Abstract:

The presence of trace SO₂ in the flue gas of the power plant will affect the CO₂ sorption performance and cyclic characteristics of the solid amine sorbent. A solid amine-based CO₂ sorbent was prepared by a one-pot sol-gel process followed by supercritical drying (SCD) and the CO₂ sorption performance. Deactivation mechanism of the sorbent were studied by using fixed-bed reactor combined with infrared spectroscopy, BET and other test methods. The results show that the solid amine-based CO₂ sorbent has excellent CO₂ sorption performance and cyclic characteristics when the reaction temperature was 50℃. However, when the reaction atmosphere contains SO₂,the non-renewable sulphite or sulfate byproducts reduces the utilization rate of active amine sites, thus significantly decreasing the CO₂ adsorption capacity, and consequently, the cyclic characteristics were seriously affected. Besides, the pore distribution of sorbent also tends to small pore volume. Increasing the sorption temperature will enhance the CO₂ sorption competivity of the amine based sorbent.

Key words: CO₂ capture, solid amine based absorbent, sol-gel method, deactivation, SO₂

摘要：

燃煤电厂烟气中存在的微量SO₂对胺基CO₂固体吸附剂的碳酸化反应及循环特性有不利影响。利用固定床反应器，针对采用溶胶凝胶法制备的胺基CO₂固体吸附剂的碳酸化特性及其在含SO₂气氛下的失效规律进行了实验研究，并结合红外光谱、有机元素分析、BET等测试手段，研究其失效机理。结果表明，所制备的胺基CO₂固体吸附剂在反应温度50℃时具有较好的碳酸化反应特性和循环特性。当反应气氛中存在SO₂时，由于生成了不可再生的亚硫酸/硫酸盐类物质而导致胺基活性位损失，孔隙结构发生变化，影响了吸附剂的脱碳性能，但适当提高反应温度可提高吸附剂的碳酸化反应竞争性。

关键词: CO₂捕集, 固体胺基吸附剂, 溶胶凝胶法, 失效, SO₂