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Second Generation Advanced Reburning for High Efficiency NOx Control

Description: This project is designed to develop a family of novel NO{sub x} control technologies, called Second Generation Advanced Reburning (SGAR) which has the potential to achieve 90+ NO{sub x} control in coal fired boilers at a significantly lower cost than Selective Catalytic Reduction. The ninth reporting period in Phase II (October 1-December 31, 1999) included preparation of the 10 x 10{sup 6} Btu/hr Tower Furnace for tests and setting the SGAR model to predict process performance under Tower Furnace conditions. Based on results of previous work, a paper has been prepared and submitted for the presentation at the 28 Symposium (International) on Combustion to be held at the University of Edinburgh, Scotland.
Date: December 31, 1999
Creator: Zamansky, Vladimir M. & Lissianski, Vitali V.
Partner: UNT Libraries Government Documents Department

Second Generation Advanced Reburning for High Efficiency NOx Control

Description: This project is designed to develop a family of novel NO{sub x} control technologies, called Second Generation Advanced Reburning which has the potential to achieve 90+ NO{sub x} control in coal fired boilers at a significantly lower cost than Selective Catalytic Reduction. The seventh reporting period in Phase II (April 1-June 30, 1999) included experimental activities and combined chemistry-mixing modeling on advanced gas reburning. The goal of combustion tests was to determine the efficiency of advanced reburning using coal as the reburning fuel. Tests were conducted in Boiler Simulator Facility (BSF). Several coals were tested. The modeling effort was focused on the description of N-agent injection along with overfire air. Modeling identified process parameters that can be used to optimize the AR-Lean process.
Date: June 30, 1999
Creator: Zamansky, Vladimir M.; Maly, Peter M. & Lissianski, Vitali V.
Partner: UNT Libraries Government Documents Department

Second Generation Advanced Reburning for High Efficiency NOx Control

Description: This project is designed to develop a family of novel NO{sub x} control technologies, called Second Generation Advanced Reburning (SGAR) which has the potential to achieve 90+ NO{sub x} control in coal fired boilers at a significantly lower cost than Selective Catalytic Reduction. The tenth reporting period in Phase II (January 1-March 31, 2000) included proof-of concept tests in the 10 x 10{sup 6} Btu/hr Tower Furnace. Several variants of Second Generation Advanced Reburning (SGAR) were studied, including AR-Lean, AR-Rich, reburning + SNCR, and Multiple Injection Advanced Reburning (MIAR). Tests demonstrated that the SGAR performance was the most effective under MIAR conditions achieving maximum overall NO{sub x} reduction of 96%.
Date: March 31, 2000
Creator: Zamansky, Vladimir M. & Maly, Pete M.
Partner: UNT Libraries Government Documents Department

Supported Molten Metal Catalysis. A New Class of Catalysts

Description: We describe a new class of heterogeneous catalysts called supported molten metal catalysis (SMMC), in which molten metal catalysts are dispersed as nanodroplets on the surface of porous supports, allowing much larger active surface area than is possible in conventional contacting techniques for catalytic metals that are molten under reaction conditions, thus greatly enhancing their activity and potential utility. Specific examples of different types of reactions are provided to demonstrate the broad applicability of the technique in designing active, selective, and stable new catalysts. It is shown that dispersing the molten metal on a support in the suggested manner can enhance the rate of a reaction by three to four orders of magnitude as a result of the concomitant increase in the active surface area. New reaction examples include {gamma}-Al{sub 2}O{sub 3} supported molten Te (melting point 450 C) and Ga (MP 30 C) catalysts for bifunctional methylcyclohexane dehydrogenation. These catalysts provide activity similar to conventional Pt-based catalysts for this with better resistance to coking. In addition, results are described for a controlled pore glass supported molten In (MP 157 C) catalyst for the selective catalytic reduction of NO with ethanol in the presence of water, demonstrating activities superior to conventional catalysts for this reaction. A discussion is also provided on the characterization of the active surface area and dispersion of these novel supported catalysts. It is clear based on the results described that the development of new active and selective supported molten metal catalysts for practical applications is entirely plausible.
Date: June 2, 2006
Creator: Datta, Ravindra; Singh, Ajeet; Serban, Manuela & Halasz, Istvan
Partner: UNT Libraries Government Documents Department

