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7/31/2019 Biofuels From Coconuts - Ver3
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BIOFUELSFROMCOCONUTS
KrishnaRaghavan
August2010
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TABLE OF CONTENTS
1 POTENTIAL FOR BIOFUELS FROM COCONUTS 1
1.1 QUANTITYANDENERGYCONTENTOFPARTSOFTHECOCONUTPALM 1
1.2 POTENTIALFORPOWERGENERATIONFROMUNUSEDCOCONUTBIOMASS 2
1.3 DECENTRALISEDPOWERGENERATIONFROMCOCONUTRESIDUES 5
1.4 DIESELSAVINGSANDEMISSIONSREDUCTIONS 6
2 POST HARVEST TREATMENT AND PROCESSING 8
2.1 NUTSTORAGE 8
2.2 DEHUSKING 9
2.3 NUTTRANSPORTATION 11
2.4 CRACKING 11
2.5 COPRAMANUFACTURE 11
3 COCONUT OIL - COMPOSITION AND PROPERTIES 13
3.1 COMPOSITION 13
3.2 FUELRELATEDPROPERTIES 13
4 OIL PRESSING & REFINING 15
4.1 DRYPROCESSANDOILREFINING 15
4.2 WETPROCESS 17
4.2.1 RamPress 17
4.2.2 DME DirectMicroExpelling 18
5 UTILIZATIONOFLIQUIDBIOFUELS 20
5.1 COCONUTOILFORDIESELENGINES 20
5.1.1 InternalCombustionEngines 20
5.1.2 FuelInjection
20
5.1.3 QualityStandardsforCoconutoil 26
5.2 BIODIESEL 27
5.3 CASESTUDIESINPACIFICANDLESSONSLEARNED 30
5.3.1 Islandfuel,Vanuatu 30
5.3.2 Cocogen,Samoa 34
5.3.3 CoconutoilforpowergenerationinFiji 40
6 UTILIZATIONOFSOLIDBIOFUELS SHELLS&HUSK 46
6.1 CHARACTERISTICS 46
6.2 BASICPRINCIPLESOFCOMBUSTION 46
6.3 CURRENTUSES 48
6.4 WASTEHEATUNIT(WHU) 48
6.4.1 WHUforCopraProduction 51
6.4.2 ProductRecovery 54
7 REFERENCES 58
8 ANNEXES 61
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8.1 THECOCONUTPALM 61
8.1.1 PartsandUses 61
8.1.2 OriginandDistribution 62
8.1.3 WorldProduction 63
8.1.4 Plantingmaterial,SelectionandBreeding 64
8.1.5 Plantingpractices
67
8.1.6 Greenmanuring,OrganicManuring&ChemicalFertilizerapplication 71
8.2 DRYINGMETHODSOFCOPRA&STORAGE 80
8.2.1 BasicPrinciplesofCoconutDrying 80
8.2.2 TypesofDryers 82
8.2.3 CopraStorage 102
LISTOFTABLES
Table1 CompositionofonematureCoconutbyWeight............................................................ 1
Table2 QuantityandEnergyContentofpartsoftheCoconutPalm.......................................... 2
Table3 PotentialforPowergenerationfromCoconutResidues............................................... 4
Table4PowerGenerationPotentialfromUnusedResidues(1,000tonscopraequiv./year)......5
Table5 DieselsavingsandEmissionsReductions....................................................................... 6
Table6 DieselPriceandSavings................................................................................................. 6
Table7 EffectsofStorageTimeonDehuskedNuts.................................................................... 8
Table8 Thechemicalcompositionofcoconutoil..................................................................... 13
Table9 Fuelrelatedpropertiesofvegetableoilsandpetroleumdiesel...................................14
Table10 DraftQualityStandardsforCoconutOilasaFuelinengines....................................27
Table11 PhysicoChemicalpropertiesofCoconutMethylEster(CME)...................................28
Table12 ComparisonofMoistureandOilContentfromWHUwithothermethods...............56
Table13 Waterholdingcapacityofairinatropicalcountry.................................................... 80
Table14 MaterialsrequiredforconstructionofaSolarDryer................................................. 87Table15 PropertiesofLLD andLD PolyEthyleneplasticsheets............................................ 88
Table16 AssumptionsforSolarDrying..................................................................................... 89
Table17 QualityStandardforCoprainthePhilippines.......................................................... 104
Table18 GradesofCopraUsedinthePhilippines.................................................................. 105
Table19 ContractTermsfortradingCoprainIndia................................................................ 105
Table20 ClassificationofCopraforexportinPapuaNewGuinea......................................... 106
LISTOFFIGURES
Figure1 CompositionsofMatureandDryCoconutbyweight................................................... 1
Figure2 Ratioofweightsofpartsofthecoconutpalm.............................................................. 2
Figure3 EnergyfromUnusedCoconutBiomass......................................................................... 3
Figure4 PowerGenerationpotentialofCoconutResidues........................................................ 3
Figure5 Schematicofdryprocessforcoconutoilextraction................................................... 15
Figure6 DirectIgnitionengine.................................................................................................. 21
Figure7 IndirectIgnitionengine............................................................................................... 21
Figure8 Effectofchambertemperatureoncombustionofcoconutoil..................................23
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Figure9 A2tanksystemforusingCoconutOilinaDirectinjectionengine...........................25
Figure10 Heatcontentsintheconversionofshellstocharcoal.............................................. 48
Figure11 SchematicoftheWasteHeatUnit............................................................................ 51
Figure12 TypicalTunnelDrierandLayoutofWHUbasedcopradryingsystem......................54
Figure13 DryingCurve.............................................................................................................. 81
Figure14 TheSeeSawDrier..................................................................................................... 84Figure15 EnergyFlowsinaSolarDryer.................................................................................... 85
Figure16 SolarDryerdesignedbythePhilippineGermanCoconutProject............................86
Figure17 DryingCurvesforSunDryingandSolarDrier........................................................... 88
Figure18 SchematicofTapahandryer...................................................................................... 92
Figure19 SchematicofUPLBdryer........................................................................................... 94
Figure20 VISCACopraDrier...................................................................................................... 97
Figure21 SchematicofModifiedKukumdryer......................................................................... 98
Figure22 SchematicofCocopugonDryer............................................................................... 101
LISTOFPHOTOS
Photo1 ManualCoconutDehuskingTool................................................................................... 9
Photo2 CoCoMaNdehushingmachine................................................................................ 10
Photo3 BreakingcoconutsformakingCopra........................................................................... 11
Photo4 EdibleBallcoprawholeandcutintohalves............................................................. 12
Photo5 CoconutoilextractionusingtheRamPress................................................................ 17
Photo6 Effectsofimpropercombustionofcoconutoilinengine........................................... 22
Photo7 Heatexchangerusedforconversionofcarstorunoncoconut oil............................22
Photo8 Auxiliaryequipmentusedwitha2tanksystem......................................................... 25
Photo9 IslandFuelFillingStation............................................................................................. 30
Photo10 RangeRoverandToyotaRunningonVanuatuCoconutOil......................................32
Photo11 CumminsDirectInjection400kWDieselEnginetestedwith10%coconutoil.........35Photo12 FilteringofCoconutOilwithaSheetBeforemixinginthedaytank........................39
Photo13 CoconutOilproductionequipmentatWelangi......................................................... 41
Photo14 45kVAdieselgensetatWelagi.................................................................................. 42
Photo15 The90kVAdieselgensetatVanuabalavu.................................................................. 43
Photo16 Traditionalmethodofburningcoconutshellsinapit.............................................. 49
Photo17 PrototypeWasteHeatRecoveryUnittestedbyNRI,Culham,UK............................50
Photo18 TraditionalCopraDrying............................................................................................ 52
Photo19 AWasteHeatUnitinSriLanka.................................................................................. 55
Photo20 CoprafromTraditionalsmokedriersandfromtheWHUprocess............................55
Photo21 CharcoalproducedbytheWasteHeatUnit.............................................................. 57
Photo22 Sundryingcopra........................................................................................................ 83
Photo23 DirectSmokeCopraDryer......................................................................................... 92
Photo24 SemiDirectSmokeCopraDryer................................................................................ 95
Photo25 ModifiedKukumhotairdryer................................................................................... 99
Photo26 CocopugonHotAirBrickCopraDryer..................................................................... 100
Photo27 CopraMoistureMeter............................................................................................. 106
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1 POTENTIAL FOR BIOFUELS FROM COCONUTS
1.1 QuantityandEnergycontentofpartsoftheCoconutPalm
Whenamaturecoconutisharvestedafter11or12months,itisfilledwithcocowateranditskernel,shellandhuskareinawetcondition. Generally,thecoconutisdehuskedandtheshell
splitopensothatthekernelcanbetakenoutanddriedintocopra. Insomecountries,
especiallyinthePacific,thewholenutissplitopenwithoutdehusking. Compositionsofboth
thematurecoconutwhenharvestedandafterithasbeendriedareshowninFigure1.
Figure 1 Compositions of Mature and Dry Coconut by weight
Note: HusksarecomposedofCoirandCoirdust.
Theweightofacoconutdependsonthecultivarorhybrid. Thebreakupintoitscomponents
ofanaveragecoconutthatweighs1.2kgsisgiveninTable1.
Table 1 Composition of one mature Coconut by Weight
Part Weight [ kgs]
Whole Coconut 1.2
1 Husks (Coir + Coir dust) 0.39
2 Shells 0.17
3 Coco water 0.24
4 Green Copra 0.37
4a Dry Copra 0.2
4b Moisture 0.17
4a-1 Copra Meal 0.08
4a-2 Copra Oil 0.12
Note: Averagevaluesfor1,000nuts
Source: Cloin,2005
Copra,thedriedkernelthatisusedtoextractcoconutoil,isthemostimportantproductfrom
thecoconut,andcoconutproductionisveryoftengivenintonnesofcopraequivalent. The
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ratioofweightsofthedifferentpartsofacoconutpalmtothedriedkernelisshowninFigure2
andTable2. Thefronds(leaves)havethemaximumweightatover4timestheweightofthe
kernel,androughlyonenewleafisproducedandanoldonedropsonceeverymonth. The
trunk(stem)isnextat1.45timesthekernel,butthestemcanonlybeharvestedonceatthe
endofitslifetime. Theweightofthehusk(coir+coirdust)is1.3timesandoftheshellis0.9
timestheweightofthekernel,allthreebeingproducedtogetherinonenut. Finally,the
kernelitselfconsistsoftwoparts: CoconutOilisroughly60%;
CoconutMeal(orOilCake)thatremainsaftertheoilisextractedweighsabout40%.
Table 2 Quantity and Energy Content of parts of the Coconut Palm
Dry Kernel CN-Oil CN Meal Shell Coir Coir dust Fronds Trunk Combined
Ratio to "Dry" Kernel (%)
(@ 4% moisture content) 100% 61% 39% 90% 39% 91% 426% 145% 991%
Energy Content (GJ /t) 29.1 37.7 15.7 18.2 16.7 16.7 16.7 16.7 16.2
Source:Hagen,1995
Figure 2 Ratio of weights of parts of the coconut palm
Source:DatafromHagen,1995.
1.2 PotentialforPowerGenerationfromUnusedCoconutBiomass
Globalannualproductionofcoconutsin2005wasaround59.6billionnutequivalentor11.9
milliontonnescopraequivalentharvestedfrom1.2billionpalmson12.2millionha(APCC,
2006). Thetotalbiomassproduction(excludingthecocowaterbutincludingthekernel)is
106,100kilotonnes,ofwhich60.5%amountingto64,200kilotonnesisunprocessed. To
estimatethepowerthatcanbegeneratedfromunusedcoconut,thefollowingprocedurehas
beenfollowed(Hagen,1995):
1. Estimatethequantityofbiomassproducedbythecomponents(CNoil,CNmeal,shell,
huskconsistingofcoiranddust,fronds i.e.leaves,andtrunk).
