Product Yield and Characterization of Biochar from Senna Siamea via Slow Pyrolysis Process

Abstract

This study focused on examining the yield and characteristics of biochar derived from Siamese cassia wood via a slow pyrolysis method in a 200 L reactor under oxygen-restricted conditions at a pyrolysis temperature of 500 °C. The findings showed that the yields of biochar, gas, and wood vinegar were 46.15, 52.54, and 1.31% by weight, respectively. The analysis of the generated biochar indicated that the moisture level, volatile matter, ash percentage, fixed carbon, and higher heating value were recorded at 2.47, 14.11, 4.63, 78.79% by weight, and 26.48 MJ/kg, respectively. These characteristics met the Thai Community Product Standard for cooking charcoal (TCPS 657/2547), demonstrating the superior quality of the produced biochar. Moreover, the pyrolysis temperature and heating rate were recognized as crucial elements affecting product yield. Heating rates that are low to moderate increased biochar production while reducing carbon loss throughout the pyrolysis process. The results indicate that biochar obtained from Siamese cassia wood shows significant promise for use as a soil amendment and a substitute solid fuel for community-level purposes.