Análise do potencial sinergético entre carvão e biomassa na produção de gás combustível por Copirólise

Abstract

Global energy production presents major challenges, one of which is the efficient use of available raw materials, such as coal and biomass. Biomass has been gaining space in the global energy matrix due to its renewable factor, in contrast to coal. New biomasses are studied every year in order to promote their use in the global scenario, and one of these biomasses is the annoni grass, an invasive grass without wide commercial application. One of the available methods for energy production is copirolysis, a thermal degradation process without the presence of oxygen, in which two or more raw materials interact with each other to form products with high energy potential. In this process, the operating parameters directly influence the yield and composition of the products. From this, this study seeks to optimize the copyrolisis process of annoni grass with mineral coal for fuel gas production, using computational tools for the interactive analysis of the parameters. For this, a design of experiment Central Composite, 22/4 factorial, was proposed, with the analysis factors being: temperature, in the ranges of 300 °C, 380 °C and 460 °C, and mass ratio of grass/charcoal, in the ranges of 0.17, 0.5 and 0.83. Copyrolysis tests were carried out in a fixed bed batch reactor and the products analyzed by gas chromatography. From the experiments, several responses were produced, being analyzed the production of volatiles, H2, CH4 and conversion to gas. An increase in gas production between 12% and 15% was observed in the region of 30% in mass of grass for coal. For the production of H2 there was an increase between 1% and 3%, being considered a low value and of low relevance, since this production range is within the error of the statistical analysis, a similar effect occurred with the production of CH4, in which there was an initial decrease in production, stabilizing its observed production with the theoretical one as the temperature increased. Despite this, it was possible to observe that, in both responses, there was a better production of the product between the ranges of 20% and 40% of grass for charcoal. According to these results, an optimized process value was obtained, so that the greatest conversion of the products to gas occurs. In this way, the process parameters were estimated at a mass ratio of grass/coal of 0.3, at the temperature of 440°C, obtaining a feed mass conversion of 26.3%, with an increase in gas production of 11.3%. Thus, capim-annoni and coal presented themselves as good raw materials for the generation of fuel gases in the southern region of the country, evidencing capim-annoni as a product of relevance and interest for possible application in economic development on the region.