34results about How to "Inhibition of the reverse reaction" patented technology

The invention provides a photocatalytic reaction method, comprising the steps of: atomizing a solution or suspension containing a photocatalyst and a reactant to form mist; and leading the mist to be subjected to photocatalytic reaction by utilizing a light source. The invention also provides a photocatalytic reaction device, which comprises a reaction vessel, an atomizer arranged inside or outside the reaction vessel, a condensation sleeve communicated with the reaction vessel, and the light source used for photocatalytic reaction. By means of the method and the device, a gas-liquid interface is enlarged by changing the form of water, i.e. atomizing the liquid-phase solution of the catalyst, so as to reduce the escape path of hydrogen gas and effectively inhibit the occurrence of reverse reaction, meanwhile, because the scattering probability of light in the mist is increased and the effective absorption is enhanced, the light utilization rate and the catalytic efficiency of the photocatalyst are greatly improved.

The invention discloses a method for continuously polymerizing nylon from a bi-component monomer serving as a raw material. The method comprises the following steps of: reacting and rectifying a nylon salt aqueous solution serving as a raw material in a pre-condensing tower in which a liquid phase is a continuous phase, a gas phase is a dispersed phase and falling liquid and rising bubbles keep flat push flow respectively under a low pressure to generate a prepolymer of which the polymerization degree 5-50 (preferably 20-40) and a terminal carboxyl group, a terminal amino group and the like are of equal molar amounts; and pre-heating the pre-polymer to generate a polymer of which the polymerization degree reaches process indexes in the pre-condensing tower. In the pre-condensing tower, a film falling or strip falling method is adopted, so that evaporation of condensed water is accelerated, the reaction temperature is lowered, reaction time is shortened, and gel is reduced; and a kettle wall is coated with a falling liquid film, so that kettle wall scars are avoided. The method has the advantages of short flow, large mono-line scale, saving in investment, low running cost, good product quality, long continuous running period, environment friendliness and suitability for continually polymerizing nylon 66, nylon 56 and other nylon made of bi-component monomers serving as raw materials.

The invention discloses a method for synthesizing 4-fluoro-2-nitroaniline through a micro-channel reactor. The method is characterized by comprising the steps; adopting a Corning high-flux continuousflow micro-channel reactor, with the molar ratio of p-fluoroacetanilide to nitric acid being 1:(1.0-1.5) as a benchmark, respectively setting the flow rates of an acetic acid-acetic anhydride solutionof 20%-40% of p-fluoroacetanilide and 68% of nitric acid to be 40.0-100.0 mL/min and 4.0-30.0 mL/min, and preheating; carrying out a reaction for 50-200 s at a temperature of 30 DEG C-70 DEG C; and dissolving the product in water, carrying out hydrolysis reaction at the temperature of 90 DEG C-100 DEG C for 2-4 h, stirring in ice water at the temperature of 0 DEG C-5 DEG C for 0.5 h, filtering, washing a filter cake until the filter cake is weakly acidic or neutral, adding petroleum ether, mixing, and drying to obtain the orange solid 4-fluoro-2-nitroaniline with the yield of 83-94%. The method has the advantages of short time, high efficiency, few byproducts and safe, stable and controllable reaction process.

The invention provides a method and a device for catalytic preparation of hydrogen from naphthenic hydrocarbon. The method comprises the following steps of: fixing a catalyst at the bottom of a reactor after the catalyst is washed by absolute ethyl alcohol; vacuumizing the reactor and introducing nitrogen into the reactor; heating the bottom of the reactor under nitrogen protection to ensure that the temperature of the catalyst slowly rises; stopping introducing the nitrogen after the catalyst is dried to open an organic liquid condenser; setting a dehydrogenation reaction temperature; heating the bottom of the reactor to be the dehydrogenation reaction temperature; injecting and feeding the naphthenic hydrocarbon at a constant velocity; discharging the generated hydrogen from the system after condensation and separation; and condensing the other steam components in a condenser and gathering the components into a product storage tank. By the method and the device, a precious metal catalyst is replaced by cheap raney nickel, so that the reaction cost is reduced, and the catalytic effect of the catalyst is good; the feeding is carried out in a jetting mode under a wet-and-dry multi-phase reaction condition, so that the dehydrogenation reaction efficiency is improved; and the gas is not needed to be carried or blown, the prepared hydrogen is high in purity and not needed to be separated again.

