TWI395729B - A method for producing a dihydric alcohol compound - Google Patents

Description

Method for producing glycol compounds

The present invention relates to a process for producing a glycol compound which is subjected to a hydrogenation reaction under the conditions of a specific temperature and pressure in the presence of a catalyst to produce a glycol compound. More particularly, the invention relates to a process for the manufacture of 1,4-butanediol from 4-hydroxybutanal.

1,4-Butanediol (BDO) is an important organic chemical raw material for the production of tetrahydrofuran (THF), γ-butyrolactone (GBL) and polybutylene terephthalate. Tetrahydrofuran and γ-butyrolactone are widely used as solvents in pharmaceutical, chemical, textile, ink, paper, automotive, electroplating and other industries. Polytetramethylene glycol ether (PTMG) produced from tetrahydrofuran can be used to synthesize high performance polyurethane resin (PU) and elastic fiber spandex. Gamma-butyrolactone can be used to synthesize 2-pyrrolidone and methylpyrrolidone and intermediates of vitamin B12. The reaction of 1,4-butanediol with terephthalic acid produces dibutyl terephthalate (PBT), an engineering plastic with excellent properties and is widely used in the automotive, machinery, electronics and electrical industries. Since 1,4-butanediol has a wide range of uses and has great market prospects, it has attracted more and more attention.

At present, 1,4-butanediol can be produced by hydrogenation of 4-hydroxybutanal, and most of the catalysts for hydrogenation are metal-supported catalysts, such as ruthenium, palladium, and nickel supported on metal oxides. , ruthenium, cobalt, platinum, are common hydrogenation catalysts. Among them, a supported hydrogenation activity is exhibited by a supported nickel and ruthenium catalyst or a Raney Nickel catalyst [US 5,426,250]. In recent years, there have been reports in the literature on polymer-stabilized nano-metal cluster catalysts, such as noble metals such as platinum, palladium, rhodium, etc., in hydrogenation reactions such as selective hydrogenation of olefins, selective hydrogenation of diketones, and selection of unsaturated aldehydes. Hydrogenation, selective hydrogenation of methyl acrylate, etc., have superior activity and selectivity [Chem. Rev. 92 (1992) 1709] [Appl. Catal., A: Chem. 144 (1999) 123].

The metal nano-clusters supported on the carrier are the main reactive sites, which are composed of a specific number of atoms, close to a single dispersed and ordered structure of metal nanoparticles, which is different from the bulk metal. Unique chemical and physical properties with a single metal atom. Techniques for preparing metal nanoclusters or metal nanocolloidal particles include chemical reduction, electrochemical reduction, vapor deposition, microwave irradiation, UV photolysis, thermal decomposition, and the like. Among them, the chemical reduction method [J. Am. Chem. Soc., 93 (1971) 1301] has been widely used in catalytic applications because of its advantages of easy preparation, stable dispersion, small particle size, and narrow distribution. In industrial production, the catalyst must have good reproducibility. Therefore, it is often loaded on a heterogeneous support during the preparation process, or a polymer, a surfactant, a ligand is added as a stabilizer, and dispersed in a solvent. It is preserved and used to avoid the growth of nanoparticle aggregates [J. Mol. Catal. A, 177 (2001) 113.].

Increasing the catalytic activity of the hydrogenation catalyst, increasing the stability and prolonging the reaction life are the key points for the research and development of the hydrogenation catalyst. The invention provides a preparation method of a core-shell hydrogenation catalyst with high stability, high dispersibility and high activity, and uniformly coats the surface of the metal active site with one or more layers of nanometer by using nano-particle engineering. Grade shell. By such a core-shell structure, the electrical properties, functionality, activity, and the like of the surface of the center particle are changed to have good dispersibility and stability. In addition, by protecting the outer casing, the central metal is reduced from external chemical or physical influences to prolong the reaction life and utilize the generated pores to increase the reaction selectivity.

One of the objects of the present invention is to provide a method for preparing a core-shell hydrogenation catalyst having high stability, high dispersibility and high activity.

Another object of the present invention is to provide a process for the preparation of a core-shell hydrogenation catalyst which can be used for the hydrogenation of aldehyde compounds.

Still another object of the present invention is to provide a process for producing a glycol compound which is produced by hydrogenation of an aldehyde compound at a specific temperature and pressure in the presence of a core-shell hydrogenation catalyst, in particular, to produce a glycol Class of compounds.

The preparation of core-shell type nanoparticles, in addition to combining versatility, may also result in new properties. In general, the objectives can be divided into four major items: one, modifying the bulk properties of the nanoparticle, or producing new properties different from the original component; 2. adjusting the surface properties of the nanoparticle to change its surface charge density. , functionality, reactivity, biocompatibility, stability and dispersibility; third, using core particles as a plate mold to prepare hollow spherical shells; Fourth, to create multifunctional nano-particles.

In the core-shell type of nanoparticle preparation process, the most common preparation method is completed in two steps except for the difference in reaction, nucleation, and excessive growth rate of each component. That is, the core particles required are synthesized by a general single-component nanoparticle synthesis method, and the nanoshell layer is further produced by a coating technique.

In the present invention, a diol compound is produced by hydrogenation reaction of an aldehyde compound in the presence of a catalyst. In particular, the present invention produces a glycol compound from an aldehyde compound in the presence of a core-shell catalyst, wherein the core-shell catalyst is:

M@SiO ₂

Wherein M represents an active metal.

According to a specific embodiment of the present invention, 1,4-butanediol is produced from 4-hydroxybutanal in the presence of a core-shell catalyst.

