Biogas synthesis from Human Excreta using Zirconia Doped Silica Catalyst

Abstract

Open defecation is an enormous environmental hazard that plaques the ecosystem. A laboratory scale batch biogas digestion using human excreta was undertaken with zirconia doped silica catalyst (ZrO2/SiO2). The mass of gas produced, methane content were measured by electronic weighing balance and Mestek CGAO2A methane detector respectively. The effect of catalyst doping and catalyst loading on yield were studied. The catalyst increased the yield of biogas from 7.22L/Kg/VS (Litres per kilogram volatile solid) to 19.02L/KgVS and methane content from 14.00% LEL. This equals the purity level of externally purified biogas and meets the energy (Calorie value) need for domestic and industrial applications. This result of the biogas yield shows a remarkable 163.90% efficiency in yield of catalyzed digestion over uncataylzed and 592.80% increase in methane content over the un-catalyzed system using the same substrate