The invention provides a method for continuously preparing glyceryl triacetate with a phenyl phosphate biomimetic catalyst, and belongs to the field of synthesis of chemical products. Glycerinum, acetic acid, a catalyst and a solvent are pumped into a microchannel reactor and are subjected to an esterification reaction under the catalytic action of the phenyl phosphate catalyst, and an obtained product and acetic anhydride are subjected to an acylation reaction to obtain glyceryl triacetate. The phenyl phosphate biomimetic catalyst is adopted, the acidity of the phenyl phosphate biomimetic catalyst is relatively low as compared with that of a liquid acid, the equipment is less corroded, and the phenyl phosphate biomimetic catalyst is a bifunctional small-molecule catalyst and is higher in catalytic efficiency under the action of a hydrogen bond, the conversion rate of glycerinum is up to 100%, and the yield of glyceryl triacetate is up to more than 95%.

The invention discloses a high-purity methyl acetate production process device and method. The high-purity methyl acetate production process device comprises a reactive distillation column and a plurality of external reactors, wherein the reactive distillation column is dividend into a methyl alcohol separation section, a multilayer reaction section, an extraction section and a rectifying section from bottom to top. The multilayer reaction section is of a multilayer tower plate structure. The reaction section of each layer of tower plate is circularly connected with the corresponding external reactor through a pipeline. The extraction section is communicated with the multilayer reaction section and is provided with an acetic acid inlet. The top of the rectifying section is further connected with a condenser and a return tank. The separation section is provided with a methyl alcohol inlet, and the bottom of the separation section is circularly connected with a reboiler. Reaction and separation are organically combined, so that a reaction rate is increased, reverse reaction is suppressed, and a conversion rate is effectively improved. Therefore, the mass concentration of methyl acetate products is improved, and the device can be used for producing high-purity (97% or more) methyl acetate products and has the advantages of simplicity, high efficiency, remarkable economic benefits and the like.

The invention discloses a technique based on vacuum and high temperature conditions to synthesize linalyl acetate. Linalyl acetate is synthesized from natural linalool and acetic anhydride via the steps of I, adding materials into a reactor in the ratio of 1:1, adding potassium carbonate accounting for 0.8-1.5% of total quantity of the reaction materials into the reactor as a catalyst; II, importing the generated product into a washing kettle, and adding an alkaline solution into the washing kettle; III, rectifying. The technique based on vacuum and high temperature conditions to synthesize linalyl acetate has the advantages that esterification is carried out under vacuum and high temperature; the esterification is reversible; pressure and temperature may effectively inhibit reverse reaction of the generated product and increase the speed of forward reaction; potassium carbonate is used as the catalyst during reacting so that the yield of product reaches 70% and above.

The invention provides a semiconductor photocatalytic complete water splitting method capable of inhibiting reverse reaction. The surface of a semiconductor photocatalyst loaded with precious metal (Rh, Pt, Pd and the like) assistants is modified with a trace amount of Al2O3, SiO2 and other oxides through a powder atomic layer deposition method, so that the reverse reaction in the photocatalytic water splitting process is effectively inhibited. Different from other publicly reported reverse reaction inhibition methods, the modification strategy provided by the invention does not obviously increase the substance transfer resistance between the assistants and the solution environment, and does not introduce competitive side reactions, so that the water splitting performance of the photocatalyst can be greatly improved. The strategy can be used for inhibiting the hydrogen-oxygen reverse reaction in the photocatalytic complete water splitting reaction, and can also be used for preventing the hydrogen-oxygen composite reaction in the atmosphere due to safety factors in the presence of other noble metals.

