Biomass Burning Technology Utilizing Circulating Fluidized Bed

CFB (Circulating Fluidized Bed) boiler appeared in the second half of the 1970 s. CFB boiler attracted attention that it was possible for the stable burning for the low quality fuel such as biomass and sludge which wasn't possible to burn in the conventional combustion.From the beginning of 1980 s, CFB boiler started to use for coal burning. It has a potential to use low quality coal which has high ash, high moisture, low volatile matter and low heating value. The low NOx and in-furnace DeSOx were admitted as a new technology for the environment load reduction in the coal burning plant. Therefore, as for the point of the cost performance, it got high evaluation and became the mainstream of the coal combustion. Moreover, the development of a large scale and a high efficiency plant has been progressing in the coal combustion. The large scale CFB boiler for the biofuel applied coal combustion technology has been also carried forward.With regard to the electricity generation used the city garbage, the high efficiency process is now required as a CO2, reduction technology. Biomass burning experience was applied to this, because city garbage has a high moisture and a high volatile matter like a biomass. The commercial plant to achieve this has already built and operated by Foster Wheeler from the beginning of 1997. In this process, the city garbage is converted to RDF (Refuse Derived Fuel), which is to recovery resources and also for the easy feeding and high performance combustion.The biomass utilization technologies, which use Foster Wheeler CFB, are not only the above-mentioned direct burning. The gasification technology has been developing from the early days. The development of atmospheric CFB gasifier has started from the beginning of 1980 s, and also pressurized gasifier was from the middle of 1989 s. Both technologies are in the commercial use stage.In the Foster Wheeler CFB technology used for the energy recovery with the high performance, the biomass and RDF direct burning, the atmospheric gasification for the biomass co-firing with coal and pressurized gasification for biomass IGCC (Integrated Gasification Combined Cycle) are presented in this paper.