Pervaporation separation of ethanol and 2-ethylhexanol mixtures using cellulose acetate propionate and poly(1-vinylpyrrolidone-co-vinyl acetate) blend membranes

Pervaporation recovery of ethanol from 2-ethylhexanol was investigated using cellulose acetate propionate (CAP) and poly(1-vinylpyrrolidone-co-vinyl acetate) (PVP/PVAc) blend membranes. The effects of feed composition, membrane composition, and operating temperature on membrane sorption and separation performance were studied experimentally. Fluxes and permeances of individual components, as well as separation factors and selectivity of ethanol to 2-ethylhexanol were determined for temperatures of 40-60 ?C, feed composition of 5-25% ethanol, and 10-30% copolymer mass fraction in the membrane. Ethanol fluxes of up to 683 g m(-2)h(-1) and permeances of up to 278 g m(-2)h(-1) kPa(-1) were observed at 50 degrees C. Results showed that higher feed composition and temperatures produce higher ethanol fluxes. However, increasing the ethanol feed concentration has an inversely proportional effect on selectivity and separation factor. Analysis of ethanol permeance results indicate that feed and operating conditions can strongly influence separation performance and measuring parameters that consider and isolate those effects should be preferred.

Automated summary

Experimental results showed that higher feed composition and temperatures lead to higher ethanol fluxes, but increasing ethanol feed concentration has an inversely proportional effect on selectivity and separation factor.