SECOND GENERATION ADVANCED REBURNING FOR HIGH EFFICIENCY NOx CONTROL

Description: This project is designed to develop a family of novel NO{sub x} control technologies, called Second Generation Advanced Reburning which has the potential to achieve 90+ NO{sub x} control in coal fired boilers at a significantly lower cost than Selective Catalytic Reduction. The eighth reporting period in Phase II (July 1--September 26, 1999) included combined chemistry-mixing modeling on advanced gas reburning and experimental activities in support of modeling. Modeling efforts focused on description of AR-Lean--combination of basic reburning and co-injection of N-agent with overfire air. Modeling suggests that efficiency of AR-Lean strongly depends on the amount of the reburning fuel, temperature of flue gas at the point of OFA/N-agent injection, and evaporation time of N-agent. The model describes the most important features of AR-Lean and can be used for AR-Lean optimization.
Date: October 29, 1999
Creator: Zamansky, Vladimir M.; Maly, Peter M. & Lissianski, Vitali V.
Partner: UNT Libraries Government Documents Department

MECHANISTIC STUDIES AND DESIGN OF HIGHLY ACTIVE CUPRATE CATALYSTS FOR THE DIRECT DECOMPOSITION AND SELECTIVE REDUCTION OF NITRIC OXIDE AND HYDROCARBONS TO NITROGEN FOR ABATEMENT OF STACK EMISSIONS

Description: A flow trough type catalytic reactor system was adequately modified for NO related catalytic and adsorption measurements, including the on-line connection of a digital chemiluminescent NO-NO{sub x} analyzer to the reactor outlet system. Moreover, we have largely completed the installation of an FTIR coupled catalytic system containing a HTEC cell for high temperature DRIFT studies. Three different barium cuprate samples, Ba{sub 2}CuO{sub 3}, BaCuO{sub 2}, and Ba{sub 2}Cu{sub 3}O{sub 5} were synthesized and characterized by powder XRD for catalytic tests. Prior to catalytic studies over these cuprates, a new, liquid indium based supported molten metal catalyst (In-SMMC) was tested in the reduction of NO by various reductants. In the presence of excess O{sub 2} and H{sub 2}O, the In-SMMC proved to be more active for the selective catalytic reduction (SCR) of NO to N{sub 2} by ethanol than most other catalysts. Using C{sub 1}-C{sub 3} alcohols as reductants, self sustained periodic oscillations observed in the NO{sub x} concentrations of reactor effluents indicated the first time that radical intermediates can be involved in the SCR of NO by alcohols. Further, In-SMMC is the only effective and water tolerant SCR catalyst reported thus far which contains SiO{sub 2} support. Thus, this novel catalyst opens up a promising new alternative for developing an effective and durable catalyst for NO{sub x} abatement in stack emission.
Date: April 30, 1998
Partner: UNT Libraries Government Documents Department

PILLARED CLAYS AS SUPERIOR CATALYSTS FOR SELECTIVE CATALYTIC REDUCTION OF NITRIC OXIDE

Description: In the last annual reports, we reported Cu-exchanged pillared clays as superior selective catalytic reduction (SCR) catalysts. During the past year we explored the possibilities with MCM-41, a new class of molecular sieve. In this report, Rh exchanged Al-MCM-41 is studied for the SCR of NO by C{sub 3}H{sub 6} in the presence of excess oxygen. It shows a high activity in converting NO to N{sub 2} and N{sub 2}O at low temperatures. In situ FT-IR studies indicate that Rh-NO{sup +} species (1910-1898 cm{sup {minus}1}) is formed on the Rh-Al-MCM-41 catalyst in flowing NO/He, NO+O{sub 2}/He and NO+C{sub 3}H{sub 6}+O{sub 2}/He at 100-350 C. This species is quite active in reacting with propylene and/or propylene adspecies (e.g., {pi}-C{sub 3}H{sub 5}, polyene, etc.) at 250 C in the presence/absence of oxygen, leading to the formation of the isocyanate species (Rh-NCO, at 2174 cm{sup {minus}1}), CO and CO{sub 2}. Rh-NCO is also detected under reaction conditions. A possible reaction pathway for reduction of NO by C{sub 3}H{sub 6} is proposed. In the SCR reaction, Rh-NO{sup +} and propylene adspecies react to generate the Rh-NCO species, then Rh-NCO reacts with O{sub 2}, NO and NO{sub 2} to produce N{sub 2}, N{sub 2}O and CO{sub 2}. Rh-NO{sup +} and Rh-NCO species are two main intermediates for the SCR reaction on Rh-Al-MCM-41 catalyst.
Date: March 31, 1999
Creator: Yang, R. T. & Long, R.Q.
Partner: UNT Libraries Government Documents Department

