonation-wave Engine

NASA Astrophysics Data System (ADS)

Kailasanath, Kazhikathra; Schwer, Douglas

2016-11-01

Rotating detonation-wave engines (RDE) are a form of continuous detonation-wave engines. They potentially provide further gains in performance than an intermittent or pulsed detonation-wave engine (PDE). The overall flow field in an idealized RDE, primarily consisting of two concentric cylinders, has been discussed in previous meetings. Because of the high pressures involved and the lack of adequate reaction mechanisms for this regime, previous simulations have typically used simplified chemistry models. However, understanding the exhaust species concentrations in propulsion devices is important for both performance considerations as well as estimating pollutant emissions. Progress towards addressing this need will be discussed in this talk. In this approach, an induction parameter model is used for simulating the detonation but a more detailed finite-chemistry model including NOx chemistry is used in the expansion flow region, where the pressures are lower and the uncertainties in the chemistry model are greatly reduced. Results show that overall radical concentrations in the exhaust flow are substantially lower than from earlier predictions with simplified models. Results to date show that NOx emissions are not a problem for the RDE due to the short residence times and the nature of the flow field. Furthermore, simulations show that the amount of NOx can be further reduced by tailoring the fluid dynamics within the RDE.

Evidence of the Importance of Nox4 in Production of Hypertension in Dahl Salt-Sensitive Rats.

PubMed

Cowley, Allen W; Yang, Chun; Zheleznova, Nadezhda N; Staruschenko, Alexander; Kurth, Theresa; Rein, Lisa; Kumar, Vikash; Sadovnikov, Katherine; Dayton, Alex; Hoffman, Matthew; Ryan, Robert P; Skelton, Meredith M; Salehpour, Fahimeh; Ranji, Mahsa; Geurts, Aron

2016-02-01

This study reports the consequences of knocking out NADPH (nicotinamide adenine dinucleotide phosphate) oxidase 4 (Nox4) on the development of hypertension and kidney injury in the Dahl salt-sensitive (SS) rat. Zinc finger nuclease injection of single-cell SS embryos was used to create an 8 base-pair frame-shift deletion of Nox4, resulting in a loss of the ≈68 kDa band in Western blot analysis of renal cortical tissue of the knock out of Nox4 in the SS rat (SS(Nox4-/-)) rats. SS(Nox4-/-) rats exhibited a significant reduction of salt-induced hypertension compared with SS rats after 21 days of 4.0% NaCl diet (134±5 versus 151±3 mm Hg in SS) and a significant reduction of albuminuria, tubular casts, and glomerular injury. Optical fluorescence 3-dimensional cryoimaging revealed significantly higher redox ratios (NADH/FAD [reduced nicotinamide adenine dinucleotide/flavin adenine dinucleotide]) in the kidneys of SS(Nox4-/-) rats even when fed the 0.4% NaCl diet, indicating greater levels of mitochondrial electron transport chain metabolic activity and reduced oxidative stress compared with SS rats. Before the development of hypertension, RNA expression levels of Nox subunits Nox2, p67(phox), and p22(phox) were found to be significantly lower (P<0.05) in SS(Nox4-/-) compared with SS rats in the renal cortex. Thus, the mutation of Nox4 seems to modify transcription of several genes in ways that contribute to the protective effects observed in the SS(Nox4-/-) rats. We conclude that the reduced renal injury and attenuated blood pressure response to high salt in the SS(Nox4-/-) rat could be the result of multiple pathways, including gene transcription, mitochondrial energetics, oxidative stress, and protein matrix production impacted by the knock out of Nox4. © 2015 American Heart Association, Inc.

Impact of oxygenated additives to diesel-biodiesel blends in the context of performance and emissions characteristics of a CI engine

NASA Astrophysics Data System (ADS)

Mahmudul, H. M.; Hagos, Ftwi Y.; Mamat, Rizalman; Abdullah, Abdul A.

2016-11-01

Butanol is receiving huge interest in the area of alternative fuel in the compression ignition (CI) engines. In this work, butanol is used as an oxygenated additive to diesel and biodiesel blend fuels to evaluate the performance and emission of CI engine. The commercially available pure diesel fuel (D100) and 80% commercially available diesel- biodiesel bled (5% biodiesel and 95% by volume) and 20% butanol (BU20) fuels were investigated to evaluate the effects of the fuel blends on the performance and exhaust emissions of a single cylinder diesel engine. The experiment was conducted at fixed load of 75% with the five engine speeds (from 1200-2400 rpm with an interval of 300 rpm). The engine performance parameters such as power, torque, fuel consumption and thermal efficiency and exhaust gas emissions such as nitrogen oxides, carbon monoxide, and exhaust gas temperature were analysed from the experimental data. The results shows that although butanol addition has caused a slight reduction in power and torque values (11.1% and 3.5%, respectively), the emission values of the engine were improved. With respect to the exhaust gas temperature, CO and NOx emissions, of BU20 is reported to have reduction by 17.7%, 20% and 3%, respectively than the B100. Therefore, butanol can be used as a fuel additive to diesel-biodiesel blends.

SOURCEBOOK: NOX CONTROL TECHNOLOGY DATA

EPA Science Inventory

The report, a compilation of available information on the control of nitrogen oxide (NOx) emissions from stationary sources, is provided to assist new source permitting activities by regulatory agencies. he sources covered are combustion turbines, internal combustion engines, non...

40 CFR 76.7 - Revised NOX emission limitations for Group 1, Phase II boilers.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Revised NOX emission limitations for Group 1, Phase II boilers. 76.7 Section 76.7 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.7 Revised NOX...

40 CFR 76.7 - Revised NOX emission limitations for Group 1, Phase II boilers.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 17 2012-07-01 2012-07-01 false Revised NOX emission limitations for Group 1, Phase II boilers. 76.7 Section 76.7 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.7 Revised NOX...

40 CFR 76.7 - Revised NOX emission limitations for Group 1, Phase II boilers.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Revised NOX emission limitations for Group 1, Phase II boilers. 76.7 Section 76.7 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.7 Revised NOX...

40 CFR 76.7 - Revised NOX emission limitations for Group 1, Phase II boilers.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Revised NOX emission limitations for Group 1, Phase II boilers. 76.7 Section 76.7 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.7 Revised NOX...

40 CFR 76.7 - Revised NOX emission limitations for Group 1, Phase II boilers.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Revised NOX emission limitations for Group 1, Phase II boilers. 76.7 Section 76.7 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.7 Revised NOX...

40 CFR 75.70 - NOX mass emissions provisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... subpart to the extent that compliance is required by an applicable State or federal NOX mass emission...) For purposes of this subpart, the term “affected unit” shall mean any unit that is subject to a State...” shall mean the permitting authority under an applicable State or federal NOX mass emission reduction...

40 CFR Appendix E to Part 75 - Optional NOX Emissions Estimation Protocol for Gas-Fired Peaking Units and Oil-Fired Peaking Units

Code of Federal Regulations, 2011 CFR

2011-07-01

... according to the following procedures. 2.1.6.1Plot the heat input rate (mmBtu/hr) as the independent (or x... stationary gas turbine, select at least four operating parameters indicative of the turbine's NOX formation... least four operating parameters indicative of the engine's NOX formation characteristics, and define in...

40 CFR 1043.50 - Approval of methods to meet Tier 1 retrofit NOX standards.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Approval of methods to meet Tier 1... SUBJECT TO THE MARPOL PROTOCOL § 1043.50 Approval of methods to meet Tier 1 retrofit NOX standards... enable Pre-Tier 1 engines to meet the Tier 1 NOX standard of regulation 13 of Annex VI. Any person may...

System and method for selective catalytic reduction of nitrogen oxides in combustion exhaust gases

DOEpatents

Sobolevskiy, Anatoly; Rossin, Joseph A

2014-04-08

A multi-stage selective catalytic reduction (SCR) unit (32) provides efficient reduction of NOx and other pollutants from about 50-550.degree. C. in a power plant (19). Hydrogen (24) and ammonia (29) are variably supplied to the SCR unit depending on temperature. An upstream portion (34) of the SCR unit catalyzes NOx+NH.sub.3 reactions above about 200.degree. C. A downstream portion (36) catalyzes NOx+H.sub.2 reactions below about 260.degree. C., and catalyzes oxidation of NH.sub.3, CO, and VOCs with oxygen in the exhaust above about 200.degree. C., efficiently removing NOx and other pollutants over a range of conditions with low slippage of NH.sub.3. An ammonia synthesis unit (28) may be connected to the SCR unit to provide NH.sub.3 as needed, avoiding transport and storage of ammonia or urea at the site. A carbonaceous gasification plant (18) on site may supply hydrogen and nitrogen to the ammonia synthesis unit, and hydrogen to the SCR unit.

Effects of NOx control and plume mixing on nighttime chemical processing of plumes from coal-fired power plants

NASA Astrophysics Data System (ADS)

Brown, Steven S.; Dubé, William P.; Karamchandani, Prakash; Yarwood, Greg; Peischl, Jeff; Ryerson, Thomas B.; Neuman, J. Andrew; Nowak, John B.; Holloway, John S.; Washenfelder, Rebecca A.; Brock, Charles A.; Frost, Gregory J.; Trainer, Michael; Parrish, David D.; Fehsenfeld, Frederick C.; Ravishankara, A. R.

2012-04-01

Coal-fired electric power plants produce a large fraction of total U.S. NOx emissions, but NOx from this sector has been declining in the last decade owing to installation of control technology. Nighttime aircraft intercepts of plumes from two different Texas power plants (Oklaunion near Wichita Falls and W. A. Parish near Houston) with different control technologies demonstrate the effect of these reductions on nighttime NOxoxidation rates. The analysis shows that the spatial extent of nighttime-emitted plumes to be quite limited and that mixing of highly concentrated plume NOx with ambient ozone is a determining factor for its nighttime oxidation. The plume from the uncontrolled plant had full titration of ozone through 74 km/2.4 h of downwind transport that suppressed nighttime oxidation of NO2 to higher oxides of nitrogen across the majority of the plume. The plume from the controlled plant did not have sufficient NOx to titrate background ozone, which led to rapid nighttime oxidation of NO2 during downwind transport. A plume model that includes horizontal mixing and nighttime chemistry reproduces the observed structures of the nitrogen species in the plumes from the two plants. The model shows that NOx controls not only reduce the emissions directly but also lead to an additional overnight NOx loss of 36-44% on average. The maximum reduction for 12 h of transport in darkness was 73%. The results imply that power plant NOxemissions controls may produce a larger than linear reduction in next-day, downwind ozone production following nighttime transport.

N+2 Advanced Low NOx Combustor Technology Final Report

NASA Technical Reports Server (NTRS)

Herbon, John; Aicholtz, John; Hsieh, Shih-Yang; Viars, Philip; Birmaher, Shai; Brown, Dan; Patel, Nayan; Carper, Doug; Cooper, Clay; Fitzgerald, Russell

2017-01-01

In accordance with NASAs technology goals for future subsonic vehicles, this contract identified and developed new combustor concepts toward meeting N+2 generation (2020) LTO (landing and take-off) NOx emissions reduction goal of 75 from the standard adopted at Committee on Aviation Environmental Protection 6 (CAEP6). Based on flame tube emissions, operability, and autoignition testing, one concept was down selected for sector testing at NASA. The N+2 combustor sector successfully demonstrated 75 reduction for LTO NOx (vs. CAEP6) and cruise NOx (vs. 2005 B777-200 reference) while maintaining 99.9 cruise efficiency and no increase in CO and HC emissions.The program also developed enabling technologies for the combustion system including ceramic matrix composites (CMC) liner materials, active combustion control concepts, and laser ignition for improved altitude relight.

Advanced technology for reducing aircraft engine pollution

NASA Technical Reports Server (NTRS)

Jones, R. E.

1973-01-01

Combustor research programs are described whose purpose is to demonstrate significantly lower exhaust emission levels. The proposed EPA regulations covering the allowable levels of emissions will require a major technological effort if these levels are to be met by 1979. Pollution reduction technology is being pursued by NASA through a combination of in-house research, contracted progams, and university grants. In-house research with the swirl-can modular combustor and the double-annular combustor has demonstrated significant reduction in the level of NO(x) emissions. The work is continuing in an attempt to further reduce these levels by improvements in module design and in air-fuel scheduling. Research on the reduction of idle emissions has included the conversion of conventional duplex fuel nozzles to air-assisted nozzles and exploration of the potential improvements possible with fuel staging and variable combustor geometry.

Application of OMI Observations to a Space-Based Indicator of NOx and VOC Controls on Surface Ozone Formation

NASA Technical Reports Server (NTRS)

Duncan, Bryan N.; Yoshida, Yasuko; Olson, Jennifer R.; Sillman, Sanford; Martin, Randall V.; Lamsal, Lok; Hu, Yongtao; Pickering, Kenneth E.; Retscher, Christian; Allen, Dale J.;

Characteristics of NOx emission from Chinese coal-fired power plants equipped with new technologies

NASA Astrophysics Data System (ADS)

Ma, Zizhen; Deng, Jianguo; Li, Zhen; Li, Qing; Zhao, Ping; Wang, Liguo; Sun, Yezhu; Zheng, Hongxian; Pan, Li; Zhao, Shun; Jiang, Jingkun; Wang, Shuxiao; Duan, Lei

2016-04-01

Coal combustion in coal-fired power plants is one of the important anthropogenic NOx sources, especially in China. Many policies and methods aiming at reducing pollutants, such as increasing installed capacity and installing air pollution control devices (APCDs), especially selective catalytic reduction (SCR) units, could alter NOx emission characteristics (NOx concentration, NO2/NOx ratio, and NOx emission factor). This study reported the NOx characteristics of eight new coal-fired power-generating units with different boiler patterns, installed capacities, operating loads, and coal types. The results showed that larger units produced less NOx, and anthracite combustion generated more NOx than bitumite and lignite combustion. During formation, the NOx emission factors varied from 1.81 to 6.14 g/kg, much lower than those of older units at similar scales. This implies that NOx emissions of current and future units could be overestimated if they are based on outdated emission factors. In addition, APCDs, especially SCR, greatly decreased NOx emissions, but increased NO2/NOx ratios. Regardless, the NO2/NOx ratios were lower than 5%, in accordance with the guidelines and supporting the current method for calculating NOx emissions from coal-fired power plants that ignore NO2.

Enhancing SNCR-aided combustion with oxygen addition

DOEpatents

Kobayashi, Hisashi; Wu, Kuang Tsai; Bool, III, Lawrence E.

2004-03-09

NOx emissions from combustion are reduced, NOx reduction efficiency by SNCR is improved, and other efficiencies are realized, by injecting oxygen into a fuel-rich combustion zone under controlled conditions.

Particulate emissions from diesel engines: correlation between engine technology and emissions.

PubMed

Fiebig, Michael; Wiartalla, Andreas; Holderbaum, Bastian; Kiesow, Sebastian

2014-03-07

In the last 30 years, diesel engines have made rapid progress to increased efficiency, environmental protection and comfort for both light- and heavy-duty applications. The technical developments include all issues from fuel to combustion process to exhaust gas aftertreatment. This paper provides a comprehensive summary of the available literature regarding technical developments and their impact on the reduction of pollutant emission. This includes emission legislation, fuel quality, diesel engine- and exhaust gas aftertreatment technologies, as well as particulate composition, with a focus on the mass-related particulate emission of on-road vehicle applications. Diesel engine technologies representative of real-world on-road applications will be highlighted.Internal engine modifications now make it possible to minimize particulate and nitrogen oxide emissions with nearly no reduction in power. Among these modifications are cooled exhaust gas recirculation, optimized injections systems, adapted charging systems and optimized combustion processes with high turbulence. With introduction and optimization of exhaust gas aftertreatment systems, such as the diesel oxidation catalyst and the diesel particulate trap, as well as NOx-reduction systems, pollutant emissions have been significantly decreased. Today, sulfur poisoning of diesel oxidation catalysts is no longer considered a problem due to the low-sulfur fuel used in Europe. In the future, there will be an increased use of bio-fuels, which generally have a positive impact on the particulate emissions and do not increase the particle number emissions.Since the introduction of the EU emissions legislation, all emission limits have been reduced by over 90%. Further steps can be expected in the future. Retrospectively, the particulate emissions of modern diesel engines with respect to quality and quantity cannot be compared with those of older engines. Internal engine modifications lead to a clear reduction of the particulate emissions without a negative impact on the particulate-size distribution towards smaller particles. The residual particles can be trapped in a diesel particulate trap independent of their size or the engine operating mode. The usage of a wall-flow diesel particulate filter leads to an extreme reduction of the emitted particulate mass and number, approaching 100%. A reduced particulate mass emission is always connected to a reduced particle number emission.

Particulate emissions from diesel engines: correlation between engine technology and emissions

PubMed Central

2014-01-01

In the last 30 years, diesel engines have made rapid progress to increased efficiency, environmental protection and comfort for both light- and heavy-duty applications. The technical developments include all issues from fuel to combustion process to exhaust gas aftertreatment. This paper provides a comprehensive summary of the available literature regarding technical developments and their impact on the reduction of pollutant emission. This includes emission legislation, fuel quality, diesel engine- and exhaust gas aftertreatment technologies, as well as particulate composition, with a focus on the mass-related particulate emission of on-road vehicle applications. Diesel engine technologies representative of real-world on-road applications will be highlighted. Internal engine modifications now make it possible to minimize particulate and nitrogen oxide emissions with nearly no reduction in power. Among these modifications are cooled exhaust gas recirculation, optimized injections systems, adapted charging systems and optimized combustion processes with high turbulence. With introduction and optimization of exhaust gas aftertreatment systems, such as the diesel oxidation catalyst and the diesel particulate trap, as well as NOx-reduction systems, pollutant emissions have been significantly decreased. Today, sulfur poisoning of diesel oxidation catalysts is no longer considered a problem due to the low-sulfur fuel used in Europe. In the future, there will be an increased use of bio-fuels, which generally have a positive impact on the particulate emissions and do not increase the particle number emissions. Since the introduction of the EU emissions legislation, all emission limits have been reduced by over 90%. Further steps can be expected in the future. Retrospectively, the particulate emissions of modern diesel engines with respect to quality and quantity cannot be compared with those of older engines. Internal engine modifications lead to a clear reduction of the particulate emissions without a negative impact on the particulate-size distribution towards smaller particles. The residual particles can be trapped in a diesel particulate trap independent of their size or the engine operating mode. The usage of a wall-flow diesel particulate filter leads to an extreme reduction of the emitted particulate mass and number, approaching 100%. A reduced particulate mass emission is always connected to a reduced particle number emission. PMID:24606725

Regeneration and sulfur poisoning behavior of In/H-BEA catalyst for NOx reduction by CH4

NASA Astrophysics Data System (ADS)

Pan, Hua; Jian, Yanfei; Yu, Yanke; He, Chi; Shen, Zhenxing; Liu, Hongxia

2017-04-01

Sulfur poisoning and regeneration behavior of In/H-BEA catalyst were carried out in NOx reduction by CH4. In/H-BEA catalyst exhibited a poor resistance to sulfur dioxide after addition of 200 ppm SO2 and 10 vol.% H2O into NO reduction with CH4 at 450 °C for 45 h. Sulfur poisoning of In/H-BEA was attributed to the inhibition of NOx adsorption on Brønsted acid sites, suppression of reaction intermediates generation on the active sites, and the formation of surface sulfate species. The formation of surface sulfate reduced the availability of surface active sites, blocked the pore structure and decreased the surface area of catalyst. These changes in chemical and textural properties resulted in a severe loss in the activity of sulfated In/H-BEA catalyst for NO reduction with CH4. H2 reduction is a promising technology for regeneration of In/H-BEA deactivated by SO2 for removing NOx from lean-burn and diesel exhausts. Indium sulfate could be reduced by H2 to InO+ with In2O3 and In(OH)2+ as the intermediates. The optimal parameters of H2 reduction was regeneration temperature of 400 °C and regeneration time of 60 min which completely recovered the catalytic activity of In/H-BEA.

Ozone response to emission reductions in the southeastern United States

NASA Astrophysics Data System (ADS)

Blanchard, Charles L.; Hidy, George M.

