Review of Pervaporation and Vapor Permeation Process Factors Affecting the Removal of Water from Industrial Solvents

A recent review article (Journal of Chemical Technology & Biotechnology 94: 343–365 (2019)) identified several commercially‐available permselective materials for drying organic solvents with pervaporation (PV) and vapor permeation (V·P) separation processes. The membrane materials included polymeric and inorganic substances exhibiting a range in the performance characteristics: water permeance, water/solvent selectivity, and maximum use temperature. This article provides an overview of the factors affecting the design of PV/V·P processes utilizing these membranes to remove water from common organic solvents. Properties of the specific membrane and of the solvent substantially affect the PV/V·P separation. Equally important is the impact of operating parameters on the overall separation. To study these impacts, simplified process performance equations and detailed spreadsheet calculations were developed for single‐pass and recirculating batch PV systems and for single‐pass V·P systems. Estimates of membrane area, permeate concentration, solvent recovery, permeate condenser temperatures, and heating requirements were calculated. Process variables included: solvent type, water permeance, water/solvent selectivity, initial and final water concentrations, operating temperature (PV) or feed pressure (V·P), temperature drop due to evaporation (PV) or feed‐side pressure drop (V·P), and permeate pressure. The target solvents considered were: acetonitrile, 1‐butanol, N,N‐dimethyl formamide, ethanol, methanol, methyl isobutyl ketone, methyl tert‐butyl ether, tetrahydrofuran, acetone, and 2‐propanol. Published 2019. This article is a U.S. Government work and is in the public domain in the USA.