Biodigestão anaeróbia dos resíduos orgânicos do restaurante universitário da UNIPAMPA – Campus Bagé

Abstract

The usage of the different types of biomass is one of the alternatives for the generation of energy, not only for the economic advantages deriving from its use, but also for the environmental advantages. As an alternative to this panorama, one has the biogas. Biogas is a gas mixture rich in methane and carbon dioxide, produced naturally in anaerobic environment by the action of bacteria on organic matter that are fermented within certain limits of temperature, moisture content and acidity. In this research, laboratory production of biogas was studied, with organic solid residues from the university restaurant of the Universidade Federal do Pampa, campus Bagé. The biogas can be converted into thermal or electric energy, by means of the oxidation of methane to supply part of the demand of said University Restaurant. The amount of methane in the biogas was not chemically determined. However, through the flame test, the gas has burned, indicating that it was combustible. In such work, 0.076 m3 of biogas per kg of waste was produced. The average generation of food waste from the restaurant is 1,714 kg month-1, which makes it possible to produce up to 1,522 m3 month-1 of biogas equivalent to 2,283 m3 month-1 of liquefied petroleum gas (1: 1,5). In this way, biogas can supply 95.15% of the restaurant gas demand (2.4 m3 month-1). Reducing carbon dioxide emissions. Based on these results, it was proposed the construction of a Canadian model bio-digester in the University, because, in addition to the lower cost of installation, it would have better use of solar radiation, since the region has low temperatures for most of the year. Calculations of financial return were made with the option of using commercial bio-digesters. A system was also proposed for a greater number of biogas withdrawals, since it was simulated that the accumulation of gases inside the digester would hinder the growth of the bacterial population, thus reducing the production and quality of the biogas.