1. Assessing Project Feasibility System Stability using AQUASIM Claire Allen March 10, 2009 Canadian Farm and Food Biogas Conference and Exhibition

2. Outline Project Feasibility (substrates) AQUASIM – Why use a computer model? – Matching program to lab data Case Studies – Manure & FOG – Stillage only – Manure & Potatoes Conclusion – Biogas isn’t just for farms! – AQUASIM is a useful tool to reduce costs

3. Project Feasibility The following factors are considered when analyzing project feasibility: – Farm Profile – Grid Connection – Economic Factors – System Stability

4. System Stability: Co-digestion Co-digestion refers to the use of off-farm materials in a biogas system Co-digestion can increase: – biogas production and energy yields – economic yields Co-digestion can potentially decrease overall system stability A wide variety of organic wastes are suitable for digestion

5. System Stability: Energy Yields Cow manure yields ~ 40 m 3 biogas/ton Typical co-substrates – Fats, Oil, Grease (FOG) yields 200-400 m 3 biogas/ton – Source Separated Organics yields 100-300 m 3 biogas/ton Anaerobic digestion as waste management in more than just the farming industry

7. Addition of Co-Substrates How do you know the co-substrates will function in a digester? – Build a digester and cross your fingers – Lab tests – Literature Research – Computer Modelling

8. AQUASIM A computer program designed to identify and simulate aquatic systems IWA Task Group for Mathematical Modeling of Anaerobic Digestion Processes – Anaerobic Digestion Model (ADM) – Activated Sludge Model (ASM) Model has been calibrated with field and lab data

9. Cow Manure & FOG Typical digester set-up Experimental data from a client – 15 m 3 /day manure – 3 m 3 /day FOG – Our model matches initial data but we still have some analysis to do

10. Manure & FOG pH 500 m 3 digester 15 m 3 manure/day 3 m 3 FOG/day pH 7.4

11. Manure & FOG Biogas 1100 m 3 biogas/day manure only: 460 m 3 biogas/day

12. Manure & FOG COD 6 kgCOD/m 3 45 kgCOD/m 3

13. Manure & FOG Acid 260 mg/L

14. Manure & FOG Overload pH 7

15. Stillage

16. Stillage - pH pH was adjusted after 60 days

17. Stillage Biogas

18. Stillage - TCOD and SCOD

19. Manure & Potatoes This case study includes: – Dairy Manure: 3000 m 3 /day – Potatoes: 5500 m 3 /day – Starch: 1000 m 3 /day – Secondary Cake: 8000 m 3 /day – Grease: 150 m 3 /day System that is high in carbohydrates, must be careful with pH

20. Manure & Potato pH pH 7.4

21. Manure & Potato Biogas 3250 m 3 biogas/day

22. Manure & Potato Biogas

23. Manure & Potato Acid 70 mg/L

24. Conclusion System stability is a vital part of overall project feasibility The use of a computer model allows us to analyze possible system digester configurations

25. QUESTIONS? CH-Four Biogas Inc. 107-1390 Prince of Wales Dr. Ottawa, ON K2C 3N6 T: 613 224 8308 F: 613 224 1642 info@chfour.ca www.chfour.ca