2018-06-01

Ozone (O3) formation in the southeastern US is studied in relation to nitrogen oxide (NOx) emissions using long-term (1990s-2015) surface measurements of the Southeastern Aerosol Research and Characterization (SEARCH) network, U.S. Environmental Protection Agency (EPA) O3 measurements, and EPA Clean Air Status and Trends Network (CASTNET) nitrate deposition data. Annual fourth-highest daily peak 8 h O3 mixing ratios at EPA monitoring sites in Georgia, Alabama, and Mississippi exhibit statistically significant (p < 0.0001) linear correlations with annual NOx emissions in those states between 1996 and 2015. The annual fourth-highest daily peak 8 h O3 mixing ratios declined toward values of ˜ 45-50 ppbv and monthly O3 maxima decreased at rates averaging ˜ 1-1.5 ppbv yr-1. Mean annual total oxidized nitrogen (NOy) mixing ratios at SEARCH sites declined in proportion to NOx emission reductions. CASTNET data show declining wet and dry nitrate deposition since the late 1990s, with total (wet plus dry) nitrate deposition fluxes decreasing linearly in proportion to reductions of NOx emissions by ˜ 60 % in Alabama and Georgia. Annual nitrate deposition rates at Georgia and Alabama CASTNET sites correspond to 30 % of Georgia emission rates and 36 % of Alabama emission rates, respectively. The fraction of NOx emissions lost to deposition has not changed. SEARCH and CASTNET sites exhibit downward trends in mean annual nitric acid (HNO3) concentrations. Observed relationships of O3 to NOz (NOy-NOx) support past model predictions of increases in cycling of NO and increasing responsiveness of O3 to NOx. The study data provide a long-term record that can be used to examine the accuracy of process relationships embedded in modeling efforts. Quantifying observed O3 trends and relating them to reductions in ambient NOy species concentrations offers key insights into processes of general relevance to air quality management and provides important information supporting strategies for reducing O3 mixing ratios.

Butanol / Gasoline Mercury CRADA Report

DTIC Science & Technology

2015-03-01

oxygenated fuel, which increases in-cylinder temperatures and thus generates higher NOx emissions. 3.2 Modifications to the SPC-TB 3.2.1 Data Collection...emissions.  Emissions of oxides of Nitrogen (NOx) are higher with oxygenated fuel. NOx generation is a function of the time spent at high temperature ...pressure in the combustion chamber. The engines run leaner and hotter with oxygenated fuel, which increases in-cylinder temperatures and thus

Nitrogen oxides emissions from thermal power plants in china: current status and future predictions.

PubMed

Tian, Hezhong; Liu, Kaiyun; Hao, Jiming; Wang, Yan; Gao, Jiajia; Qiu, Peipei; Zhu, Chuanyong

2013-10-01

Increasing emissions of nitrogen oxides (NOx) over the Chinese mainland have been of great concern due to their adverse impacts on regional air quality and public health. To explore and obtain the temporal and spatial characteristics of NOx emissions from thermal power plants in China, a unit-based method is developed. The method assesses NOx emissions based on detailed information on unit capacity, boiler and burner patterns, feed fuel types, emission control technologies, and geographical locations. The national total NOx emissions in 2010 are estimated at 7801.6 kt, of which 5495.8 kt is released from coal-fired power plant units of considerable size between 300 and 1000 MW. The top provincial emitter is Shandong where plants are densely concentrated. The average NOx-intensity is estimated at 2.28 g/kWh, markedly higher than that of developed countries, mainly owing to the inadequate application of high-efficiency denitrification devices such as selective catalytic reduction (SCR). Future NOx emissions are predicted by applying scenario analysis, indicating that a reduction of about 40% by the year 2020 can be achieved compared with emissions in 2010. These results suggest that NOx emissions from Chinese thermal power plants could be substantially mitigated within 10 years if reasonable control measures were implemented effectively.

77 FR 54384 - Nonconformance Penalties for On-Highway Heavy-Duty Diesel Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-05

...EPA is taking final action to establish nonconformance penalties (NCPs) for manufacturers of heavy heavy-duty diesel engines (HHDDE) in model years 2012 and later for emissions of oxides of nitrogen (NOX) because we have found the criteria for NCPs and the Clean Air Act have been met. The NOX standards to which these NCPs apply were established by a rule published on January 18, 2001. In general, NCPs allow a manufacturer of heavy-duty engines (HDEs) whose engines do not conform to applicable emission standards, but do not exceed a designated upper limit, to be issued a certificate of conformity upon payment of a monetary penalty to the United States Government. The upper limit associated with these NCPs is 0.50 grams of NOX per brake horsepower-hour (g/bhp-hr). This Final Rule specifies certain parameters that are entered into the preexisting penalty formulas along with the emissions of the engine and the incorporation of other factors to determine the amount a manufacturer must pay. Key parameters that determine the NCP a manufacturer must pay are EPA's estimated cost of compliance for a near worst-case engine and the degree to which the engine exceeds the emission standard (as measured from production engines). EPA proposed NCPs for medium heavy duty diesel engines. However, EPA is not taking final action with regard to NCPs for these engines at this time because EPA has not completed its review of the data and comments regarding these engines.

Emissions of an AVCO Lycoming 0-320-DIAD air cooled light aircraft engine as a function of fuel-air ratio, timing, and air temperature and humidity

NASA Technical Reports Server (NTRS)

Meng, P. R.; Skorobatckyi, M.; Cosgrove, D. V.; Kempke, E. E., Jr.

1976-01-01

A carbureted aircraft engine was operated over a range of test conditions to establish the exhaust levels over the EPA seven-mode emissions cycle. Baseline (full rich production limit) exhaust emissions at an induction air temperature of 59 F and near zero relative humidity were 90 percent of the EPA standard for HC, 35 percent for NOx, and 161 percent for CO. Changes in ignition timing around the standard 25 deg BTDC from 30 deg BTDC to 20 deg BTDC had little effect on the exhaust emissions. Retarding the timing to 15 deg BTDC increased both the HC and CO emissions and decreased NOx emissions. HC and CO emissions decreased as the carburetor was leaned out, while NOx emissions increased. The EPA emission standards were marginally achieved at two leanout conditions. Variations in the quantity of cooling air flow over the engine had no effect on exhaust emissions. Temperature-humidity effects at the higher values of air temperature and relative humidity tested indicated that the HC and CO emissions increased significantly, while the NOx emissions decreased.

500 MW demonstration of advanced wall-fired combustion techniques for the reduction of nitrogen oxide emissions from coal-fired boilers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sorge, J.N.; Larrimore, C.L.; Slatsky, M.D.

1997-12-31

This paper discusses the technical progress of a US Department of Energy Innovative Clean Coal Technology project demonstrating advanced wall-fired combustion techniques for the reduction of nitrogen oxide (NOx) emissions from coal-fired boilers. The primary objectives of the demonstration is to determine the long-term NOx reduction performance of advanced overfire air (AOFA), low NOx burners (LNB), and advanced digital control optimization methodologies applied in a stepwise fashion to a 500 MW boiler. The focus of this paper is to report (1) on the installation of three on-line carbon-in-ash monitors and (2) the design and results to date from the advancedmore » digital control/optimization phase of the project.« less

Regional Attribution of Ozone Production and Associated Radiative Forcing: a Step to Crediting NOx Emission Reductions

NASA Astrophysics Data System (ADS)

Naik, V.; Mauzerall, D. L.; Horowitz, L.; Schwarzkopf, D.; Ramaswamy, V.; Oppenheimer, M.

2004-12-01

The global distribution of tropospheric ozone (O3) depends on the location of emissions of its precursors in addition to chemical and dynamical factors. The global picture of O3 forcing is, therefore, a sum of regional forcings arising from emissions of precursors from different sources. The Kyoto Protocol does not include ozone as a greenhouse gas, and emission reductions of ozone precursors made under Kyoto or any similar agreement would presently receive no credit. In this study, we quantitatively estimate the contribution of emissions of nitrogen oxides (NOx), the primary limiting O3 precursor in the non-urban atmosphere, from specific countries and regions of the world to global O3 concentration distributions. We then estimate radiative forcing resulting from the regional perturbations of NOx emissions. This analysis is intended as an early step towards incorporating O3 into the Kyoto Protocol or any successor agreement. Under such a system countries could obtain credit for improvements in local air quality that result in reductions of O3 concentrations because of the associated reductions in radiative forcing. We use the global chemistry transport model, MOZART-2, to simulate the global O3 distribution for base year 1990 and perturbations to this distribution caused by a 10% percent reduction in the base emissions of NOx from the United States, Europe, East Asia, India, South America, and Africa. We calculate the radiative forcing for the simulated base and perturbed O3 distributions using the GFDL radiative transfer model. The difference between the radiative forcing from O3 for the base and perturbed distributions provides an estimate of the marginal radiative forcing from a region's emissions of NOx. We will present a quantitative analysis of the magnitude, spatial, and temporal distribution of radiative forcing resulting from marginal changes in the NOx emissions from each region.

Life cycle inventory energy consumption and emissions for biodiesel versus petroleum diesel fueled construction vehicles.

PubMed

Pang, Shih-Hao; Frey, H Christopher; Rasdorf, William J

2009-08-15

Substitution of soy-based biodiesel fuels for petroleum diesel will alter life cycle emissions for construction vehicles. A life cycle inventory was used to estimate fuel cycle energy consumption and emissions of selected pollutants and greenhouse gases. Real-world measurements using a portable emission measurement system (PEMS) were made forfive backhoes, four front-end loaders, and six motor graders on both fuels from which fuel consumption and tailpipe emission factors of CO, HC, NO(x), and PM were estimated. Life cycle fossil energy reductions are estimated it 9% for B20 and 42% for B100 versus petroleum diesel based on the current national energy mix. Fuel cycle emissions will contribute a larger share of total life cycle emissions as new engines enter the in-use fleet. The average differences in life cycle emissions for B20 versus diesel are: 3.5% higher for NO(x); 11.8% lower for PM, 1.6% higher for HC, and 4.1% lower for CO. Local urban tailpipe emissions are estimated to be 24% lower for HC, 20% lower for CO, 17% lower for PM, and 0.9% lower for NO(x). Thus, there are environmental trade-offs such as for rural vs urban areas. The key sources of uncertainty in the B20 LCI are vehicle emission factors.

Method for modeling driving cycles, fuel use, and emissions for over snow vehicles.

PubMed

Hu, Jiangchuan; Frey, H Christopher; Sandhu, Gurdas S; Graver, Brandon M; Bishop, Gary A; Schuchmann, Brent G; Ray, John D

2014-07-15

As input to a winter use plan, activity, fuel use, and tailpipe exhaust emissions of over snow vehicles (OSV), including five snow coaches and one snowmobile, were measured on a designated route in Yellowstone National Park (YNP). Engine load was quantified in terms of vehicle specific power (VSP), which is a function of speed, acceleration, and road grade. Compared to highway vehicles, VSP for OSVs is more sensitive to rolling resistance and less sensitive to aerodynamic drag. Fuel use rates increased linearly (R2>0.96) with VSP. For gasoline-fueled OSVs, fuel-based emission rates of carbon monoxide (CO) and nitrogen oxides (NOx) typically increased with increasing fuel use rate, with some cases of very high CO emissions. For the diesel OSVs, which had selective catalytic reduction and diesel particulate filters, fuel-based NOx and particulate matter (PM) emission rates were not sensitive to fuel flow rate, and the emission controls were effective. Inter vehicle variability in cycle average fuel use and emissions rates for CO and NOx was substantial. However, there was relatively little inter-cycle variation in cycle average fuel use and emission rates when comparing driving cycles. Recommendations are made regarding how real-world OSV activity, fuel use, and emissions data can be improved.

Combustion and NOx emissions in deep-air-staging combustion of char in a circulating fluidized bed

NASA Astrophysics Data System (ADS)

Gong, Zhiqiang; Wang, Zhentong; Wang, Lei; Du, Aixun

2017-10-01

Combustion and NOx emissions in deep-air-staging (with higher level secondary air (SA) injection) combustion of char have been investigated in a CFB test rig. A good fluidized condition and uniform temperature distribution can be achieved with injection of higher level SA. NOx emission decreases with injection of higher level SA and the reduction effect is more obvious at higher temperature. NOx emission decreases with combustion temperature increasing for char combustion.

Application of microwave energy in the control of DPM, oxides of nitrogen and VOC emissions

NASA Astrophysics Data System (ADS)

Pallavkar, Sameer M.

The emissions of DPM (diesel particulate matter), NOx (oxides of nitrogen), and toxic VOCs (volatile organic compounds) from diesel engine exhaust gases and other sources such as chemical process industry and manufacturing industry have been a great environmental and health concern. Most control technologies for these emissions require elevated temperatures. The use of microwave energy as a source of heat energy, however, has not been fully explored. In this study, the microwave energy was used as the energy source in three separate emission control processes, namely, the regeneration of diesel particulate filter (DPF) for DPM control, the NOx reduction using a platinum catalyst, and the VOC destruction involving a ceramic based material. The study has demonstrated that microwave heating is an effective method in providing heat for the studied processes. The control efficiencies associated with the microwave-assisted processes have been observed to be high and acceptable. Further research, however, is required for the commercial use of these technologies.

Diesel engine fuel consumption and emission analysis using steam generated non-surfactant water-in-diesel emulsion fuel

NASA Astrophysics Data System (ADS)

Avianto Sugeng, Dhani; Zahari, Mohamad Fathur Hafeezat Mohd; Muhsin Ithnin, Ahmad; Jazair Yahya, Wira

2017-10-01

Efforts in making water in diesel emulsion (W/D) with the absence of surfactant have been developed to address the issues of long-term stability and the dependence on surfactants. This paper discusses an alternative formation method of a non-surfactant W/D, e.g. by steam condensation. By injecting steam into a batch of colder diesel fuel, fine water droplets are formed and suspended in the fuel forming an emulsion. The droplets are confirmed to be in the size range of hundreds of nanometers. The emissions of NOx is reduced by a maximum of 71%, whereas the CO and UHC emissions are increased by maximum respectively 180% and a surprising 517%. Not less interesting is the lower BSFC which was measured at a maximum reduction of 18.4%. These results on emission analysis together with the brake specific fuel consumption confirm this method to resemble the combustion behaviour of a conventional emulsion fuel of lower NOx and BSFC, yet higher CO and UHC

Diesel Emission Control -- Sulfur Effects (DECSE) Program; Phase I Interim Data Report No. 2: NO{sub x} Adsorber Catalysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

DOE; ORNL; NREL

1999-10-15

The Diesel Emission Control-Sulfur Effects (DECSE) is a joint government/industry program to determine the impact of diesel fuel sulfur levels on emission control systems whose use could lower emissions of nitrogen oxides (NOx) and particulate matter (PM) from on-highway trucks in the 2002--2004 model years. Phase 1 of the program was developed with the following objectives in mind: (1) evaluate the effects of varying the level of sulfur content in the fuel on the emission reduction performance of four emission control technologies; and (2) measure and compare the effects of up to 250 hours of aging on selected devices formore » multiple levels of fuel sulfur content. This interim report discusses the results of the DECSE test program that demonstrates the potential of NOx adsorber catalyst technology across the range of diesel engine operation with a fuel economy penalty less than 4%.« less

Aircraft gas turbine low-power emissions reduction technology program

NASA Technical Reports Server (NTRS)

Dodds, W. J.; Gleason, C. C.; Bahr, D. W.

1978-01-01

Advanced aircraft turbine engine combustor technology was used to reduce low-power emissions of carbon monoxide and unburned hydrocarbons to levels significantly lower than those which were achieved with current technology. Three combustor design concepts, which were designated as the hot-wall liner concept, the recuperative-cooled liner concept, and the catalyst converter concept, were evaluated in a series of CF6-50 engine size 40 degree-sector combustor rig tests. Twenty-one configurations were tested at operating conditions spanning the design condition which was an inlet temperature and pressure of 422 K and 304 kPa, a reference velocity of 23 m/s and a fuel-air-ration of 10.5 g/kg. At the design condition typical of aircraft turbine engine ground idle operation, the best configurations of all three concepts met the stringent emission goals which were 10, 1, and 4 g/kg for CO, HC, and Nox, respectively.

40 CFR 76.12 - Phase I NOX compliance extension.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.12 Phase I NOX compliance extension. (a... outage. (iii) Fuel and energy balance summaries and power and other consumption requirements (including...

40 CFR 76.12 - Phase I NOX compliance extension.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.12 Phase I NOX compliance extension. (a... outage. (iii) Fuel and energy balance summaries and power and other consumption requirements (including...

40 CFR 76.12 - Phase I NOX compliance extension.

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.12 Phase I NOX compliance extension. (a... outage. (iii) Fuel and energy balance summaries and power and other consumption requirements (including...

40 CFR 76.12 - Phase I NOX compliance extension.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.12 Phase I NOX compliance extension. (a... outage. (iii) Fuel and energy balance summaries and power and other consumption requirements (including...

40 CFR 76.12 - Phase I NOX compliance extension.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.12 Phase I NOX compliance extension. (a... outage. (iii) Fuel and energy balance summaries and power and other consumption requirements (including...

DIESEL NOX CONTROL APPLICATION

EPA Science Inventory

The paper gives results of a project to design, develop, and demonstrate a diesel engine nitrogen oxide (NOx) and particulate matter (PM) control package that will meet the U.S. Navy's emission control requirements. (NOTE: In 1994, EPA issued a Notice for Proposed Rule Making (NP...

Impacts of Aging Emission Control Systems on In-Use Heavy-Duty Diesel Truck Emission Rates

NASA Astrophysics Data System (ADS)

Preble, C.; Cados, T.; Harley, R.; Kirchstetter, T.

2017-12-01

Heavy-duty diesel trucks are a major source of nitrogen oxides (NOx) and black carbon (BC) in urban environments, contributing to persistent ozone and particulate matter air quality problems. Recently, diesel particle filter (DPF) and selective catalytic reduction (SCR) emission control systems have become standard equipment on new trucks. Particle filters can also be installed as a retrofit on older engines. Prior work has shown that exhaust filters and SCR systems effectively reduce BC and NOx emission rates by up to 90 and 80%, respectively (Preble et al., ES&T 2015). There is concern, however, that DPFs may promote the formation of ultrafine particles (UFP) and increase tailpipe emissions of nitrogen dioxide (NO2). Additionally, urea-based SCR systems for NOx control may form nitrous oxide (N2O), an important contributor to stratospheric ozone depletion. The effectiveness of these emission controls has been thoroughly evaluated in the laboratory, but the long-term durability of in-use systems and their impacts on co-emitted species have not been well characterized. To evaluate the in-use performance of DPF and SCR systems, pollutant emissions from thousands of diesel trucks were measured over several years at the Port of Oakland and the Caldecott Tunnel in the San Francisco Bay Area. Pollutants present in the exhaust plumes of individual trucks were measured at high time resolution (≥1 Hz) as trucks passed under a mobile lab stationed on an overpass. Fuel-based emission factors (g pollutant emitted per kg fuel burned) were calculated for individual trucks and linked via recorded license plates to vehicle attributes, including engine model year and installed emission control systems. Use of DPFs reduced the BC emission rate by up to 95% at both locations. SCR systems were more effective at reducing NOx emissions under the uphill, highway driving conditions at the Caldecott Tunnel. The emission rates of co-emitted species NO2, UFP, and N2O depended on driving mode. Some DPFs on trucks with 2007-2009 model year engines showed deterioration or failure in filter performance, leading to higher BC emission rates compared to the average for trucks without filters. Emission inventories may underestimate total on-road emissions from diesel trucks, especially if particle filter failure rates continue to increase over time.

On the Effects of NOx Emission Control and Drought on an Ozone-Polluted Ecosystem

NASA Astrophysics Data System (ADS)

Pusede, S.; Geddes, J.; Buysse, C. E.; Esperanza, A.; Najacht, E.; Anderson, J. F.; Bailey, C. B.; Munyan, J.

2017-12-01

Regulatory emission controls are typically designed to reduce ozone when ozone is highest. However, high ozone concentrations are often asynchronous with periods of the greatest ozone harm to plants and ecosystems, particularly during drought. Because ozone production chemistry is nonlinear, emissions reductions designed to be effective in polluted cities may have a range of effects on downwind ecosystems. Here, we investigate the influence of regional NOx emission controls on ozone pollution in Sequoia National Park (SNP). First, we show that steep declines in NOx throughout the region have had smaller impacts in SNP than in cities upwind, and that these reductions have been least effective at times of day and year when plants are most sensitive to ozone. Second, in recent years (2012-2015), California experienced the worst drought in recorded history. We present observational evidence of the ozone response in SNP to drought conditions, finding that the drought altered the chemical sensitivity of local ozone production to NOx emissions and, hence, the effectiveness of NOx emission controls. We show that drought impacts on the ozone sensitivity to NOx have persisted at least two years since the drought ended.

