Abstract
African balsam (Daniella oliveri) leaves and cow dung are waste materials that are commonly accessible in Africa and can be used to produce biochar by simultaneous thermochemical processing. In this study, biochar was produced in a retort-heated, non-electrically powered, top-lit updraft reactor using the biomass fuel-powered thermochemical conversion of dried cow dung and African balsam leaves at an average temperature of 320 °C.
The biochar was characterized using Fourier transform infrared spectroscopy (FTIR), energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), differential thermal analysis/thermogravimetric analysis (DTA/TGA), and Brunauer–Emmett–Teller (BET) analyses. After carbonization for 100 min, biochar was obtained from processed mixed leaves/cow dung with a yield of 70%. Fourier transform infrared analysis showed the presence of alkene, hydroxyl, alkyne, alkane, and sulfur-containing functional groups.
Scanning electron micrographs showed that the biochar’s surface was made up of fibrillated particles with very few pores. The biochar was observed to have a surface area of 328.199 m2/g with a higher pore volume and lower pore size than biochar produced from cow dung alone. Energy dispersive spectroscopy showed that the biochar is mostly made up of carbon (67%), and that the introduction of the leaves into the biochar feedstock increased its carbon, silicon, potassium, and bromine content.
Differential thermal analysis/thermogravimetric analyses revealed the biochar to be thermally stable. The findings of this study are helpful for attempts to manage solid wastes (African balsam leaves and cow dung), reduce environmental pollution, and produce biochar whose properties are adequate for it to be used as a soil additive. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd.