Download or read book NOx EMISSIONS PRODUCED WITH COMBUSTION OF POWDER RIVER BASIN COAL IN A UTILITY BOILER written by and published by . This book was released on 1997 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this report is to estimate the NOx emissions produced when Powder River Basin (PRB) coal is combusted in a utility boiler. The Clean Air Act regulations specify NOx limits of 0.45 lb/mm Btu (Phase I) and 0.40 lb/mm Btu (Phase II) for tangentially fired boilers, and 0.50 lb/mm 13tu (Phase II) and 0.46 lb/mm Btu (Phase II) for dry-bottom wall-fired boilers. The Clean Air Act regulations also specify other limits for other boiler types. Compliance for Phase I has been in effect since January 1, 1996. Compliance for Phase II goes into effect on January 1, 2000. Emission limits are expressed as equivalent NO2 even though NO (and sometimes N2O) is the NOx species emitted during combustion. Regulatory agencies usually set even lower NOx emission limits in ozone nonattainment areas. In preparing this report, Western Research Institute (WRI) used published test results from utilities burning various coals, including PRB coal, using state-of-the art control technology for minimizing NOx emissions. Many utilities can meet Clean Air Act NOx emission limits using a combination of tight combustion control and low-NOx burners and by keeping furnaces clean (i.e., no slag buildup). In meeting these limits, some utilities also report problems such as increased carbon in their fly ash and excessive furnace tube corrosion. This report discusses utility experience. The theory of NOx emission formation during coal combustion as related to coal structure and how the coal is combusted is also discussed. From this understanding, projections are made for NOx emissions when processed PRB coal is combusted in a test similar to that done with other coals. As will be shown, there are a lot of conditions for achieving low NOx emissions, such as tight combustion control and frequent waterlancing of the furnace to avoid buildup of deposits.
Download or read book How Coal Properties Influence Emissions written by Robert M. Davidson and published by . This book was released on 2000 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Source assessment written by and published by . This book was released on 1981 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book METHANE De NOX for Utility PC Boilers written by Joseph Rabovitser and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall project objective is the development and validation of an innovative combustion system, based on a novel coal preheating concept prior to combustion, that can reduce NO{sub x} emissions to 0.15 lb/million Btu or less on utility pulverized coal (PC) boilers. This NO{sub x} reduction should be achieved without loss of boiler efficiency or operating stability, and at more than 25% lower levelized cost than state-of-the-art SCR technology. A further objective is to ready technology for full-scale commercial deployment to meet the market demand for NO{sub x} reduction technologies. Over half of the electric power generated in the U.S. is produced by coal combustion, and more than 80% of these units utilize PC combustion technology. Conventional measures for NOx reduction in PC combustion processes rely on combustion and post-combustion modifications. A variety of combustion-based NO{sub x} reduction technologies are in use today, including low-NO{sub x} burners (LNBs), flue gas recirculation (FGR), air staging, and natural gas or other fuel reburning. Selective non-catalytic reduction (SNCR) and selective catalytic reduction (SCR) are post-combustion techniques. NO{sub x} reduction effectiveness from these technologies ranges from 30 to 60% and up to 90-93% for SCR. Typically, older wall-fired PC burner units produce NO{sub x} emissions in the range of 0.8-1.6 lb/million Btu. Low-NO{sub x} burner systems, using combinations of fuel staging within the burner and air staging by introduction of overfire air in the boiler, can reduce NO{sub x} emissions by 50-60%. This approach alone is not sufficient to meet the desired 0.15 lb/million Btu NO{sub x} standard with a range of coals and boiler loads. Furthermore, the heavy reliance on overfire air can lead to increased slagging and corrosion in furnaces, particularly with higher-sulfur coals, when LNBs are operated at sub-stoichiometric conditions to reduce fuel-derived NOx in the flame. Therefore, it is desirable to minimize the need for overfire air by maximizing NO{sub x} reduction in the burner. The proposed combustion concept aims to greatly reduce NO{sub x} emissions by incorporating a novel modification to conventional or low-NO{sub x} PC burners using gas-fired coal preheating to destroy NO{sub x} precursors and prevent NO{sub x} formation. A concentrated PC stream enters the burner, where flue gas from natural gas combustion is used to heat the PC up to about 1500 F prior to coal combustion. Secondary fuel consumption for preheating is estimated to be 3 to 5% of the boiler heat input. This thermal pretreatment releases coal volatiles, including fuel-bound nitrogen compounds into oxygen-deficient atmosphere, which converts the coal-derived nitrogen compounds to molecular N{sub 2} rather than NO. Design, installation, shakedown, and testing on Powder River Basin (PRB) coal at a 3-million Btu/h pilot system at RPI's (Riley Power, Inc.) pilot-scale combustion facility (PSCF) in Worcester, MA demonstrated that the PC PREHEAT process has a significant effect on final O{sub x} formation in the coal burner. Modifications to both the pilot system gas-fired combustor and the PC burner led to NO{sub x} reduction with PRB coal to levels below 0.15 lb/million Btu with CO in the range of 35-112 ppmv without any furnace air staging.
