National Energy Technology Laboratory-Regional University Alliance (NETL-RUA), Morgantown, West Virginia 26507, United States.
ACS Appl Mater Interfaces. 2013 Sep 11;5(17):8670-7. doi: 10.1021/am402306s. Epub 2013 Aug 22.
Amino acid ionic liquids (AAILs) are potential green substitutes of aqueous amine solutions for carbon dioxide (CO2) capture. However, the viscous nature of AAILs greatly hinders their further development in CO2 capture applications. In this contribution, 1-ethyl-3-methylimidazolium lysine ([EMIM][Lys]) was synthesized and immobilized into a porous poly(methyl methacrylate) (PMMA) microsphere support for post-combustion CO2 capture. The [EMIM][Lys] exhibited good thermal stability and could be facilely immobilized into porous microspheres. Significantly, the [EMIM][Lys]-PMMA sorbents retained their porous structure after [EMIM][Lys] loading and exhibited fast kinetics. When exposed to CO2 at 40 °C, [EMIM][Lys]-PMMA sorbent exhibited the highest CO2 capacity compared to other counterparts studied and achieved a capacity of 0.87 mol/(mol AAIL) or 1.67 mmol/(g sorbent). The capture process may be characterized by two stages: CO2 adsorption on the surface of sorbent and CO2 diffusion into sorbent for further adsorption. The calculated activation energies of the two-stage CO2 sorption were 4.1 and 4.3 kJ/mol, respectively, indicating that, overall, the CO2 can easily adsorb onto this sorbent. Furthermore, multiple cycle tests indicated that the developed sorbents had good long-term stability. The developed sorbent may be a promising candidate for post-combustion CO2 capture.
氨基酸离子液体（AAILs）是替代水合胺溶液用于捕获二氧化碳（CO2）的潜在绿色替代品。然而，AAILs 的粘性极大地阻碍了它们在 CO2 捕获应用中的进一步发展。在本研究中，合成了 1-乙基-3-甲基咪唑赖氨酸([EMIM][Lys])并将其固定到多孔聚甲基丙烯酸甲酯（PMMA）微球载体中，用于捕集烟道气中的 CO2。[EMIM][Lys]表现出良好的热稳定性，并且可以容易地固定到多孔微球中。重要的是，[EMIM][Lys]-PMMA 吸附剂在负载[EMIM][Lys]后保留了其多孔结构，并表现出快速的动力学。当在 40°C 下暴露于 CO2 时，[EMIM][Lys]-PMMA 吸附剂与所研究的其他对应物相比表现出最高的 CO2 容量，达到 0.87 mol/（mol AAIL）或 1.67 mmol/（g 吸附剂）。捕获过程可分为两个阶段：CO2 在吸附剂表面的吸附和 CO2 向吸附剂内部的扩散以进行进一步吸附。两阶段 CO2 吸附的计算活化能分别为 4.1 和 4.3 kJ/mol，表明总体而言，CO2 很容易吸附到该吸附剂上。此外，多次循环测试表明，所开发的吸附剂具有良好的长期稳定性。所开发的吸附剂可能是烟道气 CO2 捕集的有前途的候选者。
