Liquid Permeability

Liquid permeability is a liquid flux normalized by driving force – applied pressure difference across the membrane. Liquid permeability can be expressed in volumetric or gravimetric units – [l/(m²·h·bar)] or [kg/(m²·h·bar)], respectively. This parameter is used to characterize the membrane productivity and passage of pure solvent or solution, in liquid separation process such as micro-, ultra-, and nanofiltration, reverse and forward osmosis, or hybrid processes like membranes for fuel cell. For commercial membranes liquid permeability is usually given by manufacturers along with value of molecular weight cutoff (MWCO); the last one is characterized the ability of the membrane to reject the solutes with certain molecular weight. Since it is already normalized by driving force of the process, liquid permeability shall be most likely constant value for specific membrane in certain range of operated pressures at constant feed composition and temperature. Due to its uniformity, this...