43results about How to "High conversion rate of methanol" patented technology

The invention discloses a preparation method of a high-efficiency nitrogen-doped carbon nanotube. The preparation method comprises the following steps: adding a multiwalled carbon nanotube into a nitric acid solution; closing the solution in an autoclave; pressurizing to 0.4 to 1.0 MPa, and stirring; then heating to 120 to 200 DEG C and keeping for 1 to 4 hours; finally, cooling to room temperature by the autoclave; washing to neutral and carrying out suction filtration and drying; mixing the carbon nanotube with a melamine solid according to the mass ratio being 1 to (1 to 4), and uniformly grinding by using mortar; and carrying out high-temperature sintering in nitrogen, washing to neutral and then drying to obtain the nitrogen-doped carbon nanotube. The nitrogen doping amount of the high-efficiency nitrogen-doped carbon nanotube disclosed by the invention is 4.6 to 10.3 weight percent.

The invention discloses a catalyst for synthesizing dimethyl carbonate by methanol liquid-phase oxidative carbonylation and methods. The catalyst comprises a copper halide and an ionic liquid; the mass ratio of the copper halide to the ionic liquid is 1:(1-10); a cation of the ionic liquid is an imidazole cation, a quaternary ammonium salt cation or a pyridine cation; and an anion of the ionic liquid is a halogen ion. The catalyst disclosed by the invention has relatively high methanol conversion ratio and high dimethyl carbonate selectivity and has an industrial application prospect. In addition, due to the addition of the ionic liquid, corrosion to stainless steel reaction equipment can be relieved.

The invention relates to a method for preparing methyl acetate through a carbonylation reaction of methanol by using a gold-supported zeolite molecular sieve catalyst. Gold can strongly interact withSi-OHin the high-silicon zeolite when the nano gold is loaded on the high-silicon zeolite. A bifunctional catalyst having a metal activity and acidity can be produced. The molecular sieve refers to atitanium-silicon zeolite molecular sieve and a high-silicon zeolite molecular sieve. Preparation of a supported gold catalyst by deposition and precipitation under negative pressure is beneficial to purifying the inner and outer surfaces and pore channels of the molecular sieve, so that the gold easily enter the pore channels of the molecular sieve, and the highly-dispersed gold-supported zeolitemolecular sieve catalyst is obtained. When the supported gold catalyst prepared by the method is used for the carbonylation reaction of the methanol, the strong acid center and the metal active centerwhich are required by the carbonylation of the methanol enable the methanol to react to generate methyl acetate and methyl formate under the double-function action of the metal and the acid.

The invention relates to supported copper-based catalysts for hydrogen production by methanol steam reforming as well as a preparation method and application of the supported copper-based catalysts. According to the invention, magnesium-and-aluminum-supported copper-based catalysts with different magnesium-to-aluminum molar ratios are prepared by roasting a hydrotalcite precursor, wherein the supported copper-based catalyst is a Cu-Mg-Al composite oxide, a molar ratio of Mg to Al in the Cu-Mg-Al composite oxide is 2: 5 to 5: 2, and the mass fraction of CuO is 10%-30%. Compared with the prior art, the catalyst provided by the invention has the advantages that through doping modification of a single oxide carrier, a methanol conversion rate is greatly improved on the basis of keeping high hydrogen selectivity, and particularly, the methanol conversion rate is improved by nearly one time at a low-temperature section (225 DEG C) without generation of CO, so a basis is provided for application of the catalyst to a fuel cell; the stability of the catalyst is higher than the stability of commercial Cu/ZnO/Al2O3, and the bottleneck that the activity, selectivity and stability of an existing catalytic system cannot be obtained at the same time is overcome; and the preparation method is simple, the magnesium/aluminum ratio is adjustable, and the method is suitable for large-scale industrial production.

The invention discloses a composite catalyst, a preparation method thereof and a method for preparing methyl acetate and acetic acid through methanol carbonylation by using the composite catalyst. Thecomposite catalyst is formed by compounding a water-vapor shift catalyst and a modified H-MOR molecular sieve. The composite catalyst comprises a water vapor shift catalyst and a carbonylation catalyst; the carbonylation catalyst comprises a modified H-MOR molecular sieve; the modified H-MOR molecular sieve is an H-MOR molecular sieve subjected to organic alkali treatment. The composite catalystis used for methanol carbonylation, and the selectivity of methyl acetate exceeds 80%.

The invention discloses a molecular sieve based catalyst and a preparation method thereof as well as application to the side chain alkylation reaction of methyl alcohol and methylbenzene. The preparation method specifically comprises the steps that a water source is added into a silicon source to dilute, then a template agent, an aluminum source and a sodium source are added sequentially and stirred uniformly after each adding is completed, and a liquid mixture is obtained; a silylating reagent is added after the liquid mixture is subjected to ageing at the room temperature and stirred uniformly, a crystallization reaction is conducted under the moderate and continuous stirring conditions after the materials are stirred uniformly, the product is washed and filtered after the reaction is ended, the obtained solid is dried and calcinated, and a molecular sieve based catalyst precursor is obtained; and the molecular sieve based catalyst precursor is placed into an alkali metal salt solution to be subjected to alkali metal ion exchanging, the obtained exchanged sample is filtered, dried and calcinated, and the molecular sieve based catalyst is obtained. The molecular sieve based catalyst is specifically applied to preparing styrene in the side chain alkylation reaction of methyl alcohol and methylbenzene. The physical and chemical features of the molecular sieve based catalyst arechanged by optimizing the preparation conditions of the molecular sieve, and the methyl alcohol conversion rate, and the selectivity and yield of styrene are finally and effectively improved.

