A solution containing 95 wt% protein with a viscosity of 0.0023 Pa s-1 is to undergo ultrafiltration using a pressure difference of 7 psi. The membrane was examined microscopically and found to have about 98,500 pores with an average diameter of 0.55 m, per mm square of membrane surface. It is desired to and a thickness of 120 m.

A) Assuming no effects of polarization, predict the flux in kg/s.m2.

B) What is the maximal permissible flux if a protein concentration above 4 % is to be avoided at the membrane surface? It is assumed that the convective mass transfer coefficient at the membrane-fluid interface, under the conditions of operation, is 6 X10-6 m*s-1.