Anaerobic digestion of ethanol distillery waste-stillage for biogas production

Dependence on oil imported from foreign countries affect the National Energy securitiesand Energy security of global economies has become one of the most challenging problemthat needs to be resolved as the fossil sources are fast diminishing and irreplaceable. Thealarming energy demand and consumption rate of the present global status is currentlyexponentially exceeding the rate of local supply sources, becoming an issue of concern. Alook beyond the fossils is crucial for long tern economic growth and energy security asthere are numerous uncertainties about the fossil supplies coupled with the greaterenvironmental risks encountered during exploitation. Thus the new concept for treatingethanol distillery waste anaerobically to produce Biogas- a clean renewable alternativeenergy with many applications projects sustainable and more realistic option.The research project focuses on Comparison of the Potentials and Efficacy of AnaerobicDigestion of Stillage (Wheat Stillage and Lignocellulose Stillage) from Ethanol Distilleryplants for Biogas Production. It also investigates better alternative temperature dependentStillage Anaerobic Digestion that will enhance a higher Biogas yield.Anaerobic digestions were performed in triplicate batch systems, during both mesophilic(35 °C) and thermophilic (55 °C) conditions at a period of 50-days. The reactors contained2.73g of Wheat Stillage and 5.2g of Lignocellulose Stillage samples, respectively,corresponding to 2% VS in each reactor. The inoculum was taken from either a mesophilicBiogas Plant (Gässlosa., Borås), or from a thermophilic Biogas Plant (Sobacken, Borås). AGas Chromatographic method (GC) was employed for determination of the obtained biogascomposition.The theoretical CH4 Potential for Wheat Stillage and Lignocellulose Stillage is 0.473m3CH4/kg VS and 0.407 m3CH4/kg VS, respectively. The results obtained from this studyindicated, however, that the Wheat Stillage performed better under thermophilic conditionswith a peak of 575ml CH4 / 0.5g VS; while the Lignocellulosic Stillage gave the bestperformance under mesophilic conditions leading to a methane production of 436ml CH4/0.5g VS after 4 weeks of digestion period.Uppsatsnivå: