660 results about "Large pore size" patented technology

The propylene production of a fluid catalytic cracking unit employing a large pore zeolite cracking catalyst, produces more propylene by adding a naphtha cracking riser and a medium pore zeolite catalytic component to the unit, and recycling at least a portion of the naphtha crackate to the naphtha riser. The large pore size zeolite preferably comprises a USY zeolite and the medium pore size is preferably ZSM-5. Propylene production per unit of naphtha feed to the naphtha riser is maximized, by using the 60-300.degree. F. naphtha crackate as the feed.

Porous membranes having a micro phase separation structure and showing a light transmittance at the wavelength of 400 nm of not less than 30% are obtained by the dry phase conversion method comprising drying a coating layer of a dope containing a polymer, a good solvent for the polymer and a poor solvent for the polymer which solvent has a higher boiling point than the good solvent. The polymer includes cellulose derivatives, vinyl-series polymers such as acrylonitrile-series polymers and (meth)acrylic acid ester-series polymers, polysulfone-series polymers, and the like. The porous polymer membranes have a porosity of 10 to 60%, a mean pore size of about 0.002 to 0.35 mum and a maximum pore size of not greater than 0.4 mum. These porous membranes shows not only excellent transparency but also high productivity.

The present invention relates to a pseudothin diaspore composition containing organic pore-expanding agent. Said composition contains 92-99.5 wt% of pseudothin diaspore and 0.5-8 wt% of organic pore-expanding agent, in which the crystallinity of pseudothin diaspore is 10-70%. In the pseudothin diaspore composition provided by said invention the organic pore-expanding agent content is low, after high-temperature calcination the alumina with large pore capacity and large pore diameter can be obtained. Said alumina can be used as carrier material for preparing hydrodemetalization catalyst for heavy oil, residual oil and short residuum specially.

A process for isomerization dewaxing of a hydrocarbon feed which includes contacting the hydrocarbon feed with a large pore size, small crystal size, crystalline molecular sieve and an intermediate pore size, small crystal size, crystalline molecular sieve to produce a dewaxed product with a reduced pour point and a reduced cloud point. In a preferred embodiment, the feed is contacted with the molecular sieves sequentially, first with the large pore sieve followed by the intermediate pore sieve.

The sulfur content of liquid cracking products, especially the cracked gasoline, of the catalytic cracking process is reduced by the use of a sulfur reduction additive comprising a porous molecular sieve which contains a metal in an oxidation state above zero within the interior of the pore structure of the sieve. The molecular sieve is normally a large pore size zeolite such as USY or zeolite beta or an intermediate pore size zeolite such as ZSM-5. The metal is normally a metal of Period 4 of the Periodic Table, preferably zinc or vanadium. The sulfur reduction catalyst may be used in the form of a separate particle additive or as a component of an integrated cracking/sulfur reduction catalyst.

The invention discloses a three-dimensional printing molding preparation method for a porous ceramic for filtration. The method comprises the following steps: S1 preparing a ceramic material for printing in a three-dimensional printer; S2 printing a porous ceramic green body through the three-dimensional printer by using the prepared printing ceramic material; and S3; conducting drying, rubber discharging and sintering on the printed porous ceramic green body to obtain a porous ceramic with a specific shape structure. The three-dimensional printing molding preparation method has the beneficial effects that ceramic particles are loose in connection, the density of the ceramic green body is low, the shrinkage rate after sintering is large, and the defects such as deformation and cracking are easy to occur, and the mechanical properties of the prepared products are lower; and a generated loose porous structure has larger pore size in pores, and the pore size and porosity are difficult to control through a molding process parameter. The ceramic material for printing according to the invention fully mixes solid powder with liquid additive, the ceramic particles are connected closely and the components are uniform, and the printed ceramic green body has high precision and good mechanical performance.

The present invention is preparation process of plate microporous composite polyvinylidene fluoride film. The preparation process includes: mounting the support layer on composite film scraping machine and regulating the cloth speed; regulating the interval between the support layer and the scraper with plug gage; feeding filming liquid into the film scraping machine and coating the liquid to the support layer to form film, running the film in the air for some time, soaking the film in solidifying bath to form the composite film of polyvinylidene fluoride and the support layer. The composite film features large pore size, high strength and high water flux. The composite film is measured to have pore size of 0.1-1.5 micron, pure water flux of 400-2100 L/hr.sq m (at 0.1MPa), thickness of 150-220 microns, radial tensile strength of 35.2 MPa, radial elongation at breaking of 51.92 %, transverse tensile strength of 18.2 MPan and transverse elongation at breaking of 68.7 %.

A hydrophilic microporous membrane comprising a thermoplastic resin, having been subjected to hydrophilizing treatment and having a maximum pore size of 10 to 100 nm, wherein when 3 wt % bovine immunoglobulin having a monomer ratio of 80 wt % or more is filtered at a constant pressure of 0.3 MPa, an average permeation rate (liter/m²/h) for 5 minutes from the start of filtration (briefly referred to as globulin permeation rate A) satisfies the following formula (1) and an average permeation rate (liter/m²/h) for 5 minutes from the time point of 55 minutes after the start of filtration (briefly referred to as globulin permeation rate B) satisfies the following formula (2):

Globulin permeation rate A>0.0015×maximum pore size (nm)^2.75   (1)

Globulin permeation rate B/globulin permeation rate A>0.2   (2).

