摘要: This study is to examine the changes in Cl volatilizations and chemical forms in NaCl-loaded Victorian brown coal during gasification in steam at 800 ℃ using Cl K-edge X-ray absorption near-edge structure (XANES) spectroscopy. The char samples were prepared in a novel one-stage fluidised-bed/fixed-bed quartz reactor at a fast heating rate. The samples were then collected and sealed in an argon-filled bag in order to minimise possible oxidation of char and Cl by air prior to analysis by XANES. Char-steam reactions were found to significantly affect the transformation of Cl, including the possible formation of chlorine-containing organic structures. On the other hand, volatile-char interactions during the gasification appeared to enhance the Cl retention and prevent the formation of organic chlorine compounds in chars.
摘要: The 15%(Co-Mn)/TiO2,(Co/Mn=1/6) catalyst was prepared using fusion procedure and studied for the conversion of synthesis gas to C2~4 olefins. The effects of calcination conditions and operation conditions such as the H2/CO molar feed ratio at different temperatures, gas hourly space velocity (GHSV) and total reaction pressure on the catalytic performance of catalyst were investigated. The stability of the catalyst during 150 h at optimal operation conditions (t=250 ℃ H2/CO=2/1, GHSV=1 500 h-1 and p=0.3 MPa) has been investigated. It is found that this catalyst is high stable for production C2~4 olefins. Characterizations of both precursors and calcined catalysts by powder X-ray diffraction, scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) specific surface area measurement and thermal analysis methods such as thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) show that the different preparation method influences the catalyst precursor structure and morphology.