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 relates to a method for producing ethylene and ethane and a catalytic reactor, belonging to the technical field of lower hydrocarbon. The method comprises the following steps of: carrying out first methane catalytic conversion reaction on a methane-rich feed gas and an oxidizing gas by using a first section of granular catalytic agent, carrying out second methane catalytic conversion reaction on the gas mixture entering a second integrated type catalytic agent reaction section after supplementing the oxidizing gas in a reaction gas mixture, and finally collecting a reaction product. A premixing chamber which is provided with a feed gas inlet and an oxidizing gas inlet is arranged at the top of the catalytic reactor; a first reactor in which a granular catalytic agent is placed is communicated with the lower end of the premixing chamber; an oxidizing gas replenisher is communicated with the first reactor; a second reactor in which an integral catalytic agent is placed is communicated with the oxidizing gas replenisher; and a product outlet is arranged at the lower end of the second reactor. The catalytic reactor has the advantages that the single-pass methane conversion rate of the methane catalytic conversion reaction is increased, the technological process is short, the operation is stable, and the equipment investment is few.

The invention discloses a reaction device and method for preparing ethylene by oxidative coupling of methane. The reaction device includes a riser, an oxidizer, a stripper, a pre-stripper, a pre-lift section, and a cyclone separator; the reaction device adopts the method of separate feeding of methane and oxygen, multi-mode operation, and flexibly controls the flow rate of oxygen. supply, realizing the flexible control between the two reaction mechanisms. There is no contact between oxygen and methane in the feed; after the reaction, products such as ethylene are directly drawn from the reactor without mixing with oxygen. The reactor and the oxidizer are coaxially arranged, wherein the reactor is at the lower part, the oxidizer is at the upper part, and the riser is used as the reactor for the reaction. The invention realizes the complete separate feeding of oxygen and methane in the process of methane oxidative coupling reaction, eliminates the contact between the product and oxygen, avoids the deep oxidation of the product, reduces the generation of non-selective products, and effectively improves the selectivity of ethylene and yield.

Hydrophobic modified core-shell catalyst ZIF‑67@SiO of the present invention 2 A method for preparing KA oil by catalytic cyclohexane oxidation. The present invention adopts the method of dehydration condensation to coat a layer of SiO on the surface of ZIF-67 material. 2 shell, to obtain a hydrophobically modified core-shell catalyst ZIF‑67@SiO 2 , by grafting hydrophobic groups on the surface to control the hydrophilic-hydrophobic properties of the catalyst surface, thereby regulating the adsorption and desorption behavior of cyclohexane, cyclohexanol and cyclohexanone, and avoiding the deep oxidation of alcohols and ketones. The modified catalyst surface has Good hydrophobic effect, the catalytic reaction shows that the conversion rate of cyclohexane and the selectivity of the target product are simultaneously improved, and the stability of the catalyst is also significantly improved.

The invention belongs to a reaction device with short gas-solid contact time and its application. The reaction device includes a riser reactor, a settling reactor, a gas-solid separator and a feeding device; the riser reactor is installed in the settling At the bottom of the reactor, the discharge port of the riser reactor is higher than the bottom discharge port of the settling reactor; the gas-solid separator is used for the separation of product gas and catalyst particles; the return device collects the bottom discharge port of the settling reactor The transported catalyst particles and the catalyst particles obtained by the gas-solid separator are returned to the bottom of the riser; the bottom of the riser is provided with a feed gas inlet pipe. The present invention realizes short-term contact between the catalyst particles and the gas through the riser reactor, avoiding the deep oxidation of target products such as ethylene, and at the same time, the catalyst particles carry the reaction heat and perform heat exchange outside the reactor, so that the temperature of the hot spot in the reactor is reduced , which is conducive to improving the selectivity of the target product.

The invention belongs to the technical field of inorganic membrane reactors, and in particular relates to a preparation method of an oxygen-permeable-hydrogen-permeable-reaction three-effect tubular membrane reactor for hydrogen production by partial oxidation of methane: first prepare a tubular dense ceramic oxygen permeable membrane, a tubular dense ceramic permeable membrane Hydrogen membrane, nickel catalyst; set the tubular dense ceramic hydrogen permeable membrane on the outside of the tubular dense ceramic oxygen permeable membrane, install one end on the first sealing head, and then fill the nickel catalyst in the interlayer of the two tubular membranes; set the quartz tube On the outside of the hydrogen permeable membrane, one end of the quartz tube is installed on the first sealing head; then the quartz tube and the other ends of the two tubular membranes are sealed to the second sealing head to form a reactor. The invention can prevent the deep oxidation of methane; can also realize the instant separation of hydrogen and carbon monoxide, and can promote the movement of the reaction balance to the product direction. The invention solves the problem that the raw material separation of methane partial oxidation reaction, methane reaction and product separation cannot be carried out simultaneously in the same reactor.

