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CN-122006722-A - Catalyst for alcoholysis of glycollic acid oligomer and application thereof

CN122006722ACN 122006722 ACN122006722 ACN 122006722ACN-122006722-A

Abstract

The invention relates to the field of chemical waste treatment, and discloses a catalyst for alcoholysis of an glycollic acid oligomer and application thereof. The catalyst comprises 20-70 wt% of zinc oxide, 10-35 wt% of cadmium oxide, 10-35 wt% of aluminum oxide and 0.1-15 wt% of cerium oxide based on the total weight of the catalyst. The catalyst has good performance of treating the glycollic acid oligomer, and the preferable implementation mode of the catalyst is beneficial to realizing continuous production of glycollic acid esters and glycol by the oligomer, reduces the production flow, overcomes the defect that the traditional batch kettle is not beneficial to enlarging the productivity, and has important significance for realizing large-scale industrial application.

Inventors

  • ZHU YUEHUI
  • ZHAO KAIJING
  • GAO JIDONG
  • SHI QIAN
  • LU SHULIANG

Assignees

  • 中国石油化工股份有限公司
  • 中石化(北京)化工研究院有限公司

Dates

Publication Date
20260512
Application Date
20241112

Claims (10)

  1. 1. A catalyst for alcoholysis of an glycolic acid oligomer is characterized in that the catalyst comprises 20-70 wt% of zinc oxide, 10-35 wt% of cadmium oxide, 10-35 wt% of aluminum oxide and 0.1-15 wt% of cerium oxide based on the total weight of the catalyst.
  2. 2. The catalyst of claim 1, wherein the catalyst comprises 30-60 wt.% zinc oxide, 15-30 wt.% cadmium oxide, 15-30 wt.% aluminum oxide, and 1-10 wt.% cerium oxide, based on the total weight of the catalyst.
  3. 3. The catalyst of claim 1, wherein the catalyst has an average particle size of 5-500nm.
  4. 4. A process for producing glycolic acid esters from an glycolic acid oligomer, comprising contacting a starting material of an glycolic acid oligomer with a lower alcohol in the presence of a catalyst; wherein the catalyst is the catalyst of any one of claims 1 to 3.
  5. 5. The method of claim 4, wherein the starting material for the glycollic acid-based oligomer is a fusel oil containing a glycollic acid-based oligomer; Preferably, the fusel oil containing the glycollic acid oligomer comprises at least one of glycol, glycollic acid and glycollate, and an oligomer formed by the polymerization reaction of at least one of glycol, glycollic acid and glycollate; preferably, the weight average molecular weight of the oligomer is 200-5000g/mol.
  6. 6. The method according to claim 5, wherein the content of the oligomer in the starting material of the glycolic acid-based oligomer is 5wt% or more, preferably 10 to 80wt%; Preferably, the content of the glycol in the raw material of the glycollic acid oligomer is 15-80wt%, the content of the glycollic acid is 0-30wt%, and the content of the glycollic acid ester is 0-10wt%.
  7. 7. The process according to claim 4, wherein the weight ratio of the starting material of the glycollic acid-based oligomer to the lower alcohol is from 1:0.5 to 28, preferably from 1:1 to 7, the weight of the starting material of the glycollic acid-based oligomer being based on the weight of the glycollic acid-based oligomer; And/or the lower alcohol is at least one of C1-C5 alcohols, preferably methanol.
  8. 8. The process according to claim 4, wherein the catalyst is packed in a fixed bed or a reaction kettle of continuous feed and the liquid hourly space velocity of the mixture of the starting material of the glycolic acid-based oligomer and the lower alcohol is 0.05-5h -1 , preferably 0.2-2h -1 .
  9. 9. The process according to claim 4, wherein the contacting conditions comprise a temperature of 80-200 ℃, a pressure of 0.1-6MPa, and a time of 10-120min; preferably, the contacting conditions include a temperature of 110-170 ℃, a pressure of 1-3MPa, and a time of 15-60min; And/or the contacting is performed in a continuous feed apparatus comprising a continuous feed fixed bed or a continuous stirred tank reactor, preferably a continuous feed fixed bed.
  10. 10. Use of a catalyst according to any one of claims 1-3 in the alcoholysis of an glycolic acid-based oligomer.

