36 results about "Adipic acid dimethyl ester" patented technology

The present invention relates to continuous esterification process and apparatus for producing dimethyl adipate in the presence of solid acid catalyst. The process includes the following steps: setting solid acid catalyst, adipic acid and methanol into pre-esterifying kettle; heating to 50-100 deg.c to react at normal pressure to obtain lean ester; feeding the supernatant with lean ester to the upper part of one continuous esterifying tower and methanol vapor to its lower part for countrecurrent reaction in the catalyst section at the temperature of 70-150 deg.c, liquid space velocity of 0.1-0.7 kg/kg.hr and methanol space velocity of 0.1-1.0 kg/kg.hr; rectifying the resultant at operation pressure of 0-0.01 MPa to obtain dimethyl adipate. The present invention has adipic acid converting rate up to 99 % and dimethyl adipate purity up to 99.8 %.

The invention discloses a method for producing 1,6-dimethyl adipate. The method comprises the following steps of: (1) mixing adipic acid and methanol without adding a catalyst, and performing pre-esterification reaction at the temperature of 80 and 200 DEG C under the gage pressure of between 0.05 and 3 MPa; and (2) conveying materials which are subjected to the pre-esterification reaction to the upper part of a continuous catalytic rectifying tower, and gasifying the dried methanol, conveying to the lower part of the catalytic rectifying tower, allowing the materials which are subjected to the pre-esterification reaction to contact methanol steam in a reverse flow mode in the catalytic rectifying tower and performing esterification reaction further. By the method, the problems of equipment corrosion and pollution which are caused by the utilization of a sulfuric acid catalyst in the conventional process are solved, and the defects of complex processes, large consumption level of the catalyst and the like which are caused by the adoption of two-step or multi-step catalytic esterification are overcome.

The invention discloses a method for preparing dimethyl adipate by continuous esterification, comprising the steps of (1) pre-esterifying mixture of adipic acid and methanol in a tubular reactor with an inner component on the catalyst-free condition, wherein the temperature is 90-180 degrees centigrade and the pressure is 0.05-3 MPa; (2), sending the pre-esterified product to upper part of a continuous catalytic rectifying tower; enabling the dried methanol to enter the lower part of the catalytic rectifying tower after being vaporized; enabling the pre-esterified material to contact the methanol steam in the catalytic rectifying tower in a counter-current manner; and further performing esterifying. The method overcomes the problems that the traditional process has device corrosion and pollution problem caused by the sulphuric acid catalyst, and has no continuous pre-esterification and large catalyst consumption.

The invention provides a method for preparing 1,6-hexylene glycol through dimethyl adipate gas-phase hydrogenation. The method comprises the following steps: by taking a hierarchical pore SiO2 molecular sieve as a carrier, loading a copper-based catalyst, mixing gasified dimethyl adipate with hydrogen, putting the mixture into a fixed bed reactor for reaction under a certain condition, a 1,6-hexylene glycol-containing liquid phase product is obtained. According to the method provided by the invention, by taking the SiO2 molecular sieve with ordered meso pores and micro pores as the carrier, the dispersity of copper serving as an active component is substantially promoted, and the number of effective active sites of the catalyst is increased; moreover, due to the adoption of an ammonia distillation method, the copper is loaded on the mesoporous silicon oxide molecular sieve, so that high dispersion of the catalyst is realized; furthermore, the ordered meso pores of the hierarchical pore SiO2 molecular sieve is retained, and the catalysis capacity is improved.

The invention discloses a catalyst for preparing 1, 6-hexanediol through hydrogenating dimethyl adipate. The catalyst is composed of a carrier and an active component dispersedly loaded on the carrier, wherein the active component is composed of a first active component and a second active component, the first active component is ruthenium and/or iridium, and the second active component is copperchromite; the carrier is a lanthanum doped SiO2/ZrO2 carrier; and the carrier is of a mesoporous structure, and the pore size of the carrier is 10-50 nm. The catalyst provided by the invention not only has the advantages of high dimethyl adipate conversion rate and strong 1, 6-hexanediol selectivity, but also has the excellent performances of large specific surface area, high active component loading capacity, stable performance and long service life. The invention further discloses a preparation method and application of the catalyst for preparing 1, 6-hexanediol through hydrogenating dimethyl adipate.

