Abstract:
Amine absorption (or amine scrubbing) is currently the most established method for CO2 capture; however, it has environmental shortcomings and is energy-intensive. Deep eutectic solvents (DESs) are an interesting alternative to conventional amines. Due to their biodegradability, lower toxicity and lower prices, DESs are considered to be \"more benign\" absorbents for CO2 capture than ionic liquids. In this work, the CO2 absorption capacity of choline-chloride/levulinic-acid-based (ChCl:LvAc) DESs was measured at different temperatures, pressures and stirring speeds using a vapour-liquid equilibrium rig. DES regeneration was performed using a heat treatment method. The DES compositions studied had ChCl:LvAc molar ratios of 1:2 and 1:3 and water contents of 0, 2.5 and 5 mol%. The experimental results showed that the CO2 absorption capacity of the ChCl:LvAc DESs is strongly affected by the operating pressure and stirring speed, moderately affected by the temperature and minimally affected by the hydrogen bond acceptor (HBA):hydrogen bond donator (HBD) molar ratio as well as water content. Thermodynamic properties for CO2 absorption were calculated from the experimental data. The regeneration of the DESs was performed at different temperatures, with the optimal regeneration temperature estimated to be 80 °C. The DESs exhibited good recyclability and moderate CO2/N2 selectivity.
摘要:
胺吸收(或胺洗涤)是目前最成熟的CO2捕获方法;然而,它具有环境缺陷,并且是能源密集型的。低共熔溶剂(DES)是常规胺的令人感兴趣的替代品。由于它们的生物降解性,更低的毒性和更低的价格,DES被认为是比离子液体更“良性”的CO2捕获吸收剂。在这项工作中,在不同温度下测量氯化胆碱/乙酰丙酸(ChCl:LvAc)DES的CO2吸收能力,压力和搅拌速度使用汽-液平衡钻机。使用热处理方法进行DES再生。所研究的DES组合物具有1:2和1:3的ChCl:LvAc摩尔比和0、2.5和5摩尔%的水含量。实验结果表明,ChCl:LvAcDES的CO2吸收能力受操作压力和搅拌速度的影响较大,受温度的影响中等,受氢键受体(HBA):氢键供体(HBD)摩尔比以及水含量的影响最小。从实验数据计算CO2吸收的热力学性质。DES的再生在不同的温度下进行,最佳再生温度估计为80°C。DES表现出良好的可回收性和中等的CO2/N2选择性。