Method for Increased Production of Biogas

• US 20080124775A1
• Filed: 11/28/2005
• Published: 05/29/2008
• Est. Priority Date: 11/26/2004
• Status: Active Grant

• Current Assignee: Schmack Biogas GmbH
• Original Assignee: University of Szeged
• Inventors: Bagi, Zoltan, Kovacs, Kornel, Rakhely, Gabor, Rakhelyne Perei, Katalin
• Granted Patent: US 7,888,085 B2
• Time in Patent Office: Days
• US Class Current: 435/167
• CPC Class Codes: C02F 2003/001 using granular carriers or supports for the microorganisms
• CPC Class Codes: C02F 2103/20 from animal husbandry
• CPC Class Codes: C02F 2301/106 Thermophilic treatment
• CPC Class Codes: C02F 3/286 including two or more steps
• CPC Class Codes: C02F 3/34 characterised by the microorganisms used
• CPC Class Codes: Y02E 50/30 Fuel from waste, e.g. synthetic alcohol or diesel

Abstract

The invention relates to a method for increasing biogas production of thermophilic anaerobe systems. More closely, a biomass containing a consortium comprising polymer-degrading, acetogenic and methanogenic microorganisms is inoculated with a microorganism culture before the start of or during biogas production. Said microorganism is a thermophilic, acetogenic, hydrogen producing bacterium. As an example, Caldicellulosiruptor saccharolyticus is applied. According to the invention production if methane containing biogas is significantly increased.

The invention is useful for intensifying biogas production and thereby increasing its feasibility.

Claims

1. A method for increasing methane production in a biomass fermenting system, in which biomass is fermented under anaerobic and thermophilic conditions by a consortium comprising polymer degrading microorganisms, acetogenic microorganisms and methanogenic microorganisms, wherein methane production in increased by using a thermophilic, anaerobic, acetogenic, hydrogen-producing bacterium.

2. The method of claim 1, wherein, before the start of biogas production or during biogas production, a culture of thermophilic, anaerobic, acetogenic, hydrogen-producing microorganism is added, one or more times, to the biogas producing consortium.

3. The method of claim 1, wherein the thermophilic, anaerobic, acetogenic, hydrogen producing bacterium belongs to the Thermotoga, Thermococcus, Pyrococcus, Clostridium, Ruminococcus or to the Caldicellulosiruptor genus.

4. The method of claim 3 wherein the thermophilic, anaerobic, acetogenic, hydrogen producing bacterium is Caldicellulosiruptor saccharolyticus.

5. The method of claim 4 wherein a pure culture of Caldicellulosiruptor saccharolyticus is used.

6. The method of claim 1 wherein the biomass is

liquid manure,

waste water sludge or

plant waste, preferably plant waste from high energy plants

or any mixture thereof.

7. The method of claim 1 wherein before of during fermentation an additive, preferably a material utilizable as a nutrient by any of the microorganisms and/or a material of increased surface area

is added to the biomass.

8. The method of claim 7 wherein the cells of the hydrogen producer bacterium are sedimented or are bound to a carrier, preferably high specific surface, inert carrier e.g. perlite.

9. The method of claim 1 wherein the bacterium culture is applied, relative to the volume of the biomass, in a ratio of 5 to 20 v/v %, preferably 10 v/v %.

10. The method of claim 1, wherein the biomass is fermented in a fermentor having a single reactor vessel or a single reactor space.

11. The method of claim 10 wherein the biomass is fermented in a continuous operation system, wherein

the produced biogas and or the produced fermented biomass is removed continuously or at multiple times, preferably at given periods of time, and

the thermophilic, anaerobic, acetogenic, hydrogen producing bacterium is fed continuously or at multiple times, preferably at given periods of time, to the fermentor.

12. The method of claim 1 wherein the bacterium has a polymer degrading, preferably a carbohydrate degrading activity.

25. The method of claim 1, comprising the steps of

starting the fermentation of the biomass by setting its temperature to 45-70°

C., preferably to 50-60°

C., and optionally inoculating the biomass by an inoculum comprising polymer-degrading microorganisms, acetogenic microorganisms and/or methanogenic microorganisms

providing anaerobic conditions to the fermentation,

before the start of the fermentation or during fermentation, inoculating the biogas producing system by a culture of thermophilic, anaerobic, acetogenic, hydrogen-producing bacterium,

carrying on the fermentation at 45-70°

C., preferably at 50-60°

C., under anaerobic conditions,

collecting or utilizing the produced methane-containing biogas.

13-24. -24. (canceled)