abstract
- © 2016 Elsevier Ltd We propose a processing alternative for replacing the traditional and environmentally dangerous solvents (as monoethanolamine, diethanolamine) in the process of CO2 capture. We use a computer aided molecular design methodology for exploring the use of ionic liquids as solvents for CO2 capture. The optimization formulation is solved as a mixed-integer nonlinear programming problem, the objective is to obtain an optimal molecular structure of a particular class of ionic liquids for CO2 capture from a post-combustion gas stream. We use a subset of functional groups and anions, whose combination forms only certain kind of ILs that have the potential to solubilize CO2 and remove it from gas streams. The properties of ILs are estimated by group contributions methods and the equilibrium behaviour by empirical correlations. Moreover, recognizing the strong interactions between ionic liquids design and the processing system deployed to carried out the separation, a simultaneous optimal product and process design is also proposed. Moreover, we also propose a multiobjective optimization framework to deal with conflicting design objectives related to process economics and sustainability issues.