Fluidized bed: Projects and technology. FACT-Volume 19

AFBC boilers in the 100 to 250 MWe range are now being commercially applied as an alternative, coal-based power generating option. These boilers are capable of supporting the latest steam turbine conditions in pressure, temperature, and reheat conditions. The inherent emissions control, fuel flexibility, and competitive costs are reasons for many of the more recent AFBC plants. Fuel selection is a major decision for the power engineer. It is the single largest item in the power plant operating budget and has a major effect on power plant economics. AFBC technology has gained a reputation for burning almost anything. Any specific unit must, however, be suitable for the application. Plant systems and the AFBC boiler itself are dependent upon an accurate assessment of the fuel, sorbent, and bed material. To a large extent, they establish plant design requirements and the types of systems/features that are provided. An early analysis of the combustion and handling characteristics of the plant`s fuel, sorbent, and bed material should be completed. In advanced PFBC boilers, coal is pyrolyzed at pressure and the remaining char is burned in either an AGVC or PFBC boiler. The fuel gas produced is burned to raise the process flue gas tomore » higher operating temperatures. This increases the plants efficiency. It is estimated that this combined cycle will achieve heat rates as low as 7500 Btu/kWh. The papers in this volume describe recent AFBC and PFBC projects. They include applications fueled by coal and petroleum coke. The authors provide a glimpse of how AFBC technology is being commercially applied and the future prospects for PFBC technology.« less