39results about How to "Reduce internal diffusion resistance" patented technology

A catalyst for aromatizing paraffin is a non-noble metal modified nano-class zeolite molecular sieve, which is composed of MFI-type zeolite molecular sieve as carrier and the Zn and Ga as active component. It has high catalytic activity, selectivity and stability. Its preparing process is also disclosed.

The invention researches a loaded molybdenum nitride catalyst and a preparation method thereof. The preparation method comprises the following steps: with mesoporous carbon (MC) as a carrier, loading an active component onto the carrier according to an equivalent-volume impregnation method, drying to obtain a catalyst precursor, and carbonizing and then nitriding the obtained precursor to obtain the loaded molybdenum nitride catalyst. The loaded molybdenum nitride catalyst prepared by the preparation method has relatively high activity during a hydrodeoxygenation reaction of guaiacol and has relatively high benzene selectivity.

The invention relates to an application of a hydrogenation catalyst to preparation of 1,4-cyclohexanediamine. A method for preparing the 1,4-cyclohexanediamine comprises the following steps of: adding a ruthenium catalyst consisting of an active ingredient and a carrier into a stainless steel high-pressure reaction kettle with a stirring function; adding para-phenylene diamine; adding a solvent and an aid; closing the reaction kettle; replacing air in the reaction kettle with nitrogen for at least three times; replacing nitrogen in the reaction kettle with hydrogen for at least three times; charging hydrogen till a reaction pressure in the reaction kettle is 1-10 MPa; heating the reaction kettle till a reaction pressure is 80-180 DEG C; and performing catalytic hydrogenation to prepare the 1,4-cyclohexanediamine. In the method for preparing the 1,4-cyclohexanediamine by performing catalytic hydrogenation with the para-phenylene diamine, a hydrogenation reaction technology for using the stainless high-pressure reaction kettle with the stirring function is adopted, and a catalyst carrier is pretreated, so that the activity of the catalyst is raised, the consumption of the catalyst is lowered, and catalyst cost is reduced greatly; and process conditions are optimized, so that high transformation ratio of the para-phenylene diamine is kept, and the high selectivity of the 1,4-cyclohexanediamine serving as a product is raised.

The invention relates to a Pt-load catalyst taking mesoporous carbon as a carrier, which is characterized in that the mesoporous carbon is pretreated before Pt is loaded; the pretreatment method comprises one in the following steps of: (1) adding the mesoporous carbon into a 10-30% hydrogen dioxide solution, soaking for 1-24hours, washing and removing hydrogen peroxide; (2) adding the mesoporous carbon into a 1-6M hydrochloric acid or nitric acid solution, soaking for 1-24hours, washing and removing hydrochloric acid or nitric acid; and (3) adding the mesoporous carbon into a 1-6M sodium hydroxide solution, soaking for 1-24hours, washing and removing alkali, wherein the load quantity of Pt is 0.5-5%. The invention also relates to the application of the Pt-load catalyst in preparation of 2, 2'-dichloro hydroazobenzene (DHB) from ortho-nitrochlorobenzene through hydrogenation. The catalyst uses the mesoporous carbon as the carrier, so that the internal diffusion resistance can be better reduced, and the reaction speed is accelerated. The Pt-load catalyst is high in reaction activity and selectivity, and can be repeatedly used for more than eight times, so that the using cost of the catalyst is lowered.

The invention relates to an iron-based catalyst for preparing low-carbon alkane as well as a preparation method and a using method of the iron-based catalyst for preparing the low-carbon alkane. The iron-based catalyst for preparing the low-carbon alkane is mainly used for solving the problems that the reaction of preparing low-carbon alkane from a synthesis gas in the prior art is low in CO conversion rate and low in low-carbon alkane selectivity, and the catalyst is poor in strength and thermal stability under a using condition. The problems are solved very well by adopting a technical scheme that the catalyst comprises the following components in parts by weight: a) 20-80 parts of an iron element or oxides thereof; b) 1-15 parts of a cobalt element and oxides thereof; c) 10-30 parts of at least one element selected from molybdenum and vanadium or oxides thereof; d) 5-20 parts of at least one element selected from magnesium and barium or oxides thereof; e) 5-20 parts of at least one element selected from tin and aluminum or oxides thereof; and f) 0.5-10 parts of a scandium element or oxides thereof. The catalyst can be used for industrial production of preparing low-carbon alkane from the synthesis gas by virtue of a one-step process.

