Valorization of waste cassava peel into biochar: An alternative to electrically-powered process

Abstract

Cassava production and consumption in its raw or processed form have experienced a rise in recent times globally, with Nigeria being the major producer of cassava in the world. However, the increased consumption of this crop has resulted in an increase in its peels, which if not properly disposed of or recycled, would burden the environment. Previous studies have only been able to engage electrically-powered reactors for the thermochemical conversion of these peels, which is a challenge as these reactors cannot be used in regions with an insufficient supply of electricity. In this study, the authors utilized a top-lit updraft reactor with retort heating for the conversion of waste cassava peels into biochar. The reactor, which is relatively cheap, simple to use, and environmentally friendly and modified for biochar production, is biomass-powered. The carbonization process, which lasted for 160 min, obtained a peak reactor temperature of 338 ℃, and gave rise to a biochar yield of 55.13 %. FTIR analysis revealed that the cassava peel biochar consists of similar functional groups in relation to its precursor, but consists of more oxygenated functional groups. The BET surface area and BJH pore diameter of the biochar were obtained to be 319.784 m²/g and 2.447 nm, respectively. EDX analysis showed the biochar is majorly made up of carbon (56.93 %) and silver (22.97 %). SEM micrographs revealed that the biochar has a rough and porous surface. The DTA/TGA results showed that the carbonization process improved the thermal efficiency of the cassava peel material.