An object of the present invention is to provide a porous support-zeolite membrane composite ensuring that at the time of separation or concentration with a zeolite membrane, both sufficient throughput and high separation performance are achieved in practice and the present invention relates to a porous support-zeolite membrane composite having a porous support and a zeolite membrane formed on the porous support, wherein part of the zeolite membrane penetrates into the inside of the porous support and the distance from the surface of the porous support to the inside into which the zeolite film penetrates is 5.0 m or less on average.

Provided are an all-silica zeolite separation membrane for separating carbon dioxide, etc., and not causing a decrease in the processing amount due to adsorption of water molecules, and a production method therefor. One aspect of the present invention is a zeolite separation membrane, in which the framework of a zeolite crystal structure formed on a porous support is all silica, characterized in that the zeolite crystal structure formed on the porous support is fluorine free. Another aspect of the present invention is a method for producing a zeolite separation membrane having a zeolite crystal structure on a porous support, characterized in that the method includes a step of producing a seed crystal, a step of applying the seed crystal onto the porous support, a step of producing a membrane synthesis raw material composition, and a step of immersing the porous support having the seed crystal applied thereon in the membrane synthesis raw material composition and performing hydrothermal synthesis, and the membrane synthesis raw material composition contains a silica source and an organic template and does not contain a fluorine compound.

The present invention aims at providing a method for producing a high-concentration alcohol from a water-alcohol mixture, in which the overall process is efficient and the present invention relates to a production method of a high-concentration alcohol, including a water adsorption step of adsorbing water of a water-alcohol mixture on an adsorption column to obtain a first concentrated alcohol, a water desorption step of introducing an alcohol to obtain a hydrous alcohol, and a membrane separation step of introducing the hydrous alcohol into a membrane separation unit provided with a membrane composite containing zeolite having an SiO.sub.2/Al.sub.2O.sub.3 molar ratio of 5 to 15 to obtain a second concentrated alcohol.

Provided is a method for producing a separation membrane including a silicalite membrane without using NaOH or the like that causes an increase in cost with respect to equipment, facilities, and process time. The method for producing a separation membrane is a method for producing a separation membrane including a porous support and a silicalite membrane that is formed on the support and has an MFI-type zeolite crystal structure, and is characterized in that the method includes a step of producing a seed crystal, a step of attaching the seed crystal onto the porous support, a step of producing a membrane synthesis raw material composition containing SiO.sub.2, an organic template, and H.sub.2O, and a step of immersing the porous support having the seed crystal attached thereto in the membrane synthesis raw material composition and performing hydrothermal synthesis, and the composition ratio of the membrane synthesis raw material composition is as follows: SiO.sub.2:organic template:H.sub.2O=1:(0.05 to 0.15):(50 to 120).

Embodiments include methods of fabricating a zeolite-like metal-organic framework with an ana-topology (ana-ZMOF) thin film membrane, the methods comprising: (1) modifying a substrate with ana-ZMOF crystal precursors in the presence of polyvinylpyrrolidone; and (2) intergrowing the ana-ZMOF crystal precursors in the presence of polyvinylpyrrolidone to form a continuous defect-free thin film of an ana-ZMOF intergrown on the substrate. Embodiments further include methods of separating chemical species comprising contacting an ana-ZMOF thin film membrane with a fluid composition containing one or more chemical species and separating at least one of the chemical species.

The present invention relates to a method of fabricating an organic structure directing agent-free CHA type zeolite membrane and a membrane fabricated thereby, and more particularly to a method of fabricating a continuous CHA type zeolite membrane, which exhibits CO.sub.2/N.sub.2 and CO.sub.2/CH.sub.4 separation performances comparable with those of conventional membranes, in a cost-effective manner without a calcination process by hydrothermal synthesis using an alkali metal hydroxide without using an organic structure directing agent, and to a membrane fabricated thereby.

Provided is a zeolite membrane manufactured by: subjecting a porous body to heat treatment at 400? C. or more in the presence of oxygen as pretreatment, before adhering zeolite seed crystals to a surface of the porous body; storing the porous body under an environment of humidity of 30% or more for 12 hours or more after the heat treatment; and subsequently adhering the zeolite seed crystals to the porous body. The zeolite membrane having oxygen eight-membered rings, which is manufactured by subjecting the porous body to the heat treatment, provides a value that is obtained by dividing a permeance of CF.sub.4 by a permeance of CO.sub.2 to be 0.015 or less, and has fewer defects.

Water permeable coated substrates comprising a polymeric substrate in contact with a coating comprising a plurality of particles and a cross-linked polymer are disclosed. Uses of the coated substrates, particularly for water filtration are also disclosed.

Disclosed are a CHA zeolite membrane and a method of preparing the same, and more particularly, a CHA zeolite membrane having high capacity to separate CO.sub.2/N.sub.2 and CO.sub.2/CH.sub.4 even under wet conditions using a membrane produced using a synthetic precursor having a controlled ratio of Si and Al, a method of preparing the same, and a method of capturing and removing carbon dioxide using the membrane.

The present invention relates to a method of controlling a defect structure in an MFI zeolite membrane and a method of separating xylene isomers using the MFI zeolite membrane produced by the method, and more particularly, to a method of controlling a defect structure in an MFI zeolite membrane that improves the performance of separating a xylene isomer by reducing the amount and size of defects formed in the MFI membrane structure when removing organic-structure-directing agents in the membrane through calcination at a low temperature using ozone.