On-road measurement of regulated pollutants from diesel and CNG buses with urea selective catalytic reduction systems

NASA Astrophysics Data System (ADS)

Guo, Jiadong; Ge, Yunshan; Hao, Lijun; Tan, Jianwei; Li, Jiaqiang; Feng, Xiangyu

2014-12-01

In this study, emissions from 13 buses operated in Beijing, including two Euro-III diesel buses, four Euro-IV diesel buses, three Euro-V diesel buses and four Euro-V CNG buses, were characterized in real world conditions. All of the buses tested were fitted with selective catalytic reduction (SCR) systems except for the Euro-III diesel buses. A SEMTECH-DS was used for testing the gaseous pollutants, and an electric low pressure impactor (ELPI) was used for measuring of particle numbers and size distributions. A comparison was made based on emission performance of these buses by employing the VSP approach and fuel- based emissions factors. Diesel buses emitted less CO and THC but more NOx and PM pollutants than CNG buses. The NOx reduction efficiencies of the SCR systems for CNG buses were higher because of the high exhaust temperature and high NO2/NOx ratio, whereas the efficiencies for diesel buses were lower. This resulted in extremely low NOx emissions from CNG buses, but the high NO2/NOx ratio needs further study. Failures of urea injection in the SCR systems were detected in this research, which resulted in very high NOx emissions. The CNG buses also emitted smaller numbers of particles and less particle mass with the presence of oxidation catalysts. Diesel buses satisfying the Euro-V standard performed better than Euro-IV and Euro-III diesel buses in terms of emission performance, except for more nuclei mode particles. Most of time, the Euro-IV diesel buses show no advantages in CO and NOx emissions compared with the Euro-III diesel buses.

On the effectiveness of nitrogen oxide reductions as a control over ammonium nitrate aerosol

NASA Astrophysics Data System (ADS)

Pusede, S. E.; Duffey, K. C.; Shusterman, A. A.; Saleh, A.; Laughner, J. L.; Wooldridge, P. J.; Zhang, Q.; Parworth, C. L.; Kim, H.; Capps, S. L.; Valin, L. C.; Cappa, C. D.; Fried, A.; Walega, J.; Nowak, J. B.; Hoff, R. M.; Berkoff, T. A.; Beyersdorf, A. J.; Olson, J.; Crawford, J. H.; Cohen, R. C.

2015-10-01

Nitrogen oxides (NOx) have fallen steadily across the US over the last fifteen years. At the same time, due to patterns diesel truck activities, NOx concentrations decrease on weekends relative to weekdays, largely without co-occurring changes in other gas-phase emissions. These trends taken together provide two independent constraints on the role of NOx in the nonlinear chemistry of atmospheric oxidation. In this context, we interpret interannual trends in wintertime ammonium nitrate (NH4NO3) in the San Joaquin Valley of California, a location with the worst aerosol pollution in the US and where a large portion of aerosol mass is NH4NO3. Here, we show that NOx reductions have simultaneously decreased nighttime and increased daytime NH4NO3 production over the last decade. We find a substantial decrease in NH4NO3 since 2000 and conclude that this decrease is due to reduced nitrate radical-initiated production at night in residual layers that are decoupled from fresh emissions at the surface. Further reductions in NOx are imminent in California, and nationwide, and we make a quantitative prediction of the response of NH4NO3. We show that the combination of rapid chemical production and efficient NH4NO3 loss via deposition of gas-phase nitric acid implies high aerosol days in cities in the San Joaquin Valley air basin are responsive to local changes in NOx within those individual cities. Our calculations indicate that large decreases in NOx in the future will not only lower wintertime NH4NO3 concentrations, they will also cause a transition in the dominant NH4NO3 source from nighttime to daytime chemistry.

On the effectiveness of nitrogen oxide reductions as a control over ammonium nitrate aerosol

NASA Astrophysics Data System (ADS)

Pusede, S. E.; Duffey, K. C.; Shusterman, A. A.; Saleh, A.; Laughner, J. L.; Wooldridge, P. J.; Zhang, Q.; Parworth, C. L.; Kim, H.; Capps, S. L.; Valin, L. C.; Cappa, C. D.; Fried, A.; Walega, J.; Nowak, J. B.; Weinheimer, A. J.; Hoff, R. M.; Berkoff, T. A.; Beyersdorf, A. J.; Olson, J.; Crawford, J. H.; Cohen, R. C.

2016-03-01

Nitrogen oxides (NOx) have fallen steadily across the US over the last 15 years. At the same time, NOx concentrations decrease on weekends relative to weekdays, largely without co-occurring changes in other gas-phase emissions, due to patterns of diesel truck activities. These trends taken together provide two independent constraints on the role of NOx in the nonlinear chemistry of atmospheric oxidation. In this context, we interpret interannual trends in wintertime ammonium nitrate (NH4NO3) in the San Joaquin Valley of California, a location with the worst aerosol pollution in the US and where a large portion of aerosol mass is NH4NO3. Here, we show that NOx reductions have simultaneously decreased nighttime and increased daytime NH4NO3 production over the last decade. We find a substantial decrease in NH4NO3 since 2000 and conclude that this decrease is due to reduced nitrate radical-initiated production at night in residual layers that are decoupled from fresh emissions at the surface. Further reductions in NOx are imminent in California, and nationwide, and we make a quantitative prediction of the response of NH4NO3. We show that the combination of rapid chemical production and efficient NH4NO3 loss via deposition of gas-phase nitric acid implies that high aerosol days in cities in the San Joaquin Valley air basin are responsive to local changes in NOx within those individual cities. Our calculations indicate that large decreases in NOx in the future will not only lower wintertime NH4NO3 concentrations but also cause a transition in the dominant NH4NO3 source from nighttime to daytime chemistry.

Effects of Low Sulfur Fuel and a Catalyzed Particle Trap on the Composition and Toxicity of Diesel Emissions

PubMed Central

McDonald, Jacob D.; Harrod, Kevin S.; Seagrave, JeanClare; Seilkop, Steven K.; Mauderly, Joe L.

2004-01-01

In this study we compared a “baseline” condition of uncontrolled diesel engine exhaust (DEE) emissions generated with current (circa 2003) certification fuel to an emissions-reduction (ER) case with low sulfur fuel and a catalyzed particle trap. Lung toxicity assessments (resistance to respiratory viral infection, lung inflammation, and oxidative stress) were performed on mice (C57Bl/6) exposed by inhalation (6 hr/day for 7 days). The engine was operated identically (same engine load) in both cases, and the inhalation exposures were conducted at the same exhaust dilution rate. For baseline DEE, this dilution resulted in a particle mass (PM) concentration of approximately 200 μg/m3 PM, whereas the ER reduced the PM and almost every other measured constituent [except nitrogen oxides (NOx)] to near background levels in the exposure atmospheres. These measurements included PM, PM size distribution, PM composition (carbon, ions, elements), NOx, carbon monoxide, speciated/total volatile hydrocarbons, and several classes of semi-volatile organic compounds. After exposure concluded, one group of mice was immediately sacrificed and assessed for inflammation and oxidative stress in lung homogenate. Another group of mice were intratracheally instilled with respiratory syncytial virus (RSV), and RSV lung clearance and inflammation was assessed 4 days later. Baseline DEE produced statistically significant biological effects for all measured parameters. The use of low sulfur fuel and a catalyzed trap either completely or nearly eliminated the effects. PMID:15345344

Design and operation of a medium speed 12-cylinder coal-fueled diesel engine. Phase 2: Improvements

NASA Astrophysics Data System (ADS)

Confer, G. L.; Hsu, B. D.; McDowell, R. E.; Gal, E.; Vankleunen, W.; Kaldor, S.; Mengel, M.

Under the sponsorship of the US Department of Energy, General Electric has been pioneering the development of a coal fired diesel engine to power a locomotive. The feasibility of using a coal water slurry (CWS) mixture as a fuel in a medium speed diesel engine has been demonstrated with the first successful locomotive systems test in 1991 on the GE Transportation Systems test track in Erie, PA. Phase 2 of the development process incorporates the results of the programs research in durable engine parts, improved combustion efficiency, and emissions reduction. A GE 7FDL12 engine has been built using diamond insert injector nozzles, tungsten carbide coated piston rings, and tungsten carbide coated liners to overcome power assembly wear. Electronic controlled fuel injection for both diesel pilot and main CWS injector were incorporated to control injection timing. An envelop filter and copper oxide sorbent system were used to cleanup engine emissions. The system is capable of removing over 99% of the particulates, 90% of the SO2, and 85% of NO(x).

Experimental study on particulate and NOx emissions of a diesel engine fueled with ultra low sulfur diesel, RME-diesel blends and PME-diesel blends.

PubMed

Zhu, Lei; Zhang, Wugao; Liu, Wei; Huang, Zhen

2010-02-01

Ultra low sulfur diesel and two different kinds of biodiesel fuels blended with baseline diesel fuel in 5% and 20% v/v were tested in a Cummins 4BTA direct injection diesel engine, with a turbocharger and an intercooler. Experiments were conducted under five engine loads at two steady speeds (1500 rpm and 2500 rpm). The study aims at investigating the engine performance, NO(x) emission, smoke opacity, PM composition, PM size distribution and comparing the impacts of low sulfur content of biodiesel with ULSD on the particulate emission. The results indicate that, compared to base diesel fuel, the increase of biodiesel in blends could cause certain increase in both brake specific fuel consumption and brake thermal efficiency. Compared with baseline diesel fuel, the biodiesel blends bring about more NO(x) emissions. With the proportion of biodiesel increase in blends, the smoke opacity decreases, while total particle number concentration increases. Meanwhile the ULSD gives lower NO(x) emissions, smoke opacity and total number concentration than those of baseline diesel fuel. In addition, the percentages of SOF and sulfate in particulates increase with biodiesel in blends, while the dry soot friction decreases obviously. Compared with baseline diesel fuel, the biodiesel blends increase the total nucleation number concentration, while ULSD reduces the total nucleation number concentration effectively, although they all have lower sulfur content. It means that, for ULSD, the lower sulfur content is the dominant factor for suppressing nucleation particles formation, while for biodiesel blends, lower volatile, lower aromatic content and higher oxygen content of biodiesel are key factors for improving the nucleation particles formation. The results demonstrate that the higher NO(x) emission and total nucleation number concentration are considered as the big obstacles of the application of biodiesel in diesel engine. Copyright 2009 Elsevier B.V. All rights reserved.

The use of tyre pyrolysis oil in diesel engines.

PubMed

Murugan, S; Ramaswamy, M C; Nagarajan, G

2008-12-01

Tests have been carried out to evaluate the performance, emission, and combustion characteristics of a single cylinder direct injection diesel engine fueled with 10%, 30%, and 50% of tyre pyrolysis oil (TPO) blended with diesel fuel (DF). The TPO was derived from waste automobile tyres through vacuum pyrolysis. The combustion parameters such as heat release rate, cylinder peak pressure, and maximum rate of pressure rise also analysed. Results showed that the brake thermal efficiency of the engine fueled with TPO-DF blends increased with an increase in blend concentration and reduction of DF concentration. NO(x), HC, CO, and smoke emissions were found to be higher at higher loads due to the high aromatic content and longer ignition delay. The cylinder peak pressure increased from 71 bars to 74 bars. The ignition delays were longer than with DF. It is concluded that it is possible to use tyre pyrolysis oil in diesel engines as an alternate fuel in the future.

Organic Rankine cycle - review and research directions in engine applications

NASA Astrophysics Data System (ADS)

Panesar, Angad

2017-11-01

Waste heat to power conversion using Organic Rankine Cycles (ORC) is expected to play an important role in CO2 reductions from diesel engines. Firstly, a review of automotive ORCs is presented focusing on the pure working fluids, thermal architectures and expanders. The discussion includes, but is not limited to: R245fa, ethanol and water as fluids; series, parallel and cascade as architectures; dry saturated, superheated and supercritical as expansion conditions; and scroll, radial turbine and piston as expansion machines. Secondly, research direction in versatile expander and holistic architecture (NOx + CO2) are proposed. Benefits of using the proposed unconventional approaches are quantified using Ricardo Wave and Aspen HYSYS for diesel engine and ORC modelling. Results indicate that, the implementation of versatile piston expander tolerant to two-phase and using cyclopentane can potentially increase the highway drive cycle power by 8%. Furthermore, holistic architecture offering complete utilisation of charge air and exhaust recirculation heat increased the performance noticeably to 5% of engine power at the design point condition.

Current Trends in Water-in-Diesel Emulsion as a Fuel

PubMed Central

Yahaya Khan, Mohammed; Abdul Karim, Z. A.; Aziz, A. Rashid A.; Tan, Isa M.

2014-01-01

Water-in-diesel emulsion (WiDE) is an alternative fuel for CI engines that can be employed with the existing engine setup with no additional engine retrofitting. It has benefits of simultaneous reduction of both NOx and particulate matters in addition to its impact in the combustion efficiency improvement, although this needs further investigation. This review paper addresses the type of emulsion, the microexplosion phenomenon, emulsion stability and physiochemical improvement, and effect of water content on the combustion and emissions of WiDE fuel. The review also covers the recent experimental methodologies used in the investigation of WiDE for both transport and stationary engine applications. In this review, the fuel injection pump and spray nozzle arrangement has been found to be the most critical components as far as the secondary atomization is concerned and further investigation of the effect of these components in the microexplosion of the emulsion is suggested to be center of focus. PMID:24563631

Role of sectoral and multi-pollutant emission control strategies in improving atmospheric visibility in the Yangtze River Delta, China.

PubMed

Huang, Kan; Fu, Joshua S; Gao, Yang; Dong, Xinyi; Zhuang, Guoshun; Lin, Yanfen

2014-01-01

The Community Multi-scale Air Quality modeling system is used to investigate the response of atmospheric visibility to the emission reduction from different sectors (i.e. industries, traffic and power plants) in the Yangtze River Delta, China. Visibility improvement from exclusive reduction of NOx or VOC emission was most inefficient. Sulfate and organic aerosol would rebound if NOx emission was exclusively reduced from any emission sector. The most efficient way to improve the atmospheric visibility was proven to be the multi-pollutant control strategies. Simultaneous emission reductions (20-50%) on NOx, VOC and PM from the industrial and mobile sectors could result in 0.3-1.0 km visibility improvement. And the emission controls on both NOx (85%) and SO2 (90%) from power plants gained the largest visibility improvement of up to 4.0 km among all the scenarios. The seasonal visibility improvement subject to emission controls was higher in summer while lower in the other seasons. Copyright © 2013 Elsevier Ltd. All rights reserved.

Changes in inorganic fine particulate matter sensitivities to precursors due to large-scale US emissions reductions.

PubMed

Holt, Jareth; Selin, Noelle E; Solomon, Susan

2015-04-21

We examined the impact of large US emissions changes, similar to those estimated to have occurred between 2005 and 2012 (high and low emissions cases, respectively), on inorganic PM2.5 sensitivities to further NOx, SO2, and NH3 emissions reductions using the chemical transport model GEOS-Chem. Sensitivities to SO2 emissions are larger year-round and across the US in the low emissions case than the high emissions case due to more aqueous-phase SO2 oxidation. Sensitivities to winter NOx emissions are larger in the low emissions case, more than 2× those of the high emissions case in parts of the northern Midwest. Sensitivities to NH3 emissions are smaller (∼40%) in the low emissions case, year-round, and across the US. Differences in NOx and NH3 sensitivities indicate an altered atmospheric acidity. Larger sensitivities to SO2 and NOx in the low emissions case imply that reducing these emissions may improve air quality more now than they would have in 2005; conversely, NH3 reductions may not improve air quality as much as previously assumed.

Radio-Frequency-Controlled Urea Dosing for NH3-SCR Catalysts: NH3 Storage Influence to Catalyst Performance under Transient Conditions

PubMed Central

Dietrich, Markus; Hagen, Gunter; Reitmeier, Willibald; Burger, Katharina; Hien, Markus; Grass, Philippe; Kubinski, David; Visser, Jaco; Moos, Ralf

2017-01-01

Current developments in exhaust gas aftertreatment led to a huge mistrust in diesel driven passenger cars due to their NOx emissions being too high. The selective catalytic reduction (SCR) with ammonia (NH3) as reducing agent is the only approach today with the capability to meet upcoming emission limits. Therefore, the radio-frequency-based (RF) catalyst state determination to monitor the NH3 loading on SCR catalysts has a huge potential in emission reduction. Recent work on this topic proved the basic capability of this technique under realistic conditions on an engine test bench. In these studies, an RF system calibration for the serial type SCR catalyst Cu-SSZ-13 was developed and different approaches for a temperature dependent NH3 storage were determined. This paper continues this work and uses a fully calibrated RF-SCR system under transient conditions to compare different directly measured and controlled NH3 storage levels, and NH3 target curves. It could be clearly demonstrated that the right NH3 target curve, together with a direct control on the desired level by the RF system, is able to operate the SCR system with the maximum possible NOx conversion efficiency and without NH3 slip. PMID:29182589

Emission Characteristics of A P and W Axially Staged Sector Combustor

NASA Technical Reports Server (NTRS)

He, Zhuohui J.; Wey, Changlie; Chang, Clarence T.; Lee, Chi Ming; Surgenor, Angela D.; Kopp-Vaughan, Kristin; Cheung, Albert

2016-01-01

Emission characteristics of a three-cup P and W Axially Controlled Stoichiometry (ACS) sector combustor are reported in this article. Multiple injection points and fuel staging strategies are used in this combustor design. Pilot-stage injectors are located on the front dome plate of the combustor, and main-stage injectors are positioned on the top and bottom of the combustor liners downstream. Low power configuration uses only pilot-stage injectors. Main-stage injectors are added to high power configuration to help distribute fuel more evenly and achieve overall lean burn yielding very low NOx emissions. Combustion efficiencies at four ICAO LTO conditions were all above 99%. Three EINOx emissions correlation equations were developed based on the experimental data to describe the NOx emission trends of this combustor concept. For the 7% and 30% engine power conditions, NOx emissions are obtained with the low power configuration, and the EINOx values are 6.16 and 6.81. The high power configuration was used to assess 85% and 100% engine power NOx emissions, with measured EINOx values of 4.58 and 7.45, respectively. The overall landing-takeoff cycle NOx emissions are about 12% relative to ICAO CAEP/6 level.

NOx reduction in catalytically stabilized thermal burners. Annual report, pril 1, 1988-March 31, 1989

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pfefferle, L.D.

1989-09-01

Catalytically stabilized combustors can be designed to combine the high reaction rates of thermal combustors with low-NOx emissions. The objectives of the research are to understand why the CST burner has inherently low-NOx emissions and whether preexisting NOx can be reduced in-situ in the post-flame zone of a CST burner. Initial results indicate that reduced NOx emissions are, at least for some operating conditions, due to more than just the ability to stabilize combustion at low temperatures. The next phase of the investigation will focus on isothermal flow-tube kinetics studies to isolate catalytic and thermal effects.

Understanding the effectiveness of precursor reductions in lowering 8-hr ozone concentrations--Part II. The eastern United States.

PubMed

Reynolds, Steven D; Blanchard, Charles L; Ziman, Stephen D

2004-11-01

Analyses of ozone (O3) measurements in conjunction with photochemical modeling were used to assess the feasibility of attaining the federal 8-hr O3 standard in the eastern United States. Various combinations of volatile organic compound (VOC) and oxides of nitrogen (NOx) emission reductions were effective in lowering modeled peak 1-hr O3 concentrations. VOC emissions reductions alone had only a modest impact on modeled peak 8-hr O3 concentrations. Anthropogenic NOx emissions reductions of 46-86% of 1996 base case values were needed to reach the level of the 8-hr standard in some areas. As NOx emissions are reduced, O3 production efficiency increases, which accounts for the less than proportional response of calculated 8-hr O3 levels. Such increases in O3 production efficiency also were noted in previous modeling work for central California. O3 production in some urban core areas, such as New York City and Chicago, IL, was found to be VOC-limited. In these areas, moderate NOx emissions reductions may be accompanied by increases in peak 8-hr O3 levels. The findings help to explain differences in historical trends in 1- and 8-hr O3 levels and have serious implications for the feasibility of attaining the 8-hr O3 standard in several areas of the eastern United States.

Analytical properties of some commercially available nitrate reductase enzymes evaluated as replacements for cadmium in automated, semiautomated, and manual colorimetric methods for determination of nitrate plus nitrite in water

USGS Publications Warehouse

Patton, Charles J.; Kryskalla, Jennifer R.

