Biosolids Planning – Core Team Meeting

1. City of Bellingham Biosolids Planning – Core Team Meeting March 6, 2017

2. Safety Minute Grilling Safety: Get ready for spring grilling with these safety reminders

3. Statistics • 7,000 Americans are injured in outdoor grilling accidents each year • 71% of all grill fires are residential (others include campsites, businesses, etc.) • The majority of grilling accidents involve alcohol Subtitle is Arial

4. DON’T: Turn on the gas when the grill lid is closed Gas can build up and cause a explosion/fire ball when lit Leave the grill unattended Prep and plan before you start grilling Try to cook too many things at once Fatty foods can cause flare ups Use your grill indoors Fire and carbon monoxide hazard Do’s and Don’ts DO: Keep your grill at least 10 feet away from standing structures Houses, carports, garages, porches Clean your grill often Built up fat and grease can provide fuel for a fire Keep decorations away from your grill Streamers, umbrellas, hanging baskets Keep a Fire Extinguisher nearby And know how to use it

5. Agenda Brown and Caldwell

6. Brown and Caldwell

7. Confirm Selection Criteria Confirm updates to pass/fail Communicate changes to TBL Brown and Caldwell

8. Confirm Selection Criteria Brown and Caldwell

9. Overview of World of Alternatives Solids Stabilization Beneficial End Use Biogas End Use Brown and Caldwell

10. Solids Stabilization Technologies Brown and Caldwell

11. Anaerobic Digestion • Biological decomposition of solids under anaerobic conditions • Mesophilic and thermophilic temperatures (95-135 degF) • Reduces volatile solids and pathogens suitable for land application • Produces methane-rich biogas Brown and Caldwell

12. Thermal Hydrolysis (THP) + Anaerobic Digestion • Pre-processing before anaerobic digestion, breaks down cell walls to improve decomposition • Improves pathogen reduction – produces Class A biosolids • Requires both pre-THP dewatering and post-digestion dewatering • Requires high-temperature steam (90 psi, 320oF) Brown and Caldwell

13. Aerobic Digestion • Open to atmosphere, requires energy intensive aeration • Reduces volatile solids and pathogens • No biogas production Brown and Caldwell

14. Lagoons • Very large land intensive ponds • slow decomposition of organic matter • Require dredging to remove settled solids • 4-8 feet deep, aerobic and anaerobic zones • Very low energy consumption • Odorous and no biogas/energy recovery • Large GHG emission Brown and Caldwell

15. Alkaline Stabilization • Addition of alkaline chemical (e.g., lime) to raise pH above 12 • Achieves stabilization faster than anaerobic digestion • No reduction in solids (actually increases solids) • No recovery of biogas/energy • Very odorous Lime-stabilized biosolids (left) compared to anaerobically digester solids (right) Brown and Caldwell

16. Raw Solids Composting • Decomposition of organic material, can achieve pathogen reduction • Process requires mixing and/or aeration • Requires additional organic material to be added to solids • No reduction in solids (actually increases solids) and no recovery of biogas/energy • Very odorous Brown and Caldwell

17. Incineration • Destruction of solids to produce ash • Can be autogenous with very little fuel input • Can recover energy from exhaust to generate power Brown and Caldwell

18. Gasification • Low-oxygen combustion of solids (sub-stochiometric) • 1500-1800 degF • Requires dried biosolids and supplemental feedstock (e.g. wood chips, tires) for reliable operation • Produces char and low-Btu syngas (requires treatment before combusting) that is used to dry the solids Brown and Caldwell

19. Pyrolysis • Anaerobic (starved-air) combustion of solids • 750-1,100 deg F • Requires dried biosolids as feedstock • Produces char and bio-oil that requires refining before use as a vehicle fuel Brown and Caldwell

20. Hydrothermal Liquefaction • High temperature (700oF), high pressure (3,000 psi) process • Uses dewatered raw solids as feedstock • Produces bio-oil that needs further refining before using as a vehicle fuel Brown and Caldwell

21. Supercritical Water Oxidation • High temperature (1,100 degF), high pressure (3,600 psi) process • Uses water in the feed as a solvent • Above water’s critical point organics become soluble and inorganics become insoluble • Can recover heat from the oxidation process to produce steam Brown and Caldwell

22. Primary Biosolids End Use Alternatives Brown and Caldwell

23. Land Application • Can be applied to farmland, forests, and/or mine reclamation • Class A or Class B biosolids • Supports plant growth, recovery of soil tilth, and carbon sequestration Brown and Caldwell

24. Soil Amendment • Addition of sand and sawdust (or other organic bulking agent) to create a topsoil amendment (similar to TAGRO); requires Class A digestion • Composting of digested solids with other organic material (similar to GroCo); can produce Class A during composting • Must be Class A biosolids product if sold to the public • Used for gardening, etc. Brown and Caldwell

25. Dried Product • Dried to a Class A product • Can be used as a fertilizer sold in bags or in bulk (e.g., SoundGro) • Can be used as a fuel to offset non-renewable fuel use (e.g., coal at a cement kiln) Brown and Caldwell

26. Landfill • Can be used as backup disposal method • Some agencies apply as an alternative daily cover or to reclaim a closed landfill • Landfills typically will not accept unstabilized or liquid sludges Brown and Caldwell

27. Liquid Fertilizer • Chemical hydrolysis improves breakdown of organic material • Dewatered solids feed; can be used before or after digestion • Final product is a Class A liquid product at 15-20% solids • Requires steam and alkaline chemical as part of process Brown and Caldwell

28. Primary Biogas End Use Options Brown and Caldwell

29. Heating • Heat is needed for anaerobic digestion process and excess heat can be used for winter building heat • Most utilities use hot water boilers. Steam can be used too. • Most sites do not require gas treatment • Typically cannot use all of the biogas produced; off-site, year-round use required for full biogas utilization Brown and Caldwell

30. Combined Heat and Power (Cogeneration) • Combusts biogas to produce power and recover heat • Typically requires some level of gas treatment • Examples: • Reciprocating engines • Turbines • Microturbines • Fuel cells Brown and Caldwell

31. Biogas Upgrading • Separates methane in biogas from other constituents to produce biomethane • Examples: • Water solvent • Pressure swing adsorption • Membrane • Can be injected into the natural gas utility to offset natural gas consumption • Can be used in CNG vehicles as a vehicle fuel Brown and Caldwell

32. Flare • Required as a backup to combust any waste gas • No energy recovery • Permitting typically requires enclosed waste gas burners (as compared to candlestick flares) Brown and Caldwell

33. Apply Pass/Fail Criteria Brown and Caldwell

34. Apply Pass/Fail Criteria Brown and Caldwell

35. Develop Conceptual Alternatives Brown and Caldwell

36. Conceptual Alternatives Brown and Caldwell

37. Conceptual Alternatives Brown and Caldwell

38. Next Steps • Messaging to Council at March 27 briefing • Action Items Brown and Caldwell