Method and apparatus for membrane-based, two-stage gas production from solid biomaterials
Embodiments of the present invention preferably relate to a method and apparatus for a two-stage membrane-based production of gas, preferably hydrogen gas or the like, from solid biological materials, preferably organic waste materials or the like, comprising anaerobic hydrolysis and fermentation and photofermentation using microorganisms.
1. A method for producing gas from a biomaterial comprising the steps of:
fermenting the biomaterial using anaerobic hydrolysis-fermentation;
photofermentating;
removing the gas;
maintaining a pH during at least one stage of the method;
the anaerobic hydrolysis-fermentation and the photofermentating take place in a single vessel comprising a multi-stage reactor and a gas-specific membrane;
the multi-stage reactor comprising at least one leach-bed reactor and at least one suspended-growth reactor, the suspended-growth reactor in fluid communication with the leach-bed reactor; and
the single vessel comprising a plurality of tubes, wherein a portion of the tubes divide the leach-bed reactor from the suspended-growth reactor within the single vessel, and an annular space between the tubes dividing the leach-bed reactor from the suspended-growth reactor.
2. The method of claim 1 wherein the anaerobic hydrolysis-fermentation and photofermentating occur in series.
3. The method of claim 1 wherein the anaerobic hydrolysis-fermentation comprises percolating leachate in a cross-flow mode.
4. The method of claim 1 wherein the anaerobic hydrolysis-fermentation comprises anaerobically fermenting leachate to produce a mixture comprising hydrogen gas, carbon dioxide, and fatty acids.
5. The method of claim 1 wherein the photofermentating comprises converting fatty acids to produce a mixture comprising hydrogen, carbon dioxide, and organic residue.
6. The method of claim 1 wherein the anaerobic hydrolysis-fermentation and photofermentating occur at room temperature.
7. The method of claim 1 wherein maintaining the pH comprises monitoring and controlling different pH levels in different stages.
8. The method of claim 1 further comprising maintaining hydrogen partial pressure and avoiding product inhibition.
9. The method of claim 1 wherein the anaerobic hydrolysis-fermentation occurs in a leach-bed reactor.
10. The method of claim 1 wherein the photofermentating occurs in a suspended-growth reactor stage.
11. The method of claim 1 wherein the biomaterial is a solid.
12. The method of claim 1 wherein the anaerobic hydrolysis-fermentation and photofermentating comprise utilizing naturally occurring organisms.
13. The method of claim 12 wherein the naturally occurring organisms occur in manure.