150 results about "Zeolite membranes" patented technology

Inorganic membrane structures of high stability, high permeability, and large surface area. Zeolite membranes can be disposed onto an intermediate pore size modification layer which reduces the pore size of the inorganic porous support. The intermediate pore size modification layer minimizes the defects in the zeolite membrane and provides a more continuous and uniform zeolite membrane. The inorganic membrane structure can be in the form of a honeycomb monolith. The applications for the zeolite membranes include, for example, membrane ultra-filtration of gas or liquid fluids, biological assays and cell culture surfaces.

Zeolite membrane sheets for separation of mixtures containing water, alcohols, or organics are provided, as well as methods for making the same. Thin, but robust, zeolite membrane sheets having a zeolite membrane layer formed directly on a thin porous metal support sheet provide improved separations performance. The zeolite membrane layers have a thickness less than 3 μm and are formed on a thin porous metal support sheet having a thickness less than or equal to approximately 200 μm. The porous metal support sheet comprises an average pore size of less than 3 μm, a porosity between 25% and 75%, and a thickness of less than or equal to 200 μm.

DDR nanocrystals of uniform size and structure were synthesized using hydrothermal secondary growth and then used to make DDR zeolite membranes and for any other use where uniform, small DDR zeolite crystals are beneficial.

The invention discloses a method for synthesizing silicalite-1 zeolite membranes. The method comprises: preparing synthetic fluid of crystal seeds, performing hydrothermal synthesis for 0.5 to 3 days, obtaining crystal seeds uniform in particle size and preparing a crystal-seed solution; impregnating a carrier with the crystal-seed solution for 5 to 10 seconds, drying and roasting the obtained product; preparing template-free zeolite membrane mother liquor, placing diaphragms containing crystal-seed layers in the mother liquor and performing hydrothermal reaction in a reaction kettle for 4 to 8 hours; and washing and drying membranes. As the synthetic fluid has no template, roasting is not needed after secondary growth, so that defect-free pure silicon zeolite membranes can be obtained. The zeolite membranes are resistant to heat and chemicals, have good stability, and can be applied to the permeation and separation of gas and liquid steam at high temperature and other aspects.

Methods and apparatus are taught for selectively oxidizing carbon monoxide in a source of gas containing carbon monoxide and hydrogen. A gas containing carbon monoxide and hydrogen is fed into a membrane reactor (10, 50, 60) capable of selectively absorbing the carbon monoxide. Preferably, the reactor comprises a substantially defect-free zeolite membrane (4) having at one metal that acts as an oxidation catalyst. The zeolite membrane (4) may be supported on a porous ceramic support (2, 52, 61) and the average pore diameter is preferably between about 0.3 nm and about 1.0 nm. Moreover, the substantially defect-free zeolite membrane (4) preferably has a thickness between about 0.1 micron and about 50.0 microns. The at least one metal is preferably capable of selectively oxidizing the carbon monoxide and is preferably platinum. Preferably, the temperature of reactor housing is maintained at about 200-300° C.

In the carbon dioxide separation system, a mixed gas having a carbon dioxide concentration of 3 to 75% is introduced into a primary carbon dioxide separation device equipped with a zeolite membrane for carbon dioxide separation to produce a primary permeated gas having a carbon dioxide concentration of 80% or more on the permeate side of the zeolite membrane and also reduce the carbon dioxide concentration of a primary gas on the non-permeate side of the zeolite membrane to 3 to 15%. Next, the primary gas on the non-permeate side is introduced into a secondary carbon dioxide separation device that employs an amine absorption method or a pressure swing adsorption (PSA) method to produce a secondary separated gas having a carbon dioxide concentration of 80% or more separated by the separation device and also produce a carbon-dioxide-removed gas having a carbon dioxide concentration of 2% or less.

