Low cost biodigesters for zero grazing smallholder dairy farmers in Tanzania

摘要

ThisreportpresentsthefindingsofaresearchprojectsponsoredbyAfricanDevelopmentFoundation(ADF)nbsp;andcarriedoutinTanga,Muheza,WestandEastUsambarapartsofTanzaniabetweenthemonthsofAugust1994andJanuary1996.Forty-sixbiodigesterswereinstalledinselectedvillages.Thegasproducedwasoflowpressure,ofrightcompositionandsafetouse.Itwasalsoobservedthatdifferencesinattitudeandanimalfeedsinouroperationzonesdidnotsignificantlyaffectgasproductionandcomposition.Thebiodigestersaretoacertainextentfragileandthereisaneedforprotectionagainstperforationandsunlighttoincreasedurability.Thegasproducedifwellusedcouldsaveuptomorethan50%ofcookingenergyneeds.Itwasobservedthat,onaverage,5hoursofnbsp;householdlaborweresavedperdaybecauseofthenbsp;introductionofnbsp;Biogas.Theuseofbiogasalleviatestheworkloadofwomenandmakesitpossibleformentoparticipateinprovidingforenergyneedsathomesteadlevel;arolewhichisotherwisetraditionallywomen's.Itwasestimatedthatthecostofinvestmentcouldberecoveredinaperiodintherangeof9to18months,accordingtotherelativepricesofmaterialsandofcharcoal.Furthermore,theuseoflow-costbiogasreducesthecuttingofhighlyvaluablehardwoodandhenceprotectstheenvironment.