Systems and processes for treatment of organic waste materials with a biomixer

Abstract

Waste material is screened to produce unders and overs, the overs are treated to produce a partially hydrolyzed biomass, and the partially hydrolyzed biomass and the unders are anaerobically digested. Treating the overs includes fermenting and mixing the overs with an aerotolerant anaerobic bacteria in a controlled environment, such as a rotating drum, while air is passed through the controlled environment. The moisture content, pH, and biological content of the overs can be adjusted before the overs are treated. Volatile fatty acids from the air passed through the controlled environment can be collected for anaerobic digestion or can be recirculated back into the controlled environment. The cleansed air can also be recycled back into the controlled environment.

Description

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a symbolic diagram of an organic waste treatment system in accordance with an embodiment of the invention.

FIG. 2 is a symbolic longitudinal cross-sectional view of the flexible hydrolysis vessel of the system of FIG. 1.

FIG. 3 is a flowchart depicting a process for treating organic waste material, in accordance with an embodiment of the invention.

FIG. 4 is a symbolic side view of an apparatus for static reverse air composting, in accordance with a specific implementation of the invention.

FIG. 5 is a flow diagram of a process for treating waste material in accordance with a specific implementation of the invention.

FIG. 6 depicts major components of an organic waste treatment system in accordance with a specific implementation of the invention.

FIG. 7 is a flow diagram of a process for treating waste material in accordance with another implementation of the invention.

FIG. 8 depicts a biomixer in accordance with another specific implementation of the invention.

Claims

1. A process for treating waste material, comprising: screening the waste material to produce unders and overs thereof;treating, by fermenting and mixing, the overs of the waste material with an aerotolerant anaerobic bacteria in a controlled environment to produce a partially hydrolyzed biomass;passing air through the controlled environment while treating the overs therein; andanaerobically digesting the unders of the waste material and the partially hydrolyzed biomass.

2. The process of claim 1 wherein the waste material comprises a source separated organic waste.

3. The process of claim 1 wherein the waste material comprises municipal solid waste.

4. The process of claim 1 wherein the controlled environment includes a rotating drum.

5. The process of claim 1 further comprising sorting the waste material prior to screening the waste material.

6. The process of claim 1 further comprising sorting the overs after screening the waste material.

7. The process of claim 1 further comprising screening the partially hydrolyzed biomass to produce unders and overs thereof, and anaerobically digesting the unders of the partially hydrolyzed biomass.

8. The process of claim 7 further comprising sorting the overs of the partially hydrolyzed biomass.

9. The process of claim 1 further comprising adjusting a moisture content of the overs of the waste material before treating the overs in the controlled environment.

10. The process of claim 1 further comprising adjusting a pH of the overs of the waste material before treating the overs in the controlled environment.

11. The process of claim 1 further comprising adjusting a biological content of the overs, before treating the overs in the controlled environment, by adding a portion of the partially hydrolyzed biomass to the overs.

12. The process of claim 1 further comprising recovering volatile fatty acids from the air passed through the controlled environment.

13. The process of claim 12 wherein treating the overs in the controlled environment includes adding water, containing the recovered volatile fatty acids, into the controlled environment.

14. The process of claim 12 further comprising anaerobically digesting the recovered volatile fatty acids.

15. The process of claim 12 wherein recovering the volatile fatty acids includes scrubbing the air with water to cleanse the air and to concentrate the volatile fatty acids in the water.

16. The process of claim 15 wherein passing air through the controlled environment includes recycling the cleansed air into the controlled environment.

17. A process for treating waste material, comprising: screening the waste material to produce unders and overs thereof;treating, by fermenting and mixing, the overs of the waste material with an aerotolerant anaerobic bacteria in a controlled environment to produce a partially hydrolyzed biomass;passing air through the controlled environment while treating the overs therein; andrecovering volatile fatty acids from the air passed through the controlled environment.

18. The process of claim 17 wherein recovering the volatile fatty acids includes scrubbing the air with water to cleanse the air and to concentrate the volatile fatty acids in the water.

19. The process of claim 18 wherein passing air through the controlled environment includes recycling the cleansed air into the controlled environment.

20. A system for treating waste material, comprising: a screening device for separating the waste material into unders and overs thereof;a rotatable drum, sloped relative to the horizontal, and configured to receive the overs from the screening device and to mix the overs with an aerotolerant anaerobic bacteria to produce a partially hydrolyzed biomass; andan air system including an air injector configured to inject air into a discharge end of the drum; andan air collection device configured to receive the air from a feed end of the drum.

21. The system of claim 20 wherein the screening device comprises a trommel.

22. The system of claim 20 wherein the aerotolerant anaerobic bacteria comprise a species of a genera selected from the group consisting of Desulfomonas, Butyrivibrio, Eubacterium, Lactobacillus, Clostridium or Ruminococcus.

23. The system of claim 20 further comprising an infeed system configured to load the overs from the screening device into the drum.

24. The system of claim 20 further comprising a water scrubbing system configured to receive the air from the air collection device and to cleanse the air with water.

25. The system of claim 24 wherein the air injector is configured to receive the cleansed air from the water scrubbing system and inject the cleansed air into the drum.

26. The system of claim 24 further comprising an infeed system configured to load the overs from the screening device into the drum, and further configured to receive water from the water scrubbing system and to mix the water into the overs.