Method for producing tetrahydrofuran

Patent metadata

Field	Value
Publication number	US-9598388-B2
Application number	US-201414147932-A
Country	US
Kind code	B2
Filing date	Jan 6, 2014
Priority date	Jul 4, 2011
Publication date	Mar 21, 2017
Grant date	Mar 21, 2017

Abstract

The present invention is concerned with a method for producing tetrahydrofuran including carrying out a dehydration cyclization reaction of 1,4-butanediol in the presence of an acid catalyst having a pKa value of not more than 4 within a reactor, wherein a raw material liquid containing 1,4-butanediol to be provided for the reaction contains from 0.01 to 0.35% by weight of 2-(4-hydroxybutoxy)-tetrahydrofuran and 1 ppm by weight or more and not more than 1,000 ppm by weight of at least one of an amine and an amide in terms of a concentration as converted into a nitrogen atom.

First claim

The invention claimed is:

1. A method for producing tetrahydrofuran, comprising:
feeding a raw material liquid in a reactor, wherein the raw material liquid comprises 1,4-butanediol, from 0.01 to 0.35% by weight of 2-(4-hydroxybutoxy) -tetrahydrofuran, and 1 ppm by weight or more and not more than 1,000 ppm by weight of at least one of an amine and an amide in terms of a concentration as converted into a nitrogen atom; and
carrying out a dehydration cyclization reaction of 1,4-butanediol in the reactor in the presence of an acid catalyst having a pKa value of not more than 4.

2. A method for producing tetrahydrofuran, comprising:
carrying out a dehydration cyclization reaction of 1,4-butanediol in a reactor in the presence of an acid catalyst having a pKa value of not more than 4,
wherein a reaction liquid within the reactor comprises 1 ppm by weight or more and not more than 10,000 ppm by weight of at least one of an amine and an amide in terms of a concentration as converted into a nitrogen atom.

3. The method according to claim 1 ,
wherein a reaction liquid within the reactor comprises 1 ppm by weight or more and not more than 10,000 ppm by weight of the at least one of an amine and an amide in terms of a concentration as converted into a nitrogen atom.

4. The method according to claim 1 ,
wherein a reaction liquid within the reactor comprises 0.1% by weight or more and not more than 10% by weight of water.

5. The method according to claim 1 , further comprising:
extracting a gas comprising tetrahydrofuran and water present in a gas phase within the reactor to outside of the reactor.

6. The method according to claim 1 ,
wherein a temperature of a reaction liquid within the reactor is 80° C. or higher and not higher than 250° C.

7. The method according to claim 1 , further comprising:
heating crude 1,4-butanediol at 80° C. or higher in the presence of the at least one of an amine and an amide to reduce a content of 2-(4-hydroxybutoxy)-tetrahydrofuran in the crude 1,4-butanediol, prior to the feeding.

8. The method according to claim 2 ,
wherein the reaction liquid within the reactor comprises 0.1% by weight or more and not more than 10% by weight of water.

9. The method according to claim 2 , further comprising:
extracting a gas comprising tetrahydrofuran and water present in a gas phase within the reactor to outside of the reactor.

10. The method according to claim 2 ,
wherein a temperature of the reaction liquid within the reactor is 80° C. or higher and not higher than 250° C.

11. The method according to claim 2 , further comprising:
heating crude 1,4-butanediol at 80° C. or higher in the presence of the at least one of an amine and an amide to reduce a content of 2-(4-hydroxybutoxy)-tetrahydrofuran in the crude 1,4-butanediol, prior to the carrying out of the dehydration cyclization reaction of 1,4-butanediol.

12. The method according to claim 1 , wherein the acid catalyst is organic sulfonic acid.

13. The method according to claim 2 , wherein the acid catalyst is organic sulfonic acid.

14. The method according to claim 1 ,
wherein the amine is at least one selected from the group consisting of octlyamine, nonylamine, 1-aminodecane, aniline, phenethylamine, dipentylamine, dihexylamine, diheptylamine, dicyclohexylamine, N-methylaniline, tributylamine, tripentylamine, N,N-dimethylaniline, 1,3-propanediamine, N,N-dimethyl-1,6-hexanediamine, N-butylpyrrole, N-butyl-2,3-dihydropyrrole, N-butylpyrrolidine, 2,3-dihydro-1H-indole, 4-aminomethylpiperidine, 4-dimethylaminopyridine, 1,2,3,4-tetrahydroquinoline, 4-amino-5,6-dihydro-2-methylpyrimidine, 2,3,5,6-tetramethylpyrazine, 3,6-dimethylpyridazine, 4-aminobutanol, 2-aminobutanol, 2-ethylmorpholine, N-methoxycarbonylmorpholine, prolinol, 3-hydroxypiperidine, 4-hydroxypiperidine, tetrahydrofurfurylamine, and 3-aminotetrahydropyran, and
the amide is at least one selected from the group consisting of acetamide, N-methylacetamide, N-ethylacetamide, N,N-dimethylacetamide, benzamide, 2-pyrrolidone, N-methylpyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, 2-piperidone, and N-methylpiperidone.

15. The method according to claim 2 ,
wherein the amine is at least one selected from the group consisting of octylamine, nonylamine, 1-aminodecane, aniline, phenethylamine, dipentylamine, dihexylamine, diheptylamine, dicyclohexylamine, N-methylaniline, tributylamine, tripentylamine, N,N-dimethylaniline, 1,3-propanediamine, N,N-dimethyl-1,6-hexanediamine, N-butylpyrrole, N-butyl-2,3-dihydropyrrole, N-butylpyrrolidine, 2,3-dihydro-1H-indole, 4- aminomethylpiperidine, 4-dimethylaminopyridine, 1,2,3,4-tetrahydroquinoline, 4-amino-5,6- dihydro-2-methylpyrimidine, 2,3,5,6-tetramethylpyrazine, 3,6-dimethylpyridazine, 4- aminobutanol, 2-aminobutanol, 2-ethylmorpholine, N-methoxycarbonylmorpholine, prolinol, 3-hydroxypiperidine, 4-hydroxypiperidine, tetrahydrofurfurylamine, and 3-aminotetrahydropyran, and
the amide is at least one selected from the group consisting of acetamide, N-methylacetamide, N-ethylacetamide, N,N-dimethylacetamide, benzamide, 2-pyrrolidone, N-methylpyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, 2-piperidone, and N-methylpiperidone.

16. The method according to claim 7 , wherein the heating of the crude 1,4-butanediol is carried out such that the raw material liquid comprises from 0.01 to 0.35% by weight of 2-(4-hydroxybutoxy)-tetrahydrofuran.

17. The method according to claim 7 , wherein the crude 1,4-butanediol has a pH value of from 7 to 12.

18. The method according to claim 1 , wherein the acid catalyst is a metal-free organic acid or a metal-free phosphoric acid.

19. The method according to claim 2 , wherein the acid catalyst is a metal-free organic acid or a metal-free phosphoric acid.

Assignees

• Mitsubishi Chem Corp

Inventors

• Izawa Yusuke
• Utsunomiya Masaru
• Konishi Norikazu
• Tanaka Kouta

Classifications

• C07D307/08 Primary

  Preparation of tetrahydrofuran · CPC title

• C07B61/00 Primary

  Other general methods · CPC title

• B01D3/002

  by continuous methods · CPC title

• B01D3/009

  in combination with chemical reactions · CPC title

• Y02P20/10

  Process efficiency · CPC title