Integrated solvent and process design for the reactive separation of CO_2 from flue gas

摘要

A model-based platform for assessing alternative designs and solvent blends for reactivernseparation processes is presented and applied to the problem of chemisorption of CO_2rnfrom flue gas with amine solvents. We combine state-of-the-art thermodynamics withrnrigorous process simulation techniques for this purpose. A rate-based model ofrnchemisorption units for CO_2 capture is implemented in the gPROMS modellingrnenvironment, using the statistical associating fluid theory for potentials of variable rangern(SAFT-VR)1 to represent mixture thermodynamics. Important features of our model arernthat both the reaction and phase equilibria are incorporated in the thermodynamicrnmodel, and as a result, enhancement factors are not required in the process model. Asrnreaction products are accounted for at the level of the thermodynamic model (from arnphysical perspective), the generation of reaction products or heat is consideredrnimplicitly in the mass and energy balances, further simplifying the model. We validaternour model using published pilot plant data, and subsequently apply this approach to therntreatment of a typical industrial scale flue gas stream and demonstrate how it can bernused to optimise simultaneously solvent composition and process operating conditions.