Producing Biogas from Manure and Foodwaste: Three Case Studies

Co-digestion of Manure and
High Strength Wastes
Guillermo Luzardo
RCM
Berkeley, CA
510-834-4568
RCM - Who We Are
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Digesters are our only business,
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>20 years in the digester business
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>50 digesters operating
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Staff of >10 in Oakland, California
RCM Philosophy
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Cost Effective Construction
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Easy to operate – 1.5 cts per kWh
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Flexibility
RCM Digesters for mixed manure
and food waste
Covered Lagoon – solubles only
„ Heated mixed tank or lagoon
„ Plug Flow
„ Multi-farm
„ Multi-waste
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Why manure and food waste?
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Food waste is typically highly biodegradable
Society wants degradable wastes managed to
minimize public health impact
Digesters degrade highly biodegradable
materials in a controlled fashion and the effluent
doesn’t smell or support flies
Food waste may need nutrients from manure to
enhance degradation
Why manure and food waste?
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Farm View
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Profit
„ Tipping fees
„ Extra Gas and Electricity Production
Waste Generator View
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Reduced disposal cost while meeting society
goal of controlled degradation
Farm has land to manage the waste.
What digests:
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Protein - Slaughterhouse waste, fish
processing, road kill
Vegetable oils
Fats, Oils, Grease (maybe not so well)
Carbohydrates – starch, sugar, fruit
juice,whey and whey products, grains,
some grain processing products
Most cleaning chemicals
What doesn’t digest:
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Sticks, leaves
Rocks and cement blocks
Metal, glass, plastic, rubber gloves
Some cleaning or disinfecting chemicals
Bad things to try to digest without testing
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Petroleum products
Chemicals
Pesticides and herbicides
Toxic anything
Drugs
Langerwerf Dairy, Durham, CA
1983, 350 cows, 70 kW,
45 kW without FOG
70 kW plus flare with FOG
Kluthe Farm– Dodge, NE, 2006
8,000 finish hogs, 70 kW,
Patterson Dairy, Auburn, NY, 2005, 1200
cows and whey, 200 kW, big flare, solids
Lastly – 28,000 steers and thin
stillage. Nebrasca NBC
Castelanelli Dairy – 180 kW
Gas Handling
Castelanelli, Lodi, Ca
400 hp Biogas Boiler and Gas Skid, Chile
Potential Pitfalls
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Zoning - Food waste is sometimes ruled as
industrial waste. A farm might have to be
rezoned for accepting industrial waste.
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Permitting – Food waste is often regulated as a
solid waste. A farm may have to have a solid
waste permit and compliance schedule to
operate.
Nutrients - The other pitfall:
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When bringing waste to a farm, are
nutrients coming in the waste?
Can imported nutrients be used on the
farm?
Does the nutrient management plan or
permit need to be altered? YES!
Some lessons
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Check what’s in the truck
Big flares can be your friend
Steady is good
Advice:
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Permit a digester for food waste
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Enlightened states like New York and
Pennsylvania have been reasonable.
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Enlightenment awaits provinces like
Ontario and states like California
The Rules of Digesters
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Do
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Feed daily
Feed a constant diet
Keep the digester warm
Don’t
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Feed too much or too little
Over or under heat
The Rules Food Wastes
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Rule 1. There are no rules - Not all food
waste is equal.
Waste means waste to the producer.
Truckload means what’s in the truck.
What RCM does:
1. Budget Prices
2. Feasibility Study
3. Design and equipment supply
4. Turnkey construction
Questions
Agro Super, Chile, 2002
120,000 finish hogs
heated, mixed, covered digester, boiler