Simulation And Optimization Of Reactive Distillation Coupled With Side Reactors

Traditional reactive distillation is a process which combines reaction and distillation in one column, which has the advantage of simplifying the process, reducing operation cost, enhancing fractional conversation of main reaction and selectivity of target product et al, and it has been wildly applied in a large number of systems such as esterification, etherification, hydrolysis, condensation, et al. But its limitation is that reaction conditions must be in consonance with separation conditions. To extend the application of reactive distillation, the side reactor concept (SRC) is raised in which the type, volume and reaction conditions of side reactors can be adjusted independently. SRC overcomes the limitation of reactive distillation and maintains its benefits. There is a little research on the problem of matching between reaction capacity and separation capacity. The aim of this text is to establish a model to simulate and optimize the process of esterification by SRC and discuss the matching of reaction capacity and separation capacity.In view of the limitation to the reactive distillation process coupled with side reactors that the convergence of calculation was poor due to much more recycle streams, side reactors were considered as stages without separation capacity, the model of RadFrac in ASPEN PLUS was introduced to describe this complex model and Murphree stage efficiency was also introduced to distinguish side reactors from separation stages. When the total stage number of distillation column was fixed, the influence of number and spacing of side reactors, feeds location, reflux ratio and catalyst mass on the synthesis of methyl acetate were studied, and the matching of reaction capacity and separation capacity was discussed. The results of simulation showed the total conversion of acetic acid achieved 96.3% under the specific operation conditions, when five side reactors were used and the spacing of each reactor was four separated stages.Because reaction capacity and separation capacity were interactive in reactive distillation column coupled with side reactors, the matching problem of reaction capacity and separation capacity was researched by optimizing the separation capacity and fixing the reaction capacity. In the synthesis process of methyl acetate, the separation capacity (45 theory stages and reboiler duty was 6590 KJ/s) was fixed, and...