Method for hydrolysis of biomass in pulping spent liquor
View Patent ↗A method for the hydrolysis of cellulosic materials using spent liquor. The spent liquor is derived from a pulping operation or is hydrolyzate from another cellulosic biomass process. The process can be implemented in a batch or semi continuous or continuous process. The hydrolyzate is fermented to a useful product and purified. Combustible biomass residues and chemicals are used to provide energy and chemical recovery.
1. A process of hydrolyzing a cellulosic biomass feedstock into monomer sugars, said process comprising:
(a) providing a cellulosic biomass feedstock;
(b) providing spent liquor media containing dissolved solids and one or more sulfur-containing species selected from sulfur dioxide, sulfurous acid, or sulfuric acid, wherein said spent liquor media is derived from separate pulping or hydrolysis of a second cellulosic biomass material;
(c) impregnating said cellulosic biomass feedstock with said spent liquor media, to generate a mixture;
(d) adjusting the acidity of said mixture with an acid to reduce pH of said mixture; and
(e) cooking said mixture to generate a hydrolyzate comprising monomer sugars derived from said cellulosic biomass feedstock.
2. The process of claim 1 , wherein said cellulosic biomass feedstock contains hemicelluloses.
3. The process of claim 1 , wherein said spent liquor media is spent pulping liquor from a pulping process.
4. The process of claim 1 , wherein said spent liquor media is derived from hydrolysis of a second cellulosic biomass material having a higher recalcitrance compared to said cellulosic biomass feedstock.
5. The process of claim 1 , wherein said spent liquor media is derived from separate pulping of said second cellulosic biomass material.
6. The process of claim 1 , wherein said spent liquor media is derived from separate hydrolysis of said second cellulosic biomass material.
7. The process of claim 1 , said process further comprising heating said mixture and releasing free sulfur dioxide and volatiles.
8. The process of claim 1 , wherein said spent liquor media contains a sulfite selected from the group consisting of ammonium sulfite, calcium sulfite, sodium sulfite, magnesium sulfite, and any combinations thereof.
9. The process of claim 1 , wherein said spent liquor media contains lignosulfonic acid.
10. The process of claim 1 , wherein said spent liquor media contains an alcohol.
11. The process of claim 1 , wherein said spent liquor media contains water, sodium sulfide, and sodium hydroxide.
12. The process of claim 1 , wherein said acid in step (d) is selected from the group consisting of sulfuric acid, sulfur dioxide, an organic acid, and any combination thereof.
13. The process of claim 1 , said process further comprising introducing a base to said hydrolyzate to increase pH of said hydrolyzate, and then fermenting said monomer sugars contained in said hydrolyzate to produce a fermentation product.
14. The process of claim 13 , wherein said fermentation product is ethanol.
15. The process of claim 13 , said process further comprising recovering said fermentation product.
16. The process of claim 1 , wherein said cellulosic biomass feedstock contains lignin, and wherein said cooking in step (e) comprises sulfonating at least a portion of said lignin contained in said mixture.
17. The process of claim 1 , said process further comprising removing lignin from said hydrolyzate.
18. A process of hydrolyzing a cellulosic biomass feedstock into monomer sugars, said process comprising:
(a) providing a cellulosic biomass feedstock;
(b) providing spent liquor containing dissolved solids and one or more sulfur-containing species selected from sulfur dioxide, sulfurous acid, or sulfuric acid, wherein said spent liquor media is derived from separate pulping or hydrolysis of a second cellulosic biomass material;
(c) impregnating said cellulosic biomass feedstock with said spent liquor, to generate a first mixture;
(d) heating said first mixture and releasing free sulfur dioxide and volatiles, to generate a second mixture;
(e) adjusting the acidity of said second mixture with an acid to reduce pH of said second mixture;
(f) cooking said second mixture to generate a hydrolyzate comprising monomer sugars derived from said cellulosic biomass feedstock; and
(g) recycling and reusing at least some of said free sulfur dioxide from step (d).
19. The process of claim 18 , wherein said spent liquor is spent pulping liquor from a pulping process.
20. A process of hydrolyzing a cellulosic biomass feedstock into monomer sugars, said process comprising:
(a) providing a first cellulosic biomass feedstock;
(b) providing spent liquor media derived from separate acid hydrolysis of a second cellulosic biomass feedstock having a higher recalcitrance compared to said first cellulosic biomass feedstock, wherein said spent liquor media contains dissolved solids and one or more sulfur-containing species selected from sulfur dioxide, sulfurous acid, or sulfuric acid;
(c) impregnating said first cellulosic biomass feedstock with said spent liquor media, to generate a mixture;
(d) adjusting the acidity of said mixture with an acid to reduce pH of said mixture; and
(e) cooking said mixture to generate a hydrolyzate comprising monomer sugars derived from said cellulosic biomass feedstock.
21. The process of claim 20 , said process further comprising heating said mixture and releasing free sulfur dioxide and volatiles.