153 results about "Zeolite membranes" patented technology

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.

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.

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.