2. Estimatereportedindustrialproductionofcomponents.
3. Theunusedcoconutbiomassfromthepalmsprocessedistakenasindustrialwaste.
4. Estimatethequantitiesusedbysmallholders.
5. TheremainderisAvailableUnprocessedBiomass.
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6. MultiplyunprocessedportionofeachcomponentwithitsEnergyContenttogivethe
GlobalUnusedBiomassEnergy.
7. Estimatethebiomassenergyavailableforelectricitygenerationas70%oftheunprocessed
biomass.
8. CalculatetheElectricityGenerationPotentialinGigaWattHours(GWh)basedontheNetEfficiencyofthetechnologyusedforpowergeneration(Steamengines:10%; Gasifier+ IC
engine:18%)9. EstimatethetotalcapacityofpowergenerationinMegaWatts(MW)bytakingaLoad
Factorof50%.
Figure 3 Energy from Unused Coconut Biomass
Figure 4 Power Generation potential of Coconut Residues1
1AsperSystemeInternational(SI)usage,tonnereferstothemetrictonof1,000kg;PJ=petajoule=1015
Joules.TJ=terajoule=1012
J;GJ=gigajoule=109
Joules;MJ=megajoule=106
Joules.
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TheresultsaregiveninTable3:
TheGlobalUnusedBiomassEnergyis1,125PetaJoules (PJ)ofwhich70%amountingto
788PJisassumedavailableforpowergeneration.
Ifthisbiomassisburnedinasteamengine,itcangenerate21,900GWhofelectricity. Ifitisburnedinagasifieritcangenerate39,400GWh.
Ata50%LoadFactor(12hoursperday),thetotalpowergenerationcapacityis5,000MW
usingefficientsteamengines. However,bygasifyingthebiomassandusingInternalCombustionengines,thetotalcapacityis9,000MW.
Table 3 Potential for Power generation from Coconut Residues
PORTION > Kernel CNOil
CN
Meal Shell Coir
Coir
dust Fronds Trunk Combined
AirDryMatter/FreshWeight
assumed* % 95% 62% 62%
Ratioto"Dry"Kernel(@4%
MC)* % 100% 61% 39% 90% 39% 91% 426% 145%
Total Global Coconut
Production kt 11,913 7,267 4,646 10,722 4,646 10,841 50,749 17,274 106,144
Industrial "Production" % of
Total* % 43% 43% 43% 55% 55% 55% 55% 55%
Industrial"Production" kt 5,145 3,138 2,007 5,897 2,555 5,962 27,912 9,501 56,972
Commercial Consumption
Copra kt 4,776 2,917 1,761 843 291 5 11,410 356 17,377
DesiccatedCN+CNCream kt 323
%Commercial/Total* % 40.1% 40.1% 37.9% 10.5% 8.4% 0.1% 30.0% 2.7% 21.8%
%Commercial/lIndustrial % 99.1% 93.0% 87.8% 19.1% 15.2% 0.1% 54.6% 5.0% 40.0%
Industrial"Waste" kt 46 221 245 4,771 2,167 5,956 12,672 9,026 35,058
%Industrial"Waste"* % 0.9% 7.0% 12.2% 80.9% 84.8% 99.9% 45.4% 95.0% 61.5%
Smallholder eating/cooking
etc. kt 3,574 2,180 1,394 536 232 542 13,854 864 19,602
%Smallholderuse* % 30.0% 30.0% 30.0% 5.0% 5.0% 5.0% 27.3% 5.0% 18.5%
Available Unprocessed
Biomass kt 3,194 1,948 1,246 9,060 4,023 10,288 21,670 15,944 64,179
Global Portion
Unprocessed % 26.8% 26.8% 26.8% 84.5% 86.6% 94.9% 42.7% 92.3% 60.5%
EnergyContent* GJ/t 29.1 37.7 15.7 18.2 16.7 16.7 16.7 16.7 16.2
Global Unused Biomass
Energy PJ 93 73 20 165 67 172 362 266 1,125
Biomass available for
Electricity@70% PJ 65 51 14 115 47 120 253 186 788
NEElectricity Generation
Potential
GWh 10% 1,809 1,429 381 3,209 1,308 3,343 7,042 5,181 21,893GWh 18% 3,256 2,573 685 5,776 2,354 6,018 12,676 9,327 39,408
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PowerGenerationPotential
@50%Loadfactor
MW 10% 413 326 87 733 299 763 1,608 1,183 4,998MW 18% 743 587 156 1,319 537 1,374 2,894 2,129 8,997
Table 4 Power Generation Potential from Unused Residues (1,000 tons copra equiv./year)
Portion>> Kernel CNOil
CN
Meal Shell Coir
Coir
dust
Fronds
(Leaves) Trunk Combined
EquivalentMassRate
@50%Loadfactor kg/hr 228 139 89 205 89 208 973 331 2,988
EquivalentHeatrate kW 1,846 1,458 388 1,036 412 960 4,504 1,535 13,445
MinimumEnergyAvailable % 15.1% 15.1% 15.1% 79.4% 0.0% 99.0% 42.7% 50.0% 37.7%
PowerwithGasifierGenset kW 18% 40 11 148 172 347 138 855Source:AuthorscalculationswithAssumptions(*)fromHagen,1995;
Note: (a)NE=NetEfficiency; (b)AsperSystemeInternational(SI)usage,tonnereferstothemetricton
of 1,000 kg; PJ = petajoule = 1015 Joules. TJ =terajoule = 1012 J; GJ = gigajoule = 109 Joules; MJ =megajoule=106Joules.
1.3 DecentralisedPowerGenerationfromCoconutResidues
Generally,thefarmerdriesthekernelandsellsthecoprathroughmiddlementothelarge
coconutoilmillsthatarelocatedinurbanareasandprocesscopraintococonutoilandmeal
(oilcake). Forexample,around100coconutprocessingplantsinthePhilippinesaregenerally
verylarge(500,000to5,000,000nuts/dayor30,000to300,000tonscopra/year). However,
over90%ofcoconutsaregrownbysmallholdersmanyofwhomdonothavepowersupply.
Coconutscanbeprocessedlocallyinsmallerprocessingplants,andtheenergyoftheunused
biomasscanbeusedtogeneratepowerforthepopulationresidingnearby.
Asmallprocessingplantthatcoverts1000tonnescopraequivalentperyearisanalysedin
Table4. Onanaverage,5millionnutsarerequiredtoproduce1000tonnescopra(5nutsper
kgcopra). Thiscancomefrom1,000smallholderseachproducinganaverageof1tonnecopra
peryear,orfrom2,000smallholderseachproducinganaverageof0.5tonnecopraperyear.
If70%oftheunusedbiomassisusedforpowergenerationinaBiomassGasifier+ICengine
systemoperatingatanetefficiencyof18%,1,000kWofelectricitycanbegeneratedfor10
hourseveryday(50%loadfactor). If25%oftheworldscoconutproductionisprocessedin
thisway,thereisaglobalpotentialfornearly3,000suchdecentralizedpowerplantsof1MW
capacity.
Evensmallermicroscaleprocessingunitsmaybethemostappropriatesolutioninmany
locationsespeciallyonsmalltropicalislandsmostofwhichgrowcoconuts. Thegasifier+IC
enginesystemalsoproduceswasteheatthatcanbeusedfordryingthecopra. Forexample,in
combinationwithanoilmillprocessing10tonnesofcopra/year,a10kWgasifier+gasengine
powerplantcanbeinstalled. Thiswillutilizethecoconutproductionofabout20smallholders
andcatertotheirelectricityneedsaswell. Ifonly1%oftheglobalcoconutproductionis
processedinsuchmicrooilmills,thereisapotentialfor12,000powerplantsof10kWcapacity
thatcanprovidepowerto240,000smallholders.
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Smallscalepowergenerationintheruralareascanstimulatedevelopmentofsmalland
mediumscaleindustriesthataddvaluetolocallyavailablerawmaterials. Byproviding
additionalemploymentopportunitiesandincomegenerationitcanalleviatepoverty.
1.4 Dieselsavings
and
Emissions
Reductions
DieselSavings
Ifelectricityfromdieselpowerplantsisdisplacedbytheelectricityproducedfromcoconut
residues,then11.8billionlitresofdiesel(74millionbarrels)canbesavedinayear. Thiswill
leadtoareductioningreenhousegasemissionsof32milliontonnesofCO2(Table2).
Table 5 Diesel savings
ElectricityproducedfromResidues 39,408 GWh/year
Dieselsavings 11.8 billionlitres/year
= 74 millionbarrels/year
Assumptions:
Dieselusageforelecticitygeneration= 0.30 litres/kWh
Thevalueof11.8billionlitresofdieselatvariouscrudeoilpricesisgiveninTable3. Thevalue
ofdieselis5.2and10.4billionUS$atacrudeoilpriceof50and100US$/barrelrespectively.
Table 6 Diesel Price and Savings
CrudeOil Diesel Dieselsavings
US$/bbl US$/litre billionUS$
50 0.44 5.20
100 0.88 10.41150 1.32 15.61
200 1.76 20.82
Assumption:DieselPriceis40%morethanCrudeOilprice
(Refining&Profit=32%;Distribution&Marketing=8%)
Source:EIA,USA
EmissionsReductions
Atareductionof2.7kgcarbondioxide(CO2)foreverylitreofdieselsaved,thetotalemissions
reductionsfromthedieselsavingsalonewillbe32milliontonnesCO2/year.
However, this is not the total CO2 emissions reductions resulting from electricity generation
usingbiofuelsfromcoconutinsteadofdiesel. ThereareCO2emissionsduringtheproduction
and processing of coconuts, and usage of coconut biofuels in engines that have to be taken
intoaccount. Theseemissionsareduetofossilfuelsusedin:
Production of coconuts from fossil fuels used to produce fertilisers used, in farm
mechanisation,etc.;
Processing coconuts from fossil fuels used for transportation of coconuts and its
products,andforproducingheat&electricityatoilmill,etc.;
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Engine modifications from fossil fuels used in producing biomass gasifiers,
componentsusedtomodifyenginestorunoncoconutoil,etc.
Togetafairpictureofcarbonsavingsbyreplacingdieselbycoconuts,afulllifecycleanalysisof
the coconut fuel chain has to be carried out in which all these CO2 emissions have been
accountedfor.
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2 POST HARVEST TREATMENT AND PROCESSING
2.1 NutStorage
Nutsaregenerallydehuskedsoonafterharvesting,ifpossibleonthesameday. Storageofthe
nutsisnotreallyrequiredbeforedehusking,exceptforverygreennutswhichareeasierto
dehuskaftersomestorage.Duringperiodsofpeakharvests,notallnutsharvesteddailycanbe
dehuskedthesameday,andstoragewillbenecessary.Tomaintainacertainstockmayalsobe
necessarytokeepthedehuskingteamconstantlysuppliedwithcoconuts.
Storageofnutsshouldbedoneinasdryconditionsaspossible,preferablyunderaroofand
closetothedehuskingsite.Toreducetransportationcosts,nutsaresometimesstoredunder
thetreesforlocaldehusking,butthisincreasestheriskofnuttheftandrodentattack.Local
experienceisthebestindicatorofthepossibilitiesforstorageduringthewetandthedry
seasons.
Table7givestheeffectsofstoragetimeonthegermination,moisturecontentandformation
ofballcopra.
