Briquettes produced from the mixture of agro-industrial residues composed of eucalyptus sawdust with turnip or corn cob cake

Abstract

The generation of waste and/or by-products in the agro-industrial sector is inevitable and, depending on the situation, it can lead to inadequate disposal. The aim of this study was to evaluate the physical properties and the energetic viability of agro-industrial residues composed of the mixture of eucalyptus sawdust with turnip or corn cob cake. The experiment was set up in a completely randomized design with eight treatments, resulting from the mixture of eucalyptus sawdust with turnip/corn cob cake. Pure residues were characterized by immediate analysis, calorific value and thermogravimetric analysis. For briquettes, immediate analysis; apparent and energetic density; diametrical compression resistance, HCV, LCV and thermogravimetric analysis were carried out. For statistical analyses, the Tukey's test was applied in qualitative analyses and regression was used in quantitative analyses with the Sisvar statistical software. The volatile material content decreases as forage turnip cake is added; the composition of 50% of forage turnip cake and 50% of eucalyptus (TN50) presented 76.38% of it, while composition containing 15% of cake, 79.87%. The ash content increased from 3.25% (TN15) to 6.27% (TN50). Both HCV and LCVdecreased with the addition of turnip cake from 17.73% (TN15) to 16.96% (TN50) for HCV and from 16.38% (TN15) to 15.64% (TN50) for LCV. In thermograms, the temperature at which peaks appear is similar among the different mixtures. In the resistance test, the addition of forage turnip cake significantly influenced the addition of residues, increasing from 0.76 MPa (TN15) to 1.52 MPa (TN50). Considering the analyses carried out, and comparing them with results in literature, it is possible to verify that both, briquettes produced from forage turnip cake and those made from corn cob, have energy potential.