烟气CO2捕集热能梯级利用节能工艺耦合优化  

Coupling optimization of energy-saving technology for cascade utilization of flue gas CO2 capture system

作　　者：陆诗建[1,2] 高丽娟 王家凤 赵东亚 王鑫 朱全民[1] LU Shijian;GAO Lijuan;WANG Jiafeng;ZHAO Dongya;WANG Xin;ZHU Quanmin(School of Chemical Engineering,China University of Petroleum(East China),Qingdao 266580,Shandong,China;Sinopec Energy and Environmental Engineering Co.,Ltd.,Dongying 257026,Shandong,China)

机构地区：[1]中国石油大学(华东)化学工程学院,山东青岛266580 [2]中石化节能环保工程科技有限公司,山东东营257026

出　　处：《化工进展》2020年第2期728-737,共10页Chemical Industry and Engineering Progress

基　　金：国家重点研发计划（2017YFB0603304）

摘　　要：醇胺法捕集CO2技术是一种较成熟的CO2捕集技术,具有吸收速度快、脱除效果好等显著优点,但其操作费用高、解吸能耗大。本文以降低醇胺法捕集烟气中CO2系统再生能耗为出发点,对常规醇胺法捕集CO2工艺统进行了节能优化研究。在常规工艺流程基础上引入压缩式热泵节能技术,并利用AspenPlus软件建立了基于压缩式热泵技术的CO2捕集工艺流程模型。研究了压缩式热泵与机械蒸汽压缩回收(M VR)热泵、分流解吸、分布式换热、级间冷却4种节能工艺耦合,通过模拟计算与优化,结果说明了最佳节能工艺组合为“解吸塔压缩式热泵+贫液MVR热泵+分流解吸+级间冷却”耦合的CO2捕集工艺流程,当解吸塔顶气体分流比为0.25∶0.75、冷富液分流比为0.05∶0.95、级间冷却器位于吸收塔17块塔板位置、吸收塔输入冷量为-3.0GJ/h时,系统再生能耗最低,为2.533GJ/tCO2,相比常规有机胺工艺(再生能耗4.204GJ/tCO2)节能率39.748%。The alcohol-amine method is a mature CO2 capture technology,which has the advantages of high absorption speed and good removal effect,but its operation cost is high and desorption energy consumption is large.Therefore,based on reducing regeneration energy consumption of CO2 capture system in flue gas by amine method,the energy saving of conventional CO2 capture system by amine method was studied in this paper.Based on the energy-saving research of conventional amine CO2 process,the energy-saving technology of compressed heat pump was introduced,and the CO2 capture process model based on compressed heat pump technology was established by Aspen Plus software.The coupling of compressed heat pump with MVR heat pump,split-flow desorption,distributed heat transfer and inter-stage cooling was studied.By simulation and optimization,the optimal energy-saving process combination was finally obtained as CO2 capture process of“desorption tower compressed heat pump+lean-liquid MVR heat pump+split-flow desorption+inter-stage cooling”coupling.When the split-flow ratio of top gas of desorption tower was 1/3,the split-flow ratio of rich and cold liquid was 0.05.The inter-stage cooler was located on 17 trays of the absorption tower.When the input cooling capacity of the absorption tower was-3.0GJ/h,the regeneration energy consumption of the system was the lowest,which is 2.533GJ/t CO2.Compared with the conventional organic amine process,the energy saving rate was 39.748%.

关 键 词：CO2捕集 再生能耗 压缩式热泵 节能技术 模型 优化 

分 类 号：TQ413[化学工程]