Table 7 Effects of Storage Time on Dehusked Nuts
StorageTime(months) Germination MoistureContent
1 1% 80%
2 9% 66%
3 27% 55%
BallCopraFormation
6 10%
7 33%8 70%
9 100%
Source:(Ohler,1999)
Theadvantagesofstoringorseasoningharvestednutsbeforetheyareprocessedfurtherare:
Moisturecontentofthemeatdecreases;
Germinationpercentageincreases;
Moreuniformcopraquality;
Dehuskingbecomeseasierespeciallywiththegreenercoconuts.Trialsindicatedthat
whole12montholdnutsdriedsufficientlywithintwomonthstofacilitatehuskingand
copraextraction.
Shellingbecomeseasierandcleaner;
Greatermeatresistancetobacterialslimingduringsundrying;
Underverydryconditionsnutsmaydryoutduringstoragewithoutgerminating.Thismayfacilitatedehuskingandscoopingoutofthecoprafromtheshell.
(Ohler,1999)
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2.2 Dehusking
Thesimplestmethodofremovingthekernelfromthenutisbysplittingthenutintotwo
halvesorthreepartswiththeuseofaaxewithoutdehusking,andthisisdoneinseveral
islandsinthePacific. Thekernelcanthenbescoopedwithaknifeouttobesundriedortaken
tothekiln,butmoreoftenitistransporteddirectlytoaprocessingfactorywithhotairdryers
forcopramanufacture.Thehuskwiththeshellattachedtoitisusedasfuelforthedryer
typicallyabout50%isrequiredfordrying.
Thismethodhasseveraldrawbacks:
Thewetendospermstickstotheshellandcannotberemovedinhalvesorlargepieces.Thekernelisscoopedoutwithaflatmetalimplementresultinginfingercutkernels.
Theincreasedsurfaceofthecutendospermexposedtotheairincreasesdeterioration.
Thereisalsoanincreasedriskofcontamination withdirtintheplantation.
Whentheendospermistransportedinbagsandpoundedtoreduceitsvolume,
deteriorationwillbemuchincreased,particularlyifthesebagshavebeenusedbeforefor
thesamepurpose.
Bothhusksandshellsnotusedasfuelremaininthefield.Theshellwilltakealongtimetodecomposeandmaybecomeanuisance.
In most of the coconut growing countries, the first step in the postharvest treatment of
coconutsisdehusking,oftendoneintheneighbourhoodofthecoprakiln.
Thisishardworkandistraditionallydonemanuallybylabourexperiencedindehusking.
Dehuskingreducestheweightofnutsbyabout40%andthevolumebyabout60%.
Thecostofnuttransportationtothekilncanbereducedbydehuskingthenutsunder
thetrees,sothatonlytheunopenednutsinshellshavetobetransportedtothekiln.
Thehusksremaininthefieldforuseasanorganicmulchandfertilizersinceitisrichin
plantnutrientsanddecomposeseasily. Whennutsaredehuskedinthefield,they
mustbeshaded,sothattheydonotburstwhenheatedbysunshine. However,ifthehusksarealsotobeusedasfuelfordryingthendehuskingmightas
wellbedonenearthekilnsorhotairdryers.
Photo 1 Manual Coconut Dehusking Tool
Source:FAO
Themostfrequentlyuseddehuskingmethodisbytheuseofapointedmetalspike,securedin
thegroundinaslightlyslantingposition,withthepointupwards(Photo1).Thenutsare
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broughtdownwithforceonthespike,followedbytwistingthenutsidewaysagainstthespike,
looseningthehusk.Thismovementisrepeatedonceortwiceforthetotalremovalofthehusk.
Careistakenthatthepointofthespikeentersthehuskatthestalkendsoastoavoidthe
damagingtheshell.
Dehuskingishardwork;itislowpayingandnotverypopular,soitisoftendifficulttofind
labourforthisoperationeventhoughitcanprovidejobsfortheunemployed. Thenumberofnutsonemancandehuskperdaydependsverymuchonthetypeofthenuts,thethicknessof
thehusk,andtheskillandenergyoftheoperator. Anaverageexperiencedworkeriscapable
ofdehusking1200to1500nutsperday. AnaverageworkerinMalaysiagenerallymanagesto
process1000MalayanTallnuts,1200MAWAhybridsor1500MalayanDwarfnutsperworking
day.Inmostcountries,dehuskingandsplittingareperformedbydifferentlabour.
Variousmechanizedsystemshavebeendevelopedduringthepastdecades,butnosystem
reallymadeanimpactanddehuskingisstilldonemanuallyinmostplaces. Majorproblemsfor
mechanicaldehuskingincludedifferentsizesofnutsandshells,andthedifferentstagesof
maturityoftheharvestednuts(thiscanbeovercomebystoringthenutsforafewweeks).
DevelopmentofdehuskingmachineshasbeencarriedoutinMalaysia,theUK,Indiaand
TrinidadandTobagobutusageinlargenumbershasbeenslow. Reasonsforlowacceptability
ofthemachinesincludelowprocessingcapacityandhighlabourandotheroperatingcosts.
(Ohler,1999)
TheCoCoMaNdehushingmachineavailablefromMethodMachineWorksSdnBhdin
MalaysiaisshowninFig .(http://www.coconutmachine.com/). FOBcostin6,5007.500
USD.
Photo 2 CoCoMaN dehushing machine
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Source: http://www.coconutmachine.com/
2.3 NutTransportation
Thesystemofnuttransportationdependsonthevolumeofnutstobehandledandthe
distanceoverwhichthisvolumehastobetransported. Insmallcoconutfarms,thefarmer
transportsthenutstohishousehimself. Asthesizeofthefarmsandthenumberofnuts
increases,othermodesoftransportationareusedincludinglargebasketsonbicycles,horses
ordonkeysandanimaldrawncarts. Inlargeholdingsnutsaretransportedbytractordrawn
cartstothedryingkilnwheretheyaresplitanddrainedbeforebeingplacedinthekiln. In
somelargeplantations,nutsarebrokenimmediatelyandplacedinbagsholdingabout40
brokennutseach. However,transportationhastobereadilyavailableandwaitinghoursat
thekilnmustbelow,otherwiseopenednutswillstartmouldingwithinoneday. Trucksare
normallyusedfortransportingnutstoacentralfactoryoutsidetheplantation.
2.4 Cracking
Thesecondsolidbiofuelfromthecoconutistheshell. Theshellisseparatedfromthekernelby:
cracking ifcopraorvirgincoconutoilistobeproduced;or
shellingifdessicatedcoconutistobeproduced.
Dehuskedcoconutsarecrackedorsplitintotwohalvesalongtheequatorwithasteelrodor
heavyknife.Thisisdoneformakingcopraortofacilitategratingfordomesticusesorfor
productionofvirgincoconutoil.Crackingiscarriedoutmanually,andthereisnoneedfor
mechanization.
Photo 3 Breaking coconuts for making Copra
Source: Breagetal,1994
2.5 CopraManufacture
Coconut oil is mostly produced made in large mills fromthedried kernel calledcopra. When
making mill copra, the objective is to dry the kernel of the freshly opened nut from the 50%
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moisture level down to 6% as fast as is practically possible. The high moisture content and
presenceofproteinandsugarmakesthefreshkernelanidealmediumforthedevelopmentof
bacteria and fungi. It is therefore liable to deterioration and very susceptible to attack by
microorganisms, withthe developmentof freefattyacidsandranciditythatdegradethe fuel
qualityoftheoil,andalsotheformationofaflatoxinwhichisahighlypoisonouschemical.
Since copra is considered as a low value product, it is not economically viable to use
sophisticated dryers, or even the use of blowers for a more constant airflow. Therefore, formakingcopra,naturaldraftdryersareused. Commonmethodsofdryingcanbeclassifiedas:
1) UsingHeatfromtheSun
a) Sundryingb) Solardrying
2) UsingHeatfromburningBiomass
a) KilndryingusingSmoke DirectorSemidirectdrying
b) IndirectdryingusingHotair
DryingmethodsforproductionofcopraaredescribedinAnnex2.
Inadditiontothemillcoprawhichismilledforoilandcake,therearetwoothertypesofcopra
producedinmuchsmallerbutsignificantquantitiesforediblepurposes:
BallCopra drying iscarriedoutmainlyby storageontheplatformundercomplete
shadeforperiodsof6 8months.Duringtherainyseasonartificialdryingisdone.
Edible Copra the fuel used for drying is coconut shell charcoal, which produces an
even cleanerdirect heat. Sometimes a small amountofsulphur isburnt toobtain an
attractivewhitecolour.
Photo 4 Edible Ball copra whole and cut into halves
Source:Rethinametal,2002
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3 COCONUT OIL - COMPOSITION AND PROPERTIES
3.1 Composition
Coconutoilisamixtureofchemicalcompoundscalledglyceridescontainingfattyacidsand
glycerol.ThedifferentfattyacidspresentincoconutoilrangefromC6 C18carbonatom
chains. Theoiliscontainedinthekernelormeatofthenut. CoconutnutoilandPalmkernel
oilsarecalledlauricoilssincethemaincomponent(over50%)islauricacid.
Table 8 The chemical composition of coconut oil
Component Fraction%(1) ChemicalFormula Systematicnamea Acronymb
Lauricacid 51.0 CH3(CH2)10COOH Dodecanoicacid 12:0
Myristicacid 18.5 CH3(CH2)12COOH Tetradecanoicacid 14:0
Caprilicacid 9.5 CH3(CH2)6COOH Octanoicacid 8:0
Palmiticacid 7.5 CH3(CH2)14COOH Hexadecanoicacid 16:0
Oleicacid 5.0 CH3(CH2)7CH=
CH3(CH2)7COOH
9ZOctadecenoicacid 18:1
Capricacid 4.5 CH3(CH2)8COOH Decanoicacid 10:0
Stearicacid 3.0 CH3(CH2)16COOH Octadecanoicacid 18:0
Linoleicacid 1.0 CH3(CH2)4CH=
CHCH2CH=
CH(CH2)7COOH
9Z,12Z Octadecadienoic
acid
18:2
Source: Knotheetal,1997except(1) Hilditch,1956.
Note: a)Zdenotescisconfiguration; b)Thenumbersdenotethenumberofcarbonatomsanddouble
bondsinonemolecule.Forexample,inoleicacid,18:1indicatesthateachmoleculecontainseighteen
carbonatomsandonedoublebond.
3.2 FuelrelatedProperties
Thepropertiesofcoconutoilrelevantforitsuseasadieselsubstituteare:
SpecificEnergyindicationofthefuelsenergyreleasedwhenitisburned.Coconutoils
energy(38.4MJ/kgor34.9MJ/liter)isalittlelessthanpetrodiesel(46MJ/kgor38.6MJ/liter).
Theenergycontentofoneliterofcoconutoilistypically92%ofthatofoneliterofdiesel.
CetaneNumber(CN)indicationofthefuelswillingnesstoignitewhenitiscompressed.
CoconutoilsCN(60)isthehighest.
Viscosity
indication
of
the
fuels
ability
to
atomize
in
the
injector
system.
Coconut
oils
viscosityiscomparablewithotheroilsbutisseveraltimeshigherthanpetrodiesel.Higher
viscositywillcausepoorvolatilization ofthefuelintheinjectorsystemandpoorspraypattern.
Theviscosityofplantoilssuchascoconutoilcanbereducedbyheating,blendingortrans
esterification.
SolidificationPointindicationofthetemperatureatwhichthefuelwillturnsolid.Coconut
oilssolidificationpointalsocalledfreezingpointisaround24Csoitfreezesduringwinter
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timeeveninsometropicalcountries. Solidificationcanbepreventedbyblendingitwith
dieselorkerosene. Removingtheresidualwaterandfreefattyacidsfoundinmillrefined
coconutoilalsoreducesthefreezingpointtosomeextent.
