A hybrid reactive distillation process with high selectivity pervaporation for butyl acetate production via transesterification

A hybrid reactive distillation system with high selectivity pervaporation was examined to produce butyl acetate and methanol via transesterification of methyl acetate with butanol. High selectivity pervaporation was combined with reactive distillation to eliminate a hitherto required column for the separation of a methanol and methyl acetate azeotrope. The polyamide-6 membrane was used for this purpose because of its high selectivity for methanol while also allowing sufficient permeate flux. The high purity methyl acetate recovered in the retentate stream leads to high conversion in the reactive distillation column, which enhances the energy savings (up to 71%) of this process. The feasibility of the proposed hybrid processes and several alternative designs were evaluated by rigorous simulation and optimization using the Aspen Plus software package. The effects of several designs and operating variables were also investigated for the proposed design. The high potential of the hybrid reactive distillation and pervaporation system for butyl acetate production is very promising; it may not only reduce the total annual costs relative to conventional systems but may also provide an attractive strategy to address problems associated with methanol and methyl acetate azeotropes in the effluent generated in the polyvinyl alcohol industry

C3 Paper

Ultrafiltration (UF) has been proposed as a promising technology in recirculating aquaculture systems (RAS) to remove both organic contaminants and other fine contaminants including viruses and pathogenic bacteria. However, fouling is still a severe problem during this application. This paper investigated the fouling behavior of three different UF membranes examined using five different aquaculture contaminants. The experiments were performed using UF membranes with molecular weight cut-off 10, 50, and 100 kDa. Humic acid, shrimp feed, Spirulina sp., Vibrio harveyi and IHHNV were used as contaminant models. Scanning electron microscope was used to visualize the presence of foulant on the membrane surface. The results showed that fouling behavior was affected by both membrane cut-off (pore size) and foulant type. Two fouling behaviors were observed: (i) rapid flux decline at the early stage of filtration followed by relatively constant permeate flux until experiments finished, and (ii) rapid flux decline at the early stage of filtration followed by a gradual decrease in permeate flux. Due to its reliable flux value and high rejection, 100 kDa UF membrane should be considered as the most suitable UF membrane for RAS application