Method for producing polyoxymethylene dimethyl ethers from feedstock of concentrated formaldehyde

Patent metadata

Field	Value
Publication number	US-2016168307-A1
Application number	US-201514965571-A
Country	US
Kind code	A1
Filing date	Dec 10, 2015
Priority date	Dec 12, 2014
Publication date	Jun 16, 2016
Grant date	—

Abstract

The present invention pertains to the technical field of energy resource chemical industry, and in particular relates to a process for producing polyoxymethylene dimethyl ethers by directly using concentrated formaldehyde aqueous solution as feedstock to catalytically react with methanol and/or methylal in a fixed bed reactor. The method of the present invention uses concentrated formaldehyde aqueous solution with a concentration of over 80% by weight to react with methanol and/or methylal, in the presence of an acidic catalyst, to produce the required polyoxymethylene dimethyl ethers. As compared with using paraformaldehyde powder as feedstock, the method of the present invention accelerates the depolymerization process of paraformaldehyde, thus significantly reduces the time required for product synthesis and makes the synthesis reaction able to be carried out in a fixed bed reactor; meanwhile, as compared with using formaldehyde aqueous solution with a low concentration as feedstock, the method of the present invention also significantly increases the yield rate of the target product.

First claim

1 . A method for producing polyoxymethylene dimethyl ethers from feedstock of concentrated formaldehyde aqueous solution, comprising:
using concentrated formaldehyde aqueous solution with a concentration of over 80% by weight as feedstock to react with methanol and/or methylal, in the presence of an acidic catalyst, to produce the required polyoxymethylene dimethyl ethers.

2 . The method in accordance with claim 1 , wherein, the concentration of formaldehyde in the concentrated formaldehyde aqueous solution is 85% by weight.

3 . The method in accordance with claim 2 , wherein, the concentrated formaldehyde aqueous solution is an intermediate product obtained before a spray drying granulation step during manufacturing of paraformaldehyde.

4 . The method in accordance with claim 1 , wherein, the reaction for producing polyoxymethylene dimethyl ethers is carried out in a fixed bed reactor.

5 . The method in accordance with claim 4 , wherein, the fixed bed reactor is an adiabatic reactor or a multitubular reactor.

6 . The method in accordance with claim 1 , wherein, the acidic catalyst is selected from the group consisting of strong acidic cation exchange resin, solid acid catalyst, and molecular sieve based catalyst.

7 . The method in accordance with claim 1 , wherein, the reaction is carried out at a temperature of 70-200° C., a pressure of 0.1-2.0 MPa, and a space velocity of 0.5-4.0 h −1 .

8 . The method in accordance with claim 1 , wherein, the molar ratio of the methanol and/or methylal to the formaldehyde in the concentrated formaldehyde aqueous solution is 1:1 to 1:4.

9 . The method in accordance with claim 1 , wherein, the reaction is carried out under protection of an inert gas.

10 . The method in accordance with claim 1 , wherein, the reaction further comprises refining the polyoxymethylene dimethyl ether products.

11 . The method in accordance with claim 2 , wherein, the reaction for producing polyoxymethylene dimethyl ethers is carried out in a fixed bed reactor.

12 . The method in accordance with claim 3 , wherein, the reaction for producing polyoxymethylene dimethyl ethers is carried out in a fixed bed reactor.

13 . The method in accordance with claim 2 , wherein, the acidic catalyst is selected from the group consisting of strong acidic cation exchange resin, solid acid catalyst, and molecular sieve based catalyst.

14 . The method in accordance with claim 3 , wherein, the acidic catalyst is selected from the group consisting of strong acidic cation exchange resin, solid acid catalyst, and molecular sieve based catalyst.

15 . The method in accordance with claim 4 , wherein, the acidic catalyst is selected from the group consisting of strong acidic cation exchange resin, solid acid catalyst, and molecular sieve based catalyst.

16 . The method in accordance with claim 5 , wherein, the acidic catalyst is selected from the group consisting of strong acidic cation exchange resin, solid acid catalyst, and molecular sieve based catalyst.

17 . The method in accordance with claim 2 , wherein, the reaction is carried out at a temperature of 70-200° C., a pressure of 0.1-2.0 MPa, and a space velocity of 0.5-4.0 h −1 .

18 . The method in accordance with claim 3 , wherein, the reaction is carried out at a temperature of 70-200° C., a pressure of 0.1-2.0 MPa, and a space velocity of 0.5-4.0 h −1 .

19 . The method in accordance with claim 4 , wherein, the reaction is carried out at a temperature of 70-200° C., a pressure of 0.1-2.0 MPa, and a space velocity of 0.5-4.0 h −1 .

20 . The method in accordance with claim 5 , wherein, the reaction is carried out at a temperature of 70-200° C., a pressure of 0.1-2.0 MPa, and a space velocity of 0.5-4.0 h −1 .

Assignees

• Dongfang Hongsheng New Energy Applic Technology Res Inst Co Ltd
• Jiangsu Kaimao Chemical Technology Co Ltd
• Univ China Petroleum

Inventors

• Shang Hongyan
• Hong Zhengpeng
• Ye Zimao
• Xiang Jiayong
• Xue Zhenzhen

Classifications

• C08G16/0225 Primary

  containing oxygen · CPC title

• C08G2/04 Primary

  Polymerisation by using compounds which act upon the molecular weight, e.g. chain-transferring agents · CPC title

• C08G2/34

  by etherification · CPC title

• C07C41/56 Primary

  by condensation of aldehydes, paraformaldehyde, or ketones · CPC title

• C08G2/06

  Catalysts (Catalysts in general B01J) · CPC title