IodineValue(IV)givesthedegreeofunsaturationofafatandisanindicationoftheability
ofthefueltopolymerizeduetothefuelsdegreeofbondsavailable.CoconutoilsIV(=10)is
thelowestamongalltheplantoilsshowninTable,soitislesslikelytocauseproblemsassociatedwithpolymerisationofaplantoilintheengine.
SaponificationValue(SV)indicationofthefuelsabilitytovaporizeandatomizeduetothe
fuelscarbonchains.CoconutoilhasthehighestSV(268),soitwillignitemorequicklythan
otherplantoils. SVismeasuredbythenumberofmilligramsofpotassiumhydroxiderequired
toconvert1gramoffatintoglycerine/soap.
Table 9 Fuel-related properties of vegetable oils and petroleum diesel
Specific
Energy,Gross
(MJ/kg)
Cetane
Number
Kinematic
Viscosity@
40C(cS)
Solidification
Point
(C)
Iodine
Value
Saponification
Value
PetroleumDiesel
41 49 4555 4 9
CoconutOil 42.0 60 20 24 10 268
PalmOil 39.6 37 35 54 199
RapeseedOil 39.7 38 37 10 125 175
SoybeanOil 39.6 37.9 33 16 130 191
LinseedOil 39.7 29 24 179 190
Source:Bradley,2004
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4 OIL PRESSING & REFINING
Technologiesforproducingcoconutoilfallundertwocategories:
DRYPROCESS Theoilisextractedfromthedriedcoconutkernelcalledcopra. Thiscan
bedoneinlargeoilmills(1000litresoilperhourormore)orinMinimills(10100litresper
hour). Oilmillsaremechanisedandneedtheirownpowersupplytooperatethe
equipment.
WETPROCESS Theoilisextractedfromthefreshkernelaftergratinginitswetorasemi
driedstate. TheRampressandDirectMicroExpeller(DME)havebeenusedtoproduce
VirginCoconutOil(VCO)usinghandoperatedpressessuitableforhouseholdor
communityscale. However,VCOsellsatapricethatismorethandoublethepriceofoil
fromthedryprocess,andisthereforetooexpensivetobeusedasafuel.
4.1 DryProcessandOilRefining
Figure 5 Schematicofdryprocessforcoconutoilextraction
Source:CottorInternational
DriedCoprafromthefarmisstoredinwarehouses,sometimesupto2to3months,beforeitis
processedinamediumorlargescaleoilmillwhereitundergoesthefollowingmainsteps:
Cleaning:Copraistransferredfromthewarehousetoamillbyaseriesoffloorconveyors,
rotorliftandoverheadconveyors.Copraiscleanedofmetals,dirtandotherforeign
mattermanuallybypickingorbymeansofshakingorrevolvingscreens,magnetic
separatorsandothersimilardevices.
Crushing/Cutting:Copraisbrokenintofineparticlesizesofabout1/16"to1/8"byhigh
speedverticalhammermillsorcutterstofacilitateoilextraction;
Cooking/Conditioning:Thecrushedcoprathathasabout56percentmoistureispassed
throughasteamheatedcooker.Thisbringsthetemperatureofthecopratothe
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conditioningtemperatureofabout104oC.Attheconditioner,thecopraismaintainedat
about104110oCforabout30minutestoinsureuniformheatpenetrationbeforeoil
extraction.Moderatelyhightemperaturefacilitatestheexpellingaction.Oilisabletoflow
outmoreeasilyduetodecreaseinviscosity. Moisturecontentofcopraisabout3percent
whenitleavestheconditioner.
Oilextraction:Intheexpeller,themilledcopraissubjectedtohighpressureoilextraction,
firstbyaverticalscrew,andfinallybyahorizontalscrew.Tocontrolthetemperature
duringextraction,themainshaftisprovidedwithwatercoolingandcooledoilissprayed
overthescrewcagebars.Thetemperatureoftheoilshouldbekeptatabout93102oCto
producelightcolouredoilandeffectgoodextraction.
Screening:Theoilextractedintheexpellerflowsintothescreeningtankstoremovethe
entrainedfootsfromtheoil.Thefootssettleatthebottomandarecontinuouslyscooped
outbyaseriesofchainmountedscraperswhichliftthefootstothescreenontopofthe
tank.Whiletravellingacrossthescreen,oilisdrainedoutofthefoots.Thefilteredoilflows
intoasurgetankfromwhereitisfinallypumpedtothecoconutoilstoragetank.
Filtration:Preliminaryfiltrationisdoneinoneofmoresettlingtanks. Theoiltakenfrom
thetopofthesettlingtankispassedthroughaplateandframefilterpresstofurther
removethesolidsintheoil. Maximumfilteringpressuresreachabout60psi.Thefiltered
oilflowsintoasurgetankfromwhereitisfinallypumpedtothecoconutoilstoragetank.
CoconutoilrefiningGoodqualitycoconutoilislowinfattyacidsandhasagoodaromaitcanonlybeproduced
fromgoodqualitycopra.However,afterseveralweeksormonthsinstorageand
transportation,copraislikelytobedark,turbid,highinfreefattyacids(FFA),phosphatides
andgums,andhaveanunpleasantodour.Theoilfromsuchlowqualitycoprahastoberefined
toproduceclear,odourfreeedibleoil. Lossesduringtherefiningprocesscanbe5to7.5
percentoftheweightofthecrudeoil. Themainstepsintherefiningprocessare:
Physicalrefining: Aweaksolutionofphosphoricacidisaddedtoremovephosphatides
andgumswhichareseparatedfromtheoilbycentrifugationorbydecantation.
Neutralisation: Sodiumhydroxideisusedtoconvertfreefattyacidintoanoilinsoluble
precipitatecalledsoapstockwhichsettlesdownandisremoved.
Bleaching: improvesthecolorofcrudeoilbyheatingedtoremoveexcessmoistureand
thenaddingeitheractivatedcarbonorbleachingearthsuchasbentonite. Thebleaching
agentsarethenremovedbypassingtheoilthroughafilterpress.
Deodorisation: removesvolatileodoursandflavoursaswellasperoxidesthataffectthe
stabilityoftheoiltherebyimprovingtheshelflifeoftheoil.Theoilisheatedtoa
temperaturebetween150250oCandcontactingwithlivesteamundervacuumconditions.
MiniMills
Mini Mills can be used to produce coconut oil on a small scale from copra using the Dry
process(10100litresoilperhour). Ifgoodqualitycopraisusedthentherefiningprocessis
not necessary andonlyfiltration isrequiredtoproducefuelgrade oilthat is low infreefatty
acids, moisture and particulates. An excellent discussion on MiniMills is given in the World
BankpublicationCoconutOilPowerGenerationahowtoguideforsmallstationaryengines
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(World Bank, 2009). Details of mills available from manufacturers in China, India and other
countries are provided. Indian MiniMills are designed for copra feedstock but the Chinese
mills,whicharecheaper,aredesignedforsmallerandharderoilseedsandsotheyhavetobe
modified forusewithcopratoavoidjammingtheexpeller. TheWorldBankguideexplainsthe
modificationstobecarriedoutontheChineseMinimillssothattheycanbeusedforcopra.
4.2 WetProcess
Inthewetprocessthecoconutkernelisgratedanddriedtoamoisturecontentofaround12
14%onsheetmetalplatesheatedfrombelow. Atthismoisturelevelitispossibletousehand
operated presses to extract the oil from thegrated coconuts. Two types of equipment have
beenused:
RamPress
DirectMicroExpeller(DME)
4.2.1 RamPress
Rampress(alsocalledBielenbergPress)isamethodofexpellingoilfromarangeofoilseeds
includingdriedcoconuteitherintheformofdriedfreshcoconutgratings,copraordried
residuefromaqueouscoconutprocesses. Inaqueousprocessescoconutmilkisremovedfrom
freshcoconutgratingsleavingbehindcoconutresiduecontaining47%to57%oiland4%
moisture.Thisresiduecannormallybesoldatalowprice,andprocessingitintherampressto
yieldoilcanprovidehigherreturns.
Photo 5 Coconut oil extraction using the Ram Press
Source:CFC,1998
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TheRamPressisamanuallyoperated,semicontinuous,lowcostoilpressdesignedtobeused
bysmallholderfarmers. Itcanbefabricatedandmaintainedbymostvillageworkshopsand
thesmallerversioncaneasilybeoperatedbyindividualwomen.
Feedstockpreparation
Bothfreshlydriedcoconutgratingsandground/gratedcopracanbeprocessedintheram
pressbutthefinancialreturnfromthecoconutresidueishigherthanfromcopra.Thecostof
copraismuchhigherthanthatofcoconutresiduefromtheaqueousprocessandthe
differenceisnotcompensatedbytheslightlyincreasedoilrecovery.
Coconutresiduefromtheaqueousprocessisusuallyallowedtodryoutinheapswithlittle
careorattention.Residuedriedinthismannerproducesoilwithahighleveloffreefattyacid
thatisnotsuitablefordirectedibleconsumption. Inordertoyieldoilofediblequality,the
residuehastobecarefullydriedsoonafterproductionbyspreadingitoutinthinlayersin
directsunlight. Athinlayerofcoconutresiduewillrequireaboutfourhoursindirectsunshine
tobringthemoisturecontentdowntoasatisfactorylevel.
ProductRecovery
Typicallyitispossibletoachieveathroughputof4kgcoconutresidueperhour.10kgsof
residuecanproduce3.9litresofoiland6.1kgofcake. Abouttwothirdsoftheoiloriginally
presentisextractedandapproximately1.65kg(1.8litres)ofoilremainsinthecake.
Oilfromgoodqualitycopra,freshlydriedcoconutgratingsorfreshlydriedcoconutresiduecan
beusedasfuelorconsumedascookingoilorusedforcosmeticpurposes.Poorqualityoilcan
beusedinthemanufactureofsoap. Therampresscakefromcoconutgratings,coconut
residueorcopracanbeusedasacomponentofanimalfeeds.
FurtherdetailsoftheRamPresscanbefoundintheFACTJatrophaHandbookVol.4(FACT,
2009)andintheWorldBankCoconutGuide(WorldBank,2009).
4.2.2 DME DirectMicroExpelling
TheDMEprocessextractscoconutoilfromfreshlygratedcoconutkernelthathasbeendried
toamoisturecontentof912%. ThesemidriedgratedcoconutenterstheDMEequipmentat
atemperatureof45600Cforoilextraction. Filtrationisdonebykeepingtheoilinsettling
tanksforaweek.
TheDMEequipmentconsistsofarackandpinionpresswithinterchangeablestainlesssteelcylindersandpistons,anelectrical orenginepoweredgratingmachineandasurfacedryer.
TheAustraliancompanyKokonutPacificwhodevelopedtheDMEprocessistheonlyknown
supplierofsmallscaleDMEequipmentandtrainingservices. Typically,KokonutPacificDME
equipmentcanprocess3.5kgsofgratedcoconutperbatchtoextractaround1litreofcoconut
oilwithan oilextractionefficiencyofaround80%.Undernormalconditions,itispossibleto
processupto300600nutsdailywithanoutputof2050liters(L)ofoil. EachDMEunit
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requires3to5workers.Skillsrequiredtooperatetheequipmentaresimpleandcanbeeasily
learned.
KokonutPacificisalsotryingtohelpcoconutfarmerssellthevirgincoconutoilfromDMEafter
localdemandissatisfied. Theyensurequality,purchasetheoilfromthefarmersandexportit
toEuropeanandothercountries,muchofitgoingtothecosmeticsindustry. Furtherdetails
canbefoundintheirwebsitewww.kokonutpacific.com.au/.
