36results about How to "Avoid deep oxidation" patented technology

The invention discloses a CeO2-ZrO2 based SCR (selective catalytic reduction) catalyst used for denitration and a preparation thereof and belongs to the field of nitric oxide post-processing purification. The catalyst has a three-layer structure, wherein cordierite honeycomb ceramic is used as a carrier; an active coating is loaded on the carrier; a modifying coating is loaded on the active coating; the cordierite carrier has a skeleton carrying function; the active coating of the catalyst mainly has a function of activating NOx and NH3; and the modifying coating mainly has functions of storing NH3, avoiding deep oxidation of NH3 on the surface of the catalyst when the catalyst is used at a high temperature and increasing the sulfur poisoning resistance of the catalyst. The preparation process of the catalyst is simple and can be easily industrialized. A working temperature window of the optimized catalyst can reach 250-450 DEG C, and denitration efficiency is above 80%. The catalyst has the significant advantage of being nontoxic and has excellent heat stability and excellent SO2 poisoning resisting property.

The invention discloses a mesoporous carbon-supported composite metal oxide catalyst and a preparation method thereof. Compared with the prior art, the mesoporous carbon-supported composite metal oxide catalyst has a high specific surface area and a large aperture size, is conducive to rapid diffusion of reactants and products in an aperture channel, avoids deep oxidation, coking and carbon deposition, and has good catalyst activity and a long catalyst life.

The invention relates to a catalyst for preparing phenol by hydroxylation of benzene and a preparation method thereof. The component expression of the catalyst provided by the invention is Cs2.5(MIMPS)nH1.5-nPMo11VO40, wherein MIMPS indicates [N-(3-sulfonic)propyl-imidazolium] and n equals to 0.5-1.5. The preparation method provided by the invention comprises the following steps of: (1) preparingpure vanadium substituted heteropolymolybdates; (2) mixing the pure vanadium substituted heteropolymolybdates obtained from the step (1) with deionized water, adding dropwisely an inorganic cesium salt solution into the above solution with stirring, followed by a reaction, removing water from a suspending liquid obtained after the reaction so as to obtain a solid, drying to obtain a heteropolyacid inorganic cesium salt; (3) mixing the heteropolyacid inorganic cesium salt obtained from the step (2) with deionized water, adding dropwisely an MIMPS aqueous solution with stirring, followed by a reaction, removing the solvent from a suspending liquid obtained after the reaction so as to obtain a solid, and drying to obtain the catalyst for preparing phenol by hydroxylation of benzene. By the adoption of the catalyst provided by the invention, the yield of phenol can be obviously raised; in addition, the catalyst is easy to recover and convenient to repeatedly use.

The invention relates to a method for preparing styrene through oxidative dehydrogenation of ethylbenzene and aims at solving the problem that the selectivity is poor when styrene is prepared through oxidative dehydrogenation of the ethylbenzene at an oxygen gas atmosphere in the prior art. According to the technical scheme, the method for preparing the styrene through oxidative dehydrogenation of the ethylbenzene comprises the following step: by taking a carbon nonmaterial as a catalyst, nitrous oxide as an oxidant and gas which is inert to reaction as a diluent, preparing the styrene through oxidative dehydrogenation of the ethylbenzene, so that the method relatively well solves the technical problems and can be used for industrial production of the styrene.

A green synthesis of phenol by benzene hydroxylation directly is carried out by apply DC high-voltage 10-30 kV onto plasma reactor to generate corona, discharging, keeping temperature of plasma reactor between 50-80 deg. C, inducing into raw material containing benzene and oxidant into reactor in proportion of 1:1-6 mol, keeping for 5-10 mins and oxidizing into phenol. It's simple and convenient, has short flow path, less consumption, more yield and no environmental pollution.

The invention discloses a nitric acid loop oxidation device and selective oxidation of dimethyl nitrobenzene in the device. The device is characterized in that the device (as shown in the attached drawings of the specification) consists of 1, a reaction kettle 2, a condenser 3, a pressure relief valve 4, a circulation pipeline 5, an air or oxygen steel cylinder or storage tank 6, a circulation pump 7, a filter pressing tank 8, a spray head 9, a valve III 10, a controller 11, a valve I 12, a valve II 13 and a pressure reducing valve. The selective oxidation of dimethylnitrobenzene is carried out in the device, and the result shows that the device can selectively oxidize the nitromonomethylbenzoic acid generated by dimethylnitrobenzene with high yield and high selectivity. At the same time,nitric acid is recycled by using the principle that oxygen reacts with nitrogen oxides and water to generate nitric acid, the emission of nitrogen oxides is greatly reduced, the total pressure of thereaction system is reduced, and the safety is improved.

The invention provides a synthetic method of p-tert-butylbenzaldehyde. A liquid-phase oxidation method is used, p-tert-butyltoluene as a raw material, oxygen as an oxidizing agent, N-hydroxyl phthalimide as an initiator and acetonitrile as a solvent are used under the action of a catalyst for reacting for 7 hours at the temperature of 70 DEG c under the magnetic stirring rotating speed of 200r/minso as to obtain the p-tert-butylbenzaldehyde. The selected catalyst is a Ni-loaded microporous molecular sieve, and preparation raw materials comprise a nickel salt, a molecular sieve and deionized water; the microporous molecular sieve is used as a carrier for loading of an active component by an impregnation method to prepare the catalyst containing the active component nickel, the catalyst hasrelatively high selectivity and activity, the conversion rate of the raw material in the reaction for preparing the p-tert-butylbenzaldehyde by the liquid-phase oxidation reaches 30.6%, the selectivity of the target product reaches 77.2%. Compared with other catalysts in the prior art, the catalyst has the advantages that the selectivity is obviously improved.

