Pervaporation of methanol-ethylene glycol with cellophane membrane: some mechanistic aspects

Abstract

The relationship between two-phase and three-phase solutions to heterogeneous distillation simulation and optimization problems is studied. Simulation results illustrate that bifurcation points can occur in the two-phase solutions and that, in regions of steady-state two-phase solution multiplicity, not

Preparation and application of dense poly(phenylene oxide) membranes in pervaporation

“…It is worth mentioning that, compared to cellophane membrane used for methanol/ethylene glycol separation, higher methanol selectivity with almost similar fluxes are achieved by the PPO membranes prepared for this study [6], while in comparison to the copolymerized acrylonitrile membranes with hydroxyethyl methacrylate, methacrylic acid or vinyl pyrrolidone, both flux and methanol selectivity obtained by PPO membranes are higher [7].…”

“…In fact, the diffusion cross section of methanol, 14.4 Å 2 , is lower than that of ethylene glycol, 23.4 Å 2 [7]. For pervaporation of methanol-ethylene glycol mixture, Ghosh et al [6] and Ray et al [7] obtained similar trends when using cellophane and copolymerized acrylonitrile membranes, respectively.…”

“…Recently various studies were carried out on the separation of methanol from aromatic hydrocarbons, alkanes, ethers, esters, etc. [3][4][5][6][7][8]. However, despite its importance, pervaporative separation of methanol is not as advanced as pervaporative dehydration.…”

“…In fact, the separation of methanol from ethylene glycol is industrially important in the manufacture of poly(ethylene terephthalate) in the polyester industry. Ghosh et al [6] proposed the use of a cellophane membrane of thickness 25 µm for the pervaporation separation of the methanol-ethylene glycol mixture. It was found that methanol permeated preferentially through the membrane, with a separation factor less than 59 and permeate fluxes lower than 0.4 kg/m 2 h at a feed temperature of 30 • C. Later on, Ray et al [7] used acrylonitrile copolymerized membranes of thickness 50 µm and found that the copolymers hydroxyethyl methacrylate and methacrylic acid showed selectivities of 14.7 and 11.3 with fluxes of 0.108 and 0.0813 kg/m 2 h, respectively, whereas the copolymer vinyl pyrrolidone showed comparable flux but poor methanol selectivity.…”

Separation of azeotropic organic liquid mixtures by pervaporation

“…Later, Mulder et al (1982) applied pervaporation to the separation of isomeric xylenes by thin films of cellulose esters. Recently, Ghosh et al (1988) reported separating mixtures of methanol and ethylene glycol by cellophane membranes.…”