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CERAMIC MEMBRANE ENABLING TECHNOLOGY FOR IMPROVED IGCC EFFICIENCY

Description: This quarterly technical progress report will summarize work accomplished for Phase 1 Program during the quarter April to June 2002. In task 1 improvements to the membrane material have shown increased flux, stability and strength. In task 2, composite development has demonstrated the ability to cycle membranes. In task 3, scale-up issues associated with manufacturing large elements have been identified and are being addressed. The work in task 4 has demonstrated that composite OTM elements can produce oxygen at greater than 95% purity after 10 thermal and pressure cycles. In task 5 the multi-tube OTM reactor has been operated and produced oxygen.
Date: August 1, 2002
Creator: Prasad, Ravi
Partner: UNT Libraries Government Documents Department

OXYGEN ENHANCED COMBUSTION FOR NOx CONTROL

Description: This quarterly technical progress report will summarize work accomplished for the Program through the ninth quarter April-June 2002 in the following task areas: Task 1--Oxygen Enhanced Combustion, Task 2--Oxygen Transport Membranes, Task 3--Economic Evaluation and Task 4--Program Management. The program is proceeding in accordance with the objectives for the third year. Full-scale testing using the Industrial Boiler Simulation Facility (ISBF) at Alstom Power was completed. The pilot scale experiments to evaluate the effect of air preheat and transport air stoichiometric ratio (SR) on NOx emissions were conducted at the University of Utah. Combustion modeling activities continued with full-scale combustion test furnace simulations. An OTM element was tested in Praxair's single tube high-pressure test facility and two thermal cycles were completed. PSO1d elements of new dimension were tested resulting in a lower flux than previous PSO1d elements of different dimensions, however, no element deformation was observed. Economic evaluation has confirmed the advantage of oxygen-enhanced combustion. Two potential host beta sites have been identified and proposals submitted.
Date: August 1, 2002
Creator: Thompson, David R.; Bool, Lawrence E. & Chen, Jack C.
Partner: UNT Libraries Government Documents Department

OXYGEN TRANSPORT CERAMIC MEMBRANES

Description: In the present quarter, oxygen transport perovskite ceramic membranes are evaluated for strength and fracture in oxygen gradient conditions. Oxygen gradients are created in tubular membranes by insulating the inner surface from the reducing environment by platinum foils. Fracture in these test conditions is observed to have a gradient in trans and inter-granular fracture as opposed to pure trans-granular fracture observed in homogeneous conditions. Fracture gradients are reasoned to be due to oxygen gradient set up in the membrane, variation in stoichiometry across the thickness and due to varying decomposition of the parent perovskite. The studies are useful in predicting fracture criterion in actual reactor conditions and in understanding the initial evolution of fracture processes.
Date: July 1, 2002
Creator: Bandopadhyay, Dr. Sukumar & Nagabhushana, Dr. Nagendra
Partner: UNT Libraries Government Documents Department

OXYGEN ENHANCED COMBUSTION FOR NOx CONTROL

Description: This quarterly technical progress report will summarize work accomplished for the Program in the seventh quarter October-December 2001 in the following task areas: Task 1 - Oxygen Enhanced Combustion, Task 2 - Oxygen Transport Membranes, Task 3 - Economic Evaluation and Task 4 - Program Management. Computational fluid dynamic (CFD) modeling of oxygen injection strategies was performed during the quarter resulting in data that suggest the oxygen injection reduces NOx emissions while reducing LOI. Pilot-scale testing activities concluded at the University of Utah this quarter. Testing demonstrated that some experimental conditions can lead to NOx emissions well below the 0.15 lb/MMBtu limit. Evaluation of alternative OTM materials with improved mechanical properties continued this quarter. Powder procedure optimization continued and sintering trial began on an element with a new design. Several OTM elements were tested in Praxair's single tube high-pressure test facility under various conditions. A modified PSO1d element demonstrated stable oxygen product purity of >98% and oxygen flux of 68% of target. Updated test results and projected economic performance have been reviewed with the Utility Industrial Advisors. The economic comparison remains very favorable for O{sub 2} enhanced combustion. Discussions regarding possible Beta sites have been held with three other utilities in addition to the industrial advisors. Proposals will be prepared after the completion of full scale burner testing. Beta test cost estimating work has been initiated.
Date: January 1, 2002
Creator: Thompson, David R.; Bool, Lawrence E. & Chen, Jack C.
Partner: UNT Libraries Government Documents Department

COAL PARTICLE FLOW PATTERNS FOR O2 ENRICHED, LOW NOx BURNERS

Description: The year-end report summarizes the results of the series of experiments conducted to evaluate the effects of oxygen partial pressure on coal combustion. Specifically, the effects of oxygen partial pressure in the transport air stream on flame stability, flame standoff distance and overall NO{sub x} emissions were examined. A series of experiments were conducted to determine the effect of oxygen partial pressure in the transport air on flame stability and resultant NO{sub x} emissions. In summary, the oxygen partial pressure experiments revealed that: (1) Increasing oxygen partial pressure in the transport air stream produced stable attached flames that were otherwise detached, reducing NO{sub x} emissions due to formation of fuel-rich central core which favors reduction of fuel nitrogen to N{sub 2}. Flame attachment also prevents premixing of fuel and air. (2) The degree of oxygen enrichment necessary to produce attached flames decreased with increasing wall temperature. (3) Increasing oxygen partial pressure in the transport air stream had little effect on emissions for always-attached and always-detached flames. The lack of an effect for always-detached flames is attributed to the extensive pre-mixing that occurs prior to ignition and the limited impact oxygen enrichment of the small transport air stream has on the oxygen concentration of the premixed transport and combustion air streams. (4) Reducing the oxygen partial pressure through nitrogen dilution destabilizes flames leading to flame detachment or blowout. These destabilizing effects increase with decreasing furnace temperature. These results are consistent with published literature. (5) The temperature dependence of NO{sub x,i} for detached flames is approximately 3 times greater than for attached flames.
Date: September 30, 2002
Creator: Curtis, Jennifer Sinclair
Partner: UNT Libraries Government Documents Department