Microwave-assisted catalytic pyrolysis of torrefied corn cob for phenol-rich bio-oil production over Fe modified bio-char catalyst

Microwave-assisted catalytic pyrolysis of torrefied corn cob into phenol-rich bio-oil on Fe modified bio-char catalyst was investigated in this study. The well-developed surface pore was confirmed by scanning electronic microscope (SEM) images and nitrogen adsorption/desorption isotherms, indicating that the porous structure of bio-char depended on the Fe modification to a large extent. Temperature-programmed desorption of NH₃ (NH₃-TPD) analysis showed that the Fe modified bio-char catalyst mainly presented strong acid sites. The use of bio-char catalyst can decrease the bio-oil yield and increase the gas yield but the biochar did not experience any significant change because of the ex-situ catalysis mode. Catalytic pyrolysis of torrefied corn cob using Fe modified bio-char catalyst was able to produce the higher yields and selectivities of phenol and cresol, where the catalytic performance of the bio-char catalyst was superior to commercial activated carbon. In addition, the catalyst deactivation and regenation tests were also conducted to evaluate the service life of the catalyst.