16results about "Ketenes preparation" patented technology

The present application relates to a kind of 2,2,4,4-tetramethyl-1,3-cyclobutanedione preparation method.The present application first mixes isobutyric anhydride, small molecule alcohol and organic acid and carries out high-temperature cracking, so that isobutyric anhydride in it is cracked to generate isobutyric acid and dimethyl ethylene ketone, and the isobutyric acid generated simultaneously is esterified with small molecule alcohol under the action of organic acid to generate isobutyrate;The product after cracking is separated, and dimethyl ethylene ketone is absorbed using the isobutyrate obtained by separation, and dimerization is obtained 2,2,4,4-tetramethyl-1,3-cyclobutanedione.The present application can obtain higher yield under the same operating load, reduce the generation of carbon deposition and the corrosion to equipment in the reaction process, long running cycle, and low equipment investment.

The application belongs to the technical field of catalytic chemistry and porous materials, and specifically discloses a kind of vacancy anchoring full-silicon core-shell monatomic catalyst and its preparation method, the application makes Fe highly dispersed in the form of monatomic through the synergistic anchoring effect of silicon vacancy and ligand, avoids the metal oxide cluster produced by traditional impregnation method, inhibits excessive pyrolysis caused by local overheating, reduces the generation of gas impurities such as low-carbon alkane, the crystalline shell layer of the catalyst shortens the diffusion path of the product dimethyl ethylene ketone, DMK molecules can be quickly desorbed and leave the active center after generation, the content of by-product dimers is reduced, the structure of the catalyst improves the feed rate and accelerates the product diffusion, prevents the secondary reaction of reaction intermediates in the pore, greatly reduces the carbon deposition rate, forms a hydrophobic gradient layer by MTES modification, effectively repels the associated by-products isobutyric acid generated in the reaction, blocks the DMK polymerization reaction, thereby maintaining the yield of the target product DMK.

The application discloses a gas-liquid separation assembly, a gas-liquid separation device and application and a preparation method of dimethyl ethylene ketone, and comprises a cooling unit, a gas-liquid separation unit and a gas collecting unit which are arranged in a nested mode from inside to outside; wherein the gas-liquid separation unit and the cooling unit make the gas-liquid mixture to be separated pass through the cooling unit to be cooled and simultaneously perform gas-liquid separation to obtain a gas phase and a liquid phase; the gas collecting unit is used for collecting the gas phase, and the gas-liquid separation unit is provided with a liquid collecting part which is used for collecting the liquid phase. The application has the advantages of in-situ cooling and gas-liquid separation.

The present disclosure relates to a solvent drying solution and processes therefor. The present disclosure more specifically relates to a solvent drying solution that in use releases water from a solvent mixture. The present disclosure also relates to a process for recovering a solvent drying solution, more specifically to a process for recovering a solvent drying solution by using an osmotic process.

The application provides a supported metal oxide catalyst, which is prepared by using a Zr-modified silicon-based molecular sieve containing F as a carrier and loading active metal oxides on the carrier, wherein the silicon-based molecular sieve has two independent pore structures, and the active metal oxides are oxides of one or more of Ti, Ca, Sr, Rb and Cs. The application also provides a preparation method and application of the supported metal oxide catalyst. The application further provides a method for preparing dimethyl ethylene ketone by cracking isobutyric acid. The dimethyl ethylene ketone is prepared by using the supported metal oxide catalyst provided by the application to catalyze the cracking reaction of isobutyric acid, the conversion rate of isobutyric acid is high, the selectivity of the target product is good, and the service life of the catalyst can be greatly prolonged, thereby providing a solid foundation for the large-scale production and application of dimethyl ethylene ketone.

The invention provides a method for preparing dimethyl ketene by cracking isobutyric anhydride, which comprises the following steps of: cracking isobutyric anhydride serving as a raw material at high temperature to generate a cracking product containing dimethyl ketene and isobutyric acid, and then condensing and carrying out gas-liquid separation to obtain the dimethyl ketene. The content of the dimethyl ketene-beta-lactone dimer in a liquid phase product output by gas-liquid separation is controlled to be 5 to 5000 ppm, preferably 50 to 1000 ppm, and more preferably 100 to 500 ppm. By controlling the content of key impurities in the cracking product, the yield of the dimethyl ketene is higher, the coking condition of the condenser is obviously relieved, the operation cycle can be prolonged, and the production cost is reduced.

The invention discloses a synthetic method of 3-oxo-1-cyclobutane carboxylic acid, and belongs to the technical field of organic synthesis. The synthesis method comprises the following steps: S1, reacting chloroacetyl chloride with methyl acrylate in a solvent to generate 2, 2-dichloro-3-oxocyclobutane carboxylic acid methyl ester; s2, carrying out reductive dehalogenation on the 2-dichloro-3-oxocyclobutane carboxylic acid methyl ester, and converting the 2-dichloro-3-oxocyclobutane carboxylic acid methyl ester into 3-oxo-1-cyclobutane carboxylic acid methyl ester; and S3, carrying out a hydrolysis reaction on the 3-oxo-1-cyclobutane carboxylic acid methyl ester, so as to obtain the 3-oxo-1-cyclobutane carboxylic acid. The synthesis method of the 3-oxocyclobutane carboxylic acid is mild in reaction condition, high in yield and stable in product quality.

A synergistic polymerization inhibitor composition, the composition having a copper salt, and a manganese salt; a copper salt or a manganese salt, and a cationic polymer; or a phenothiazine and a manganese salt. A method for inhibiting polymerization of unsaturated polymerizable monomers, the method providing adding a synergistic polymerization inhibitor composition to an methacrylic acid manufacturing system or component thereof, the composition having a copper salt, and a manganese salt; a copper salt or a manganese salt, and a cationic polymer; or a phenothiazine and a manganese salt.

