作为新型CO2吸收剂的乙酸钙循环碳酸化特性

钙基吸收剂的循环煅烧/碳酸化反应是煤燃烧或气化过程中捕获CO2的有效途径。该文采用乙酸溶液调质石灰石的产物乙酸钙作为CO2的新型吸收剂，以解决石灰石经过多次循环煅烧/碳酸化反应后吸收CO2能力急剧衰减的问题。在煅烧/碳酸化反应器上，研究碳酸化温度和煅烧温度对乙酸钙循环碳酸化转化率的影响。结果表明：碳酸化温度在650~700 ℃时乙酸钙能获得很高的碳酸化转化率，经20次循环后转化率仍高达0.5，明显高于石灰石。在高浓度CO2气氛下，在较高的煅烧温度(920~1 050 ℃)时，乙酸钙仍能获得较高的碳酸化转化率。乙酸钙的抗烧结能力较石灰石更强。多次循环后乙酸钙煅烧后的比表面积和孔容均大于煅烧后的石灰石，且孔容分布和孔比表面积分布均优于煅烧后的石灰石。

The Cyclic Carbonation Characteristics of Calcium Acetate as a New CO2 Sorbent

The cyclic calcination/carbonation reaction of calcium-based sorbents is an effective approach for capturing CO2 from coal combustion and gasification processes. It was proposed that limestone modified with acetic acid solution, i.e. calcium acetate, acts as a new CO2 sorbent to solve the problem about sharp decay of carbonation conversion for limestone with the number of cycles. The effects of carbonation temperature and calcination temperature on carbonation conversions for calcium acetate were experimentally investigated in a calcination/carbonation reactor. The results show that the carbonation conversion for calcium acetate achieves great value at the carbonation temperature range from 650 to 700 ℃. The carbonation conversion for calcium acetate can reach 0.5 after 20 cycles which is much greater than that for limestone. Although calcium acetate is calcined at high calcination temperature (920-1050 ℃) and under high CO2 concentration atmosphere, it still achieves the great carbonation conversion. It indicates that the anti-sintering performance for calcium acetate is much better than that for limestone. Specific surface area and pore volume for calcined calcium acetate are higher than those for calcined limestone, as well as pore volume and pore area distributions for calcined calcium acetate are superior to those for calcined limestone after multiple cycles.