Removal of methyl tert-butyl ether from water by pervaporation: bench- and pilot-scale evaluations

The ability of pervaporation to remove methyl tert-butyl ether (MTBE) from water was evaluated at bench and pilot scales. Process parameters studied included flow rate, temperature, MTBE concentration, membrane module type, and permeate pressure. Pervaporation performance was assessed based on the calculated mass transport coefficient of MTBE, the single-pass removal of MTBE (only at the pilot scale), and the fluxes of water and MTBE. The observations for MTBE are compared to results for toluene and 1,1,1-trichloroethane, compounds for which removal by pervaporation has been demonstrated. MTBE removal and mass transfer coefficients were lower than for toluene and trichloroethane. However, MTBE removal efficiency improved significantly with increasing process temperatures from 40 to 80 degrees C. With one of the pilot-scale systems, MTBE removal efficiency approached that of the other VOCs. The observed response of pervaporation performance to temperature was attributed to the strong effect of temperature on the Henry's law constant of MTBE.