基于DEEA/MEA两相吸收剂的15万t/年烟气CO_(2)捕集工艺模拟和技术经济分析

Process Simulation and Techno-economic Analysis on 150000t/year CO_(2) Chemical Absorption Process From Flue Gas Based on DEEA/MEA Biphasic Solvent

能耗高和冷却水耗大是目前燃烧后烟气CO_(2)化学吸收技术的瓶颈。两相吸收剂因其吸收CO_(2)后自发液液分相,富集CO_(2)于一相而大幅降低再生能耗,是较为有前景的CO_(2)吸收新技术。文中以50%二乙氨基乙醇(diethylaminoethanol,DEEA)/25%乙醇胺(monoethanolamine,MEA)为新型两相吸收剂,在Aspen Plus平台建立15万t/年烟气CO_(2)捕集工艺模型。基于实验数据,建立DEEA的非随机两流体(electrolyte non-random two liquids,eNRTL)热力学模型,解决新型吸收剂物性缺乏的问题。结果表明,CO_(2)脱除率为90%的前提下,与MEA工艺相比,两相吸收工艺的再生能耗、溶液循环量和冷却水耗分别可降低31%、30%、17%,两相吸收工艺的最低再生能耗为2.69GJ/t CO_(2)。DEEA/MEA两相工艺的投资成本比MEA工艺降低10%,运行成本降低15%。模拟研究对两相吸收剂捕集CO_(2)工艺的工业设计有一定参考意义。

High energy consumption and large cooling water consumption are the bottlenecks of chemical absorption technology for carbon dioxide(CO_(2))capture from flue gas.Using the biphasic solvent for CO_(2) capture is a promising technology in significantly reducing the regeneration energy as the biphasic solvent enables phase separation spontaneously after CO_(2) absorption and CO_(2) is rich in one phase.This paper used an aqueous blend of diethylaminoethanol(DEEA,50%)and monoethanolamine(MEA,25%)as novel biphasic solvent,and built a 150000 t/year CO_(2) capture process on Aspen Plus.Based on experimental data,DEEA's electrolyte non-random two liquids(eNRTL)thermodynamic model was established to solve the problem of lack of physical properties.Results show that DEEA/MEA process shows can be reduced by 31%lower regeneration energy,30%lower solution circulation flux,and 17%lower water consumption than MEA process at 90%of CO_(2) removal efficiency.The lowest regeneration energy of DEEA/MEA process is 2.69 GJ/tCO_(2).The DEEA/MEA process has a 10%lower capital cost and a 15%lower operating cost than MEA process.The simulation results are of reference value for industrial design.