Integrated waste reduction system
AssigneeBlack & Veatch Holding Company
InventorSandeep Sathyamoorthy
Life of this patent
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Abstract
A waste reduction system that utilizes organic solids suspended in a waste stream to produce carboxylic acids, which can then be employed as an input to a microbial fuel cell or other biological processes to further enhance biogas production, is provided. The organic waste stream influent undergoes a multistage fermentation process in which fermentative microorganism metabolize the organic waste materials and produce one or more carboxylic acids, especially short chain fatty acids. The carboxylic acids serve as a food source for bacteria within an anode compartment of an MFC that generates useable electricity therefrom.
Claims24
A system for treating an organic waste feedstock comprising:
- (a) a first fermentation vessel comprising:
- a waste stream inlet configured to direct the organic waste feedstock into the first fermentation vessel,
- an upflow tube having a lower tube inlet and an upper tube outlet,
- a liquid circulation device configured to cause the organic waste feedstock to enter the upflow tube at the lower tube inlet and exit the upflow tube at the upper tube outlet,
- a first fermentation vessel outlet;
- and
- one or more species of microorganisms that ferment an organic material contained within the organic waste feedstock and produce one or more carboxylic acids;
- and
- (b) a second fermentation vessel comprising:
- a second fermentation vessel inlet configured to receive an organic waste stream from the first fermentation vessel and introduce the organic waste stream into the second fermentation vessel,
- a second fermentation vessel outlet;
- and
- one or more species of microorganisms, which can be the same or different from the one or more species of microorganisms present within the first fermentation vessel, that ferment the organic material contained within the organic waste stream to produce one or more carboxylic acids, which can be the same or different from the one or more carboxylic acids produced within the first fermentation vessel.
A fermentation vessel for fermenting organic material contained within an organic waste feedstock comprising:
- a waste stream inlet configured to direct the organic waste feedstock into the fermentation vessel;
- an upflow tube having a lower tube inlet and an upper tube outlet, the waste stream inlet introducing the organic waste feedstock directly into the upflow tube at a point in between the lower tube inlet and the upper tube outlet;
- a liquid circulation device located within the upflow tube configured to cause the intake of a liquid fermentation media being circulated within the fermentation vessel through the lower tube inlet and expel the liquid fermentation media through the upper tube outlet;
- an upflow transition zone disposed laterally from the upflow tube configured to conduct the liquid fermentation media between a lower transition zone inlet toward an upper transition zone outlet;
- and
- a waste stream outlet connected to the upflow transition zone and configured to direct the liquid fermentation media out of the fermentation vessel.
A fermentation vessel for fermenting organic material contained in a liquid waste stream comprising:
- a waste stream inlet located in an upper half of the fermentation vessel and configured to direct the liquid waste stream into the fermentation vessel;
- a feed tube extending from the waste stream inlet and having an opening communicating the feed tube with an interior of the fermentation vessel, the opening being located within the lower half of the second fermentation vessel;
- an agitating device located within the interior of the fermentation vessel and configured for continuous or intermittent operation to stir a liquid fermentation media contained within the fermentation vessel, the liquid fermentation media comprising the liquid waste stream introduced into the fermentation vessel through the waste stream inlet;
- and
- a vertical duct comprising a first passage extending between the bottom of the fermentation vessel and a vessel outlet located in the upper half of the fermentation vessel configured to direct a portion of the liquid fermentation media upward toward a vessel outlet.
Dependencies are inferred from the claim text.