Operational Characteristics of Biomass Circulating Fluidized Bed Gasifier
1. Zhejiang University of Water Resources and Electric Power, Hangzhou 310018, China;
2. Pyneo Company Limited, Hangzhou 311121, China;
3. Yihai Kerry Arawana Holdings Company Limited, Shanghai 200126, China
Abstract The commercial application of biomass circulating fluidized bed (CFB) gasifier in China is still in the initial stage, and there are few public reports about this kind of gasifier. It is significant for the commercial development of the biomass CFB gasifier to study its operational characteristics and control method. The commissioning test and operational adjustment of a biomass CFB gasifier in a rice mill factory of Jiangsu Province were introduced. Variations and control methods of the key parameters during the different operational stages of the gasifier, such as bed pressure, bed thickness, bed temperature, fluidizing air flow, recirculation air and steam flow, were analyzed. It showed that the bed pressure and bed thickness were mainly controlled by the coordination of feed rate and returning rate. The bed temperature was mainly controlled by the coordination of feed rate and fluidized air flow. During the combustion and gasification stages, the adjustment of air and biomass feeding should be in small quantity but high frequency. When convert the combustion stage to gasification, the feed should be fast in order to rapidly reduce the oxygen content in the flue gas, and rapidly convert to gasification. When normally shutdown, the feed reduction should be rapid in order to convert gasification to combustion for security reasons. These results provide certain guiding significance for the large-scale application of biomass circulating fluidized bed gasifier.