Description

Catalyst for alcoholysis of glycollic acid oligomer and application thereof Technical Field The invention relates to the field of chemical waste treatment, in particular to a catalyst for alcoholysis of an glycollic acid oligomer and application thereof. Background Plastics, synthetic rubbers and synthetic fibers are known as modern trimodal materials. With the development of social economy, the use of plastic products brings great convenience to the daily life and production of human beings, and becomes an essential important material for daily life. Polyglycolide (PGA), also known as polyglycolic acid, is a high-crystalline, biodegradable aliphatic polymer, has the advantages of high degradation speed and the like, and is mainly used in the fields of medical consumables, mulching films and the like. At present, the production process of Methyl Glycolate (MG) in domestic industry mainly comprises a chloroacetic acid hydrolysis method and a formaldehyde molecule carbonylation reesterification method, and the process of the route is complex, the flow is long, the cost is high, the environmental pollution is serious, and the yield of target products is low. Thus, dimethyl oxalate (DMO) is prepared from coal-based synthesis gas, methyl glycolate is prepared by hydrogenation of dimethyl oxalate, and polyglycolic acid (PGA) is further produced, but the route can generate a large amount of glycolic acid esters oligomerization byproducts in the production process, and if the byproducts can be fully recovered, considerable economic benefits can be brought. Therefore, the development of a catalyst capable of efficiently treating oligomers in fusel oil as a byproduct of PGA process and a method for recovering glycolates has important significance. Disclosure of Invention The invention aims to overcome the problems in the prior art and provide a catalyst for alcoholysis of an glycollic acid oligomer and application thereof. In order to achieve the above object, the present invention provides a catalyst for alcoholysis of an glycolic acid oligomer, comprising 20 to 70 wt% of zinc oxide, 10 to 35 wt% of cadmium oxide, 10 to 35 wt% of aluminum oxide and 0.1 to 15 wt% of cerium oxide, based on the total weight of the catalyst. In a second aspect, the invention provides a method for preparing glycolates from glycolates oligomers, which comprises contacting a raw material of glycolates oligomers with a lower alcohol in the presence of a catalyst, wherein the catalyst is provided in the first aspect. In a third aspect the invention provides the use of the catalyst described above in the alcoholysis of an glycolic acid-based oligomer. The catalyst has good performance of treating the glycollic acid oligomer, and the adoption of the preferred embodiment of the invention is beneficial to realizing the continuous production of glycollic acid esters and glycol by the oligomer, reduces the production flow, overcomes the defect that the traditional batch kettle is not beneficial to enlarging the productivity, and has important significance for realizing large-scale industrial application. Detailed Description The endpoints and any values of the ranges disclosed herein are not limited to the precise range or value, and are understood to encompass values approaching those ranges or values. For numerical ranges, one or more new numerical ranges may be found between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, in combination with each other, and are to be considered as specifically disclosed herein. In a first aspect, the invention provides a catalyst for alcoholysis of an ethanoic acid oligomer, the catalyst comprising, based on the total weight of the catalyst, 20 to 70 wt% of an oxide of zinc, 10 to 35 wt% of an oxide of cadmium, 10 to 35 wt% of an oxide of aluminum, and 0.1 to 15 wt% of an oxide of cerium. According to the invention, the catalyst preferably comprises 30-60 wt.% zinc oxide, based on the total weight of the catalyst. According to the invention, the catalyst preferably comprises 15-30 wt.% of oxides of cadmium, based on the total weight of the catalyst. According to the invention, the catalyst preferably comprises 15-30 wt.% of aluminium oxide, based on the total weight of the catalyst. According to the invention, the catalyst preferably comprises 1-10 wt.% cerium oxide, based on the total weight of the catalyst. In the invention, the types and the contents of the catalyst are in the above ranges, so that the overall performance of the catalyst can be further ensured. According to the invention, the catalyst preferably has an average particle size of from 5 to 500nm. In the present invention, the preparation method of the catalyst may be a catalyst preparation method conventional in the art, and preferably, the preparation method of the catalyst includes mixing the precursor of the metal and/or the oxide of the metal (preferably