36results about How to "Improve yield and selectivity" patented technology

Supported bis(phosphorus) ligands are disclosed for use in a variety of catalytic processes, including the isomerization, hydrogenation, hydroformylation, and hydrocyanation of unsaturated organic compounds. Catalysts are formed when the ligands are combined with a catalytically active metal, such as nickel.

A mixed metal oxide catalytic system consisting of molybdenum, vanadium, lanthanum and palladium providing higher yields of acetic acid in low temperature single stage oxidation of ethane with molecular oxygen-containing gas without or with reduced production of by-products such as ethylene and CO.

The invention discloses a method for synthesizing ethanol, which comprises the following steps of: 1, preparing oxalic acid diester through coupling reaction of carbon monoxide and nitrite under the catalysis of an alumina-supported palladium catalyst; 2, pre-heating and vaporizing the oxalic acid diester and mixing with hydrogen; carrying out catalytic hydrogenation reaction on the mixed gas on a silicon dioxide-supported copper catalyst, and then cooling and distilling the reaction product to obtain ethanol. The preparation method of the invention realizes over 80% of selectivity and high yield of ethanol, and the gas used in synthesis process can be completely converted through circulation, thereby establishing a good foundation for research on the industry of synthesizing ethanol frombiomass.

A mixed metal oxide catalytic system comprising MoVNbPd or MoLaVPd providing higher selectivity and space time yield of acetic acid in the low temperature single stage oxidation of ethylene with molecular oxygen-containing gas and steam with very minimum or without the production of side products such as acetaldehyde, and methods of using the same.

The invention provides an alkylation method for the combined filling of catalysts. The method comprises the following steps that raw material benzene and raw material olefin are introduced into an alkylation reactor, pass through a catalyst bed layer from top to bottom or from bottom to top, and react to form alkyl benzene under the conditions of alkylation. The alkylation reactor comprises more than two reaction zones, and more than one reaction zone is filled with more than two catalysts. Each reaction zone is filled according to the order of a catalyst A, a catalyst B and a catalyst C along the direction of feeding flow, wherein the catalyst A is a catalyst containing beta molecular sieves; the catalyst B is a catalyst containing MCM-22 molecular sieves; and the catalyst C is a catalyst containing beta molecular sieves or Y molecular sieves. The method provided by the invention allows different types of alkylation catalysts to react under respective optimized operation conditions, can give full play to the catalytic performances and synergistic effects of the catalysts, increase the selectivity and yield of mono-alkyl benzene, reduce the generation of butylbenzene and diphenylethane which are by-products, and prolong the service life of the catalysts.

The invention relates to a catalyst which is used for synthesis gas and synthetic fluid fuel, a process for preparation and use. The catalyst is composed of three parts of active components, additives and carriers, wherein the active components are iron and cobalt, the metallic iron and the cobalt account for 5%-30% of the total weight of the catalyst, the additives are zirconium and potassium, potassium additive accounts for 0.01%-15% of the total weight of the catalyst, zirconium additive accounts for 1%-20% of the total weight of the catalyst, and the others are the carriers. Compared with the prior art, the catalyst of the invention has comparatively high hydrogenation activity to CO and comparatively high selectivity and receiving rate to C5+.

A mixed metal oxide catalytic system comprising MoVNbPd or MoLaVPd providing higher selectivity and space time yield of acetic acid in the low temperature single stage oxidation of ethylene with molecular oxygen-containing gas and steam with very minimum or without the production of side products such as acetaldehyde, and methods of using the same.

The invention provides a method for resource utilization of condensed alcohol ether in epoxypropane wastewater, which comprises the following steps: treating desalted wastewater generated by an HPPO process through a modified molecular sieve catalyst to hydrolyze the condensed alcohol ether into propylene glycol and methanol so as to recover the propylene glycol and methanol from the wastewater. The method is easy for downstream biochemical treatment and improves the economical efficiency.

The invention relates to a method for producing cyclohexylamine by hydrogenating aniline in order to mainly solve the problems of low yield and low selectivity of catalytic hydrogenation of aniline tosynthesize cyclohexylamine in the prior art. The method for producing cyclohexylamine by hydrogenating aniline is characterized in that hydrogen and aniline which are used as raw materials are reacted in the presence of an aniline hydrogenation catalyst to obtain cyclohexylamine, wherein the aniline hydrogenation catalyst comprises a carrier and an active component, the carrier is phosphorus-modified Al2O3, and the active component comprises a Co element and a cocatalyst element; and the cocatalyst element comprises at least one metal element selected from alkali metals. The method well solves the problems, and can be used in the industrial production of cyclohexylamine.

