Abstract: A zeolite crystal has an AFX structure and a hexagonal plate shape. Ratio of a maximum Feret diameter (L1) in a plan view with respect to a plate thickness in a side view is greater than or equal to 2.

Abstract: A peak intensity of a (110) plane is greater than or equal to 2.5 times a peak intensity of a (004) plane in an X-ray diffraction pattern obtained by irradiation of X-rays to a membrane surface of the AFX membrane.

Abstract: A peak intensity of a (004) plane is greater than or equal to 3 times a peak intensity of a (110) plane in an X-ray diffraction pattern obtained by irradiation of X-rays to a membrane surface of an AFX membrane.

Abstract: A method of synthesis for an aluminophosphate-based zeolite membrane includes a steps of preparing a mixed solution with a pH greater than or equal to 6 and less than or equal to 9 by mixing an acidic phosphorous source with an alkali source, a steps of preparing a starting material solution by adding and mixing an aluminum source to the prepared mixed solution, and a steps of synthesizing an aluminophosphate-based zeolite membrane by hydrothermally synthesizing the starting material solution.

Abstract: A peak intensity of a (002) plane is greater than or equal to 0.5 times a peak intensity of a (100) plane in an X-ray diffraction pattern obtained by irradiation of X-rays to a membrane surface of the ERI membrane.

Abstract: A method for manufacturing a zeolite membrane structure comprises an immersion step for immersing a porous substrate in a synthetic sol, and a synthesis step for hydrothermally synthesizing a zeolite membrane on a surface of the porous substrate that has been immersed in the synthesis so. When the foamability of the synthetic sol is measured by a Ross-Miles method under a condition of 25 degrees C., the foam height after elapse of 5 minutes from completion of down flow is less than or equal to 5 mm.

Abstract: A process for producing a zeolite membrane composite includes a step of obtaining FAU-type seed crystals, a step of depositing the FAU-type seed crystals on a support, a step of forming an AFX-type zeolite membrane on the support by immersing the support in a raw material solution and growing an AFX-type zeolite from the FAU-type seed crystals by hydrothermal synthesis, and a step of removing a structure-directing agent from the AFX-type zeolite membrane. In this way, the AFX-type zeolite membrane can be provided.

Abstract: A method for inspecting a separation membrane structure includes an assembly step of sealing a separation membrane structure that includes a porous substrate and a separation membrane into a casing, and an inspection step of applying pressure to an inspection liquid that has filled a first main surface side of the separation membrane.

Abstract: A separation membrane structure includes a porous support, a first separation membrane and a second separation membrane. The first separation membrane is formed on the porous support and contains high silica zeolite having Si/Al atomic ratio of greater than or equal to 200. The second separation membrane is formed on the first separation membrane and contains cation.

Abstract: A monolithic substrate comprises a porous base material body, a first support portion, a first cell seal portion, a second support portion, and a second cell seal portion. The base material body includes a plurality of cells respectively passing from a first end surface to a second end surface. The first support portion contains ceramics as an aggregate material, and is packed into the first end portion of a seal target cell. The first cell seal portion contains glass, and is disposed on an outer surface of the first support portion. The second support portion contains ceramics as an aggregate material, and is packed into the second end surface of the seal target cell. The second cell seal portion contains glass, and is disposed on an outer surface of the second support portion.

Abstract: A monolithic separation membrane structure comprises a porous monolithic substrate and a separation membrane. The monolithic substrate includes a first end surface, a second end surface and a plurality of through-holes respectively passing from the first end surface to the second end surface. The separation membrane is formed on an inner surface of the respective plurality of through-holes. The surface roughness Ra of the separation membrane is no more than 1 micrometer and the thickness of the separation membrane is no more than 5 micrometers.

Abstract: 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 CF4 by a permeance of CO2 to be 0.015 or less, and has fewer defects.