2013-01-01

A multiyear research effort at the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL) evaluated several commercially available nitrate reductase (NaR) enzymes as replacements for toxic cadmium in longstanding automated colorimetric air-segmented continuous-flow analyzer (CFA) methods for determining nitrate plus nitrite (NOx) in water. This research culminated in USGS approved standard- and low-level enzymatic reduction, colorimetric automated discrete analyzer NOx methods that have been in routine operation at the NWQL since October 2011. The enzyme used in these methods (AtNaR2) is a product of recombinant expression of NaR from Arabidopsis thaliana (L.) Heynh. (mouseear cress) in the yeast Pichia pastoris. Because the scope of the validation report for these new automated discrete analyzer methods, published as U.S. Geological Survey Techniques and Methods 5–B8, was limited to performance benchmarks and operational details, extensive foundational research with different enzymes—primarily YNaR1, a product of recombinant expression of NaR from Pichia angusta in the yeast Pichia pastoris—remained unpublished until now. This report documents research and development at the NWQL that was foundational to development and validation of the discrete analyzer methods. It includes: (1) details of instrumentation used to acquire kinetics data for several NaR enzymes in the presence and absence of known or suspected inhibitors in relation to reaction temperature and reaction pH; and (2) validation results—method detection limits, precision and bias estimates, spike recoveries, and interference studies—for standard- and low-level automated colorimetric CFA-YNaR1 reduction NOx methods in relation to corresponding USGS approved CFA cadmium-reduction (CdR) NOx methods. The cornerstone of this validation is paired sample statistical and graphical analysis of NOx concentrations from more than 3,800 geographically and seasonally diverse surface-water and groundwater samples that were analyzed in parallel by CFA-CdR and CFA enzyme-reduction methods. Finally, (3) demonstration of a semiautomated batch procedure in which 2-milliliter analyzer cups or disposable spectrophotometer cuvettes serve as reaction vessels for enzymatic reduction of nitrate to nitrite prior to analytical determinations. After the reduction step, analyzer cups are loaded onto CFA, flow injection, or discrete analyzers for simple, rapid, automatic nitrite determinations. In the case of manual determinations, analysts dispense colorimetric reagents into cuvettes containing post-reduction samples, allow time for color to develop, insert cuvettes individually into a spectrophotometer, and record percent transmittance or absorbance in relation to a reagent blank. Data presented here demonstrate equivalent analytical performance of enzymatic reduction NOx methods in these various formats to that of benchmark CFA-CdR NOx methods.

Emissions characteristics of Military Helicopter Engines Fueled with JP-8 and a Fischer-Tropsch Fuel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Corporan, E.; DeWitt, M.; Klingshirn, Christopher D

2010-01-01

The rapid growth in aviation activities and more stringent U.S. Environmental Protection Agency regulations have increased concerns regarding aircraft emissions, due to their harmful health and environmental impacts, especially in the vicinity of airports and military bases. In this study, the gaseous and particulate-matter emissions of two General Electric T701C engines and one T700 engine were evaluated. The T700 series engines power the U.S. Army's Black Hawk and Apache helicopters. The engines were fueled with standard military JP-8 fuel and were tested at three power settings. In addition, one of the T701C engines was operated on a natural-gas-derived Fischer-Tropsch syntheticmore » paraffinic kerosene jet fuel. Test results show that the T701C engine emits significantly lower particulate-matter emissions than the T700 for all conditions tested. Particulate-matter mass emission indices ranged from 0.2-1.4 g/kg fuel for the T700 and 0.2-0.6 g/kg fuel for the T701C. Slightly higher NOx and lower CO emissions were observed for the T701C compared with the T700. Operation of the T701C with the Fischer-Tropsch fuel rendered dramatic reductions in soot emissions relative to operation on JP-8, due primarily to the lack of aromatic compounds in the alternative fuel. The Fischer-Tropsch fuel also produced smaller particles and slight reductions in CO emissions.« less

Estimates of ozone response to various combinations of NO(x) and VOC emission reductions in the eastern United States

NASA Technical Reports Server (NTRS)

Roselle, Shawn J.; Schere, Kenneth L.; Chu, Shao-Hang

1994-01-01

There is increasing recognition that controls on NO(x) emissions may be necessary, in addition to existing and future Volatile Organic Compounds (VOC) controls, for the abatement of ozone (O3) over portions of the United States. This study compares various combinations of anthropogenic NO(x) and VOC emission reductions through a series of model simulations. A total of 6 simulations were performed with the Regional Oxidant Model (ROM) for a 9-day period in July 1988. Each simulation reduced anthropogenic NO(x) and VOC emissions across-the-board by different amounts. Maximum O3 concentrations for the period were compared between the simulations. Comparison of the simulations suggests that: (1) NO(x) controls may be more effective than VOC controls in reducing peak O3 over most of the eastern United States; (2) VOC controls are most effective in urban areas having large sources of emissions; (3) NO(x) controls may increase O3 near large point sources; and (4) the benefit gained from increasing the amount of VOC controls may lessen as the amount of NO(x) control is increased. This paper has been reviewed in accordance with the U.S. Environmental Protection Agency's peer and administrative review policies and approved for presentation and publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

Emissions of NOx, SO2, CO, and HCHO from commercial marine shipping during Texas Air Quality Study (TexAQS) 2006

NASA Astrophysics Data System (ADS)

Williams, E. J.; Lerner, B. M.; Murphy, P. C.; Herndon, S. C.; Zahniser, M. S.

2009-11-01

We report measurements of NOx, SO2, CO, and HCHO mass-based emission factors from more than 200 commercial vessel encounters in the Gulf of Mexico and the Houston-Galveston region of Texas during August and September, 2006. For underway ships, bulk freight carriers have the highest average NOx emissions at ˜87 g NOx (kg fuel)-1, followed by tanker ships at ˜79 g NOx (kg fuel)-1, while container carriers, passenger ships, and tugs all emit an average of about ˜60 g NOx (kg fuel)-1. Emission of NOx from stationary vessels was lower, except for container ships and tugs, and likely reflects use of medium-speed diesel engines. Overall, our mean NOx emission factors are 10-15% lower than published data. Average emission of SO2 was lower for passenger ships and tugs and tows (6-7 g SO2 (kg fuel)-1) than for larger cargo vessels (20-30 g SO2 (kg fuel)-1). Our data for large cargo ships in this region indicate an average residual fuel sulfur content of ˜1.4% which is a factor of two lower than the global average of 2.7%. Emission of CO was low for all categories (7-16 g CO (kg fuel)-1), although our mean overall CO emission factor is about 10% higher than published data. Emission of HCHO was less than 5% that of CO. Despite considerable variability, no functional relationships, such as emissions changes with engine speed or load, could be discerned. Comparison of emission factors from ships to those from other sources suggests ship emissions in this region cannot be ignored.

Promotion effect of H2 on ethanol oxidation and NOx reduction with ethanol over Ag/Al2O3 catalyst.

PubMed

Yu, Yunbo; Li, Yi; Zhang, Xiuli; Deng, Hua; He, Hong; Li, Yuyang

2015-01-06

The catalytic partial oxidation of ethanol and selective catalytic reduction of NOx with ethanol (ethanol-SCR) over Ag/Al2O3 were studied using synchrotron vacuum ultraviolet (VUV) photoionization mass spectrometry (PIMS). The intermediates were identified by PIMS and their photoionization efficiency (PIE) spectra. The results indicate that H2 promotes the partial oxidation of ethanol to acetaldehyde over Ag/Al2O3, while the simultaneously occurring processes of dehydration and dehydrogenation were inhibited. H2 addition favors the formation of ammonia during ethanol-SCR over Ag/Al2O3, the occurrence of which creates an effective pathway for NOx reduction by direct reaction with NH3. Simultaneously, the enhancement of the formation of ammonia benefits its reaction with surface enolic species, resulting in producing -NCO species again, leading to enhancement of ethanol-SCR over Ag/Al2O3 by H2. Using VUV-PIMS, the reactive vinyloxy radical was observed in the gas phase during the NOx reduction by ethanol for the first time, particularly in the presence of H2. Identification of such a reaction occurring in the gas phase may be crucial for understanding the reaction pathway of HC-SCR over Ag/Al2O3.

Engine Performance Test of the 1975 Chrysler - Nissan Model CN633 Diesel Engine

DOT National Transportation Integrated Search

1975-09-01

An engine test of the Chrysler-Nissan Model CN633 diesel engine was performed to determine its steady-state fuel consumption and emissions (HC, CO, NOx) maps. The data acquired are summarized in this report.

Combustion characteristics of an SI engine fueled with biogas fuel

NASA Astrophysics Data System (ADS)

Chen, Lei; Long, Wuqiang; Song, Peng

2017-04-01

An experimental research of the effect of H2 substitution and CO2 dilution on CH4 combustion has been carried out on a spark ignition engine. The results show that H2 addition could improve BMEP, thermal efficiency, CO and THC emissions. NOX emissions increased for higher low heating value (LHV) of H2 than CH4. CO2 dilution could effective reduce NOX emission of H2-CH4 combustion. Although engine performance, thermal efficiency and exhaust get unacceptable under high fuel dilution ratio (F.D.R.) conditions, it could be solved by decreasing F.D.R. and/or increasing hydrogen substitution ratio (H.S.R.).

An assessment of cruise NOx emissions of short-haul commercial flights

NASA Astrophysics Data System (ADS)

Turgut, Enis T.; Usanmaz, Oznur

2017-12-01

Cruise NOx emissions of aircraft are an important input parameter for studies investigating climate change due to their ability to alter the concentrations of certain trace gases, such as ozone, methane, and hydroxyl in the atmosphere, and to induce positive radiative forcing. Therefore, it is of importance to minimize estimation errors on NOx emitted from aircraft engines at high altitude. In this study, the cruise NOx emissions of a frequently-used narrow-bodied aircraft type operating domestic flights in Turkey, are quantified based on numerous actual flight, actual emissions and actual meteorological data. The overall average cruise NOx emissions index is found to be ∼10 g/kg fuel. In addition, newly-developed parameters of the aircraft cruise NOx footprint and NOx intensity are calculated to be 0.5 g/pa-NM and ∼60 g/NM, respectively. Regarding the effects of flight parameters on cruise NOx emissions, while there is a distinct increase in NOx parameters with an increase in aircraft mass, this may differ for altitude. The results reveal that the NOx emissions index tends to increase slightly by 1-2%, particularly above 28,000 ft, whereas NOx intensity decreases at a rate of 2.4-2.7% per 2000 ft of cruise altitude increase.

Ships going slow in reducing their NOx emissions: changes in 2005-2012 ship exhaust inferred from satellite measurements over Europe

NASA Astrophysics Data System (ADS)

Folkert Boersma, K.; Vinken, Geert C. M.; Tournadre, Jean

2015-07-01

We address the lack of temporal information on ship emissions, and report on rapid short-term variations of satellite-derived ship NOx emissions between 2005 and 2012 over European seas. Our inversion is based on OMI observed tropospheric NO2 columns and GEOS-Chem simulations. Average European ship NOx emissions increased by ˜15% from 2005 to 2008. This increase was followed by a reduction of ˜12% in 2009, a direct result of the global economic downturn in 2008-2009, and steady emissions from 2009 to 2012. Observations of ship passages through the Suez Canal and satellite altimeter derived ship densities suggests that ships in the Mediterranean Sea have reduced their speed by more than 30% since 2008. This reduction in ship speed is accompanied by a persistent 45% reduction of average, per ship NOx emission factors. Our results indicate that the practice of ‘slow steaming’, i.e. the lowering of vessel speed to reduce fuel consumption, has indeed been implemented since 2008, and can be detected from space. In spite of the implementation of slow steaming, one in seven of all NOx molecules emitted in Europe in 2012 originated from the shipping sector, up from one in nine in 2005. The growing share of the shipping contributions to the overall European NOx emissions suggests a need for the shipping sector to implement additional measures to reduce pollutant emissions at rates that are achieved by the road transport and energy producing sectors in Europe.

2002 NASA Seal/Secondary Air System Workshop. Volume 1

NASA Technical Reports Server (NTRS)

Steinetz, Bruce M. (Editor); Hendricks, Robert C. (Editor)

2003-01-01

The 2002 NASA Seal/Secondary Air System Workshop covered the following topics: (i) Overview of NASA s perspective of aeronautics and space technology for the 21st century; (ii) Overview of the NASA-sponsored Ultra-Efficient Engine Technology (UEET), Turbine-Based Combined-Cycle (TBCC), and Revolutionary Turbine Accelator (RTA) programs; (iii) Overview of NASA Glenn's seal program aimed at developing advanced seals for NASA's turbomachinery, space propulsion, and reentry vehicle needs; (iv) Reviews of sealing concepts, test results, experimental facilities, and numerical predictions; and (v) Reviews of material development programs relevant to advanced seals development. The NASA UEET and TBCC/RTA program overviews illustrated for the reader the importance of advanced technologies, including seals, in meeting future turbine engine system efficiency and emission goals. For example, the NASA UEET program goals include an 8- to 15-percent reduction in fuel burn, a 15-percent reduction in CO2, a 70-percent reduction in NOx, CO, and unburned hydrocarbons, and a 30-dB noise reduction relative to program baselines. The workshop also covered several programs NASA is funding to investigate advanced reusable space vehicle technologies (X-38) and advanced space ram/scramjet propulsion systems. Seal challenges posed by these advanced systems include high-temperature operation, resiliency at the operating temperature to accommodate sidewall flexing, and durability to last many missions.

Nitrogen Isotope Composition of Thermally Produced NOx from Various Fossil-Fuel Combustion Sources.

PubMed

Walters, Wendell W; Tharp, Bruce D; Fang, Huan; Kozak, Brian J; Michalski, Greg

2015-10-06

The nitrogen stable isotope composition of NOx (δ(15)N-NOx) may be a useful indicator for NOx source partitioning, which would help constrain NOx source contributions in nitrogen deposition studies. However, there is large uncertainty in the δ(15)N-NOx values for anthropogenic sources other than on-road vehicles and coal-fired energy generating units. To this end, this study presents a broad analysis of δ(15)N-NOx from several fossil-fuel combustion sources that includes: airplanes, gasoline-powered vehicles not equipped with a three-way catalytic converter, lawn equipment, utility vehicles, urban buses, semitrucks, residential gas furnaces, and natural-gas-fired power plants. A relatively large range of δ(15)N-NOx values was measured from -28.1‰ to 8.5‰ for individual exhaust/flue samples that generally tended to be negative due to the kinetic isotope effect associated with thermal NOx production. A negative correlation between NOx concentrations and δ(15)N-NOx for fossil-fuel combustion sources equipped with selective catalytic reducers was observed, suggesting that the catalytic reduction of NOx increases δ(15)N-NOx values relative to the NOx produced through fossil-fuel combustion processes. Combining the δ(15)N-NOx measured in this study with previous published values, a δ(15)N-NOx regional and seasonal isoscape was constructed for the contiguous U.S., which demonstrates seasonal and regional importance of various NOx sources.

Effective NOx remediation from a surrogate flue gas using the US NRL Electra electron beam facility

NASA Astrophysics Data System (ADS)

Petrova, Tz. B.; Petrov, G. M.; Wolford, M. F.; Giuliani, J. L.; Ladouceur, H. D.; Hegeler, F.; Myers, M. C.; Sethian, J. D.

2017-02-01

Nitric oxide (NOx) emission is under restrictive federal regulations because of its negative impact on atmosphere, biosphere, and human health. Therefore, its removal has been a subject of extensive research to develop new efficient and cost effective techniques that can be applied on an industrial scale. In this work, we study both experimentally and theoretically an effective removal of NOx pollutants from a surrogate flue gas (SFG) using high power electron beam (e-beam) pulses. SFG is a simulant for exhaust from coal combustion power plants (82% N2, 6% O2, 12% CO2, and ˜100 ppm of NOx). The pulsed electron beam is generated using the United States Naval Research Laboratory Electra facility, which delivers e-beams with energies of ˜500 keV and a power pulse duration of ˜140 ns. During the e-beam irradiation, the energetic electrons generate a non-equilibrium plasma containing chemically active species, which then react with NOx to form harmless substances. A non-equilibrium time-dependent model is developed to describe NOx remediation from SFG. The model combines e-beam deposition rates obtained by solving the electron Boltzmann equation and extensive plasma chemistry modeling, which follows the species on a time scale from sub-nanoseconds to a few seconds. NOx decomposition as a function of electron beam parameters is studied. It is demonstrated experimentally that short (ns) pulses are the most efficient for NOx removal. A sharp reduction of NOx was measured with e-beam power deposition increasing, following the trend predicted by the model, achieving a 20 fold reduction to ˜5 ppm at energy deposition ˜20 J/l.

Effect of K loadings on nitrate formation/decomposition and on NOx storage performance of K-based NOx storage-reduction catalysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Do Heui; Mudiyanselage, Kumudu K.; Szanyi, Janos

2013-10-25

We have investigated nitrate formation and decomposition processes, and measured NOx storage performance on Pt-K2O/Al2O3 catalysts as a function of potassium loading. After NO2 adsorption at room temperature, ionic and bidentate nitrates were observed by fourier transform infra-red (FTIR) spectroscopy. The ratio of the former to the latter species increased with increasing potassium loading up to 10 wt%, and then stayed almost constant with additional K, demonstrating a clear dependence of loading on the morphology of the K species. Although both K2O(10)/Al2O3 and K2O(20)/Al2O3 samples have similar nitrate species after NO2 adsorption, the latter has more thermally stable nitrate speciesmore » as evidenced by FTIR and NO2 temperature programmed desorption (TPD) results. With regard to NOx storage performance, the temperature of maximum NOx uptake (Tmax) is 573 K up to a potassium loading of 10 wt%. As the potassium loading increases from 10 wt% to 20 wt%, Tmax shifted from 573 K to 723 K. Moreover, the amount of NO uptake (38 cm3 NOx/g catal) at Tmax increased more than three times, indicating that efficiency of K in storing NOx is enhanced significantly at higher temperature, in good agreement with the NO2 TPD and FTIR results. Thus, a combination of characterization and NOx storage performance results demonstrates an unexpected effect of potassium loading on nitrate formation and decomposition processes; results important for developing Pt-K2O/Al2O3 for potential applications as high temperature NOx storage-reduction catalysts.« less

Effect of ethanol-gasoline blends on small engine generator energy efficiency and exhaust emission.

PubMed

Lin, Wen-Yinn; Chang, Yuan-Yi; Hsieh, You-Ru

2010-02-01

This study was focused on fuel energy efficiency and pollution analysis of different ratios of ethanol-gasoline blended fuels (E0, E3, E6, and E9) under different loadings. In this research, the experimental system consisted of a small engine generator, a particulate matter measurement system, and an exhaust gas analyzer system. Different fuels, unleaded gasoline, and ethanol-gasoline blends (E0, E3, E6, and E9) were used to study their effects on the exhaust gas emission and were expressed as thermal efficiency of the small engine generator energy efficiency. The results suggested that particle number concentration increased as the engine loading increased; however, it decreased as the ethanol content in the blend increased. While using E6 as fuel, the carbon monoxide (CO) concentration was less than other fuels (E0, E3, and E9) for each engine loading. The average of CO concentration reduction by using E3, E6, and E9 is 42, 86, and 83%, respectively. Using an ethanol-gasoline blend led to a significant reduction in exhaust emissions by approximately 78.7, 97.5, and 89.46% of the mean average values of hydrocarbons (HCs) with E3, E6, and E9 fuels, respectively, for all engine loadings. Using an ethanol-gasoline blend led to a significant reduction in exhaust emissions by approximately 35, 86, and 77% of the mean average values of nitrogen oxides (NOx) with E3, E6, and E9 fuels, respectively, at each engine loading. The E6 fuel gave the best results of the exhaust emissions, and the E9 fuel gave the best results of the particle emissions and engine performance. The thermal efficiency of the small engine generator increased as the ethanol content in the blend increased and as the engine loading increased.

Reducing diesel NOx and PM emissions of diesel buses and trucks.

DOT National Transportation Integrated Search

2008-07-01

The objective of the present investigation was development of a high efficiency : selective catalytic reduction (SCR) system for reducing diesel nitrogen oxides (NOx) and : particulate matters of diesel trucks. The investigation was divided into two ...

EVALUATION OF SIMULTANEOUS SO2/NOX CONTROL TECHNOLOGY

EPA Science Inventory

The report gives results of work concentrating on characterizing three process operational parameters of a technology that combines sorbent injection and selective non-catalytic reduction for simultaneous sulfur dioxide/nitrogen oxide (SO2/NOx) removal from coal-fired industrial ...

City-specific vehicle emission control strategies to achieve stringent emission reduction targets in China's Yangtze River Delta region.

PubMed

Zhang, Shaojun; Wu, Ye; Zhao, Bin; Wu, Xiaomeng; Shu, Jiawei; Hao, Jiming

2017-01-01

The Yangtze River Delta (YRD) region is one of the most prosperous and densely populated regions in China and is facing tremendous pressure to mitigate vehicle emissions and improve air quality. Our assessment has revealed that mitigating vehicle emissions of NOx would be more difficult than reducing the emissions of other major vehicular pollutants (e.g., CO, HC and PM 2.5 ) in the YRD region. Even in Shanghai, where the emission control implemented are more stringent than in Jiangsu and Zhejiang, we observed little to no reduction in NOx emissions from 2000 to 2010. Emission-reduction targets for HC, NOx and PM 2.5 are determined using a response surface modeling tool for better air quality. We design city-specific emission control strategies for three vehicle-populated cities in the YRD region: Shanghai and Nanjing and Wuxi in Jiangsu. Our results indicate that even if stringent emission control consisting of the Euro 6/VI standards, the limitation of vehicle population and usage, and the scrappage of older vehicles is applied, Nanjing and Wuxi will not be able to meet the NOx emissions target by 2020. Therefore, additional control measures are proposed for Nanjing and Wuxi to further mitigate NOx emissions from heavy-duty diesel vehicles. Copyright © 2016. Published by Elsevier B.V.

