Effect of Aging on Physicochemical Properties of Biochars

Aging incubation experiments of natural aging, high temperature aging and freeze-thaw aging for 5 months were carried out by using four biochars prepared by pyrolysis of biomass involving pine chip, corn straw, wheat straw and peanut shell. The effects of aging method on the physiochemical properties of biochars were investigated based on the determination of ultimate analysis, scanning electron microscope (SEM), N2 adsorption/desorption analyzer, X-ray diffractometer (XRD), Fourier infrared spectrometer (FTIR) and pH measurement. The obtained results showed that the aging process can significantly lead to increasing BET specific surface area, improving micro-pore structure, decreasing C element content, increasing O element content and the molar ratios of H/C, O/C and (O+N)/C, and the development of surface oxygen-containing functional groups resulting in lower pH. The improvement effect of aging method on biochar physiochemical properties is ordered as high temperature aging > freeze-thaw aging > natural aging. © 2021, Science Press. All right reserved.