Search

CN-122010723-A - Method for catalytic degradation of glycolate oligomers

CN122010723ACN 122010723 ACN122010723 ACN 122010723ACN-122010723-A

Abstract

The invention relates to chemical waste treatment and discloses a method for catalytically degrading glycolate oligomer, which comprises the step of contacting a glycolate oligomer-containing raw material with low-carbon alcohol to react in the presence of a catalyst, wherein the contents of titanium oxide, tin oxide and molybdenum oxide in the catalyst are respectively 20-90wt%, 2-55wt% and 0.3-40wt%. The method for catalytic degradation of the glycolate oligomer is simple to operate, can continuously degrade the glycolate oligomer, and can remarkably improve the conversion rate of the glycolate oligomer and the recovery rate of the methyl glycolate and the glycol.

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 method for catalytic degradation of glycolate oligomers, which is characterized by comprising the steps of contacting a raw material containing glycolate oligomers with low-carbon alcohol in the presence of a catalyst for reaction; Wherein the contents of titanium oxide, tin oxide and molybdenum oxide in the catalyst are respectively 20-90wt%, 2-55wt% and 0.3-40wt%.
  2. 2. The process according to claim 1, wherein the starting material for the glycolate containing oligomer is a glycolate containing oligomer-containing fusel oil, preferably comprising at least one of ethylene glycol, glycolic acid and methyl glycolate, and an oligomer produced by polymerization of at least one of ethylene glycol, glycolic acid and methyl glycolate; preferably, the weight average molecular weight of the oligomer is 200-5000g/mol.
  3. 3. A process according to claim 1 or 2, wherein the content of the oligomer in the starting material comprising glycolate oligomer is more than 5wt%, preferably 10-80wt%.
  4. 4. A process according to any one of claims 1 to 3, wherein the glycol content of the glycolate containing oligomer source material is 15 to 80wt%, the methyl glycolate content is 0 to 30wt% and the glycollic acid content is 0 to 10wt%.
  5. 5. The process of any one of claims 1-4, wherein the weight ratio of the glycolate oligomer-containing feedstock to the lower alcohol is 1 (0.3-20), the weight of the glycolate oligomer-containing feedstock being based on the weight of the glycolate oligomer.
  6. 6. The method according to any one of claims 1-5, wherein the lower alcohol is at least one of C1-C4 alcohols, preferably methanol.
  7. 7. The process of any one of claims 1-6, wherein the liquid hourly space velocity of the glycolate oligomer-containing feedstock is from 0.01 to 1h -1 , the weight of the glycolate oligomer-containing feedstock being based on the weight of the glycolate oligomer.
  8. 8. The process according to any one of claims 1 to 7, wherein the content of titanium oxide, tin oxide and molybdenum oxide in the catalyst is 25 to 85wt%, 3 to 50wt% and 0.5 to 35wt%, respectively, preferably 55 to 65wt%, 15 to 25wt% and 15 to 25wt%, respectively.
  9. 9. The method of any one of claims 1-8, wherein the preparing of the catalyst comprises milling, drying and shaping a mixture comprising titanium oxide, tin oxide and molybdenum oxide.
  10. 10. The process according to any one of claims 1 to 9, wherein the reaction conditions comprise a temperature of 80 to 250 ℃, a pressure of 0.1 to 4MPa, and a time of 20 to 120min; And/or the reaction is carried out in a continuous feed apparatus, wherein the apparatus comprises a continuous feed fixed bed or a continuous stirred tank reactor, preferably a continuous feed fixed bed.

Description

Method for catalytic degradation of glycolate oligomers Technical Field The invention relates to the field of chemical waste treatment, in particular to a method for catalyzing and degrading glycolate oligomers. Background Polyglycolide (PGA), also known as polyglycolic acid, is a highly crystalline, biodegradable aliphatic polymer, and is mainly used in the fields of medical consumables, mulch films, and the like. In areas where the coal content is sufficient, the PGA is mainly prepared from coal-derived synthesis gas, dimethyl oxalate (DMO) is first prepared from the coal-derived synthesis gas, and then methyl glycolate prepared by hydrogenation of the dimethyl oxalate is polymerized to form the PGA. In the synthetic method, a large amount of byproduct fusel oil containing the polymer is generated in the production process, and if the byproduct fusel oil is not recovered, the waste is caused greatly, so that the production cost is increased. At present, the recovery of polymers in fusel oil in the market is mainly divided into physical recovery and chemical recovery. Because the polymer has better degradability, the method of adopting chemical recovery is easier to operate than the method of adopting physical recovery. The chemical recovery is to depolymerize the polymer into monomers through alcoholysis, pyrolysis, hydrolysis, ammonolysis and other processes, and recycle the monomers. For the polymers produced in the PGA production process, there is currently no suitable method available on the market to decompose them into other recoverable monomers. Thus, there is an urgent need to develop a method of decomposing the polymer in the fusel oil, a by-product of the PGA process, into recoverable, valuable substances. Disclosure of Invention The invention aims to solve the problem that the glycollate oligomer in fusel oil cannot be effectively degraded and recycled in the prior art, and provides a method for catalyzing and degrading the glycollate oligomer. In order to achieve the above object, the present invention provides a method for degrading a glycolate oligomer, the method comprising contacting a raw material containing a glycolate oligomer with a lower alcohol in the presence of a catalyst to react, wherein the contents of titanium oxide, tin oxide and molybdenum oxide in the catalyst are 20 to 90wt%, 2 to 55wt% and 0.3 to 40wt%, respectively. Through the technical scheme, the beneficial effects of the invention at least comprise: The degradation method provided by the invention has simple process steps and mild conditions, can fully promote the degradation of the glycolate oligomer on the premise of not increasing the dosage of the low-carbon alcohol, can reduce the generation of byproducts while degrading the glycolate oligomer, and can convert the glycolate oligomer into substances with recovery value more, thereby reducing the cost. 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. The invention provides a method for degrading glycolate oligomers, which comprises the step of contacting and reacting a raw material containing glycolate oligomers with low-carbon alcohol in the presence of a catalyst. In the present invention, the contents of the titanium oxide, tin oxide and molybdenum oxide in the catalyst are preferably 20 to 90wt%, 2 to 55wt% and 0.3 to 40wt%, respectively. In the present invention, the starting material for the glycolate-containing oligomer may be derived from a glycolate-containing oligomer-containing fusel oil produced in the hydrogenation of commercial dimethyl oxalate, and preferably includes at least one of ethylene glycol, glycolic acid and methyl glycolate, and an oligomer produced by polymerization of at least one of ethylene glycol, glycolic acid and methyl glycolate. The oligomer means a homopolymer or a copolymer obtainable by polymerizing ethylene glycol, glycolic acid, methyl glycolate, etc. with each other. In the present invention, the weight average molecular weight of the oligomer may be 200 to 5000g/mol (as measured by high performance permeation gel chromatography (GPC)). In the present invention, the content of the glycolic acid ester-containing oligomer in the raw material may be 5wt% or more, preferably 10 to 80wt%. In the raw material containing the glycolate oligomer, the content of the glycol can be 15-80wt%, the content of the glycolate can be 0-30wt% and the content of the glycollic acid can be 0-10wt%. According to the present invention, the starting material for the glycolate-containing polymer, when i