Improving efficiency of PVDF membranes for recovering water from humidified gas streams through membrane condenser

Membrane condenser (MC) is a novel and promising operation to recover evaporated water from highly humid gas discharged from industrial production. By means of hydrophobic membrane surface, water vapor condensed on membrane retention side, finally be collected. The aim of this paper is to enhance the recovery efficiency of poly(vinylidene fluoride) (PVDF) membrane in MC process. Significantly, coating three kinds of Hyflon ADs onto PVDF membranes effectively improved hydrophobicity of original ones. Among them, Hyflon AD40L/PVDF membrane showed the best membrane and MC performance, the LEPw and water contact angle of which reached 0.43 MPa and 126°, respectively. In terms of dehydration performance in MC, by coated with Hyflon AD40L, water recovery was increased from 7.92% to 18.85%, and condensate water flow (0.35 kg·m-2·h-1) was twice that of pristine ones (0.15 kg·m-2·h-1). These results indicate that Hyflon AD composite membrane is a promising candidate for MC process with high efficiency.