Experimental study on the enhancement of yeast microfiltration with gas sparging
Sur HW., Cui Z.
Gas-sparged microfiltration experiments with baker's yeast suspensions were performed using a 0.15 μm PCI multi-tubular membrane module. The permeate flux and the enhancement from gas sparging were measured over the following operational parameter ranges: yeast suspension concentration 0.01-10% (wt), transmembrane pressure 0.5-4.0 bar, liquid crossflow velocity 0.36-1.8ms-1, gas superficial velocity 0.18-1.02ms-1. It was demonstrated that injecting air to create a gas-liquid two-phase crossflow operation can significantly increase the permeate flux. The observed enhancement, resulting from injecting a relatively small amount of gas with a superficial velocity of 0.18ms-1, ranges from 10% when fouling is insignificant to 135% when fouling tendency is severe. Controlled pulse injection leads to further increase in permeate flux. Examining the dependence of permeate flux on transmembrane pressure, it is clearly demonstrated that the injection of gas will elevate the value of the limiting flux. There is also evidence to show that the value of critical flux is increased when gas injection is applied. Further quantitative analysis will be performed in our future work. © 2001 Society of Chemical Industry.