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A kind of preparation method of 1,4-cyclohexanedimethanol

A technology of cyclohexanedimethanol and cyclohexanedimethanol, which is applied in the field of continuous hydrogenation to prepare 1,4-cyclohexanedimethanol, can solve the problem of reduced selectivity of target products, reduced reaction speed, low concentration of reactants, etc. problems, to achieve the effect of good industrial application prospects, fast hydrogenation rate, and high CHDM yield

Active Publication Date: 2022-08-02
浙江清和新材料科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Due to the limitation of mass transfer resistance, the reactant CHDA cannot quickly diffuse into the pores of the catalyst, resulting in a low concentration of reactants inside the catalyst, which significantly reduces the reaction rate; more importantly, if the CHDM produced by the reaction cannot quickly diffuse from the pores of the catalyst It is very easy to have side reactions such as decarboxylation and esterification, which greatly reduces the selectivity of the target product

Method used

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  • A kind of preparation method of 1,4-cyclohexanedimethanol
  • A kind of preparation method of 1,4-cyclohexanedimethanol

Examples

Experimental program
Comparison scheme
Effect test

Embodiment A1

[0018] Example A1: Weigh a certain mass of stannous chloride, palladium chloride and ruthenium chloride, dissolve with hydrochloric acid, and put a certain amount of carbon nanotubes into the above solution for dipping. Immersion for 24h, drying at 120°C for 4h, using NaBH 4 Catalyst 1 was obtained by reduction, wherein the supported amount of metal Ru was 5.0%, the supported amount of metal Pd was 0.5%, and the supported amount of Sn was 4.0%.

Embodiment A2

[0019] Example A2: the carrier is carbon nanofibers, and the other is the same as Example A1, and catalyst 2 is obtained.

Embodiment B1

[0033] The optimization of the reaction process conditions was carried out in a fixed bed reactor, and 20.0 g of catalyst 1 was filled in a reaction tube with an inner diameter of 13 mm. CHDA is dissolved in a high pressure dissolving kettle to obtain a 20 wt% CHDA aqueous solution, and the CHDA solution is pumped into the fixed bed through a high temperature pump. Catalyst evaluation conditions: reaction temperature 230°C, reaction pressure 8.0MPa, feed mass space velocity of CHDA 0.5h -1, the molar ratio of hydrogen to CHDA is 20.0. The evaluation results are shown in Table 2. The corresponding reaction conditions were changed in Examples B2-B8, and the results are shown in Table 2.

[0034] Table 2

[0035]

[0036] From the comparison of Examples B1 to B3 in Table 2, it can be seen that the reaction temperature of the catalyst hydrogenation is better when the reaction temperature is 230 ° C. When the reaction temperature is as low as 210 ° C, some CHDA does not have ...

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Abstract

The present invention provides a method for preparing 1,4-cyclohexanedimethanol, which comprises preparing 1,4-cyclohexanedimethanol by hydrogenation of 1,4-cyclohexanedimethanol, and the reaction is carried out in a fixed bed It is carried out on the reactor, 1,4-cyclohexanedicarboxylic acid and water are heated and dissolved in the autoclave, transported to the fixed-bed reactor by a high-temperature pump, and hydrogenated under the action of a catalyst to obtain the product 1,4-cyclohexane Dimethanol; the active component of the catalyst is Ru, the auxiliary agents are Pd and Sn, and the carrier is one of carbon nanotubes and carbon nanofibers. The conversion rate of the raw material 1,4-cyclohexanedicarboxylic acid of the present invention reaches more than 99.5%, and the yield of the product 1,4-cyclohexanedimethanol can stably reach more than 98.5%. In addition, the catalyst has a long service life, and the single-pass operation life of the catalyst is more than 2000h, and the method has a good industrial application prospect.

Description

technical field [0001] The invention belongs to the field of fine chemicals, in particular to a method for preparing 1,4-cyclohexanedimethanol by continuous hydrogenation. Background technique [0002] 1,4-Cyclohexanedimethanol (CHDM) is an important raw material for polyester production. Polyethylene terephthalate (PET) resin modified by CHDM copolymerization has a slow crystallization rate and It also has good processing and physical properties, especially the polyester modified with trans-CHDM has high glass transition temperature and softening temperature, good chemical resistance and environmental adaptability, and has a wide range of applications. At present, the main process of industrial production of CHDM is to use dimethyl terephthalate as raw material. First, the benzene ring is hydrogenated to generate dimethyl 1,4-cyclohexanedicarboxylate and dimethyl 1,4-cyclohexanedicarboxylate. The ester is further hydrogenated to produce CHDM. In comparison, the cost of te...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C29/149C07C31/27B01J23/62B01J37/02B01J37/16
CPCC07C29/149B01J23/626B01J37/0201B01J37/16C07C31/276
Inventor 李显明徐铁勇洪俊杰王杰林桂海
Owner 浙江清和新材料科技有限公司