基于MEA的CO_2相变化吸收剂的开发

Development of MEA phase change absorbent

化学吸收法是碳捕集技术中最为成熟的技术之一,单乙醇胺(MEA)是最常用的化学吸收剂.然而由于MEA的解吸能耗较高,造成CO_2捕集成本居高不下.本文提出了一种利用盐析效应开发新型CO_2相变化吸收剂的方法,并开发了吸收剂组成为"MEA+叔丁醇+水"的新型CO_2相变化吸收剂.实验考察了不同配比下吸收剂的分相情况、循环负载量以及吸收剂的物理性质,并用气相容积法测定了40℃、0～0.5 MPa下,CO_2在相变化吸收剂中的溶解度.研究表明,MEA/叔丁醇相变化吸收剂的循环负载量最高为2.84 mol CO_2/kg,相比于30%MEA水溶液提高了40%,进入解吸塔的吸收剂体积降低了65%,有望大幅降低CO_2捕集能耗.

Chemical absorption using MEA is one of the most mature technologies for carbon capture. However, the huge energy consumption of MEA results in high CO2 capture costs. In this article, for the purpose of reducing the energy consumption, a new type of CO2 phase change absorbent was developed based on salting-out effect, which composed of MEA/tertiary butanol/H2O. The phase separation behavior, cyclic loading and the physical properties of this phase changing absorbent were investigated by rapid screening experiment, as well as the CO2 solubility under40 ℃ and 0–0.5 MPa. The results show that the optimal cyclic loading of the phase change absorbent is up to2.84 mol CO2/kg, which is 40% higher than that of the 30% MEA aqueous solution. The volume of the absorbent into desorber is reduced by 65%. Application of such phase change absorbers will be beneficial to reduce CO2 capture energy consumption.