Organic waste material treatment system
A multi-stage process and system for treating organic waste materials includes steps of hydrolyzing the materials in an anaerobic vessel, transferring the liquid product of hydrolysis to an anaerobic digester, and further decomposing the waste materials under aerobic conditions to yield a compost product usable as a soil amendment. Biogas produced by digestion of the hydrolysis liquid product may be burned to generate electricity or heat, and the liquid digester product may be recirculated for use as an inoculant to aid hydrolysis of subsequently processed batches of waste materials.
1. A system for treating organic waste material, comprising:
a flexible vessel, capable of being sealed, for containing a volume of organic waste material during hydrolysis thereof, said flexible vessel having a longitudinal axis extending from a first portion at a first end of the vessel to a second portion at a second end of the vessel, the vessel sloped along the longitudinal axis such that the first portion is positioned lower than the second portion such that a liquid hydrolysis product flows under the influence of gravity toward the first end portion of the vessel;
at least one conduit communicating at one end thereof with the interior of the flexible vessel, at said first end for removing the liquid hydrolysis product from the flexible vessel; and
a digester, coupled the other end of to the at least one conduit, for anaerobically digesting the liquid hydrolysis product from the flexible vessel to produce a biogas product and a liquid digester product.
2. The system of claim 1 , wherein the flexible vessel is cylindrical having first and second end portions.
3. The system of claim 1 , wherein at least one end portion is initially open to enable the addition of the organic waste material, and is subsequently closed to seal the vessel.
4. The system of claim 2 , wherein the flexible vessel has walls formed from a polymer material.
5. The system of claim 1 , wherein the at least one conduit communicates with the interior of the flexible vessel through a port located proximal to the first end portion.
6. The system of claim 1 , wherein the flexible vessel has a port for coupling the vessel to the at least one conduit, the port including a valve operable to selectively allow or inhibit the transfer of hydrolysis liquid product into the conduit.
7. The system of claim 1 , further comprising a holding tank, coupled to the at least one conduit, for storing the liquid hydrolysis product prior to transfer to the digester.
8. The system of claim 1 , further comprising an electrical generator for burning the biogas product to produce electricity.
9. The system of claim 1 , further comprising a heat exchanger for transferring thermal energy produced by combustion of the biogas product to the digester.
10. The system of claim 1 , further comprising a perforated pipe situated within the interior of the flexible vessel for facilitating flow of the liquid hydrolysis product into the first end portion.