Effect of Membrane Support Thickness on Supported Liquid Membrane Extraction of Levulinic Acid

One of the most appealing compounds in biomass products is levulinic acid (LA). At the same time, separating LA from biomass products is a significant issue in LA production. Supported liquid membrane (SLM) is a revolutionary technique for separating LA from biomass. This study studied the effect of different casting thicknesses of hybrid polyethersulfone graphene membrane from 300 µm to 450 µm on the membrane characteristic and extraction yield of LA via the SLM process. The liquid membrane impregnated into the membrane support was made of 0.3 M trioctylamine and 2-ethyl-1-hexanol. The morphology, surface contact angles, porosity, tensile strength, and performance of the support membrane were evaluated. The membrane cast at 400 µm extracted the most LA (86%) from the 10 g/L LA feed phase. It had an average porosity of 57.77%, surface contact angle at the top layer of 81.21°, surface contact angle at the bottom layer of 98.02°, and tensile strength of 8.41 N. The membrane casting thickness impacts the character of the membrane support and the overall performance of SLM. A suitable membrane structure is required to overcome the instability of the liquid membrane and increase the lifetime operation of SLM.