Composition analysis of biomass for biofuels

Sep 2014

Composition analysis of biomass for biofuelsIntroduction• Compositionofbiomassfeedstocksishighlyvariable.

• Highthroughputandaccuratecharacterizationofbiomassfeedstocksisanecessityforanybiomass-to-biofuelsconversionprogramasitenablesevaluationofconversionyieldsandprocesseconomics

• Biomassmainlyconsistsofcellulose,hemicellulose,ligninandash.Biomasscarbohydratecontentisofprimeimportancebecauseitisdirectlyproportionaltoethanolyield.

• Fibrethermusesfiltrationmethodtodeterminecrudefibre,neutraldetergentfibre(NDF)andaciddetergentfibre(ADF).Itoptimizesthedigestionofthesamplesandspeedsupthewashingandfiltrationprocesses.Hence,morenumberofsamplescanbehandledinarelativelyshorttime.

• Calorificvalue(CV)istheamountofheatproducedbythecompletecombustionofamaterialandisexpressedinKcal/Kg.Higherthecalorificvalueofthebiomassthebetterisit’ssuitabilityforpowergeneration.

Methodology• Moisture(%):1gofdrybiomasssampleistakenandmoisture

percentageiscalculatedusingmoisturebalance.

• NDF(%):1gofmoisturefreesampleistakenandplacedinafibrebagalongwiththespacerwithNDFsolutioninfibretherm.NDFtreatedsampleiswashed,driedovernightandweightstaken.

• ADF(%):ThedriedsampleisrunwithADFsolution.ADFtreatedsampleiswashed,driedovernightandweightstaken.

• Aciddetergentlignin(ADL)(%):ThedriedsamplesaretransferredtoGoochcruciblesandtreatedwith72%H

2SO

4for3hours.The

cruciblesarewashed,driedovernightandweightstaken.

• Ash(%):Thecruciblesareplacedinmufflefurnaceat500°Cfor4hoursandweightstakenaftercooling.

• CV(Kcal/Kg):Sampleisweighedandplacedinaheavydutystainlesssteelcylinderreferredas“Bomb”whichissealedwithoxygenandthesampleisignitedelectrically.Thecompleteoxidationofthecompoundreleasesheatandismeasuredthroughthetemperatureriseofthewaterbyasensor,whichisusedtocalculatecalorificvalue.

Formulae• NDF=((Dryweightofsampleaftertreatment-Ash)/Initialweight

ofthesample)*100

• ADF=((Dryweightofsampleaftertreatment-Ash)/Initialweightofthesample)*100

• ADL=((Dryweightofsampleafter72%H2SO

4treatment-Ash)/

Initialweightofthesample)*100

• Hemicellulose=((NDF–ADF)/weightofsample)*100

• Cellulose=((ADF–ADL)/weightofsample)*100

• Silica=((weightofcrucibleafterignition-weightofemptycrucible)/weightofsample)*100

• CV=TxW-(CVT+CVW)/M

• WhereT:riseintemperature(°C);W:waterequivalent(Cal/°C);CVT:CVofthread;CVw:CVofignitionwire;M:massofsample(g)

Results• Compositionanalysisofdifferenttypesofsorghum

Conclusions• Therangeofcellulose,hemicelluloseandligninamongsorghumtypesishigh.

• Highcalorificvaluefeedstocksarepreferableforbio-powerprojects.

Fibrethermapparatus DigitalBombCalorimeter

For further information please contact: Dr P. Srinivasa Rao, Senior Scientist, Research Program – Dryland Cereals. Email: p.srinivasarao@cgiar.org

Thisworkisbeingundertakenaspartofthe

Cellulose

HemicelluloseLignin

Ash

Moisture

ICSV93046

ICSV25333

KansasCollier-bmr6

SSG59-3 CO19

RTx430-bmr12

ICSSH71

ICSSH28

DBT