Digestion of Manure and High Strength Wastes
Mark A. MoserRCM/Biothane LLC Berkeley, CA 510-834-4568
RCM - Who We Are
Digesters are our only business,
>20 years in the digester business
>50 digesters operating
10 digesters finished since Oct. 2005
Staff of 9 in Oakland, California and 2 in Camden, NJ
RCM Philosophy
Provide a solution not a product
Design for Cost Effective Construction
Make them easy to operate
Be Farm Flexible
RCM Digesters for manure and food waste
Covered Lagoon – solubles onlyHeated mixed tank or lagoonPlug FlowMulti-farmMulti-waste
Castelanelli Brothers Dairy Lodi, CA
Covered Lagoon Digester
2,000 cows, Sand Bedding, Flush Collection
180 kW Generator
RCM Digesters
RCM DigestersHeated Mixed Covered Lagoon
Apex Pork Rio, IL8,000 finishersAIAO production
Biogas collection andOdor control since 1998
WPF – Wheatland,Wyoming, 2004 18,000 finish hogs, heated, mixed,
concrete tank digester 160 kW engine,
New Horizons Dairy, 2000 Cow Digester Elmwood, Illinois
New Horizons Dairy, Elmwood, IL Biogas since October 2002
RCM Digesters, Inc rcmdigesters.com510-834-4568
Plug Flow DigesterMeadowbrook Dairy
Phelan, CA1200 cow vacuumed drylot170 kW, separated solids
July 2004
Port of Tillamook Bay
Regional Dairy Digester
4,000 cow capacity at build out
2,000 cows from 8 dairies contributing today
240 kWh continuous
$2,000,000
Operating Requirements:
USNo time-temperature requirements Maybe you can add food, maybe notHRT – 15 – 25 daysTemperature – mesophillic
Europe - CanadaPasteurization or time/temp requirement depending on location and added materials and who is making the rules – Germany v DenmarkHRT – 12 – 20 daysTemperature – depends on HRT
RCM First Accidental Co-digestion
24 years ago cheese whey from Marin French Cheese was added to dairy manure at the Marindale Dairy Digester. Good News! Some whey made some extra gas. The owner then added too much whey and almost killed the digester.
1. Why manure and food waste?
Food waste is typically highly biodegradableSociety wants degradable wastes managed to minimize public health impactDigesters degrade highly biodegradable materials in a controlled fashion and the effluent doesn’t smell, support flies or vermin.Farm digester manure is a complete substrateFood waste may need nutrients from manure to enhance degradation
2. Why manure and food waste?
Farm ViewProfit
Tipping feesExtra Gas and Electricity Production
Waste Generator ViewReduced disposal cost while meeting society goal of controlled degradationFarm has land to manage the waste.
What digests:
Protein - Slaughterhouse waste, fish processing, road killVegetable oilsFats, Oils, Grease (maybe not so well)Carbohydrates – starch, sugar, fruit juice,whey and whey products, grains, some grain processing productsMost cleaning chemicals
What doesn’t digest:
Sticks, leaves Rocks and cement blocksMetal, glass, plastic, rubber glovesSome cleaning or disinfecting chemicals
Bad things to try to digest without testing
Petroleum productsChemicalsPesticides and herbicidesToxic anythingDrugs
Matlink Dairy, Clymer, NY
900 cows + organic wastes, 130 kW
Up to 325,000 ft3/d, solids separated RCM Digesters.com
RCM Complete Mix DigesterRCM Complete Mix Digester
Gypsy Hill Farm - Lancaster, PA
4,000 Pigs and Whey
Biogas and 120 kW since 1983
Original: Energy Cycle 1983
RCM: redesign, rebuild, increase capacity 2000
Patterson Dairy, Auburn, NY, 2005, 1200 cows and whey, 200 kW, up to 500,000 ft3 of gas/day, big flare, solids
The learning:
Ditto on the big flare, gas keeps on comingOne mans whey permeate is another mans processed whey concentrate
The learning:
Steady feeding keeps the engine runningDitto on the evil nature of utilities – (Sorry I can’t help myself)
Potential Pitfalls
Zoning - Food waste is sometimes ruled an industrial waste. A farm might have to be rezoned for accepting industrial waste.
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:
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!
Advice:
Permit a digester for food wasteBe honest with the neighbors
THERE IS HOPEEnlightened states like New York and Pennsylvania have been reasonable.Enlightenment awaits provinces like Ontario and states like California
The Rules of Digesters
DoFeed dailyFeed a constant dietKeep the digester warm
Don’tFeed too much or too littleOver or under heat
The Rules Food Wastes
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.Quality or quantity? Never on Sunday unless its Sunday.
The Rules of Mixed Wastes
A digester that receives food waste should be a digester designed to receive food waste.
The Consequences of Violating the Rules:
Death to the digester
Dishonor to the operator
Loss of waste source.