Caracterização e secagem do bagaço de malte

Abstract

Brewer’s spent grain, generated as a byproduct of the brewing industry, represents a potential raw material for renewable energy generation. This study aims to investigate the physical, chemical and flowability characteristics of biomass for industrial processing, as well as the drying of the residue. The bagasse sample was obtained from a local brewery and dried to 8-10% moisture content for proper storage. Physical analysis showed that the mean Sauter diameter was 1,92 mm and the RRB model best fitted the size distribution data. The true density was 1327,8 ± 3,7 kg m−3, and it was observed that the particle diameter did not significantly influence its density. Four shapes were identified in the bagasse sample, named BSG1, BSG2, BSG3 and BSG4, with the BSG4 type representing 54% of the total mass. Furthermore, the study of shape and morphology showed the irregularity and heterogeneity of the biomass sample. Through flowability tests, 𝐻𝑅, 𝐶𝐶𝐼 and AOR were determined, whose values were 1,15±0,01%, 13,00±0,58% and 42,9±0,4°, respectively. The characterization of flowability indicated that the material has excellent fluidity, indicating little cohesion between particles. Furthermore, the drag and permeability coefficients were close to the values obtained in the literature for other biomasses. The compositional analysis of the brewer’s spent grain showed that the biomass has 15,99±2,33% extractives, 22,61±1,14% lignin, 18,63±0,59% cellulose, 18,90±2,35% hemicellulose, and 4,03±0,03% total ash. Drying was carried out in a tunnel dryer at drying air temperatures of 40 °C, 45 °C and 50 °C, and the results showed that moisture diffusivity increased with increasing temperature, and that thermodiffusion was negligible. This study highlights the potential of brewer’s spent grain for industrial applications due to its significant availability, low cost and chemical composition.