CN108607553B

CN108607553B - Catalyst for preparing 1, 3-propylene glycol by glycerol hydrogenolysis, preparation and application thereof

Info

Publication number: CN108607553B
Application number: CN201611127797.7A
Authority: CN
Inventors: 王爱琴; 杨曼; 赵晓晨; 张涛; 孙永南
Original assignee: Dalian Institute of Chemical Physics of CAS
Current assignee: Zhongke Baiyijin Zhengzhou New Energy Technology Co ltd
Priority date: 2016-12-09
Filing date: 2016-12-09
Publication date: 2021-06-01
Anticipated expiration: 2036-12-09
Also published as: CN108607553A

Abstract

The patent relates to a catalyst for preparing 1, 3-propylene glycol by glycerol hydrogenolysis and a preparation method thereof, wherein the catalyst is composed of a tungsten oxide carrier doped with transition metals such as Nb and Ta and loaded with active components such as Pt, Pd or auxiliary metals. The preparation method of the catalyst comprises the following steps: a) preparing catalyst carrier Nb, Ta and other transition metal doped tungsten oxide by a hydrothermal method or a solvothermal method; b) and (3) impregnating the catalyst carrier with a precursor solution of Pt, Pd or the auxiliary metal, drying and reducing to obtain the Pt, Pd or auxiliary metal/transition metal doped tungsten oxide catalyst. The catalyst prepared by the patent can ensure that the glycerin aqueous solution is subjected to hydrogenolysis to generate the 1, 3-propanediol with high selectivity in a larger hydrogen pressure range and a larger temperature range.

Description

Catalyst for preparing 1, 3-propylene glycol by glycerol hydrogenolysis, preparation and application thereof

The invention relates to a catalyst for preparing 1, 3-propanediol by hydrogenolysis of glycerol; the method specifically comprises the steps of preparing a transition metal doped tungsten oxide carrier by a hydrothermal or solvothermal method, and carrying active noble metal components by an impregnation method to obtain the high-dispersion noble metal carrying catalyst.

Technical Field

With the rapid development of biodiesel, a large amount of glycerol, which is a byproduct in the biodiesel production process, is in excess, and the conversion of glycerol to prepare high-value chemicals becomes an effective means for improving the economic efficiency of the biodiesel industry. Glycerol can be converted to 1, 3-propanediol, 1, 2-propanediol, and the like by hydrogenolysis reactions, wherein 1, 3-propanediol is an important monomer for the production of polytrimethylene terephthalate (PTT). PTT is a novel polyester fiber with biodegradability, overcomes the defects that polyethylene terephthalate (PET) is too hard and polybutylene terephthalate (PBT) is too soft, has excellent rebound resilience, easy dyeing property, biodegradability and the like, and has huge development potential in the industries of carpets, textile engineering plastics and the like.

Currently, the commercial processes for the production of 1, 3-propanediol include the ethylene oxide carbonylation hydrogenation process from Shell and the acrolein hydration hydrogenation process from Degussa and Dupont. The ethylene oxide carbonylation hydrogenation method (Chinese patent CN1201407A) adopts a method that ethylene oxide and synthesis gas generate 3-hydroxypropionaldehyde under the action of a cobalt-based catalyst, and then the 3-hydroxypropionaldehyde and hydrogen are hydrogenated under the action of a hydrogenation catalyst to generate 1, 3-propylene glycol. The acrolein hydration method (Chinese patent CN93114516.3) adopts gas glycerol hydrate to dehydrate under the action of a solid acid catalyst to generate acrolein, the generated acrolein is hydrated under the action of an acid catalyst to generate 3-hydroxypropionaldehyde, the generated 3-hydroxypropionaldehyde is hydrogenated under a conventional hydrogenation catalyst to prepare 1, 3-propylene glycol, and meanwhile, the 1, 2-propylene glycol is a byproduct. The industrial production process is complex and has serious environmental pollution, and the obtained 1, 3-propylene glycol contains impurities and needs further purification treatment.

