Abstract: There is provided a process for producing a DDR-type zeolite having: a raw material solution preparation step of preparing a raw material solution containing 1-adamantaneamine hydrochloride, silica (SiO2), and water at a 1-adamantaneamine hydrochloride/SiO2 molar ratio of 0.002 to 0.5 and a water/SiO2 molar ratio of 10 to 500, and a crystal growth step of subjecting the raw material solution and a DDR-type zeolite powder to a heat treatment in a state that both the raw material solution and the DDR-type zeolite powder are brought into contact with each other to grow crystals of the DDR-type zeolite by the use of the DDR-type zeolite powder as seed crystals.

Abstract: 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.

Abstract: A method is provided for producing a DDR type zeolite membrane, including a membrane formation step of immersing a porous substrate having a DDR type zeolite seed crystal adhered thereon, in a raw material solution containing 1-adamantaneamine, silica (SiO2) and water, and conducting a hydrothermal synthesis of DDR type zeolite to form a 1-adamantaneamine-containing DDR type zeolite membrane on the porous substrate to produce a precursor of DDR type zeolite membrane-containing body, and a burning step of heating the precursor at 400° C. or above and at 550° C. or below to burn and remove the 1-adamantaneamine contained in the DDR type zeolite membrane.

Abstract: 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 O2 concentration 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.

Abstract: A method for manufacturing a DDR zeolite membrane element including the steps of: immersing a porous substrate in a raw material solution, forming a DDR zeolite membrane containing 1-adamanthanamine on a surface of the porous substrate by subjecting a DDR zeolite to hydrothermal synthesis in the presence of DDR zeolite seed crystals, applying a glass paste onto the surface of the porous substrate so as to contact the membrane, and heating the membrane at 500 to 800° C., thereby burning away the 1-adamanthanamine contained in the membrane and melting the glass paste to form a membrane-like glass seal contacting the membrane on the surface of the porous substrate. The method for manufacturing a DDR zeolite membrane element can inhibit the permeation of the DDR zeolite membrane from being hindered in a contact portion between the membrane and the glass seal and inhibit poor seal of the glass seal.

Abstract: There is provided a process for producing a DDR-type zeolite having: a raw material solution preparation step of preparing a raw material solution containing 1-adamantaneamine hydrochloride, silica (SiO2), and water at a 1-adamantaneamine hydrochloride/SiO2 molar ratio of 0.002 to 0.5 and a water/SiO2 molar ratio of 10 to 500, and a crystal growth step of subjecting the raw material solution and a DDR-type zeolite powder to a heat treatment in a state that both the raw material solution and the DDR-type zeolite powder are brought into contact with each other to grow crystals of the DDR-type zeolite by the use of the DDR-type zeolite powder as seed crystals.

Abstract: 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.

Abstract: There is provided a DDR-type zeolite powder composed of fine particles and exhibits a particle size distribution where the majority of the particles have particle diameters converging in the vicinity of the mean particle diameter, and a process for the production of the same. Specifically provided is a process for the production of a DDR-type zeolite powder, which comprises a step of heat-treating a raw material solution at 100 to 180° C., and thereby growing crystals until the mean particle diameter reaches to a level of 0.1 ?m or more and below 2.5 ?m.

Abstract: A porous substrate with a seed crystal-containing layer for manufacturing a zeolite membrane includes: a ceramic porous substrate, and a seed crystal-containing layer containing a zeolite powder to function as a seed crystal for forming a zeolite membrane and a ceramic powder and being loaded on a surface of the ceramic porous substrate and fired to fix the seed crystal-containing layer on the porous substrate. The porous substrate with a seed crystal-containing layer used for manufacturing a zeolite membrane inhibits a defect such as a crack from being generated in the zeolite layer upon manufacture or use by manufacturing a zeolite membrane by the use of the substrate which then can be subjected to air-spraying, washing, and processing for the purpose of removing a foreign substance, etc., prior to hydrothermal synthesis.

Abstract: A method for manufacturing a DDR zeolite membrane element including the steps of: immersing a porous substrate in a raw material solution, forming a DDR zeolite membrane containing 1-adamanthanamine on a surface of the porous substrate by subjecting a DDR zeolite to hydrothermal synthesis in the presence of DDR zeolite seed crystals, applying a glass paste onto the surface of the porous substrate so as to contact the membrane, and heating the membrane at 500 to 800° C., thereby burning away the 1-adamanthanamine contained in the membrane and melting the glass paste to form a membrane-like glass seal contacting the membrane on the surface of the porous substrate. The method for manufacturing a DDR zeolite membrane element can inhibit the permeation of the DDR zeolite membrane from being hindered in a contact portion between the membrane and the glass seal and inhibit poor seal of the glass seal.

Abstract: A dehydration method by which water is selectively separated from a water-containing mixture 31 with a separation membrane. The separation membrane is a DDR type zeolite membrane 2. The dehydration method includes bringing the mixture 31 into contact with one side of the DDR type zeolite membrane 2 and causing a pressure difference between that side of the DDR type zeolite membrane 2 which is in contact with the mixture and the other side of the DDR type zeolite membrane 2 to 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.

