Resíduos madeireiros urbanos como matéria prima para a produção de combustíveis sólidos compactados

Abstract

The use of biomass residues in Brazil has been shown to be a promising alternative for energy generation and impact mitigation. Regarding the reuse of wood residues for energy purposes, those of urban origin stand out, as they are a clean and renewable energy source. However, the use of these residues can be difficult due to the high heterogeneity of these materials and their low energy density. In this context, alternative use for this biomass would be the production of briquettes. Briquetting makes it possible to obtain solid biofuels with greater energy density, making biomass more attractive and usable for energy purposes. The aim of this study was to characterize urban wood waste (RMOU), as well as to analyze the effect of adding eucalyptus shavings to RMOU and also to evaluate the influence of particle size of these raw materials for the production of briquettes for energy purposes. The RMOU were collected at the cashew transfer station belonging to the Municipal Urban Cleaning Company (COMLURB) in the city of Rio de Janeiro, RJ, and eucalyptus wood shavings obtained from a small sawmill located in the city of Jerônimo Monteiro, ES. Data were subjected to analysis of variance and, when significant differences were presented, regression model adjustments were performed. For non-parametric statistics, the Kruskal-Wallis test was used to perform analysis of variance, as these variables did not show normal distribution, even after data transformation. Correlation analyzes were also performed. The results indicate that the RMOU had characteristics that qualify them for energy use. On the other hand, the addition of eucalyptus wood to the RMOU enabled a reduction in the ash content and thermal degradation. Thus, treatment with 50% RMOU and 50% eucalyptus (T3) is the most recommended for energy use. Among the briquettes, the particle size distribution of the raw material had a very similar effect on the compressive strength and density of the product. From a practical and energy point of view, crushing particle sizes below 0.85 mm is probably unnecessary, as if large particles are sieved and used to make briquettes, the milling process can be eliminated and production costs reduced.