2479 results about "Large pore" patented technology

A honeycomb structured body of the present invention is a honeycomb structured body in which a plurality of porous ceramic members are combined with one another through an adhesive layer, each of the porous ceramic members having a plurality of cells which are allowed to penetrate in a longitudinal direction with a wall portion therebetween and either one end of which is sealed, with a catalyst supporting layer being adhered to said wall portion, wherein pores formed in said porous ceramic member are constituted by large pores having a relatively large pore diameter and small pores having a relatively small pore diameter, and supposing that: the thickness of the catalyst supporting layer is X₁ (μm), and the value, obtained by multiplying the porosity (%) of said porous ceramic member by the ratio (the average pore diameter of said large pores/the average pore diameter of said small pores) of the average pore diameter of said large pores to the average pore diameter of said small pores, is Y₁, these X₁ and Y₁ are allowed to satisfy the following inequalities (1) and (2):

6X₁+80.5≦Y₁≦6X₁+230.5  (1)

6X₁+330≦Y₁≦−6X₁+474  (2).

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.

An acidic amorphous silica-amumina has a large specific surface area and a large pore volume. A carrier complex and a hydrotreating catalyst containing acidic amorphous silica-alumina, in particular a hydrocracking catalyst containing acidic amorphous silica-alumina in combination with a modified zeolite-Y, treats petroleum hydrocarbon materials to produce middle distillates. The amorphous silica-alumina has a SiO2 content of 10-50 wt. %, a specific surface area of 300-600 m2/g, a pore volume of 0.8-1.5 ml/g and an IR acidity of 0.25-0.60 mmol/g. The catalyst shows a relatively high activity and mid-distillate selectivity and can be particularly used in hydrocracking process for producing mid-distillates with a higher yield.

The invention discloses preparation methods for a macroporous alumina carrier and a hydrodemetallization catalyst. The preparation method for the macroporous alumina carrier includes the following steps: (1) dry pseudoboehmite gel powder is hydrothermally processed under high pressure; (2) the dry pseudoboehmite gel powder obtained in step 1 is kneaded into a plastic, and pore-expanding agent is added in step 1 or step 2; (3) the plastic obtained in step 2 is shaped, the shaped material is dried and baked, and thereby the macroporous alumina carrier is obtained. The impregnation method is adopted to prepare the hydrodemetallization catalyst. The hydrodemetallization catalyst prepared by the method has large pore volume and pore diameter, centrally distributed pores, moderate mechanical strength and high activity and activity stability.

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.

The invention discloses a hydrotreating guard catalyst for residual oil and application thereof. The catalyst has the advantages of large pore volume, large aperture, high porosity, rational pore distribution, larger external orifice, high pore canal penetrability and over 36 percent of 1,000nm pore canals, and is particularly applied to a hydrotreating method of a residual oil fixed bed to ensure that precipitated metals are uniformly deposited on the whole catalyst bed and impurities, namely vanadium and calcium, can be deposited inside the pore canals so as to improve the utilization ratio of pores and maintain long-period running.

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 current landscape for preparative chromatographic RNA purification uses reversed phase HPLC, but this technique presents many issues with process scale up and ion exchange for preparative purification has only been used for short RNAs. The invention provides preparative purification of RNA (e.g., mRNA) using ion (e.g., anion) exchange chromatography that allows for separation of longer RNAs up to 10,000 nucleotides in length via a scalable method. This method avoids problems with current techniques by using low pressure chromatography that is agreeable with existing equipment in cGMP commercial facilities, that uses aqueous-bases solutions as the mobile phase (rather than flammable of greater than 10 mg RNA/mL resin (e.g., using larger pore sorbents, >500 Angstroms, that display greater mRNA binding capacities), and that yields desired RNA salt forms for downstream formulation with no additional manipulation necessary (unlike ion pair reverse phase techniques).

A process for converting undesirable olefinic hydrocarbon streams to hydrogen and petrochemical feedstock e.g. light olefins in C2-C4 range and aromatics especially toluene and xylenes, which comprises simultaneous cracking and reforming at olefin rich hydrocarbons using a catalyst consisting of dehydrogenating metal components, shape selective zeolite components and large pore acidic components in different proportions in a circulating fluidized bed reactor-regenerator system having reactor temperature within 450-750 DEG C. and WHSV of 0.1-60 hour-1.

The present invention provides porous mineral oxide beads which have large pore volumes and enhanced stability. The beads are based on a tetravalent metal oxide, such as zirconia, titania or hafnia. These highly porous beads are produced from a mixture of tetravalent mineral oxides, mineral pore inducing agents which are oxides or salts of trivalent metals, and optional binders. The porous mineral beads can be filled with a polymer gel and used for adsorption and chromatography applications.

The catalytic cracking catalyst contains medium and large pore alumina with average pore size not smaller than 3 nm 5-60 wt%, zeolite 5-60 wt%, adhesive 5-40 wt% and clay 5-85 wt%. The preparation process includes mixing the said materials, spraying, roasting, washing and drying. Compared with conventional catalyst, the catalyst has strengthened heavy oil converting capacity, obviously improved gasoline and coke selectivity and strengthened heavy metal nickel resistance.

The invention provides a method for preparing a multilevel porous carbon base composite phase change material, and belongs to the field of composite phase change materials. The method comprises the following steps: at first, preparing an organic metal skeleton material by using such methods as a solution method, a solvothermal method or a stirring synthesis method; with the organic metal skeleton material as a template, high temperature carbonizing under the protection of an inert gas, and changing the carbonizing temperature and the post treatment manner to obtain a multilevel porous carbon material with a super-large specific surface area and a super-large pore volume; selecting proper solvents according to different kinds of phase change core materials, preparing the phase change core materials to a solution, dispersing the porous carbon material into the solution, removing the solvent by such manners as heating, and meanwhile the phase change core materials are adsorbed and limited in the porous carbon material. The composite phase change material prepared by the method provided by the invention has good thermal storage property, can effectively avoid the leakage problem of the phase change core material, and has the advantages of excellent heat transfer property, good cycling stability and wide application range, and the process is simple and is suitable for large-scale production.

The invention relates to a calibration method for representing dense sandstone pore size distribution by adopting nuclear magnetic resonance; the method comprises the steps of measuring the rock porosity and the skeleton density; carrying out a low-temperature broken sample N2 absorption and desorption experiment, and carrying out a nuclear magnetic resonance test and a high pressure Hg injection test on a regular column sample in a saturated formation water state; converting pore volume obtained through N2 absorption into porosity components under different pore throat radiuses by using a capillary accumulated Hg inlet curve, and establishing a pore proportion summation curve by synthesizing low temperature N2-high pressure Hg injection; determining a best calibration coefficient by comparing the nuclear magnetic resonance pore proportion summation curves under the different C values to realize the conversion between nuclear magnetic resonance T2 spectrum and the pore throat radius; establishing a relation between parameters of the calibration coefficient C and a reflection pore-throat structure according to lithological characters; carrying out nuclear magnetic resonance conversion on dense sandstone reservoirs which are positioned in the same region and have the same lithological character. According to the method, the nuclear magnetic resonance T2 spectrum is calibrated by combining low temperature N2 absorption and a high pressure Hg injection experiment, and large pores, micropores and mesopores are calibrated, so that the distribution of different grades of pore sizes in dense sandstone can be effectively represented.

The invention discloses a bulk phase catalyst and a preparation method thereof. The bulk phase catalyst is prepared from an inorganic oxide precursor, a hydroxide gel and an active metal hydroxide gel serving as raw materials by molding and roasting. In the preparation process of the bulk phase catalyst, because the hydroxide gel contains a surfactant and hydrocarbon components, after the hydroxide gel is molded and roasted, the nano oxide particles formed by dehydrating the polymerized hydroxide also have a rod-shaped basic structure and pile up into a framework structure in an unordered mode. Therefore, the catalyst has the advantages of large pore volume, large pore diameter, high porosity, large orifices on the outer surface, good pore penetrability, and contribution to increasing the impurity deposition and prolonging the operation period of the catalyst.

