Pervaporation Of Methanol Research Articles

Pervaporation Purification of Ethylene Glycol Using the Highly Permeable PIM-1 Membrane

Ethylene glycol (EG) is an essential chemical and forms mixtures with water or methanol in the production processes. Its purification is imperative in the production of pure EG from its water/methanol mixtures. Conventionally, distillation is employed in this separation process at the expense of massive energy consumption. Here water/methanol–EG mixtures are separated by the highly permeable PIM-1 membrane via pervaporation to produce the pure EG product. PIM-1 is one of most representative polymers of intrinsic microporosity (PIMs) that are attractive membrane materials. The overall separation performances for water/methanol–EG mixtures are investigated systematically. The membrane shows good separation performances as well as high purifying efficiency. Typically, the membrane has a high flux of 10.40 kg μm m–2 h–1 and separation factor of 24.2 in the pervaporation of methanol (18.50 wt %)–EG mixtures at 30 °C. In addition, effects of feed composition and temperature are investigated respectively on the ...

Mixed matrix membranes with hybrid star-shaped macromolecules for mono- and dihydric alcohols pervaporation

Mixed matrix membranes were obtained by including hybrid star-shaped macromolecules (HSM) in a matrix of polyphenylene oxide (PPO). HSM filler was a twelve-arms star with six polystyrene arms and six diblock copolymer poly(2-vinylpyridine)-b-poly(tert-butylmethacrylate) arms grafted onto a fullerene C60 center. The PPO/HSM membranes structure was studied by scanning electron microscopy and the energy dispersive spectrometry. Mass transfer through PPO/HSM membranes was studied by sorption and pervaporation tests toward methanol and ethylene glycol. In the pervaporation of methanol – ethylene glycol mixture over the concentration range of 5–30wt.% methanol in feed, all membranes showed high affinity to methanol and produced permeate concentrated in methanol. The total flux through the membrane increased with the growth of both the HSM content in membrane and the methanol concentration in the feed. Separation factor achieved maximal magnitude at the filler concentration in membrane equal to 5wt.% HSP. To evaluate intrinsic properties of the penetrant – membrane system, permeability and selectivity were calculated. The dependence of methanol permeability on methanol concentration in the feed was opposite to that of the flux. It was shown that PPO/HSM membranes exhibit the best properties when the feed enriched with ethylene glycol.

Pervaporation of methanol from methylacetate mixture using polyamide-6 membrane

This article presents the results concerning the preparation of asymmetric polyamide-6 (PA-6) membrane using the wet phase inversion technique. The membrane was prepared from a casting dope containing 20 wt.% of PA-6 in formic acid at 18°C. The membrane was then characterized by scanning electron microscopy and further tested for the separation of methanol/methyl acetate solutions by pervaporation. The effects of feed methanol concentration, operating temperature and the feed liquid flow rate on the membrane performance were investigated. The permeation flux increased with increasing feed methanol concentration, feed temperature, and feed flow rate. Some typical data of separation factor were: at the operating temperature of 40°C, feed 80% methanol/20% methyl acetate and the feed liquid flow rate of 16.5, 20.6 mL/s, the separation factor was 50 and 83 respectively.

Mixed Matrix Membranes Based on Polyamide/Montmorillonite for Pervaporation of Methanol–Toluene Mixture

Novel mixed matrix membranes were obtained by the dispersion of montmorillonite (MMT) nanoparticles in poly(phenylene-iso-phtalamide) (PA) matrix. Membrane structure was determined on the basis of density measurement and morphology study by SEM. The effect of MMT inclusion on membrane hydrophilic properties was estimated by the measurement of contact angles of water, methanol, and toluene, respectively, and the calculation of surface tension. Transport properties of PA/MMT membranes were studied by use of swelling and pervaporation tests. The prepared membranes were used in the pervaporation of methanol–toluene mixtures. Total fluxes and separation factors, such as permeabilities and selectivities, were determined. It was established that the improvement of some physicochemical properties and transport parameters occurs only by inclusion up to 3 wt% MMT in the PA matrix.

Pervaporation separation of MeOH/MTBE mixtures with modified PEEK membrane: Effect of operating conditions

Modified poly(ether ether ketone) (PEEKWC) dense membranes were prepared using chloroform as the evaporating solvent. Pervaporation of methanol (MeOH) and methyl tert-butyl ether (MTBE) mixtures were carried out at different feed concentrations, flow rates and temperatures. The swelling and mechanical properties of the membranes were studied at different MeOH concentrations. These MeOH selective membranes were mechanically strong for PV tests. However, their strength decreased in feed mixture to some extent particularly in contact with high concentrations of MeOH. The observed high separation factor of more than 250 at 1wt% MeOH dropped to an ultimate value of 4–6 at around 20–50wt% MeOH. Meanwhile, total permeation flux increased tenfold continuously from 0.015kg/m2h to 0.113kg/m2h at 87.2wt% MeOH in feed. Increasing the feed flow rate had a positive effect on both the separation factor and the permeation flux due to the elimination of concentration and temperature polarization. Increasing the feed temperature improved the permeation rate as well. However, the separation factors slightly decreased at higher temperatures. The observed effects of feed temperature on the PV results are caused by increasing the thermal motions of polymer chains and permeating molecules at higher temperatures.

Polyamide Membranes Modified by Carbon Nanotubes: Application for Pervaporation

New polymer nanocomposites consist of poly(phenylene isophtalamide) (PA) modified by carbon nanotubes (CNT) were obtained by the solid state interaction method to prepare dense membranes. The investigation of the PA/CNT nanocomposites was made by Raman spectroscopy. The morphology of the dense membrane was analyzed by SEM. The transport properties of the dense polyamide membranes modified by 2 and 5 wt% CNT were studied in pervaporation of methanol/ methyl tert-butyl ether mixture. It was shown that the selectivity with respect to methanol and permeability were the highest for membranes containing 2 wt% CNT as compared to membranes of pure PA and containing 5 wt% CNT. To analyze transport properties the sorption tests and contact angle measurements were employed.

Pervaporation of methanol–water mixture by poly(γ‐methyl L‐glutamate) membrane and synergetic effect of their mixture on diffusion rate

AbstractThe pervaporation behaviors of methanol–water by poly(γ‐methyl L‐glutamate) (PMLG) membrane at non‐steady‐ and steady‐state permeation were investigated. The values of t1/2 (time required to reach a half value of steady‐state permeation flux) for methanol and water changed and did not change with the component in feed, respectively. Both of the average diffusion coefficients for methanol–and water–PMLG from the mixture changed exponentially with the sorption amount of methanol by the synergetic effect on diffusion. The difference in behavior of non‐steady and steady state diffusion was explained by whether Do (diffusion coefficient at zero penetrant concentration) was influenced by the concentration distribution of penetrant in PMLG membrane.