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PUBLIC ABSTRACTGiven that fossil fuel fired power plants are among the largest and most concentrated producers of CO 2 emissions, recovery and sequestration of CO 2 from the flue gas of such plants has been identified as one of the primary means for reducing anthropogenic CO 2 emissions.In 2001, ALSTOM began a two-phase program to investigate the feasibility of various carbon capture technologies. This program is sponsored under a Cooperative Agreement from the US Department of Energy's National Energy Technology Laboratory.Phase I entailed a comprehensive study evaluating the technical feasibility and economics of alternate CO 2 capture technologies applied to Greenfield US coal-fired electric generation power plants. Thirteen cases, representing various levels of technology development, were evaluated. Seven cases represent coal combustion cases in CFB type equipment. Four cases represent Integrated Gasification Combined Cycle (IGCC) systems. Two cases represent advanced Chemical Looping systems. Details of this work have been reported by Marion, et al, (2003).One of the cases studied was the oxygen-fired circulating fluidized bed (CFB) concept. When fired with oxygen, the flue gas from the CFB contains over 70% CO 2 . This flue gas can be processed to produce over 90% CO 2 for sequestration or use in enhanced oil recovery (EOR). The Phase I study identified the O 2 -fired CFB as having a near term development potential.Phase II -which is the subject of this report -consisted of pilot-scale testing followed by a refined performance and economic evaluation of the oxygen-fired CFB concept. As a part of this workscope, ALSTOM modified its 9.9 MM-Btu/hr Multiuse Test Facility (MTF) pilot plant to operate with O 2 /CO 2 mixtures of up to 70 % O 2 by volume. Tests with coal and petroleum coke were conducted. The test objectives were to determine the impacts of oxygen firing on heat transfer, bed dynamics, potential agglomeration, and gaseous and particulate emissions. The test data was used to refine the design, performance, costs, and economic models developed in Phase-I for an O 2 -fired CFB with CO 2 capture.Key results from the MTF testing are summarized below.• The furnace was successfully operated on bituminous coal and petcoke in O 2 /CO 2 combustion mediums containing local oxygen enrichments of up to 70%. There was no evidence of particle agglomeration or defluidization in the furnace.• Because of the high CO 2 content of the flue gas, the furnace operated above 1650°F to ensure calcination of the limestone for sulfur capture. In regions where the temperature was much cooler, there was evidence of recarbonation.• Because of the high temperature, the sulfur emissions from the bituminous coal were higher than normal for the same limestone feed rate. For pet coke, the optimum temperature for sulfur capture is higher, so the oxygen-fired emissions were very low.• NO x emissions were lower with oxygen firing. This is due to the reduction in prompt NO x , and perhaps some reduction in thermal NO x and fuel NO x ....

PUBLIC ABSTRACTGiven that fossil fuel fired power plants are among the largest and most concentrated producers of CO 2 emissions, recovery and sequestration of CO 2 from the flue gas of such plants has been identified as one of the primary means for reducing anthropogenic (i.e., man-made) CO 2 emissions.In 2001, ALSTOM Power Inc. (ALSTOM) began a two-phase program to investigate the feasibility of various carbon capture technologies. This program was sponsored under a Cooperative Agreement from the US Department of Energy's National Energy Technology Laboratory (DOE).The first phase entailed a comprehensive study evaluating the technical feasibility and economics of alternate CO 2 capture technologies applied to Greenfield US coal-fired electric generation power plants. Thirteen One of the thirteen cases studied utilized an oxygen-fired circulating fluidized bed (CFB) boiler. In this concept, the fuel is fired with a mixture of oxygen and recirculated flue gas (mainly CO 2 ) -see schematic below. This combustion process yields a flue gas containing over 80 percent (by volume) CO 2 . This flue gas can be processed relatively easily to enrich the CO 2 content to over 96 percent for use in enhanced oil or gas recovery (EOR or EGR) or simply dried for sequestration. The Phase I study identified the O 2 -fired CFB as having a near term development potential, because it uses conventional commercial CFB technology and commercially available CO 2 capture enabling technologies such as cryogenic air separation and simple rectification or distillation gas processing systems. In the long term, air separation technology advancements offer significant reductions in power requirements, which would improve plant efficiency and economics for the oxygen-fired technology.The second phase consisted of pilot-scale testing followed by a refined performance and economic evaluation of the O 2 fired CFB concept. As a part of this workscope, ALSTOM modified its 3 MW th (9.9 MMBtu/hr) Multiuse Test Facility (MTF) pilot plant to operate with O 2 /CO 2 mixtures of up to 70 percent O 2 by volume. Tests were conducted with coal and petroleum coke. The test objectives were to determine the impacts of oxygen firing on heat transfer, bed dynamics, potential agglomeration, and gaseous and particulate emissions. The test data results were used to refine the design, performance, costs, and economic models developed in Phase-I for the O 2 -fired CFB with COMMERCIALIZATION DEVELOPMENT OF OXYGEN FIRED CFB FOR GREENHOUSE GAS CONTROL ALSTOM Power Inc.August 24, 2007 v CO 2 capture. Nsakala, Liljedahl, and Turek reported results from this study in 2004.ALSTOM identified several items needing further investigation in preparation for large scale demonstration of the oxygen-fired CFB concept, namely:• Operation and performance of the moving bed heat exchanger (MBHE) to avoid recarbonation and also for cost savings compared to the standard bubbling fluid bed heat exchanger (FBHE).• Performance of the back-end flash dryer absorber (FDA) for sulfur capture u...

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