氨法吸收CO_2过程的传热/传质及反应模型研究  

Heat/Mass Transfer and Reaction Models for CO_2 Absorption by Aqueous Ammonia

作　　者：张民楷[1] 郭印诚[1] 

机构地区：[1]清华大学工程力学系,北京市海淀区100084

出　　处：《中国电机工程学报》2014年第23期3836-3842,共7页Proceedings of the CSEE

基　　金：北京市科委科技计划项目(Z08040902950803)~~

摘　　要：以氨法吸收CO2过程为研究对象,针对气液两相之间传热/传质及反应模型的区别,对比了RK(rate-based,kinetic),RC(rate-based,chemistry),EK(equilibrium-based,kinetic)and EC(equilibrium-based,chemistry)4种模型对CO2吸收过程中CO2吸收速率、富液碳化度、出口NH3浓度等关键目标参数的预测能力。模拟结果显示,RK模型对氨法CO2吸收过程具有最佳的预测能力。引入Murphree效率可修正基于平衡的模型对气液两相间传热/传质的预测,但是需要考虑到Murphree效率因组分而异并能逐级改变的局限。通过对Kinetic反应模型中动力学反应的敏感性分析发现,氨法吸收二氧化碳的过程主要受下述反应控制:NH3+CO2+H2O→NH2COO-+H3O+。For the NH3-based CO2 absorption process, the predictive abilities of different models for the heat/mass transfer and chemical reactions between the vapor and liquid phases were compared. The RK （rate-based, kinetic）, RC （rate-based, chemistry）, EK （equilibrium-based, kinetic）, and EC （equilibrium-based, chemistry） models were determined. The CO2 absorption rate, CO2 loading of the rich solvent, and NH3 concentration in the exit gas predicted by these models were obtained by process simulations. Simulation results show that the RK model has the best predictive ability for the NHa-based CO2 absorption process. Introducing the Murphree efficiency can amend the heat/mass transfer rates between the vapor and liquid phases predicted by the equilibrium-based model, but the limitation that the Murphree efficiency differs from components and stages should be considered when introducing this efficiency. Through sensitive analysis of the kinetic reactions, it is found that the NH3-based CO2 absorption process is mainly determined by the reaction of NH3＋CO2＋H2O→NH2COO-＋H30＋.

关 键 词：传热 传质模型 反应模型 CO2吸收 氨水 Murphree效率 

分 类 号：X701[环境科学与工程—环境工程]