The literature (appl. Microbiol. Biotechnol.1992,36,592-597) reports a process for preparing 1, 3-propanediol by bioconversion of the strain Clostridium species, in which a 110g/L glycerol solution can be converted after 29h to 56 g/L1, 3-propanediol, which is affected by the activity of the biological metabolism, is less efficient and requires a high energy consumption for the purification and isolation of 1, 3-propanediol due to the low product concentration. The literature (Catal. Commun.2008,9, 1360-. The reaction adopts an organic solvent as a reaction medium, and the adopted method of adding liquid acid does not meet the requirement of green chemistry.

The direct hydrogenolysis of glycerol to 1, 3-propanediol has received considerable attention in recent years because of its simple process and inexpensive raw materials. However, the reaction for preparing 1, 3-propanediol by direct hydrogenolysis of glycerol coexists in series and parallel, 1, 3-propanediol is used as an intermediate product, the generation of the 1, 3-propanediol is firstly to remove hydroxyl from glycerol to generate carbenium ion, the carbenium ion generated by removing the intermediate hydroxyl is more stable and is kinetic priority, the subsequent hydroxypropionaldehyde generated is thermodynamically unstable, and the mutual competition between the two is also the key for generating 1, 3. The mechanism of 1, 3-propanediol production makes efficient production of 1, 3-propanediol a great challenge.

Disclosure of Invention

Compared with the prior art, the catalyst for preparing the 1, 3-propanediol by directly hydrogenolyzing the glycerol and the preparation method thereof have good selectivity of the 1, 3-propanediol and effectively reduce the generation of the 1, 2-propanediol under a very wide reaction condition window.

The invention provides a catalyst for preparing 1, 3-propylene glycol by glycerol hydrogenolysis, wherein a catalyst carrier is Nb or/and Ta doped tungsten oxide synthesized by a hydrothermal or solvothermal method, and the mass content of doped metal is 0.01-30% of the weight of W; the active component is platinum group metal Pt or/and Pd, and the mass content of the active component is 0.01-10% of the weight of the catalyst.

The preparation method of the Nb-and/or Ta-doped tungsten oxide carrier of the catalyst comprises the following steps:

dissolving precursors of tungsten and niobium or/and tantalum in a solvent according to a ratio (1: 0.0001-0.3), transferring the solution into a hydrothermal kettle with a lining after the precursors are completely dissolved, placing the hydrothermal kettle in a preheated oven at 40-200 ℃ for 6h-1 week, naturally cooling to room temperature, performing suction filtration, washing with absolute ethyl alcohol and deionized water for several times, and then conventionally drying, freeze drying or vacuum drying the carrier Nb or/and Ta doped tungsten oxide.

The catalyst is prepared by an impregnation method. Soaking Nb or/and Ta doped tungsten oxide carrier loaded with active components Pt or/and Pd with chloroplatinic acid or/and chloropalladite solution, drying by conventional method, freeze drying or vacuum drying, and performing H-drying at 600 deg.C under 100-₂Reducing to obtain the catalyst.

The catalyst is applied to the reaction for preparing the 1, 3-propanediol by hydrogenolysis of the glycerol aqueous solution, and the reaction conditions are as follows: the reaction is carried out in a batch kettle type reactor, the mass concentration of the glycerol aqueous solution is 1-99.9%, the reaction temperature is 100-300 ℃, preferably 110-200 ℃, and the reaction time of the glycerol and the catalyst is 0.5-50 hours, preferably 6-24 hours.

Compared with the prior art, the method can improve the selectivity of preparing the 1, 3-propylene glycol by hydrogenolysis of the glycerol, improve the conversion rate of the glycerol, effectively inhibit the generation of the 1, 2-propylene glycol, widen the reaction pressure window and improve the stability.

Drawings

Figure 1 morphology of support Nb-tungsten oxide: a, c are 0.1 percent of Nb-tungsten oxide carrier morphology; b and d are 2 percent of Nb-tungsten oxide carrier morphology.

Detailed Description

EXAMPLE 1 preparation of Nb-tungsten oxide support

The method adopts a solvothermal method to prepare the Nb-tungsten oxide (Nb: W is 0.1 percent, 2 percent and 5 percent) carrier, and comprises the following specific preparation steps: mixing WCl₆And NbCl₅(1: 0.001-0.1) dissolving in absolute ethyl alcohol until WCl is obtained₆And NbCl₅And after complete dissolution, quickly transferring the yellow transparent solution into a hydrothermal kettle with a lining, placing the hydrothermal kettle in a preheated oven at 160 ℃ for 6-36h (24 h), naturally cooling to room temperature, washing with absolute ethyl alcohol and deionized water for 3 times, and then placing the hydrothermal kettle in a vacuum drying oven at 50 ℃ for drying to obtain the carrier Nb-tungsten oxide. The appearance is shown in figure 1.

