134 results about "Dimethyl succinate" patented technology

The invention relates to a catalyst usable in hydrotreatment processes, which comprises an alumina-based amorphous support, phosphorus, a C1-C4 dialkyl succinate, acetic acid and a hydro-dehydrogenizing function comprising at least one group VIII element and at least one group VIB element, preferably made up of cobalt and molybdenum, a catalyst whose Raman spectrum comprises the most intense bands characteristic of the Keggin heteropolyanions (974 and / or 990 cm−1), C1-C4 dialkyl succinate and acetic acid (896 cm−1). Preferably, the dialkyl succinate concerned is dimethyl succinate and its main band is at 853 cm−1.The invention also relates to the method of preparing said catalyst, wherein a catalytic precursor comprising the group VIB and group VIII elements, in particular the molybdenum-cobalt pair, and phosphorus, introduced by impregnation, then dried at a temperature below 180° C., is impregnated by the C1-C4 dialkyl succinate, the acetic acid and the phosphorus compound, if the latter has not been entirely introduced beforehand, then, after maturation, dried at a temperature below 180° C. prior to being optionally sulfurized.The invention also relates to the use of this catalyst in any hydrotreatment process.

The invention relates to a method of simultaneously producing dimethyl succinate (DMS) and 1, 4-butyl glycol. The method can also be used to simultaneously produce at least one of Tetrahydro furan (THF) and gamma-irradiation butyl lactone (GBL). In the invention, dimethyl maleate (DMM) is used as raw materials and contacts with hydrogen under the condition of gas phase in a low pressure reaction district and a middle pressure reaction district respectively. A low-pressure reactor and a middle-pressure reactor are equipped with a catalyst. DMS products are produced in the low pressure reaction district and 1, 4-butyl glycol products are produced in the middle pressure reaction district. Simultaneously, at least one of the GBL and THF can be produced in the middle pressure reaction district. Purity of DMS can reach over 99.5% without refining through using a gas-liquid separator. In the invention, the method is used in mild condition; heavier component does not need to be circulated; operation is simple; transesterification type polymerization and other side reactions are greatly reduced in a system.

The invention relates to a method for preparing gamma-butyrolactone through catalytic hydrogenation of dimethyl succinate, which belongs to the field of chemical technology. Gamma-butyrolactone is prepared by utilizing the catalytic hydrogenation of multicomponent metallic oxide catalyst through a fixed bed tubular reactor by adopting dimethyl succinate as raw material and carbinol as solvent. The multicomponent metallic oxide catalyst is prepared through a coprecipitation method, the major catalyst comprises 15 to 80 percent (Wt) of copper oxide and 10 to 50 percent (Wt) of zinc oxide, the catalyst accelerator comprises 0 to 10 percent (Wt) of one or a plurality of the oxides of calcium, barium, magnesium, manganese, nickel, molybdenum or cobalt, and a carrier comprises 5 to 30 percent (Wt) of one or a plurality of aluminium oxide, zirconium dioxide and silicon dioxide. When the reaction temperature is 200 to 300 DEG C, the reaction pressure is 2 to 4 MPa, the mol ratio of hydrogen to ester is 100 to 250, and the liquid hourly space velocity is 0.2 to 0.5 h per hour, the conversion rate of dimethyl succinate is larger than 95 percent, and the selectivity of gamma-butyrolactone is larger than 90 percent. The multicomponent metallic oxide catalyst has higher activity and is inexpensive, and both preparation and recovery of the catalyst can not pollute the environment.

The invention relates to the field of high polymer material synthesis and discloses a method for preparing poly(butylene succinate) through a transesterification method. The method comprises the following steps: carrying out esterification reaction on dimethyl succinate, a dihydric alcohol monomer containing 1,4-butanediol and a composite catalyst in a nitrogen atmosphere, wherein the reaction temperature is 110-150 DEG C and the reaction time is 2-3 hours; carrying out condensation polymerization in a vacuum condition, wherein the vacuum degree is 10-300Pa of absolute pressure, the reaction temperature is 150-240 DEG C and the reaction time is 2-3 hours, thereby preparing the poly(butylene succinate). According to the method, on one hand, the problem of high corrosivity of a polymeric monomer in the prior art can be solved, and on the other hand, the problems of multiple byproduct micromolecules and relatively low yield in the prior art can be solved, so that the production cost of the poly(butylene succinate) can be effectively reduced.

The invention relates to a catalyst for use in the synthesis of dimethyl succinate and application thereof, which belong to the field of chemical industry. The catalyst consists of copper, zinc oxide and alumina serving as active ingredients, and the application of the catalyst in synthesizing dimethyl succinate is also disclosed. Meanwhile, the invention also discloses a method for synthesizing the dimethyl succinate. In the method, the dimethyl succinate is prepared by using monomethyl maleinate as raw material and by hydrogenation in the presence of the catalyst of the invention. Compared with a copper-based catalyst prepared by using traditional methods, the catalyst of the invention has the advantages of neater pore distribution, larger specific surface area, and excellent hydrogenation activity and selectivity, and the target product has the advantages of specific selectivity and good thermal stability. By using the new catalyst, the synthesis method of the invention overcomes the problems of high pressure and high cost and the like of the prior art, and has the advantages of simple process and easily controlled conditions and the like. Therefore, the synthesis method has a good industrial application prospect.

