Download - 1752 Steve Dvorak
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As the USA leader in anaerobicdigestion, DVOs patented, efficientand cost-effective systems provide:
Renewable power generation Quality solid fertilizer Liquid fertilizer for crop application Odor and pathogen control
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DVOisbasedinWisconsin,USA
Foundedin1989bySteveDvorak,P.E.
Packerland digesterin
1985
stilloperating
Ourfirstdigester(patenteddesign)
Gordondale Farms,WIinSeptember2001
DVOistheUSAmarketleader,with84digesters
operatingat64sitesin15U.S.states
19moreareunderconstruction
BACKGROUND
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CONFIDENTIAL PROPERTY OF GHD, INC.
2011 DVO, Inc.
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LARGESTDIGESTER
15,000cowmilkingdairy,
11Mgalloncapacity
4.5MWgeneration
capacity
Commissioningin2011
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Manure/WasteCollection
System
Dairies(flush&scrape),OtherAnimalWastes
MixedMaterials:FoodProcessing,Biofuels,etc.
DigesterVessel
PlugflowDigester
FirstIn,FirstOut
DigesterMixing
BiogasRecirculation
DigesterTemperature
TypicallyMesophilic =
38.3o C
BIOLOGICALSYSTEM
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MIXED PLUGFLOW
Advantages
ForWaste
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MIXED PLUGFLOW
Advantages
ForWaste
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To
more
easily
maintain
an
even
temperature.
By
moderating
temperaturefluctuationsbacteriagrowthisoptimized.
Formoreefficiency:Farlessenergyisrequiredtomaintain
optimal
operating
temperatures
in
cooler
seasons,
than
with
abovegroundtanks
Veryhotdaysalsodonotraisetemperaturestoohigh.
GHDvesselsaremuchstronger
thansteel
tanks,
which
have
been
knowntofreeze,failandeven
rupture(spillingtheircontents)
WhyBelowGround?
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ODORCONTROL
97%Volatile
Fatty
Acid
(VFA)
destructionperEPA AgSTAR study
Wasteiscollectedandcompletely
contained,thentheodorisburnedaway
inthe
biogas
engines.
Thedigestedliquidcanbeland
appliedwithlittleodor.
Facilitiescanbelocatedclosertopopulatedareas(forshorter
wastetransportdistances).
Toobtainafarmpermitsomecommunitiesarenowrequiringa
DVOdigesterforoptimalodorandpathogencontrol.
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PATHOGENDESTRUCTION
Pathogenssuchasecoliandsalmonellaare
reducedinthedigestedwaste oftentothepoint
ofundetectability.
Ananswertoconcernsaboutspreadingraw,unprocessed
farmwastesonfields
ThisabilityispartlyduetoDVOs
guaranteedhydraulic
retention
time.
Unlikecompetitordesigns,everyunitof
wasteisretainedinthevesselforaspecificamount
oftime.Nothingisremovedtoosoon,ortoolate.
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Fecal Streptococcus (col/g WWB) 380,000,000 110,000,000 64,000,000 480,000,000
Fecal Coliform (col/g WWB) 350,000,000 170,000,000 130,000,000 160,000,000
Total Phosphorous (mg/Kg WWB) 950 780 910 750Total Solids (%) 10.9 9.8 9.3 9.3
Volatile Fatty Acids (mg/Kg WWB) 7,520 7,060 6,000 7,140
Fecal Streptococcus (col/g WWB) 8,700,000 6,000,000 1,700,000 34,000,000
Fecal Coliform (col/g WWB) 660,000 370,000 380,000 240,000
Total Phosphorous (mg/Kg WWB) 780 840 860 550
Total Solids (%) 6.4 6.5 6.4 6.1
Volatile Fatty Acids (mg/Kg WWB) 300 282 321 259
12/28/04
11/30/04
11/30/04
DIGESTER EFFLUENT
PARAMETERS 11/3/04
DIGESTER INFLUENT
11/3/04 11/16/04PARAMETERS 12/28/04
11/16/04
EPA AgStar Pathogen
Evaluation:DVO
% DWB = (mg/Kg DWB) / 10,000 mg/Kg = ppm
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55
60%Methane
(CO2 ~45%)
Bydesign,GHDofferssuperiorbiologicaldegradationandthe
highestgasproductionvolumeforanygivenwastestream.For
example: 3.1M3(110ft3)ofbiogas/cow/day
67kW/cow/day(FC,manureonly,NOsubstrates)
Lowestparasiticload(energycostofoperation)
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Guaranteedretention
time
for
the
entire
waste
stream
(for
higherefficiencyandpathogendestruction)
Nostratificationofsolidsinvessel
Constanttemperature
Fulldispersionofbacteriapopulation
Abilitytohandlemultiplewastestreams
Abilityto
handle
awide
range
of
waste
streams,
and
percentsolidsconcentration
REQUIREMENTSFORA
SUCCESSFULDIGESTER
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Farmpractical
operation
Lowmaintenance
CostperkWproduced
kWproducedperunitofWaste
Abilitytoacceptdifferent%solids
Numberofsystemsinoperation(experience&trackrecord)
Systemsparasiticload(%ofkWproduced)
Qualityofseparatedsolids&liquideffluent
Third
party
data
/
performance
verification
DIGESTERSELECTION
CRITERIA
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Thank You !
CHILTON,WI
USA
920
.849
.9797