SECOND GENERATION ADVANCED REBURNING FOR HIGH EFFICIENCY NOx CONTROL

Description: This project is designed to develop a family of novel NO{sub x} control technologies, called Second Generation Advanced Reburning which has the potential to achieve 90+ NO{sub x} control in coal fired boilers at a significantly lower cost than Selective Catalytic Reduction. The sixth reporting period in Phase II (January 1-March 31, 1999) included experimental activities and combined chemistry-mixing modeling on advanced gas reburning. The goal of combustion tests was to continue the work on identifying prospective promoters for the advanced reburning process. Tests were conducted in Controlled Temperature Tower (CTT) and Boiler Simulator Facility (BSF). Tests showed that some promoters significantly affect the reburning process when co-injected with NH{sub 3} . The promoters injected into reburning zone without NH{sub 3} in the amount 30 ppm do not significantly affect the reburning process. The modeling effort was focused on the description of Na effect on CO emissions in advanced reburning. Increase in CO concentration in flue gas upon Na injection results from inhibition of CO oxidation by Na species in the burnout zone.
Date: April 29, 1999
Creator: Maly, Peter M.; Lissianski, Vitali V. & Zamansky, Vladimir M.
Partner: UNT Libraries Government Documents Department

Selective Catalytic Reduction of Diesel Engine Nox Emissions Using Ethanol as a Reductant

Description: NOx emissions from a heavy-duty diesel engine were reduced by more than 90% and 80% utilizing a full-scale ethanol-SCR system for space velocities of 21000/h and 57000/h respectively. These results were achieved for catalyst temperatures between 360 and 400 C and for C1:NOx ratios of 4-6. The SCR process appears to rapidly convert ethanol to acetaldehyde, which subsequently slipped past the catalyst at appreciable levels at a space velocity of 57000/h. Ammonia and N2O were produced during conversion; the concentrations of each were higher for the low space velocity condition. However, the concentration of N2O did not exceed 10 ppm. In contrast to other catalyst technologies, NOx reduction appeared to be enhanced by initial catalyst aging, with the presumed mechanism being sulfate accumulation within the catalyst. A concept for utilizing ethanol (distilled from an E-diesel fuel) as the SCR reductant was demonstrated.
Date: August 24, 2003
Creator: Kass, M. D.; Thomas, J. F.; Lewis, S. A., Sr.; Storey, J. M.; Domingo, N. & Graves, R. L.
Partner: UNT Libraries Government Documents Department

Educating Consumers: New Content on Diesel Vehicles, Diesel Exhaust Fluid, and Selective Catalytic Reduction Technologies on the AFDC (Presentation)

Description: Presentation covers new content available on the Alternative Fuels and Advanced Vehicle Data Center regarding diesel vehicles, diesel exhaust fluid, and selective catalytic reduction technologies.
Date: August 5, 2008
Creator: Brodt-Giles, D.
Partner: UNT Libraries Government Documents Department

