Municipal Project Development Considerations. Mike Muffels MSc P.Eng. March 22, 2018

Transcription

1 Municipal Project Development Considerations Mike Muffels MSc P.Eng. March 22, 2018

2 Introduction and outline Landfill Gas 1. Feedstock Biogas Biomethane (RNG) WWTP Sludges Pre-Consumer Food Waste Post Consumer Food Waste Leaf & Yard Waste 2. Anaerobic Digestion 3. Biogas Upgrading 4. Siting 5. Procurement Strategy Value of Biogas East Conference March 22, 2018

3 Feedstock considerations

4 Feedstock considerations Process must be designed for the feedstock Collection program and AD facility must be planned together Low solids High solids De-packaging Pre-processing Value of Biogas East Conference March 22, 2018

5 Single vs. multi-family Single detached homes are on the decline in urban areas More recyclable/organic material moving to a harder to capture housing market Higher levels of contamination Participation levels may be low Retrofits required Some older buildings may be exempt from future source separation programs Existing traffic congestion

6 Mixed Waste Processing (MWP) in Organics Framework In addition to curbside collection of source separated food and organic waste, MWP may be used recover additional food and organic waste Provided recovered organics meet existing regulations BUT there are none that address organics recovered from garbage MWP is common in Europe BUT recovery of organics is not a MUST in Ontario: process and permitting challenge TREND: Three municipalities in ON investigating feasibility of MWP Black bins still contained 40% organics Study recovered and digested organics from mixed waste Processed with IC&I and residential SSO Further study and development required (and planned)

7 Basics of anaerobic digestion Biologic degradation of materials in the absence of oxygen Used in both treatment of WWTP sludges and food waste Produces a biogas Produces digestate Beneficial use of digestate Further treatment required? Storage considerations Produces residue Requires disposal or to energy-from-waste Potentially produces wastewater Significant capital and operating burden WWTP Sludge/ Food Waste Wastewater Green Energy Opportunities Residue Biogas Digestate Beneficial Use

8 Opportunities to utilize existing assets and resources? Solid waste industry looking to increase diversion of food waste Wastewater industry seeking to minimize energy consumption and operating costs at WWTPs Can we take food waste out of the landfill and use it to minimize energy consumption and operating costs at a WWTP? Food Waste Diversion Reduced WWTP O&M Co-digestion INCREASED SUSTAINABILITY

9 Potential benefits of co-digestion On-site digester operating expertise at WWTPs WWTPs located in urban areas where food waste is generated: Reduced transportation costs Reduced site development costs for new waste processing facility Increased volatile solids destruction, reducing biosolids volumes and management costs Green Energy Opportunities Digesting food waste prior to composting reduces emissions of volatile organic compounds (VOCs), which contribute to air pollution

10 Energy use at WWTPs Water and wastewater utilities are typically the largest energy consumers in municipalities, often accounting for 30-40% of total energy consumed by municipal governments For WWTPs, energy bills can be ~30% of total operation and maintenance (O&M) costs, usually representing a facility s second or third biggest expense Source: EPA/600/R-14/240 September 2014

11 Potential challenges Physical contamination in food waste grit and solids accumulation in digesters, biosolids quality Limit to how much food waste can be added (approx. 20%) Foaming and sludge blanket formation Hydrogen sulfide (H 2 S) odor and corrosion concerns

12 Garbage disposals Potential opportunity to further reduce transportation costs and increase food waste capture from multi-family Further pre-processing would not be required at WWTP Wastewater collection infrastructure needs to be evaluated to be sure it can accommodate the ground-up food waste

13 Biogas upgrading considerations RNG must provide more revenue to the AD project than a base case that does not require expensive biogas upgrading Example: using all biogas in a boiler to displace NG = >$8/GJ revenue Available grants make ON: Municipal GHG Challenge Fund (100% of capex up to $10 million) Fed: Low Carbon Economy Challenge Fund (40% up to $50 million) Understand the average and peak flows and quality of biogas Consult with utility to determine injection feasibility and requirements Understand the nomination process and the consequences when actual production differs from nominated volume How often will difference need to be balanced? Daily, monthly yearly? Value of Biogas East Conference March 22, 2018

14 Siting RNG Injection Location Ideally within 100m of suitable injection location Nearby to ultimate compressed RNG customer Zoning Rezoning adds to project length, costs, and risks Some by-laws may prohibit storage of methane Odour Minimize process air requiring treatment Model impact to nearest sensitive receptor Traffic Improvements to local roads required? Traffic impacts to neighbours common complaint

15 Procurement strategy DBB DB DBO BOOT Increasing private sector involvement BOO Budget MIN MAX Schedule Design Admin. Control Risk MAX MAX MAX MAX MAX MIN MIN MIN MIN MIN Value of Biogas East Conference March 22, 2018

16 Questions

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