The invention discloses a heavy oil hydrotreating catalyst and a preparation method thereof. The method for preparing the catalyst adopts a complete mixed kneading method; a carrier material comprises pseudo-boehmite glue powder and alumina powder; and an active metallic solution contains nonionic surfactant. The catalyst prepared by the method has the characteristics of large pore volume and pore diameter, proper specific surface area, even active metal dispersion and the like, and can be used in the processes of heavy oil hydrodemetalization, hydrodesulfurization and the like.

The invention relates to a prosthesis that can be implanted in the centre of wall wound scarring. The inventive prosthesis, which is intended for use in abdominal surgery, is provided with a geometric shape in the form of sheets that converge in dihedral angles. The sheets or planes are made from a synthetic biotolerated material in porous form with large pores. One of said planes is inserted into the centre of the scarring between the two aponeurotic surfaces to be joined. The other plane(s) of the prosthesis, which is perpendicular to the aforementioned plane, is arranged so as to overlap the aponeurotic edges of the edge of the section. The proliferation obtained around the prosthesis, in the scarring centre and close thereto, provides stress resistance greater than that obtained in standard closures, thereby greatly reducing the risk of hernias caused by a badly healed wound.

A separator includes a non-woven fabric substrate having pores, fine thermoplastic powder located inside the pores of the non-woven fabric substrate, and a porous coating layer disposed on at least one surface of the non-woven fabric substrate. The fine thermoplastic powder has an average diameter smaller than that of the pores and a melting point lower than the melting or decomposition point of the non-woven fabric substrate. The porous coating layer includes a mixture of inorganic particles and a binder polymer whose melting point is higher than the melting or decomposition point of the fine thermoplastic powder. In the porous coating layer, the inorganic particles are fixedly connected to each other by the binder polymer and the pores are formed by interstitial volumes between the inorganic particles. Previous filling of the large pores of the non-woven fabric substrate with the fine thermoplastic powder makes the porous coating layer uniform.

The present invention relates to hybrid wicking materials for use in high performance heat pipes and other fields where a bi-modal distribution of pore sizes offers advantages over a homogeneous monolithic porous structure. In one aspect, the invention provides a wicking material for use in heat pipes. This wick is comprised of sintered metal powder formed on a foam, felt, screen or mesh metal substrate. A fine pore structure is formed by the metal powder while the substrate is comprised of large pores. The large pores are several times, preferably five times to several orders of magnitude larger in size than the small pores. The sintered powder metal and the metal substrate may be made of nickel, copper, molybdenum, niobium, aluminium, iron, cobalt, titanium and alloys based on these metals, and combinations thereof. In another aspect, the invention provides a wicking material for use in heat pipes comprised of a hybrid wick structure with axial and radial variations in pore size for optimized performance under both horizontal and against gravity orientations.

A porous concrete road surface structure made from polymer modified cement and a construction method thereof are disclosed. The structure successively comprises a bottom layer, a bonding layer, a porous concrete layer and a surface treatment layer. The bonding layer is located on the bottom layer, and the porous concrete layer on the bonding layer is prepared through paving, leveling and jolting a composition mixed from broken stone, sand and a slurry mixture of polymer modified cement. The addition of polymer promotes bonding of granular materials with the slurry mixture tightly, the use of the bonding layer makes the road surface structure and the bottom layer form an integral body, and the road surface structure has high strength, good crack resistance, water resistance, ageing resistance and corrosion resistance; the use of an intermittent or single graded of particles results in large pores, makes the road surface water-penetrating, decreases noise and amount of the polymer; and, the surface treatment can improve markedly surface properties and its use according to the application can make the porous concrete layer has rigid or flexible characteristic. The porous concrete road surface can be paved, leveled and jolted by paving machine or manual labor.

A blood testing tool is provided, which separates blood cells and can collect blood plasma or blood serum with a high yield. The blood testing tool includes an asymmetric porous membrane with a pore size distribution in which an average pore size varies to be reduced continuously or discontinuously in a thickness direction. The porous membrane includes a blood supply portion, a development portion, and a blood-cell blocking portion formed between the blood supply portion and the development portion and pores in the blood cell blocking portion include only pores through which blood cells cannot pass. When blood is supplied to one side with larger pores of the blood supply portion, the blood moves in a direction parallel to a surface of the porous membrane by a capillary phenomenon, but only blood plasma or blood serum moves into the development portion to develop.