Continuous processes for hydrolyzing hemicelluloses from ligocellulosic materials with cleaning system

Patent metadata

Field	Value
Publication number	US-9435002-B2
Application number	US-201514714214-A
Country	US
Kind code	B2
Filing date	May 15, 2015
Priority date	Jun 7, 2014
Publication date	Sep 6, 2016
Grant date	Sep 6, 2016

Abstract

A continuous process for producing hemicellulose sugars from a biomass extraction liquor is provided. A system is configured for continuously producing hemicellulose sugars and/or hemicellulose derivatives from a biomass extraction liquor, the system comprising at least a first hydrolysis reactor and a second hydrolysis reactor. Each of the hydrolysis reactors is in switchable communication with (i) an operating feed stream of a biomass extraction liquor containing water, hemicellulose oligomers, and dissolved or suspended lignin, and (ii) a cleaning feed stream of a cleaning agent selected from the group consisting of steam, an alkaline solution, an organic solvent, and combinations thereof. The cleaning agent dissolves precipitated lignin formed from the lignin under the hydrolysis reaction conditions.

First claim

What is claimed is:

1. A continuous process for producing hemicellulose sugars from a biomass extraction liquor, said process comprising:
(a) providing or obtaining a biomass extraction liquor containing water, hemicellulose oligomers, and dissolved or suspended lignin;
(b) optionally introducing an acid catalyst to said biomass extraction liquor;
(c) for a first period of time, feeding said biomass extraction liquor through a first hydrolysis reactor under effective hydrolysis reaction conditions to hydrolyze said hemicellulose oligomers into hemicellulose monomers;
(d) at a first switching time, diverting said biomass extraction liquor from said first hydrolysis reactor to a second hydrolysis reactor;
(e) for a second period of time, feeding said biomass extraction liquor through said second hydrolysis reactor under said effective hydrolysis reaction conditions;
(f) during said second period of time, cleaning said first hydrolysis reactor by introducing a cleaning agent selected from the group consisting of steam, an alkaline solution, an organic solvent, and combinations thereof, wherein said cleaning agent is effective to dissolve precipitated lignin formed from said lignin under said effective hydrolysis reaction conditions;
(g) at a second switching time, diverting said biomass extraction liquor from said second hydrolysis reactor back to said first hydrolysis reactor or to a third hydrolysis reactor for hydrolyzing said hemicellulose oligomers into hemicellulose monomers, while concurrently cleaning said second hydrolysis reactor by introducing said cleaning agent to dissolve said precipitated lignin; and
(h) repeating steps (c) to (g) a plurality of times, thereby continuously producing hemicellulose sugars from said biomass extraction liquor.

2. The process of claim 1 , wherein said biomass extraction liquor is obtained from steam or liquid hot-water extraction of biomass.

3. The process of claim 1 , wherein said biomass extraction liquor is obtained from acidic liquid extraction of biomass.

4. The process of claim 1 , wherein said biomass extraction liquor is obtained from fractionation of biomass in the presence of water, a solvent for lignin, and an acid.

5. The process of claim 1 , wherein said process employs two hydrolysis reactors consisting of said first hydrolysis reactor and said second hydrolysis reactor.

6. The process of claim 1 , wherein said process employs three or more hydrolysis reactors comprising said first hydrolysis reactor, said second hydrolysis reactor, and said third hydrolysis reactor.

7. The process of claim 1 , wherein each of said hydrolysis reactors is, or is integrated with, a heat exchanger with indirect steam heating.

8. The process of claim 1 , wherein said biomass extraction liquor has a pH from about 0 to about 6.

9. The process of claim 8 , wherein said biomass extraction liquor has a pH from about 1 to about 4.

10. The process of claim 1 , wherein said biomass extraction liquor provided or obtained in step (a) contains suitable acidity for hydrolysis, and wherein step (b) is not performed.

11. The process of claim 10 , wherein said suitable acidity arises from the presence of lignosulfonic acid.

12. The process of claim 1 , wherein step (b) is performed, and wherein said acid catalyst is a sulfur-containing compound selected from the group consisting of sulfur dioxide, sulfurous acid, sulfur trioxide, sulfuric acid, sulfonic acid, lignosulfonic acid, and combinations thereof.

13. The process of claim 1 , wherein said effective hydrolysis reaction conditions include an acid content from about 0.1 wt % to about 20 wt %, a temperature from about 100° C. to about 220° C., and a residence time from about 2 minutes to about 4 hours.

14. The process of claim 13 , wherein said effective hydrolysis reaction conditions include an acid content from about 0.5 wt % to about 2 wt %, a temperature from about 120° C. to about 180° C., and a residence time from about 5 minutes to about 90 minutes.

15. The process of claim 1 , wherein each of said hydrolysis reactors is operated at the same reaction conditions.

16. The process of claim 1 , wherein said first period of time and said second period of time are each independently selected from about 1 day to about 3 months.

17. The process of claim 1 , wherein said cleaning agent includes said steam to mechanically dislodge said precipitated lignin.

18. The process of claim 1 , wherein said cleaning agent includes said alkaline solution to chemically dissolve or react with said precipitated lignin, wherein said alkaline solution comprises a base selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium oxide, magnesium hydroxide, ammonia, and combinations thereof.

19. The process of claim 1 , wherein said cleaning agent includes said organic solvent to chemically dissolve said precipitated lignin, wherein said organic solvent comprises a compound selected from the group consisting of an aliphatic alcohol, an aromatic alcohol, a ketone, an aldehyde, and combinations thereof.

20. The process of claim 1 , wherein said cleaning agent includes said steam to mechanically dislodge said precipitated lignin, followed by said alkaline solution to chemically dissolve or react with said precipitated lignin or with mechanically dislodged lignin.

21. The process of claim 1 , wherein said cleaning agent includes said steam to mechanically dislodge said precipitated lignin, followed by said organic solvent to chemically dissolve said precipitated lignin or mechanically dislodged lignin.

22. The process of claim 1 , wherein said cleaning agent includes steam, said alkaline solution, and said organic solvent, introduced in any sequence.

Assignees

• Api Ip Holdings Llc

Inventors

• Dang Zheng
• Tunc Mehmet Sefik
• Wang Ziyu

Classifications

• C13K13/002 Primary

  Xylose · CPC title

• C07C51/00

  Preparation of carboxylic acids or their salts, halides or anhydrides (of acids by hydrolysis of oils, fats or waxes C11C) · CPC title

• C13K13/00

  Sugars not otherwise provided for in this class · CPC title

• C07D307/50

  Preparation from natural products · CPC title

• C13K1/02

  obtained by saccharification of cellulosic materials (manufacture of fodder A23K10/32) · CPC title