The invention provides a ferrocenyl aza-annulet ligand loaded by a Frechet-type tree-like macromolecule as well as a synthetic method and an application thereof in the catalysis asymmetric ethylized reaction of all kinds of aromatic aldehyde. The ligand is prepared by linking chirality ferrocenyl tertiary alcohol to the Frechet-type macromolecule in a manner of covalent bond. The ferrocenyl aza-annulet ligand has the characteristics of simple synthetic method, and high activity and asymmetric selectivity, and is convenient to recycle; and the activity and selectivity of the catalyst are not obviously reduced after three times of recycling.

An oxidation process for the production of an aromatic carboxylic acid, said process comprising contacting in the presence of a catalyst, within a continuous flow reactor, one or more precursor(s) of the aromatic carboxylic acid with an oxidant, such contact being effected with said precursor(s) and the oxidant in an aqueous solvent comprising water under supercritical conditions or near supercritical conditions, wherein said catalyst comprises copper.

The invention provides a synthetic method for preparing a sulfo trisubstituted alkenes compound conveniently and simply. According to the method, common organic solvent serves as reaction solvent, and stable (Z)-1,2-diaryl(alkyl)sulfenyl alkene easy to obtain and an aryl(alkyl) Grignard reagent serve as raw materials and effectively react at the room temperature under catalysis of a nickel compound of the catalysis amount, so that the sulfo trisubstituted alkenes compound is obtained with high yield and high regioselectivity, and an environment-friendly way is provided for preparing the compound. The method has the main advantages that the reaction condition is mild, experiment operation is simple, and stereoselectivity and yield are high. The reaction is suitable for various (Z)-1,2-diaryl(alkyl)sulfenyl alkenes and aryl(alkyl) Grignard reagents, after the reaction mixture is oxidized by air, the main side products are diaryl(alkyl) disulphide, and the compound can continue to be used for preparing (Z)-1,2-diaryl(alkyl)sulfenyl alkenes and meet the requirement for atom economy.

Aromatic compounds are mononitrated by reaction with a nitrating agent, preferably nitric acid, in a phosphonium salt ionic liquid.

The invention provides a fluorine-containing thiocarbamate compound and a synthesizing method thereof, and belongs to the technical field of compound synthesis. The fluorine-containing thiocarbamate derivative is prepared from multiple components through a one-pot method. A chemical equivalent amount of alkali is added into a container which contains alpha-OTs substituted ketone, a substituted thiocyanate compound and a fluorine-containing alcohol compound to be stirred at the reaction temperature of 25-100 DEG C, washing is conducted with water or a saturated salt solution after reaction ends, extracting is conducted through an organic solvent, drying, depressurizing, distilling, concentrating and solvent removing are conducted, a coarse product is separated through column chromatography,and then the fluorine-containing thiocarbamate derivative is obtained. The method has the advantages that no transition metal catalysts exist, the raw materials are low in price and easy to obtain, an oligomer is wide in applicability, the reaction conditions are mild, the location selectivity is high, the yield is high, and the compound is environmentally friendly.

The invention relates to a method for synthesizing vinyl acetate. When vinyl acetate is prepared from methyl acetate through the route of carbonylation and cracking, vinyl acetate yield and selectivity are low. The invention mainly aims at solving the problems. The vinyl acetate synthesis method comprises the following steps: methyl acetate carbonylation is carried out, such that ethylene diacetate is obtained; and ethylene diacetate is cracked, such that vinyl acetate is obtained. A carbonylation catalyst adopts SiO2, Al2O3 or a mixture thereof as a carrier, and has active components comprising at least one selected from iron-series elements, alkaline earth metal and at least one metal element selected from IB and VA. With the technical scheme, the technical problem is well solved. The method can be used in industrial production of vinyl acetate.

The present invention relates to a method for increasing the selectivity of an enzyme, which method comprises performing the reaction in the presence of an enhancing compound selected from one of ethylene glycol, propylene glycol or glycerol.

The invention provides a microchannel gas-liquid reactor with a Koch curve structure. The reactor comprises at least a reactor body, an acrylic plate, a sealing ring and a stainless steel frame, the reactor body is a microchannel plate with the Koch curve structure, and the upper portion of the plate is covered with the transparent acrylic plate and pressed with the stainless steel frame. The combination of a microfluidic technology and a continuous reactor is adopted to effectively and quickly control the flow rate of raw material liquid to control residence time of reactants, thereby improving the yield and selectivity of the reaction; a 3D printing microchannel reactor is adopted, and a relatively complex microchannel structure can be accurately, rapidly and economically fabricated; a microchannel design using the Koch curve structure can effectively distribute gas-liquid two phases and enhance mass transfer.

