Potencial energético do esterco bovino em Alagoas: valor de substituição e impacto da biodigestão anaeróbia.

Abstract

Manure production has already proved to be an effective fertilizer source, as well as reducing the use of chemical fertilizers, which contribute to the increase of soil acidity. Among the organic fertilizers, cattle manure is the most used and one of the most produced in the Northeast of the country, especially the Alagoas milk basin, which produces an average of 40,000 L of milk per day and has about 1,264,053 heads bovine animals in the state of Alagoas (IBGE, 2016), with a total of 192,181 milked cows, considering the animals on December 31 of that year. In view of the potential for manure production generated by dairy cattle in the state of Alagoas, the objective of this study was to conduct a bibliographical research through literature review in the sources: information sites of state and federal agencies and local magazines that address the theme and the from it, to present an alternative of sustainable energy production for Alagoas. For that, the macronutrients of cattle manure and biogas obtained through anaerobic biodigestion and the replacement of the chemical fertilizer by the biofertilizer were quantified in energy value. Considering the Alagoas dairy herd of 2016, the study showed that the State has an average production potential of 4,035,801 kg / day of manure, being able to generate 21,389.75 kg / day of Nitrogen, 8,475.18 kg / day of Phosphorus and 17,353.94 Kg / day of Potassium, being able to reach a production of 161,432.04 m³ / day of biogas with an energetic value of 2,620,849,169.40 KJ / Kg and generating an availability of 230,847,8172 kWh of electric energy per day, what would give to supply 43,284 residences monthly in the State of Alagoas. When considering the substitution of the chemical fertilizer by the biofertilizer, a saving of fossil energy in the order of 612,865,106.15 MJ / year was obtained.