Engineering Development of Coal-Fired High-Performance Power Systems

The concept uses a pyrolyzation process to convert coal into fuel gas and char. The char is fired in a High Temperature Advanced Furnace (HITAF). It is a pulverized fuel- fired boiler/ air heater where steam and gas turbine air are indirectly heated. The fuel gas generated in the pyrolyzer is then used to heat the gas turbine air further before it enters the gas turbine.   The project is currently in Phase 2 which includes engineering analysis, laboratory testing and pilot plant testing. Research and development is being done on the HIPPS systems that are not commercial or being developed on other projects. Pilot plant testing of the pyrolyzer subsystem and the char combustion subsystem are being done separately, and then a pilot plant with a more integrated HIPPS arrangement will be tested.   The High Performance Power System is a coal- fired, combined cycle power generating system that will have an efficiency of greater than 47 percent (HHV) with NOx and SOx less than 0.025 Kg/ GJ (0.06 lb/ MMBtu). This performance is achieved by combining a coal pyrolyzation process with a High Temperature Advanced Furnace (HITAF). The pyrolyzation process consists of a pressurized fluidized bed reactor which is operated at about 926 o C (1700 o F) at substoichiometric conditions. This process converts the coal into a low- Btu fuel gas and char. These products are then separated.   The char is fired in the HITAF where heat is transferred to the gas turbine compressed air and to the steam cycle. The HITAF is fired at atmospheric pressure with pulverized fuel burners. The combustion air is from the gas turbine exhaust stream. The fuel gas from the pyrolyzation process is fired in a Multi- Annular Swirl Burner (MASB) where it further heats the gas turbine air leaving the HITAF. This type of system results in very high efficiency with coal as the only fuel.   We are currently in Phase 2 of the project. In Phase 1, a conceptual plant design was developed and analyzed both technically and economically. The design was found to meet the project goals. The purpose of the Phase 2 work is to develop the information needed to design a prototype plant which would be built in Phase 3. In addition to engineering analysis and laboratory testing, the subsystems that are not commercial or being developed on other projects will be tested at pilot plant scale. The FWDC Second- Generation PFB pilot plant in Livingston, NJ, has been modified to test the pyrolyzer subsystem. The FWDC Combustion and Environmental Test Facility (CETF) in Dansville, NY, is being modified to test the char combustion system. When these tests are complete, a more integrated pilot plant will be tested.   During this Quarter, some modifications to the Livingston Pyrolyzer Pilot Plant were made and two more test runs were completed. All planned modes of operation with a jetting type of bubbling bed pyrolyzer have been completed. Data reduction for the first two test points is complete, but laboratory analysis for the last two runs is still in progress. The results so far indicate that this type of pyrolyzer will give performance that is acceptable for a HIPPS plant. The bubbling bed pyrolyzer has been run with beds of limestone and alternatively with sand beds. The coal input to the pyrolyzer has been pulverized coal in all cases.

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