Two-phase flow microfiltration successfully reduced the fouling problem for several microfiltration processes. Two-phase flow, created by introducing air into the fluid, increased the permeate flux 120%, 45%, and 40% for three different fermented biomass solutions at one hour operating time. For cheese whey microfiltration, the two-phase flow method successfully improved the permeate flux approximately 50% with only 5% air. Without the two-phase flow method, the permeate flux increased 20% when the liquid flow rate was doubled. Intermittent use of air was less effective than continual addition. Operating parameters of two-phase flow microfiltration, such as liquid flow rate and air percentage, were optimized based on permeate flux and energy requirements. The two-phase flow technique saved more energy and processing time than simply increasing the liquid flow rate. An economic analysis was performed to estimate the annual costs for scale-up of a cheese whey microfiltration process
