Influence of high carbonization temperatures on microstructural and physicochemical characteristics of herbaceous biomass derived biochars

This study investigated the influence of high carbonization temperatures on the microstructural, textural, and physicochemical characteristics of Kanlow Switchgrass and Public Miscanthus derived biochars. Biochars were produced at three carbonization temperatures of 500, 700 and 900 degrees C. pH values of the biochars increased from slightly alkaline to highly alkaline as carbonization temperature increased. Electrical conductivities of the biochars were between 1.21 and 4.07 mS/cm. The specific surface areas of the Kanlow Switchgrass derived biochars increased from 0.91 to 519.49 m(2)/g and 0.25 to 783.74 m(2)/g for Public Miscanthus derived biochars as carbonization temperature increased. Surface topographies of the biochars showed that all the biochars had visible pores of varying sizes and shapes. Raman spectra for all the biochars showed overlapping D and G bands. XPS analysis showed a reduction in the atomic percentage of oxygen functional groups as carbonization temperature increased. The improvement in the characteristics of the biochars showed that high carbonization temperatures can significantly enhance the satisfactory performance of herbaceous biomass-derived biochar as a solid fuel, adsorbent, and soil amendment.