Download or read book Reburning Technologies for the Control of Nitrogen Oxides Emissions from Coal Fired Boilers written by and published by DIANE Publishing. This book was released on with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NOx Control for Utility Boiler OTR Compliance written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Babcock & Wilcox Power Generation Group (B & W) and Fuel Tech, Inc. (Fuel Tech) teamed to evaluate an integrated solution for NO(subscript x) control comprised of B & W's DRB-4Z{reg_sign} low-NO(subscript x) pulverized coal (PC) burner technology and Fuel Tech's NO(subscript x)OUT{reg_sign}, a selective non-catalytic reduction (SNCR) technology, capable of meeting a target emission limit of 0.15 lb NO(subscript x)/106 Btu. In a previous project sponsored by the U.S. Department of Energy (DOE), promising results were obtained with this technology from large-scale testing in B & W's 100-million Btu/hr Clean Environment Development Facility (CEDF) which simulates the conditions of large coal-fired utility boilers. Under the most challenging boiler temperatures at full load conditions, NO(subscript x) emissions of 0.19 lb/106 Btu were achieved firing Powder River Basin coal while controlling ammonia slip to less than 5 ppm. At a 40 million Btu/hr firing rate, NO(subscript x) emissions were as low as 0.09 lb/106 Btu. Improved performance with this system was proposed for this new program with injection at full load via a convective pass multiple nozzle lance (MNL) in front of the superheater tubes or in the convective tube bank. Convective pass lances represent the current state-of-the-art in SNCR and needed to be evaluated in order to assess the full potential of the combined technologies. The objective of the program was to achieve a NO(subscript x) level below 0.15 lb/106 Btu (with ammonia slip of less than 5 ppm) in the CEDF using PRB coal and B & W's DRB-4Z{reg_sign} low-NO(subscript x) pulverized coal (PC) burner in combination with dual zone overfire air ports and Fuel Tech's NO(subscript x)OUT{reg_sign} System. Commercial installations of B & W's low-NO(subscript x) burner, in combination with overfire air ports using PRB coal, have demonstrated a NO(subscript x) level of 0.15 to 0.2 lb/106 Btu under staged combustion conditions. The proposed goal of the combustion system (no SNCR) for this project is a NO(subscript x) level at 0.15 lb/106 Btu. The NO(subscript x) reduction goal for SNCR is 25% from the low-NO(subscript x) combustion emission levels. Therefore, overall NO(subscript x) emissions would approach a level of 0.11 lb/106 Btu in commercial installation. The goals of the program were met. At 100% load, using the MNL for very low baseline NO(subscript x) (0.094 to 0.162 lb/106 Btu depending on burner stoichiometry), an approximately 25% NO(subscript x) reduction was achieved (0.071 to 0.124 lb/106 Btu) while maintaining NH3 slip less than 6.4 ppm. At 60% load, using MNL or only wall-injectors for very low baseline NO(subscript x) levels, more than 30% NO(subscript x) reduction was achieved. Although site specific economic evaluation is required for each unit, our economic evaluation of DRB-4Z{reg_sign} burner and SNCR for a 500 MW{sub e} plant firing PRB shows that the least cost strategy is low-NO(subscript x) burner and OFA at a cost of $210 to $525 per ton of NO(subscript x) removed. Installation of SNCR allows the utilities to sell more NO(subscript x) credit and it becomes economical when NO(subscript x) credit cost is more than $5,275 per ton of NO(subscript x).
