Design and operation of a CFB gasification and power generation system for rice husk

A circulating fluidized bed (CFB) biomass gasification & power generation system (BGPG) for rice husk was designed and installed to provide power for a rice mill with a capacity of 150 t d(-1). The project has been operating in Putian Huaguang Miye Ltd., located in Fujian Province of China since the August of 1998. The system consists of a CFB gasifier, a gas cleaner (including an inertial separator, a cyclone separator, a venturi and two water scrubbers), and power generation subsystem (containing five parallel gas engines rated 200 kW each), in addition to a wastewater treatment system. It is found that the system can be operated stably within the temperature from 700degreesC to 850degreesC, and its optimal condition was reached when the workload is increased above 800 kW. The main performance indices are: capacity: 1500 kg h(-1), gasification efficiency: 65%, rice husk consumption: 1.7-1.9 kg kW h(-1), total efficiency: about 17%. The reliability of the BGPG system has been proven through two years of operation (about 10, 000 h). The total investment is 510 000 US$, the unit investment is 370 US$ kW(-1), the operation cost is 0.032 USS kW(-1), and the payback period is not more than two years. (C) 2002 Elsevier Science Ltd. All rights reserved.