阅读说明：本技术 一种用于生产羟基乙酸甲酯的催化剂及其制备方法和应用 (Catalyst for producing methyl glycolate and preparation method and application thereof ) 是由 贺俊 骆念军 钱宏义 计扬 于 2018-08-22 设计创作，主要内容包括：本发明涉及一种用于生产羟基乙酸甲酯的催化剂及其制备方法和应用,包括以下重量百分含量的组分：二氧化硅65％-90％；银元素5％-20％；镍元素0.1-5％；镧元素0.01％-5％；金属元素M 0.01％-5％；所述的金属元素M选自钛、铈、钴或锆中的一种,各元素以与氧结合的形式存在。与现有技术相比,本发明制备方法具有工艺简单、制备过程容易控制等特点；经该方法制备的草酸二甲酯加氢催化剂,具有活性高、寿命长、反应操作条件范围宽等特点。(The invention relates to a catalyst for producing methyl glycolate, a preparation method and application thereof, wherein the catalyst comprises the following components in percentage by weight: 65% -90% of silicon dioxide; 5% -20% of silver element; 0.1 to 5 percent of nickel element; 0.01 to 5 percent of lanthanum element; 0.01-5% of metal element M; the metal element M is selected from one of titanium, cerium, cobalt or zirconium, and each element exists in a form combined with oxygen. Compared with the prior art, the preparation method has the characteristics of simple process, easy control of the preparation process and the like; the dimethyl oxalate hydrogenation catalyst prepared by the method has the characteristics of high activity, long service life, wide reaction operating condition range and the like.)

1. A catalyst for producing methyl glycolate is characterized by comprising the following components in percentage by weight:

65% -90% of silicon dioxide;

5% -20% of silver element;

0.1 to 5 percent of nickel element;

0.01 to 5 percent of lanthanum element;

0.01-5% of metal element M;

the metal element M is selected from one of titanium, cerium, cobalt or zirconium, and each element exists in a form combined with oxygen.

2. The catalyst for producing methyl glycolate according to claim 1, wherein the sum of the mass percentages of the lanthanum element and the metal element M is greater than 0.05% and less than 8%.

3. The process according to claim 1 for producing methyl glycolateThe catalyst is characterized in that the silicon dioxide has the average particle size of 0.1-6mm and the BET specific surface area of 200-600m²Per g of porous silica.

4. The catalyst for producing methyl glycolate according to claim 1, wherein said silver element, nickel element, lanthanum element and metal element M are derived from their corresponding nitrates.

5. A process for preparing a catalyst for the production of methyl glycolate according to any one of claims 1 to 4, comprising the steps of:

(1) weighing salt solutions of silver element, nickel element, lanthanum element and metal element M, and preparing a mixed solution with a certain concentration;

(2) weighing a certain amount of silicon dioxide according to the composition requirement of the catalyst;

(3) pouring the silicon dioxide carrier prepared in the step (2) into the mixed solution prepared in the step (1);

(4) putting the silicon dioxide and the mixed solution mixed in the step (3) into an ultrasonic reactor, and treating for 20-60 min;

(5) and (4) standing the solid and the solution reacted in the step (4) at normal temperature for 1-6h, drying and roasting to obtain the product.

6. The preparation method of the catalyst for producing methyl glycolate according to claim 5, wherein the drying temperature in the step (5) is 80-100 ℃, the drying time is 10-24 hours, the calcination temperature is 450-550 ℃, and the calcination time is 2-6 hours.

7. Use of a catalyst as claimed in claim 1 for the production of methyl glycolate, wherein the catalyst is used for the reaction of dimethyl oxalate with a molecular hydrogen-containing gas to produce methyl glycolate.

8. Use of a catalyst for the production of methyl glycolate according to claim 7, wherein the reaction is at a temperature of 180 ℃ and 250 ℃ with a molar ratio of hydrogen to dimethyl oxalate (40-200): 1. the reaction pressure is 2.0-3.5MPa and the space velocity is 0.1-2.0 h-1.

