Critical impacts of pyrolysis conditions and activation methods on application-oriented production of wood waste-derived biochar

• DOI: 10.1016/j.biortech.2021.125811
• Publication Date: 2021-08-20T23:44:23Z
• Authors: Mingjing He; Zibo Xu; Yuqing Sun; P.S. Chan; Iris Lui; Daniel C.W. Tsang
• Keywords: Charcoal; Carbon fibers

Wood waste-derived biochar with tunable carbon structure and surface functionality has a great potential for various environmental applications and circular economy; however, a holistic understanding on the application-oriented production of high-efficacy biochar is lacking. Thus, the co-impacts of different pyrolysis conditions (temperature and duration) and activation methods (steam, CO2, and acid pretreatment) on the biochar properties were first investigated. A temperature of 650 ℃ was effective in forming carbonized structure in biochar, while 750 ℃ was critical for the porous structure development. A longer pyrolysis duration (>60 min) enhanced the pore volume without compromising the yield. The activated biochar exhibited a larger pore volume (2.1- to 2.9-fold of pristine biochar) for potential high-end emerging applications. The acid pretreatment effectively removed dissolved organic carbon and most metals from the biochar. This study provides an essential guidance on the fit-for-purpose designs of biochar production conditions for sustainable wood waste management.