EFFECT OF MEMBRANE DEGUMMING CONDITIONS ON PERMEATE FLUX AND PHOSPHOLIPIDS REJECTION

The objective of this study was to investigate the performance of PVDF membrane in degumming of undiluted crude soybean oil by using reverse osmosis/ultrafiltration module. The effects of membrane degumming conditions including temperature, membrane pressure, feed velocity, and volumetric concentration factor on permeate flux and phospholipids rejection were evaluated statistically. The effect of membrane pressure and volumetric concentration factor on the permeate flux was found to be statistically significant (P <0.05). An 86.11% rejection of phospholipids and average permeate flux of 17.04 L/m.h in total process were achieved at 40°C, 20 bar pressure, and 9L/min feed velocity. As the feed velocity increased to 18 L/min, phospholipids rejection and average permeate flux in total process were determined as 82.81% and 27.51 L/m.h, respectively. The flux behavior of PVDF membrane was also studied. Behavior of permeate flux with process time showed two separate regions namely; falling permeate flux region and constant permeate flux region. A second degree polynomial relationship was observed during falling permeate flux region; whereas a linear dependency was set for constant permeate flux region. A logarithmic equation was obtained when total process behavior was examined.