JV 58-Effects of Biomass Combustion on SCR Catalyst

Description: A portable slipstream selective catalytic reduction (SCR) reactor was installed at a biomass cofired utility boiler to examine the rates and mechanisms of catalyst deactivation when exposed to biomass combustion products. The catalyst was found to deactivate at a much faster rate than typically found in a coal-fired boiler, although this may have been the result of high ash loading rather than a general property of biomass combustion. Deactivation was mainly the result of alkali and alkaline-earth sulfate formation and growth in catalyst pores, apparently caused by alkaline-earth ash deposition on or near the pore sites. The high proportion of biomass in the fuel contributed to elevated levels of alkali and alkaline-earth material in the ash when compared to coal ash, and these higher levels provided more opportunity for sulfate formation. Based on laboratory tests, neither catalyst material nor ammonia contributed measurably to ash mass gains via sulfation. A model constructed using both field and laboratory data was able to predict catalyst deactivation of catalysts under subbituminous coal firing but performed poorly at predicting catalyst deactivation under cofiring conditions. Because of the typically higher-than coal levels of alkali and alkaline-earth elements present in biomass fuels that are available for sulfation at typical SCR temperatures, the use of SCR technology and biomass cofiring needs to be carefully evaluated prior to implementation.
Date: August 31, 2006
Creator: Folkedahl, Bruce C.; Zygarlicke, Christopher J.; Strege, Joshua R.; McCollor, Donald P.; Laumb, Jason D. & Kong, Lingbu
Partner: UNT Libraries Government Documents Department

Catalyst Additives to Enhance Mercury Oxidation and Capture

Description: Preliminary research has shown that SCR catalysts employed for nitrogen-oxide reduction can effectively oxidize mercury. This report discusses initial results from fundamental investigations into the behavior of mercury species in the presence of SCR catalysts at Southern Research Institute. Three different SCR catalysts are being studied. These are honeycomb-type, plate-type, and a hybrid-type catalyst. The catalysts are manufactured and supplied by Cormetech Inc., Hitachi America Ltd., and Haldor-Topsoe Inc., respectively. Test methods and experimental procedures were developed for current and future testing. The methods and procedures equalize factors influencing mercury adsorption and oxidation (surface area, catalyst activity, and pore structure) that normally differ for each catalyst type. Initial testing was performed to determine the time necessary for each catalyst to reach surface-adsorption equilibrium. In addition, the fraction of Hg oxidized by each of the SCR catalyst types is being investigated, for a given amount of catalyst and flow rate of mercury and flue gas. The next major effort will be to examine the kinetics of mercury oxidation across the SCR catalysts with respect to changes in mercury concentration and with respect to HCl concentration. Hg-sorption equilibrium times will also be investigated with respect to ammonia concentration in the simulated flue gas.
Date: December 31, 2004
Creator: Cannon, Jared W. & Gale, Thomas K.
Partner: UNT Libraries Government Documents Department

Discovery of New NOx Reduction Catalysts for CIDI Engines Using Combinatorial Techniques

Description: This project for the discovery of new lean reduction NOx catalysts was initiated on August 16th, 2002 and is now into its fourth year. Several materials have already been identified as NOx reduction catalysts for possible future application. NOx reduction catalysts are a critical need in the North American vehicle market since these catalysts are needed to enable both diesels and lean gasoline engines to meet the 2007-2010 emission standards. Hydrocarbon selective catalytic reduction (SCR) is a preferred technology since it requires no infrastructure changes (as may be expected for urea SCR) and most likely has the simplest engine control strategy of the three proposed NOx reduction approaches. The use of fast throughput techniques and informatics greatly enhances the possibility of discovering new NOx reduction catalysts. Using fast throughput techniques this project has already screened over 3000 new materials and evaluates hundreds of new materials a month. Evaluating such a high number of new materials puts this approach into a very different paradigm than previous discovery approaches for new NOx reduction catalysts. With so much data on materials it is necessary to use statistical techniques to identify the potential catalysts and these statistical techniques are needed to optimize compositions of the multi-component materials that are identified under the program as possible new lean NOx catalysts. Several new materials have conversions in excess of 80% at temperatures above 300 C. That is more than twice the activity of previous HC SCR materials. These materials are candidates for emission control on heavy-duty systems (i.e.; over 8500 pounds gross weight). Tests of one of the downselected materials on an engine dynamometer show NOx reductions greater than 80% under some conditions even though the net NOx reductions on the HWFET and the US06 cycles were relatively low. The program is scheduled to continue until ...
Date: August 15, 2005
Creator: Blint, Richard J
Partner: UNT Libraries Government Documents Department

Simultaneous SO{sub 2}/NO{sub x} abatement using zeolite-supported copper. Progress report, January 1--March 31, 1996