40 CFR 1043.70 - General recordkeeping and reporting requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... POLLUTION CONTROLS CONTROL OF NOX, SOX, AND PM EMISSIONS FROM MARINE ENGINES AND VESSELS SUBJECT TO THE... operators of non-Party vessels must keep these records as specified in the NOX Technical Code and... operator has fuel receipts (or equivalent records) for the preceding three years showing it operated using...

40 CFR 1043.70 - General recordkeeping and reporting requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... POLLUTION CONTROLS CONTROL OF NOX, SOX, AND PM EMISSIONS FROM MARINE ENGINES AND VESSELS SUBJECT TO THE... operators of non-Party vessels must keep these records as specified in the NOX Technical Code and... operator has fuel receipts (or equivalent records) for the preceding three years showing it operated using...

40 CFR 1043.70 - General recordkeeping and reporting requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... POLLUTION CONTROLS CONTROL OF NOX, SOX, AND PM EMISSIONS FROM MARINE ENGINES AND VESSELS SUBJECT TO THE... operators of non-Party vessels must keep these records as specified in the NOX Technical Code and... operator has fuel receipts (or equivalent records) for the preceding three years showing it operated using...

40 CFR 1043.70 - General recordkeeping and reporting requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... POLLUTION CONTROLS CONTROL OF NOX, SOX, AND PM EMISSIONS FROM MARINE ENGINES AND VESSELS SUBJECT TO THE... operators of non-Party vessels must keep these records as specified in the NOX Technical Code and... operator has fuel receipts (or equivalent records) for the preceding three years showing it operated using...

40 CFR 1043.70 - General recordkeeping and reporting requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... POLLUTION CONTROLS CONTROL OF NOX, SOX, AND PM EMISSIONS FROM MARINE ENGINES AND VESSELS SUBJECT TO THE... operators of non-Party vessels must keep these records as specified in the NOX Technical Code and... operator has fuel receipts (or equivalent records) for the preceding three years showing it operated using...

The effect of incomplete fuel-air mixing on the lean blowout limit, lean stability limit and NO(x) emissions in lean premixed gas turbine combustors

NASA Technical Reports Server (NTRS)

Shih, W.-P.; Lee, J. G.; Santavicca, D. A.

1994-01-01

Gas turbine engines for both land-based and aircraft propulsion applications are facing regulations on NOx emissions which cannot be met with current combustor technology. A number of alternative combustor strategies are being investigated which have the potential capability of achieving ultra-low NOx emissions, including lean premixed combustors, direct injection combustors, rich burn-quick quench-lean burn combustors and catalytic combustors. The research reported in this paper addresses the effect of incomplete fuel-air mixing on the lean limit performance and the NOx emissions characteristics of lean premixed combustors.

Determination of the NOx Loading of an Automotive Lean NOx Trap by Directly Monitoring the Electrical Properties of the Catalyst Material Itself

PubMed Central

Fremerey, Peter; Reiß, Sebastian; Geupel, Andrea; Fischerauer, Gerhard; Moos, Ralf

2011-01-01

Recently, it has been shown that the degree of loading of several types of automotive exhaust aftertreatment devices can be directly monitored in situ and in a contactless way by a microwave-based method. The goal of this study was to clarify whether this method can also be applied to NOx storage and reduction catalysts (lean NOx traps) in order to obtain further knowledge about the reactions occurring in the catalyst and to compare the results with those obtained by wirebound NOx loading sensors. It is shown that both methods are able to detect the different catalyst loading states. However, the sensitivity of the microwave-based method turned out to be small compared to that previously observed for other exhaust aftertreatment devices. This may limit the practical applicability of the microwave-based NOx loading detection in lean NOx traps. PMID:22164074

A comparative study of almond biodiesel-diesel blends for diesel engine in terms of performance and emissions.

PubMed

Abu-Hamdeh, Nidal H; Alnefaie, Khaled A

2015-01-01

This paper investigates the opportunity of using almond oil as a renewable and alternative fuel source. Different fuel blends containing 10, 30, and 50% almond biodiesel (B10, B30, and B50) with diesel fuel (B0) were prepared and the influence of these blends on emissions and some performance parameters under various load conditions were inspected using a diesel engine. Measured engine performance parameters have generally shown a slight increase in exhaust gas temperature and in brake specific fuel consumption and a slight decrease in brake thermal efficiency. Gases investigated were carbon monoxide (CO) and oxides of nitrogen (NOx). Furthermore, the concentration of the total particulate and the unburned fuel emissions in the exhaust gas were tested. A blend of almond biodiesel with diesel fuel gradually reduced the engine CO and total particulate emissions compared to diesel fuel alone. This reduction increased with more almond biodiesel blended into the fuel. Finally, a slight increase in engine NO x using blends of almond biodiesel was measured.

Advanced Natural Gas Reciprocating Engine(s)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pike, Edward

The objective of the Cummins ARES program, in partnership with the US Department of Energy (DOE), is to develop advanced natural gas engine technologies that increase engine system efficiency at lower emissions levels while attaining lower cost of ownership. The goals of the project are to demonstrate engine system achieving 50% Brake Thermal Efficiency (BTE) in three phases, 44%, 47% and 50% (starting baseline efficiency at 36% BTE) and 0.1 g/bhp-hr NOx system out emissions (starting baseline NOx emissions at 2 – 4 g/bhp-hr NOx). Primary path towards above goals include high Brake Mean Effective Pressure (BMEP), improved closed cyclemore » efficiency, increased air handling efficiency and optimized engine subsystems. Cummins has successfully demonstrated each of the phases of this program. All targets have been achieved through application of a combined set of advanced base engine technologies and Waste Heat Recovery from Charge Air and Exhaust streams, optimized and validated on the demonstration engine and other large engines. The following architectures were selected for each Phase: Phase 1: Lean Burn Spark Ignited (SI) Key Technologies: High Efficiency Turbocharging, Higher Efficiency Combustion System. In production on the 60/91L engines. Over 500MW of ARES Phase 1 technology has been sold. Phase 2: Lean Burn Technology with Exhaust Waste Heat Recovery (WHR) System Key Technologies: Advanced Ignition System, Combustion Improvement, Integrated Waste Heat Recovery System. Base engine technologies intended for production within 2 to 3 years Phase 3: Lean Burn Technology with Exhaust and Charge Air Waste Heat Recovery System Key Technologies: Lower Friction, New Cylinder Head Designs, Improved Integrated Waste Heat Recovery System. Intended for production within 5 to 6 years Cummins is committed to the launch of next generation of large advanced NG engines based on ARES technology to be commercialized worldwide.« less

Experimental Assessment of the Emissions Control Potential of a Rich/Quench/Lean Combustor for High Speed Civil Transport Aircraft Engines

NASA Technical Reports Server (NTRS)

Rosfjord, T. J.; Padget, F. C.; Tacina, Robert R. (Technical Monitor)

2001-01-01

In support of Pratt & Whitney efforts to define the Rich burn/Quick mix/Lean burn (RQL) combustor for the High Speed Civil Transport (HSCT) aircraft engine, UTRC conducted a flametube-scale study of the RQL concept. Extensive combustor testing was performed at the Supersonic Cruise (SSC) condition of a HSCT engine cycle, Data obtained from probe traverses near the exit of the mixing section confirmed that the mixing section was the critical component in controlling combustor emissions. Circular-hole configurations, which produced rapidly-, highly-penetrating jets, were most effective in limiting NOx. The spatial profiles of NOx and CO at the mixer exit were not directly interpretable using a simple flow model based on jet penetration, and a greater understanding of the flow and chemical processes in this section are required to optimize it. Neither the rich-combustor equivalence ratio nor its residence time was a direct contributor to the exit NOx. Based on this study, it was also concluded that (1) While NOx formation in both the mixing section and the lean combustor contribute to the overall emission, the NOx formation in the mixing section dominates. The gas composition exiting the rich combustor can be reasonably represented by the equilibrium composition corresponding to the rich combustor operating condition. Negligible NOx exits the rich combustor. (2) At the SSC condition, the oxidation processes occurring in the mixing section consume 99 percent of the CO exiting the rich combustor. Soot formed in the rich combustor is also highly oxidized, with combustor exit SAE Smoke Number <3. (3) Mixing section configurations which demonstrated enhanced emissions control at SSC also performed better at part-power conditions. Data from mixer exit traverses reflected the expected mixing behavior for off-design jet to crossflow momentum-flux ratios. (4) Low power operating conditions require that the RQL combustor operate as a lean-lean combustor to achieve low CO and high efficiency. (5) A RQL combustor can achieve the emissions goal of EINOX = 5 at the Supersonic Cruise operating condition for a HSCT engine.

Experimental Assessment of the Emissions Control Potential of a Rich/Quench/ Lean Combustor for High Speed Civil Transport Aircraft Engines

NASA Technical Reports Server (NTRS)

Tacina, Robert R. (Technical Monitor); Rosfjord, T. J.; Padget, F. C.

2001-01-01

In support of Pratt & Whitney efforts to define the Rich burn/Quick mix/Lean burn (RQL) combustor for the High Speed Civil Transport (HSCT) aircraft engine, UTRC conducted a flametube-scale study of the RQL concept. Extensive combustor testing was performed at the Supersonic Cruise (SSC) condition of an HSCT engine cycle. Data obtained from probe traverses near the exit of the mixing section confirmed that the mixing section was the critical component in controlling combustor emissions. Circular-hole configurations, which produced rapidly-, highly-penetrating jets, were most effective in limiting NO(x). The spatial profiles of NO(x) and CO at the mixer exit were not directly interpretable using a simple flow model based on jet penetration, and a greater understanding of the flow and chemical processes in this section are required to optimize it. Neither the rich-combustor equivalence ratio nor its residence time was a direct contributor to the exit NO(x). Based on this study, it was also concluded that: (1) While NO(x) formation in both the mixing section and the lean combustor contribute to the overall emission, the NOx formation in the mixing section dominates. The gas composition exiting the rich combustor can be reasonably represented by the equilibrium composition corresponding to the rich combustor operating condition. Negligible NO(x) exits the rich combustor. (2) At the SSC condition, the oxidation processes occurring in the mixing section consume 99 percent of the CO exiting the rich combustor. Soot formed in the rich combustor is also highly oxidized, with combustor exit SAE Smoke Number <3. (3) Mixing section configurations which demonstrated enhanced emissions control at SSC also performed better at part-power conditions. Data from mixer exit traverses reflected the expected mixing behavior for off-design jet to crossflow momentum-flux ratios. (4) Low power operating conditions require that the RQL combustor operate as a lean-lean combustor to achieve low CO and high efficiency. (5) An RQL combustor can achieve the emissions goal of EINO(x) = 5 at the Supersonic Cruise operating condition for an HSCT engine.

Simultaneous NOx and Particulate Matter Removal from Diesel Exhaust by Hierarchical Fe-Doped Ce–Zr Oxide

PubMed Central

2017-01-01

Particulate matter and NOx emissions from diesel exhaust remains one of the most pressing environmental problems. We explore the use of hierarchically ordered mixed Fe–Ce–Zr oxides for the simultaneous capture and oxidation of soot and reduction of NOx by ammonia in a single step. The optimized material can effectively trap the model soot particles in its open macroporous structure and oxidize the soot below 400 °C while completely removing NO in the 285–420 °C range. Surface characterization and DFT calculations emphasize the defective nature of Fe-doped ceria. The isolated Fe ions and associated oxygen vacancies catalyze facile NO reduction to N2. A mechanism for the reduction of NO with NH3 on Fe-doped ceria is proposed involving adsorbed O2. Such adsorbed O2 species will also contribute to the oxidation of soot. PMID:28603656

Fuel/air nonuniformity - Effect on nitric oxide emissions

NASA Technical Reports Server (NTRS)

Lyons, V. J.

1981-01-01

An analytical and experimental study was performed to determine the effect of inlet fuel/air profile nonuniformity on NO(x) emissions. The theoretical NO(x) levels were verified in a flame-tube rig at inlet air temperatures of 600, 700, and 800 K, 0.3 MPa rig pressure, 25 m/sec reference velocity, overall equivalence ratio of 0.6 and residence time near 0.002 sec. The theory predicts an increase in NO(x) emissions for increased fuel/air nonuniformity for average equivalence ratios less than 0.7, while for average equivalence ratios near stoichiometric, increasing the nonuniformity will decrease NO(x) emissions. The results can be used to predict the degree of uniformity of fuel/air profiles necessary to achieve NO(x) emissions goals for actual engines that use lean premixed, prevaporized combustion systems.

Effects of biodiesel on continuous regeneration DPF characteristics

NASA Astrophysics Data System (ADS)

Chen, Tao; Xie, Hui; Gao, Guoyou; Wang, Wei; Hui, Chun

2017-06-01

A critical requirement for the implementation of DPF on a modern engine is the determination of Break-even Temperature (BET) which is defined as the temperature at which particulate deposition on the filter is balanced by particulate oxidation on the filter. In order to study the influence of biodiesel on the Regenerating Characteristics of Continuously Regeneration DPF, Bench test were carried out to investigate the BET of a continuously regeneration DPF assembled with a diesel engine fueled with neat diesel and biodiesel. Test results show that at the same engine operation conditions the fuel consumption is higher for biodiesel case, and also the intake air quantity and boost pressure are lower; the BET for the Diesel fuel is about 310 ° while it is about 250 ° for the Biodiesel case. When the engine is at the low torque and low exhaust temperature operation condition, CO conversion rate is extremely low, NO2/NOX ratio is small; with the increase of torque and exhaust temperature, CO conversion and NO2/NOX ratio increased significantly, and the maximum NO2/NOX ratio (about 35%) has been measured at 350 °. In addition, the DPF has better filtration efficiency for biodiesel PM, and the use of biodiesel to engine assembled with DPF has significant benefits.

40 CFR 1065.125 - Engine intake air.

Code of Federal Regulations, 2010 CFR

2010-07-01

... engines with multiple intakes with separate humidity measurements at each intake, use a flow-weighted average humidity for NOX corrections. If individual flows of each intake are not measured, use good engineering judgment to estimate a flow-weighted average humidity. (3) Temperature. Good engineering judgment...

Effect of battery state of charge on fuel use and pollutant emissions of a full hybrid electric light duty vehicle

NASA Astrophysics Data System (ADS)

Duarte, G. O.; Varella, R. A.; Gonçalves, G. A.; Farias, T. L.

2014-01-01

This research work focuses on evaluating the effect of battery state of charge (SOC) in the fuel consumption and gaseous pollutant emissions of a Toyota Prius Full Hybrid Electric Vehicle, using the Vehicle Specific Power Methodology. Information on SOC, speed and engine management was obtained from the OBD interface, with additional data collected from a 5 gas analyzer and GPS receiver with barometric altimeter. Compared with average results, 40-50% battery SOC presented higher fuel consumption (57%), as well as higher CO2 (56%), CO (27%) and NOx (55.6%) emissions. For battery SOC between 50 and 60%, fuel consumption and CO2 were 9.7% higher, CO was 1.6% lower and NOx was 20.7% lower than average. For battery SOC between 60 and 70%, fuel consumption was 3.4% lower, CO2 was 3.6% lower, CO was 6.9% higher and NOx was 24.4% higher than average. For battery SOC between 70 and 80%, fuel consumption was 39.9% lower, CO2 was 38% lower, CO was 33.9% lower and NOx was 61.4% lower than average. The effect of engine OFF periods was analyzed for CO and NOx emissions. For OFF periods higher than 30 s, increases of 63% and 73% respectively were observed.

NOx Emission Reduction and its Effects on Ozone during the 2008 Olympic Games

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Qing; Wang, Yuhang; Zhao, Chun

2011-07-15

We applied a daily-assimilated inversion method to estimate NOx (NO+NO2) emissions for June-September 2007 and 2008 on the basis of the Aura Ozone Monitoring Instrument (OMI) observations of nitrogen dioxide (NO2) and model simulations using the Regional chEmistry and trAnsport Model (REAM). Over urban Beijing, rural Beijing, and the Huabei Plain, OMI column NO2 reductions are approximately 45%, 33%, and 14%, respectively, while the corresponding anthropogenic NOx emission reductions are only 28%, 24%, and 6%, during the full emission control period (July 20 – Sep 20, 2008). The emission reduction began in early July and was in full force bymore » July 20, corresponding to the scheduled implementation of emission controls over Beijing. The emissions did not appear to recover after the emission control period. Meteorological change from summer 2007 to 2008 is the main factor contributing to the column NO2 decreases not accounted for by the emission reduction. Model simulations suggest that the effect of emission reduction on ozone concentrations over Beijing is relatively minor using a standard VOC emission inventory in China. With an adjustment of the model emissions to reflect in situ observations of VOCs in Beijing, the model simulation suggests a larger effect of the emission reduction.« less

Air quality benefits of universal particle filter and NOx controls on diesel trucks

NASA Astrophysics Data System (ADS)

Tao, L.; Mcdonald, B. C.; Harley, R.

2015-12-01

Heavy-duty diesel trucks are a major source of black carbon/particulate matter and nitrogen oxide emissions on urban and regional scales. These emissions are relevant to both air quality and climate change. Since 2010 in the US, new engines are required to be equipped with emission control systems that greatly reduce both PM and NOx emissions, by ~98% relative to 1988 levels. To reduce emissions from the legacy fleet of older trucks that still remain on the road, regulations have been adopted in Califonia to accelerate the replacement of older trucks and thereby reduce associated emissions of PM and NOx. Use of diesel particle filters will be widespread by 2016, and universal use of catalytic converters for NOx control is required by 2023. We assess the air quality consequences of this clean-up effort in Southern California, using the Community Multiscale Air Quality model (CMAQ), and comparing three scenarios: historical (2005), present day (2016), and future year (2023). Emissions from the motor vehicle sector are mapped at high spatial resolution based on traffic count and fuel sales data. NOx emissions from diesel engines in 2023 are expected to decrease by ~80% compared to 2005, while the fraction of NOx emitted as NO2 is expected to increase from 5 to 18%. Air quality model simulations will be analyzed to quantify changes in NO2, black carbon, particulate matter, and ozone, both basin-wide and near hot spots such as ports and major highways.

40 CFR 86.004-30 - Certification.

Code of Federal Regulations, 2011 CFR

2011-07-01

... simulation of such, resulting in an increase of 1.5 times the NMHC+NOX standard or FEL above the NMHC+NOX... simulation of such, resulting in exhaust emissions exceeding 1.5 times the applicable standard or FEL for... catastrophically failed, or an electronic simulation of such. (2)(i) Otto-cycle. An engine misfire condition is...

40 CFR 86.004-30 - Certification.

Code of Federal Regulations, 2014 CFR

2014-07-01

... simulation of such, resulting in an increase of 1.5 times the NMHC+NOX standard or FEL above the NMHC+NOX... simulation of such, resulting in exhaust emissions exceeding 1.5 times the applicable standard or FEL for... catastrophically failed, or an electronic simulation of such. (2)(i) Otto-cycle. An engine misfire condition is...

40 CFR 86.332-79 - Oxides of nitrogen analyzer calibration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Emission Regulations for New Gasoline-Fueled and Diesel-Fueled Heavy-Duty Engines; Gaseous Exhaust Test.... (2) Zero the oxides of nitrogen analyzer. (3) Connect the outlet of the NOX generator (see Figure D79... operating range. (4) Introduce into the NOX generator-analyzer system a span gas with a NO concentration...

40 CFR 86.332-79 - Oxides of nitrogen analyzer calibration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Emission Regulations for New Gasoline-Fueled and Diesel-Fueled Heavy-Duty Engines; Gaseous Exhaust Test.... (2) Zero the oxides of nitrogen analyzer. (3) Connect the outlet of the NOX generator (see Figure D79... operating range. (4) Introduce into the NOX generator-analyzer system a span gas with a NO concentration...

40 CFR 89.207 - Credit calculation.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Trading Provisions § 89.207 Credit calculation. (a) Requirements for calculating NO X credits from Tier 1...) × (Volume) × (AvgPR) × (UL) × (10−6) Where: Std = the applicable Tier 1 NOX nonroad engine emission standard...) of this section, to be applied to Tier 1 NOX credits to be banked or traded for determining...

Trends in on-road vehicle emissions and ambient air quality in Atlanta, Georgia, USA, from the late 1990s through 2009.

