Pervaporation process using a thermal gradient as the driving force

Abstract

SummaryA new process design for pervaporatlon 1s described m which a composite membrane, conslstmg of a selective hydrophlhc toplayer and a mlcroporous hydrophobic sublayer, IS used [ 1 ] The feed mixture IS brought into contact wth the hydrophlhc layer At the permeate side of the membrane a permeate-absorbing liquid 1s brought into contact with the porous sublayer The driving force for this process IS caused by the thermal gradient that exists between the warm feed side of the membrane and the cold permeate side The restnctmg condltlon of this process design 1s that the liquid at the downstream side does not penetrate mto the pores of the hydrophobic membraneIn this design, the equipment generally needed m conventional pervaporatlon processes to produce a reduced pa&al pressure at the permeate side and to condense the permeatmg vapour 1s no longer necessaryThe performance of the membranes IS comparable to those m a conventional pervaporatlon process

Recent advances on membrane processes for the concentration of fruit juices: a review

“…The shearing forces generated at high flow rate cause a lower accumulation of particulates such as pectin and cellulose on the active membrane surface and thus reduce membrane fouling. Besides, a lower crossflow velocity causes a lower Reynolds number, thus hindering the heat transfer from the bulk of the solution to and from the membrane surface, and an effect of temperature polarization are more severe than that of high crossflow velocity (Franken, Mulder, & Smolders, 1990).…”

Liquid Separation by Membrane Pervaporation: A Review

“…Vacuum pervaporation, which is customarily referred to as the standard pervaporation, is the most widely utilized mode of operation, while inert purge pervaporation is normally of interest if the permeate can be discharged without condensation. Besides these two modes of operation, there are several other process variants, including thermal pervaporation, perstraction or osmotic distillation, saturated vapor permeation, and pressure-driven pervaporation (Franken et al, 1990;Neel, 1991;Goncalves et al, 1990). Some of them are really process hybrids rather than process variants.…”

Pervaporative desulfurization of gasoline: A review

“…Presently, there are two commercial applications of pervaporation-one is the dehydration of alcohols and other solvents while the second application is the removal of trace volatile organic substances from water [41]. The pervaporative separation is a membrane processing of mixtures of liquid, by partial vaporization through a dense and nonporous membrane for selective permeation of one or more components from a liquid mixture [42]. As a result, the more permeable species in the permeate and the less permeable species in the feed can be concentrated.…”

“…Saudi Aramco: Company General Use 9 In this context, the S-Brane of Grace Davison Company and TranSep TM of TransIonics Corporation represents the successful membrane-dominated techniques for removal of sulfur from gasoline stream in which all costs only account for 20% of the conventional HDS process [42][43][44][45]. It is worth noting that the pervaporative desulfurization can be used alone or coupled with another desulfurization process.…”