The invention relates to the technical field of catalysts, and provides an organic contaminated soil thermal desorption waste gas catalytic oxidation purification catalyst and a preparation method and application thereof. The catalyst provided by the invention comprises a matrix, a carrier and active components, the matrix is honeycomb cordierite, the carrier is a CeO2-ZrO2 compound or a CeO2-ZrO2-R compound (R is one or more of La2O3, Co3O4, Y2O3 and SiO2), the active components are MnO2 and RuO2, and an auxiliary agent WO3-TiO2 is further loaded on the matrix. The catalyst provided by the invention has high catalytic efficiency in a temperature range of 450-650 DEG C, can completely convert organic contaminated soil thermal desorption waste gas, has good high-temperature stability, strong sintering resistance and carbon deposition resistance, and also has good alkali, alkaline earth and heavy metal resistance, chlorine resistance and sulfur poisoning resistance.

The invention belongs to the technical field of inorganic membrane reactors and in particular relates to a preparation method of an oxygen-permeation-hydrogen permeation-methane partial oxidative dehydrogenation three-effect flat plate type membrane reactor and a testing system thereof. The preparation method comprises the following steps: preparing a dense ceramic oxygen-permeation membrane, a dense ceramic hydrogen-permeation membrane and a nickel catalyst, and laying the nickel catalyst on the surface of the hydrogen-permeation membrane; putting an alundum tube for sealing the oxygen-permeation membrane into an alundum tube for sealing the hydrogen-permeation membrane to form a core component, further putting the core component into a quartz tube, and finally connecting a sealing cap with a gas channel with the quartz tube, thereby obtaining the reactor. By adopting the reactor, continuous controllable oxygen supply can be achieved, and deep oxidation of methane can be prevented; in-time separation of hydrogen from carbon monoxide can also be achieved, and reaction balance can be promoted to move towards a product direction. By adopting the preparation method, problems that rawmaterials of partial methanol oxidation reactions are separated and methane reactions and product separation cannot be carried out in a same reactor simultaneously can be solved.

The invention discloses a catalyst for preparing maleic anhydride by oxidizing n-butane as well as a preparation method and application of the catalyst. The catalyst comprises a catalyst substrate and an inert carrier, the catalyst substrate comprises vanadium phosphorus oxide, and the inert carrier is an inert heat conduction material. The inert carrier is selected from at least one of silicon nitride, aluminum nitride and boron nitride. The preparation method comprises the following steps: uniformly mixing the inert carrier and the catalyst matrix powder, carrying out compression molding, crushing, adding the pore-forming agent, repeating the molding and crushing processes for 2-10 times, molding, and carrying out heat treatment to obtain the catalyst. By adopting the inert carrier, hot spots of the reaction can be diluted, a local specific inert region can be formed, heat in the oxidation reaction process can be transferred, deep oxidation of maleic anhydride is avoided, and the selectivity of the catalyst is improved.

The tubular catalytic membrane reactor comprises external tube and internal tube, between external tube and internal tube there is a gap through which air stream can be easily passed. The internal tube s made up by welding imporous metal tube onto both ends of microporous metal tube respectively, and the micropore size of the microporous metal tube is micrometer level, and the external urface of microporous metal tube is coated with catalytic membrane layer. Said invention adopts metal tube as support body, and adopts membrane type catalyst, so that it improves heat-transferring condition, and is favourable for accelerating reaction speed and raising yield of product.

The invention provides a multi-channel riser reaction device and application thereof. The reaction device comprises at least three riser reactors, a sedimentation device, a gas-solid separation device and a material returning device, wherein the riser reactors are arranged in parallel, and heat transfer is performed between the adjacent riser reactors; the upper part of the riser reactor is connected with the bottom of the sedimentation device, and a discharge hole of the riser reactor is higher than a discharge hole in the bottom of the sedimentation device; the bottom of the riser reactor is connected with a discharge hole of the material returning device; and a feed gas inlet pipeline is arranged at the bottom of the riser reactor. The at least three riser reactors are connected in parallel so as to be suitable for the cascade reaction with strong heat absorption/heat release characteristics, and through the gap heat transfer of each riser reactor, the bed temperature of the riser reaction zone is uniform, such that the isothermal reaction process is easily achieved, and the selectivity of the target product is further improved.

The invention provides a fluidized bed reaction device and application thereof. The fluidized bed reaction device comprises a fluidized bed reactor, the top of the fluidized bed reactor is provided with a catalyst inlet and a product gas outlet, and the bottom of the fluidized bed reactor is provided with a catalyst outlet and a feed gas inlet. In the axial direction, at least two layers of fluidized beds are arranged in the fluidized bed reactor. A pore plate is arranged at the bottom of each layer of fluidized bed. An overflow pipe is arranged between every two adjacent layers of fluidized beds. The structure of the fluidized bed reaction device is improved, so that gas back-mixing is reduced, the fluidized state is effectively stabilized, and unstable product composition caused by an unstable fluidized bed state is avoided. The fluidized bed reaction device is applied to a methane oxidative coupling reaction, oxygen enters the fluidized bed reactor in a graded mode, deep oxidation of methane is avoided, and C2 + selectivity is improved on the premise that the methane conversion rate is guaranteed. The fluidized bed reactor can adjust the dosage of a catalyst and the flow velocity of a heat exchange medium according to the gas treatment amount, and the load change resistance is high.