Pirólise de resíduos da cultura de pimenta-do-reino capixaba: atividade experimental problematizada (AEP)

Abstract

This dissertation investigates the use of black pepper crop residues as promising lignocellulosic biomass, focusing on its physicochemical characteristics, energy potential and didactic application in the teaching of Chemistry. The biomass had a majority composition of carbon and oxygen (above 90%), in addition to 9.38% moisture, 79.43% volatiles, 11.18% ash and 9.39% fixed carbon. Pyrolysis was performed for bio-oil production, and the best yield (51.53%) was obtained at 550 °C, with a heating rate of 20 °C min⁻¹ and an N₂ flow of 100 mL min⁻¹. The bio-oils were chemically characterized, identifying compounds such as carboxylic acids, ketones and hydrocarbons, with potential energy and biotechnological application. The kinetic study, based on the Flynn–Ozawa–Wall, Kissinger–Akahira–Sunose and Friedman isoconversion models, indicated mean activation energies between 161–163 kJ mol⁻¹ and high thermal dependence; The use of catalyst did not significantly alter the kinetic patterns. In the field of teaching, the didactic intervention revealed advances in the understanding of the concepts of Chemical Kinetics, especially in the quantitative aspects. Indicators of metacognitive development showed gains in analytical (5.38–5.76), practical (4.68–5.28), and creative (5.06–5.53) capacities. The Grounded Theory revealed that factors such as the contextualization in sustainability, the availability of basic equipment and student engagement were determinant for the success of the proposal, although challenges such as lack of advanced equipment and reduced time for deepening were identified. The results show the potential of integration between science and education, promoting connections between academic knowledge and socio-environmental issues, and contributing to the training of critical professionals committed to sustainability