Description: The authors have begun the investigation of the adsorption of NO on the Cu/{gamma}-alumina samples. The object of this aspect of the project is to investigate the modes of adsorption of NO on the Cu/{gamma}-alumina sorbents, to investigate the potential activity of these materials for the catalysis of the reduction of NO. Additionally, when subsequent measurements of NO interacting with a sulfated sorbent are investigated, a baseline of data will have been obtained which can be used to evaluate the effects of surface sulfation on the adsorption process in the absence of other competing effects. Based on the current results and by comparing results with those found by others, the authors have determined that the copper species exist predominantly as isolated copper atoms on the aluminum oxide surface, which behave chemically as copper aluminate. The copper species is responsible for the formation of an NO/Cu{sup 2+} complex which gives rise to an infrared absorption at 1,863 cm{sup {minus}1}. There do exist some Cu{sup +} species on the surface, which are formed only after some time by an interaction with NO, which give rise to an NO{sup {minus}}/Cu{sup +} complex with an infrared absorption at approximately 1,700 cm{sup {minus}1}. Additionally, an intense feature at 1,640 cm{sup {minus}1} is observed which may be due to NO{sub 2} on the surface, which is the expected oxidation product if NO reduces Cu from Cu{sup 2+} to Cu{sup +}.
Date: December 31, 1996
Creator: Mitchell, M.B. & White, M.G.
Partner: UNT Libraries Government Documents Department

Cost analysis of NOx control alternatives for stationary gas turbines

Description: The use of stationary gas turbines for power generation has been growing rapidly with continuing trends predicted well into the future. Factors that are contributing to this growth include advances in turbine technology, operating and siting flexibility and low capital cost. Restructuring of the electric utility industry will provide new opportunities for on-site generation. In a competitive market, it maybe more cost effective to install small distributed generation units (like gas turbines) within the grid rather than constructing large power plants in remote locations with extensive transmission and distribution systems. For the customer, on-site generation will provide added reliability and leverage over the cost of purchased power One of the key issues that is addressed in virtually every gas turbine application is emissions, particularly NO{sub x} emissions. Decades of research and development have significantly reduced the NO{sub x} levels emitted from gas turbines from uncontrolled levels. Emission control technologies are continuing to evolve with older technologies being gradually phased-out while new technologies are being developed and commercialized. The objective of this study is to determine and compare the cost of NO{sub x} control technologies for three size ranges of stationary gas turbines: 5 MW, 25 MW and 150 MW. The purpose of the comparison is to evaluate the cost effectiveness and impact of each control technology as a function of turbine size. The NO{sub x} control technologies evaluated in this study include: Lean premix combustion, also known as dry low NO{sub x} (DLN) combustion; Catalytic combustion; Water/steam injection; Selective catalytic reduction (SCR)--low temperature, conventional, high temperature; and SCONO{sub x}{trademark}.
Date: November 5, 1999
Creator: Major, Bill
Partner: UNT Libraries Government Documents Department

Investigation of Mixed Metal Sorbent/Catalysts for the Simultaneous Removal of Sulfur and Nitrogen Oxides

Description: Simultaneous removal of SO{sub 2} and NO{sub x} using a regenerable solid sorbent will constitute an important improvement over the use of separate processes for the removal of these two pollutants from stack gases and possibly eliminate several shortcomings of the individual SO{sub 2} and NO{sub x} removal operations. The work done at PETC and the DOE-funded investigation of the investigators on the sulfation and regeneration of alumina-supported cerium oxide sorbents have shown that they can perform well at relatively high temperatures (823-900 K) as regenerable desulfurization sorbents. Survey of the recent literature shows that addition of copper oxide to ceria lowers the sulfation temperature of ceria down to 773 K, sulfated ceria-based sorbents can function as selective SCR catalysts even at elevated temperatures, SO{sub 2} can be directly reduced to sulfur by CO on CuO-ceria catalysts, and ceria-based catalysts may have a potential for selective catalytic reduction of NO{sub x} by methane. These observations indicate a possibility of developing a ceria-based sorbent/catalyst which can remove both SO{sub 2} and NO{sub x} from flue gases within a relatively wide temperature window, produce significant amounts of elemental sulfur during regeneration, and use methane for the selective catalytic reduction of NO{sub x}.
Date: August 1, 2001
Creator: Akyurtlu, Ates & Akyurtle, Jale F.
Partner: UNT Libraries Government Documents Department

