Preparation and characterization of nanofiltration (NF) polyethersulfone and its preliminary studies on beta-carotene concentration from crude palm oil

The enrichment of beta-carotene concentration from crude palm oil (CPO) using nanofiltration polyethersulfone (NF-PES) membrane was studied. This work begins with preparing the NF-PES membrane via the phase inversion method as the first stage. PES polymer was used as base membrane material and N-Methyl-2-Pyrrolidone (NMP) as a solvent. Then, the process concentration of beta-carotene was conducted by filtration of the red palm methyl ester as feed solution using dead-end mode filtration. The objective of this work was to evaluate the effect of separation pressure (3; 4; and 5 bar) on beta-carotene concentration from the feed solution. SEM results showed that the NF PES membrane had an asymmetric structure. It consisted of two layers: the thin top layer had a dense structure, while the support layer had a sponge-like structure. Besides, the pure water permeability of NF PES membrane was about 2-18 L/m2.h.bar was fitted within the range of NF membranes. The optimum operating pressure that gives the highest beta-carotene concentration was achieved at 3 bar. As a result, the beta-carotene concentration has improved about 1.14 times compared to the initial beta-carotene concentration in the feed solution.