自然型氨基酸及其钾盐的 CO2吸收和再生特性

在CO2吸收过程中,选择具有不挥发和不发生氧化降解特性的氨基酸盐吸收剂有助于降低吸收剂损失和减轻环境污染风险,故本研究以CO2吸收速率和再生速率为指标,对L-精氨酸和精氨酸钾（PA）吸收剂的CO2吸收性能和常压下热再生性能进行了实验分析,并研究了吸收剂质量分数、反应温度及吸收-再生循环次数对CO2吸收特性的影响,同时还与乙醇胺（MEA）、二乙醇胺（DEA）和三乙醇胺（TEA）进行了对比分析.结果表明,在实验的质量分数范围内,PA具有最高的CO2吸收速率和吸收能力,分别为24.5×10-3mol.（L.min）-1和1.99 mol.mol-1,比相同质量分数的MEA高2.1%和290.2%.温度影响结果表明,40℃时PA和MEA的CO2吸收速率均高于其他实验温度.相同再生条件下,PA的贫液CO2负荷要略高于MEA,但PA的再生程度可达72.8%,比MEA高19%.同时,3次＂吸收-再生＂循环之后,10%PA的CO2吸收能力仍可保持在1.03mol.mol-1,比10%MEA高255.2%.实验结果也表明,L-精氨酸具有较强的CO2吸收能力,其CO2吸收速率与同质量分数的DEA可比.

CO2 Absorption and Regeneration Performance of a Natural Amino Acid and Its Potassium Salt

In order to decrease the solvent loss due to amine volatilization and oxidative degradation and reduce the risk of environmental pollution resulting from amine volatilization, amino acid salts with negligible volatility and better resistance to oxidative degradation may be considered as the alternative during the course of CO2 capture. So, experimental study on CO2 absorption and regeneration characteristics of L-arginine and potassium argininate (PA) was put forward in this study based on the CO2 absorption rate and heating regeneration rate at ambient pressure. And the influences of absorbent mass concentration, reaction temperature and absorption-regeneration cycles on CO2 absorption performance of L-arginine and PA were also investigated, which were used to compare with the typical absorbents including monoethanolamine (MEA), diethanolamine (DEA) and triethanolamine (TEA). Results showed that among all the five absorbents, PA had the highest CO2 absorption rate of 24.5 x 10(-3) mol x (L x min)(-1) and CO2 loading capacity of 1.99 mol x mol(-1), which were 2.1% and 290.2% higher than MEA with the same mass concentration, respectively. The results also showed that CO2 absorption rate of PA and MEA at 40 degrees C was the highest compared to other temperatures. In addition, although CO2 loading of lean PA solution was slightly higher than that of MEA under the same regeneration conditions, 72.8% CO2 in the rich PA solution can be released, which is 19% higher than that of MEA. After three absorption-regeneration cycles, CO2 absorption capacity of 10% PA was found to be approximate 1.03 mol x mol(-1), which is 255.2% higher than MEA. Furthermore, L-arginine was found to have the stronger CO2 absorption capacity, and its CO2 absorption rate may be comparable to DEA with the same mass concentration.