高灰煤小型流化床混合气催化气化研究

The experimental study on the Yangquan high-ash coal catalytic gasification with mixing-gas (air/steam) by using solid alkali (sodium hydroxide) or waste liquid of viscose fiber as the catalyst in a smallscale fluidized bed with 28mm i.d. was carried out. The loading saturation levels (LSL) of two catalysts in Yangquan high-ash coal are about 6%. Under the gasification temperature ranging from 830℃ to 900℃ and from 900℃ to 920℃, the apparent reaction order of Yangquan highash coal with respect to the unreacted carbon fraction approximates to 2/3 and 1/3 for the noncatalyst case, respectively. Also, the different values of apparent reaction order in the two temperature ranges are presented for the case with 3% solid alkali catalyst loaded. At the low temperature ranging from 830℃ to 860℃, the apparent reaction order of catalytic gasification is 1 since enough active carbon sites on the coal surface are formed during the catalytic gasification by solid alkali. But at the high temperature ranging from 860℃ to 920℃, the sodium carbonate produced by the reaction of solid alkali with carbon dioxide can be easily fused, transferred and redistributed, which affects the gasification reaction rate, and the apparent reaction order of catalytic gasification is reduced to 1/3.