Syntrophic enrichment for enhanced digestion process
AssigneesMetro Vancouver Regional District, Greater Vancouver Sewerage & Drainage District
InventorsPaul Kadota, Paul Markin, Cigdem Eskicioglu
Life of this patent
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Abstract
A syntrophic enrichment for enhanced digestion (SEED) system is presented, in which a retrofit addition to existing anaerobic digestion infrastructure provides improved digestion process rate and biogas quality. The system provides optimal niche environments for accelerating fermentative, syntrophic and methanogenic metabolisms to increase digestion system loading rates and enhance main digester microbiome. Prescribed media formulations, reactor integrations, and operational methods using various fixed and loose media enhance global digestion system performance. The retrofitted system enables existing plants to transition from an outdated solids-management model to one of valorized biomethane production.
Claims22
A bioreactor in an anaerobic digestion system for treating wastewater, the bioreactor comprising:
- an enclosed cylinder comprising:
- a central draft tube;
- a main annular space surrounding the central draft tube;
- an electroactive medium in a fixed configuration dispersed within the enclosed cylinder;
- an inlet for introducing a feedstock into the enclosed cylinder in contact with the electroactive medium;
- and
- an outlet for outputting the feedstock after treatment.
A bioreactor in an anaerobic digestion system for treating wastewater, the bioreactor comprising:
- an enclosed cylinder comprising:
- a central draft tube;
- a main annular space surrounding the central draft tube;
- a loose electroactive medium dispersed within the enclosed cylinder and contained within a porous receptacle,
- an inlet for introducing a feedstock into the enclosed cylinder in contact with the electroactive medium;
- and
- an outlet for outputting the feedstock after treatment.
A bioreactor in an anaerobic digestion system for treating wastewater, the bioreactor comprising:
- an enclosed cylinder comprising:
- a central draft tube;
- a main annular space surrounding the central draft tube;
- a loose electroactive medium dispersed within the enclosed cylinder;
- a replaceable container to contain the loose electroactive medium in a second annular space defined by the central draft tube and the replaceable container;
- an inlet for introducing a feedstock into the enclosed cylinder in contact with the electroactive medium;
- and
- an outlet for outputting the feedstock after treatment.
A method of treating wastewater in an anaerobic digestion system, the method comprising:
- introducing a feedstock comprising a sufficient concentration of organics derived from the wastewater into a bioreactor;
- circulating the feedstock in contact with an electroactive medium dispersed inside the bioreactor;
- growing a biofilm from the feedstock, a methanogen, and a syntrophic bacterium on the electroactive medium;
- converting the organics into a biogas within the anaerobic digestion system;
- back injecting a fraction of the biogas or an externally-generated hydrogen into the bioreactor for mixing, purification, or amelioration of methane production;
- scouring the biofilm from the electroactive medium by a liquid shear force of the feedstock, and/or biogas injection;
- and
- dosing a biocatalyst comprising the biofilm and/or an electron-conductive supplement into a main anaerobic digester downstream of the bioreactor,
- thereby increasing a methane content in the biogas and increasing digestion system capacity.
Dependencies are inferred from the claim text.