Physicochemical properties of pyrolyzed shea kernel and groundnut shells for alternative energy applications

Abstract

This paper presents the results of an experimental and analytical study of the physicochemical properties of pyrolyzed biomass for use as alternative energy sources. Shea kernel shell (SKS) and groundnut shell (GS) are known agricultural wastes and were investigated using the slow pyrolysis technique to assess their energy generation potential. In this study, the KSK and GS were pyrolyzed at heating rate of 10 °C/min at ∼ 400, 500, 600 and 700oC respectively and the products (liquid oil, syngas, and activated char) were collected and characterized for their properties. The values for volatile matter (VM) for SKS and GS were reported to be ∼70% whereas their fixed carbon (FC) values were up to ∼ 41% and up to ∼25.67% respectively. The relatively high volatile matter and fixed carbon compositions signify good fuel potential of both feedstocks. The calorific value of the SKS ranged from 19.54 29.91 MJ/kg and 17.24 - ∼27.88 MJ/kg for GS. The hydrogen-to-carbon (H/C) ratios of ∼0.054 – 0.121 and ∼0.057 – 0.124 and oxygen-to-carbon (O/C) ratios of ∼0.736 – 0.845 and ∼0.663 – 0.754 were obtained for the GS products and SKS respectively indicating that, they possess good combustion properties. The aromatic and aliphatic functional properties were also detected with the activated biochar having higher energy densities, good combustion and chemical properties. The application of the products would enhance environmental sustainability through innovative waste management and by-products recycling. The implications of the results are discussed to demonstrate the scale-up potential of agrowastes as reliable sources of energy

Keywords

• Slow pyrolysis
• biochar
• physical activation
• biomass
• sustainability
• Materials Science