钙法解吸并固定乙醇胺富液中CO2

针对醇胺类吸收剂富液中CO_2的解吸及后续处置所存在的不足,提出一种新型解吸方案——钙法.通过CO_2负荷试验和Ca(OH)_2投加量试验确定了该法理想处理负荷为0.84 mol·L-1,理想投加比例为C∶Ca=1∶1(摩尔比),此条件下反应15 min和30 min的解吸率达到52.17%和55.02%,这表明钙法矿化解吸乙醇胺富液中CO_2是可行的.在此基础上,进一步研究了pH、温度和搅拌强度对CO_2解吸固定效果的影响.试验结果表明,CO_2解吸率随着pH和搅拌强度的增加而增大,但当pH和搅拌强度增大到一定程度后,解吸率增长放缓甚至出现下降.较高的解吸温度尽管解吸率更大,但高温条件下无法达到矿化固定CO_2的目的.CO_2二次吸收负荷试验表明经钙法解吸后的MEA再生液具有良好的可重复使用性.

Desorption and mineralization of CO2 in monoethanolamine-rich solution by calcium method

A new process named calcium method, was proposed for the desorption and subsequent treatment of CO₂ in the monoethanolamine-rich solution.The ideal treatment loading for CO₂ and Ca(OH)₂ dosage of this method were 0.84 mol·L^-1and C:Ca=1:1(molar ratio), confirmed by loading test and dosing test, respectively. Under these conditions, the desorption rate of CO₂ was 52.17% and 55.02% at 15 min and 30 min, respectively, which indicated that the use of Ca(OH)₂ for desorption and mineralization of CO₂ in monoethanolamine-rich liquid was feasible. Subsequently, the effects of pH, temperature and agitation intensity on the desorption of CO₂ were investigated based on the reaction system above. The results showed that the desorption rate of CO₂ improved with the increase of pH and agitation intensity. However, when this two parameters increased to a certain high value, the desorption rate of CO₂ grew slowly or even declined. With rising the desorption temperature, the desorption rate increased, but the purposes of mineralization and fixture of CO₂ can not be achieved when the temperature was high. The secondary CO₂ absorption loading test showed that the MEA regeneration solution desorbed by calcium method had good reproducibility.