PubMed

Vijayaraghavan, Krish; DenBleyker, Allison; Ma, Lan; Lindhjem, Chris; Yarwood, Greg

2014-07-01

On-road vehicle emissions of carbon monoxide (CO), nitrogen oxides (NO(x)), and volatile organic compounds (VOCs) during 1995-2009 in the Atlanta Metropolitan Statistical Area were estimated using the Motor Vehicle Emission Simulator (MOVES) model and data from the National Emissions Inventories and the State of Georgia. Statistically significant downward trends (computed using the nonparametric Theil-Sen method) in annual on-road CO, NO(x), and VOC emissions of 6.1%, 3.3%, and 6.0% per year, respectively, are noted during the 1995-2009 period despite an increase in total vehicle distance traveled. The CO and NO(x) emission trends are correlated with statistically significant downward trends in ambient air concentrations of CO and NO(x) in Atlanta ranging from 8.0% to 11.8% per year and from 5.8% to 8.7% per year, respectively, during similar time periods. Weather-adjusted summertime ozone concentrations in Atlanta exhibited a statistically significant declining trend of 2.3% per year during 2001-2009. Although this trend coexists with the declining trends in on-road NO(x), VOC, and CO emissions, identifying the cause of the downward trend in ozone is complicated by reductions in multiple precursors from different source sectors. Implications: Large reductions in on-road vehicle emissions of CO and NO(x) in Atlanta from the late 1990s to 2009, despite an increase in total vehicle distance traveled, contributed to a significant improvement in air quality through decreases in ambient air concentrations of CO and NO(x) during this time period. Emissions reductions in motor vehicles and other source sectors resulted in these improvements and the observed declining trend in ozone concentrations over the past decade. Although these historical trends cannot be extrapolated to the future because pollutant concentration contributions due to on-road vehicle emissions will likely become an increasingly smaller fraction of the atmospheric total, they provide an indication of the benefits of past control measures.

Selective catalytic reduction system and process for treating NOx emissions using a palladium and rhodium or ruthenium catalyst

DOEpatents

Sobolevskiy, Anatoly [Orlando, FL; Rossin, Joseph A [Columbus, OH; Knapke, Michael J [Columbus, OH

2011-07-12

A process for the catalytic reduction of nitrogen oxides (NOx) in a gas stream (29) in the presence of H.sub.2 is provided. The process comprises contacting the gas stream with a catalyst system (38) comprising zirconia-silica washcoat particles (41), a pre-sulfated zirconia binder (44), and a catalyst combination (40) comprising palladium and at least one of rhodium, ruthenium, or a mixture of ruthenium and rhodium.

Atmospheric pollution reduction effect and regional predicament: An empirical analysis based on the Chinese provincial NOx emissions.

PubMed

Ding, Lei; Liu, Chao; Chen, Kunlun; Huang, Yalin; Diao, Beidi

2017-07-01

Atmospheric pollution emissions have become a matter of public concern in recent years. However, most of the existing researches on NOx pollution are from the natural science and technology perspective, few studies have been conducted from an economic point, and regional differences have not been given adequate attention. This paper adopts provincial panel data from 2006 to 2013 and the LMDI model to analyze the key driving factors and regional dilemmas of NOx emissions. The results show that significant regional disparities still exit on NO x emissions and its reduction effect 27 provinces didn't accomplish their corresponding reduction targets. Economic development factor is the dominating driving factor of NO x emissions during the study period, while energy efficiency and technology improvement factors offset total NO x emissions in the majority of provinces. In addition, the industrial structure factor plays a more significant role in reducing the NO x emissions after 2011. Therefore, the government should consider all these factors as well as regional heterogeneity in developing appropriate pollution mitigating policies. It's necessary to change NOx emissions control attitude from original key areas control to divided-zone control, not only attaches great importance to the reduction of the original key areas, but also emphasizes the new potential hotspots with high NO x emissions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effectiveness of selective catalytic reduction systems on reducing gaseous emissions from an engine using diesel and biodiesel blends.

PubMed

Borillo, Guilherme C; Tadano, Yara S; Godoi, Ana F L; Santana, Simone S M; Weronka, Fernando M; Penteado Neto, Renato A; Rempel, Dennis; Yamamoto, Carlos I; Potgieter-Vermaak, Sanja; Potgieter, Johannes H; Godoi, Ricardo H M

2015-03-03

The aim of this investigation was to quantify organic and inorganic gas emissions from a four-cylinder diesel engine equipped with a urea selective catalytic reduction (SCR) system. Using a bench dynamometer, the emissions from the following mixtures were evaluated using a Fourier transform infrared (FTIR) spectrometer: low-sulfur diesel (LSD), ultralow-sulfur diesel (ULSD), and a blend of 20% soybean biodiesel and 80% ULSD (B20). For all studied fuels, the use of the SCR system yielded statistically significant (p < 0.05) lower NOx emissions. In the case of the LSD and ULSD fuels, the SCR system also significantly reduced emissions of compounds with high photochemical ozone creation potential, such as formaldehyde. However, for all tested fuels, the SCR system produced significantly (p < 0.05) higher emissions of N2O. In the case of LSD, the NH3 emissions were elevated, and in the case of ULSD and B20 fuels, the non-methane hydrocarbon (NMHC) and total hydrocarbon of diesel (HCD) emissions were significantly higher.

Diesel reformulation using bio-derived propanol to control toxic emissions from a light-duty agricultural diesel engine.

PubMed

Thillainayagam, Muthukkumar; Venkatesan, Krishnamoorthy; Dipak, Rana; Subramani, Saravanan; Sethuramasamyraja, Balaji; Babu, Rajesh Kumar

2017-07-01

In the Indian agricultural sector, millions of diesel-driven pump-sets were used for irrigation purposes. These engines produce carcinogenic diesel particulates, toxic nitrogen oxides (NOx), and carbon monoxide (CO) emissions which threaten the livelihood of large population of farmers in India. The present study investigates the use of n-propanol, a less-explored high carbon bio-alcohol that can be produced by sustainable pathways from industrial and crop wastes that has an attractive opportunity for powering stationary diesel engines meant for irrigation and rural electrification. This study evaluates the use of n-propanol addition in fossil diesel by up to 30% by vol. and concurrently reports the effects of exhaust gas recirculation (EGR) on emissions of an agricultural DI diesel engine. Three blends PR10, PR20, and PR30 were prepared by mixing 10, 20, and 30% by vol. of n-propanol with fossil diesel. Results when compared to baseline diesel case indicated that smoke density reduced with increasing n-propanol fraction in the blends. PR10, PR20, and PR30 reduced smoke density by 13.33, 33.33, and 60%, respectively. NOx emissions increased with increasing n-propanol fraction in the blends. Later, three EGR rates (10, 20, and 30%) were employed. At any particular EGR rate, smoke density remained lower with increasing n-propanol content in the blends under increasing EGR rates. NOx reduced gradually with EGR. At 30% EGR, the blends PR10, PR20, and PR30 reduced NOx emissions by 43.04, 37.98, and 34.86%, respectively when compared to baseline diesel. CO emissions remained low but hydrocarbon (HC) emissions were high for n-propanol/diesel blends under EGR. Study confirmed that n-propanol could be used by up to 30% by vol. with diesel and the blends delivered lower soot density, NOx, and CO emissions under EGR.

Air emissions due to wind and solar power.

PubMed

Katzenstein, Warren; Apt, Jay

2009-01-15

Renewables portfolio standards (RPS) encourage large-scale deployment of wind and solar electric power. Their power output varies rapidly, even when several sites are added together. In many locations, natural gas generators are the lowest cost resource available to compensate for this variability, and must ramp up and down quickly to keep the grid stable, affecting their emissions of NOx and CO2. We model a wind or solar photovoltaic plus gas system using measured 1-min time-resolved emissions and heat rate data from two types of natural gas generators, and power data from four wind plants and one solar plant. Over a wide range of renewable penetration, we find CO2 emissions achieve approximately 80% of the emissions reductions expected if the power fluctuations caused no additional emissions. Using steam injection, gas generators achieve only 30-50% of expected NOx emissions reductions, and with dry control NOx emissions increase substantially. We quantify the interaction between state RPSs and NOx constraints, finding that states with substantial RPSs could see significant upward pressure on NOx permit prices, if the gas turbines we modeled are representative of the plants used to mitigate wind and solar power variability.

40 CFR 86.004-15 - NOX plus NMHC and particulate averaging, trading, and banking for heavy-duty engines.

Code of Federal Regulations, 2013 CFR

2013-07-01

... all diesel-cycle engine families within the same primary service class is allowed. (ii) Urban buses... averaging set from all other heavy-duty engines. Averaging and trading between diesel cycle bus engine... heavy-duty engines, the equivalent mileage is 6.3 miles. For diesel heavy-duty engines, the equivalent...

40 CFR 86.004-15 - NOX plus NMHC and particulate averaging, trading, and banking for heavy-duty engines.

Code of Federal Regulations, 2014 CFR

2014-07-01

... all diesel-cycle engine families within the same primary service class is allowed. (ii) Urban buses... averaging set from all other heavy-duty engines. Averaging and trading between diesel cycle bus engine... heavy-duty engines, the equivalent mileage is 6.3 miles. For diesel heavy-duty engines, the equivalent...

Regulated and non-regulated emissions from in-use diesel-electric switching locomotives.

PubMed

Sawant, Aniket A; Nigam, Abhilash; Miller, J Wayne; Johnson, Kent C; Cocker, David R

2007-09-01

Diesel-electric locomotives are vital to the operation of freight railroads in the United States, and emissions from this source category have generated interest in recent years. They are also gaining attention as an important emission source under the larger set of nonroad sources, both from a regulated emissions and health effects standpoint. The present work analyzes regulated (NOx, PM, THC, CO) and non-regulated emissions from three in-use diesel-electric switching locomotives using standardized sampling and analytical techniques. The engines tested in this work were from 1950, 1960, and 1970 and showed a range of NOx and PM emissions. In general, non-regulated gaseous emissions showed a sharp increase as engines shifted from non-idle to idle operating modes. This is interesting from an emissions perspective since activity data shows that these locomotives spend around 60% of their time idling. In terms of polycyclicaromatic hydrocarbon (PAH) contributions, the dominance of naphthalene and its derivatives over the total PAH emissions was apparent, similar to observations for on-road diesel tractors. Among nonnaphthalenic species, itwas observed that lower molecular weight PAHs and n-alkanes dominated their respective compound classes. Regulated emissions from a newer technology engine used in a back-up generator (BUG) application were also compared againstthe present engines; it was determined that use of the newer engine may lower NOx and PM emissions by up to 30%. Another area of interest to regulators is better estimation of the marine engine inventory for port operations. Toward that end, a comparison of emissions from these engines with engine manufacturer data and the newer technology BUG engine was also performed for a marine duty cycle, another application where these engines are used typically with little modifications.

Development and applications of various optimization algorithms for diesel engine combustion and emissions optimization

NASA Astrophysics Data System (ADS)

Ogren, Ryan M.

For this work, Hybrid PSO-GA and Artificial Bee Colony Optimization (ABC) algorithms are applied to the optimization of experimental diesel engine performance, to meet Environmental Protection Agency, off-road, diesel engine standards. This work is the first to apply ABC optimization to experimental engine testing. All trials were conducted at partial load on a four-cylinder, turbocharged, John Deere engine using neat-Biodiesel for PSO-GA and regular pump diesel for ABC. Key variables were altered throughout the experiments, including, fuel pressure, intake gas temperature, exhaust gas recirculation flow, fuel injection quantity for two injections, pilot injection timing and main injection timing. Both forms of optimization proved effective for optimizing engine operation. The PSO-GA hybrid was able to find a superior solution to that of ABC within fewer engine runs. Both solutions call for high exhaust gas recirculation to reduce oxide of nitrogen (NOx) emissions while also moving pilot and main fuel injections to near top dead center for improved tradeoffs between NOx and particulate matter.

REBURNING THERMAL AND CHEMICAL PROCESSES IN A TWO-DIMENSIONAL PILOT-SCALE SYSTEM

EPA Science Inventory

The paper describes an experimental investigation of the thermal and chemical processes influencing NOx reduction by natural gas reburning in a two-dimensional pilot-scale combustion system. Reburning effectiveness for initial NOx levels of 50-500 ppm and reburn stoichiometric ra...

MOVES2014: Heavy-duty Vehicle Emissions Report

EPA Science Inventory

This report updates MOVES methods for evaluating current HD diesel NOx emission rates based on comparisons to independent data from EPA’s IUVP and Houston drayage programs. The report also details methods/assumptions made for HD gasoline HC, CO and NOx emission rates using reduct...

Complementation of mitochondrial electron transport chain by manipulation of the NAD+/NADH ratio.

PubMed

Titov, Denis V; Cracan, Valentin; Goodman, Russell P; Peng, Jun; Grabarek, Zenon; Mootha, Vamsi K

2016-04-08

A decline in electron transport chain (ETC) activity is associated with many human diseases. Although diminished mitochondrial adenosine triphosphate production is recognized as a source of pathology, the contribution of the associated reduction in the ratio of the amount of oxidized nicotinamide adenine dinucleotide (NAD(+)) to that of its reduced form (NADH) is less clear. We used a water-forming NADH oxidase from Lactobacillus brevis (LbNOX) as a genetic tool for inducing a compartment-specific increase of the NAD(+)/NADH ratio in human cells. We used LbNOX to demonstrate the dependence of key metabolic fluxes, gluconeogenesis, and signaling on the cytosolic or mitochondrial NAD(+)/NADH ratios. Expression of LbNOX in the cytosol or mitochondria ameliorated proliferative and metabolic defects caused by an impaired ETC. The results underscore the role of reductive stress in mitochondrial pathogenesis and demonstrate the utility of targeted LbNOX for direct, compartment-specific manipulation of redox state. Copyright © 2016, American Association for the Advancement of Science.

A computational investigation of diesel and biodiesel combustion and NOx formation in a light-duty compression ignition engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Zihan; Srinivasan, Kalyan K.; Krishnan, Sundar R.

Diesel and biodiesel combustion in a multi-cylinder light duty diesel engine were simulated during a closed cycle (from IVC to EVO), using a commercial computational fluid dynamics (CFD) code, CONVERGE, coupled with detailed chemical kinetics. The computational domain was constructed based on engine geometry and compression ratio measurements. A skeletal n-heptane-based diesel mechanism developed by researchers at Chalmers University of Technology and a reduced biodiesel mechanism derived and validated by Luo and co-workers were applied to model the combustion chemistry. The biodiesel mechanism contains 89 species and 364 reactions and uses methyl decanoate, methyl-9- decenoate, and n-heptane as the surrogatemore » fuel mixture. The Kelvin-Helmholtz and Rayleigh-Taylor (KH-RT) spray breakup model for diesel and biodiesel was calibrated to account for the differences in physical properties of the fuels which result in variations in atomization and spray development characteristics. The simulations were able to capture the experimentally observed pressure and apparent heat release rate trends for both the fuels over a range of engine loads (BMEPs from 2.5 to 10 bar) and fuel injection timings (from 0° BTDC to 10° BTDC), thus validating the overall modeling approach as well as the chemical kinetic models of diesel and biodiesel surrogates. Moreover, quantitative NOx predictions for diesel combustion and qualitative NOx predictions for biodiesel combustion were obtained with the CFD simulations and the in-cylinder temperature trends were correlated to the NOx trends.« less

Neovascularization in an arterio-venous loop-containing tissue engineering chamber: role of NADPH oxidase

PubMed Central

Jiang, F; Zhang, G; Hashimoto, I; Kumar, B S; Bortolotto, S; Morrison, W A; Dusting, G J

2008-01-01

Using an in vivo arterio-venous loop-containing tissue-engineering chamber, we have created a variety of vascularized tissue blocks, including functional myocardium. The viability of the transplanted cells is limited by the rate of neovascularization in the chamber. A Nox2-containing nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is thought to have a critical role in ischaemic angiogenesis. In this study we investigated whether NADPH oxidase is involved in the neovascularization process in the tissue-engineering chamber. New blood vessels originating from the venous and the arterial ends of the loop could be identified after 3 days, and the vessel density (by lectin staining) peaked after 7 days and was maintained for at least 14 days. This was accompanied by granulation tissue formation and concomitant increase in the mRNA level of Nox4 NADPH oxidase. Although the total level of Nox2 mRNA in the chamber tissue decreased from day 3 to day 7, immunohistochemistry identified a strong expression of Nox2 in the endothelial cells of the new vessels. In human microvascular endothelial cells, the NADPH oxidase inhibitor apocynin reduced NADPH oxidase activity and inhibited the angiogenic responses in vitro. Local treatment with the NADPH oxidase inhibitors apocynin or gp91ds-tat peptide significantly suppressed the vessel growth in the chamber. In conclusion, NADPH oxidase-dependent redox signalling is important for neovascularization in this novel tissue-engineering chamber in vivo, and boosting this signalling might be a new approach to extending vascularization and tissue growth. PMID:19012731

Lightning and anthropogenic NOx sources over the U.S. and the western North Atlantic Ocean: Impact on tropospheric O3 from space-borne observations

NASA Astrophysics Data System (ADS)

Choi, Y.; Eldering, A.; Osterman, G.; Wang, Y.; Cunnold, D.; Yang, Q.; Bucsela, E.; Pickering, K.

2008-12-01

We use the Regional chEmical trAnsport Model (REAM) to analyze the contributions of lightning and anthropogenic NOx on ozone concentrations over the U.S. and the western North Atlantic Ocean from June to August 2005. Tropospheric NO2 columns from OMI, tropospheric O3 columns derived from OMI and MLS measurements, and vertical O3 profiles from TES over the region are used in the analysis. With a 50% reduction in the industrial and electrical power generation NOx emissions in the 23 eastern states over the U.S. from 1999 EPA NEI and a parameterization of lightning-produced NOx based on concurrent NLDN, CAPE, and cloud mass flux data, REAM generally captures the spatial distribution of lightning flash rates and OMI NO2 and OMI-MLS O3 column enhancements with high correlation coefficients (0.6-0.9). The model results show that over the U.S., the contribution of surface NOx emissions to summertime tropospheric O3 declines from 47% to 41% due to the reduced emissions. The contribution of surface NOx emissions becomes similar to that of stratospheric transport over the U.S., with the additional being the dramatic reduction in the relative impact of fossil-fuel NOx emissions over continental outflow regions. In the convective outflow regions over the Gulf of Mexico and the western North Atlantic, the contribution of lightning NOx production on tropospheric O3 in the summer is larger than that of anthropogenic NOx emissions with mean differences of 5% to 25%. The impact of NOx produced by lightning is becoming larger as fossil-fuel combustion NOx emissions decrease. After the onset of the North American monsoon, lightning-derived upper tropospheric O3 enhancements in July and August are shown over the convective outflow regions from REAM simulated and TES measured O3 vertical profiles. This result suggests that TES measurements have a potential to constrain lightning-derived tropospheric O3 enhancements, which may play a critical role in controlling climate.

Impact of passenger car NOx emissions and NO2 fractions on urban NO2 pollution - Scenario analysis for the city of Antwerp, Belgium

NASA Astrophysics Data System (ADS)

Degraeuwe, Bart; Thunis, Philippe; Clappier, Alain; Weiss, Martin; Lefebvre, Wouter; Janssen, Stijn; Vranckx, Stijn

2016-02-01

The annual NO2 concentrations in many European cities exceed the established air quality standard. This situation is mainly caused by Diesel cars whose NOx emissions are higher on the road than during type approval in the laboratory. Moreover, the fraction of NO2 in the NOx emissions of modern diesel cars appears to have increased as compared to previous models. In this paper, we assess 1) to which level the distance-specific NOx emissions of Diesel cars should be reduced to meet established air quality standards and 2) if it would be useful to introduce a complementary NO2 emissions limit. We develop a NO2 pollution model that accounts in an analysis of 9 emission scenarios for changes in both, the urban background NO2 concentrations and the local NO2 emissions at street level. We apply this model to the city of Antwerp, Belgium. The results suggest that a reduction in NOx emissions decreases the regional and urban NO2 background concentration; high NO2 fractions increase the ambient NO2 concentrations only in close spatial proximity to the emission source. In a busy access road to the city centre, the average NO2 concentration can be reduced by 23% if Diesel cars emitted 0.35 g NOx/km instead of the current 0.62 g NOx/km. Reductions of 45% are possible if the NOX emissions of Diesel cars decreased to the level of gasoline cars (0.03 g NOx/km). Our findings suggest that the Real-Driving Emissions (RDE) test procedure can solve the problem of NO2 exceedances in cities if it reduced the on-road NOx emissions of diesel cars to the permissible limit of 0.08 g/km. The implementation of a complementary NO2 emissions limit may then become superfluous. If Diesel cars continue to exceed by several factors their NOx emissions limit on the road, a shift of the vehicle fleet to gasoline cars may be necessary to solve persisting air quality problems.

40 CFR 91.208 - Certification.

Code of Federal Regulations, 2010 CFR

2010-07-01

... EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Averaging, Banking, and Trading Provisions § 91.208... engines for which certification is requested will not, to the best of the manufacturer's belief, cause the...'s engine families. (2) Declare an FEL for each engine family for HC plus NOX. The FEL must have the...

