A dehydration method is a dehydration method for selectively separating water from a mixture that contains water, and the method includes a step of supplying the mixture to a supply side space of a separation membrane, and a step of making a pressure difference between the supply side space and a permeation side space of the separation membrane. The separation membrane includes a first zeolite membrane that faces the permeation side space and is constituted by a first zeolite and a second zeolite membrane that faces the supply side space and is adjacent to the first zeolite membrane. The second zeolite membrane is constituted by a second zeolite that has the same framework structure as framework of the first zeolite and has a lower Si/Al atom ratio than a Si/Al atom ratio of the first zeolite.

A separation membrane for selectively separating (e.g., pervaporating) a first fluid (e.g., a first liquid) from a mixture comprising the first fluid (e.g., first liquid) and a second fluid (e.g., second liquid), wherein the separation membrane includes a polymeric ionomer that has a highly fluorinated backbone and recurring pendant groups according to the following formula (Formula I): OR.sub.f[SO.sub.2N.sup.(Z+)SO.sub.2R].sub.m[SO.sub.2].sub.n-Q wherein: R.sub.f is a perfluorinated organic linking group; R is an organic linking group; Z.sup.+ is H.sup.+, a monovalent cation, or a multivalent cation; Q is H, F, NH.sub.2, NH.sub.2, O.sup.Y.sup.+, or C.sub.xF.sub.2x+1; Y.sup.+ is H.sup.+, a monovalent cation, or a multivalent cation; x=1 to 4; m=0 to 6; and n=0 or 1; with the proviso that at least one of morn must be non-zero.

Provided herein is a process for separating alkane isomers from a hydrocarbon mixture in an integrated refining unit, comprising: passing the hydrocarbon mixture through a normal alkane-selective membrane in a single stage to produce a normal alkane-enriched stream and a membrane reject stream; and feeding the normal alkane-enriched stream to a steam cracker to produce olefins; wherein the hydrocarbon mixture comprises n-paraffins and at least two of isoparaffins, cycloparaffins, and aromatics.

The present disclosure provides processes and systems for dehydrating a byproduct stream in ethanol production. In one embodiment, a feed mixture is distilled with one or more distillation units to remove at least a portion of the water, and form a first byproduct stream. The first byproduct stream is contacted with a molecular sieve unit, thereby forming a product stream. The molecular sieve unit is cyclically contacted with at least a portion of the product stream to regenerate the molecular sieve unit and form one or more regenerate streams. A second byproduct stream including at least one of (1) the regenerate streams and (2) at least a portion of the fusel oil stream is contacted with a separation system, thereby forming a permeate and a retentate. At least a portion of the retentate is forwarded into the product stream.

A novel process for making PBI films starting from gel PBI membranes polymerized and casted in the PPA process wherein acid-imbibed gel PBIs are neutralized in a series of water baths and undergo controlled drying in association with a substrate material, yielding a PBI film without the use of organic solvents.

The present disclosure is directed to a forward osmosis system/process utilized primarily in conjunction with a subsurface irrigation system/process. Saline wastewater or naturally saline water is treated using forward osmosis membranes that draw at least partially purified water from the wastewater into an osmotic draw solution (draw solution). The resulting diluted osmotic draw solution is then circulated through the subsurface irrigation system including one or more tubular membranes that reject the draw solution while permitting water in the diluted draw solution to pass through.

A filter assembly for removing a solute from a solvent includes a first annular filter element and a second annular filter element disposed radially inwardly and concentrically aligned with the first filter element together defining a common axis. The first annular filter element is defined by a first annular coil of a flat wire and the second filter element are each defined by a second annular coil of a flat wire being generally helical in the axial direction. A filter membrane is cylindrically shaped and concentrically disposed between the first and second annular filter element. The filter membrane is porous having aperture size of less than a nano-particulate size of the solute, but greater than a nano-particulate size of the solvent. The second annular filter includes adjustable porosity for selectively preventing particles from reaching the filter membrane and selectively cleaning the membrane by reversed flow of solvent through the membrane.

Provided are: an economically superior protein crystallization method capable of efficiently finding conditions for crystallization by using a small amount of protein; and a crystallization device used for the method. According to the present invention, a transparent sealed container 1 is filled with a solution of protein, a part of the transparent sealed container 1 being formed of a semipermeable membrane 2 with a molecular weight cut-off that inhibits passage of the protein while allowing passage of a precipitant, and then, a precipitant solution with changed concentration and/or pH of the precipitant is continuously supplied to the semipermeable membrane 2, to crystallize the protein with the precipitant that infiltrates from the semipermeable membrane 2 into the sealed container 1.

An ion exchange membrane has multiple layers of ionic polymers which each contain substantially different chemical compositions. i.e. varying side chain lengths, varying backbone chemistries or varying ionic functionality. Utilizing completely different chemistries has utility in many applications such as fuel cells where for example, one layer can help reduce fuel crossover through the membrane. Or one layer can impart substantial hydrophobicity to the electrode formulation. Or one layer can selectively diffuse a reactant while excluding others. Also, one chemistry may allow for impartation of significant mechanical properties or chemical resistance to another more ionically conductive ionomer. The ion exchange membrane may include at least two layers with substantially different chemical properties.

Separation of linear and branched alkane isomers via selective permeation through a composite membrane is disclosed. The separation layer in the composite membrane is fabricated from a blend of at least two different fluoropolymer compositions, A and B, in which composition A has a normal-alkane isomer permeability that is greater than composition B. Composition B has a normal alkane to branched-alkane isomer selectivity that is equal or greater than composition A. The separation layer in the composite membrane has a normal-alkane permeability that is greater than composition B and a normal-alkane to branched alkane isomer selectivity that is greater than composition A.