INVESTIGATION OF MULTI-CYCLE PERFORMANCE OF CHEMICAL LOOPING GASIFICATION OF BIOMASS CHAR USING Fe-Ni BIMETALLIC OXYGEN CARRIER UNDER DIFFERENT ATMOSPHERES

摘要

Chemical looping gasification (CLG) is a novel gasificationrntechnology, which derives from chemical looping combustion (CLC).rnIt is achieved by oxygen carrier circulating between fuel reactor andrnair reactor to provide oxygen and heat source needed for fuelrngasification. The target product in the CLG process is synthesis gasrnrather than heat for the CLC process due to the low ratio of fuel tornoxygen carrier. In the previous work, the feasibility of biomass charrnwith NiO-modified oxygen carrier was investigated. Moderate carbonrnconversion was obtained during the process of char CLG, which wasrnobvious higher than that of char carbonization due to the presence ofrnoxygen carrier. Although a high temperature was maintained, biomassrnchar can not be fully converted because of the deficiency of oxygenrnsource. Hence, the objective of this work is to investigate thernreactivity of biomass char with Fe-Ni bimetallic oxygen carrier underrnCO2/H2O atmosphere with relative low temperature. Moreover, thernmulti-cycle performance of bimetallic oxygen carrier wasrnemphasized investigated. In the present work, continuous CLG ofrnbiomass char was realized through the switch of gas (Ar/CO_2/H_2O orrnAir) in a fixed bed reactor. The fresh and reacted oxygen carrierrnsamples were characterized using an X-ray diffractometer (XRD), Xrayrnphotoelectron spectroscopy (XPS), scanning electron microscopyrn(SEM) and pore size analyser.