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5 UTILIZATIONOFLIQUIDBIOFUELS
5.1 CoconutOilfordieselengines
Theuseof vegetableoilsfor enginefuelsmay seem insignificant today.But suchoilsmay
becomein
the
course
of
time
as
important
as
petroleum
and
the
coal
tar
products
of
the
presenttime. RudolfDiesel(1912)
Theuseofplantoilsindieselenginesisasoldasthedieselengineitself. In1896whenthe
inventorofthedieselengineRudolfDieselfirstdemonstratedhisengineinParis,heraniton
peanutoil. However,thedieselengineasithasevolvedtilltodayisoptimisedandmeantto
usedieselfuel,andsoplantoilscoulddamagetheengineifcareisnottaken.
5.1.1 InternalCombustionEngines
Internal combustionengines (IC engines)now power most of our land and sea transportandsomeofourairtransportandpowerplantsaswell. ICenginesareclassifiedprimarilybythe
methodofignitionused:
a) Sparkignition(SI)enginesthatgenerallyusegasoline/petrolasfuel;theseenginesareusedinautomobiles, smallboats,aircraftandsmallelectricitygeneratingsets;naturalgas
enginesarealsoSI.
b) Compressionignition(CI)enginesthatgenerallyusedieselasfuel;theseenginesareusedinmediumandheavydutytrucksandbuses,smallerautomobiles, boatsandships,and
dieselpowerplants.
Therearetwotypesofliquidfuelsderivedfromplantsthatcansubstitutegasoline/petroland
diesel:
Ethanolproducedfrom:sugar(sugarcane,sugarbeet),starch(maize,cassava),or
cellulose(bagasse,straw,wood).
Plantoilssuchasrapeseedoil,sunfloweroil,cottonseedoil,coconutoil,etc.and
theirderivativessuchasbiodieselproducedbyesterificationoftheseoils.
WhilethetechnologyforusingethanolinbothSIandCIenginesiswelldeveloped,pureplant
oilandbiodieselcan,atpresent,beusedonlyinCIengines. Inthissectionwelookattheuse
ofcoconutoilinCIengines. Section5.2looksbrieflyatbiodieselproducedfromcoconutoil.
Averygooddescriptionofthecomponents,fuelsystemandhowthecompressionignition
engineworksisgivenintheWorldBankpublicationCoconutOilPowerGenerationahowtoguideforsmallstationaryengines(WorldBank,2009).
5.1.2 FuelInjection
While using pure coconut oil in CI engines, it is very important to understand the difference
between direct injection and indirect injection engines, and the advantages that an Indirect
injectionenginehasoverDirectinjectionsothattheengineisnotdamaged.
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c) Ensuring that the temperature in the combustion chamber is high enough (above
500oC).
Photo 6 Effectsofimpropercombustionofcoconutoilinengine
a) Carbondepositsonthenozzleandvalves b)Mechanicaldamageonpistonringsand
cylinder
Source: Vaitilingom,2009
DecreasingViscosityofCoconutOil
The viscosity of coconut oil can be decreased by using a simple shellandtube type heat
exchangerthattakeshotradiatorwatertowarmupthecoconutoil. The innercoiledpipe is
made of copper to facilitate good heat transfer while the outer cylindrical shell is made of
steel. Photo shows the components of the heat exchanger and when it is fitted in a car.
(Deamer,2005)
Viscocityofcoconut oilcanalsobedecreasedbyblendingitwithkerosene. TonyDeamerof
Vanuatu has found that a blend of 85% coconut oil and 15% kerosene works very well with
dieselengines. WiththisblendwhichhecallsIslandFuel,theheatexchangerisnotrequired,
buthestill recommends it. TheIslandFuelblend also makessure that coconut oildoes not
freezeinthefueltankataround20oC. SeeSection5.3.1formoredetails.
Photo7 Heatexchangerusedforconversionofcarstorunoncoconut oil
(a)ComponentsoftheHeatExchanger (b)HeatExchangerfittedinacar
Source:TonyDeamer
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CombustionTemperature
The temperature in the Combustion Chamber has to be high enough (above 500oC) for the
coconut oil to burn fully. Indirect injection engines have temperatures above 500oC
irrespective of the load, and so coconut oil can be used safely in these engines even at low
loads.
Figure 8 Effect of chamber temperature on combustion of coconut oil
IfTemperatureinCombustionChamber islow
(50%;
Indirect
injection
engines
at
any
load
Source:Vaitilingom,2009
2tanksystemforaDirectinjectionengine
Since Direct injection engines have temperatures above 500oC only at high loads, to ensure
complete combustion of the fuel a 2tank system must be used so that the engine is run on
diesel fuel whenever the load is below 50%. Figure9 shows one way of doing this using a
solenoidvalveforfuelswitching.
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Figure 9 A 2-tank system for using Coconut Oil in a Direct injection engine
Photo 8 Auxiliary equipment used with a 2-tank system
Solenoid Valve Heat Exchangers
Control Module Coconut oil Pump Coconut Oil Filter
Coconutoil
DieselFueltank
Filter
2x3wayssolenoid
Filter,heatexchangerandpump
engine
EXAMPLE OF A 2-TANK SYSTEM
Exhaustgastempprobe
Controlmodule
RPMsensor
Bypass
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Source:GillesVaitilingom
ApplicationsofDieselengines
Dieselenginesareusedmainlyfortwoapplications:
1. Stationerydieselenginescoupledwithgeneratorsforpowergenerationrefertothe
WorldBankCoconutGuidefordetails(WorldBank,2009).
2. Automotivedieselenginesfortrucks,buses,carsandshipsrefertoSection5.3.1for
details.
5.1.3 QualityStandardsforCoconutoil
The three most important parameters of coconut oil that need to be controlled for use in
dieselenginesare:
1) Freefattyacids,
2) Water,
3) Particulatematter.
FreeFattyAcids(FFA)andWater:Normal factoryproducedcoconutoilcontainsaround4%water and2to3%FreeFattyAcids
(FFAs). These contaminants cause the oil to solidify when the temperature of the oil drops
below 22oC,which isquitecommon duringwinter intheSouth Pacific. Oneway aroundthis
problemistoblendtheoilwithsomedieselfueltopreventsolidification.Thepresenceofthe
dieselfuelalsoaidscoldstartingwhentheambienttemperatureisbelow20oC.
TheotherproblemwithFFAsisthattheyblockthefuelfilterwhenthefuelsystemiscold.This
canbeovercomebyfittingasmallheatexchangerinthefuellinetowarmthefuelpriortothe
fuel filter. FFAscan alsobe neutralized withanalkalisuchassodiumhydroxide (NaOH).The
removal of water andFFAseliminatesthe solidificationof the fuel at 20oCand gives the fuel
greatercalorificvalue. Moreover,afterthewaterandFFAhavebeenremovedfromtheoil,it
hasbeenfoundthatthefuelpreheaterisnotrequired. (Deamer,2005)
ParticulateMatter
Particulates choke up the fuel filters. Even though a second fuel filter with a bypass valve is
normallyaddedontoadieselenginethatrunsoncoconutoil,particulateshavetobereduced
to a manageable level. Since diesel fuel filters normally filter upto 10 microns, a 10 micron
filter for coconut oil will prevent the fuel filter on the genset or automobile from clogging
rapidly. This canbe done by a Bag Filter as shown in Photo (Vaitilingom, ). It can also be
donebyusingaultrahighspeedcentrifuge(Deamer,2005).
AtpresenttherearenointernationallyacceptedQualityStandardsforCoconutOilasaFuelin
engines. Some standards proposed by Dr. Gilles Vaitilingom of the French research center
CIRADbased onhisexperience isgiven inTable . TheFijiDepartmentofEnergyandtheFiji
InstituteofTechnologyarecarryingoutsometeststoverifytheseDraftStandards.
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Table 10 Draft Quality Standards for Coconut Oil as a Fuel in engines
Quality standard for Coconut oil as fuel (proposal)
Properties/content Unit Min. Max. Test method
Characteristic properties
Density at 25C Kg/m3
0,915 - ASTM D1298
Flash Point C 210 - ASTM D93
Calorific value MJ/kg 37 -
Viscosity (Kin. @ 40C) mm2/s - 30 ASTM D445
Carbon residue Mass % - 0,40 ASTM 4530
Sulphur content mg/kg - 20 ASTM D5453
Cetane Index 40 - ASTM D4737
Variable properties
Total contamination mg/kg - 25 ASTM 5452
Acid value mg KOH/g - 10 ISO 660
Oxidation stability(110C)
h 4 ASTM D2274
Phosphorous content mg/kg - 15 ASTM D323
Ash content Mass % - 0,02 ISO 6245
Water content Mass % - 0,075 ISO 12937
Source: Vaitilingom,2008
5.2 Biodiesel
AhighcetanenumberandalowiodinenumbermakescoconutoilwellsuitedforCIengines,
butithastwomaindrawbacks:ahighmeltingpointandhighviscosity,bothofwhichcanbe
correctedbyesterifyingtheoilintobiodiesel. Biodieselmadefromcoconutoilby
transesterification,whichisalsocalledCoconutMethylEster(CME),hasameltingpointthatis
belowzerodegreeCanditscetaneandiodinenumbersarenearlythesameascoconutoil.
CMEhasotheradvantagesovercoconutoil itsviscosityandotherphysicalpropertiesare
similartopetroleumdieselsoitcanbeeasilymixed,transportedanddistributedwithdiesel,
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anddieselenginesdonotneedanymodification forusingblendsofbiodiesel. Formore
detailsaboutbiodieselreferBiodieselHandlingandUseGuide(NREL,2006)
PhilippineshasagovernmentsupportedprogramtoproduceCoconutMethylEster(CME)
fromcoconutoilandblenditwithdieselfuel. ThephysicochemicalpropertiesofCME
producedinthePhilippinesanditsblendswithdieselhavebeenmeasured. Resultsare
comparedinTable11withPhilippineNationalStandardfordieselfuelquality(PNS2020:2003)
andbiodieselproducedfromSoyabeanoil.
Table 11 Physico-Chemical properties of Coconut Methyl Ester (CME)
Source: AllemanandMcCormick,2006
Themainfindingsofthesetestswere:
CMEaswellasCMEblends(1%and5%byvolume)metthecurrentPhilippineNational
Standardfordieselfuelquality.
The5%blendofCMEindieselfuelincreasedthecetanenumberslightlyforeach
blend. ThedieselfuelsandtheCMEdieselblendsdidnottakeupsignificantamountsof
water,norwerestableemulsionsformedforanyofthefuelsorfuelblendstested.
TheCMEsample,thedieselfuelsamples,andthe5%CMEdieselblendsexhibiteda
similarlevelofstability.Thetestresultsshowedfewinsolublesweregeneratedduring
thetests,whichunderstorageconditions,maycontributetopoorengineperformance
duetopluggedfuelfiltersorcloggedinjectors.
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Sixteenindicatorsofmicrobialdegradationweremeasured. Theresultsshowedthat
theCMEsampleandtheneatdieselfuelsampleshavesimilarresistancetomicrobial
degradation,althoughthemechanismsfordegradationmayvary.
AFourierTransforminfraredtechniquewasfoundtobehighlylinearandcanbeused
toquantitativelydeterminethepercentageofCMEinadieselfuelsample.
(AllemanandMcCormick,2006).
