Desolventizing of soybean oil/azeotrope mixtures using ceramic membranes

Abstract

This work investigates the use of ceramic membranes with different molecular weight cut-offs (MWCOs: 5, 10 and 20 kDa) to desolventize azeotropic solvent mixtures (ethanol/n-hexane and isopropyl alcohol/n-hexane) from soybean oil/azeotrope micelles. Results show that a decrease in the MWCO of a membrane and an increase in the solvent mass ratio in the mixture resulted in a significant reduction in the permeate flux. The 20 kDa membrane presented the highest permeate flux, 80 and 60 kg/mh for the soybean oil/n-hexane/isopropyl alcohol and soybean oil/n-hexane/ethanol azeotropes, respectively, for an oil to solvent ratio of 1:3 (w/w). The highest oil retention was found using the n-hexane/isopropyl alcohol azeotrope, around 25% in the membrane with the lowest MWCO, that is, 5 kDa. It is shown that the azeotropic mixtures provided intermediate characteristics compared to the original pure solvent behavior.

An integrated process of catalytic hydrolysis and membrane separation for fatty acids production from lard oil

“…The flux increased from 12.32 to 24.34 kg/m 2 h when the pressure increased from 50 to 100 kPa, indicating that higher working pressure can increase the system's driving force . When the pressure rose to 200 kPa, however, the flux decreased to 20.81 kg/m 2 h, because higher pressure causes greater compaction of the material retained on membrane surface, thereby increasing the permeation resistance . Both concentration polarization and fouling are phenomena that can be minimized, yet not completely avoided.…”