Method and device for treating biomass and organic waste

• US 10,214,751 B2
• Filed: 10/29/2015
• Issued: 02/26/2019
• Est. Priority Date: 10/29/2014
• Status: Active Grant

• Current Assignee: Cambi Technology AS
• Original Assignee: Cambi Technology AS
• Inventors: Nilsen, Paal Jahre, Holte, Hans Rasmus
• Primary Examiner(s): Tichy, Jennifer M. H.
• Application Number:
  US15/523,136
• Publication Number:
  US 20170314046A1
• Time in Patent Office: 1,216 Days
• Field of Search: 424 931
• CPC Class Codes: C02F 11/04 Anaerobic treatment; Production of methane by such processes
• CPC Class Codes: C02F 11/18 by thermal conditioning by pyrolysis C02F11/10
• CPC Class Codes: C02F 11/185 by pasteurisation
• CPC Class Codes: C02F 2303/10 Energy recovery
• CPC Class Codes: C10G 3/00 Production of liquid hydrocarbon mixtures from oxygen-containing organic materials, e.g. fatty oils, fatty acids production from non-melting solid oxygen-containing carbonaceous materials C10G1/00
• CPC Class Codes: C12M 41/40 of pressure
• CPC Class Codes: C12M 45/20 Heating; Cooling heating or cooling apparatus for laboratory uses B01L7/00
• CPC Class Codes: C12M 47/02 Separating microorganisms from the culture medium; Concentration of biomass separating microorganisms from their culture media C12N1/02
• 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 7/10 substrate containing cellulosic material
• CPC Class Codes: Y02E 50/10 Biofuels, e.g. bio-diesel
• CPC Class Codes: Y02P 30/20 using bio-feedstock
• CPC Class Codes: Y02W 10/30 Wastewater or sewage treatment systems using renewable energies

Abstract

The present invention provides a method for treatment of biomass material by fermentation, said method comprises a pre-treatment of the biomass material by thermal hydrolysis and wet explosion, resulting in an intermediate product having a dry matter concentration above 25% and temperature above 90° C. which is to be introduced to the fermentation, wherein a part of the content of the digestion tank used for the fermentation is recirculated and mixed with a part of the intermediate product from the pre-treatment.

Claims

1. A method for treating a biomass material comprising at least the steps of:

pre-treatment of said biomass material comprising the steps of;

1) thermal hydrolysis at a temperature above 140°

C., followed by

2) wet explosion resulting in an intermediate product having a dry matter concentration above 25%, a pH below 6 and a temperature above 90°

C.;

subsequent fermentation of said intermediate product in a digestion tank,

wherein said intermediate product is introduced into said digestion tank by mixing said intermediate product into part of a content of said digestion tank being transported in a recirculation loop emerging from said digestion tank,

wherein said mixing is performed before the mixture of said intermediate product and said part of the content of said digestion tank enters said digestion tank,

wherein said part of the content of said digestion tank has a pH in a range of 7-8.5, and

wherein the pH after said mixing and before the mixture enters said digestion tank is above pH 6.

2. The method according to claim 1, wherein the intermediate product has a temperature above 100°

C.

3. The method according to claim 1, wherein the intermediate product has a pH below 5.

4. The method according to claim 1, wherein the method further comprises a wet oxidation, which is performed after the thermal hydrolysis and before the wet explosion.

5. The method according to claim 1, wherein the part of the content of the digestion tank is mixed with the intermediate product in a way that at least 10 parts by volume of the content of the digestion tank is mixed with one part by volume of the intermediate product.

6. The method according to claim 1, wherein a part of a gas phase from the pre-treatment is condensed by using a part of the content of the digestion tank as a cooling medium.

7. The method according to claim 6, wherein furfurals in the gas phase from the pre-treatment are separated by extraction after condensing.

8. The method according to claim 6, wherein volatile acids in the gas phase from the pre-treatment are recycled to the digestion tank after condensing.

9. The method according to claim 1, wherein the biomass material introduced to the method has a dry matter concentration above 50% by weight.

10. The method according to claim 1, wherein the biomass material introduced to the method is chosen from the group consisting of straw, wood, fibres, baits, paper pulp, slurry and household waste.

11. The method according to claim 1, wherein

the thermal hydrolysis is performed at a temperature above 140′

C and maintained for 5-30 minutes followed by,

wet explosion carried out by reducing a pressure from 5-35 bar to atmospheric pressure.

12. The method according to claim 1, wherein the pH after mixing the intermediate product with recirculated fermentation product from the digestion tank and before the mixture enters said digestion tank is above pH 6.5.

13. The method according to claim 1, wherein the content of the digestion tank and the intermediate product are mixed in a volume ratio range of 3:

1-30;

1.

14. The method according to claim 1, wherein the part of the content of the digestion tank is mixed with the intermediate product in a way that at least 20 parts by volume of the content of the digestion tank is mixed with one part by volume of the intermediate product.

15. The method according to claim 2, wherein the intermediate product has a pH below 5.

16. The method according to claim 2, wherein the method further comprises a wet oxidation, which is performed after the thermal hydrolysis and before the wet explosion.

17. The method according to claim 3, wherein the method further comprises a wet oxidation, which is performed after the thermal hydrolysis and before the wet explosion.

18. The method according to claim 2, wherein the part of the content of the digestion tank is mixed with the intermediate product in a way that at least 10 parts by volume of the content of the digestion tank is mixed with one part by volume of the intermediate product.