Pushing membrane stability

Authors: Henk M.van Veen, Marielle D.A.Rietkerk, Donough P.Shanahan, Marc M.A.van Tuela, Robert Kreiter, Hessel L.Castricum, Johan E.ten Elshof, Jaap F.Vente

Abstract

To overcome the limitations of currently available commercial polymer and zeolite membranes for pervaporation applications, a hybrid silica membrane (HybSi®) has been developed. In this paper the unprecedented stability of HybSi® membrane technology for the dehydration of organic solvents is reported. It is shown that the HybSi® membranes are suitable for demanding separations using pervaporation at temperatures up to at least 190 °C, in aggressive aprotic solvents including N-methyl-2-pyrrolidone (NMP), and down to a pH value of ∼2. The high hydrothermal and chemical stability was proven in continuous measurements that lasted for periods of months to several years. The longest test, on the dehydration of n-butanol at 150 °C, lasted for 1000 days. The high stability parallels high fluxes and selectivities that meet current industrial demands and expectations. After a period of stabilization, fluxes and selectivities become constant. The presented results show that HybSi® membranes are widely applicable in the dehydration of organic solvents by pervaporation.

Graphical abstract