The invention relates to the technical field of chemical production, and provides a low-temperature preparation method of ketene. According to the method, the high-activity auxiliary is added in the acetic acid cracking process to initiate the acetic acid cracking reaction, so that the cracking temperature is reduced, the side reaction is reduced, the selectivity of ketene is improved, and the energy consumption is reduced; meanwhile, nitrogen oxide and the like generated after the aid is decomposed at high temperature have polymerization inhibition effect, so that the auto-polymerization of the gas-phase ketene can be prevented, the problem that the ketene is difficult to store is solved, and the effect of'one agent with double effects' is realized.

A synergistic polymerization inhibitor composition, the composition having a copper salt, and a manganese salt; a copper salt or a manganese salt, and a cationic polymer; or a phenothiazine and a manganese salt. A method for inhibiting polymerization of unsaturated polymerizable monomers, the method providing adding a synergistic polymerization inhibitor composition to an methacrylic acid manufacturing system or component thereof, the composition having a copper salt, and a manganese salt; a copper salt or a manganese salt, and a cationic polymer; or a phenothiazine and a manganese salt.

This invention provides a method and system for the rapid separation of dimethyl ketene (DME) from isobutyric anhydride. The method includes: the pyrolysis gas from the cracking reaction of an anhydride-based raw material (such as isobutyric anhydride) is adsorbed by an adsorbent material and cooled and separated by acoustic treatment; the resulting gaseous product is then absorbed or condensed to obtain an ketene compound. This invention utilizes an adsorbent material superimposed with an acoustic field-enhanced coalescence-condensation system, which promotes droplet aggregation, efficiently separates droplets carried in the gas, rapidly reduces the temperature of the cracking reaction gas, quickly separates DME, avoids side reactions during the process, increases the yield of ketene compounds, improves product selectivity in downstream polymerization reactions, and thus reduces the production cost of DME.

The present invention relates to processes for making vinyl acetate, based on methanol having a deuterium content below 90 ppm, comprising the step of reacting acetic acid with ethylene to give vinyl acetate, and to processes for making vinyl acetate, based on methanol having a deuterium content below 90 ppm, comprising the steps of reacting acetic anhydride with acetaldehyde to form ethyliden diacetate and reacting ethyliden diacetate to give vinyl acetate by thermal elimination of acetic acid, as well as to vinyl acetate having a deuterium content below 90 ppm, based on the total hydrogen content. The present invention further relates to a vinyl acetate having a natural abundance of carbon-14 from non-fossil resources, preferably from biomass, as well as to its use. The present invention also relates to a process for preparing alkoxylated compounds comprising ethylene oxide units and / or propylene oxide units, comprising the steps: (a) reacting hydrogen with carbon dioxide to form methanol, (b) converting the methanol from step (a) to ethene and / or propene, (c) reacting the ethene and / or propene from step (b) with oxygen or an oxidizing agent to form ethylene oxide and / or propylene oxide, and (d) reacting the ethylene oxide and / or propylene oxide with the at least one starter unit having Zerewitinoff active hydrogen atoms to form the alkoxylated compound, wherein the carbon dioxide in step (a) is at least in part captured from industrial flue gases or from air or from ocean water or other natural waters or obtained from biological processes; and the alkoxylated compounds obtainable by the process. The invention further relates to graft polymer based on ethylene oxide-comprising backbones being grafted with olefinically polymerizable monomers, preferably vinyl monomers, more preferably with a) vinyl esters or b) vinyllactams, wherein such graft polymer is at least partially based on hydrogen from non-fossil-based sources, wherein the molar share of deuterium is lower in such graft polymer than that in the identical chemical compound when derived solely from fossil-based sources.

The invention provides a preparation method of 2, 2, 4, 4-tetramethyl-1, 3-cyclobutanedione, and belongs to the technical field of compound synthesis. The preparation method provided by the invention comprises the following steps: mixing isobutyric acid, a catalyst and a drying agent, and carrying out dehydration dimerization reaction to obtain 2, 2, 4, 4-tetramethyl-1, 3-cyclobutanedione; the catalyst comprises hard carbon and transition metal oxide loaded on the surface of the hard carbon; the temperature of the dehydration dimerization reaction is 150 to 200 DEG C. The catalyst is added, isobutyric acid can be decomposed under the action of the catalyst at a low temperature to generate dimethyl ketene, then 2, 2, 4, 4-tetramethyl-1, 3-cyclobutanedione is obtained through dimerization, and meanwhile the yield of the product is increased. The result of the embodiment shows that the reaction temperature of the preparation method provided by the invention is 150-200 DEG C, and the molar yield of the product is 69% or above.

This invention relates to a method for preparing propadienone using a specific catalyst, which is CuSO4 or CuSO4 hydrate. The reaction provides propadienone in high yield and with high selectivity.

Disclosed is a process for producing acetic acid by reacting wood with acetic anhydride, thereby forming acetylated wood and acetic acid. The wood is rubberwood, which allows producing acetic acid devoid of terpene and / or terpene-derived impurities.

A synergistic polymerization inhibitor composition, the composition having a copper salt, and a manganese salt; a copper salt or a manganese salt, and a cationic polymer; or a phenothiazine and a manganese salt. A method for inhibiting polymerization of unsaturated polymerizable monomers, the method providing adding a synergistic polymerization inhibitor composition to an methacrylic acid manufacturing system or component thereof, the composition having a copper salt, and a manganese salt; a copper salt or a manganese salt, and a cationic polymer; or a phenothiazine and a manganese salt.