ENERGY VALORIZATION OF BIOGAS AND CURRENT ALTERNATIVES FOR ELECTRICITY PRODUCTION

Julian Esteban Barrera¹; Marco Antonio CAsarin¹; Paulo Belli Filho¹; Hugo Gosmann¹; Edson Bazzo¹

¹ Federal University of Santa Catarina

doi:10.20906/CPS/COB-2015-0725

Resumo

Based on the current status of the harnessing and exploitation of the biogas in the state of Santa Catarina, this paper analyzes various strategies for taking full advantage of its energy potential. The MSW (Municipal Solid Waste) and the swine waste appear as the sources with the greatest biogas availability, representing a current production of about 4.2 millions of cubic meters per day. Three currently accessible technologies for electricity generation were compared with the biomethane production and exportation, taking into account the typical compositions for the landfill biogas and the swine waste-derived biogas. Given the different nature and processing level for these options, the analysis was carried out on an exergy basis with the aim of determining the most efficient alternative for the biogas energy valorization in each case. The results indicated the electricity generation as the best choice when compared with biomethane exportation, due mainly by the exergy consumption of the compression stage necessary for gas transportation. Analogously, among the generation alternatives, it was found that biogas engines are the most convenient choice in both cases, mainly because of its low exergy destruction rate when compared with biogas microturbines and steam turbines. By other side, the waste heat exergy coming from the engines can be recovered more easily, enabling the implementation of cogeneration schemes. Scaling these results to the whole state biogas production, it results in the empowerment of about 1.7 GW that were not previously exploited and an annual generation potential of about 4,8 TWh.

Palavras-chave: Biogas; Energy Valorization; Exergy Analysis; Biomethane; Thermodynamic Cycles