Download or read book Emissions Reduction written by A. Tomita and published by Elsevier. This book was released on 2001-12-18 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past decade the topic of emissions reduction and control has remained an important area of research due to the enforcement of various Government policies in an attempt to minimize the impact on the environment. One area in which a great deal of research has been conducted to address this policy is NOx/SOx suppression. However, despite the progress that has been made over this time period, further research into the most effective method of reducing NOx/SOx emissions is still urgently required. In developed countries, a more stringent requirement in the level of emissions (such as is NOx/SOx component of less than 10ppm) will be enforced in the near future. Developing countries will also need a new technology that is effective and that is suited to each countries needs. Additional research and development efforts are thus necessary to meet such requirements. This compendium contains a collection of key papers themed around NOx/SOx emissions from combustion of hydrocarbon resources and the attempts to secure an efficient and effective method for reducing these emissions. These key papers are taken from the journals Fuel, Fuel Processing Technology and Progress in Energy and Combustion Science.
Download or read book Combustion Modification Effects on NOx Emissions from Gas Oil and Coal fired Utility Boilers written by Owen W. Dykema and published by . This book was released on 1978 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Barriers to Increased Coal Utilization written by Donald Bruce Peterson and published by . This book was released on 1985 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book written by and published by . This book was released on 1994 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the International Technical Conference on Coal Utilization Fuel Systems written by and published by . This book was released on 1998 with total page 1174 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solid Fuel Blending written by David Tillman and published by Elsevier. This book was released on 2012-03-21 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: Create affordable solid fuel blends that will burn efficiently while reducing the carbon footprint. Solid Fuel Blending Handbook: Principles, Practices, and Problems describes a new generation of solid fuel blending processes. The book includes discussions on such topics as flame structure and combustion performance, boiler efficiency, capacity as influenced by flue gas volume and temperature, slagging and fouling, corrosion, and emissions. Attention is given to the major types of combustion systems including stokers, pulverized coal, cyclone, and fluidized bed boilers. Specific topics considered include chlorine in one or more coals, alkali metals (e.g., K, Na) and alkali earth elements, and related topics. Coals of consideration include Appalachian, Interior Province, and Western bituminous coals; Powder River Basin (PRB) and other subbituminous coals; Fort Union and Gulf Coast lignites, and many of the off-shore coals (e.g., Adaro coal, an Indonesian subbituminous coal with very low sulfur; other off-shore coals from Germany, Poland, Australia, South Africa, Columbia, and more). Interactions between fuels and the potential for blends to be different from the parent coals will be a critical focus of this of the book. One stop source to solid fuel types and blending processes Evaluate combustion systems and calculate their efficiency Recognize the interactions between fuels and their potential energy output Be aware of the Environmental Aspects of Fuel Blending
Download or read book Investigation of Synergistic NOx Reduction from Cofiring and Air Staged Combustion of Coal and Low Ash Dairy Biomass in a 30 Kilowatt Low NOx Furnace written by Benjamin Daniel Lawrence and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Alternate, cost effective disposal methods must be developed for reducing phosphorous and nitrogen loading from land application of animal waste. Cofiring coal with animal waste, termed dairy biomass (DB), is the proposed thermo-chemical method to address this concern. DB is evaluated as a cofired fuel with Wyoming Powder River Basin (PRB) sub-bituminous coal in a small-scale 29 kW[subscript t] low NO[subscript x] burner (LNB) facility. Fuel properties, of PRB and DB revealed the following: a higher heating value of 29590 kJ/kg for dry ash free (DAF) coal and 21450 kJ/kg for DAF DB. A new method called Respiratory Quotient (RQ), defined as ratio of carbon dioxide moles to oxygen moles consumed in combustion, used widely in biology, was recently introduced to engineering literature to rank global warming potential (GWP) of fuels. A higher RQ means higher CO2 emission and higher GWP. PRB had an RQ of 0.90 and DB had an RQ of 0.92. For comparison purposes, methane has an RQ of 0.50. For unknown fuel composition, gas analyses can be adapted to estimate RQ values. The LNB was modified and cofiring experiments were performed at various equivalence ratios (phi) with