Modelling of reactive separation processes: reactive absorption and reactive distillation

In the last years chemical process industries have shown permanently increasing interest in the development of reactive separation processes (RSP) combining reaction and separation mechanisms into a single, integrated unit. Such processes bring several important advantages among which are increase of reaction yield and selectivity, overcoming thermodynamic restrictions, e.g. azeotropes, and considerable reduction in energy, water and solvent consumption. Important examples of reactive separations are reactive distillation (RD) and reactive absorption (RA). Due to strong interactions of chemical reaction and heat and mass transfer, the process behaviour of RSP tends to be quite complex. This paper gives an overview of up-to-date reactive separation modelling and design approaches and covers both steady-state and dynamic issues. These approaches have been applied to several different RA and RD processes including the absorption of NOx, coke gas purification, methyl acetate synthesis and methyl tertiary butyl ether (MTBE) synthesis.