Discovery of Nigri/nox and Panto/pox site-specific recombinase systems facilitates advanced genome engineering.

PubMed

Karimova, Madina; Splith, Victoria; Karpinski, Janet; Pisabarro, M Teresa; Buchholz, Frank

2016-07-22

Precise genome engineering is instrumental for biomedical research and holds great promise for future therapeutic applications. Site-specific recombinases (SSRs) are valuable tools for genome engineering due to their exceptional ability to mediate precise excision, integration and inversion of genomic DNA in living systems. The ever-increasing complexity of genome manipulations and the desire to understand the DNA-binding specificity of these enzymes are driving efforts to identify novel SSR systems with unique properties. Here, we describe two novel tyrosine site-specific recombination systems designated Nigri/nox and Panto/pox. Nigri originates from Vibrio nigripulchritudo (plasmid VIBNI_pA) and recombines its target site nox with high efficiency and high target-site selectivity, without recombining target sites of the well established SSRs Cre, Dre, Vika and VCre. Panto, derived from Pantoea sp. aB, is less specific and in addition to its native target site, pox also recombines the target site for Dre recombinase, called rox. This relaxed specificity allowed the identification of residues that are involved in target site selectivity, thereby advancing our understanding of how SSRs recognize their respective DNA targets.

NADPH Oxidase-1 Plays a Key Role in Keratinocyte Responses to UV Radiation and UVB-Induced Skin Carcinogenesis.

PubMed

Raad, Houssam; Serrano-Sanchez, Martin; Harfouche, Ghida; Mahfouf, Walid; Bortolotto, Doriane; Bergeron, Vanessa; Kasraian, Zeinab; Dousset, Lea; Hosseini, Mohsen; Taieb, Alain; Rezvani, Hamid Reza

2017-06-01

The nicotinamide adenine dinucleotide phosphate oxidase (NOX) family enzymes are involved in several physiological functions. However, their roles in keratinocyte responses to UV radiation have not been clearly elucidated. This study shows that, among other NOX family members, UVB irradiation results in a biphasic activation of NOX1 that plays a critical role in defining keratinocyte fate through the modulation of the DNA damage response network. Indeed, suppression of both bursts of UVB-induced NOX1 activation by using a specific peptide inhibitor of NOX1 (InhNOX1) is associated with increased nucleotide excision repair efficiency and reduction of apoptosis, which is finally translated into decreased photocarcinogenesis. On the contrary, when only the second peak of UVB-induced NOX1 activation is blocked, both nucleotide excision repair efficiency and apoptosis are decreased. Our results show that inhibition of NOX1 activation could be a promising target for the prevention and treatment of UVB-induced skin cancer in nucleotide excision repair-proficient and -deficient patients. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Engine Performance Test of the Honda CVCC

DOT National Transportation Integrated Search

1975-09-01

This report presents the data which were obtained from a test of a prototype Honda CVCC, 90.8-cubic-inch, 4-cylinder engine. The data included are sufficient to establish the steady-state engine maps for fuel consumption and emissions (HC, CO, NOx) o...

40 CFR 94.12 - Interim provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... differences in testing will not affect NOX emission rates. (g) Flexibility for engines over 560kW... EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES General Provisions for Emission Regulations for Compression-Ignition Marine Engines § 94.12 Interim provisions. This section contains provisions that apply...

40 CFR 94.12 - Interim provisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... differences in testing will not affect NOX emission rates. (g) Flexibility for engines over 560kW...) CONTROL OF EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES General Provisions for Emission Regulations for Compression-Ignition Marine Engines § 94.12 Interim provisions. This section contains provisions...

40 CFR 94.12 - Interim provisions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... differences in testing will not affect NOX emission rates. (g) Flexibility for engines over 560kW...) CONTROL OF EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES General Provisions for Emission Regulations for Compression-Ignition Marine Engines § 94.12 Interim provisions. This section contains provisions...

40 CFR 94.12 - Interim provisions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... differences in testing will not affect NOX emission rates. (g) Flexibility for engines over 560kW...) CONTROL OF EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES General Provisions for Emission Regulations for Compression-Ignition Marine Engines § 94.12 Interim provisions. This section contains provisions...

40 CFR 94.12 - Interim provisions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... differences in testing will not affect NOX emission rates. (g) Flexibility for engines over 560kW...) CONTROL OF EMISSIONS FROM MARINE COMPRESSION-IGNITION ENGINES General Provisions for Emission Regulations for Compression-Ignition Marine Engines § 94.12 Interim provisions. This section contains provisions...

Mid-IR fiber optic sensors for internal combustion engines

NASA Astrophysics Data System (ADS)

Hall, Matthew J.

1999-12-01

Environmental regulations are driving development of cleaner spark ignition, diesel, and gas turbine engines. Emissions of unburned hydrocarbons, NOx, and CO can be affected by the characteristics of the mixing of the fuel with air in the engine, and by the amount of exhaust gas recirculated to the engine intake. Fiber optic sensors have been developed that can measure the local fuel concentration in the combustion chamber of a spark ignition engine near the spark plug. The sensors detect the absorption of 3.4 micrometer radiation corresponding to the strongest absorption band common to all hydrocarbons. The sensors have been applied to both liquid and gaseous hydrocarbon fuels, and liquid fuels injected directly into the engine combustion chamber. The sensors use white light sources and are designed to detect the absorption throughout the entire band minimizing calibration problems associated with pressure and temperature broadening. Other sensors can detect the concentration of CO2 in the engine intake manifold providing time-resolved measurement of exhaust gas recirculation (EGR). Proper EGR levels are critical for achieving low engine-out emissions of NOx while maintaining acceptable engine performance.

The Sensitivity of U.S. Surface Ozone Formation to NOx, and VOCs as Viewed from Space

NASA Technical Reports Server (NTRS)

Duncan, Bryan N.; Yoshida, Yasuko; Sillman, Sanford; Retscher, Christian; Pickering, Kenneth E.; Martin, Randall V.; Celarier, Edward A.

2009-01-01

We investigated variations in the sensitivity of surface ozone formation in summer to precursor species concentrations of volatile organic compounds (VOCs) and nitrogen oxides (NO(x)) as inferred from the ratio of tropospheric columns of formaldehyde and nitrogen dioxide from the Aura Ozone Monitoring Instrument (OMI). The data indicate that ozone formation became: 1. more sensitive to NO(x) over most of the U.S, from 2005 to 2007 because of substantial decreases in NO(x) emissions primarily from stationary sources, and 2. more sensitive to NO(x) with increasing temperature, in part because emissions of highly reactive, biogenic isoprene increase with temperature, thus increasing the total VOC reactivity. Based on our interpretation of the data, current strategies implemented to reduce unhealthy levels of surface ozone should focus more on reducing NO(x) emissions, except in some downtown areas which have historically benefited from reductions in VOC emissions.

RETROFIT COSTS FOR SO2 AND NOX CONTROL OPTIONS AT 200 COAL-FIRED PLANTS, VOLUME I - INTRODUCTION AND METHODOLOGY

EPA Science Inventory

The report gives results of a study, the objective of which was to significantly improve engineering cost estimates currently being used to evaluate the economic effects of applying SO2 and NOx controls at 200 large SO2-emitting coal-fired utility plants. To accomplish the object...

NOx formation in combustion of gaseous fuel in ejection burner

NASA Astrophysics Data System (ADS)

Rimár, Miroslav; Kulikov, Andrii

2016-06-01

The aim of this work is to prepare model for researching of the formation in combustion of gaseous fuels. NOx formation is one of the main ecological problems nowadays as nitrogen oxides is one of main reasons of acid rains. The ANSYS model was designed according to the calculation to provide full combustion and good mixing of the fuel and air. The current model is appropriate to research NOx formation and the influence of the different principles of NOx reduction method. Applying of designed model should spare both time of calculations and research and also money as you do not need to measure the burner characteristics.

40 CFR 63.6675 - What definitions apply to this subpart?

Code of Federal Regulations, 2010 CFR

2010-07-01

... nitrogen oxides (NOX) control device for rich burn engines that, in a two-step reaction, promotes the... reciprocating internal combustion engine which uses reciprocating motion to convert heat energy into mechanical...

40 CFR 1042.104 - Exhaust emission standards for Category 3 engines.

Code of Federal Regulations, 2013 CFR

2013-07-01

... for other testing. (2) NOX standards apply based on the engine's model year and maximum in-use engine... Engines (g/kW-hr) Emission standards Model year Maximum in-use engine speed Less than130 RPM 130-2000RPM a... standards apply as specified in 40 CFR part 94 for engines originally manufactured in model years 2004...

40 CFR 1042.104 - Exhaust emission standards for Category 3 engines.

Code of Federal Regulations, 2014 CFR

2014-07-01

... for other testing. (2) NOX standards apply based on the engine's model year and maximum in-use engine... Engines (g/kW-hr) Emission standards Model year Maximum in-use engine speed Less than130 RPM 130-2000RPM a... standards apply as specified in 40 CFR part 94 for engines originally manufactured in model years 2004...

Generation and Reduction of NOx on Air-Fed Ozonizers

NASA Astrophysics Data System (ADS)

Ehara, Yoshiyasu; Amemiya, Yusuke; Yamamoto, Toshiaki

A generation and reduction of NOx on air-fed ozonizers using a ferroelectric packed bed reactor have been experimentally investigated. The reactors packed with CaTiO3, SrTiO3 and BaTiO3 pellets are examined for ozone generation. An ac voltage is applied to the reactor to generate partial discharge. Ozone concentration and the different nitrogen oxides at downstream of the packed bed reactor were measured with UV absorption ozone monitor and a Fourier transform infrared spectroscope respectively. The dielectric constant of packed ferroelectric pellets influences the discharge characteristic, ozone and NOx generations are varied by the dielectric constant value. Focusing on a discharge pulse current and maximum discharge magnitude, the ferroelectric packed bed plasma reactors have been evaluated on nitrogen oxide and ozone generated concentrations.

14 CFR 34.23 - Exhaust Emission Standards for Engines Manufactured on and after July 18, 2012.

Code of Federal Regulations, 2014 CFR

2014-01-01

... output less than 26.7 kN (6,000 lb) manufactured on and after July 18, 2012: SN = 83.6(rO) −0.274 or 50.0... Engines Class Rated pressure ratio—rPR Rated output rO(kN) NOX (g/kN) TF, T3, T8 rPR ≤ 30 26.7 89.0 16.72...) NOX (g/kN) CO(g/kN) TSS All 36 + 2.42 (rPR) 4,550 (rPR) −1.03 1 rO is the rated output with...

40 CFR 75.4 - Compliance dates.

Code of Federal Regulations, 2010 CFR

2010-07-01

... volumetric flow rate required under this part (or under the applicable State or Federal mass emissions... applicable on the deadlines specified in the applicable State or federal NOX mass emission reduction program... required by this part for monitoring SO2, NOX, CO2, opacity, moisture and volumetric flow are installed and...

40 CFR 60.44b - Standard for nitrogen oxides (NOX).

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standard for nitrogen oxides (NOX). 60.44b Section 60.44b Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... technological system of emission reduction applied when demonstrating compliance under paragraph (f)(1)(i) of...

40 CFR 60.44b - Standard for nitrogen oxides (NOX).

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standard for nitrogen oxides (NOX). 60.44b Section 60.44b Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... technological system of emission reduction applied when demonstrating compliance under paragraph (f)(1)(i) of...

40 CFR 60.44b - Standard for nitrogen oxides (NOX).

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for nitrogen oxides (NOX). 60.44b Section 60.44b Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... technological system of emission reduction applied when demonstrating compliance under paragraph (f)(1)(i) of...

40 CFR 60.44b - Standard for nitrogen oxides (NOX).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for nitrogen oxides (NOX). 60.44b Section 60.44b Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... technological system of emission reduction applied when demonstrating compliance under paragraph (f)(1)(i) of...

40 CFR 60.44b - Standard for nitrogen oxides (NOX).

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standard for nitrogen oxides (NOX). 60.44b Section 60.44b Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... technological system of emission reduction applied when demonstrating compliance under paragraph (f)(1)(i) of...

40 CFR 89.203 - General provisions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... credits to offset the difference between the emission standards and the FEL for such engine families will...) CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES Averaging, Banking, and.... NMHC+NOX. and PM emissions from eligible nonroad engines are described in this subpart. Participation...

40 CFR 89.203 - General provisions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... credits to offset the difference between the emission standards and the FEL for such engine families will...) CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES Averaging, Banking, and.... NMHC+NOX. and PM emissions from eligible nonroad engines are described in this subpart. Participation...

40 CFR 89.203 - General provisions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... credits to offset the difference between the emission standards and the FEL for such engine families will...) CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES Averaging, Banking, and.... NMHC+NOX. and PM emissions from eligible nonroad engines are described in this subpart. Participation...

40 CFR 89.203 - General provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... credits to offset the difference between the emission standards and the FEL for such engine families will...) CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES Averaging, Banking, and.... NMHC+NOX. and PM emissions from eligible nonroad engines are described in this subpart. Participation...

40 CFR 89.203 - General provisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... credits to offset the difference between the emission standards and the FEL for such engine families will...) CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES Averaging, Banking, and.... NMHC+NOX. and PM emissions from eligible nonroad engines are described in this subpart. Participation...

40 CFR 1043.41 - EIAPP certification process.

Code of Federal Regulations, 2014 CFR

2014-07-01

... test engine you provide must include appropriate manifolds, aftertreatment devices, electronic control... CONTROLS CONTROL OF NOX, SOX, AND PM EMISSIONS FROM MARINE ENGINES AND VESSELS SUBJECT TO THE MARPOL... application for an EIAPP certificate for each engine family. An EIAPP certificate is valid starting with the...

40 CFR 1043.41 - EIAPP certification process.

Code of Federal Regulations, 2010 CFR

2010-07-01

... test engine you provide must include appropriate manifolds, aftertreatment devices, electronic control... CONTROLS CONTROL OF NOX, SOX, AND PM EMISSIONS FROM MARINE ENGINES AND VESSELS SUBJECT TO THE MARPOL... application for an EIAPP certificate for each engine family. An EIAPP certificate is valid starting with the...

40 CFR 1043.41 - EIAPP certification process.

Code of Federal Regulations, 2012 CFR

2012-07-01

... test engine you provide must include appropriate manifolds, aftertreatment devices, electronic control... CONTROLS CONTROL OF NOX, SOX, AND PM EMISSIONS FROM MARINE ENGINES AND VESSELS SUBJECT TO THE MARPOL... application for an EIAPP certificate for each engine family. An EIAPP certificate is valid starting with the...

40 CFR 1043.41 - EIAPP certification process.

Code of Federal Regulations, 2013 CFR

2013-07-01

... test engine you provide must include appropriate manifolds, aftertreatment devices, electronic control... CONTROLS CONTROL OF NOX, SOX, AND PM EMISSIONS FROM MARINE ENGINES AND VESSELS SUBJECT TO THE MARPOL... application for an EIAPP certificate for each engine family. An EIAPP certificate is valid starting with the...

40 CFR 1043.41 - EIAPP certification process.

Code of Federal Regulations, 2011 CFR

2011-07-01

... test engine you provide must include appropriate manifolds, aftertreatment devices, electronic control... CONTROLS CONTROL OF NOX, SOX, AND PM EMISSIONS FROM MARINE ENGINES AND VESSELS SUBJECT TO THE MARPOL... application for an EIAPP certificate for each engine family. An EIAPP certificate is valid starting with the...

Flexible NO(x) abatement from power plants in the eastern United States.

PubMed

Sun, Lin; Webster, Mort; McGaughey, Gary; McDonald-Buller, Elena C; Thompson, Tammy; Prinn, Ronald; Ellerman, A Denny; Allen, David T

2012-05-15

Emission controls that provide incentives for maximizing reductions in emissions of ozone precursors on days when ozone concentrations are highest have the potential to be cost-effective ozone management strategies. Conventional prescriptive emissions controls or cap-and-trade programs consider all emissions similarly regardless of when they occur, despite the fact that contributions to ozone formation may vary. In contrast, a time-differentiated approach targets emissions reductions on forecasted high ozone days without imposition of additional costs on lower ozone days. This work examines simulations of such dynamic air quality management strategies for NO(x) emissions from electric generating units. Results from a model of day-specific NO(x) pricing applied to the Pennsylvania-New Jersey-Maryland (PJM) portion of the northeastern U.S. electrical grid demonstrate (i) that sufficient flexibility in electricity generation is available to allow power production to be switched from high to low NO(x) emitting facilities, (ii) that the emission price required to induce EGUs to change their strategies for power generation are competitive with other control costs, (iii) that dispatching strategies, which can change the spatial and temporal distribution of emissions, lead to ozone concentration reductions comparable to other control technologies, and (iv) that air quality forecasting is sufficiently accurate to allow EGUs to adapt their power generation strategies.

Emission-factor uncertainties in maritime transport in the Strait of Gibraltar, Spain

NASA Astrophysics Data System (ADS)

Moreno-Gutiérrez, J.; Durán-Grados, V.; Uriondo, Z.; Ángel Llamas, J.

2012-08-01

A reliable and up-to-date maritime emission inventory is essential for atmospheric scientists quantifying the impact of shipping. The objective of this study is to estimate the atmospheric emissions of SO2, NOx, CO2 and PM10 by international merchant shipping in 2007 in the Strait of Gibraltar, Spain, including the Algeciras Bay by two methods. Two methods (both bottom-up) have been used in this study: 1. Establishing engine power-based emission factors (g kWh-1, EPA) or the mass of pollutant per work performed by the engine for each of the relevant components of the exhaust gas from diesel engines and power for each ship. 2. Establishing fuel-based emission factors (kg emitted/t of fuel) or mass of pollutant per mass of combusted fuel for each of the relevant components of the exhaust gas and a fuel-consumption inventory (IMO). In both methods, the means to estimate engine power and fuel-consumption inventories are the same. The exhaust from boilers and incinerators is regarded as a small contributor and excluded. In total, an estimated average of 1 389 111.05 t of CO2, 23 083.09 t of SO2, 32 005.63 t of NOx and 2972 t of PM10 were emitted from January 2007 until December 2007 by international and domestic shipping. The estimated total fuel consumption amounts to 437 405.84 t. The major differences between the estimates generated by the two methods are for NOx (16% in certain cases) and CO (up to 23%). A total difference for all compounds of 3038 t (approximately 2%) has been found between the two methods but it is not areasonable estimate of uncertainty. Therefore, the results for both methods may be considered acceptable because the actual uncontrolled deviations appear in the changes in emission factors that occur for a given engine with age. These deviations are often difficult to quantify and depend on individual shipboard service and maintenance routines. Emission factors for CO and NOx are not constant and depend on engine condition. For example, tests conducted by the authors of this paper demonstrate that when an engine operates under normal in-service conditions, the emissions are within limits. However, with a small fault in injection timing, the NOx emission exceeds the limits (30% higher value in some cases). A fault in the maintenance of the injection nozzles increases the CO emission (15% higher value in some cases).

Impact of biodiesel and renewable diesel on emissions of regulated pollutants and greenhouse gases on a 2000 heavy duty diesel truck

NASA Astrophysics Data System (ADS)

Na, Kwangsam; Biswas, Subhasis; Robertson, William; Sahay, Keshav; Okamoto, Robert; Mitchell, Alexander; Lemieux, Sharon

2015-04-01

As part of a broad evaluation of the environmental impacts of biodiesel and renewable diesel as alternative motor fuels and fuel blends in California, the California Air Resources Board's (CARB) Heavy-duty Diesel Emission Testing Laboratory conducted chassis dynamometer exhaust emission measurements on in-use heavy-heavy-duty diesel trucks (HHDDT). The results presented here detail the impact of biodiesel and renewable diesel fuels and fuel blends as compared to CARB ULSD on particulate matter (PM), regulated gases, and two greenhouse gases emissions from a HHDDT with a 2000 C15 Caterpillar engine with no exhaust after treatment devices. This vehicle was tested over the Urban Dynamometer Driving Schedule (UDDS) and the cruise portion of the California HHDDT driving schedule. Three neat blend stocks (soy-based and animal-based fatty acid methyl ester (FAME) biodiesels, and a renewable diesel) and CARB-certified ultra-low sulfur diesel (CARB ULSD) along with their 20% and 50% blends (blended with CARB ULSD) were tested. The effects of blend level on emission characteristics were discussed on g·km-1 basis. The results showed that PM, total hydrocarbon (THC), and carbon monoxide (CO) emissions were dependent on driving cycles, showing higher emissions for the UDDS cycles with medium load than the highway cruise cycle with high load on per km basis. When comparing CARB ULSD to biodiesels and renewable diesel blends, it was observed that the PM, THC, and CO emissions decreased with increasing blend levels regardless of the driving cycles. Note that biodiesel blends showed higher degree of emission reductions for PM, THC, and CO than renewable diesel blends. Both biodiesels and renewable diesel blends effectively reduced PM emissions, mainly due to reduction in elemental carbon emissions (EC), however no readily apparent reductions in organic carbon (OC) emissions were observed. When compared to CARB ULSD, soy- and animal-based biodiesel blends showed statistically significant increases in nitrogen oxides (NOx) emissions for 50% or higher biodiesel blends. The 20% blends of the biodiesels showed no statistically significant effect on NOx emissions on any cycle. In contrast, renewable diesel slightly decreased NOx emissions and the degree of reduction was statistically significant for 50% or higher blends over the UDDS cycle, but not at the 20% blends. The highway cruise cycles did not show a statistically strong NOx emission trend with increasing blend level of renewable diesel. Biodiesel and renewable fuel impacts on two greenhouse gases, CO2 and N2O emissions were of lower magnitude when compared to other regulated pollutants emissions, showing a change in their emissions within approximately ±3% from the CARB ULSD.

