Q-211. Biogas Production as a New Trend of Alternative Energy in Brazilian Great Cities

L. C. M. das Neves, C. F. M. Souza, M. Ishii, T. C. V. Penna;
Univ. of São Paulo, São Paulo, BRAZIL.

Energy has been the base of human society since the more remote civilizations. Actually, energetic sources are each more necessary to promote the economic, social and cultural development. Alternative energy sources (wind, solar, biofuels) show capability to minimize the exhaustion and environmental problems of traditional energy sources. Industrialized and urbanized regions show a great environmental problem with the generation of organic residues. Anaerobic microorganism cultivations can degrade pollutants resulting in two kinds of by-products: activated sludge and biogas. The correct management of residual waste presents highest costs and the non-adequate treatment and destination can compromise this treatment. Environmental agencies have been stimulating the use of treated residual waste as fertilizer since removed pathogenic agents and reducing the humidity levels. Biogas can be utilized as an alternative energy source, basically formed by methane and hydrogen. Full-scale applications of anaerobic wastewater treatment technology have become widely accepted in the last decades due to the successfully development of several high-rate reactors. Great cities in development countries show the potential energy generation of 20 MW from the utilization of 50 m3/s of urban residue. Moreover, hydrogen production rate of 13.0 L/L.d (liters of hydrogen by liters of media per day) in a continuous reactor was attained when utilizing Bacillus subtilis in several plants. This work aims to evaluate the capability of production and application of biogas as alternative energy sources produced in urbanized areas by Bacillus subtilis cultivations and to compare the viability with other knowledge energy sources (oil, hydroelectricity, thermoelectricity, nuclear, wind and solar energies).