The invention discloses a method for preparing a NaA type zeolite membrane for ethanol dehydration. NaA type molecular sieves are taken as seed crystals, an ultra-thin uniform seed crystal layer is directly introduced into the surface of a porous support tube, and high-performance NaA type zeolite membranes with different silica-alumina ratios are synthesized by hydrothermal crystallization. The preparation method is implemented by the following steps of introducing a layer of NaA type molecular sieve into the surface of the porous support tube by adopting a hot dipping method, and then introducing a second layer of NaA type molecular sieve to form a dense ultra-thin seed crystal layer by adopting a dip coating method; preparing crystallization mother liquid from silica sol, sodium hydroxide, sodium metaaluminate and de-ionized water; adding the prepared crystallization mother liquid into a stainless steel reaction kettle containing polytetrafluoroethylene, placing the porous support tube pre-planted with seed crystals, and performing hydrothermal synthesis for 4 to 10h at the reaction temperature of 60 to 80 DEG C; taking out the support tube after reaction, washing the support tube with de-ionized water, and drying the support tube at 80 DEG C.

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.

There is provided a zeolite separation membrane-provided article having gaps or pores larger than pores inherent to zeolite crystals and controlled within an appropriate range and being capable of achieving both high permeability and high separability for components with small difference in adsorption properties or a component having a smaller molecular diameter than the diameter of the pores, a method for producing the same, a method for separating mixed fluids, and a device for separating mixed fluids. The zeolite separation membrane-provided article is provided with a zeolite membrane having an N₂ gas permeation speed at room temperature of 1.0×10⁻⁶ mol·m⁻²·s⁻¹·Pa⁻¹ or more and a permeation speed ratio of 1,3,5-trimethylbenzene/N₂ at room temperature of 0.17 or more and being free from dyeing caused by the impregnation with Rhodamine B.

The invention provides a preparation method for mordenite zeolite molecular sieve membranes with high acid resistance. The method directly synthesizes mordenite crystals, and then takes the crystals as crystal seeds, and takes silica sol and aluminum isopropoxide as the source of silicon and aluminum to synthesize dense mordenite zeolite molecular sieve membranes on a porous carrier. The method adopts a tubular support body made of various materials and prepares the mordenite zeolite membranes on a mullite support body. The flux of the membranes prepared on a stainless steel support body is twice higher than that of the membranes prepared on the mullite support body. The synthesized membranes show better stability in the studied acidic media under the different acidity conditions of organic acid and inorganic acid. The method can be widely applied to the pervaporation separation process of an acid system and a reactor for pervaporation membranes.

The invention relates to a FAU-type zeolite membrane that comprises a FAU-type zeolite crystal layer incorporated in the surface porosity of at least one selected face of a porous substrate, in which the ratio between the thickness of said zeolite layer incorporated in the surface porosity of said selected face of the substrate and the total thickness of said zeolite layer is at least 70%. It also relates to processes for preparation and application of these membranes.

The present invention belongs to the field of chemical technology, and is especially one kind of nano silver zeolite film catalyst for gas phase dehydrogenation and oxidation of 1, 2-propylene glycol to synthesize pyruvic aldehyde and its preparation process. The catalyst has nanometer electrolytic silver particle carried onto metal net coated with superthin zeolite film, and is prepared through lamination electrolysis process to deposite electrolytic silver onto zeolite film. The catalyst has low temperature catalytic effect superior to traditional electrolytic silver catalyst and features the continuous catalytic dehydrogenation in the conversion rate up to 96.1 % and selectivity up to 75.6 %.