The invention provides a catalyst for preparing methylal and methyl formate through one-step selective oxidation of methanol. The catalyst comprises the following raw material components in percentage by mass based on total mass of the raw material components of the catalyst: 10-20% of a vanadium source, 55-65% of a titanium source and 15-35% of sulfuric acid. The invention provides a catalyst for preparing methyl formate and methylal through one-step selective oxidation of methanol and a preparation method of the catalyst. The catalyst has a high methanol conversion rate, high product selectivity, long life and low-temperature fluctuation sensitivity, the product composition is easily controlled in industrial reaction, and subsequent separation is convenient.

The invention relates to the field of methanol steam reforming hydrogen production and discloses an ultrasonic-assisted methanol steam reforming hydrogen production reactor. The reactor comprises a reactor main body, an inner chamber formed from the reactor main body is used as a reaction chamber, the reactor main body is provided with an ultrasonic probe and an ultrasonic horn connected to the ultrasonic probe, and two ends of the reactor main body are provided with a material inlet for introducing a methanol aqueous solution and a material outlet for discharging hydrogen gas. Along a material flowing direction, the reaction chamber orderly comprises an evaporation zone containing an evaporation plate and a reforming zone containing a metal carrier reaction plate. The ultrasonic-assistedmethanol steam reforming hydrogen production reactor has the advantages of high reforming hydrogen production efficiency and high methanol conversion rate in hydrogen preparation from the methanol aqueous solution.

The patent of the invention belongs to the technical field of chemical industry, and specifically relates to the preparation and application of a catalyst for preparing anhydrous formaldehyde by direct dehydrogenation of anhydrous methanol. The catalyst uses one or both of copper and zinc oxide as the active ingredient, the corresponding metal salt as the precursor, sodium carbonate, etc. as the precipitating agent, and the sample is prepared by the deposition precipitation method, and then filtered, washed, dried and The catalyst is finally prepared by roasting and other processes. The catalyst prepared by the method shows high activity, selectivity and stability in the process of catalyzing the dehydrogenation of anhydrous methanol to produce anhydrous formaldehyde. At a temperature of 400-600°C, nitrogen is used as a carrier gas, the feed ratio of methanol is in the range of 1-40 vol%, the conversion rate of methanol is 10-90%, and the selectivity of formaldehyde is as high as 60-99%. The preparation process of the catalyst is simple, the cost is low, the catalytic effect is good and the stability is high, and the catalyst has potential industrial application prospects.

The invention discloses a miniature methanol and steam reforming chamber which is made from an aluminum alloy material. The miniature methanol and steam reforming chamber comprises an aluminum alloy main body, an aluminum alloy packaging end plate and a miniature flow field structure, wherein the miniature flow field structure is used as a gas circulating channel in the reforming chamber, and located between the aluminum alloy main body and the aluminum alloy packaging end plate and on the surface of the aluminum alloy main body. One layer of porous ceramic thin film grows on the surface of a runner of the miniature flow field structure inside the reforming chamber through a micro-arc oxidation method, and a reforming reaction catalysis layer is formed on the ceramic thin film through a full-filling method. According to the miniature methanol and steam reforming chamber, one layer of porous oxide ceramic film is prepared inside the reforming chamber by applying a micro-arc oxidation technology, so that the adhesive capacity of the reforming catalyst in the miniature runner of the reforming chamber is improved, the contact area between a reactant and the catalyst is increased, and the efficiency of reaction between methanol and steam and the conversion rate of the methanol are increased.

The invention discloses a copper-based catalyst for hydrogen production by methanol steam reforming and a preparation method and application thereof, CuO is used as a main active component, the copper-based catalyst also comprises ZnO, Al2O3, ZrO2, CeO2 and an auxiliary agent MxOy, and MxOy is one of MgO, La2O3, CaO or MnO. The catalyst is applied to methanol steam reforming hydrogen production reaction, and has the advantages of high methanol conversion rate, low CO content in reforming tail gas, good low-temperature activity, strong thermal stability and the like. The preparation process is simple, raw materials are cheap and easy to obtain, and the method has a good industrial application prospect.

The invention discloses a synthesis method of methyl chloroformate, and belongs to the technical field of production of methyl chloroformate. The synthesis method of the methyl chloroformate comprises the following steps: step 1, purifying methanol; step 2, gasifying methanol; step 3, synthesizing phosgene; and 4, carrying out gas-phase esterification reaction. Gas-phase reaction of methanol gas and phosgene is utilized, and contact among gas-phase reaction molecules is more sufficient than contact among gas-liquid reaction molecules, so that the conversion rate of methanol is increased; through the arrangement of a circular baffle, a rotating shaft, a circulating gas pipe and a circulating pump, the mixing degree and the contact time between methanol gas and phosgene are increased, so that methanol reaction is more sufficient, side reaction of excessive methanol and methyl chloroformate is avoided, and the purity of methyl chloroformate and the conversion rate of methanol are improved; and methanol gas and phosgene are introduced by means of batch circulation, so that the phosgene is always excessive, and meanwhile, the phosgene is not excessive, and the tail gas treatment pressure is reduced.

The present invention provides an improved process for the preparation of phosphorous containing mesoporous alumina catalyst for selective dehydration of methanol to dimethyl ether. The process provides a single step selective vapour phase dehydration of methanol to produce dimethyl ether over phosphorous containing mesoporous alumina (P/Al2O3) catalyst at a temperature in the range of 150-350° C. The process provides methanol conversion of 45-100% with a selectivity of the DME up to 100%.