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5.3 CasestudiesinPacificandlessonslearned
5.3.1 Islandfuel,Vanuatu
OneofthepioneersinusingcoconutoilindieselvehiclesisTonyDeamer,anAustralianwho
livesinVanuatuinthesouthPacific. Fornearlytenyearshehasbeenexperimentingwith
usageofcoconutoiltorundieselautomobilesandhasnowarrivedatamixthathesellsunder
thenameofIslandFuelwhichcanbeusedindieselengineswithoutanymodifications
(Deameretal,2005). Hestartedbyusingnormalfactoryproducedcoconutoilthatcontains
around4%waterand2%to3%FFAs(FreeFattyAcids). Hefoundthatthesecontaminants
causetheoiltosolidifywhenthetemperatureoftheoildropsbelow22oC,whichisquite
commonduringwinterintheSouthPacific. Onewayaroundthisproblemistoblendtheoil
withsomedieselfueltopreventsolidification.Thepresenceofthedieselfuelalsoaidscold
startingwhentheambienttemperatureisbelow20oC. TheotherproblemwasthattheFFAs
blockedthefuelfilterwhenthefuelsystemwascold.Thiswasovercomebyfittingasmallheat
exchangerinthefuellinetowarmthefuelpriortothefuelfilter.Thewaterfortheheat
exchangerwastakenfromthethermostatbypasscircuitsothatitwaswarmwithinaminute
orsooftheenginestarting.Thiseliminatedthefuelfilterblockages.
TonyDeamernowusesaproprietaryprocessthatremovesboththewaterandtheFFAsfrom
thecoconutoil. Thefuelisthenfilteredthrougha3micronfilter. Theremovalofwaterand
FFAslowersthesolidificationtemperatureofthefuelandraisesthecalorificvalueofthefuel.
Moreover,afterthewaterandFFAshavebeenremovedfromtheoil,ithasbeenfoundthat
thefuelpreheaterisnotrequired.
Photo9 IslandFuelFillingStation
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Source:TonyDeamer
Deamerhasbeenoperatinghisfleetofvehiclesonvariousblendsofcoconutoilanddieselin
severalratios,andalsoonacoconutoilandkerosenemix. Heeventried5%methanolfora
timebutfounditevaporatedouttooquickly,sointheendhedecidedtostickwiththeproven
15%keroseneblend. TonyDeamersIslandFuelmadeinVanuatucontains85%ofthe
purifiedandfilteredcoconutoilblendedwith15%kerosene. Nomodificationsarerequiredin
thedieselenginesthatuseIslandFuel;however,enginepreheatersarerecommendedfor
colderareas.
TonyDeamersaysthatthisfuelhasbeentriedandtestedovermanyyearsandisnowready
forretailsale. Unfortunately,thelawsofVanuatudonotallowthesaleofIslandFuel,sohe
sellsonlythecoconutoiltointerestedcarowners. TheminibusfleetownersinPortaVilahave
beenblendingtheirownIslandFuelsince1995.Thebusoperatorsarecompletelysatisfied
withusingitandtheyarereportinganincreaseinkilometersperlitrewhenoperatingwiththe
IslandFuel.
Basedonhisexperiencewithproducingfuelgradecoconutoilandblends,andinusingthemasfuelsinallhisvehicles,TonyDeamerhasfoundthat:
a) Coconutoilhasbetterlubricatingqualitiesthanotherfuelsfordieselenginessoitcauses
lesswearoninternalenginepartsandprolongsenginelife.
b) Coconutoilburnsslowerthanotherdieselfuelssoitpushesthepistonallthewaydown
thecylinderinsteadofarapidexplosionatthetopofthestroke,resultinginaneven
powerrelease,lessfueluse,lessenginewearandaquieterrunningengine.
c) Coconutoilfuelleddieselenginesruncoolerduetolessinternalfrictionandtheslower
burnrate.
d) Coconutoilisnotanidealsubtropicalfuelasitwillsolidifyovernightiftemperaturesdrop
below24degreesCelsius.However,thegelpoint(thepointatwhichitbecomessolid)can
begreatlyreducedbymixingthecoconutoilwithkeroseneorbykeepingthefuelheated
usingheatingaccessoriescommonlyfoundongenerators,boatsandtransportvehicles.
e) Coconutoilbasedfuelsyieldover10%morekilometersperlitre(km/l)usedthan
petroleumdiesel. Datacollectedovera20,000km,6monthtestonanIsuzuDirect
injection2.5ltr4JAIdieselmotorinapickupthatwasgivinglessthan12km/ldiesel,
showedthatithadimprovedtoapprox13.5km/Ion"IslandFuel60".
f) AnoticeabletorqueincreaseisfeltwithIslandFuel. Itwasnoticedthat,whiledriving
uphill,achangedowntothenextgearwasoftennotrequiredastheenginekeeppullingat
thelowerRPM. Thisiseasilyexplainedbythefactthatthecoconutoilburnsslowerthan
diesel.
g) Theexhaustfumesfromcoconutoilarelessharmfulthanmineralbasedfuels. Whenburntinadieselengine,cocodieselemits50%lessparticlematter(blacksmoke)andless
sulfurdioxide(SO2). Exhaustfromcoconutoilcontainsnopolyacrylichydrocarbons
(PAH's) themaincancer causingcomponentofmineraldieselfuelexhaust.
h) Coconutoilisnontoxicandfullybiodegradable. Itissafetostoreandtotransport.Oil
spillsonlandorwaterareharmlessandthereisareducedriskoffire.Nochemicalsare
requiredtoproducethefuelsotherearenoharmfulbyproducts.
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i) Theentireprocessofmakingcoconutbasedfuelfordieselenginescanbedoneinthe
islandscreatingjobsandstimulatingtheeconomy. Alltheincomefromtheproduction
andsaleofcoconutoilstaysintheislandsinsteadofgoingoverseas.Ahighpercentageof
theincomefromcoconutbasedfuelswillgotothelocalfarmersinruralareas.
j) Allthestepsintheproductionofcoconutoilcanbefuelledbycoconutoilorcoconut
residuessothereisnoadditiontogreenhousegasesduringtheproductionofthefuel
product.
k) Onthenegativeside,somedriversandpassengersofthecoconutoilblendpowered
vehicleshavereportedheadachesiftheexhaustgasleaksintothepassenger
compartment.TheMotorTradersfleethavemadechangestotheexhaustsystemtoclear
theexhaustgasesfromthevehicle.Thenatureoftheheadachecausingagentneedstobe
determinedandifagreaternumberofvehiclesareoperatinginanurbanareaitwillneed
tobedeterminedifthisagentwillcauseproblemsforthegeneralpublic.
[Deameretal,2005]
Photo10 RangeRoverandToyotaRunningonVanuatuCoconutOil
Source:
Tony
Deamer
SomeoftheadvantagesofIslandFuelare:
Environmental Advantages
1) Coconutoildoesnotcontributetothegreenhouseeffect.Whenburnedinadiesel
engine,coconutoilreleasesthesameamountofcarbondioxide(CO2)thatwillbe
consumedbythenextbatchofcoconuts.Inthisway,thecocodieselcyclescarbon
throughtheatmospherefromplanttotheairandbacktotheplant.
2) WhenburntinaDieselengine,cocodieselemitslesssulfurdioxideSO2(theprimary
contributortotropicalplantandrainforestdepletion).
3) Coconutoilemits50%lessparticlematter(blacksmoke)thanconventionaldiesel.
4) Nochemicalsarerequiredtoproducethefuelsotherearenoharmfulbyproducts.
5) Allthestepsintheproductionofcoconutoilcanbefuelledbycoconutoilfuelsothere
isnoadditiontogreenhousegasesduringtheproductionofthefuelproduct.
6) Coconutoilisbiodegradable.
Economic Advantages
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1) CoconutoilbasedfuelsyieldmoreKmperlitreusedthanotherfuelsfordiesel
engines.
2) Thecostofcoconutoilispresentlyloweronthanthecostofotherfuelsfordiesel
enginesinVanuatu.
3) Theentireprocessofmakingcoconutbasedfuel fordiesel enginescanbedonein
Vanuatucreatingjobsandstimulatingtheeconomy.
4) AlltheincomefromtheproductionandsaleofcoconutoilstaysinVanuatu,insteadof
goingoverseas.SothetaxreceivedfromVATeach time themoneyisspentlocally
willexceedtheincomederivedfromthedutyontheimportedproduct.
5) Ahighpercentageoftheincomefromcoconutbasedfuelswillgotothelocalfarmers
inruralareas.
MechanicalAdvantages
1) Coconutoilhasbetterlubricatingqualitiesthanotherfuelsfordieselenginessoit
causeslesswearoninternalenginepartsandprolongsenginelife.
2) Coconutoilburnsslowerthanotherdieselfuelssoitpushesthepistonalltheway
downthecylinderinsteadofarapidexplosionatthetopofthestrokeresultinginanevenpowerrelease,lessfueluse,lessenginewearandaquieterrunningengine.
3) CoconutoilfuelledDieselsruncoolerduetolessinternalfrictionandtheslowerburn
rate.
Safety Advantages
1) Theexhaustfumesfromcoconutarelessharmfulthan mineralbasedfuels. Exhaust
fromcoconutoilcontainsnoPolyAcrylicHydrocarbons(PAH's) themaincancer
causingcomponentofmineraldieselfuelexhaust.
2) Coconutoilissafetostoreandtotransport.Oilspillsonlandorwaterareharmless
andthereisareducedriskoffire.
3) Coconutoilisnontoxicandfullybiodegradable.Afterall,whatotherfuelcanyouboth
cookyourfishandchipsinandrunyourtruckon??
Disadvantages
Coconut oil is not an ideal sub tropical fuel as it will solidify overnight if temperatures drop
below14degreesCelsius.However, thegelpoint(thepointatwhichitbecomessolid)canbe
greatlyreducedby mixingthecoconutoilwith Kerosene orbykeepingthefuel heatedusing
heatingaccessoriescommonlyfoundongenerators,boatsandtransportvehicles.
Commentsonmotorperformance
DatacollectedontheIsuzuDirectinjection2.5ltr4JAIdieselmotorinapickupovera20,000km6monthtestshowedanaverageof12.75kmperlitreon"CocoDiesel".This
hasimprovedon"IslandFuel60"toapprox13.5Km/I. OnDieselthevehiclewas
achievinglessthan12Km/I.(AFullsheetofallfuelusedandKmdrivenwithcomentsis
available.)
TheTwoToyota"L"and"2L"2.2and2.4ltrenginesonlyaveraged7.5Km/l.onCoco
dieselandabout8Km/lon"IslandFuel60". Topendhorsepowerwasslightlydown.
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i.e.accelerationwasnotsobriskon"CocoDiesel60/70butalmostnormalon"Island
Fuel60".Anoticeabletorqueincreasewasfelt. Itwasnoticedthatachangedownto
thenextgearwasoftennotrequiredastheenginekeeppullingatthelowerRPM.
ThisiseasilyexplainedbythefactthattheCoconutoilburnsslowerthantheDiesel
(i.e.moreora"WhooshandlessofaBang").
After12monthsofuseonUnprocessedCocoDiesel(NotIslandFuel)aNissanLD28
2.8ltrnaturallyaspirateddieselengineoperatingwithinaRangeRoverwasstripped.
Thepistons,rings,bearings,valvesandinjectorswereremovedforexamination. All
wereinmuchcleanerandbettershapethanexpectedfromadieselengine.Thebore
marksstillshowedthecrosshatchhonemarks,thevalvesandcamgearwasallclean
andinperfectorder. Theonlyproblemwasthattheenginewaspurchasedsome10
yearsagosecondhandsoTonydoesnotknowhowitwasusedinthepast. Buthe
guessesthatithadatleast100,000Kmbeforehegotitandapprox30,000Kmfromthe
timehehadittothetimehestartedusingCocoDieselinit. Themotorwasputback
togetherwithnewpistons,ringsbearingsandinjectorsnozzlesandanewtimingbelt.
Itisnowusing"IslandFuel60"inwinterand"IslandFuel70"duringwarmerweather
inthesummermonths.