The invention relates to a multi-level porous catalyst, which is composed of active components accounting for 30% to 60% of the total mass and the balance being SiO with three-dimensional ordered multi-level channels. 2 Carrier is made; In parts by weight, the active component consists of 17.66g / 35.32g (NH 4 ) 6 Mo 7 o 24 4H 2 O, 0.25g NH 4 VO 3 , 0.42g Cu(CH 3 C00) 2 2H 2 O, 0.48g SbCl 3 , 0.30g H 3 AsO 4 , 1.09g H 3 PO 4 , 0.35g La(CH 3 COO) 3 1.5H 2 O, 0.45g Ce(NO 3 ) 3 ·6H 2 O and 2.12g CsOH·H 2 O composition. At the same time, the invention also discloses the preparation method and application of the catalyst. The present invention can significantly improve the catalytic activity of the reaction, and it can be used to catalyze the oxidative dehydrogenation of isobutyraldehyde to prepare methacrylic acid, which can be carried out under normal pressure conditions with air as the oxidizing agent, and can obtain higher formazan under lower reaction temperature conditions. Acrylic acid yield and lower CO X generation rate.

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 preparation method of a halogen doped perovskite composite oxide catalyst and an application thereof in the aspect of catalyzing methane oxidative coupling, belonging to the field of nonhomogeneous catalysis. The halogen element doped composite oxide catalyst with a pure phase perovskite structure is prepared by using the EDTA-citric acid method, and the composite oxidecatalyst is applied to methane oxidative coupling reaction. Results show that the catalytic performance of the halogen element doped material in methane oxidative coupling is greatly improved, and the catalyst shows good catalytic activity stability. Thus, the catalyst is an excellent catalyst for the methane coupling reaction to prepare ethane and ethylene.

The invention belongs to the technical field of inorganic membrane reactors, and in particular relates to a preparation method of an oxygen-permeable-hydrogen-permeable-methane partial oxidation dehydrogenation three-effect flat-plate membrane reactor and a test system thereof. The preparation method includes first preparing a dense ceramic oxygen permeable membrane, a dense ceramic hydrogen permeable membrane, and a nickel catalyst, and then spreading the nickel catalyst on the surface of the hydrogen permeable membrane; placing the corundum tube encapsulating the oxygen permeable membrane on the corundum tube encapsulating the hydrogen permeable membrane Inside, the core component is formed, and then the core component is placed in the quartz tube, and finally the sealing cap equipped with the gas channel is connected with the quartz tube to form the reactor. It can realize the continuous and controllable supply of oxygen to prevent the deep oxidation of methane; it can also realize the instant separation of hydrogen and carbon monoxide, and can promote the shift of the reaction balance to the product direction. The invention solves the problem that the raw material separation of methane partial oxidation reaction, methane reaction and product separation cannot be carried out simultaneously in the same reactor.

A preparation method of a self-supporting two-dimensional transition metal / metal oxide mixed-phase nanosheet relates to a preparation method of a two-dimensional nano material and solves the problems of complex technology, harsh reaction condition and poor electric conductibility of transition metal oxide in the conventional method for preparing the self-supporting two-dimensional transition metal / metal oxide mixed-phase nanosheet. The preparation method of the mixed-phase nanosheet comprises the following steps: firstly, inorganic transition metal salt, organic amine, alcohol and water are mixed to form a turbid liquid of an organic amine complex containing metal ions; secondly, the turbid liquid reacts under a high-temperature solvent thermal condition to generate a precursor of the metal / metal oxide mixed-phase nanosheet; finally, high-heat treatment is conducted under the protection of inert gas to control the crystallinity of the two-dimensional metal / metal oxide mixed-phase nanosheet. The preparation method provided by the invention has the advantages of simple technology and lower equipment requirement; the mixed-phase nanosheet prepared by the method has excellent electric conductibility.