The invention discloses a method for preparing high-purity adipic acid dimethyl ester by catalytic gas stripping coupling technology. The method comprises the following steps: carrying out countercurrent contact on adipic-acid-containing liquid phase, methanol gas and inert gas in a gas stripping tower and carrying out reaction to generate water which is gas-stripped to the gas phase and recovered from the top of the gas stripping tower; obtaining high-purity adipic acid dimethyl ester from the tower bottom. The method of the invention features simple process, high purity of produced adipic acid dimethyl ester, no need of further refining and direct application as raw material for preparing 1,6-hexanediol.

The invention discloses a method for separating mixed diacid dimethyl ester. Mixed diacid dimethyl ester successively passes through a rectification tower 1, a rectification tower 2 and a rectification tower 3; dimethyl succinate is separated from the top of the rectification tower 1, dimethyl glutarate is separated from the top of the rectification tower 2, and dimethyl adipate is separated from the top of the rectification tower 3; the reflux ratio of the rectification tower 1, the rectification tower 2 or the rectification tower 3 is 0.5 to 3.0; the mixed diacid dimethyl ester is a product of esterification of methanol and mixed diacid by-produced in production of adipic acid, and comprises 10 to 30 wt% of dimethyl succinate, 40 to 60 wt% of dimethyl glutarate and 20 to 40 wt% of dimethyl adipate. With the method, the recovery rate and purity of dimethyl succinate, dimethyl glutarate and dimethyl adipate are more than 95 wt% and no less than 98%, respectively. According to the invention, a rectification apparatus is divided into the three rectification towers, each rectification tower is provided with 5 to 30 tower plates, the reflux ratio is controlled to be 0.5 to 3, energy consumption is low, the utilization rate of resources is high, and the advantages of easy realization of industrialization and low energy consumption are obtained.

The invention discloses a beta-hydroxyalkylamide curing agent preparation method, which comprises: (1) mixing dimethyl adipate or diethyl adipate and diethanol amine, adding a catalyst, heating, and carrying out pressure reducing distillation to remove volatile components to obtain a tetrahydroxyethyl adipamide solution, i.e., a product A, wherein the reaction equation formula is defined in the specification; and (2) curing the product A, breaking, and drying to obtain a white powder solid, ie., the qualified tetrahydroxyethyl adipamide (beta-hydroxyalkylamide). The method of the invention hasadvantages of high yield, no generation of wastewater, waste liquid and waste solid during preparation, environmental protection, less equipment investment and simple operation.

The invention discloses a method for preparing N,N,N',N'-tetra(beta-hydroxypropyl) adipamide, which comprises the following steps: (1) adding excessive diisopropanolamine and a basic catalyst into a reaction kettle, and then dropwise adding dimethyl adipate to prepare a crude product of N,N,N',N'-tetra(beta-hydroxypropyl) adipamide; (2) lowering the temperature in the reaction kettle to a set temperature, dropwise adding or adding neutralizing acid into the reaction kettle in batches under a vacuum condition so as to neutralize the excessive diisopropanolamine, and dehydrating at the same time; (3) after the neutralization is finished, adding a solvent into the reaction kettle, stirring and crystallizing, then filtering, and separating out diisopropanolamine sulfate, and subjecting the filtrate to distillation to separate the solvent so as to obtain the N,N,N',N'-tetra(beta-hydroxypropyl) adipamide product with high purity. According to the method, the unreacted diisopropanolamine raw material is separated by utilizing the high-amine ester, so that the preparation process is simple in flow and low in energy consumption, and the separated diisopropanolamine salt can be recycled as an industrial raw material.

The invention relates to the technical field of chemical processes, and particularly discloses a continuous esterification reaction system and a production method and application of dimethyl adipate, a continuous methanol separation system comprises a continuous esterification tower and a methanol raw material tank, the methanol raw material tank is used for storing methanol, the end of the esterification tower is communicated with a material tank used for storing pre-esterification liquid, and the material tank is communicated with the esterification tower. The stored pre-esterification liquid can be conveyed into the esterification tower and is subjected to esterification reaction with methanol, the esterification tower is connected with a methanol preheater, and the output end of the methanol preheater is connected with a membrane dryer; according to the invention, unreacted methanol and generated water in the esterification tower are heated and evaporated out through the methanol preheater, and then are filtered and separated through the membrane dryer, so that water is removed, and the residual methanol flows back to the methanol raw material tank and can be continuously conveyed into the esterification tower for esterification reaction; the problems that an existing continuous esterification method for producing dimethyl adipate is high in energy consumption and production cost is increased are solved.

