Study On Process Intensification Of Ethyl Acetate Production By Hollow Fiber Composite Membranes With Catalysis And Pervaporation Capabilities

Pervaporation gets more and more extensive attention owing to its integration with other processes, such as reaction, rectification and reactive distillation, with the main advantages of compact structure, reduction of investment and operating expenses. In this paper, pervaporation hollow fiber composite membranes with catalysis have been prepared, PAN as support, PVA surface crosslinked with GA as pervaporation layer, PFSA embedded with nano particles as catalytic layer. They were applied to EtAc production via process intensification in esterification and reactive distillation. The conclusions were as follows:Firstly, pervaporation hollow fiber composite membranes (PMs) and catalytic hollow fiber composite membranes (CMs) were prepared by dip-coating method. Both membranes showed excellent hydrophilicity, mechanical properties and pervaporation performances. Secondly, PMs and CMs were applied to PV-esterification coupling process as a membrane module, respectively. By-product water was permeselected through hydrophilic membranes, thus equilibrium was overcome to improve the esterification yield of acetic acid with ethanol. Process of PMs with catalyst PFSA distributing in reaction solution displayed a better intensification performance than that of CMs. PMs were choosen to investigate the effect of operating conditions on PV-esterification coupling process. And then, CMs were used as distillation packing for EtOH-H2O separation. When gas and liquid phases flowed in shell side of membranes, vacuum tube side maked PV and distillation coupled. Different from conventional distillation, the total reflux coupled system didn’t keep steady state, and could get EtOH product beyond the azeotropic composition. When the identical idea came to reactive distillation for EtAc production, the overhead product was just H2O-EtOH-EtAc ternary mixtures. Concentration of by-product H2O got reduction through PV, which consequently promoted reaction with catalytic membrane as packing. At110℃, reactant ratio of1:2, CMs amount of15, reflux ratio of3.0, conversion of the PV-RD process was higher (87.0%), while overhead EtOH content was also higher. By comparing before and after use condition of CMs, it was found that CMs could be used in PV-RD coupling process at least18h, keeping their intensification performance.