FURNACE INJECTION OF ALKALINE SORBENTS FOR SULFURIC ACID CONTROL

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

OXIDATION OF MERCURY ACROSS SCR CATALYSTS IN COAL-FIRED POWER PLANTS BURNING LOW RANK FUELS

Description: This is the seventh Quarterly Technical Report for DOE Cooperative Agreement No: DE-FC26-03NT41728. The objective of this program is to measure the oxidation of mercury in flue gas across SCR catalyst in a coal-fired power plant burning low rank fuels using a slipstream reactor containing multiple commercial catalysts in parallel. The Electric Power Research Institute (EPRI) and Argillon GmbH are providing co-funding for this program. This program contains multiple tasks and good progress is being made on all fronts. During this quarter, a model of Hg oxidation across SCRs was formulated based on full-scale data. The model took into account the effects of temperature, space velocity, catalyst type and HCl concentration in the flue gas.
Date: October 29, 2004
Creator: Senior, Constance
Partner: UNT Libraries Government Documents Department

Investigation of mixed metal sorbent/catalysts for the simultaneous removal of sulfur and nitrogen oxides

Description: Simultaneous removal of SO{sub 2} and NO{sub x} using a regenerable solid sorbent will constitute an important improvement over the use of separate processes for the removal of these two pollutants from stack gases and possibly eliminate several shortcomings of the individual SO{sub 2} and NO{sub x} removal operations. The work done at PETC and the DOE-funded investigation of the investigators on the sulfation and regeneration of alumina-supported cerium oxide sorbents have shown that they can perform well at relatively high temperatures (823-900 K) as regenerable desulfurization sorbents. Survey of the recent literature shows that addition of copper oxide to ceria lowers the sulfation temperature of ceria down to 773 K, sulfated ceria-based sorbents can function as selective SCR catalysts even at elevated temperatures, SO{sub 2} can be directly reduced to sulfur by CO on CuO-ceria catalysts, and ceria-based catalysts may have a potential for selective catalytic reduction of NO{sub x} by methane. These observations indicate a possibility of developing a ceria-based sorbent/catalyst which can remove both SO{sub 2} and NO{sub x} from flue gases within a relatively wide temperature window, produce significant amounts of elemental sulfur during regeneration, and use methane for the selective catalytic reduction of NO{sub x}. The objective of this research is to conduct kinetic and parametric studies of the selective catalytic reduction of NO{sub x} with NH{sub 3} and CH{sub 4} over alumina-supported cerium oxide and copper oxide-cerium oxide sorbent/catalysts; investigate SO{sub 2} removal at lower temperatures by supported copper oxide-cerium oxide sorbents; and investigate the possibility of elemental sulfur production during regeneration with CO or with CH{sub 4}-air mixtures.
Date: March 31, 1999
Creator: Akyurtlu, A. & Akyurtlu, J.F.
Partner: UNT Libraries Government Documents Department

DEVELOPMENT OF IMPROVED CATALYSTS FOR THE SELECTIVE CATALYTIC REDUCTION OF NITROGEN OXIDES WITH HYDROCARBONS

Description: Significant work has been done by the investigators on the cerium oxide-copper oxide based sorbent/catalysts for the combined removal of sulfur and nitrogen oxides from the flue gases of stationary sources. A relatively wide temperature window was established for the use of alumina-supported cerium oxide-copper oxide mixtures as regenerable sorbents for SO{sub 2} removal. Evaluation of these sorbents as catalysts for the selective reduction of NO{sub x} gave promising results with methane. Since the replacement of ammonia by methane is commercially very attractive, in this project, it was planned to investigate the effect of promoters on the activity and selectivity of copper oxide/cerium oxide-based catalysts and to obtain data on the reaction mechanism for the SCR with methane. The investigation of the reaction mechanism will help in the selection of promoters to improve the catalytic activity and selectivity of the sorbents in the SCR with methane. This will result in new catalyst formulations. The last component of the project involves our industrial partner TDA Research, and the objective is to evaluate long- term stability and durability of the prepared sorbent/catalysts. In the second year of the project, the catalysts were investigated for their SCR activity with methane in a microreactor setup and also, by the temperature-programmed desorption (TPD) technique. The results from the SCR experiments indicated that manganese is a more effective promoter than rhodium on the supported copper oxide-ceria catalysts under study; the effectiveness of the promoter increases with the increase in Ce/Cu ratio. The TPD profiles of the unpromoted catalyst (Cu/Ce=3) is different than those promoted with 0.1% rhodium. In the current reporting period, the screening of the promoted catalysts were completed, sufficient amount of the selected catalysts were prepared and delivered to TDA for long term deactivation testing.
Date: January 28, 2003
Creator: Akyurlu, Dr. Ates & Akyurtlu, Dr. Jale F.
Partner: UNT Libraries Government Documents Department

