Systems and methods for separating organic chloramines and inorganic chloramines from an aqueous solution. Such a method includes providing a first container containing an aqueous solution that includes organic and inorganic chloramines and free chlorine, providing a second container containing a trapping solution and a tubular hydrophobic membrane through which inorganic chloramines contained in the aqueous solution can diffuse into the trapping solution, pumping the aqueous solution from the first container through the tubular hydrophobic membrane of the second container; and collecting the aqueous solution pumped through the tubular hydrophobic membrane in a third container connected to the tubular hydrophobic membrane. After pumping is completed, the second container contains an aqueous solution containing the inorganic chloramines and the third container contains an aqueous solution containing the organic chloramines and the free chlorine.

An inert gas generating system includes a source of a liquid hydrocarbon fuel, and a fractioning unit configured to receive a portion of the liquid hydrocarbon fuel from the source. The fractioning unit includes a perm-selective membrane configured to separate the portion of the liquid hydrocarbon fuel into substantially sulfur-free vapors and a sulfur-containing remainder. The system further includes a catalytic oxidation unit configured to receive and react the substantially sulfur-free vapors to produce an inert gas.

A method of separately producing tert-butanol and sec-butanol, comprising the steps of introducing a mixed butenes stream to a tube side of a reaction membrane unit, introducing a TBA reactor water feed to the tube side of the reaction membrane unit, introducing a sweep gas to a shell side of the reaction membrane unit, introducing an SBA reactor water feed to the shell side, allowing the mixed butenes stream to contact the tube side of a such that selective gases in the mixed butenes stream permeate through the membrane to the shell side, allowing the selective gases that permeate through the membrane to react with water to produce sec-butanol, allowing retentate gases that fail to permeate through the membrane to react with water to produce tert-butanol, collecting the tert-butanol in a TBA reactor effluent, and collecting the sec-butanol in a SBA reactor effluent.

A preparation method of separation membrane is provided. First, a polyimide composition including a dissolvable polyimide, a crosslinking agent and a solvent is provided. The dissolvable polyimide is represented by formula 1: ##STR00001## wherein B is a tetravalent organic group derived from a tetracarboxylic dianhydride containing aromatic group, A is a divalent organic group derived from a diamine containing aromatic group, A is a divalent organic group derived from a diamine containing aromatic group and carboxylic acid group, and 0.1X0.9. The crosslinking agent is an aziridine crosslinking agent, an isocyanate crosslinking agent, an epoxy crosslinking agent, a diamine crosslinking agent, or a triamine crosslinking agent. A crosslinking process is performed on the polyimide composition. The polyimide composition which has been subjected to the crosslinking process is coated on a substrate to form a polyimide membrane. A wet phase inversion process is performed on the polyimide membrane.

A composite membrane for selectively separating (e.g., pervaporating) a first fluid (e.g., first liquid such as a high octane compound) from a mixture comprising the first fluid (e.g., first liquid such as a high octane compound) and a second fluid (e.g., second liquid such as gasoline). The composite membrane includes a porous substrate comprising opposite first and second major surfaces, and a plurality of pores. A pore-filling polymer is disposed in at least some of the pores so as to form a layer having a thickness within the porous substrate. The composite membrane further includes at least one of: (a) an ionic liquid mixed with the pore-filling polymer; or (b) an amorphous fluorochemical film disposed on the composite membrane.

A microporous polymeric composition including a matrix polymer having a fractional free volume of at least 0.1 and dispersed particles having a hypercrosslinked polymer.

The invention relates to a method for producing alkyl (meth)acrylate comprising a linear or branched alkyl chain comprising 4 to 10 carbon atoms, by direct esterification of (meth)acrylic acid with a linear or branched alcohol comprising 4 to 10 carbon atoms in the presence of a catalyst, leading to formation of a reaction mixture comprising the desired ester, unreacted acid and alcohol, light by-products, and heavy by-products. The mixture undergoes purification treatment by separation means to obtain purified alkyl (meth)acrylate. The purification treatment comprises a step of membrane separation dehydration applied to at least one of the following: the stream subjected to the final distillation leading to the recovery of the purified (meth)acrylic ester, the aqueous stream originating from the settling out of the reaction mixture, or the stream resulting from the distillation of the light by-products present in the reaction mixture.

The present invention discloses high selectivity copolyimide membranes for gas, vapor, and liquid separations. Gas permeation tests on these copolyimide membranes demonstrated that they not only showed high selectivity for CO.sub.2/CH.sub.4 separation, but also showed extremely high selectivities for H.sub.2/CH.sub.4 and He/CH.sub.4 separations. These copolyimide membranes can be used for a wide range of gas, vapor, and liquid separations such as separations of CO.sub.2/CH.sub.4, He/CH.sub.4, CO.sub.2/N.sub.2, olefin/paraffin separations (e.g. propylene/propane separation), H.sub.2/CH.sub.4, He/CH.sub.4, O.sub.2/N.sub.2, iso/normal paraffins, polar molecules such as H.sub.2O, H.sub.2S, and NH.sub.3 mixtures with CH.sub.4, N.sub.2, H.sub.2. The high selectivity copolyimide membranes have UV cross-linkable sulfonyl functional groups and can be used for the preparation of UV cross-linked high selectivity copolyimide membranes with enhanced selectivities. The invention also includes blend polymer membranes comprising the high selectivity copolyimide and polyethersulfone. The blend polymer membranes comprising the high selectivity copolyimide and polyethersulfone can be further UV cross-linked under UV radiation.

The present invention relates to synthetic membranes and use of these synthetic membranes for isolation of volatile organic compounds and purification of water. The synthetic membrane includes a hydrophobic polymer layer located on a polymeric membrane support layer. The invention includes a method of isolating volatile organic compounds with the synthetic membrane by contacting a volatile organic mixture with the hydrophobic polymer layer of the synthetic membrane and removing volatile organic compounds from the polymeric membrane support layer of the synthetic membrane by a process of pervaporation. The invention also includes a method of purifying water with the synthetic membrane by contacting an ionic solution with the hydrophobic polymer layer of the synthetic membrane and removing water from the polymeric membrane support layer of the synthetic membrane by a process of reverse osmosis. The invention also relates to methods of isolating non-polar gases by gas fractionation.

Using GA as the crosslinking agent, the PVA/GA/CS-M.sup.+ pervaporation membrane having high mechanical strength can be readily obtained via blending the Ag.sup.+, Cu.sup.2+, or Fe.sup.3+-chelated CS precursor with PVA, performing excellent permeability and selectivity for the dehydration of organic solvents.