Lignocellulosic conversion process comprising sulfur dioxide and/or sulfurous acid pretreatment

• US 10,513,714 B2
• Filed: 03/16/2016
• Issued: 12/24/2019
• Est. Priority Date: 03/16/2015
• Status: Active Grant

• Current Assignee: Iogen Corporation
• Original Assignee: Iogen Corporation
• Inventors: Foody, Brian, Tolan, Jeffrey S.
• Primary Examiner(s): Fan, Lynn Y
• Application Number:
  US15/550,515
• Publication Number:
  US 20190106718A1
• Time in Patent Office: 1,378 Days
• CPC Class Codes: C01C 1/164 Ammonium chloride
• CPC Class Codes: C01C 1/24 Sulfates of ammonium C01C1/14 takes precedence
• CPC Class Codes: C01D 5/00 Sulfates or sulfites of sodium, potassium or alkali metals in general sulfites in general C01B17/62
• CPC Class Codes: C01D 5/04 Preparation of sulfates with the aid of sulfurous acid or sulfites, e.g. Hargreaves process pyrosulfites or metabisulfites C01D5/145
• CPC Class Codes: C05C 3/00 Fertilisers containing other salts of ammonia or ammonia itself, e.g. gas liquor
• CPC Class Codes: C05D 1/02 Manufacture from potassium chloride or sulfate or double or mixed salts thereof
• CPC Class Codes: C05F 17/10 Addition or removal of substances other than water or air to or from the material during the treatment for activating or stimulating the treatment C05F17/20
• CPC Class Codes: C07G 1/00 Lignin; Lignin derivatives
• CPC Class Codes: C08H 8/00 Macromolecular compounds derived from lignocellulosic materials pretreatment thereof B27N
• CPC Class Codes: C10L 1/02 essentially based on components consisting of carbon, hydrogen, and oxygen only
• CPC Class Codes: C12F 3/00 Recovery of by-products
• CPC Class Codes: C12P 19/02 Monosaccharides 2-ketogulonic acid C12P7/60
• CPC Class Codes: C12P 19/14 produced by the action of a carbohydrase (EC 3.2.x), e.g. by alpha-amylase , e.g. by cellulase, hemicellulase
• CPC Class Codes: C12P 2201/00 Pretreatment of cellulosic or lignocellulosic material for subsequent enzymatic treatment or hydrolysis
• CPC Class Codes: C12P 2203/00 Fermentation products obtained from optionally pretreated or hydrolyzed cellulosic or lignocellulosic material as the carbon source ethanol C12P7/10
• CPC Class Codes: C12P 5/023 Methane
• CPC Class Codes: C12P 7/10 substrate containing cellulosic material
• CPC Class Codes: C12P 7/16 Butanols
• CPC Class Codes: C12P 7/22 aromatic
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel
• CPC Class Codes: Y02E 50/30 : Fuel from waste, e.g. synthetic alcohol or diesel
• CPC Class Codes: Y02P 20/145 : the feedstock being materials of biological origin
• CPC Class Codes: Y02W 30/40 : Bio-organic fraction processing; Production of fertilisers from the organic fraction of waste or refuse

Abstract

Provided herein is a process for producing one or more products from a lignocellulosic feedstock. The process comprises treating the lignocellulosic feedstock by contacting the feedstock at least sulfur dioxide, sulfurous acid, or a combination thereof to produce a pretreated feedstock comprising one or more sulfonic acids. A process stream comprising one or more sulfonic acids is subsequently treated in a wet oxidation step to produce a stream comprising at least soluble oxidized phenolic compounds. The soluble oxidized phenolic compounds are then fed to an anaerobic digestion to produce methane. Optionally, hydrogen sulfide is produced during the anaerobic digestion. The hydrogen sulfide may then be converted to an acid selected from sulfur dioxide, sulfurous acid or a combination thereof in one or more steps. The acid may then be re-used in treatment as desired.