The invention provides a preparation method of a mixed adipic acid alcohol amide curing agent, and the method comprises the following steps: mixing diethanolamine, ethanolamine and a composite catalyst, and dropwisely adding dimethyl adipate; after the reaction is finished, adding a mixed solvent, then adding a decolorizing agent for decolorizing, and filtering out the decolorizing agent and the composite catalyst; cooling the obtained organic phase, crystallizing, and finally filtering to obtain the mixed adipic acid alcohol amide curing agent. According to the invention, the dimethyl adipate, the diethanolamine and the ethanolamine are used as raw materials to synthesize mixed adipic acid alcohol amide; by adopting the mixed catalyst, the separation and purification process is simple, the reaction time is short, the product yield is high and can reach more than 95%, the product purity is high, the energy consumption is reduced, the environmental pollution is small, the cost is low, and the method is an ideal process for realizing industrial preparation.

The invention belongs to the technical field of catalyst preparation, and concretely relates to a noble metal-free catalyst for ester hydrogenation, and a preparation method thereof. The catalyst canbe well applied to hydrogenation of dimethyl adipate to prepare 1,6-hexanediol. The catalyst has the advantages of low hydrogenation reaction pressure, high space velocity, few side reactions, high selectivity of an ester hydrogenation product, high yield of the product, easiness in achieving continuous production, and no device corrosion when applied to the catalytic hydrogenation of dialkyl adipate to prepare 1,6-hexanediol.

The invention relates to the field of chemical engineering, and particularly discloses a membrane dryer, an intermittent esterification reaction system and a dimethyl adipate preparation method.The membrane dryer comprises a shell and a first cavity, a ceramic membrane tube is arranged in the first cavity, a second cavity is formed in the ceramic membrane tube, a second steam inlet is formed in the outer side of the shell, and a second steam outlet is formed in the outer side of the shell; the ceramic membrane tube is used for conveying a gaseous material to be dried to the first cavity, so that only water molecules are conveyed to the second cavity under the filtration of the ceramic membrane tube; a negative pressure environment is provided for the second cavity, a to-be-dried gaseous material is conveyed into the first cavity through a second steam inlet, only water molecules in the to-be-dried gaseous material are conveyed into the second cavity through filtration of the ceramic membrane tube under the driving of negative pressure power, and then the to-be-dried gaseous material is conveyed out of the membrane dryer. The method can be used for continuing to participate in dimethyl adipate synthesis reaction, and solves the problem that the conversion rate of adipic acid is influenced by water generated in the esterification process in the existing dimethyl adipate production method.

The invention discloses a method for producing dimethyl adipate by continuous esterification of adipic acid. The method comprises the following steps: feeding adipic acid particles into a pre-esterification reactor in a solid form, contacting methanol steam with adipic acid in the pre-esterification reactor to carry out reactions, introducing generated materials into a double-esterification reactor, carrying out reactions, and separating the double-esterification product to obtain dimethyl adipate. The method overcomes the problems that the existing adipic acid cannot be continuously fed, thepre-esterification is discontinuous, and the pre-esterification product is unstable in composition.

The invention discloses an alcohol-based gasoline additive which comprises the following components by weight: 1-3 parts of dimethyl adipate, 0.2-1.5 parts of amyl dicyclohexyl phenol, 0.5-2 parts of oleic acid, 0.005-0.1 part of pentadecafluorooctanoic acid and 0.02-0.15 part of polyisobutene succinimide. The alcohol-based gasoline additive has remarkable effects of preventing rubber swelling and corrosion, can be used for improving the oxidation resistance of alcohol-based gasoline, and has a good industrial application prospect.

The invention discloses a preparation method of bottle-grade bio-based 2, 5-furandicarboxylic acid-based copolyester, and relates to the technical field of polyester preparation. The preparation method comprises the following preparation steps: (1) adding sorbitol, dimethyl adipate and an ionic liquid catalyst into a reactor for transesterification to prepare a reaction solution; (2) adding 2, 5-furandicarboxylate, aliphatic diol, a catalyst, a stabilizer and an antioxidant into a reactor for a primary ester exchange reaction, and then adding the reaction liquid for a secondary ester exchangereaction to prepare an esterification liquid; (3) carrying out a pre-polycondensation reaction on the esterification liquid to obtain a prepolymer; (4) carrying out final polycondensation reaction onthe prepolymer to obtain bottle-grade bio-based 2, 5-furandicarboxylic acid-based copolyester. The dimethyl adipate and sorbitol esterification oligomer is used as a crosslinking center, and a micro-crosslinking structure is constructed in the molecular chain so that the final polycondensation time is greatly shortened, the molecular weight of the copolyester is improved, and the performance of the copolyester is improved.