Disclosed are a method for preparing an MFI catalyst carrying transition elements and MFI catalyst application. Cationic gemini surfactant- dibromide-1-(dimethyl hexyl ammonium)-6-(dimethyl octodecyl ammonium) hexane is used as structure directing agent of the MFI catalyst, sodium silicate is used as a silicon source and is subjected to low-temperature hot crystallization under self-generated pressure in a rotationally dynamic manner, and after directional polycondensation, rearrangement, nucleation and growth of inorganic atom Si-Al-Na-O on a two-dimensional plane, and single-structure-cell nano-layer MFI catalytic materials which are in mesoporous and microporous structure with the thickness ranging from 2 nanometers to 5 nanometers only are synthetized. Activity center point number of the MFI catalyst is increased evidently by utilizing two-dimensional single-structure-cell nano MFI carrying transition elements of Fe and Mo, the thickness of the catalyst crystal is reduced effectively, diffusion path is shortened, and molecular diffusion is speeded up. In addition, according to the result of a test of utilizing the selective catalytic reduction (SCR) process to remove tail gas of automobiles, NOx removal rate reaches 99.5%.

The invention discloses a heterogeneous ultraviolet-Fenton oxidation catalyst and preparation and application thereof. Prussian blue is used as iron sources, the Prussian blue is deposited on an amino-functional SiO2 mesoporous film with vertical hole passages in an automatic assembly manner, the Prussian blue is fixed through the physical absorption and the interaction force between the positive and negative charges, the bonding is firm, and the loosing is avoided; the prepared catalyst is the film catalyst, the specific surface area is large, the utilization efficiency of active components is high, the catalytic efficiency is high, and compared with the powdery and granular catalysts, the separation and the recovery are easy. Because the catalyst is provided with the mesoporous passages which are vertically distributed, the internal diffusion resistance is little, and many organic matters are suitable for being treated; at the same time, the Prussian blue loaded by the catalyst contains various states of iron, so that the Prussian blue has a cooperating function; in addition, the preparation method disclosed by the invention is simple in technology and wild in condition, so that the preparation method is suitable for popularization and application.

The invention discloses a monolithic cluster alumina supported catalyst and an application thereof. A supporter contains a hierarchical-structure alumina coating and a monolithic porous ceramic matrix, wherein the hierarchical-structure alumina coating is a micron-sized cluster substance formed by laminating blades with nano-thickness and is of a flower-like structure.

The invention discloses a rapid sanitary appliance production method which includes the steps: grouting and forming: pouring slurry into a mold, demolding to form a sanitary appliance mud blank; microwave drying: conveying the sanitary appliance mud blank into a microwave drying oven to dry the mud blank for 3-6 hours. Microwave drying stages sequentially include a slow drying stage, an accelerated drying stage, a rapid drying stage and a cooling stage. The sanitary appliance mud blank is dried by the aid of a microwave drying mode, a drying period is controlled within the range from 3 hours to 6 hours and reduced to a large extent, and the production efficiency is improved. The method adopts four microwave drying stages, so that the sanitary appliance mud blank is slowly dried, dried in an accelerated manner, rapidly dried and cooled, and the drying qualification rate of sanitary appliances is effectively increased and reaches 97%.

The invention provides a preparation method of a sheet ZSM-5 molecular sieve. The method includes: in a gel preparation process, mixing a silicon source, an aluminum source, a template agent and an additive, and performing stirring at 10-50DEG C for 1-20h; conducting standing aging for 10-30h at 10-90DEG C; putting the prepared gel reaction mixture into a reaction kettle, then putting the reactionkettle into an oven, conducting crystallization at 100-220DEG C for 4-30h, then taking the product out, and carrying out filtering, washing and drying to obtain the ZSM-5 molecular sieve product. Themethod provided by the invention synthesizes the ZSM-5 molecular sieve under a solid like phase condition, and the obtained ZSM-5 molecular sieve product is sheet shaped, and has a relative crystallinity of 90-110%, and an SiO2/Al2O3 molar ratio of less than or equal to 100.

The invention discloses a method for ozonizing organic matters in wastewater by using an activated carbon structured catalyst, and belongs to the technical field of sewage purification. The catalyst is composed of a carrier, an active component and an auxiliary agent, the carrier is honeycomb activated carbon, the active component is one or more of Mn, Fe, Co, Ni, Cu, Zn, Y and Zr, and the auxiliary agent is one or more of La and Ce. The preparation method comprises the following steps: (1) washing and drying the carrier; (2) preparing an impregnation liquid containing the active component andthe auxiliary agent; (3) placing the carrier in the impregnation liquid for impregnation to obtain a catalyst precursor; and (4) washing, drying and calcining the catalyst precursor to obtain the activated carbon structured catalyst. The catalyst is applied to treatment of organic wastewater, has the characteristics of small bed pressure drop, uniform gas distribution, small internal diffusion resistance, high COD removal rate and the like, and has a good application prospect.

The present invention relates to a high-temperature sintering type sulfur-containing iron-based catalyst and a preparation method thereof. A purpose of the present invention is to mainly solve the problems of low CO conversion rate and low low-carbon olefin selectivity in the low-carbon olefin preparation reaction with synthesis gas, and poor strength and poor thermal stability of the catalyst under the use condition in the prior art. The catalyst comprises, by weight, a) 5-50 parts of iron or an oxide thereof; b) 1-15 parts of ruthenium or an oxide thereof; c) 10-30 parts of calcium or an oxide thereof; d) 10-30 parts of at least one element selected from vanadium and chromium, or an oxide thereof; e) 10-75 parts of aluminum or an oxide thereof; and f) added trace amount calcium sulfate, wherein the catalyst contains 20-200 ppm sulfur based on the total weight of the iron-based catalyst. With the technical scheme, the problems in the prior art are well solved. The catalyst of the present invention can be used for the low-carbon olefin preparation with synthesis gas in industrial production.

