7results about How to "High space-time yield" patented technology

The invention discloses a tandem catalysis method for improving the catalytic efficiency of preparing higher alcohol by CO2 hydrogenation, which comprises the following steps: two sections of fixed bed reactors are connected in series, the first section of reactor is filled with a catalyst for preparing olefin by CO2 hydrogenation, and the second section of reactor is sequentially filled with an olefin hydroformylation catalyst and a catalyst for preparing alcohol by aldehyde hydrogenation. According to the invention, segmented catalysis is carried out on the complex process of preparing higher alcohols through CO2 hydrogenation, and a catalyst for preparing olefins through CO2 hydrogenation, a hydroformylation catalyst and an aldehyde hydrogenation catalyst are respectively arranged in an upstream-segment reactor and a downstream-segment reactor, so that the efficiency and selectivity of preparing higher alcohols through CO2 hydrogenation are improved; through tandem catalysis, the selectivity of by-product hydrocarbons can be effectively reduced, the utilization rate of carbon is improved, the selectivity and space-time yield of higher alcohols are remarkably improved, and the separation cost of products is reduced.

This invention belongs to the field of polymer synthesis and microchemical technology, and discloses a method for synthesizing hydroxyl-terminated polybutadiene in a continuous flow microchannel reactor. The preparation method includes mixing butadiene, anhydrous ethanol, 30% hydrogen peroxide, and an antioxidant under nitrogen protection to obtain a raw material liquid, which is then pumped into the microchannel reactor via a high-pressure metering pump. The mixture undergoes preheating initiation and polymerization reactions sequentially, with viscosity monitored by an online viscometer. After the reaction, the product is obtained through gas-liquid separation, sedimentation and stratification, washing, vacuum solvent removal, and filtration. This invention utilizes a microchannel reactor, which provides precise temperature control and stable pressure. Segmented temperature control and online viscosity adjustment prevent reactor blockage, resulting in high product conversion and yield, and uniform molecular weight distribution. By adding auxiliary devices to optimize the process, continuous and stable production is achieved, making it more efficient, environmentally friendly, and controllable.

The invention discloses a carbon-coated iron-based catalyst as well as a preparation method and application thereof. The catalyst is carbon-coated iron trioxide loaded with alkali metal or alkali metal and nickel. In the catalyst, the loading capacity of nickel is 0-3wt%, the loading capacity of alkali metal is 0.5-5wt%, and the alkali metal is selected from at least one of Li, Na, K, Rb and Cs. The iron-based catalyst is obtained by carrying out step-by-step impregnation modification on iron trioxide through nickel salt and alkali metal salt and then introducing CO to carry out reduction carbonization treatment, the preparation method is simple, the catalyst has high activity and high target higher alcohol product space time yield on CO2 fixed bed continuous hydrogenation, the catalyst has good reaction stability and good life stability, and the catalyst is suitable for industrial production. And industrial amplification and application are facilitated.

The invention discloses a polymerization method of a polypropylene composition, and belongs to the field of polymerization. An olefin monomer comprising propylene is contacted with a catalyst system in the upstream polymerization sections of a gas phase copolymerization reactor to form polymer particles, and a condensing medium is introduced in at least one upstream polymerization section or between or after the upstream polymerization sections; in the upstream polymerization section, the obtained polymer particles and the condensing medium enter the gas phase copolymerization reactor in the form of wet particles, and in the presence of the condensing medium, propylene and alpha-olefin are polymerized in the gas phase copolymerization reactor to obtain the polypropylene composition. The condensing medium can effectively improve heat dissipation of an upstream polymerization section, enables polymer particles to be distributed more uniformly, avoids kettle sticking and caking phenomena caused by generation of local hot spots, can also improve the heat removal capability and space time yield of a gas phase copolymerization reactor, enhances the copolymerization activity of olefin monomers in the gas phase copolymerization reactor, and improves the yield of olefin monomers in the gas phase copolymerization reactor. And the bonding condition of the particle surface is improved.

The application discloses a supported metal element synergistically modified copper-based catalyst and a preparation method and application thereof. The catalyst is composed of metal copper, metal gallium, an auxiliary element M and a carrier SiO2. In the preparation method, a Cu-Ga catalyst precursor is prepared through an ammonia evaporation method, and then the auxiliary element is added through ball milling. Mechanical shearing force and impact generated in the milling process can promote sufficient contact and uniform mixing of the auxiliary element and the precursor, so that the auxiliary element is more uniformly distributed and a strong interaction is formed. Under the condition that the hydrogen ester ratio is about 200, the application can still maintain a high methyl 3-hydroxypropionate conversion rate and 1,3-propanediol selectivity.

The invention discloses a method for simultaneously preparing vinylidene fluoride and vinyl fluoride, which comprises the following step of: reacting difluoroethane under the action of a catalyst and oxidizing gas to prepare the vinylidene fluoride and the vinyl fluoride, the catalyst comprises an active component and a carrier compound, the active component comprises an active component A, or the active component comprises an active component A and an active component B; the active component A is selected from at least one of molybdenum salt, lanthanum salt, nickel salt, chromium salt, vanadium salt, platinum salt or palladium salt; the active component B is selected from at least one of sodium salt, potassium salt, cesium salt, magnesium salt or calcium salt. According to the method, difluoroethane is taken as a raw material, and vinylidene fluoride and vinyl fluoride are prepared at the same time under the action of a catalyst and oxidizing gas.

The present application proposes a polyvinyl chloride resin with high space-time yield and a preparation method thereof, and relates to the field of polymer technology. A preparation method of polyvinyl chloride resin with high space-time yield comprises the following steps: emulsifying an initiator and adjusting the concentration with a diluent before storing to obtain an initiator preparation solution; adding a pH regulator, a dispersant, deionized water and a premixed vinyl chloride monomer into a reaction container, heating and stirring to obtain a mixed solution; when the mixed solution is suspended and polymerized, adding the initiator preparation solution into the reaction container in stages; when the pressure in the reaction container begins to drop for the first time, adding vinyl chloride monomer into the reaction container, adding an antioxidant after the reaction to obtain an aqueous slurry; sending the aqueous slurry to steam stripping, centrifugal drying and homogenization treatment to obtain a polyvinyl chloride resin product with high space-time yield. The polyvinyl chloride resin prepared by this method has the advantages of high space-time yield and low water content.