Recuperação de energia a partir do tratamento de resíduos de uma indústria cervejeira artesanal

Abstract

The brewery industry has an important role in the Brazilian agroindustrial sector with a positive impact in the country's economy. In the local context, Alagoas has shown a growth in the number of craft breweries and, as a consequence of this expansion, the importance of the study and optimization of beer production waste management grows. These subproducts, characterized by the high content of negative organic load and solids, need appropriate treatment to minimize the negative impact to the ecosystem in which they are inserted. Aiming to offer an alternative to the containment of this impact, was investigated the biomethane energetic potential generated from the waste (fermented yeast, malt bagasse) of a local craft brewery, analyzing different scenarios characterized by the use of different combinations of these different waste: RF (fermented yeast), RB (malt bagasse), RFB (1:2), RFB (1:4,5) e RFB(1:9), with the last three using a mixture of fermented yeast and malt bagasse in different proportions. Based on methanogenic production data, it was estimated the biogas production capacity of the unit, resulting in 9,49 m³ de CH 4 .day -1 , using the RFB (1:4,5) scenario data. To the energetic use, the electric power generated by the biogas was calculated and showed the best performance in the RFB (1:4,5) scenario with the use of gas engines, generating 844,33 kWh/month, being able to supply until 4% of the electric energy consumption required by the brewery. In addition, it was verified that directing the biogas produced in the RFB(1:4,5) scenario to generate thermal energy in the industry boiler could supply 18,7% of the monthly total natural gas required by the brewery. Thus, the study demonstrates that the brewery waste can be used to partially meet its electric energy demand as well as the thermic energy needed for the boiler operation.