Abstract: Each cell is pressurized with gas from outside of the cell, the amount of permeation of the gas permeated into each cell is measured, and a cell having the amount of permeation greater than (average value of all cells+A) (wherein A is a predetermined value of ? to 6?, where ? is the standard deviation) is considered to be defective. Alternatively, pressure is reduced for each cell, the degree of vacuum in each cell is measured, and a cell having the degree of vacuum worse than (average value of all cells+A) is considered to be defective. Then, a polymer compound is poured into the defective cells of the monolithic separation membrane structure and cured so that the defective cells are sealed. Alternatively, the polymer compound formed in advance as the sealing member is inserted into the defective cells to seal the defective cells.

Abstract: A separation membrane structure comprising a porous support, a first glass seal, and a separation membrane. The porous support includes through-holes which connect a first end surface and a second end surface. The first glass seal is configured to cover the first end surface. The separation membrane is formed on an inner surface of the through-holes. The first glass seal has a first seal body part and a first extension part. The first seal body part is disposed on the first end surface. The first extension part is connected to the first seal body part and disposed on the inner surface of the through-holes. The separation membrane has a first connection part connected to the first extension part of the first glass seal. A first thickness of the first connection part is less than or equal to 10 microns, and less than or equal to 3.2 times a center thickness at a longitudinal center of the separation membrane.

Abstract: A production method for zeolite powder containing forming zeolite seed crystals by wet pulverizing zeolite crystals using a silica unsaturated alkali solution containing an alkali source, preparing a silica saturated alkali solution by adding a silica source to the silica unsaturated alkali solution containing the zeolite seed crystals, and synthesizing zeolite powder by hermetically heating the silica saturated alkali solution.

Abstract: A production method for zeolite powder includes disintegrating zeolite seed crystals in a silica unsaturated alkali solution containing an alkali source, preparing a silica saturated alkali solution by adding a silica source to the silica unsaturated alkali solution containing the zeolite seed crystals, and synthesizing zeolite powder by hermetically heating the silica saturated alkali solution.

Abstract: A porous support includes a base body, a supporting layer, and a topmost layer. The supporting layer is disposed between the base body and the topmost layer, and makes contact with the topmost layer. A ratio of a porosity of the topmost layer to a porosity of the supporting layer is greater than or equal to 1.08. A ratio of a thickness of the topmost layer to a thickness of the supporting layer is less than or equal to 0.9.

Abstract: There are provided DDR type zeolite seed crystals capable of inhibiting generation of surplus DDR type zeolite crystals in the case of using the DDR type zeolite seed crystals as seed crystals upon forming a DDR type zeolite membrane on the surface of a porous support. The DDR type zeolite seed crystals have an average particle size of 0.05 to 1.5 ?m; contain 90% or more of particles having an aspect ratio, which is obtained by dividing the maximum Feret's diameter by the minimum Feret's diameter, of 1 to 3; and have not more than 0.3 of a coefficient of variation of the square of the aspect ratio.

Abstract: A ceramic separation membrane structure in which a zeolite separation membrane formed on a ceramic porous body is repaired, and a repair method thereof. In the ceramic separation membrane structure, a zeolite separation membrane is disposed on a ceramic porous body, and defects of the zeolite separation membrane are repaired by zeolite repaired portions containing zeolite of structure different from the structure of zeolite of the zeolite separation membrane. The zeolite separation membrane and the zeolite repaired portions are made of a hydrophobic zeolite having a ratio of SiO2/Al2O3=100 or more.

Abstract: A separation membrane structure comprising a porous support, a first glass seal, and a separation membrane. The porous support includes through-holes which connect a first end surface and a second end surface. The first glass seal is configured to cover the first end surface. The separation membrane is formed on an inner surface of the through-holes. The first glass seal has a first seal body part and a first extension part. The first seal body part is disposed on the first end surface. The first extension part is connected to the first seal body part and disposed on the inner surface of the through-holes. The separation membrane has a first connection part connected to the first extension part of the first glass seal. A first thickness of the first connection part is less than or equal to 10 microns, and less than or equal to 3.2 times a center thickness at a longitudinal center of the separation membrane.