Optimization and control of CO2 capture using low transition temperature mixtures

Abstract

In this work, low transition temperature mixture (LTTM) tetrabutylammonium chloride-lactic acid (TBA-LA 1:2) is selected as the solvent for CO2 absorption. Firstly, the binary interaction parameters of TBA-LA 1:2-CO2 are calculated by the regression of experimental data which are obtained from literature, and some other binary interaction parameters, such as the binary interaction parameters of TBA-LA 1:2-N2 and TBA-LA 1:2-H2O, are predicted by COSMO-SAC model. And then, the design variables of CO2 absorption process are optimized using multi-objective generic algorithm (MOGA). The results show that the absorptive capacity of TBA-LA 1:2 is similar to monoethanolamine (MEA), but lower than that of ionic liquid 1-decyl-3-methyl imidazolium trifluoromethanesulfonate ([C10mim][TfO]). At last, the dynamic controllability of CO2 capture process is studied and an effective control structure is proposed, which works pretty well for the disturbances in both feed rate and feed composition.