Abstract:
A vapor permeation method and apparatus for removing a vapor from a vaporous feed stream, the method and apparatus utilizing highly solvent-resistant composite hollow fiber membranes and a permeate flow countercurrent to the feed flow, wherein the support of the composite membrane is formed by solution casting and has been rendered sufficiently solvent-resistant by a post-casting step to retain at least 20 of its burst pressure when soaked in the solvent used to cast the support.
Abstract:
A process for the dehydration of a vaporous mixture. The basic process involves directing a predominantly condensable water vapor-containing vaporous mixture against the feed side of a membrane while maintaining the feed near saturation without condensing it, directing a condensable vapor sweep stream past the permeate side of the membrane in a countercurrent flow, thereby transporting water vapor in the vaporous mixture from the feed side to the permeate side of the membrane to form a noncondensed combined permeate side mixture of condensable vapor and transported water vapor.
Abstract:
A process for the removal of at least one non-water vapor component of a vaporous mixture, the basic process comprising directing a vaporous mixture against the feed side of a membrane, directing a condensable vapor sweep stream past the permeate side of the membrane in a manner such that the flow of the condensable vapor sweep is substantially countercurrent to the flow of the vaporous mixture, thereby transporting at least a portion of at least one non-water vapor component of the vaporous mixture from the feed side to the permeate side of the membrane to form a combined permeate side mixture of condensable vapor and at least one non-water vapor transported component.
Abstract:
A process for removing and recovering a condensable vapor from a gas stream by a membrane contactor is disclosed wherein a gas stream containing a condensable vapor is circulated on one side of hollow fiber membranes while cool extraction fluid is circulated on the other side under a total pressure differential, thereby condensing the condensable vapor in the gas stream, the condensed vapor permeating the membrane and becoming entrained in the cool extraction fluid.
Abstract:
Hybrid membrane-based separation systems are disclosed that are useful in separating solvents and solutes. The hybrid systems combine any of the solvent removal processes reverse osmosis, nanofiltration, membrane distillation and pervaporation with any one of more of the solute removal processes utilizing pervaporation membranes, supported-liquid membranes, coupled transport membranes, and membrane contactors, the solvent and solute removal processes forming part of a recycle stream that utilizes membrane separation retentates as feeds and as recycle feed stream make-up.
Abstract:
Membrane-based vapor permeation system for selective removal of a vapor from a fluid feed stream, wherein a countercurrent sweep stream is used that has a particular partial pressure of the vapor to be removed.
Abstract:
A gas dehydration method and apparatus are disclosed which utilize lumen-side feed, hydrophilic polymer-inside-coated, thin-film composite hollow fiber membranes, the support fiber of which is highly permeable, such composite membranes being used in a module wherein the permeate flows countercurrent to the flow of the feed, and in which dried raffinate gas is mixed with water-containing permeate at a point opposite the feed end of the module.
Abstract:
A gas dehydration method and apparatus are disclosed which utilize lumen-side feed, thin-film which is highly permeable, such composite membranes being used in a module wherein the permeate flows countercurrent to the flow of the feed.
Abstract:
A system for the ultrapurification of organic solvents comprising (1) a membrane-based vapor permeation step for selective removal of water vapor from the solvent, wherein a countercurrent sweep stream is used that has a particular partial pressure of water vapor, (2) a filtration step for selective removal of particulates, and (3) an ion exchange step for selective removal of ionic species.