(780e) Industrial Membrane Hybrid Driers

This paper describes a chemically and thermally resistant membrane system for the dehydration of organic solvents and chemicals. The hydrated chemical can be fed to the system either in the liquid or the vapor phase. The feed to the membrane is separated into an organic rich fraction in the retentate and a water rich fraction in the permeate. The solvent recovery depends on the permeability of the membrane to the solvent and the purity required in the solvent-rich fraction. Applications of this technology include (but are not limited to) drying organics that are difficult to dry by conventional technologies (e.g., azeotropes or solvents that have boiling points close to water), heat sensitive chemicals,   reacting mixtures in which the chemical reaction is inhibited by the presence and/or generation of  water. This technology is been used commercially for the successful dehydration of lubricating oils. Pilot scale test data are presented on the application of this technology for drying ethanol, IPA, THF, toluene and phosphate esters.  The membrane system can be combined with conventional distillation to create a hybrid process for removing water from organics resulting in cost and energy savings. Examples of this hybrid drying process are presented along with the economic advantages derived from using the hybrid technology.