Optimization of Biochar Production from Spent Activated Carbon for Anaerobic Biodegradation Enhancement

Abstract

In this study, effects of temperatures (117-683°C) and heating rates (1.9-23.1 °C/min) on pH and specific surface area (SSA) of biochar produced from the pyrolysis of spent activated carbon (SAC) were investigated. Experiments were designed based on the Central Composite Design (CCD) technique. Results showed that the highest pH and SSA of 11.24 and 998 m2/g were obtained under the temperature and heating rate of 683°C and 12.5 °C/min, respectively. These pH and SSA values were found to be 28% and 18% higher than those of the unprocessed SAC. The pH and SSA values achieved were found to be in the same range as those capable of increasing biogas production from different feedstocks in the literature.