THE EFFECT OF ACETIFICATION ON CYCLIC CALCINATION CARBONATION CO2 CAPTURING WITH DOLOMITE

摘要

Calcium-based sorbents cyclic calcination-carbonation reaction (CCR) is an effective approach to CO2 sequestration for coal-fired power plants. It was proposed that calcium magnesium acetate (CMA) generated by acetification of dolomite acted as a new CO2 sorbent for long-term calcination-carbonation cycles, as well as the CCR of CMA was applied to the second generation PFBC-CC system. In a calcination-carbonation reactor system, the carbonation conversions for the calcined CMA, dolomite and limestone with the number of CCR cycles were experimentally investigated. The cyclic conversion for caclined CMA is much greater than that for calcined dolomite and limestone for the carbonation at 600 ℃-700 ℃ at the same calcination temperature. The carbonation conversion for calcined CMA achieves 0.6 even after 20 cycles, while that for dolomite after 18 cycles and limestone after 8 cycles reaches 0.28 and 0.32, respectively. CMA maintains the much greater conversion than dolomite and limestone for calcination from 920 ℃ to 1050 ℃. The acetification of dolomite improves the surface area and pore volume obviously, even after long series cycles. It indicates that CMA generated by acetification of dolomite is feasible as a new CO2 sorbent for long-term CCR and the technology of combining CMA CCR for CO2 capture with the second generation PFBC-CC system will be effective and promising.