The invention provides a novel method for catalyzing a terminal alkyne self-coupling reaction to produce a 1,3-diyne compound with a simple, highly efficient, alkali-free and reusable copper catalytic system. According to the invention, a commonly used organic solvent and water are adopted as a reaction solvent; a cheap and easy-to-obtain terminal alkyne is adopted as a raw material; and under the catalysis of a catalytic system composed of copper nitrate and Luviset Clear, a reaction is effectively carried out under a certain temperature, and the 1,3-diyne compound is prepared highly efficiently. Therefore, a green approach is provided for the preparation of the compound. The method mainly has the advantages of simple experimental operation, mild reaction conditions, and no alkali participation. The reaction is suitable for various different terminal alkynes, such that a raw material source range is wide. Copper nitrate with a low price is adopted as a reaction catalyst. With the catalyst, no other byproduct is produced, and the reaction is fast and highly efficient.

The invention provides a microchannel plate based on a cross-shaped curve, a gas-liquid reactor and reaction system and application. The microchannel plate based on the cross-shaped curve comprises areaction plate, a cross-shaped fractal structure microchannel, an input microchannel and an output microchannel, wherein the cross-shaped fractal structure microchannel, the input microchannel and theoutput microchannel are formed on one surface of the reaction plate; the input microchannel and the output microchannel are respectively connected to the two ends of the cross-shaped fractal structure microchannel to form a through reaction channel. A microfluidic technology and a continuous reactor are combined in order to effectively and rapidly control the flow of a feed solution, thereby controlling the retention time of reactants and improving the reaction yield and selectivity; the fractal structure microchannel is designed for effectively distributing gas and liquid phases, so that mass transfer is enhanced, and the efficiency is improved.

The invention relates to a method of producing vinyl acetate from methyl acetate through hydroformylation and mainly solves the problems of low yield and low selectivity of the vinyl acetate when methyl acetate is successively subjected to carbonylation and pyrolysis to prepare the vinyl acetate. The method herein includes the following steps: 1) carbonylating the methyl acetate to obtain ethylidene diacetate; and 2) pyrolyzing the ethylidene diacetate to obtain the vinyl acetate. A carbonylation catalyst includes a carrier being formed from SiO2, Al2O3 or a mixture of them, and an active component including at least one of iron-series elements, at least one element from metalloid elements, and at least one metal element selected from the groups of IIB and alkali metals. The method solves the technical problems well and can be used in industrial production of the vinyl acetate.

The invention relates to a catalyst for synthesizing ethylidene diacetate, a preparation method of the catalyst for synthesizing ethylidene diacetate and application of the catalyst in the synthesis of ethylidene diacetate. According to the catalyst, the preparation method and the application, the problems that a catalyst for synthesizing ethylidene diacetate in the prior art is relatively low in activity and selectivity are mainly solved. The catalyst comprises a carrier as well as ruthenium, chromium and alkaline earth metal which are loaded to the carrier, wherein the content of ruthenium is 3.0g / L-15.0g / L, the content of chromium is 1.0g / L-5.0g / L, and the content of alkaline earth metal 0.5g / L-5.0g / L; the carrier is selected from at least one of silicon oxide and aluminum oxide. According to the technical scheme, the technical problems are well solved. The catalyst can be applied to the industrial production of vinyl acetate.

The invention relates to a catalyst for synthesizing ethylidene diacetate and a preparation method of the catalyst for synthesizing ethylidene diacetate. According to the catalyst and the preparation method, the problems that an ethylidene diacetate catalyst is relatively low in activity and selectivity in the prior art are mainly solved. The catalyst comprises a carrier as well as nickel, molybdenum and tin which are loaded to the carrier, wherein the content of nickel is 3.0g / L-15.0g / L, the content of molybdenum is 1.0g / L-5.0g / L, and the content of tin is 0.5g / L-5.0g / L; the carrier is selected from at least one of silicon oxide and aluminum oxide. According to the technical scheme, the technical problems are well solved. The catalyst can be applied to the industrial production of vinyl acetate.

The invention relates to catalyst for preparation of 3-acetoxy propionaldehyde, and mainly solves the problems of low activity and selectivity of 3-acetoxy propionaldehyde catalyst in the prior art. According to a technical scheme, the catalyst adopts SiO2, Al2O3 or a mixture thereof as the carrier, the active component includes at least one of iron series elements, an alkaline earth metal element and at least one metal element selected from IVA and IIB, thus welling solving the problems. The catalyst provided by the invention can be used for the industrial production of 1.3-propanediol.