At the start of 2003 Deamer ordered his own Processing Equipment and continued to make
and supply processed coconut oil only, to anyone wanting it, and left it to them to mix their
ownpetroleumproductwithit.
InhisownUnitshetriedmixingMethanolat5%foratimebutfounditevaporatedouttoo
quickly. Sointheendhedecidedtostickwiththeproven15%keroandsosince2003 the
RangeRoverandallourotherUnitshavebeenrunningonthismixaswastheVolvofrom
thestartoftheexperimentin2001.
In2005ColdpressedCrudecoconutoilwassellinginSantofor65Vatualitre(approx
US$0.59perltr). Dieselwas132Vatuatthepumps CNOrefinedsoldforabout90Vatua
ltr. andtheKerowasat120Vatu soaBlendedfuelcostapprox95Vatuper ltr.
DeamersvehicleshavenotexperiencedanyCNOrelatedproblemsinthepastfewyears.
TheydidreplaceaHeadGasketontheVolvoduetoanoverheatingproblemthatresulted
intheenginerunningdryofwaterforalongperiod,butitdidnotseizeup.
BothVolvoandRangeRoverarerunninganLD28NissanenginewithPercombustion
chambersandtheyarenotDirectinjection.
TheIsuzu withDirectinjectionengine2/5ltrisnowonthe15%keromixandtheyareno
longerhavingtheboreglazingproblemstheywerehavingwhendrivenlightlyonthe
60/40CNO/Dieselmixinthefirstyearoftheexperiments.
5.3.2 Cocogen,Samoa
TheSamoanElectricPowerCorporation(EPC)hasbeenlookingintoalternativesfordieselfuel
electricitygenerationincludingbiofuels,solarandwind. Intheearly1980s,EPChadcarried
outtrialsonusingcoconutoilfordieselengineoperationoveraperiodofsixmonths,butno
recordsorresultsofthesetestsareavailabletoday.Becauseofthetechnicalrisksassociated
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withusingfuelsthatarenotrecommendedbythemanufacturerofthegeneratingunits,these
trialswerenotcontinued.
From20022005EPChasgeneratedalittleover120GWh/yrofwhichroughlyhalfisfrom
hydropowerandtheotherhalffromdieselpowerplants. Thecurrentbaseloaddeliveredby
thedieselpowerstationisapproximately8MW,withamorningpeakof13andanevening
peakof17MW.
Throughacombinationofcostsavingsandenvironmentalconsiderations,EPCaimstoutilise
alternativefuelsfromdieselwillbeapart.Inaddition,theincreasingdependenceonimported
fossilfuelsisanothermainreasontocarryoutafeasibilitystudyintotheuseofalternative
fuelsintheEPCgenerators. Byaimingforapartialdisplacementofdieselfuel,EPCcangain
valuableexperiencebasedonwhichfurthersubstitutioncanbeconsidered.Thepricevolatility
onboththecoconutoilmarketandthefossilfuelmarketdonotsupportthecompleteswitch
tococonutoilfuel.
Dr.GillesVaitilingom, theBiofuelSpecialistintheCOCOGENteamfoundthatnoneofthegensetscurrentlyrunningatTanugamanonoorSalelologaPowerStationscouldusestraight
coconutoilasfuelwithoutchemicaltransformationsoftheoilormechanicalmodificationsof
engines. However,basedonhisexperiencewithrunningdieselgensetswithpureplantoils
includingcoconutoil,hepredictedthattherewerehighchancesofsuccessforusinga10%
blendofcoconutoilwithdieselfuel,iftheloadonthegensetiskeptover50%ofitsrated
load. Incasebadcombustionoccurs(misfiringorcyclicaldispersion)theamountofunburnt
fuel(blendofcoconutoilanddiesel)wouldbehigherthan1/1000.Thatmeans,outofthe
10,000litresoftheblendusedinthetest,10litreswouldremainunburnt,andthis10litres
wouldcontain1litreofcoconutoil. Inasumpofaroundthan100litresoflubricantcapacity,
thiswillleadtoapollutionofthelubebytriglyceridesandfattyacidsof1%,andthislevelof
contaminationiseasytodetectaccurately. Iftheanalysisofthelubesamplesrevealthatthe
levelofcontaminationbyunburntcoconutoilislessthan1%,itcanbeconcludedthatthe
combustionwasgoodand,thatforthisgenset,underthecurrentoperatingconditions,a10%
blendofcoconutoilcanbeusedsafely.
Photo 11 CumminsDirectInjection400kWDieselEnginetestedwith10%coconutoil
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Source:SOPAC,2005
SpecificationsoftheDieselGeneratingSet
Usage(Feb05) 179hrs
PercentofProduction 4%
EngineMaker Cummins
EngineModel KTTA19G2
EngineSerial# 37155000
SONo 62222
CPL 1170
HP/RPM 1500rpm
ManufacturingDate 8/11/94
RatedSpeed 1500
IdleSpeed 800(low)
#ofCylinders 6
Bore[mm] 158.75
Stroke[mm] 158.75
Type 4cycleverticalinlinecylinder
CoolingSystem WaterRadiator
CompressionRatio 13:8:1
Aspiration Turbo/cooled
Displacement[l] 18.7Rotation(flywheel) CCW
InjectionMethod CommonRailHVT
TypeofNozzle DirectInjectionHoleType
TypeofFuel BS2869A1
Governor Electric
StartingMethod Electric24V
Maker ONAN
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GeneratorModel 450DFFB
SerialNumber A92A001721
Rating Standby
Spec 5673G
KVA 563
Amps 783
KW 400
KW(derated) 250
Volts 415
AfterconsultationwiththeGeneralManager,itwasagreedthattestswith10,000litresofa
10%blendpilotwouldbecarriedoutwithengine#2A,comprisingof1,000litresofcoconutoil
blendedwith9,000litresofdieselfuel. Forthepilot,thefollowingrisks(andriskreduction
strategies)wereidentified:
NoCoconutoilavailable; ContactedandvisitedCOPStorequestthedeliveryofoilfrom
currentproduction.
BadQualityCOPSoil; Prefilteringofoilwithexistingfuelfilterstoavoidparticlesinthe
fueltank.
CarbonDeposits; Themachineshavetoberunabove50%oftheirratedcapacityto
avoidexcessivecarbondeposits.Withthederatingofthemachines,thismeansthey
shouldrunatmaximumpower.
Filterclogging; Ifcoconutoilismixedwithwaterbyaccident,theresultingmixturecan
leadtocloggingoffilters,therefore,goodworkinghygieneisrequired.
Blendpercentagenotright; Asthepilotisdesignedtominimisetheriskforthe
machines,itisimperativethattheoperatorstickstothe10%blendofcoconutoiland90%
regulardiesel.Forhigherpercentagesofcoconutoilinthefuel,engineadaptationsmaybe
required.
Lubeoilsamplenotright; Itisimperativethatthesampleofthelubeoilafterthetestis
takenaccordingtoinstructionssothattheanalysiscanbecarriedoutcorrectly.
Inordertoreduce these risks, the technicalconsultant was presentto instructthe operators
on the first day of the pilot test. Secondly, clear working instructions for the pilottest were
provided:
WorkingInstructionsfortheCoconutOilPilotTest
Engine:
Lubricant
and
oil
filters
must
be
new
or
having
less
than
250
running
hours.
Fuel: Atotalvolumeof10,000litreswillfeedengine2A.Itiscomposedof1,000litresof
coconutoiland9,000litresofdieselfuel.Themixturewillthenbepreparedas1volumeof
coconutoilplus9volumesofdiesel.Thiswillrequirethefollowingsteps:
1) Pour1volumeofcoconutoilinthedailytank;
2) Pour9volumesofdieselfuelinthedailytank;
3) Stirthedailytankfor2minuteswithastick.
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Lubricant:1) Thesamelubricantwillbeusedduringthedurationofthetest.
2) Addedvolumeoflubricantmustbeloggedexactly.
3) Twosamplesoflubeoilwillbecollectedinthesumpofthetestengineandsentto
SOPAC/Fiji:(a)onesamplebeforestartingthetest,and(b)thesecondsampleafter
completionofthetest.
Operationofthetestgenset: TheGeneratorSetbeingtestedmustnotbeusedunder50%ofitsoriginalrating,i.e.200kW.Thegensetcanonlybeallowedtorunforuptoone
houronaloadbelow200kW,afterwhichitmustbeshutdown.
Mechanical: Incaseofamechanicalinterventionontheengine,collectasampleoflubeoilbeforestartingagain.Thissamplewillbejoinedwiththesampletakenattheendofthe
test.
DatarequiredTheLogbookmustcontain:AttheStartofthetest:
1) Typeoflubricant;
2) Gradeoflubricant;
3) #ofrunninghoursofthelubricantinthesump;
4) Collectofthesampleoflubeoil.
Daily:
1) Date;
2) #ofkWh;
3) #ofrunninghours;
4) Volume
of
blend
used;
5) Volumeofaddedlubricant;
6) #ofstartsduringtheday;
7) Observation/troubleshooting.
AttheEndofthetest:
1) Collectofthesampleoflubeoil;
2) Indicatethenumberofrunninghours;
3) Completethedailylogbook;
4) SendthesampleandthelogdatasheettoSOPACinFiji.
Immediatelyafterthefieldwork,lubeoilsamplesbeforeandafterthepilotweresentthrough
tothelaboratoryoftheUniversityoftheSouthPacificinFijiandtoaspecialisedlaboratoryin
France.Thelubeoilanalysespointedthatnoharmfullevelofcontamination of(unburnt)
coconutoilcouldbedetectedinthelubricant.Therefore,thetestcanbedescribedas
successfulandtherecommendationsoftheSalelogaPowerStationmanagercanbefollowed
tocontinuethepilot.TheCocogenteamproposescontinuationoflubeoilanalysisatregular
operationintervals.
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Photo12 FilteringofCoconutOilwithaSheetBeforemixinginthedaytank
Source:SOPAC,2005
Testingofa10,000litresBlendof10%CoconutOil+90%DieselFuelinGenset2ATest:TheteststartedonSaturday2ndofApril2005inthepresenceofDrVaitilingom. He
recommendedstronglythattheloadoftheengineshouldnotbebelow80%ofnormalload.
Forthisengine,thenormalloadis200kWandthereforetheloadshouldbeabove150kWat
anytime.Iftheloadisbelow150kW,thentheenginemustbeshutdowntoavoidanysignof
unforeseenfailure.Thetesttookabout3weekstocomplete6x44gallonsofcoconutoilthat
isonApril23,2005.
ResultsoftheTestsBetweenApril2andApril232005,atotalof1,018litresofcoconutoilwasblendedwith9,167
litresofdieselinthedaytankofengine#2inSalelogaPowerStation.Theoverallfuelusage
forthetrialengineforthewholemonthofAprilwas17,162litres.Totally10,185litresofblend
wasusedduringthetest.
ThelubeoilsamplesafterthetestweresenttolabsinFijiandtoFranceforanalysis.Thelevel
ofcontaminationofthelubeoilbyunburntcoconutoilindicatedthatitwasadvisableto
continueusingacoconutoilblendinmachine#2.
Statistics:Durationoftest(days): 22
Amountofcoconutfuelused: 1,000Litresapproximately
Amountofhoursduringtest: 245
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Averagehourperday: 11
TopupOilduringtest: 26litres
TotalkWh: 46,278kWh
Comments:Thesuccessfulcompletionofthetestrevealspositivedirectionofcoconutoilasanalternative
fuel, provided that it is less expensive that diesel fuel. Mechanically speaking, there was no
signofanydefectduringthetest.
Recommendations:1) Thetestisnotlongenoughtofindouttheimpactofthetesttoenginecomponents.It
issuggestedofatleast1,000hrsofrunningisappropriate.