The invention relates to a preparation method of a three dimensional graded porous activated carbon material, the method is as follows: a chemical activator itself is used as a template hole forming agent, on the basis of formation of pore channel in the chemical activator, micropores and mesopores are further formed by corrosion, and eventually the three dimensional graded porous activated carbon material simultaneously having macropores, mesopores and micropores is formed. The activated carbon material prepared by the method has a very large specific surface area, a mutually-comunicated porous structure, larger pore size and high conductivity. The material can be widely used as electrode materials, adsorption materials, catalysts, catalyst carriers, hydrogen storage materials, electric adsorption desalting electrode materials and the like of energy storage devices; the preparation method of the three dimensional graded porous activated carbon material has the advantages of simple operation and low cost, and is convenient for industrial production.

The invention relates to a polylactic acid foamed material and a preparation method thereof. The invention solves the technical problems of large pore size, nonuniformity and high porosity in the existing product. The polylactic acid foamed material is prepared by an extrusion foaming method. The polylactic acid foamed material comprises polylactic acid, at least one biodegradable polyester (selected from poly(butylenes succinate), polyhydroxybutyrate, polycaprolactone and copolymer or blend thereof), a physical foaming agent, and at least one processing assistant for foaming. The apparent density of the microporous foamed sheet is 0.05-0.5g/cm<3>, the average pore diameter is not greater than 100 micrometers, and the porosity is not greater than 10%. The invention is mainly used in the fields of food packaging, automobile industry and the like.

A water tank filter having a double structure including an inner filter having a small pore size for trapping fine particles of filth from tank water and situated within a hollow outer filter having a large pore size for trapping coarse particles of filth. The inner filter is situated in roughly the upper half of the internal space of the outer filter. Disclosed also is a water tank purifier including the water tank filter. The water tank filter and purifier can effectively remove both coarse and fine particles of filth from a water tank. The filter does not quickly get clogged, and is easy to handle.

The invention relates to a method for producing a small-aperture ceramic membrane. The invention can produce a small-aperture ceramic ultrafiltration membrane on the surface of a support with an aperture of 50- 200 nm. The method comprises the following steps: treating the surface of the support with larger pore size with organic solution, covering the surface with coating solution with smaller sole particle size, allowing rapid gelatination of the coating under constant-temperature and constant-humidity conditions, preventing leakage of the sol, sun-drying or oven-drying the coating, and removing organic substances by means of solvent extraction or direct calcination, to obtain the small-aperture ceramic membrane. The produced small-aperture ceramic membrane doesn't be affected by the support. The production cycle of the membrane is short with low cost.

The invention relates to a preparation method of large pore volume and large pore diameter silica. With industrial water glass as silica source, water soluble polymer and surfactant as hydrophobic agent and hole forming template, by controlling reaction conditions such as temperature, hydrophobic agent, final ph value, etc., the large pore volume silica products are produced; the pore diameter is narrowly distributed, the pore volume is between 2-2.5cm3/g and the average pore diameter is between 18-35 nm. Especially, the more optimal three-step heating regulation is more beneficial to the stability of hole forming and hole structure and that the distribution of pore diameter reaches between 25-35nm is more proper to be used as flatting agent.

The invention discloses three-dimensionalgraphene composite aerogel. High-molecular material nano fiber with a biomass polysaccharide structure is compounded with oxidized graphene through a surface electrostatic-force effect, and then the composite aerogelis prepared by utilizing hydrazine hydrate reduction and a method for high-temperature pyrolysis in an inert atmosphere. The invention further discloses a preparation method of the three-dimensionalgraphene composite aerogel. The method for preparing the three-dimensionalgraphene composite aerogel is simple, easy to operate, large in specific surface area, uniform in pore size distribution and good in electrical conductivity, and the chemical reactivity is improved.

The invention discloses a method for large-area preparation of a hydrophobic/hydrophilic Janus composite fiber membrane with a function of efficient catchment under drive of directional capillary force through electrostatic spinning and belongs to the technical field of functional fiber materials. A continuous winding device is taken as an electrospinning receiving substrate, a large-area Janus composite fiber membrane material with directional capillary function and hydrophobic/hydrophilic wettability difference is obtained by regulating and matching pore sizes forming two membranes of the hydrophobic/hydrophilic Janus composite fiber membrane and selecting different wettable polymer materials and is applied to collection and catchment of tiny water drops in the air. The preparation method is simple, low in energy consumption and high in efficiency and can realize stable large-area preparation. According to the prepared composite fiber membrane, tiny water drops are more easily caughtand absorbed when penetrating through a microporous hydrophilic layer from a microporous hydrophobic layer, so that the composite fiber membrane has higher tiny water drop collection capability thanfiber membranes with water drops penetrating from the microporous hydrophilic layer to the microporous hydrophobic layer as well as having a pure hydrophilic property and a pure hydrophobic property.