This raw-material liquid concentration system is for use in a pharmaceutical product manufacturing process, and employs a membrane-distillation method involving: bringing a raw-material liquid containing a solvent and a solute into contact with cooling water through a membrane-distillation membrane; passing the solvent in the raw-material liquid through the membrane-distillation membrane in the form of vapor; and causing the solvent to move toward the side of the cooling water, wherein the membrane-distillation membrane is a porous membrane that has a water contact angle of at least 90? at the surface thereof, has an average pore diameter of 0.02-0.5 ?m, and has a porosity of 60-90%.

A membrane separation system is provided comprising at least two membranes in series. A first membrane in the series is oleophobic and comprises: (a) a porous substrate; and (b) an oleophobic coating layer applied to at least one surface of the substrate. A second membrane in the series is hydrophilic. The second membrane may comprise a hydrophilic porous substrate, and/or the second membrane further comprises a hydrophilic coating layer applied to at least one surface of the second membrane substrate. Also provided are methods of separating aqueous emulsions, comprising: (i) contacting an aqueous emulsion with the membrane separation system described above; and (ii) allowing water in the emulsion to permeate through the membrane separation system to yield an aqueous product stream.

A system for upgrading biogas through a membrane separation process comprises an anaerobic digester, operated under an operation pressure higher than atmosphere pressure, preferably greater than 4 baba, generating the biogas, a first membrane stage and a second membrane stage, separating the biogas into a residue stream, enriched in CH.sub.4, and a permeate stream, enriched in CO.sub.2, a compressor compressing the permeate stream to a pressure slightly greater than the operation pressure, and recycling the permeate stream back to the bottom volume of the anaerobic digester.

The present disclosure relates to a scaling-resistant and yellowing-resistant composite reverse osmosis membrane and a preparation method thereof. By modifying the stability and yellowing of a coating of the reverse osmosis membrane, and grafting 2-(methacryloyloxy)ethyl)dimethyl-3-sulphoproyl) ammonium hydroxide (MEDSAH) and ethylene glycol methacrylate (EGMA) as amphoteric monomers and N-(isobutoxymethyl)acrylamide (IBMA) as yellowing-resistant particles on a surface of the reverse osmosis membrane using active polymerization, the present disclosure forms a three-network high-performance PMEDSAH/PEGMA/PIBMA composite coating. By active regulation of a polyamide (PA) layer through the three systems, the reverse osmosis membrane has high compatibility due to PMEDSAH, and stability, high hydrophilicity and anti-protein fouling property due to PEGMA, as well as yellowing-resistant property by coating PIBMA on the surface. The test results show that the reverse osmosis membrane prepared by the present disclosure has excellent stability and yellowing-resistant property. And the flux and salt rejection are also higher than those of the existing reverse osmosis membranes.

A polyimide separation membrane is comprised of a polyimide, a halogen compound (e.g., halogenated aromatic epoxide) that is soluble in the polyimide and a hydrocarbon having 2 to 5 carbons (e.g., ethane, ethylene, propane or propylene). The gas separation membrane has improved selectivity for small gas molecules such as hydrogen compared to polyimide membrane not containing the halogen compound or hydrocarbon. The polyimide separation membrane may be made by shaping a dope solution comprised of a polyimide, a halogen containing compound that is soluble in the polyimide, removing the solvent and then exposing the untreated polyimide membrane to a treating atmosphere comprising a hydrocarbon having 2 to 5 carbons for a sufficient time to form the polyimide membrane.

A porous asymmetric membrane comprises a hydrophobic polymer comprising a poly(phenylene ether) or poly(phenylene ether) copolymer; and a polymer additive. A separation module can be fabricated from the porous asymmetric membrane. A method of forming the porous asymmetric membrane comprises: dissolving a hydrophobic polymer comprising a poly(phenylene ether) or poly(phenylene ether) copolymer and, a polymer additive in a water-miscible polar aprotic solvent to form a porous asymmetric membrane-forming composition; and phase-inverting the porous asymmetric membrane forming-composition in a first non-solvent composition to form the porous asymmetric membrane. The polymer additive comprises hydrophilic functional groups, copolymerized hydrophilic monomers, or blocks of hydrophilic monomer repeat units. For example, the polymer additive can comprise a hydrophilic polymer or amphiphilic polymer. The porous asymmetric membrane can be a flat membrane or hollow fiber.

A porous asymmetric membrane comprises a hydrophobic polymer comprising a poly(phenylene ether) or poly(phenylene ether) copolymer; and a polymer additive. A separation module can be fabricated from the porous asymmetric membrane. A method of forming the porous asymmetric membrane comprises: dissolving a hydrophobic polymer comprising a poly(phenylene ether) or poly(phenylene ether) copolymer and, a polymer additive in a water-miscible polar aprotic solvent to form a porous asymmetric membrane-forming composition; and phase-inverting the porous asymmetric membrane forming-composition in a first non-solvent composition to form the porous asymmetric membrane. The polymer additive comprises hydrophilic functional groups, copolymerized hydrophilic monomers, or blocks of hydrophilic monomer repeat units. For example, the polymer additive can comprise a hydrophilic polymer or amphiphilic polymer. The porous asymmetric membrane can be a flat membrane or hollow fiber.

A porous composite membrane includes a porous support layer of a poly(phenylene ether) or poly(phenylene ether) copolymer; and an amphiphilic copolymer having a hydrophobic block and a hydrophilic block or graft, wherein the hydrophobic block includes a polystyrene block, a poly(phenylene ether) block, or a poly(phenylene ether) copolymer block; and an ultrathin, cross-linked, water permeable layer, which is the reaction product of an electrophilic monomer and a nucleophilic monomer, in contact with a side of the porous support layer. The reaction product can be a polyamide that is the interfacial condensation product of: an aromatic, polyfunctional acyl halide comprising of 3 to 6 acyl halide groups per aromatic ring and an aromatic polyamine comprising at least two primary amine groups and a maximum number of primary amine groups that is less than or equal to the number of acyl halide groups on the polyfunctional acyl halide.

The present invention provides a carbon membrane for fluid separation with which a high-pressure fluid can be separated and purified and which has excellent pressure resistance and is less apt to be damaged. The present invention relates to a carbon membrane for fluid separation, including: a core layer which has a co-continuous porous structure; and a skin layer which has substantially no co-continuous porous structure and is formed around the core layer.

The present invention relates to a composite semipermeable membrane including: a substrate; a porous support layer disposed on the substrate; and a separation functional layer disposed on the porous support layer, in which the separation functional layer includes: a first layer including a crosslinked aromatic polyamide; and a coating layer existing on the first layer and including an aliphatic polyamide including a fluorine atom, and the composite semipermeable membrane has a proportion of the number of fluorine atoms to the total number of atoms of all elements of 0.5% or more and 8% or less, and has a ratio (N/O ratio) of the number of nitrogen atoms to the number of oxygen atoms of 0.8 or more and 1.3 or less.