1. Anaerobic Digestion: Biomass to Bioenergy Douglas W. Hamilton, Ph.D., P.E. Associate Professor, Biosystems and Agricultural Engineering Waste Management Specialist, Oklahoma Cooperative Extension Service

2. Anaerobic Digestion of Manure  Understanding Basic Processes

3. Digestion Process CH 4 CO 2 H 2 NH 3 H 2 S + Biogas

4. Acid Formers Methane Formers Liquifiers

5. Acid Formers Methanogens Hydrolizers

6. Community Needs 1.Food 2.Proper pH 3.Sufficient Temperature 4.Sufficient Time to Reproduce 5.Absence of Inhibitory Substances

7. Community Needs Proper pH : ~ 6.5 to 7.5

8. Community Needs Sufficient Temperature Psychrophilic (15-25 o C) Mesophilic (30-38 o C) Thermophilic (50-60 o C)

9. Community Needs Sufficient time to reproduce

11. HRT = Volume of Reactor/Flow out

12. SRT = Solids in Reactor/Solids Leaving

13. Anaerobic Digestion of Manure  Understanding Basic Processes  Types of Reactors

14. Low Rate Reactor SRT = HRT

15. High Rate Reactor SRT > HRT

16. How much energy?

17. Anaerobic Digestion of Manure  Understanding Basic Processes  Types of Reactors  Organic Matter of Wastewater and Manure  Methane Production Potential  Toxic and Inhibitory Materials

18. Codigestion Mixing a highly digestible material with a source of microorganisms (manure) to produce a large volume of biogas.

19. Methane Potential  Volatile Solids Content

20. Combustion OM + O 2 → CO 2 + H 2 O + Ash + Heat

21. Combustion OM + O 2 → CO 2 + H 2 O + Ash + Heat TS FS

22. Combustion OM + O 2 → CO 2 + H 2 O + Ash + Heat TS FS VS

23. VS db % Beef Manure82 Dairy Manure84 Wood Shavings99 Alfalfa Silage95 Grease99

24. Aerobic Catabolism OM + O 2 → CO 2 + H 2 O + Cells + Heat

25. Aerobic Catabolism OM + O 2 → CO 2 + H 2 O + Cells + Heat Oxygen Demand

26. Aerobic Catabolism OM + O 2 → CO 2 + H 2 O + Cells + Heat Oxygen Demand COD BOD u

27. Methane Potential  Volatile Solids Content  COD

28. Anaerobic Catabolism OM + Heat → CH 4 + CO 2 + H 2 O + Cells

29. Anaerobic Catabolism OM + Heat → CH 4 + CO 2 + H 2 O + Cells Biogas

30. Combustion OM + Heat → CH 4 + CO 2 + H 2 O + Cells CH 4 + 2O 2 → CO 2 + H 2 O + Heat

31. Combustion OM + Heat → CH 4 + CO 2 + H 2 O + Cells CH 4 + 2O 2 → CO 2 + H 2 O + Heat Oxygen Demand

32. Combustion CH 4 +2O 2 → CO 2 + H 2 O + Heat Two moles O 2 per mole CH 4

33. Combustion CH 4 +2O 2 → CO 2 + H 2 O + Heat 2n OD = n CH4

34. Combustion CH 4 +2O 2 → CO 2 + H 2 O + Heat PV = nRT

35. Combustion CH 4 +2O 2 → CO 2 + H 2 O + Heat V CH4 = 2n OD RT/P

36. Ultimate Gas Yield CH 4 +2O 2 → CO 2 + H 2 O + Heat 0.38 L CH 4 produced per kg OD removed @ 20 o C and 1 atm

37. VS db % COD:VS Beef Manure821.2 Dairy Manure841.2 Wood Shavings99 0.19 Alfalfa Silage95 0.70 Grease99 0.40

38. Methane Potential  Volatile Solids Content  COD  BMP

39. BMP Biochemical Methane Potential www.bioprocess.com

40. D.P. Chynoweth www.agen.ufl.edu

41. VS db % COD:VS COD converted to CH 4 % Beef Manure821.217 Dairy Manure841.255 Wood Shavings99 0.1933 Alfalfa Silage95 0.70110 Grease990.4052

42. D.P. Chynoweth www.agen.ufl.edu Specific Methane Yield (L CH 4 g -1 VS)

43. VS db % COD:VS COD converted to CH 4 % Specific Methane Yield L CH 4 g -1 VS Beef Manure821.2 17 0.084 Dairy Manure841.2 550.24 Wood Shavings99 0.19 33 0.067 Alfalfa Silage95 0.70110 0.30 Grease99 0.40 52 0.81

44. Community Needs 1.Food 2.Proper pH 3.Sufficient Temperature 4.Sufficient Time to Reproduce 5.Absence of Inhibitory Substances

45. Methane Potential  Volatile Solids Content  COD  BMP  ATA

46. ATA Anaerobic Toxicity Assay

47. Inhibition (%) I = (1 - Pt/Pc) X 100 Where: Pc = gas produced 0% inclusion Pt = gas produced at test inclusion

48. ATA Anaerobic Toxicity Assay

49. Methane Potential  Volatile Solids Content  COD  BMP  ATA  Pilot Testing

50. Pilot Scale Testing

51. B o S o θ v 1 - K µ m θ s – 1 + K VRE = Chen, Y.R. and A.G. Hashimoto. 1980. Substrate utilization kinetic model for biological treatment processes. Biotech &. Bioeng. 22:2081-2095

52. Any Questions?