Performance and Emission Investigations of Jatropha and Karanja Biodiesels in a Single-Cylinder Compression-Ignition Engine Using Endoscopic Imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mistri, Gayatri K.; Aggarwal, Suresh K.; Longman, Douglas

Biofuels produced from non-edible sources that are cultivated on marginal lands represent a viable source of renewable and carbon-neutral energy. In this context, biodiesel obtained from Jatropha and Karanja oil seeds have received significant interest, especially in South Asian subcontinent. Both of these fuels are produced from non-edible plant seeds with high oil content, which can be grown on marginal lands. In this research, we have investigated the performance and emission characteristics of Jatropha and Karanja methyl esters (biodiesel) and their blends with diesel. Another objective is to examine the effect of long-term storage on biodiesel’s oxidative stability. The biodieselsmore » were produced at Indian Institute of Technology Kanpur, (IIT Kanpur), India, and the engine experiments were performed in a single cylinder, 4-stroke, compression ignition engine at Argonne National Laboratory (ANL), Chicago. An endoscope was used to visualize in-cylinder combustion events and examine the soot distribution. The effects of fuel and start of injection (SOI) on engine performance and emissions were investigated. Results indicated that ignition delay was shorter with biodiesel. Consequently the cylinder pressure and premixed heat release were higher for diesel compared to biodiesel. Engine performance data for biodiesel (J100, K100) and biodiesel blends (J30, K30) showed an increase in break thermal efficiency (BTE) (10.9%, 7.6% for biodiesel and blend, respectively), BSFC (13.1% and 5.6%), and NOx emission (9.8% and 12.9%), and a reduction in BSHC (8.64% and 12.9%), and BSCO (15.56% and 4.0%). The soot analysis from optical images qualitatively showed that biodiesel and blends produced less soot compared to diesel. The temperature profiles obtained from optical imaging further supported higher NOx in biodiesels and their blends compared to diesel. Additionally, the data indicated that retarding the injection timing leads to higher BSFC, but lower flame temperatures and NOx levels along with higher soot formation for all test fuels. The physicochemical properties such as fatty acid profile, cetane number, and oxygen content in biodiesels support the observed combustion and emission characteristics of the fuels tested in this study. Finally, the effect of long-term storage is found to increase the glycerol content, acid value and cetane number of the two biodiesels, indicating some oxidation of unsaturated fatty acids in the fuels.« less

Production of Nitrogen Oxides by Laboratory Simulated Transient Luminous Events

NASA Astrophysics Data System (ADS)

Peterson, H.; Bailey, M.; Hallett, J.; Beasley, W.

2007-12-01

Restoration of the polar stratospheric ozone layer has occurred at rates below those originally expected following reductions in chlorofluorocarbon (CFC) usage. Additional reactions affecting ozone depletion now must also be considered. This research examines nitrogen oxides (NOx) produced in the middle atmosphere by transient luminous events (TLEs), with NOx production in this layer contributing to the loss of stratospheric ozone. In particular, NOx produced by sprites in the mesosphere would be transported to the polar stratosphere via the global meridional circulation and downward diffusion. A pressure-controlled vacuum chamber was used to simulate middle atmosphere pressures, while a power supply and in-chamber electrodes were used to simulate TLEs in the pressure controlled environment. Chemiluminescence NOx analyzers were used to sample NOx produced by the chamber discharges- originally a Monitor Labs Model 8440E, later a Thermo Environment Model 42. Total NOx production for each discharge as well as NOx per ampere of current and NOx per Joule of discharge energy were plotted. Absolute NOx production was greatest for discharge environments with upper tropospheric pressures (100-380 torr), while NOx/J was greatest for discharge environments with stratospheric pressures (around 10 torr). The different production efficiencies in NOx/J as a function of pressure pointed to three different production regimes, each with its own reaction mechanisms: one for tropospheric pressures, one for stratospheric pressures, and one for upper stratospheric to mesospheric pressures (no greater than 1 torr).

75 FR 22895 - Control of Emissions From New Marine Compression-Ignition Engines at or Above 30 Liters per Cylinder

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-30

...EPA is finalizing emission standards for new marine diesel engines with per-cylinder displacement at or above 30 liters (called Category 3 marine diesel engines) installed on U.S. vessels. These emission standards are equivalent to those adopted in the amendments to Annex VI to the International Convention for the Prevention of Pollution from Ships (MARPOL Annex VI). The emission standards apply in two stages--near-term standards for newly built engines will apply beginning in 2011; long-term standards requiring an 80 percent reduction in NOX emissions will begin in 2016. We are also finalizing a change to our diesel fuel program that will allow for the production and sale of 1,000 ppm sulfur fuel for use in Category 3 marine vessels. In addition, the new fuel requirements will generally forbid the production and sale of other fuels above 1,000 ppm sulfur for use in most U.S. waters, unless alternative devices, procedures, or compliance methods are used to achieve equivalent emissions reductions. We are adopting further provisions under the Act to Prevent Pollution from Ships, especially to apply the emission standards to engines covered by MARPOL Annex VI that are not covered by the Clean Air Act, and to require that these additional engines use the specified fuels (or equivalents). The final regulations also include technical amendments to our motor vehicle and nonroad engine regulations; many of these changes involve minor adjustments or corrections to our recently finalized rule for new nonroad spark-ignition engines, or adjustment to other regulatory provisions to align with this recent final rule.

40 CFR 1068.101 - What general actions does this regulation prohibit?

Code of Federal Regulations, 2014 CFR

2014-07-01

..., operating an engine without a supply of appropriate quality urea if the emissions control system relies on urea to reduce NOx emissions or the use of incorrect fuel or engine oil that renders the emissions... manufacturers of new engines, manufacturers of equipment containing these engines, and manufacturers of new...

40 CFR 1068.101 - What general actions does this regulation prohibit?

Code of Federal Regulations, 2012 CFR

2012-07-01

..., operating an engine without a supply of appropriate quality urea if the emissions control system relies on urea to reduce NOx emissions or the use of incorrect fuel or engine oil that renders the emissions... manufacturers of new engines, manufacturers of equipment containing these engines, and manufacturers of new...

40 CFR 1068.101 - What general actions does this regulation prohibit?

Code of Federal Regulations, 2013 CFR

2013-07-01

..., operating an engine without a supply of appropriate quality urea if the emissions control system relies on urea to reduce NOx emissions or the use of incorrect fuel or engine oil that renders the emissions... manufacturers of new engines, manufacturers of equipment containing these engines, and manufacturers of new...

Reduction of Fuel Consumption and Exhaust Pollutant Using Intelligent Transport Systems

PubMed Central

Nasir, Mostofa Kamal; Md Noor, Rafidah; Kalam, M. A.; Masum, B. M.

2014-01-01

Greenhouse gas emitted by the transport sector around the world is a serious issue of concern. To minimize such emission the automobile engineers have been working relentlessly. Researchers have been trying hard to switch fossil fuel to alternative fuels and attempting to various driving strategies to make traffic flow smooth and to reduce traffic congestion and emission of greenhouse gas. Automobile emits a massive amount of pollutants such as Carbon Monoxide (CO), hydrocarbons (HC), carbon dioxide (CO2), particulate matter (PM), and oxides of nitrogen (NOx). Intelligent transport system (ITS) technologies can be implemented to lower pollutant emissions and reduction of fuel consumption. This paper investigates the ITS techniques and technologies for the reduction of fuel consumption and minimization of the exhaust pollutant. It highlights the environmental impact of the ITS application to provide the state-of-art green solution. A case study also advocates that ITS technology reduces fuel consumption and exhaust pollutant in the urban environment. PMID:25032239

Gas- and particle-phase primary emissions from in-use, on-road gasoline and diesel vehicles

NASA Astrophysics Data System (ADS)

May, Andrew A.; Nguyen, Ngoc T.; Presto, Albert A.; Gordon, Timothy D.; Lipsky, Eric M.; Karve, Mrunmayi; Gutierrez, Alváro; Robertson, William H.; Zhang, Mang; Brandow, Christopher; Chang, Oliver; Chen, Shiyan; Cicero-Fernandez, Pablo; Dinkins, Lyman; Fuentes, Mark; Huang, Shiou-Mei; Ling, Richard; Long, Jeff; Maddox, Christine; Massetti, John; McCauley, Eileen; Miguel, Antonio; Na, Kwangsam; Ong, Richard; Pang, Yanbo; Rieger, Paul; Sax, Todd; Truong, Tin; Vo, Thu; Chattopadhyay, Sulekha; Maldonado, Hector; Maricq, M. Matti; Robinson, Allen L.

2014-05-01

Tailpipe emissions from sixty-four unique light-duty gasoline vehicles (LDGVs) spanning model years 1987-2012, two medium-duty diesel vehicles and three heavy-duty diesel vehicles with varying levels of aftertreatment were characterized at the California Air Resources Board Haagen-Smit and Heavy-Duty Engine Testing Laboratories. Each vehicle was tested on a chassis dynamometer using a constant volume sampler, commercial fuels and standard duty cycles. Measurements included regulated pollutants such as carbon monoxide (CO), total hydrocarbons (THC), nitrogen oxides (NOx), and particulate matter (PM). Off-line analyses were performed to speciate gas- and particle-phase emissions. The data were used to investigate trends in emissions with vehicle age and to quantify the effects of different aftertreatment technologies on diesel vehicle emissions (e.g., with and without a diesel particulate filter). On average, newer LDGVs that met the most recent emissions standards had substantially lower emissions of regulated gaseous pollutants (CO, THC and NOx) than older vehicles. For example, THC emissions from the median LDGV that met the LEV2 standard was roughly a factor of 10 lower than the median pre-LEV vehicle; there were also substantial reductions in NOx (factor of ∼100) and CO (factor of ∼10) emissions from pre-LEV to LEV2 vehicles. However, reductions in LDGV PM mass emissions were much more modest. For example, PM emission from the median LEV2 vehicle was only a factor of three lower than the median pre-LEV vehicle, mainly due to the reductions in organic carbon emissions. In addition, LEV1 and LEV2 LDGVs had similar PM emissions. Catalyzed diesel particulate filters reduced CO, THC and PM emissions from HDDVs by one to two orders of magnitude. Comprehensive organic speciation was performed to quantify priority air toxic emissions and to estimate the secondary organic aerosol (SOA) formation potential. The data suggest that the SOA production from cold-start LDGVs exhaust will likely exceed primary PM emissions from LDGVs and could potentially exceed SOA formation from on-road diesel vehicles.

Final Rule for Emission Standards for Locomotives and Locomotive Engines

EPA Pesticide Factsheets

In 1998, EPA promulgated final exhaust emission standards for oxides of nitrogen (NOx), hydrocarbons (HC), carbon monoxide (CO), particulate matter (PM) and smoke for newly manufactured and remanufactured locomotives and locomotive engines.

Effect of CO, NOx and SO2 on ROS production, photosynthesis and ascorbate–glutathione pathway to induce Fragaria×annasa as a hyperaccumulator☆

PubMed Central

Muneer, Sowbiya; Kim, Tae Hwan; Choi, Byung Chul; Lee, Beom Seon; Lee, Jeong Hyun

2013-01-01

A study was conducted to determine the effect of carbon monoxide (CO), nitroxide (NOx) and sulfur dioxide (SO2) on ROS production, photosynthesis and ascorbate–glutathione pathway in strawberry plants. The results showed that both singlet oxygen (O2−1) and hydrogen peroxide (H2O2) content increased in CO, NOx and SO2 treated strawberry leaves. A drastic reduction of primary metabolism of plants (photosynthesis), with the closure of stomata, resulted in a reduction of protein, carbohydrate and sucrose content due to production of reactive oxygen species (ROS) under prolonged exposure of gas stress. The resulting antioxidant enzymes were increased under a low dose of gas stress, whereas they were decreased due to a high dose of gas stress. Our results indicate that increased ROS may act as a signal to induce defense responses to CO, NOx and SO2 gas stress. The increased level of antioxidant enzymes plays a significant role in plant protection due to which strawberry plants can be used as a hyperaccumulator to maintain environmental pollution, however, the defense capacity cannot sufficiently alleviate oxidative damage under prolonged exposure of CO, NOx and SO2 stress. PMID:25460723

Rational design of template-free MnOx-CeO2 hollow nanotube as de-NOx catalyst at low temperature

NASA Astrophysics Data System (ADS)

Li, Chenlu; Tang, Xiaolong; Yi, Honghong; Wang, Lifeng; Cui, Xiaoxu; Chu, Chao; Li, Jingying; Zhang, Runcao; Yu, Qingjun

2018-01-01

MnOx-CeO2 hollow nanotube was synthesized for the low temperature selective catalytic reduction (SCR) of NOx with NH3. The nanotube was fabricated firstly through the interfacial oxidation-reduction reaction by dealing the Ce(OH)CO3 intermediate with KMnO4 aqueous solution, then followed by selective wash with HNO3. The catalysts were systematically examined by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, elemental mapping, X-ray photoelectron spectroscopy, NH3 temperature-programmed desorption measurements and catalytic activity test. It was found that the as-prepared MnOx-CeO2-B nanotube exhibited best NOx removal efficiency among the catalysts investigated, where 96% NOx conversion at 100 °C at a space velocity of 30000 h-1 was obtained. Meanwhile, superior resistance to H2O and SO2 was achieved as well as high thermal stability. On the basis of various analysis results, the remarkable de-NOx performance of the MnOx-CeO2-B nanobube could be attributed to the uniform distribution of active species, abundant content of Mn4+ and Oα species, and especially the hollow porous architectures provided huge specific surface area and sufficient acidic sites.

Experimental investigations of the hydrogen addition effects on diesel engine performance

NASA Astrophysics Data System (ADS)

Mirica, I.; Pana, C.; Negurescu, N.; Cernat, A.; Nutu, C.

2016-08-01

In the global content regarding the impact on the environmental of the gases emissions resulted from the fossil fuels combustion, an interest aspect discussed on the 21st Session of the Conference of the Parties from the 2015 Paris Climate Conference and the gradual diminution of the worldwide oil reserves contribute to the necessity of searching of alternative energy from durable and renewable resources. At the use of hydrogen as addition in air to diesel engine, the level of CO, HC and smoke from the exhaust gases will decrease due to the improvement of the combustion process. At low and medium partial loads and low hydrogen energetic ratios used the NOX emission level can decrease comparative to classic diesel engine. The hydrogen use as fuel for diesel engine leads to the improving of the energetic and emissions performance of the engine due to combustion improvement and reduction of carbon content. The paper presents, in a comparative way, results of the experimental researches carried on a truck compression ignition engine fuelled with diesel fuel and with hydrogen diesel fuel and hydrogen as addition in air at different engine operation regimes. The results obtained during experimental investigations show better energetic and pollution performance of the engine fuelled with hydrogen as addition in air comparative to classic engine. The influences of hydrogen addition on engine operation are shown.

Reconciling NOx emissions reductions and ozone trends in ...

EPA Pesticide Factsheets

Dynamic evaluation seeks to assess the ability of photochemical models to replicate changes in air quality as emissions and other conditions change. When a model fails to replicate an observed change, a key challenge is to discern whether the discrepancy is caused by errors in meteorological simulations, errors in emission magnitudes and changes, or inaccurate responses of simulated pollutant concentrations to emission changes. In this study, the Community Multiscale Air Quality (CMAQ) model is applied to simulate the ozone (O3) change after the NOx SIP Call and mobile emission controls substantially reduced nitrogen oxides (NOx) emissions in the eastern U.S. from 2002 to 2006. For both modeled and observed O3, changes in episode average daily maximal 8-h O3 were highly correlated (R2 = 0.89) with changes in the 95th percentile, although the magnitudes of reductions increased nonlinearly at high percentile O3 concentrations. Observed downward changes in mean NOx (−11.6 to −2.5 ppb) and 8-h O3 (−10.4 to −4.7 ppb) concentrations in metropolitan areas in the NOx SIP Call region were under-predicted by 31%–64% and 26%–66%, respectively. The under-predicted O3 improvements in the NOx SIP Call region could not be explained by adjusting for temperature biases in the meteorological input, or by considering uncertainties in the chemical reaction rate constants. However, the under-prediction in O3 improvements could be alleviated by 5%–31% by constraining NO

Ethanol and air quality: influence of fuel ethanol content on emissions and fuel economy of flexible fuel vehicles.

PubMed

Hubbard, Carolyn P; Anderson, James E; Wallington, Timothy J

2014-01-01

Engine-out and tailpipe emissions of NOx, CO, nonmethane hydrocarbons (NMHC), nonmethane organic gases (NMOG), total hydrocarbons (THC), methane, ethene, acetaldehyde, formaldehyde, ethanol, N2O, and NH3 from a 2006 model year Mercury Grand Marquis flexible fuel vehicle (FFV) operating on E0, E10, E20, E30, E40, E55, and E80 on a chassis dynamometer are reported. With increasing ethanol content in the fuel, the tailpipe emissions of ethanol, acetaldehyde, formaldehyde, methane, and ammonia increased; NOx and NMHC decreased; while CO, ethene, and N2O emissions were not discernibly affected. NMOG and THC emissions displayed a pronounced minimum with midlevel (E20-E40) ethanol blends; 25-35% lower than for E0 or E80. Emissions of NOx decreased by approximately 50% as the ethanol content increased from E0 to E30-E40, with no further decrease seen with E55 or E80. We demonstrate that emission trends from FFVs are explained by fuel chemistry and engine calibration effects. Fuel chemistry effects are fundamental in nature; the same trend of increased ethanol, acetaldehyde, formaldehyde, and CH4 emissions and decreased NMHC and benzene emissions are expected for all FFVs. Engine calibration effects are manufacturer and model specific; emission trends for NOx, THC, and NMOG will not be the same for all FFVs. Implications for air quality are discussed.

Development of reduction scenarios for criteria air pollutants emission in Tehran Traffic Sector, Iran.

PubMed

Mohammadiha, Amir; Malakooti, Hossein; Esfahanian, Vahid

2018-05-01

Transport-related pollution as the main source of air pollution must be reduced in Tehran mega-city. The performance of various developed scenarios including BAU (Business As Usual) as baseline scenario, ECV (Elimination of carburetor equipped Vehicle), NEM (New Energy Motorcycles), HES (Higher Emission Standard), VCR (Vehicle Catalyst Replacement), FQE (Fuel Quality Enhancement), DPF (Diesel Particulate Filter) and TSA (Total Scenarios Aggregation) are evaluated by International Vehicle Model up to 2028. In the short term, the ECV, VCR, and FQE scenarios provided high performance in CO, VOCs and NOx emissions control. Also FQE has an excellent effect on SOx emission reduction (86%) and DPF on PM emissions (20%). In the mid-term, the VCR, ECV, and FQE scenarios were presented desirable mean emission reduction on CO, VOCs, and NOx. Moreover, NOx emission reduction of DPF scenario is the most common (14%). Again FQE scenario proves to have great effect on SOx emission reduction in mid-term (86%), DPF and HES scenarios on PM (DPF: 49% and HES: 17%). Finally for the long term, VCR, ECV, FQE, and NEM scenarios were shown good performance in emission control on CO, VOCs and NOx. For SOx only FQE has a good effect in all time periods (FQE: 86%) and DPF and HES scenarios have the best effect on PM emission reduction respectively (DPF: 51% and HES: 27%) compared with BAU scenario. However, DPF scenario increases 12% SOx emission in long-term (2028). It can be generally concluded that VCR and ECV scenarios would achieve a significant reduction on gaseous pollutants emission except for SOx in general and FQE scenarios have desirable performance for all gaseous pollutants in the short term and also for SOx and VOCs in long term. In addition, the DPF and HES would be desirable scenario for emission control on PM in Tehran Traffic Sector. Copyright © 2017 Elsevier B.V. All rights reserved.