A method is provided for separating water from an organic solvent which comprises: passing the solvent through at least one conduit within a porous ceramic with a zeolite membrane formed on the internal surface of the conduit; recovering solvent of reduced water content from the conduit; and recovering water which has passed via the membrane through the ceramic to the exterior thereof. The velocity at which the solvent is passed through the conduit induces turbulent flow for scouring solids from the surface of the membrane and reducing or preventing concentration of the organic solvent on the membrane surface e.g. at 1-6 m/s The invention also provides a method of separating water from an organic solvent which comprises: supplying the solvent to first, second and third tanks; circulating solvent between the first tank and zeolite membranes to separate water therefrom; recovering separated water from the membranes; supplying fresh solvent to the second tank; recovering solvent separated of water from the third tank in heat-exchange relationship with solvent supplied to the second tank; and on completion of water separation initiating at least a first new processing cycle in which recovery is from the first tank, circulation is from the second tank and supply is to the third tank. On completion of said first new processing cycle at least a second cycle may be initiated in which supply is to the first tank, recovery is from the second tank and circulation is from the third tank. Apparatus is also provided for separating first and second fluids, comprising: a multiplicity of tubular porous ceramic monoliths having tubular conduits formed within the monolith with a zeolite membrane formed on the internal surface of each of the conduits; first and second support plates each formed with a multiplicity of holes for receiving the ends of the monoliths for supporting said monoliths in spaced parallel relationship, the holes where they open to outer faces of the support plates being formed with counterbores; O-rings in the counterbores for supporting the monoliths in the apertures each at a small clearance from its respective hole; first and second cover plates attached to the first and second support plates and formed with holes corresponding to the holes in the support plate leading to enlarged inwardly facing regions in which ends of the monoliths are received, attachment of the cover plate compressing the O-rings to seal against the monolith; and a housing having a flow passage in which the first and second support Phoenix,002-PCT26 plates are welded; wherein the support plates have outer surfaces machined flat after the support plates have been welded in position.

Disclosed are a heterogeneous zeolite membrane and a method of preparing the same, and more particularly a heterogeneous zeolite membrane that has CHA and DDR zeolite structures by growing seed particles into a crystal structure different from that of the zeolite membrane and can thus separate CO₂/N₂ and CO₂/CH₄ even under wet conditions, 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 preparing a decadodecasil 3R (DDR) type zeolite membrane and a membrane prepared thereby, and more particularly, to a method of preparing a hydrophobic decadodecasil 3R (DDR) type zeolite membrane having a continuous out-of-plane orientation by adding a substrate on which a seed layer is formed to a silica source synthetic precursor containing a methyltropinium salt and performing a hydrothermal synthesis, and a method of capturing and removing carbon dioxide using a membrane prepared thereby.

The invention belongs to the technical fields of wastewater treatment and alcohol-water separation and particularly relates to a preparation method of a separation-purification film for deicing waste liquid of an airplane. The preparation method comprises the following four steps: preprocessing a support body; preparing crystal seeds; depositing the crystal seeds; and synthesizing a zeolite film. According to the preparation method, a layer of dense zeolite film is generated on the surface of a ceramic matrix and is capable of separating the deicing waste liquid. The preparation method is simple in operation, a prepared zeolite coating layer is compact and environment-friendly and has a good binding force, so that the popularization of the preparation method has good social, environmental and economic benefits.

The invention discloses a preparation method for a graphene oxide-NaY zeolite composite membrane, and relates to the technical field of zeolite membranes. The method comprises the following steps thatan NaY zeolite membrane is prepared; the graphene oxide-NaY zeolite composite membrane is prepared, aqueous dispersion of graphene oxide is prepared, and the graphene oxide is introduced on the surface of the NaY membrane; plasma processing and high-temperature solidification are conducted, and the steps are repeated several times to obtain the graphene oxide-NaY zeolite composite membrane. The prepared graphene oxide-NaY zeolite composite membrane can be applied to alcohol dehydration of ethanol dehydration, isopropanol dehydration and the like, dehydration of 50 wt.% acetic acid and dehydration of organic matters widely. The graphene oxide-NaY zeolite composite membrane prepared by adopting the method can effectively strengthen the acid resistance performance of the NaY zeolite membrane, maintain excellent hydrophilia, and solves the problem that a traditional NaY zeolite membrane is poor in acid resistance performance; on the other hand, the graphene oxide on the surface layer canrepair defects of the NaY zeolite membrane layer and be beneficial for improving the separation performance of the graphene oxide-NaY zeolite composite membrane.

A support is a porous ceramic support for supporting a zeolite membrane. The hydraulic conductivity of the support is less than or equal to 1.1×10⁻³ m/s. In the support, the total content of alkali metal and alkaline earth metal in a surface part within 30 μm from a surface in a depth direction perpendicular to the surface is less than or equal to 1% by weight.