1752 Steve Dvorak

7/31/2019 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

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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 !

[email protected]

CHILTON,WI

USA

920

.849

.9797

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1752 Steve Dvorak