Aproveitamento energético do biogás gerado pela digestão anaerobia da biomassa proveniente de uma cervejaria artesanal

Abstract

The beer industry has increasingly shown its potential, growing more and more and standing out on the world scene. This fact brings an environmental concern associated with high waste generation, with beer spent grain (BSG) being the major part among them. Anaerobic digestion appears as an option not only for the treatment of this waste, but also to produce biogas, which is characterized by being a renewable and clean energy, with several applications, one of which 1s to be used by the industry itself. In this way, this work intends to analyze anaerobic digestion as a way to add value to the BSG of a craft brewery through the energetic use of the biogas produced. To obtain the results, the bagasse mass produced in one year was quantified, presenting a daily average of 94.77 kg.day-1 for the two most representative labels in terms of beer production volume. Using literature data on methanogenic production in anaerobic digestion of BSG, the biogas production estimative of the brewery was 5.99 m3 of CH4.day-1. For energy use, it has been calculated the generation of electric energy considering gas engines, gas turbines and gas microturbines as conversion technologies, which could reach 438.53 kWh.month-1. Therefore, BSG can be used to partially supply the electricity demand in the craft brewery and can also be used as fuel for the boiler responsible for the heating of the water used in the wort preparation.