1. Co-digestion... Can it Work?
Peter Klaassen
VP Solid Waste Ontario

2. Presentation Overview
Tetra Tech
Definition of Co-Digestion
Regulatory Environment
Technical Overview

3. TetraTech Profile Multi Disciplined Consultants
Offices in Canada, US, GB, Australia and South America
18,000 employees worldwide, 3000 in Canada
175 Waste Professionals in organization

4. Areas of Expertise General Engineering Infrastructure Power
Transportation
Waste Management

5. Waste Management Practice Areas
Planning
Design
Site Investigation
Construction

7. What is Co-Digestion?
Mixing of the Organic Fraction of Solid Waste with Sewage Waste with the primary purpose of generating more methane in the digestion process.

8. Why Co-Digestate? Numerous bio-solid (sewage) facilities in existence
Low Solids digestion attains higher yields of methane (RNG) production
Regulatory Environment favours methane production

9. Regulatory Environment
Ontario
Bill 151 Waste Free Ontario Act
Cap and Trade/Carbon Tax
Green Fuel Initiatives
Federal
Carbon Tax or Equivalent

10. Issues
Municipal Sewage Treatment is typically handled by different group from Solid Waste
Capital Cost can be high
Is there capacity to Co-Digestate
Stabilized Digestate needs Destination
Odour Control

11. SSO or ICI High/Low Solids Waste Pretreated Bio-Solid Waste
The Process
RNG
SSO or ICI High/Low Solids Waste
Pre-Treatment
Biogas
Pretreated Bio-Solid Waste
Mixing
Digestion
Digestate

12. RNG What is RNG Cleaning to remove Co2 and other compounds
Injection into pipeline – compression and addition of mercaptan
CNG use for fuel
Use as energy source (electrical/ thermal)

13. RNG
In Ontario both Union and Enbridge have indicated that they want higher amounts of RNG in their pipelines
Green Fuel initiatives may favour having municipal fleets powered by Natural Gas supplemented with RNG

14. Digestors Capacity Mesophylic versus Thermophylic Digestion
Improving quality of Stabilized Digestate

15. Case Study - Kingston Population 125,000 Two sewage treatment plants
Goal – increase gas production through various enhancements
Addition of SSO
Enhancement of finished digestate

16. Case Study - Kingston
Kingston – Sewage plants connected to Union Gas but have own gas distribution systems
Tight real estate – will need to look at traffic flow, tipping area and pre-processing

17. Case Study - Kingston
Outcome – 30 to 60 % increase in gas production with addition of 4000 tpy SSO
Can be scaled to other municipalities
1000 tpy generates
250 m3 methane per day
8 GJ methane per day

18. Case Study - Kingston
Next steps – proforma evaluation of enhancements plus SSO
Analysis will include capital costs and changes in revenues and costs
Revenues may include:
Tipping fees
Price of gas
Carbon credits

19. What is RNG worth? Dependent on location and Carbon Mechanisms
RNG vs CNG
Wheeling

20. Kingston – Conclusions to Date
Revenue is extremely important
Cost to clean gas is expensive
RNG is going up in value
Where is nearest pipeline (end of line?)
Complex Analysis

21. Going forward Election, party platforms
Provincial and Federal grant programs

22. Peter Klaassen Peter.Klaassen@tetratech.com