Determinación del potencial energético para la obtención de biogás, a partir de la co-digestión anaerobia del co-sustrato cascarilla de arroz con excretas porcinas

Abstract

The implementation of alternative energies, are of great importance with respect to the growing generation of waste from the agricultural sector in the department of Meta. The use of this kind of wastes, generated by various productive sectors of the country, can impact positively in the environment. Due to that, the present study determined the feasibility of using rice husk in co-digestion with swine manure for the production of biogas, taking advantage of the energy potential of this substrate. A physical and chemical characterization of the rice husk (produced in the Meta Region) was achieved as first step of the investigation. This substrate was constituted with 81,70% ST and 79.80% SV, data with a standardized deviation of 3,4 – 4,4 respectively and consumable carbon availability of 3,913.48mg/l, associated with the nature of the substrate, which contains carbohydrates, proteins and lipids; This allowed us to consider an initial notion of the energy potential to subsequently carry out an analysis based on the volume of biogas, and it was possible to establish that the factors of greatest influence in this process were: pH, time of digestion and inoculum quality, nature of the co-substrate and high levels of nitrogen.

The feasibility of biogas production of the substrate in co-digestionwas carried out taking into account the parameters described in the APHA (Standard Methods) for solid fractions. The process, maintained mesophilic temperature conditions, of 37˚C, implementing the process of anaerobic co-digestion, by means of an experimental assembly, using 6 biodigesters, which were analyzed in 4 runs of 15 days each, varying in them the amount of co-substrate (rice husk) analyzed; prior to the runs of analysis, a pilot test was carried out in which the characteristics to be modified in the subsequent assemblies were identified. Daily monitoring of the volume of Biogas obtained in each biodigester was made, and environmental variables such as temperature, relative humidity and pressure were measured daily.The allowed establishing that the energy potential of the rice husk co-substrate with optimal pig excreta was 20,81ml/grSV and an average CH4 percentage of 50,6% being feasible for the implementation of rural biodigesters as an alternative energy method and possible solution to the energy deficit.