Surface morphology of pvdf membrane and its fouling phenomenon by crude oil emulsion

In this study, polyvinylidene fluoride (PVDF) flat sheet membranes were fabricated via phase inversion process for crude oil emulsion separation. The PVDF solutions were formulated by varying polymer concentration from 16 to 19 wt.% with one of the three different solvents: N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), and N-methyl-2-pyrrolidone (NMP). The membranes morphologies as a result of different polymer concentration and solvents were characterized and their effects on the crude oil emulsion separation were evaluated. Results showed that 18 wt.% PVDF-DMAc membrane was the optimum membrane for oil emulsion in term of flux recovery ratio (FRR) which showed better cleaning ability compared to other membranes. Under cake deposition fouling mode (with proven oil particle size bigger than the pore size), membrane fouling tendency is regardless of porosity or pore size. However, both of these properties do play important roles in the subsequent fouling cleaning process. Membrane with least porosity and smaller pore size has better cleaning properties.