The invention provides a preparation method, a prepared ketene compound and application of the compound, the preparation method comprises the following steps: 1) high-temperature cracking: preheating and gasifying an organic acid or anhydride cracking raw material, and then carrying out high-temperature cracking to obtain high-temperature cracking gas; 2) gas-liquid separation: conveying the high-temperature cracked gas into a cyclone separator for gas-liquid rapid separation; and (3) collecting a product: absorbing a gas-phase product from the cyclone separator through an absorbent or condensing the gas-phase product, and collecting the gas-phase product to obtain the ketene compound. According to the method, the cyclone separator is used for carrying out rapid gas-liquid separation on the cracking product, so that the reverse reaction of the gas-phase product due to overlong retention time in the liquid phase can be effectively avoided.

The invention belongs to the technical field of photocatalytic water decomposition, and particularly relates to a photocatalytic full-water-splitting cocatalyst which comprises metal nanoparticles with the performance of catalyzing carbon graphitization and a graphite-phase carbon cage thin layer coating the surfaces of the metal nanoparticles. In addition, the invention also relates to a photocatalyst which comprises a semiconductor powder photocatalyst and a cocatalyst loaded on the semiconductor powder photocatalyst, and the cocatalyst is the photocatalytic full-water-splitting cocatalyst. In addition, the invention also relates to a preparation method of the photocatalyst. Compared with the prior art, the catalytic effect on the reverse reaction is inhibited on the basis of not influencing the acceleration of the positive reaction.

The invention discloses a method for removing mercury and mercury-containing compounds from oxygen-enriched combustion flue gas. The method comprises the following steps: S01, acquiring combustion flue gas containing main components of CO2, H2O and O2, wherein the smoke contains 73%-97% of CO2, 1%-26% of H2O, 1%-5% of O2, and 0.02%-0.05 % of HCl in volume ratio; S02, transporting the recycled fluegas carrying activated carbon powder in the step S01 to a plasma reactor, and carrying out low temperature plasma treatment, so as to make the combustion flue gas components in a highly active atom or ionic state through plasma and form active functional groups on activated carbon to achieve adsorption and removal of mercury in the combustion flue gas; S03, delivering a mercury removal adsorbentto the mercury-containing combustion flue gas and attaching to a combustion flue gas filtering device, so as to form a fluidized bed for collecting and removing mercury and mercury compounds from thecombustion flue gas; and S04, updating the adsorbent on the fluidized bed, namely updating the mercury removal adsorbent on the filtering device every 120 minutes. The modified activated carbon is used for removing mercury and compounds from flue gas, and the mercury removal efficiency is high.

The invention discloses methyl salicylate synthesis equipment which comprises a reaction kettle, a batching device for batching the reaction kettle, a dehydration device for reaction dehydration, anda support device for supporting the reaction kettle and the dehydration device, excessive methanol is added, and the pressure intensity is enhanced through a pressurizing device, so that volatilization of methanol is effectively inhibited, and the yield of methyl salicylate and the reaction rate of esterification reaction are increased; water generated by reaction in the first kettle body is reduced through continuous dehydration, and the effects of inhibiting reverse reaction of esterification reaction and improving the conversion rate of methyl salicylate are achieved by replacing addition of a water-carrying agent; the treatment device condenses and reflows methanol volatilized by the first kettle body, and when dehydration and methanol removal are performed in the second kettle body, the treatment device also condenses and reflows the volatilized methanol, so that the utilization rate of the methanol is increased.

The invention discloses a two-dimensional carbon-nitrogen-based composite material photocatalyst and its preparation method and application, and relates to the technical field of photocatalytic materials. The two-dimensional carbon-nitrogen-based composite material is a two-dimensional carbon-nitrogen material loaded with transition metal elements The prepared two-dimensional carbon-nitrogen-based composite material can reduce the band gap to form a Z-scheme system, the top of the valence band is lower than the oxidation potential of water, and the bottom of the conduction band is higher than the reduction potential of water. In the present invention, electrons can be effectively transported inside the Z-scheme system composed of a two-dimensional carbon-nitrogen-based composite material photocatalyst, and the photocatalyst can simultaneously perform two reactions of hydrogen production and oxygen production on two reaction sites, and Since the band gap of the composite material is reduced after the transition metal ions are loaded, light energy in the visible range can be effectively utilized, and the problem of difficult transport of existing reactive electrons at the interface can be solved.