pure coal and blends of PRB-DB. Standard emissions from solid fuel combustion were measured; then NO[subscript x] on a heat basis (g/GJ), fuel burnt fraction, and fuel nitrogen conversion percentage were estimated. The gas analyses yielded burnt fraction ranging from 89% to 100% and confirmed an RQ of 0.90 to 0.94, which is almost the same as the RQ based on fuel composition. At the 0.90 equivalence ratio, unstaged pure coal produced 653 ppm (377 g/GJ) of NO[subscript x]. At the same equivalence ratio, a 90-10 PRB:LADB blended fuel produced 687 ppm (397 g/GJ) of NO[subscript x]. By staging 20% of the total combustion air as tertiary air (which raised the equivalence ratio of the main burner to 1.12), NO[subscript x] was reduced to 545 ppm (304 g/GJ) for the 90-10 blended fuel. Analysis of variance showed that variances were statistically significant because of real differences between the independent variables (equivalence ratio, percent LADB in the fuel, and staging intensity). The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/151367
Download or read book Pilot scale Development of a Low NOx Coal fired Tangential System written by and published by . This book was released on 1981 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Joint Symposium on Stationary Combustion NOx Control written by and published by . This book was released on 1981 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings of the Joint Symposium on Stationary Combustion NOx Control written by J. Edward Cichanowicz and published by . This book was released on 1981 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Enhanced Combustion Low NOx Pulverized Coal Burner written by David Towle and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: For more than two decades, ALSTOM Power Inc. (ALSTOM) has developed a range of low cost, in-furnace technologies for NOx emissions control for the domestic U.S. pulverized coal fired boiler market. This includes ALSTOM's internally developed TFS 2000 firing system, and various enhancements to it developed in concert with the U.S. Department of Energy (DOE). As of 2004, more than 200 units representing approximately 75,000 MWe of domestic coal fired capacity have been retrofit with ALSTOM low NOx technology. Best of class emissions range from 0.18 lb/MMBtu for bituminous coals to 0.10 lb/MMBtu for subbituminous coals, with typical levels at 0.24 lb/MMBtu and 0.13 lb/MMBtu, respectively. Despite these gains, NOx emissions limits in the U.S. continue to ratchet down for new and existing (retrofit) boiler equipment. If enacted, proposed Clear Skies legislation will, by 2008, require an average, effective, domestic NOx emissions rate of 0.16 lb/MMBtu, which number will be reduced to 0.13 lb/MMBtu by 2018. Such levels represent a 60% and 67% reduction, respectively, from the effective 2000 level of 0.40 lb/MMBtu. Low cost solutions to meet such regulations, and in particular those that can avoid the need for a costly selective catalytic reduction system (SCR), provide a strong incentive to continue to improve low NOx firing system technology to meet current and anticipated NOx control regulations. In light of these needs, ALSTOM, in cooperation with the DOE, is developing an enhanced combustion, low NOx pulverized coal burner which, when integrated with ALSTOM's state-of-the-art, globally air staged low NOx firing systems, will provide a means to achieve less than 0.15 lb/MMBtu NOx at less than 3/4 the cost of an SCR with low to no impact on balance of plant issues when firing a high volatile bituminous coal. Such coals can be more economic to fire than subbituminous or Powder River Basin (PRB) coals, but are more problematic from a NOx control standpoint as existing firing system technologies do not provide a means to meet current or anticipated regulations absent the use of an SCR. The DOE/ALSTOM program performed large pilot scale combustion testing in ALSTOM's Industrial Scale Burner Facility (ISBF) at its U.S. Power Plant Laboratories facility in Windsor, Connecticut. During this work, the near-field combustion environment was optimized to maximize NOx reduction while minimizing the impact on unburned carbon in ash, slagging and fouling, corrosion, and flame stability/turn-down under globally reducing conditions. Initially, ALSTOM utilized computational fluid dynamic modeling to evaluate a series of burner and/or near field stoichiometry controls in order to screen promising design concepts in advance of the large pilot scale testing. The third and final test, to be executed, will utilize several variants of the best nozzle tip configuration and compare performance with 3 different coals. The fuels to be tested will cover a wide range of coals commonly fired at US utilities. The completion of this work will provide sufficient data to allow ALSTOM to design, construct, and demonstrate a commercial version of an enhanced combustion low NOx pulverized coal burner. A preliminary cost/performance analysis of the developed enhanced combustion low NOx burner applied to ALSTOM's state-of-the-art TFS 2000 firing system was performed to show that the burner enhancements is a cost effective means to reduce NOx.
