本文在深入分析含CO2混合气低温相变分离法特点与精馏特性的基础上,提出一种新型的CO2分离液化提纯一体化系统。该系统通过多级压缩,多级冷却与多级分离,可将混合气体中绝大部分CO2在较低能耗代价下以液态分离出来;同时,通过对分离出的粗CO2液体进行高压、近常温条件下的精馏,实现其低能耗提纯;最终实现以较低能耗分离回收cO2、而分离出的CO2纯度可达99.99%。本文研究成果为从具有较高CO2浓度的混合气体中分离回收CO2提供了新的思路与途径。
Based on the analysis of the cryogenic separation method and the distillation char- acteristics of the CO2 mixed gases, this paper puts forward a novel integration system with CO2 separation, liquefaction and purification simultaneously. In this system, most of CO2 can be separated from the mixed gases at a relatively higher condensing temperature through multi-stage cryogenic separation and compression, which can not only avoid the problem of CO2 freezing, but also reduce the compression work effectively. Moreover, in the novel system, by the high pressure and near atmospheric temperature distillation, the purity of CO2 product can reach a high level. Case study proves that for the novel system, the energy consumption of CO2 recovery can be 10%~60% less than that of traditional CO2 separation processes, and the CO2 purity can reach 99.99% or even higher. This paper provides a new idea and approach to separate and compress CO2 from the mixed gases with higher CO2 concentration with low energy consumption.