Great efforts are underway to develop improved absorbents for post-combustion CO₂ capture. Regardless of the solvent composition, the absorbent can be represented by a series of sub-models for physicochemical properties. The purpose of this paper is to identify the solvent characteristics that play crucial roles in the total cost of CO₂ separation. Aqueous monoethanolamine (MEA) was selected as the reference solvent system, and a robust process model to describe its behavior was validated. The impact of various properties on the capture performance was evaluated separately via flowsheet simulations. The solvent viscosity, volatility, heat capacity, CO₂ solubility, enthalpy of solution, solvent strength and absorption kinetics have been identified to be important factors, that have however a combined effect on CO₂ separation cost. Compared with an optimized MEA-based capture plant, a lower capture cost of 52.19 €/ton CO₂ could be achieved with a low-volatile solvent. To show a clear target for further solvent development, sensitivity analyses of solvent properties were employed. Taking the assumed absorbent as a reference, an increase in CO₂ solubility, solvent strength or absorption kinetics, or a decrease in liquid volatility or viscosity can further improve solvent performance to some extent.

正在大力开发用于燃烧后CO ₂捕集的改进吸收剂。不论溶剂组成如何，吸收剂都可以用一系列物理化学性质的子模型表示。本文的目的是确定在CO ₂分离总成本中起关键作用的溶剂特性。选择单乙醇胺水溶液（MEA）作为参考溶剂系统，并验证了描述其行为的鲁棒过程模型。通过流程模拟分别评估了各种属性对捕获性能的影响。溶剂粘度，挥发性，热容量，CO ₂已经确定溶解度，溶液的焓，溶剂强度和吸收动力学是重要的因素，但是它们对CO ₂分离成本具有综合影响。与基于MEA的优化捕集装置相比，使用低挥发性溶剂可实现52.19€/吨CO ₂的较低捕集成本。为了显示出进一步开发溶剂的明确目标，采用了溶剂特性的敏感性分析。以假定的吸收剂为参考，CO ₂溶解度，溶剂强度或吸收动力学的增加或液体挥发性或粘度的降低可以在某种程度上进一步改善溶剂性能。