Assessment of the state of the art of pressurized fluidized bed combustion systems

Abstract

This report was prepared at the request of the Tennessee Valley Authority (TVA) to clarify the development status of the pressurized fluidized bed combustor (PFBC) and to place in perspective the problems which are yet to be solved before commercialization of the concept is practical. The report is viewed as preliminary to a more complete and comprehensive work to be carried out during FY 1979. An evaluation of the PFBC concept cites potential advantages over atmospheric pressure fluidized bed combustors (AFBC) in the areas of combustion efficiency, sulfur retention, furnace design, power plant efficiency, and others. The key disadvantage of unproven hot gas cleanup and associated gas turbine technology is discussed in considerable detail. A survey of existing and developing PFBC experimental facilities is presented plus some results from the experimental programs. Recent design studies for full-sized PFBC power plants are reviewed with emphasis on key design parameters. Results for similar AFBC design studies are presented in contrast. The general conclusion drawn from this preliminary survey is that the potential advantages of the PRBC used in conjunction with a high-temperature (850/sup 0/C (1560/sup 0/F)) gas turbine will be difficult to realize due primarily to the formidable task of developing adequate hot gas cleanup and turbine systems, and due to the anticipated high cost of these systems.