Process Development, Assessment, and Control of Reactive Dividing-Wall Column with Vapor Recompression for Producing n-Propyl Acetate

As a combination of the conventional reactive distillation (RD) and diving-wall column, reactive diving-wall column (RDWC) is the highly thermally integrated process that has the advantages of higher thermodynamic efficiency, lower capital cost, and smaller equipment size. In this study, the conceptual design of four different RD processes, i.e., the conventional RD, RDWC, heat-integrated RDWC (HIRDWC), and vapor recompression heat-pump-assisted RDWC (VRHP-RDWC), was presented for the production of n-propyl acetate via the esterification of n-propanol with acetic acid. The results indicate that compared with that of conventional RD process the total annual cost of RDWC, HIRDWC, and VRHP-RDWC intensified processes is reduced by 10.44, 19.40, and 74.54%, respectively, while their thermodynamic efficiency is 9.96, 15.52, and 25.53%, respectively, which are also significantly higher than that of conventional RD process (9.25%). Subsequently, since the VRHP-RDWC process exhibits the most favorable performance for intensifying the conventional RD process, two alternative control strategies were developed and assessed for the operation of VRHP-RDWC. Control performances demonstrate that the challenging VRHP-RDWC process can be operated smoothly under large disturbances of feed flow rate, water impurity in acetic acid feed, and n-propanol feed as well as for set-point changes in temperature controllers.