水蒸气对石灰石/白云石循环吸收CO_2能力影响

Influence of Steam on Ability of Limestone /Dolomite for Cyclic CO_2 Capture

利用自制能实现等温下热重测量的实验系统,研究了水蒸气对不同粒径范围（75~97μm,150~250μm,355~450μm）石灰石与白云石在循环煅烧/碳酸化过程中对CO2吸收能力的影响。结果表明,当不考虑水蒸气时,白云石对CO2的吸收能力要高于石灰石;而考虑水蒸气时,两者对CO2的吸收能力则相差不多。碳酸化阶段水蒸气的存在提高了钙基吸收剂对CO2的吸收能力,尤其对石灰石作用更加明显。如在20%水蒸气下,石灰石循环第8次对CO2的吸收能力为0.24 g/g,而无水蒸气时仅为0.18 g/g。实验结果表明：比较石灰石与白云石对CO2的循环吸收能力时,水蒸气是重要的影响因素。

The influence of steam on the ability of limestone/dolomite with various particle size （75 - 97 μm, 150 - 250μm, and 355 -450μ m） for cyclic CO2 capture in the process of calcinations/carbonation cyclic reactions was researched with a customized experimental system that can measure sample weight changes at constant temperature. It was found that the capacity of CO2 capture by dolomite is higher than limestone when the water vapor is not considered. However during the stage of carbonation the presence of steam can effectively improve the ability to absorb CO2 by calcined limestone. For example, the ability to absorb CO2 by limestone at the eighth cycle is 0. 24g/g and 0. 18g/g respectively for carbonation with 20% steam and no steam. The abilities to absorb CO2 are similar in both when considering the presence of water vapor. Experimental result shows that to compare the ability to absorb CO2 by limestone and dolomite in the process of calcination/carbonation cyclic reactions the presence of steam should be considered.