氨基酸盐吸收剂对煤层气中CO2的去除特性

Removal Characteristics of Amino Acid Salt Absorbents on Carbon Dioxide from Coalbed Methane

为探究氨基酸盐吸收剂对煤层气中CO2的去除特性,利用循环式吸收和再生实验,分别对3种由氨基酸盐与甲基二乙醇胺(MDEA)组成的混合吸收剂,进行煤层气CO2吸收和解吸特性研究,并与相应的单一氨基酸盐及传统的胺类吸收剂单乙醇胺(MEA)进行比较。结果表明,单一氨基酸盐吸收剂与MEA具有相似的CO2吸收能力;添加MDEA后,氨基酸盐对CO2的吸收和解吸性能得到明显提升;由于精氨酸分子中特殊的氨基基团,精氨酸钾(KARG)与MDEA的混合溶液获得了最高的CO2初始吸收速率(1.13E-03mol·L^-1 s^-1)、最高的初始解吸速率(7.70E-04mol·L^-1 s^-1)及最高的净循环负荷(0.714mol/mol)。综合考虑CO2去除性能和吸收剂成本,混合吸收剂KARG+MDEA在煤层气纯化方面具有广阔的应用前景。

To investigate the removal characteristics of amino acid salt absorbents on CO2 from coalbed methane(CBM),cyclic absorption and regeneration experiments were conducted to study the effects of mixed absorbent on the absorption and desorption performances of CO2 in CBM.mixed absorbent was composed of three different amino acid salts and methyldiethanolamine(MDEA).Comparation was conducted with their corresponding amino acid salts and conventional amine absorbent monoethanolamine(MEA).Result showed that single amino acid salt and MEA had similar CO2 absorption capabilities.Both CO2 absorption and desorption performances were improved obviously by blending MDEA additives into amino acid salt.Due to the special amino groups in arginine molecule,the mixed absorbent containing potassium arginine(KARG)solution and MDEA additive achieved the highest CO2 initial absorption(1.13 E-03 mol·L^-1 s^-1)and the higest desorption rate(7.70 E-04 mol·L^-1 s^-1)and the highest CO2 net cyclic capacity(0.714 mol/mol).Taking CO2 removal performance and absorbent cost into consideration,the mixed absorbent KARG+MDEA had a broad application prospect in CBM purification.