Example 2 preparation of the catalyst

Soaking chloroplatinic acid solution onto the Nb-tungsten oxide carrier in the same volume, drying in the shade at room temperature, wherein the Pt loading amount is 2%, and after drying in a 50 ℃ oven in vacuum for 6h, activating with hydrogen under the activation condition of 300 ℃, the hydrogen flow rate of 60ml/min and the activation time of 1h, preparing the 2% Pt/Nb-tungsten oxide catalyst.

Example 3 testing of catalyst Performance

An intermittent reaction kettle is selected, the mass concentration of the glycerol aqueous solution is 5% (12 g of the solution), the catalyst amount is 0.3g (the mass ratio of the catalyst to the glycerol is 1:2), the reaction temperature is 160 ℃, the reaction pressure is 1MPa, and the reaction time is 12 h. The test results are shown in Table 1.

Example 4 testing of catalyst Performance

An intermittent reaction kettle is selected, the mass concentration of the glycerol aqueous solution is 5% (12 g of the solution), the catalyst amount is 0.3g (the mass ratio of the catalyst to the glycerol is 1:2), the reaction temperature is 160 ℃, the reaction pressure is 5MPa, and the reaction time is 12 h. The test results are shown in Table 1.

TABLE 1 catalytic Properties of the hydrogenolysis of glycerol to 1, 3-propanediol

Others include small amounts of methane, ethane, propane, methanol, ethanol, ethylene glycol, acetone, hydroxyacetone, overall material conservation.

Claims

1. A catalyst for preparing 1, 3-propylene glycol by hydrogenolysis of glycerol is characterized in that: the catalyst carrier is a tungsten oxide material doped with transition metal, and the active component is platinum group metal or platinum group metal and an auxiliary agent thereof; the auxiliary agent is one or more of Mo, Au, Fe, La and Al, and the weight of the auxiliary agent is 0.01-0.5% of the weight of the platinum group metal;

the transition metal doped tungsten oxide is prepared by a hydrothermal method or a solvothermal method;

dissolving precursors of tungsten, niobium or/and tantalum in a solvent, transferring the solution into a kettle with a lining after the precursors are completely dissolved, placing the kettle in a preheated oven at 40-200 ℃ for 6h-1 week, naturally cooling to room temperature, performing suction filtration, washing with absolute ethyl alcohol and deionized water for 2-8 times, and drying to obtain a carrier Nb or/and Ta doped tungsten oxide;

the doping amount of the transition metal is 0.01-30% of the weight of W, the platinum group metal is Pt or/and Pd, and the content of the platinum group metal is 0.01-10% of the weight of the catalyst.

2. The catalyst of claim 1, wherein: the doped transition metal is Nb or/and Ta.

3. The catalyst of claim 1, wherein:

the solvent is one or more of water, ethanol, n-propanol, isopropanol, and acetone.

4. The catalyst of claim 3, wherein: the drying method is conventional drying, freeze drying or vacuum drying.

5. A process for preparing a catalyst as claimed in any one of claims 1 to 4, characterized in that: the loading method of the catalyst active noble metal is an isometric impregnation method, an excess impregnation method, a vacuum impregnation method or an ion exchange method.

6. The method for preparing the catalyst according to claim 5, wherein: the reduction temperature of the catalyst is 100-600 ℃; the selected platinum group metal is Pt or/and Pd, the precious metal precursor is chloroplatinic acid and chloropalladic acid, and the molar concentration of the solution is 0.05-5M.

7. Use of a catalyst according to any one of claims 1 to 4, wherein: the catalyst is used in the reaction of preparing 1, 3-propanediol by hydrogenolysis of glycerol, the reaction raw material is glycerol aqueous solution, and the mass concentration range is 1-99.9%.

8. Use of a catalyst according to claim 7, characterized in that: the hydrogen pressure is 0.1-10MPa, and the reaction temperature is 100-300 ℃.