Technical Field

The invention relates to the field of catalysts, and particularly relates to a catalyst for producing methyl glycolate and a preparation method thereof.

Background

Methyl glycolate is the simplest alcohol acid ester and is used as an important chemical raw material intermediate and an excellent solvent, and the methyl glycolate serving as the intermediate has the following purposes: the method has the advantages of preparing ethylene glycol by hydrogenation, preparing glycollic acid by hydrolysis, preparing dimethyl malonate by carbonylation, preparing alanine by ammonolysis and the like, is widely applied to the fields of chemical industry, medicines, dyes and the like, and has wide application prospect.

At present, the main processes for producing methyl glycolate at home and abroad comprise a formaldehyde carbonylation esterification method, a chloroacetic acid hydrolysis method, a formaldehyde and hydrocyanic acid addition method, a methyl formate and formaldehyde coupling method, a methylal and formaldehyde free radical addition method and the like, and the defects of high pollution, high energy consumption, high toxicity, equipment corrosion and the like generally exist, so that no mature process route exists at home at present. At present, the production is carried out by a series of processes such as mixing reaction of chloroacetic acid and caustic soda solution and esterification. The process has the advantages of serious corrosion, heavy pollution, low yield, high cost and high impurity content in the product. Aiming at the defects of high energy consumption, heavy pollution and high cost of the domestic route, an environment-friendly synthesis and process route needs to be developed urgently.

In recent years, a technology for producing Ethylene Glycol (EG) by using coal or natural gas as a raw material has made a significant breakthrough, and particularly, a technological method for preparing ethylene glycol by coupling and synthesizing dimethyl oxalate by using CO and methyl nitrite and then hydrogenating the dimethyl oxalate has been adopted, and a plurality of industrial devices are operated successfully at present. Under the background, the method for preparing the methyl glycolate by using the dimethyl oxalate as the raw material through hydrogenation can fully utilize rich coal and natural gas resources in China and develop C1 chemistry, and is a production route which is economic, environment-friendly and sustainable in development and accords with the national conditions of China.

The research on the production process of preparing methyl glycolate by hydrogenating oxalate is carried out by related scientific research institutes and enterprises in China, and certain progress is made. Chinese patent CN105585483A discloses a method for synthesizing glycolate, wherein the reaction temperature is 150-: 1, the conversion of oxalate reached 100%, the yield of methyl glycolate reached 92%, but there was still room for further improvement in the selectivity of methyl glycolate.

Chinese patent CN105622418A discloses a method and catalyst for preparing methyl glycolate by hydrogenating oxalate, which adopts a catalyst with copper as an active component and a composite oxide of silica as a carrier, and has high selectivity of methyl glycolate but low conversion rate of oxalate.

Chinese patent CN107442113A discloses a multistage Ag catalyst with a nanoflower structure for preparing methyl glycolate by hydrogenating oxalate, wherein the reaction temperature is 180 ℃ and 220 ℃, the reaction pressure is 1-4MPa, the molar hydrogen-ester ratio is 80-120, the mass space velocity of oxalate is 1.5-2h < -1 >, the final conversion rate of oxalate reaches 98.6%, and the selectivity of methyl glycolate is 94.5%. The catalyst has complex preparation, difficult control of the carrier synthesis process, poor repeatability, unsuitability for industrial production and low conversion rate.

Chinese patent CN103372453B discloses a catalyst for synthesizing methyl glycolate and a preparation method thereof, wherein the catalyst is represented as Ag-M/SiO2, wherein SiO2 is a carrier, Ag is a main active component, and M is an auxiliary agent, wherein the mass of Ag accounts for 1-20% of the total mass of the catalyst, and the mass of M accounts for 0.1-5.0% of the total mass of the catalyst. The assistant M is one or more of Mg, Ca, Ti, Zr, V, Nb, Mo, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Au, Zn, Cd, B, Al, C, N, P, La and Ce, but the catalyst mentioned in the patent has a complex preparation method and is not easy to industrialize; the selectivity of methyl glycolate is to be improved. Although this patent discloses that the catalyst may be supplemented with an auxiliary, the listed optional auxiliaries do not work well in every case, and in fact the kind and amount of auxiliary affects the catalyst very greatly.

