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

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

3. Statistics Subtitle is Arial
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
Use alcohol in moderation. Don’t grill under the influence.

4. Do’s and Don’ts DON’T: 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
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
My father in-law melted the siding on his house because he keeps his grill next to the house.
Clean your grill every time you use it. The clean setting on your grill does not clean it. Use a wire brush while the grill is still warm after cooking

5. Agenda Topic Description Leader Health and Safety Minute Grillin
Giesbrecht
Introduction (5 mins)
Review agenda and meeting objectives
Confirm Selection Criteria
(15 mins)
Confirm updates to pass/fail and
communicate changes to TBL criteria
Matson
Overview of World of Alternatives
(30 min)
Overview of select technologies and end uses 
McKelvey
Apply Pass/Fail
Criteria
(60 min)
Apply pass/fail criteria to world of alternatives
Krugel
Develop Conceptual Alternatives
Develop conceptual alternative packages
from elements making it through pass/fail (to
be analyzed with TBL+)
Giesbrecht/
Next steps (10 mins)
Messaging to Council at March 27 briefing
Action Items
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 ( 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)
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