The preparation, layered characterization and potential applications of corncob biochar

Abstract

To investigate the characteristics of biochar produced from different parts of corncob, biochar was prepared using corncob as a raw material at constant temperatures of 500 °C, 600 °C, and 700 °C, and the biochar was divided into three parts based on its macroscopic structure: an inner layer (CC-N), a middle layer (CC-Z), and an outer layer (CC-W). The composition and physicochemical changes of the biochar samples were evaluated via FTIR, XRD, Raman, and SEM. The results revealed that the microstructure of corncob is heterogeneous, with CC-N resembling withered leaves, CC-Z resembling blocks, and CC-W resembling sheets. The specific surface area and average pore size of the biochar significantly decreased from the inner layer to the outer layer. The functional group structures of the three parts of the biochar are similar, but the infrared spectrum of CC-N has the greatest peak intensity. The degree of graphitization and thermal stability of CC-N were lower than those of CC-Z and CC-W. Higher-temperature pyrolysis promoted the graphitization of char and improved its thermal stability. This research provides important theoretical support for the preparation of activated carbon and high-quality solid biofuels from different layers of corncob.