Sustainable Recycling of Waste Epoxy, Biomass and Its Blends as Alternative Reductants for Hematite Using Microwave Technology

The circular economy demands that products are reused, recycled or reproduced into another product for a sustainable environment. The rising amount of greenhouse gases in the atmosphere calls for clean fuels to be used in production. Biomass is known to contain a considerable amount of carbon likewise, epoxy which is a thermosetting plastic. Laboratory studies on the use of waste epoxy, bamboo and coconut shells (CNS) as reductants were performed on reagent grade ferric oxide (96.89 wt. % Fe2O3) using a domestic microwave oven of 1400 W power rating. Composite pellets of 30% and 70% were formed from the mixtures of ferric oxide and carbonaceous materials respectively. The composite pellets were fired in a microwave oven for 30 minutes. The percent mass loss and extent of reduction were then calculated after firing. The results depict that metallic iron can be produced effectively using epoxy, bamboo, CNS and their blends as reducing agents. Analysis of the results indicates a blend of 35 % Bamboo, 35 % CNS and 30 % epoxy attained the highest reduction of 95.41 %, which was closely followed by a blend 30 % epoxy and 70 % CNS of 92.92 %. The individual carbonaceous materials also recorded significant reduction of 74.76 %, 78.22 % and 83.65 % for bamboo, CNS, and epoxy respectively. From the laboratory results obtained, waste epoxy, coconut shells and bamboo can be recycled in an eco-friendly and sustainable manner through their usage as an alternative reductant for ferric oxide. Also, the success achieved with reduction in the microwave environment can catalyse the gradual shift from the conventional blast furnace used in iron production.