In the present invention, the amount of catalyst added is in the range of 0.1 to 5% by weight, preferably 0.4 to 2% by weight, based on the total weight of the reaction liquid; the reaction temperature is between 80 and 150 ° C, preferably between Between 90 and 130 ° C; the reaction pressure is between 200 and 1500 psig, preferably between 400 and 1300 psig.

The core-shell catalyst used in the present invention has properties related to the preparation conditions, and when used in the aldehyde hydrogenation reaction, the reaction yield is related to the type and amount of the active metal used, the reaction temperature, the pressure, and the like.

The invention can be applied to batch process and continuous process, including Continuous Stirred Tank Reactor (CSTR), Packed Bed Reactor, Fluidized Bed Reactor and the like.

The features and effects of the present invention are further illustrated by the following examples, which are not intended to limit the scope of the invention.

The Turnover Frequency (TOF) described in this specification is calculated according to the following equation:

TOF(1/s)=[addition amount of aldehyde compound-residual amount of aldehyde compound after reaction] (mol) / amount of active metal added (mol) / reaction time (sec)

(Comparative Example 1) (1) Hydrogenation reaction test

50 ml of 4-hydroxybutanal reaction solution and 0.2 g of Raney nickel catalyst were placed in a hydrogenation reactor, the reaction temperature was controlled at 95 ° C, and the pressure was set to 400 psig with hydrogen. Samples were taken at a reaction time of 0.5 hours, and the samples were analyzed by gas chromatography. The results are shown in Table 1.

(Example 1) (1) Catalyst preparation

Dissolve 0.0626 g of cerium chloride salt in 3 ml of deionized water, then gradually add the polymer stabilizer and reducing agent, stir evenly in an alkaline environment, dissolve it, then wash it with acetone, and take out the black colloid solution. After drying, after drying, it is uniformly dissolved with 0.998 ml of deionized water, 0.339 ml of ammonia water and 6.643 ml of ethanol, and then the template is added, stirred for 24 hours, the black colloidal solution is taken out and dried, and after drying, in an air atmosphere. Calcination for several hours and calcination in a mixed atmosphere of argon and hydrogen for 3-5 hours gives the desired Ru@SiO ₂ catalyst.

(2) Hydrogenation reaction test

50 ml of 4-hydroxybutanal reaction solution and 0.2 g of Ru@SiO ₂ catalyst were placed in a hydrogenation reactor, the reaction temperature was controlled at 95 ° C, and hydrogen pressure was applied to 400 psig. Samples were taken at a reaction time of 0.5 hours, and the samples were analyzed by gas chromatography. The results are shown in Table 1.

(Example 2-5) (1) Catalyst preparation

The ruthenium chloride salt of Example 1 was replaced with another metal salt, and the desired catalyst was prepared by the same catalyst preparation method as in Example 1.

(2) Hydrogenation reaction test

The same hydrogenation reaction test method as in Example 1 was carried out, and the catalysts were changed to Rh@SiO ₂ , Pd@SiO ₂ , Pt@SiO ₂ and Ni@SiO ₂ , respectively, and the results are shown in Table 1.

It can be seen from the experimental results in Table 1 that the core-shell catalyst invented in the experiment can effectively carry out the hydrogenation of 4-hydroxybutyraldehyde to prepare 1,4-butanediol, and has better catalytic activity than commercial catalyst Reynolds nickel. Among them, Ru@SiO ₂ and Pd@SiO ₂ have better reactivity.

(Examples 6-7) (1) Catalyst preparation

The catalyst was prepared in the same manner as in Example 1 to prepare the desired catalyst.

(2) Hydrogenation reaction test

50 ml of 4-hydroxybutanal reaction solution and 0.2 g of Ru@SiO ₂ catalyst were placed in a hydrogenation reactor, and the reaction temperature was controlled to 95 ° C, and hydrogen gas was respectively pressurized to 800 and 1000 psig. Samples were taken at a reaction time of 0.5 hours, and the samples were analyzed by gas chromatography, and the results are shown in Table 2.

It can be seen from the experimental results in Table 2 that as the reaction pressure increases, the hydrogenation activity of Ru@SiO ₂ also increases.

(Examples 8-9) (1) Catalyst preparation

The catalyst was prepared in the same manner as in Example 1 to prepare the desired catalyst.

(2) Hydrogenation reaction test

50 ml of 4-hydroxybutanal reaction solution and 0.2 g of Ru@SiO ₂ catalyst were placed in a hydrogenation reactor, and the reaction temperatures were controlled at 95, 110, and 120 ° C, respectively, and hydrogen was pressurized to 400 psig. Samples were taken at a reaction time of 0.5 hours, and the samples were analyzed by gas chromatography, and the results are shown in Table 3.

It can be seen from the experimental results in Table 3 that as the reaction temperature increases, the hydrogenation activity of Ru@SiO ₂ also increases.

Claims (5)

A method for producing a glycol, which is produced by hydrogenating an aldehyde compound in the presence of a catalyst at a temperature ranging from 80 to 150 ° C and a pressure ranging from 200 to 1500 psig. A glycol compound, wherein the catalyst is a core-shell metal catalyst represented by the following experimental formula: M@SiO ₂ wherein M represents an active metal. The manufacturing method of claim 1, wherein the active metal M is selected from the group consisting of metals of Group VIIIB and mixtures thereof. The manufacturing method of claim 2, wherein the active metal M is selected from the group consisting of ruthenium, rhodium, palladium, platinum, nickel, and mixtures thereof. The production method of claim 1, wherein the reaction is carried out at a temperature ranging from 90 to 130 °C. The manufacturing method of claim 1, wherein the reaction is carried out at a pressure in the range of from 400 to 1300 psig.