Estimación del Potencial Eléctrico del Biogás Obtenido de Biomasa Residual Bovina y Porcina en ZNI de Colombia

Abstract

This research presents an integrated point of view about the full process of biogas production, starting from livestock waste and its transformation to electricity. Also, it looks for the general way to stimate the maximum potential of the waste (Pr), the usable theoretical potential (Pteo) and the technical potential (Ptec) of biogas produced by the anaerobic digestion of bovine and porcine biomass waste. The analysis was mainly oriented to non-interconnected zones (ZNI) where the waste availability and the electricity supply needs force to find energetic alternatives. Biogas production is estimated using the Anaerobic Digestion Model No 1 (ADM1). While the energy potentials are calculated taking into account the operational parameters of the technologies involved in the biogas-electricity conversion process. These conversion technologies include fuel cells (CC), gas turbines (TG) and internal combustion engines (MCI), which are analyzed from a review of the literature and the application of different mathematical models. All models were implemented and integrated in a simulation environment developed in MATLAB/Simulink® that facilitate and expedite its use. Additionally, a methodology is formulated to estimate the Pr, the Pteo and the Ptec. At the same time, it identify the ZNI of Colombia where the power generation systems from biogas (SGEB) have better perspectives for its implementation. This methodology is also able to determine the amount of waste needed to supply a specific electrical demand. In order to present the functionality of the proposed methodology and the implemented models, two possible scenarios of application in the ZNI were simulated, one for anaerobic digestion of cattle slurry and the other for the swine manure. The maximum biogas potential generated by the anaerobic digestion of 100% of bovine and porcine biomass waste of all the ZNI is over to 32000 and 600 GJ/day, respectively. At the same time, the estimated theoretical potential, taking into account a residual biomass recovery factor of 12,5%, is around 3800 GJ / day for cattle slurry and 81 GJ/day for swine manure. Meanwhile, to determine the electrical potential, 40, 30 and 50% biogas-electricity conversion efficiencies were considered in conversion modules based on MCI, TG and CC, respectively. For the technology with the lowest efficiency (TG) the technical potential was 320,83 MWh/day for the bovine industry and 6,83 MWh/day for the swine industry. Assuming an average consumption per user of 5,06 kWh, cattle slurry from all the ZNI could supply 63400 households and 1348 households with swine manure.