According to the reported technology at present, the synthesis of the methyl glycolate by oxalate hydrogenation basically adopts Cu and Ag catalysts, in the actual preparation and application processes, the active components of the catalysts are not uniformly distributed, and Cu and Ag particles are sintered along with the extension of the reaction time, so that the particles grow up, and the conversion rate and the selectivity of the reaction are reduced.

Disclosure of Invention

The present invention aims at overcoming the defects of the prior art and providing a catalyst for producing methyl glycolate, a preparation method and an application thereof, wherein the catalyst has the advantages of high activity, high selectivity, simple catalyst preparation and low cost.

The purpose of the invention can be realized by the following technical scheme: a catalyst for producing methyl glycolate is characterized by comprising the following components in percentage by weight:

65% -90% of silicon dioxide;

5% -20% of silver element;

0.1 to 5 percent of nickel element;

0.01 to 5 percent of lanthanum element;

0.01-5% of metal element M;

the metal element M is selected from one of titanium, cerium, cobalt or zirconium, and each element exists in a form combined with oxygen.

The sum of the mass percent of the lanthanum element and the mass percent of the metal element M is more than 0.05 percent and less than 8 percent.

The silicon dioxide has the average particle size of 0.1-6mm and the BET specific surface area of 200-600m²Per g of porous silica.

The silver element, the nickel element, the lanthanum element and the metal element M are derived from corresponding nitrates.

A method for preparing a catalyst for the production of methyl glycolate, comprising the steps of:

(1) weighing salt solutions of silver element, nickel element, lanthanum element and metal element M, and preparing a mixed solution with a certain concentration;

(2) weighing a certain amount of silicon dioxide according to the composition requirement of the catalyst;

(3) pouring the silicon dioxide carrier prepared in the step (2) into the mixed solution prepared in the step (1);

(4) putting the silicon dioxide and the mixed solution mixed in the step (3) into an ultrasonic reactor, and treating for 20-60 min;

(5) and (4) standing the solid and the solution reacted in the step (4) at normal temperature for 1-6h, drying and roasting to obtain the product.

The drying temperature in the step (5) is 80-100 ℃, the drying time is 10-24 hours, the roasting temperature is 450-550 ℃, and the roasting time is 2-6 hours.

The application of the catalyst for producing the methyl glycolate is characterized in that the catalyst is used for reacting dimethyl oxalate with gas containing molecular hydrogen to generate the methyl glycolate.

The reaction is carried out at the temperature of 180 ℃ and 250 ℃ and the molar ratio of hydrogen to dimethyl oxalate (40-200): 1. the reaction pressure is 2.0-3.5MPa and the space velocity is 0.1-2.0 h-1.

Compared with the prior art, the invention can obviously increase the dispersion degree of each element by carrying out ultrasonic reaction on the mixed silicon dioxide and the solution, and each element is more uniformly loaded on the catalyst. The addition of lanthanum and zirconium can obviously improve the aggregation of silver elements on the catalyst and the thermal stability of the catalyst, and the addition of lanthanum also causes the problems that the surface active sites of the catalyst are obviously increased when not added and silver particles are continuously increased in the later use process. Therefore, the catalyst is applied to the production of methyl glycolate by hydrogenation of oxalate, has better activity and methyl glycolate selectivity and better thermal stability than the existing catalyst, and has simpler preparation method and lower cost.

Detailed Description

The following examples are given for the detailed implementation and specific operation of the present invention, but the scope of the present invention is not limited to the following examples.