A catalyst usable in hydrotreatment processes: an alumina-based amorphous support, phosphorus, a C1-C4 dialkyl succinate, acetic acid and a hydro-dehydrogenizing function of at least one group VIII element and at least one group VIB element, preferably made up of cobalt and molybdenum, a catalyst whose Raman spectrum comprises the most intense bands characteristic of the Keggin heteropolyanions (974 and / or 990 cm−1), C1-C4 dialkyl succinate and acetic acid (896 cm−1). Preferably, the dialkyl succinate concerned is dimethyl succinate and its main band is at 853 cm−1.

Lignin is a unique reproducible aromatic compound source in the nature; the yield is huge, but the structure is complicated, so that the directional depolymerization is difficult; the utilization degree at present is not high. The method for preparing the aromatic compound through catalytic oxidation of lignin has the main step of dissolving the lignin into a sodium hydroxide water solution; the corrosion on equipment is serious; the waste liquid cannot be easily treated; the environment pollution can be easily caused. The invention provides a method of using the special structure and effect relationship of the rare-earth nanometer metal oxide, directly using agricultural stalks as raw materials under the relatively mild conditions, performing catalytic oxidization on the lignin by a one-pot method to obtain high-added-value products of benzenedicarboxylic acid dimethyl ester, dimethyl succinate and the like. After the separation, the benzenedicarboxylic acid dimethyl ester can be usedfor obtaining phthalic acid through hydrolysis reaction, and becomes a raw material for producing PBT and PET. The method has the advantages that the operation is performed in neutral environment such as organic alcohol; no corrosion is caused on the equipment; the equipment production cost is low. Solvents and catalysts can be recovered by a simple method and can be circularly utilized; the massdischarge into the environment is not needed; the green and environmental-friendly effects are achieved.

The invention discloses a preparation method for dimethyl succinylo succinate (DMSS). The method comprises the following steps of: a), esterifying dimethyl succinate; b), synthesizing DMSS, namely after reaction, cooling materials in a water bath to below 60 DEG C, adding methanol, stirring to pulpifying the materials, transferring into a special film pressure device into which high pressure can be introduced, and separating dimethyl succinate liquid out of dimethyl succinylo succinate sodium salt under pressure of 1.0 to 1.2 MPa to obtain a dimethyl succinylo succinate sodium salt solid filter cake; transferring the acidized materials into a vacuum filter and filtering, suction-filtering a mother solution, completely washing the filter cake by using hot water, and drying in a drying box at the temperature of between 90 and 100 DEG C for 18 hours to obtain DMSS. The preparation method is low in investment, main raw materials can be obtained easily, the preparation method is environment-friendly, and the recycling rate is high.

The invention discloses a method for preparing diester succinate by esterifying diammonium succinate, belonging to the field of chemical technology, and particularly discloses a method for preparing the diester succinate product with the purity of more than 99.8% by taking diammonium succinate as a raw material, contacting the raw material with an esterifying agent in a reactor filled with solid acid catalyst to generate dimethyl succinate crude product and finally refining. The method is simple, mild in technological conditions, reasonable in process flow, less in side reaction, high in product purity and good in quality.

The invention discloses a method for preparing dimethyl succinate. The method comprises two reaction processes of esterification and hydrogenation and the reaction processes are as follows: (1) after pre-esterification reaction, maleic anhydride-methanol solution enters a catalytic distillation tower from the upper rectifying section of the tower, methanol enters the tower from the lower stripping section of the catalytic distillation tower, the reaction section is filled with solid acid catalyst, the two material flows perform countercurrent contact on the surface of the catalyst to perform esterification reaction and synthetize dimethyl maleate; and (2) dimethyl maleate and hydrogen are placed in a fixed bed reactor to perform hydrogenation reaction and generate the dimethyl succinate product in the presence of hydrogenation catalyst under a certain reaction condition. The method of the invention has the advantages of high raw material conversion rate and good product selectivity; and the process flow is simple, the energy consumption is low, no pollution can be caused and the scale production of dimethyl succinate can be realized.

The invention relates to a method for preparing 2,5-diparamethylaniline terephthalic acid (DTTA) which is prepared by using dimethyl succinate succinyl (DMSS) and 4-toluidine as raw materials. The method comprises the steps of: 1, mixing materials; 2, raising the temperature for dissolving; 3, carrying out condensation; 4, carrying out hydrolysis oxidizing reaction; 5, carrying out solid-liquid separation; 6, absorbing and removing impurities; 7, carrying out solid-liquid separation; 8, neutralizing and acidizing; 10, washing and dehydrating; 11, drying; and 12, crushing and packaging. The product of the DTTA is obtained by the steps. The invention has the advantages of reasonable process, high purity of products, stable quality, high yield and safe and reliable reaction process.