Comparison of spiral wound and hollow Fiber microfiltration membranes for milk protein fractionation

Polymeric spiral wound membranes have been commonly used for skim milk fractionation to separate casein and serum proteins. In the recent years the use of hollow fiber membranes has gained interest. This is due to the configurational advantages that they possess such as open flow channels that aid in controlling fouling. The efficiency of hollow fiber and spiral wound membranes during skim milk fractionation at 10 °C was investigated, while operating in batch diafiltration mode using reverse osmosis water. It was observed that permeate flux of hollow fiber membranes was significantly higher than that of the spiral wound membrane. For preconcentration purposes only, both membrane configurations demonstrated similar filtration behavior as filtration is mainly controlled by the accumulated fouling layer of casein micelles on the membrane surface, and not the membrane itself. However, hollow fiber membranes were observed to have higher serum protein concentration in the permeate. During diafiltration, spiral wound membranes retained higher concentration of serum protein as compared to the hollow fiber membranes, resulting in a lower serum protein permeate yield. Hollow fiber membranes achieve higher serum protein purity compared to spiral wound membranes when the serum protein yield of both membranes is kept constant. For combined preconcentration and diafiltration purposes, hollow fiber membranes perform better.