Abstract: A method for producing a DDR type zeolite membrane, which method comprises a membrane formation step of immersing a porous substrate having a DDR type zeolite seed crystal adhered thereon, in a raw material solution containing 1-adamantaneamine, silica (SiO2) and water, and conducting a hydrothermal synthesis of DDR type zeolite to form a 1-adamantaneamine-containing DDR type zeolite membrane on the porous substrate to produce a precursor of DDR type zeolite membrane-containing body, and a burning step of heating the precursor at 400° C. or above and at 550° C. or below to burn and remove the 1-adamantaneamine contained in the DDR type zeolite membrane.

Abstract: A gas separator is provided, including a porous substrate made of a first ceramic and a gas-separating layer containing zeolite disposed on the surface of the porous substrate. The gas-separating layer further contains, in addition to zeolite, a thermal expansion coefficient-adjusting material made of a second ceramic having a linear thermal expansion coefficient satisfying a predetermined relationship, so that the difference between the thermal expansion coefficient of the porous substrate and the gas-separating layer can be reduced.

Abstract: A dehydration method by which water is selectively separated from a water-containing mixture 31 with a separation membrane. The separation membrane is a DDR type zeolite membrane 2. The dehydration method includes bringing the mixture 31 into contact with one side of the DDR type zeolite membrane 2 and causing a pressure difference between that side of the DDR type zeolite membrane 2 which is in contact with the mixture and the other side of the DDR type zeolite membrane 2 to 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.

Abstract: A method for producing a DDR type zeolite membrane, comprising immersing a porous substrate in a raw material solution containing 1-adamantanamine, silica, and water; and carrying out a hydrothermal synthesis of DDR type zeolite in the presence of a DDR type zeolite seed crystal (seed crystal) to form a DDR type zeolite membrane on the surface of the porous substrate by making a content ratio of 1-adamantanamine to silica (1-adamantanamine/silica) in the range of 0.002 to 0.4 in terms of molar ratio and a content ratio of water to silica (water/silica) in the range of 10 to 500 in terms of molar ratio, and an average particle diameter of the seed crystal to 300 nm or less to provide a method for producing stably a DDR type zeolite membrane of uniform and thin membrane thickness with high gas permeability.

Abstract: A porous substrate with a seed crystal-containing layer for manufacturing a zeolite membrane includes: a ceramic porous substrate, and a seed crystal-containing layer containing a zeolite powder to function as a seed crystal for forming a zeolite membrane and a ceramic powder and being loaded on a surface of the ceramic porous substrate and fired to fix the seed crystal-containing layer on the porous substrate. The porous substrate with a seed crystal-containing layer used for manufacturing a zeolite membrane can inhibit a defect such as a crack from being generated in the zeolite layer upon manufacture or use by manufacturing a zeolite membrane by the use of the substrate and can be subjected to air-spraying, washing, and processing for the purpose of removing a foreign substance, etc., prior to hydrothermal synthesis.

Abstract: The present invention discloses a gas separator comprising a porous substrate composed of a first ceramic and a gas-separating layer containing zeolite, disposed on the surface of the porous substrate, wherein the gas-separating layer contains, in addition to zeolite, a thermal expansion coefficient-adjusting material composed of a second ceramic having a linear thermal expansion coefficient satisfying a predetermined relation so that the difference in thermal expansion coefficient between the porous substrate and the gas-separating layer can be reduced. The gas separator of the present invention can be used preferably particularly in selective separation of carbon dioxide (CO2) or the like from a mixed gas such as natural gas or the like.

Abstract: A DDR type zeolite membrane formed on a substrate includes silica as a main component. The DDR type zeolite membrane separates at least one type of a gas component from a mixed gas containing at least two types of gases selected from a group consisting of carbon dioxide (CO2), hydrogen (H2), oxygen (O2), nitrogen (N2), methane (CH4), normal butane (n-C4H10), isobutane (i-C4H10), sulfur hexafluoride (SF6), ethane (C2H6), ethylene (C2H4), propane (C3H8), propylene (C3H6), carbon monoxide (CO), and nitrogen monoxide (NO). Each single gas permeance at room temperature and 100° C. are different, respectively, in order to separate at least one selected gas component from the mixed gas.

Abstract: A DDR type zeolite membrane formed on a substrate includes silica as a main component. The DDR type zeolite membrane separates at least one type of a gas component from a mixed gas containing at least two types of gases selected from a group consisting of carbon dioxide (CO2), hydrogen (H2), oxygen (O2), nitrogen (N2), methane (CH4), normal butane (n-C4H10), isobutane (i-C4H10), sulfur hexafluoride (SF6), ethane (C2H6), ethylene (C2H4), propane (C3H8), propylene (C3H6), carbon monoxide (CO), and nitrogen monoxide (NO). Each single gas permeance at room temperature and 100° C. are different, respectively, in order to separate at least one selected gas component from the mixed gas.

Abstract: This invention provides a DDR type zeolite membrane, characterized in that it is formed as a membrane on a substrate and its main component is silica, and that each single gas permeance at room temperature and 100° C. are different, respectively among at least two types of gases selected from a group consisting of carbon dioxide (CO2), hydrogen (H2), oxygen (O2), nitrogen (N2), methane (CH4), normal butane (n-C4H10), isobutane (i-C4H10), sulfur hexafluoride (SF6), ethane (C2H6), ethylene (C2H4), propane (C3H8), propylene (C3H6), carbon monoxide (CO), and nitrogen monoxide (NO).