Process for producing phenolic compounds from lignins

• US 5,807,952 A
• Filed: 05/02/1996
• Issued: 09/15/1998
• Est. Priority Date: 09/19/1994
• Status: Expired due to Fees

• Current Assignee: Midwest Research Institute
• Original Assignee: Midwest Research Institute
• Inventors: Agblevor, Foster A.
• Primary Examiner(s): Nutter, Nathan M.
• Application Number:
  US08/641,946
• Time in Patent Office: 866 Days
• Field of Search: 527/400, 530/500
• US Class Current: 527/400
• CPC Class Codes: C07B 41/02 of hydroxy or O-metal groups
• CPC Class Codes: C07C 41/01 Preparation of ethers
• CPC Class Codes: C07C 43/2055 containing more than one ether bond
• CPC Class Codes: C07C 43/23 containing hydroxy or O-metal groups

Abstract

A process for the production of low molecular weight phenolic compounds from lignins through the pyrolysis of the lignins in the presence of a strong base. In a preferred embodiment, potassium hydroxide is present in an amount of from about 0.1% to about 5% by weight, the pyrolysis temperature is from about 400° C. to about 600° C. at atmospheric pressure, and the time period for substantial completion of the reaction is from about 1-3 minutes. Examples of low molecular weight phenolic compounds produced include methoxyphenols, non-methoxylated phenols, and mixtures thereof.

Claims

1. A process for the production of a phenolic compound substantially in liquid form having a molecular weight from about 100 to (300) less than 168, which molecular weight was determined using multivariate techniques, from a single lignin or a mixture of different lignins, the process comprising:

a) pyrolyzing the lignin mixture of lignins in the presence of from about 0.1% to about 5% by weight of a strong base at a temperature of from about 400°

C. to about 600°

C. for a time period of from about one minute to about three minutes recover a yield of at least 15% low molecular weight phenolic compounds from the single lignin or the mixture of different lignins.

9. A process as claimed in claim 1 wherein the phenolic compound produced is chosen from the group consisting of methoxyphenols, non-methoxylated phenols, and mixtures thereof.

10. A process as claimed in claim 1 wherein from about 0.01% to about 0.9% by weight potassium ferricyanide is present.

11. A process as claimed in claim 1, wherein the lignin or mixture of lignins is sucrolin.

12. A process as claimed in claim 1, wherein the lignin or mixture of lignins are present in a simultaneous saccharification and fermentation residue.

13. A process as claimed in claim 1, wherein the yield is 50%-60% low molecular weight compounds from the lignin or lignins.

14. A process as claimed in claim 13, wherein the pyrolysis of the lignin or lignins produces 30%-50% (wt) char.

15. A process as claimed in claim 12, wherein the yield is 50%-16% low molecular weight compounds are from the lignin or lignins.

16. A process as claimed in claim 14, wherein the pyrolysis of the lignin or lignins produces 30%-50% (wt) char.

2. A process for the production of a phenolic compound substantially in liquid form having a molecular weight from about 100 to (300) less than 168, which molecular weight was determined using multivariate techniques, from a single lignin or a mixture of different lignins, the process comprising:

a. pyrolyzing the lignin or mixture of lignins in the presence of from about 0.1% to about 5% by weight of a strong base at a temperature of from about 400°

C. to about 600°

C. to recover a yield of at least 15% low molecular weight phenolic compounds from the single lignin or the mixture of different lignins, and wherein the time period is from about one to about five minutes.

3. A process as claimed in claim 2 wherein the process is performed at atmospheric pressure.

4. A process as claimed in claim 3 wherein the base is potassium hydroxide.

5. A process as claimed in claim 4 wherein lignins are chosen from the group consisting of mixed hardwood organosolv lignin, steam exploded yellow poplar lignin, steam exploded aspen lignin, kraft lignin, bagasse lignin, fungi treated corn stover, and mixtures thereof.

6. A process as claimed in claim 5 wherein the temperature is about 600°

C.

7. A process as claimed in claim 6 wherein the phenolic compound produced is chosen from the group consisting of methoxyphenols, non-methoxylated phenols, and mixtures thereof.

8. A process as claimed in claim 7 wherein from about 0.01% to about 0.9% by weight potassium ferricyanide is present.

17. A process for the production of a phenolic compound substantially in the form of a liquid having a molecular weight determined by multivariate techniques from about 100 to less than 168 from a single lignin or a mixture of different lignins, the process comprising:

a) pyrolyzing the lignin for a period of from about one to about five minutes at a temperature of from about 400°

C. to about 600°

C. in the presence of a strong base at a concentration sufficient to recover a yield of at least 15% of the phenolic compound.

18. A process as claimed in claim 17, wherein the process is performed at atmospheric pressure.

19. A process as claimed in claim 18, wherein the base is potassium hydroxide.

20. A process as claimed in claim 19, wherein lignins are chosen from the group consisting of mixed hardwood organosolv lignin, steam exploded yellow poplar lignin, steam exploded aspen lignin, kraft lignin, bagasse lignin, fungi treated corn stover, and mixtures thereof.

21. A process as claimed in claim 20, wherein the temperature is about 600°

C.

22. A process as claimed in claim 21, wherein the phenolic compound produced is chosen from the group consisting of methoxyphenols non-methoxylated phenols and mixtures thereof.

24. A process as claimed in claim 17, wherein the phenolic compound produced is chosen from the group consisting of methoxyphenols, non-methoxylated phenols, and mixtures thereof.

25. A process as claimed in claim 24, wherein from about 0.01 to about 0.9% by weight potassium ferricyanide is present.

26. A process as claimed in claim 25, wherein the lignin or mixture of lignins is sucrolin.

27. A process as claimed in claim 26, wherein the lignin or mixture of lignins are present in a simultaneous and fermentation residue.

28. A process as claimed in claim 27, wherein the yield is a 50%-60% low molecular weight compounds from lignin or lignins.

29. A process as claimed in claim 28, wherein the pyrolysis of the lignin or lignins produces 30%-50% (wt) char.

23. A process as claimed in claim 23, wherein from about 0.01% to about 0.9% by weight potassium ferricyanide is present.