Process for Generating Methane and/or Methane Hydrate From Biomass

• US 20090126274A1
• Filed: 06/19/2006
• Published: 05/21/2009
• Est. Priority Date: 10/04/2005
• Status: Active Grant

• Current Assignee: Paul Scherrer-Institut (Schweizerische Eidgenossenschaft)
• Original Assignee: Paul Scherrer-Institut (Schweizerische Eidgenossenschaft)
• Inventors: Vogel, Frederic, Stucki, Samuel, Truong, Thanh-Binh, Waldner, Maurice
• Granted Patent: US 8,475,549 B2
• Time in Patent Office: Days
• US Class Current: 48/127.700
• CPC Class Codes: B09B 3/00 Destroying solid waste or transforming solid waste into something useful or harmless
• CPC Class Codes: C02F 11/04 Anaerobic treatment; Production of methane by such processes
• CPC Class Codes: C02F 11/08 Wet air oxidation
• CPC Class Codes: C05F 3/00 Fertilisers from human or animal excrements, e.g. manure
• CPC Class Codes: C05G 1/00 Mixtures of fertilisers belonging individually to different subclasses of C05
• CPC Class Codes: C10J 2200/06 Catalysts as integral part of gasifiers
• CPC Class Codes: C10J 2300/0916 Biomass
• CPC Class Codes: C10J 2300/0959 Oxygen
• CPC Class Codes: C10J 2300/0979 as supercritical steam
• CPC Class Codes: C10J 3/00 Production of combustible gases containing carbon monoxide from solid carbonaceous fuels destructive distillation processes C10B
• CPC Class Codes: C10J 3/78 High-pressure apparatus
• CPC Class Codes: C10L 3/08 Production of synthetic natural gas
• CPC Class Codes: C10L 5/44 on vegetable substances
• CPC Class Codes: Y02A 40/20 Fertilizers of biological origin, e.g. guano or fertilizers made from animal corpses
• 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: Y02P 20/52 using catalysts, e.g. selective catalysts
• CPC Class Codes: Y02P 20/54 using solvents, e.g. supercritical solvents or ionic liquids
• CPC Class Codes: Y02W 30/40 Bio-organic fraction processing; Production of fertilisers from the organic fraction of waste or refuse

Abstract

To generate methane from biomass, a biomass pulp is produced from the biomass with a desired dry mass content being set, and the biomass pulp is placed under pressure. The biomass pulp is heated under pressure in order to liquefy the solid organic components of the biomass pulp. The pressurized and heated biomass pulp is heated further to at least the critical temperature of the biomass pulp. Solids precipitated under pressure and increased temperature are separated from the fluid phase. At least a part of the remaining fluid phase is gasified under pressure and increased temperature by means of a reactor to form a methane-rich gas.

Claims

1. A method for generating methane from biomass, comprising:

producing a biomass pulp from the biomass with a desired dry mass content being set,

placing the biomass pulp under pressure,

heating the biomass pulp under pressure in order to liquefy the solid organic components of the biomass pulp,

further heating the pressurized and heated biomass pulp to at least a critical temperature appropriate to the biomass pulp,

separating solids precipitated under pressure and increased temperature from the fluid phase, and

gasifying at least a part of the remaining fluid phase under pressure and increased temperature by means of a reactor to form a methane-rich gas.

2. The method claim 1, wherein the pressurized methane-rich gas is separated from the remaining fluid phase.

3. The method of claim 1, wherein the methane-rich gas is cooled down under pressure and solid methane hydrate forming during this process is separated from the remaining gas components, in particular CO₂ and/or carbon monoxide and hydrogen, as well as preferably from the residual water.

4. The method of claim 3, wherein the methane generated during the gasification from the pressurized methane-rich gas, preferably using the pressure, by means of a washing column, membrane separation or adsorber method, is separated from remaining gas components, in particular CO₂ and/or carbon monoxide and/or hydrogen.

5. The method of claim 1, wherein producing the biomass includes comminuting the biomass by wet grinding and setting by supplying water or separating water a dry mass content between 5 to 80 mass percent.

6. The method of claim 5, wherein additives are added to improve pumpability of the biomass pulp.

7. The method of claim 1, wherein placing the biomass pulp under pressure includes bringing the biomass to a pressure in the range from 200 to 400 bar.

8. The method of claim 7, wherein the biomass pulp is heated under pressure to 200 to 400°

C.

9. The method of claim 8 wherein at least one of static mixed elements and a catalyst is used to assist better heating and liquefaction.

10. The method of claim 1, wherein a higher temperature level obtained by further heating the biomass pulp lies at least at the critical temperature.

11. The method of claim 10, wherein the higher temperature level is reached by means of one of:

an external heat input,

and adding of suitable oxidizing agents such that a partial oxidation of organic components of the biomass pulp takes place.

12. The method of claim 10, wherein salts and residual solids are precipitated and collected, the collected precipitations being removed from the process continuously or periodically prior to the gasification.

13. The method of claim 1, wherein a catalyst is used to expedite setting of a desired product gas composition.

14. The method of claim 13, wherein the catalyst contains one of nickel, ruthenium and rhodium as an active metal.

15. The method of claim 12, wherein a catalytic reactor is embodied as one of a fluidized-bed reactor, as a monolithic reactor, a wall reactor and a tube reactor, with associated tubes being coated with the catalyst or catalytically coated metal plates layered in a tube being used.

16. The method of claim 1, wherein catalytic gasification is executed under supercritical conditions.