The present invention discloses a hetero-type methanation catalyst and a molding process and application thereof. The process is as follows: nickel-based synthesis gas methanation catalyst powder is prepared into porous cylinder particles by compression or squeezing, wherein diameter Phi of a profile circumscribed circle of the porous cylinder particles is 3-22mm, height is 3-12mm, ratio of surface area / grain skeleton volume is 0.8-1. 6mm<2> / mm<3>, the maximum radial mass transfer distance is 1.4-4.0mm, and the geometric shape of the porous cylinder particles is regular and symmetrical. The molding process of the hetero-type methanation catalyst aims at process characteristics and requirements of various stages of the synthesis gas methanation process, the utilization efficiency of catalyst active components can be improved, and the hetero-type methanation catalyst has an important role for reducing bed resistance drop and improving long-time operational stability of the catalyst.

The invention belongs to the field of preparation of a metal catalyst, and particularly relates to a nickel catalyst for hydrogenation of C5 petroleum resin and a preparation method of the nickel catalyst. The catalyst comprises a diatomaceous earth carrier treated with a reaming agent, and a catalyst Ni loaded on the carrier, wherein the reaming agent is selected from one or several kinds of sodium citrate, polyvinylpyrrolidone and polyvinyl acetate. In addition, the invention further discloses the preparation method of the catalyst. When the catalyst is used for the hydrogenation of the C5 petroleum resin, in-diffusion can be reduced, the dosage is small, the activity is high, the life is long, and water-white high-quality C5 hydrogenation petroleum resin can be prepared; and besides, the preparation technology is simple, and the catalyst is suitable for industrialized production.

The invention provides a copper/porous carbon catalyst and a preparation method and application thereof, belonging to the field of catalytic materials. According to the preparation method provided by the invention, all the components are subjected to a uniform reaction and form a stable structure in a subsequent roasting and reduction process by utilizing aging; bio-based porous carbon has a high specific surface area, and the loading capacity and dispersity of the active component copper are improved, so active sites are increased, and catalytic activity is improved; a developed pore channel and a three-dimensional communicated hierarchical pore structure are beneficial to reducing the internal diffusion resistance of reactants and products and effectively reducing CO selectivity; and meanwhile, the porous carbon contains more microcrystals, and has certain reaction activity and catalytic activity similar to crystal defects, and a large number of various functional groups on the surface of the porous carbon further improve the catalytic activity. When the catalyst is applied to hydrogen production by methanol steam reforming, the conversion rate of methanol can reach 92%, and CO selectivity is as low as 0%.

The invention belongs to the field of biological catalysis, and in particular relates to a method for preparing thymidine by immobilized Escherichia coli. The method adopts PVA and carrageenan as theembedding substrates, takes activated carbon as an additive, and immobilizes the phosphorylase-producing Escherichia coli to obtain the immobilized Escherichia coli; in the preparation of thymidine, immobilized Escherichia coli is used as a catalyst, a phosphate buffer solution is used as a solvent, 2-deoxy-alpha-D-ribose-1-dicyclohexylamine phosphate and thymine are used as a reaction substrate,and thymidine is prepared. The method adopts the immobilized Escherichia coli to prepare thymidine, and can better improve the tolerance of the bacteria to the substrate, and the stability thereof isimproved, so that the yield of thymidine is improved; The results show that after purification, the purity of thymidine is more than 97%, and the yield is more than 90%. After 6 batches of reaction, no significant loss of viability in immobilized Escherichia coli is generated.

The invention discloses a process for preparing sulfuric acid by blending and burning pyrite concentrate with ferrous sulfate. The process comprises the following steps: S1, preparing preparation equipment; s2, raw material treatment; s3, roasting is carried out; s4, a purification step; s5, carrying out dry suction; s6, carrying out conversion; and S7, preparing a finished product. According to the process for preparing sulfuric acid by blending combustion of pyrite concentrate with ferrous sulfate, the internal diffusion resistance can be reduced and the contact area between air and ore can be increased due to the small particle size of the pyrite concentrate with the particle size of 3mm, the measure is most effective for controlling the total roasting rate through oxygen diffusion, and the total roasting rate can be controlled by increasing the oxygen content of furnace entering gas; the oxygen concentration in the atmosphere is high, external diffusion and internal diffusion cone power of oxygen is large, the diffusion rate of the oxygen is high, the oxygen content in the furnace gas can be increased, catalytic conversion of So2 is facilitated, the process is simple and convenient, the cost is low, and sulfuric acid with high purity can be prepared.