Análise técnico-econômica para a implantação de uma usina de biometano com injeção na rede de gás natural

Abstract

This dissertation presents a study of technical and economic feasibility, for the implantation of biomethane gas generating plants, from the purification of biogas generated from the anaerobic biodigestion of biomass from agro-industrial residues. The biomethane produced can be used for vehicular use at the production site or injected into the natural gas network. The work describes an economic analysis, based on model plants, which contemplates the investments required for construction and the expected financial return in realistic contexts. To this end, the relevant technical factors for the production of biogas are identified, and exemplified by means of model plants, in order to evaluate promising projects that use the energy potential of biomethane. Results suggest the economic viability of the model plants studied, but with a time of financial return, of the investment, over ten years in the worst cases studied (scenario 3). In the most favorable scenario (scenario 4), the plant would achieve a financial return in less than two years. In the study it was found that, for a model plant to be viable (scenario 3 and scenario 4), it must seek extra revenue from the sale of biofertilizers and carbon dioxide, for example. In addition, it appears that the specific price of biomethane gas generated, in the worst scenarios (scenarios 1.2 and 3), may be 166% higher than the value of natural gas. The lowest price obtained for biomethane gas (scenario 4) was approximately 1.8% lower than the price of piped natural gas. Therefore, this work demonstrates that the implantation of a biomethane plant, in the state of Rio Grande do Sul, can be technically and economically viable, since the by-products are also commercialized.