Development of NOx Sensors for Heavy Vehicle Applications

Description: The primary gaseous pollutants (excluding CO{sub 2}) produced by combustion of low-sulfur diesel fuel oxides of nitrogen (NO{sub x}), carbon monoxide (CO), and hydrocarbons (C{sub y}H{sub z}). The last two of these can be readily ameliorated by an oxidation catalyst in the O{sub 2}-rich environment of diesel exhaust but NO{sub x} can not.[1] For this reason NO{sub x} remediation strategies such as selective catalytic reduction (SCR) [2, 3] and the lean NO{sub x} trap (LNT) [4, 5] are being actively pursued. The ideal implementation of these strategies would employ NO{sub x} sensors to control reagent injection in the case of SCR and trap regeneration in the case of LNT. Two different NO{sub x} sensors for this application are at or near commercialization: An amperometric NO{sub x} sensor developed by NGK [6] and a 'mixed potential' NO{sub x} sensor developed by Riken [7]. The NGK sensor works by passing the sampled exhaust through a series of two chambers. In the first chamber O{sub 2} is pumped from the exhaust and in the second, NO{sub x} is decomposed electrochemically and the current from this decomposition is measured in order to determine [NO{sub x}]. Since the NO{sub x} concentrations can be small, on the 10's of ppm levels, the currents produced by decomposing the NO{sub x} can be small and difficult to measure accurately. The Riken sensor functions by passing the exhaust over a 'conversion electrode' that converts the NO{sub x} to NO{sub 2}. This NO{sub 2} is then sensed by a mixed potential sensing element.[8-10] Researchers at Ford evaluated the NGK sensor and observed the above shortcoming (poor for low [NO{sub x}]) as well as others [11] (e.g., asymmetric response to NO vs. NO{sub 2}) and were unable to obtain samples of the Riken sensor. Therefore a CRADA was initiated between Ford ...
Date: November 6, 2006
Creator: Armstrong, T.R.; West, D. L. & Montgomery, F.C.
Partner: UNT Libraries Government Documents Department

EVALUATION OF MERCURY EMISSIONS FROM COAL-FIRED FACILITIES WITH SCR AND FGD SYSTEMS

Description: CONSOL Energy Inc., Research & Development (CONSOL), with support from the U.S. Department of Energy, National Energy Technology Laboratory (DOE) and the Electric Power Research Institute (EPRI), is evaluating the effects of selective catalytic reduction (SCR) on mercury (Hg) capture in coal-fired plants equipped with an electrostatic precipitator (ESP)--wet flue gas desulfurization (FGD) combination or a spray dryer absorber--fabric filter (SDA-FF) combination. In this program CONSOL is determining mercury speciation and removal at 10 coal-fired facilities. The objectives are (1) to evaluate the effect of SCR on mercury capture in the ESP-FGD and SDA-FF combinations at coal-fired power plants, (2) evaluate the effect of catalyst degradation on mercury capture; (3) evaluate the effect of low load operation on mercury capture in an SCR-FGD system, and (4) collect data that could provide the basis for fundamental scientific insights into the nature of mercury chemistry in flue gas, the catalytic effect of SCR systems on mercury speciation and the efficacy of different FGD technologies for mercury capture. This document, the seventh in a series of topical reports, describes the results and analysis of mercury sampling performed on a 1,300 MW unit burning a bituminous coal containing three percent sulfur. The unit was equipped with an ESP and a limestone-based wet FGD to control particulate and SO2 emissions, respectively. At the time of sampling an SCR was not installed on this unit. Four sampling tests were performed in September 2003. Flue gas mercury speciation and concentrations were determined at the ESP outlet (FGD inlet), and at the stack (FGD outlet) using the Ontario Hydro method. Process stream samples for a mercury balance were collected to coincide with the flue gas measurements. The results show that the FGD inlet flue gas oxidized:elemental mercury ratio was roughly 2:1, with 66% oxidized mercury and 34% elemental ...
Date: November 1, 2005
Creator: Withum, J.A.; Tseng, S.C. & Locke, J.E.
Partner: UNT Libraries Government Documents Department

