Análise do potencial energético de briquetes “in natura” e carbonizados de capim super napier

Abstract

The growing demand for alternative energy sources and the need to mitigate the environmental impacts resulting from the intensive use of fossil fuels have driven the search for renewable and sustainable sources of energy. Biomass stands out as one of the most promising alternatives due to its large-scale availability, renewability, and potential to reduce greenhouse gas emissions. Although there are several studies on the use of biomass for energy production, specific literature regarding super napier grass (S.N.G.) and its application in the form of briquettes is still relatively scarce. In this context, the present study aims to analyze the energy potential of raw and carbonized super napier grass briquettes. To achieve this goal, samples were prepared, and their physical, chemical, and thermal characteristics were determined; raw and carbonized S.N.G. briquettes were produced and characterized.The carbonization of the S.N.G. sample was carried out at a temperature of 400°C with a residence time of 3 hours. Briquettes were produced with a moisture content of 10.58%, particle size smaller than 0.9 mm, a pressure of 10 MPa, and a temperature of 120°C. To produce carbonized briquettes, a binder (raw S.N.G.) was used. It was found that a 40% mass proportion of raw S.N.G. was sufficient to bind the carbonized particles without causing significant mass loss in the briquettes.The raw and carbonized briquettes showed satisfactory energy conditions, similar to charcoal and superior to those of mafurreira firewood. It is worth noting that the raw S.N.G. briquettes had a high yield (24.98%) in the water boiling test compared to carbonized briquettes, charcoal, and mafurreira firewood. Therefore, for systems that require quick and efficient heat (such as stoves and wood-fired ovens), it is more practical to use raw S.N.G. briquettes, while for systems that require a constant and prolonged heat flow (such as industrial boilers and residential heating systems), it is more practical to use carbonized briquettes. Consequently, the analysis of other types of binders and the performance of emissions testing were recommended.