Claims

1. A process for producing one or more products from a lignocellulosic feedstock comprising:

(i) treating the lignocellulosic feedstock by contacting same with at least sulfur dioxide, sulfurous acid, or a combination thereof to produce a pretreated feedstock composition comprising one or more sulfonic acids;

(ii) hydrolyzing the pretreated feedstock with cellulase enzymes to produce glucose;

(iii) fermenting the glucose to produce a fermentation product;

(iv) providing a process stream comprising the one or more sulfonic acids produced in step (i);

(v) treating the process stream comprising the one or more sulfonic acids by a wet oxidation step to produce a stream comprising a sulfate salt and soluble oxidized phenolic compounds; and

(vi) feeding at least the soluble oxidized phenolic compounds to anaerobic digestion to produce methane.

4. The process of claim 1, wherein the treatment of step (i) comprises combining gaseous sulfur dioxide with a slurry comprising the lignocellulosic feedstock.

5. The process of claim 1, wherein the treatment of step (i) comprises combining a solution of sulfurous acid with the lignocellulosic feedstock.

6. The process of claim 1, wherein the anaerobic digestion produces hydrogen sulfide.

7. The process of claim 6, wherein the process further comprises

(a) treating the hydrogen sulfide to produce elemental sulfur or an oxide of sulfur;

(b) recovering an acid comprising sulfurous acid, sulfur dioxide or a combination thereof from the elemental sulfur or oxide of sulfur; and

(c) using the acid recovered in step (b) in step (i) of treating the lignocellulosic feedstock.

8. The process of claim 1, further comprising recovering the fermentation product to produce a recovered product and a remaining stream comprising one or more sulfonic acids.

9. The process of claim 8, wherein the remaining stream is treated by the wet oxidation.

10. The process of claim 1, wherein the wet oxidation step comprises the addition of air or oxygen.

11. The process of claim 1, wherein the one or more sulfonic acids comprise a lignosulfonate, a lignosulfonic acid, or a combination thereof.

12. The process of claim 1, wherein the sulfate salt is recovered from the process stream prior to anaerobic digestion.

2. A process for producing one or more products from a lignocellulosic feedstock comprising:

(i) treating the lignocellulosic feedstock by contacting same with at least sulfur dioxide, sulfurous acid, or a combination thereof to produce a pretreated feedstock composition comprising one or more sulfonic acids;

(ii) hydrolyzing the pretreated feedstock with cellulase enzymes to produce glucose;

(iii) fermenting the glucose to produce an alcohol;

(iv) recovering the alcohol produced in step (iii) to produce recovered alcohol and a remaining stream comprising the one or more sulfonic acids;

(v) treating the remaining stream comprising the one or more sulfonic acids by a wet oxidation step to produce a stream comprising a sulfate salt and soluble oxidized phenolic compounds; and

(vi) feeding at least the soluble oxidized phenolic compounds to anaerobic digestion to produce methane.

3. A process for producing one or more products from a lignocellulosic feedstock comprising:

(i) treating the lignocellulosic feedstock by contacting same with at least sulfur dioxide, sulfurous acid, or a combination thereof to produce a pretreated feedstock composition comprising one or more sulfonic acids;

(ii) providing a process stream comprising the one or more sulfonic acids produced in step (i);

(iii) treating the process stream comprising the one or more sulfonic acids by a wet oxidation step to produce a stream comprising a sulfate salt and soluble oxidized phenolic compounds; and

(iv) feeding at least the soluble oxidized phenolic compounds to anaerobic digestion to produce methane.

13. A process for producing one or more products from a lignocellulosic feedstock comprising:

(i) treating the lignocellulosic feedstock by contacting same with at least sulfur dioxide, sulfurous acid, or a combination thereof to produce a pretreated feedstock composition comprising one or more sulfonic acids;

(ii) providing a process stream comprising the one or more sulfonic acids produced in step (i);

(iii) treating the process stream comprising the one or more sulfonic acids by a wet oxidation step to produce a stream comprising soluble oxidized phenolic compounds; and

(iv) feeding at least the soluble oxidized phenolic compounds to anaerobic digestion to produce methane.