The effect of alkali metals on efficiency of gas generation during fluidized bed biomass gasification process

• Main Authors: Tzu-Huan Peng, 彭子桓
• Other Authors: Chiou-Liang Lin
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/25963958196193247390

碩士 === 國立高雄大學 === 土木與環境工程學系碩士班 === 99 === The aim of this study determines the effects of agglomeration/defluidization in buble fluidized bed gasification process. The artificial biomass consisted alkai metals and alkaline earth metal to simulate the agglomeration/defluidization. The operating temperature, ER and S/B were considered in the gasification process. The defuilization time and the gas generation behavior (gas composition, gas yield, carbon conversion, heat value of gas and cold gas effiviency) were determined. The results indicate that increasing temperature and ER were promoted the gas yield and carbon conversin. And the high tempertuare also increased the rate of hydrogen in the syngas and the cold gas effiviency. So, the 1.5 S/B was the best parameter in this study. When the alkai metal was added into the artificial biomass, the gas composition, gas yield and carbon conversion were increased. The heat vale of gas and the cold gas effiviency were decreased with the 1.5 S/B. The potassium was better than sodium in the gas generation behavior. On other hand, increasing the concentration of the alkai metals could promote the rate of hydrogen in the syngas. However, it may increase the risk of agglomeration/defluidization. After the agglomeration/defluidization, the carbon coversion, the heat value of gas and cold gas effiviency were desreased. Addition of alkaline earth metal (Ca) not only could inhibit the agglomeration/defluidization, but also increase the rate of hydrogen in the syngas. This result shows that the gas generation behavior in buble fluidized bed gasification process is affected not only the alkai metals and alkaline earth metal but also the agglomeration/defluidization behavior.