2) After1000hrsoftest,theengineshouldbeinspectedwiththoroughchecksonits
cylinderheads,injectors,liners,pistons,pistonrings,andfuelpumpetcforany
abnormalsignsordefects.
3) Theexhaustgasduringthistestwasnotsatisfactoryandthereforesuggestedstrongly
thattherecommendedsulphurcontentofthefuelshouldbebetween0.25and0.50percentagebyweight.
Thefinancial,economicandenvironmentalimpactsoftheCocogenprojectaregiveninthe
FinalReport(SOPAC,2005). ThisreportalsocontainsdetailsoftheGISstudy(Geographical
InformationSystem)usedtoassesstheCoconutResourcesofSamoa.
5.3.3 CoconutoilforpowergenerationinFiji
CoconutsaregrownonalltheFijianislands. Coconutoilisalocalresourcethatisabundantly
availableespeciallyintheruralcoastalcommunities.Aprojecttousecoconutoilforvillage
electrificationwasplannedin199899jointlybyFijiDepartmentofEnergy,theSecretariatof
thePacificCommunity(SPC)andCIRAD. Thetechnicalexpertiseandtechnologywere
providedbyCIRADFrancethroughFrenchGovernmentfunding.TheMinistryofAgriculture
(TaveuniCoconutCentre)andPublicWorksDepartment(Electrical)werevitalpartnersinthe
projectimplementationwhichcoveredfourvillages.
Theprojectinvolvedthemodificationoftwodieselgensetsofcapacities45kVAand90kVAso
thattheycouldrunonpurecoconutoil. Twositeswerechosenfortheproject:
1) Lomaloma,NaqaraandSawanavillagesinVanuaBalavuand
2) WelagivillageinTauveni.
CIRAD had already successfully installed three diesel gensets modified for coconut oil on the
islandofOuvainNewCaledonia:
1. In1995a90KVAgensettoprovideelectricityforacopramillwithacapacityof350
kgcopraperhour.
2. In1999one180KVAandone45KVAgensettoprovideelectricityforadesalination
plant.
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The coconut oil gensets that CIRAD provided for Fiji were identical to the ones that CIRAD
installedinNewCaledonia:
These gensets were designed for fully automatic operation after a push button start
evenattemperaturesbelow24oCwhenthecoconutoilisfrozen.
Thereweretwofueltanksonefordieselandtheotherforcoconutoil.
Thegensetisstartedandstoppedondieselfuelfor10to15minutes.
The coconut oil tank had electricheaters below thetank to melt the coconut oil and
also an electric heater in the well of the tank where the outlet pipe emerged. Once
the coconut oil had been heated to the required temperature the control system
switchesthefuelsupplytococonutoilbymeansofasolenoidvalve.
Coconutoilisutilizedastheprimaryfuelsourcefor90% 95%ofthetotalrunning
timeofthegenerator.
Asecondextrafuelfilterisfittedwithabypassvalve.
Alargerfuelpumpisfitted.
Yearlyinspectionsarecarriedoutontheprojectsitesforrepairsandtrainingof
technicianstorunthegenerators.
Welagi
The45kVAWelagiCopraBiofuelProjectwascommisisioned inJuly2001,anditrantrouble
freeforafewyearsafteritsimplementation.Thisprojectservesavillagewith58households
andoilproductionisthroughasmalloilmillthatwasbuildaspartoftheproject. Thevillage
hasaspecialcommitteethatlooksaftertheaffairsofthecopraproductionandsubsequentoil
productionthat
are
used
to
generate
electricity
in
the
biofuel
generator.
Photo9showstheequipmentinstalledinWelangiforproducingfuelgradecoconutoil. Copra
cutintosmallpiecesbytthecopracutter(notinpicture)isfedintotheoilexpellerontheleft
ofthephoto. Theprefilteredcoconutoil(drumontheleft)ispumpedbyanelectricaldriven
pump(betweendrumandfilter)andpushedthroughaflowlinebagfilter(ontheright). The
hoseatthebottomrightisconnectedtothecoconutoilmaintankofthegenerator.
Photo 13 Coconut Oil production equipment at Welangi
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Source: GillesVaitilingom
Photo 14 45kVAdieselgensetatWelagi
Source:GillesVaitilingom
VanuaBalavu
TheLomalomaCopraBiofuelProjectwascommissionedinApril2000. The90kVALomaloma
CopraBiofuelProjectservesthreevillages(Naqara,SawanaandLomaloma).Sincethisisthe
administrativeheartofVanuaBalavu,electricityisalsosuppliedtotwogovernmentschools,
theLomalomaHospitalandthePostOfficealongwith200customers.
AnElectricityCommitteeformedbythethreevillagesandotherconsumersintheprojects
overseestheprojectmanagement.Apowerhouseoperatorandhisassistantarebeingpaidto
maintainthegeneratorwhileameterreaderhasthetaskofbillingconsumersthrough
readingsofindividualkWhmetersandanotherpersoncollectsthesebills.Thusfourvillagers
areemployedbytheElectricityCommitteeandtheirwagesarepaidthroughthebillscollected
monthly.
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ThecoconutoilmillonVanuaBalavucloseddownshortlybeforethisprojectwas
commissionedandallcopraproducedwassentoutsidetheislandforprocessing. Leftover
coconutoilfromtheoilmilllastedabout8monthsafterwhichoilforthegensetwas
purchasedfromtheSavusavuoilmillonVanuaLevu.
Photo 15 The90kVAdieselgensetatVanuabalavu
Source:GillesVaitilingom
InMarch2005the90kVAcommunitygensetfacedseriousmechanicalproblemsandwas
shutdown. SubsequentlythisgensetwassenttoSuvaforrepairsbutnothingwasdoneabout
itforseveralyears. ItwasrustingawayattheWaluBayworkshoptill2008whentheBiofuel
AdvisorattheDeptofEnergy,KrishnaRaghavan,arrangedfortheFrenchengineerGillesVaitilingomtocometoFijiandhelprepairthisgenset. SincethisisheavydutyDeutzindirect
injectiongensetitcanbeoperatedatevenlowloadsoncoconutoil. Sotheoperating
procedurewaschangedtoamuchsimpler,manualoperationwithonlyonefueltank
containingcoconutoil. Theheatersbelowthefueltanktomeltcoconutoilinwintercanstill
beusedifrequiredbymanuallyoperatinganonoffswitch. Meanwhilethethreevillageson
VanuaBalavuhavegottheirownseparategensets,sotherepaired90kVAcoconutoilgenset
willbeinstalledatanotherlocationwherecoconutoilisavailable.
A SOPAC study team visited the two sites in 2005 to evaluate these two projects for the Fiji
DepartmentofEnergy. Theirconclusionsaregivenbelow:
Thebiofuel
projects
in
Taveuni
and
Vanuabalavu
have
successfully
demonstrated
the
technicalpossibilitytousecoconutoilasafuelforruralelectrification.Theyhavehowever
notresultedintheexpectedsocioeconomicdevelopmentasanticipated.
Provisionofreliableandaffordableelectricityservicestotheremotecommunitiesof
TaveuniandVanuabalavuisahighlyvaluedservicetoimprovestandardofliving.
Dieselhasbeenfoundthemostappropriateandlowestcostfueloptionfortheprovisionof
electricityatbothsitesresearched.
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Eventhoughthoroughfeasibilitystudiesontechnology,socioeconomicsandhavebeen
carriedoutbeforetheimplementationoftheprojects,theexpectationsofthevillagersand
theresultsoftheprojectshavenotbeeninlinewitheachother.
IftheautomaticfuelswitchontheTaveunigeneratorisrepaired,thevillagershavethe
optiononwhethertouse(commerciallyproduced)coconutoilordieselasfuel.For
Vanuabalavutoutilisecoconutoilasafuel,anoilmillwouldhavetobeboughtandoil
millingorganisedasitdoesnotappeartobeeconomicallyattractivetoimportcoconutoil
fromotherislands.
TheevaluationfindingsandsocialsurveyconductedbyPCDFclearlyoutlinesthesocial
constraintsandnoncooperativenessbetweenthe3villagesparticularly,thatofLomaloma
andSawana.Theideaofhavinganelectricitycommitteecomprisingofmembersfromthe
3villagesisnotpractical.Thus,itisunlikelythatacommongeneratorforthevillagesis
suitable.
Thecurrenttariffstructureisnotsustainableasrealcostsareneithercovered,nor
equitablebecauseallhouseholdspaythesameamountirrespectiveoftheirusage.
Generally,newtechnologycansurviveandoperateasdesignedprovideditisused
accordingto
its
specifications.
The
absence
of
technology
in
acommunity
will
only
hinder
(wo)menseffortstodevelopsocially,economicallyandsustainably;
(SOPAC,2006)
Fijiscoconutindustryrevivalprogram
Fijiscoconutindustryhasbeendecliningoverthelast40yearsbecauseoflowproductivity,
lowpricesandcompetitionfromotheredibleoilssoldontheworldmarket. Althoughthere
havebeensomeeffortsinthelastfourdecadestorevivetheindustry,thelackofasustained
longtermnationalpolicyfordevelopmentofthecoconutsectorhasmadeitdifficultto
reversethedecline. Intheearly1960scopraproductionwasover40,000tons/yr;nowitis
lessthan15,000tons/yr.Moreover,abouttwothirdsofthetreeswillgooutofproduction
overthenext20years. Theoldertreesneedtobereplacedsoonotherwisetheindustrywill
declinefurtherandtheruralpeopledependentontheindustrywillmigratetourbanareas
lookingforalternativelivelihoodsaddingmorepressureonthelimitedresourcesoftheurban
centers. Inresponsetothisproblem,theFijianGovernmentcreatedtheCoconutIndustry
DevelopmentAuthority(CIDA)underanActofparliamentinNovember1998,withamandate
torevitalizetheindustry. However,CIDAhasnotbeenabletotakeovertheentire
administrationoftheindustryfromtheMinistryofAgriculturebecauseofthelackof
budgetarysupport. From2005onwards,theGovernmenthasagreedtohandovertoCIDAthe
fullresponsibilitytoadministerallaspectsoftheindustrywithadequatefundingtoenable
CIDAtoperformitsfullroleasrequiredundertheAct.
CIDAhasdrawnupa25yearCoconutIndustryMasterDevelopmentPlanthatincludesa
NationwideCoconutIndustryPromotionsProgram(NCIPP). CIDAaimstorestructurethe
coconutindustry,register20,000coconutgrowersandestablishanetworkofCoconutPlanters
Associationsthroughoutthecoconutgrowingareas. ThiswillassisttheExtensionand
Research&DevelopmentDivisionstoachievetheirtargetsfortheplantingof6milliontrees
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andtherehabilitationofanother2milliontrees. TheTaveuniCoconutCenterwithitsfour
seedgardenswillbeprovidedfinancial,manpowerandlogisticalsupporttoplayakeyrolein
thiscampaign. Amanpowerdevelopmentplanandraisingofpublicawarenessthrough
postersinschools,restaurants,hotels,publicmarketsandgovernmentoffices,etc.arealso
beingplanned.
CIDAaimstoincreasetheproductionofcoprato50,000tons/yr,ofcoconutoilto24,000tons
/yrandoftendernutsforthelocalandexportmarketto40millionnuts/yr. Product
diversification,intercroppingpractices,wholenutpurchasecentersandacentralizedcopra
dryingfacilityareenvisagedtogetherwithalargenumberofminimillsandtwobigcoconutoil
(CNO)mills. CIDAwantstoimprovethelifestyleof100,000ruralpeopleinvolvedinthe
coconutsector,empowerwomen,reducepovertyandimprovetheeducationofruralchildren.
Otherambitioustarget