(593j) Effect of Substrate and Temperature On Biogas Production From Anaerobic Digestion

Anaerobic digestion of waste has been shown to be a potential route to produce sustainable energy.  Organic waste is decomposed by anaerobes in the absence of oxygen to produce biogas, a mixture of mainly carbon dioxide and methane, which can be used to generate electricity or run gas powered devices such as refrigerators and lights.  This technology has emerged as an attractive energy source for rural areas without access to electricity due to its simplicity and relatively low cost.  In this work, we have attempted to determine the effect of temperature and substrate type on the bench scale in the hopes of maximizing methane production.  Temperatures within the supposed optimal operating regime (20°C-40°C) are tested, along with a variety of substrates ranging from discarded kitchen waste, to cow mature and dog feces over a period of 2 months.  Concentration measurements of methane, hydrogen, carbon dioxide, nitrogen and oxygen show that the mixture of cow manure and dog feces yields the highest amount of combustible biogas over the time period tested.  Results and suggestions will be used to develop a larger scale household demonstration unit to provide light to a rural township in Johannesburg, South Africa.