The invention provides mixed matrix membranes (MMMs) for olefin/paraffin separation and methodes of making and using the same. The MMMs comprise a continuous polymer matrix with metal doped zeolite nano-particles. A separation technology based upon the composite membranes is effective for propylene and other olefin separation from olefin/paraffin mixtures, and the separation is more energy-efficient than the conventional cryogenic technique.

The present invention relates to a membrane comprising a flat, flexible substrate having a plurality of openings and having a porous inorganic coating situated on and in said substrate, the material of the substrate being selected from woven or non-woven, electrically non-conductive fibers, characterized in that the substrate comprises polyaramide fibers that are pure or connected to fibers of the further polymer or at least of one of these further polymers, wherein the fibers of at least one of said further polymers comprise a melting point that is lower than the decomposition point of the polyaramide fibers.

Prepare a carbon molecular sieve membrane from a polyimide (e.g., a 6FDA/BPDA-DAM polyimide) that has a glass transition temperature of at least 400° C. and includes a bridged phenyl compound for separation of hydrogen and ethylene from one another whether present as a pure mixture of hydrogen and ethylene or as components of a cracked gas. Preparation comprises two sequential steps a) and b). In step a), place a membrane fabricated from defect-free fibers of the polyimide in contact with an oxygen-containing atmosphere under conditions of time and temperature sufficient to produce a pre-oxidized and pre-carbonized polymeric membrane that is insoluble in hot (110 C) n-methylpyrolidone and at least substantially free of substructure collapse. In step b) pyrolyze the pre-oxidized and pre-carbonized membrane in the presence of a purge gas under conditions of time and temperature sufficient to yield a carbon molecular sieve membrane that has at least one of a hydrogen permeance and a hydrogen/ethylene selectivity greater than that of a carbon molecular sieve membrane prepared from the same membrane using only pyrolysis as in step b).

A membrane is described for purifying or separating hydrogen from a multi-component gas stream such as syngas. This membrane uses a molecular pre-treatment, a transition metal, fluorine containing polymer, carbon fibers and carbon matrix sintered on a supportive screen. The membrane may be a bilayer membrane comprised of a layer containing high surface area carbon and another layer containing lower surface area carbon.

Provided herein are methods for making a freeze-cast material having a internal structure, the methods comprising steps of: determining the internal structure of the material, the internal structure having a plurality of pores, wherein: each of the plurality of pores has directionality; and the step of determining comprises: selecting a temperature gradient and a freezing front velocity to obtain the determined internal structure based on the selected temperature gradient and the selected freezing front velocity; directionally freezing a liquid formulation to form a frozen solid, the step of directionally freezing comprising: controlling the temperature gradient and the freezing front velocity to match the selected temperature gradient and the selected freezing front velocity during directionally freezing; wherein the liquid formulation comprises at least one solvent and at least one dispersed species; and subliming the at least one solvent out of the frozen solid to form the material.

A semi-porous composite membrane and a method of manufacturing the semi-porous composite membrane. The semi-porous composite membrane includes a base supporting substrate comprising α-Al.sub.2O.sub.3, an outer layer comprising silica, and an intermediate layer comprising crystalline fibers of boehmite, and at least one of a secondary metal oxide and a synthetic polymer, wherein the intermediate layer is disposed between the base supporting substrate and the outer layer. The crystalline fibers of boehmite are a length of 5-150 nm. The semi-porous composite membrane may be employed in membrane reactors.

An electrochemical compressor utilizes an anion conducting layer disposed between an anode and a cathode for transporting a working fluid. The working fluid may include carbon dioxide that is dissolved in water and is partially converted to carbonic acid that is equilibrium with bicarbonate anion. An electrical potential across the anode and cathode creates a pH gradient that drives the bicarbonate anion across the anion conducting layer to the cathode, wherein it is reformed into carbon dioxide. Therefore, carbon dioxide is pumped across the anion conducting layer. The compressor may be part of a refrigeration system that pumps the working fluid in a closed loop through a condenser and an evaporator.

A filter molded article using a graphene with water passage holes having a desired size is produced in a simple step.

A method for producing a filter molded article having a graphene layer as a filtering material is characterized by including a step of forming a support 3 layer on a surface of a graphene 1 layer formed on initial substrates for a graphene 2 and 9, a step of forming water passage holes in the support 3 layer, a step of removing the initial substrates for a graphene 2 and 9, and a step of forming water passage holes by heating and holding the graphene 1 layer at a low temperature in the air containing oxygen of 160 to 250° C. for a predetermined time.

Disclosed are a CMS membrane, characterized in that it is obtainable by pyrolysis of a polyimide composed of the monomers 1-(4-aminophenyl)-1,3,3-trimethyl-2H-inden-5-amine and 5-(1,3-dioxo-2-benzofuran-5-carbonyl-2-benzofuran-1,3-dione of the following formulae:

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preferably by pyrolysis of the polyimide having the CAS number 62929-02-6, and a supported CMS membrane comprising a CMS membrane obtainable from a polyimide by pyrolysis and a porous support, characterized in that a mesoporous intermediate layer is provided between the CMS membrane and the porous support.

Further disclosed are a process for preparing the supported membrane, the use of the membranes for separating gas mixtures or liquid mixtures, an apparatus for gas separation or for liquid separation, and the use of the polyimide for preparing a CMS membrane by pyrolysis.

Disclosed is a method for producing a hollow fiber carbon membrane using a hollow fiber carbon membrane-forming material by means of a dry method or dry-wet method comprising a spinning step, a drying step, an infusibilization step, and a carbonization step as basic steps; wherein in the infusibilization step, heat treatment is performed at least two times at different temperatures, with the second temperature being higher than the first temperature. It is preferable that the second heat treatment is performed directly after the first treatment is performed, without once cooling to room temperature. The obtained hollow fiber carbon membrane has improved permeability, without reducing its separation coefficient.