Advanced CIDI Emission Control System Development

Description: Ford Motor Company, with ExxonMobil and FEV, participated in the Department of Energy's (DOE) Ultra-Clean Transportation Fuels Program with the goal to develop an innovative emission control system for light-duty diesel vehicles. The focus on diesel engine emissions was a direct result of the improved volumetric fuel economy (up to 50%) and lower CO2 emissions (up to 25%) over comparable gasoline engines shown in Europe. Selective Catalytic Reduction (SCR) with aqueous urea as the NOx reductant and a Catalyzed Diesel Particulate Filter (CDPF) were chosen as the primary emission control system components. The program expected to demonstrate more than 90% durable reduction in particulate matter (PM) and NOx emissions on a light-duty truck application, based on the FTP-75 drive cycle. Very low sulfur diesel fuel (<15 ppm-wt) enabled lower PM emissions, reduced fuel economy penalty due to the emission control system and improved long-term system durability. Significant progress was made toward a durable system to meet Tier 2 Bin 5 emission standards on a 6000 lbs light-duty truck. A 40% reduction in engine-out NOx emissions was achieved with a mid-size prototype diesel engine through engine recalibration and increased exhaust gas recirculation. Use of a rapid warm-up strategy and urea SCR provided over 90% further NOx reduction while the CDPF reduced tailpipe PM to gasoline vehicle levels. Development work was conducted to separately improve urea SCR and CDPF system durability, as well as improved oxidation catalyst function. Exhaust gas NOx and ammonia sensors were also developed further. While the final emission control system did not meet Tier 2 Bin 5 NOx after 120k mi of aging on the dynamometer, it did meet the standards for HC, NMOG, and PM, and an improved SCR catalyst was shown to have potential to meet the NOx standard, assuming the DOC durability could be improved ...
Date: May 31, 2006
Creator: Lambert, Christine
Partner: UNT Libraries Government Documents Department

Advanced Combustion Systems for Next Generation Gas Turbines

Description: Next generation turbine power plants will require high efficiency gas turbines with higher pressure ratios and turbine inlet temperatures than currently available. These increases in gas turbine cycle conditions will tend to increase NOx emissions. As the desire for higher efficiency drives pressure ratios and turbine inlet temperatures ever higher, gas turbines equipped with both lean premixed combustors and selective catalytic reduction after treatment eventually will be unable to meet the new emission goals of sub-3 ppm NOx. New gas turbine combustors are needed with lower emissions than the current state-of-the-art lean premixed combustors. In this program an advanced combustion system for the next generation of gas turbines is being developed with the goal of reducing combustor NOx emissions by 50% below the state-of-the-art. Dry Low NOx (DLN) technology is the current leader in NOx emission technology, guaranteeing 9 ppm NOx emissions for heavy duty F class gas turbines. This development program is directed at exploring advanced concepts which hold promise for meeting the low emissions targets. The trapped vortex combustor is an advanced concept in combustor design. It has been studied widely for aircraft engine applications because it has demonstrated the ability to maintain a stable flame over a wide range of fuel flow rates. Additionally, it has shown significantly lower NOx emission than a typical aircraft engine combustor and with low CO at the same time. The rapid CO burnout and low NOx production of this combustor made it a strong candidate for investigation. Incremental improvements to the DLN technology have not brought the dramatic improvements that are targeted in this program. A revolutionary combustor design is being explored because it captures many of the critical features needed to significantly reduce emissions. Experimental measurements of the combustor performance at atmospheric conditions were completed in the first phase of ...
Date: January 1, 2006
Creator: Haynes, Joel; Janssen, Jonathan; Russell, Craig & Huffman, Marcus
Partner: UNT Libraries Government Documents Department