The invention discloses an electrochemical preparation method of p-aminophenyl-beta-hydroxyethyl sulfone. The method comprises the following steps: using an electrolytic cell as a reactor, separatinga cathode chamber and an anode chamber by using a cationic diaphragm, respectively adding a sulfuric acid solution into the cathode chamber and the anode chamber, keeping the distance between electrode plates constant, adding p-nitrophenyl beta hydroxyethyl sulfone serving as a raw material into the cathode chamber, controlling the reaction temperature to be constant, performing electrifying for electrolysis, keeping the current density constant in the reaction process, and stopping electrifying when the introduced electric quantity reaches the target electric quantity so as to obtain an electrolyte containing p-aminophenyl beta hydroxyethyl sulfone sulfate; and neutralizing the catholyte with sodium hydroxide until the catholyte is alkaline, carrying out rotary evaporation to remove waterto obtain a solid, dissolving the solid with methanol, performing filtering to remove insoluble solids, and carrying out rotary evaporation on the filtrate to remove methanol to obtain a solid p-aminophenyl beta hydroxyethyl sulfone. The method provided by the invention is high in selectivity and yield, and the yield reaches 100% after sufficient electric quantity is introduced.

The invention discloses a polysubstituted 1,2,4-oxadiazole-5-imine derivative and a synthesis method thereof, and belongs to the field of organic matter synthesis, wherein the method comprises the steps: adding a solvent into a container loaded with substituted nitrone and a substituted carbodiimide compound, stirring at the reaction temperature of 25 DEG C-100 DEG C, washing with water or a saturated salt solution after the reaction is finished, then extracting with an organic solvent, drying, carrying out reduced pressure distillation and concentration to remove the solvent, and carrying outcolumn chromatography separation on the crude product to obtain the target product 1,2,4-oxadiazole-5-imine compound. The method has the advantages of no transition metal catalyst, cheap and accessible raw materials, wide reaction substrate adaptability, mild reaction conditions, favorable regioselectivity, high yield, environment friendliness and the like, and has favorable industrial application prospects.

The ordered mesoporous copper-rare earth metal-aluminum composite oxide catalyst disclosed by the invention has a highly ordered mesoporous structure and a relatively high specific surface area, and the copper and rare earth metal oxide and the aluminum oxide carrier are tightly interacted and are highly uniformly dispersed. The highly dispersed Cu active component provides a large amount of ethanol dehydrogenation activity or crotonaldehyde hydrogenation centers, and the highly dispersed rare earth metal oxide and the alumina carrier provide a large amount of acid-base active centers for promoting acetaldehyde aldol condensation, so that efficient conversion from ethanol to higher alcohol is finally realized. And meanwhile, the sintering and growth of the oxides of the Cu and the rare earth metals are limited by mutual doping and strong interaction among the oxides of the Cu, the rare earth metals and the aluminum, so that the catalyst shows excellent stability in 500-hour long-time evaluation.

The invention discloses a carborane supported salen ligand, a nested carborane supported salen-Al catalyst as well as preparation and application of the nested carborane supported salen ligand and the nested carborane supported salen-Al catalyst. The molecular structural formula of the carborane-supported salen ligand is shown in a formula I, and the molecular structural formula of the nested carborane-supported salen-Al complex is shown in a formula II. The preparation method comprises the following steps: reacting diamino-o-carborane with salicylaldehyde to obtain a salen ligand containing o-carborane; and then reacting with triethyl aluminum, so as to obtain the salen-Al complex containing the nested carborane. The method is simple in synthesis process and has good selectivity and yield.

The invention provides a method for efficiently preparing polysubstituted pyrazole derivatives in a water phase, and belongs to the technical field of organic synthesis. The method comprises the following steps: adding a proper amount of water, a small amount of solvent and a proper amount of alkali into a container filled with a substituted 2-methylene benzofuranone derivative and a toluenesulfonyl diazomethane derivative, stirring at a proper reaction temperature, filtering after the reaction is finished, adding water or a saturated salt aqueous solution into the filtrate, extracting with an organic solvent, and drying to obtain the substituted 2-methylene benzofuranone derivative. And carrying out reduced pressure distillation and concentration to remove the solvent, and carrying out column chromatography separation on the crude product to obtain the target product polysubstituted pyrazole derivative. The method has the advantages of efficient reaction, environmental protection, convenience, rapidness, wide substrate adaptability, high yield and the like, and has a good industrial application prospect.

The invention relates to a catalyst for producing ethylidene diacetate. The catalyst is mainly used for solving the problem in the prior art that catalysts for ethylidene diacetate are relatively low in activity and selectivity. Through adopting the technical scheme that the catalyst for ethylidene diacetate adopts SiO2, Al2O3 or a mixture of SiO2 and Al2O3 as a carrier, and active ingredients comprise at least one element selected from platinum family metals, at least one element selected from metalloid elements and at least one metal element selected from IIB and lanthanide series metal elements, the technical problem is better solved, and the catalyst can be applied to the industrial production of vinyl acetate.