Ngk Insulators, Inc.

Makiko Niino

Kenji Yajima

Tetsuya Uchikawa

Kenichi Noda

Makoto Miyahara

Toshihiro Tomita

Shinji Nakamura

Kunio Nakayama

Miyuki Yabuki

There are provided a process for producing a zeolite membrane which, even when large, has few defects and which has higher separation performance than conventional zeolite membranes, and a zeolite membrane obtained by the process. In the process, the structure-directing agent is removed in the atmosphere having an Oconcentration of 22.0 vol % or more. Specifically, the process includes: a particle adhesion step of allowing zeolite particles functioning as seeds to flow down the surface of the substrate by means of the weight of the slurry itself, thereby adhering to the substrate and a membrane-forming step of forming a zeolite membrane on the substrate by immersing the substrate having the zeolite particles adhering thereto in sol containing the structure-directing agent for hydrothermal synthesis, thereby forming a zeolite membrane on the substrate.

Zeolite membrane and process for producing zeolite membrane

A process for producing a zeolite film is provided in which seed crystals thinly adhere to the surface of a support to form a thin and even zeolite film having fewer defects than conventional zeolite films. Also provided is a zeolite film obtained by the producing process. The process for producing the zeolite film comprises: a particle adhesion step of allowing a slurry, where zeolite particles which become seeds are dispersed, to flow down on the surface of a base material by the self-weight of the slurry, so that the zeolite particles adhere to the base material; and a film formation step of immersing the base material, to which the zeolite particles adhere, into a sol to carry out hydrothermal synthesis, thereby forming the zeolite film on the base material.

Process for producing zeolite film, and zeolite film obtained by the process

Disclosed is a method for producing a DDR zeolite, which can be carried out using materials that are less harmful to the environment. The method for producing a DDR zeolite has a short hydrothermal synthesis time and does not require continuous agitation of the raw material solution. Specifically disclosed is a method for producing a DDR zeolite, which comprises: a raw material solution preparation step in which a raw material solution that contains 1-adamantaneamine, silica (SiO) and water at a molar ratio 1-adamantaneamine/SiOof 0.002-0.5 and a molar ratio water/SiOof 10-500 but does not contain ethylenediamine is prepared; and a crystal growth step in which hydrothermal synthesis is carried out while having the raw material solution and a DDR zeolite powder in contact with each other, so that crystals of DDR zeolite are grown using the DDR zeolite powder as a seed crystal.

Method for producing DDR zeolite

A process for production of a DDR-type zeolite membrane, which comprises: both a seed crystal-forming step of immersing a porous substrate in a seed crystal-forming raw material solution which contains a DDR-type zeolite powder dispersed therein and performing hydrothermal synthesis to form plural DDR-type zeolite crystal particles on surface of the porous substrate, and a membrane-forming step of immersing the resulting porous substrate with DDR-type zeolite crystal particles on the surface in a membrane-forming raw material solution which is free from DDR-type zeolite powder and performing hydrothermal synthesis to form a DDR-type zeolite membrane on the surface of the porous substrate. According to the process, a dense DDR-type zeolite membrane can be formed, and the vessel used in the synthesis can be prevented from being damaged.

Process for the production of DDR-type zeolite membranes

A liquid separation membrane installation body includes a porous base material, and a liquid separation membrane provided on the porous base material, the liquid separation membrane is a porous membrane formed of a dispersant layered inorganic compound, and a membrane thickness of the liquid separation membrane is 0.1 to 1.5 &#x3bc;m. The liquid separation membrane is preferably formed of a sheet-like dispersant layered inorganic compound which has a thickness of 0.1 to 100 nm, a major diameter of 0.01 to 5 &#x3bc;m and an aspect ratio (the major diameter/the thickness) of 3 or more and which is formed into the membrane on the porous base material. There is disclosed the liquid separation membrane installation body capable of increasing a permeation flow rate of a liquid.

Liquid separation membrane installation body

A dehydration method by which water is selectively separated from a water-containing mixturewith a separation membrane. The separation membrane is a DDR type zeolite membrane. The dehydration method includes bringing the mixtureinto contact with one side of the DDR type zeolite membraneand causing a pressure difference between that side of the DDR type zeolite membranewhich is in contact with the mixture and the other side of the DDR type zeolite membraneto thereby cause the water to selectively permeate and separate out. By the dehydration method, water can be selectively separated from a water-containing mixture without the need of a high energy cost. The separation membrane has excellent acid resistance.

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Nagoya, Japan

Makiko Niino