A novel pathway to clean production of phenol-rich bio-oil and syngas by catalytic pyrolysis of pretreated lignin was investigated for the first time. The process integrated pretreatment and catalysis. The results revealed that the optimal condition for phenol selectivity (95.5%) from unpretreated lignin pyrolysis was achieved at a pyrolytic temperature of 550 °C with catalyst/lignin ratio of 0.7. Lignin pretreatment boosted the volatile production as well as syngas formation. A significant increase in the phenol concentration (from 0.6 to 7.0 mg/mL) for pretreated lignin was achieved at pretreated temperature of 50 °C for 60 min. During the deactivation test, the catalyst exhibited a benign catalytic performance for phenol selectivity after using four times. Further, the “phenol pool” and free radical were proposed to uncover the mechanism of phenol generation from catalytic conversion of pretreated lignin. These findings pave a new and clean route to produce high-purity phenol, which could ultimately advance the utilization of lignin through facile fix-bed catalytic pyrolysis technology.
Bibliographical noteFunding Information:
We would like to acknowledge the Agriculture and Food Research Initiative Competitive Grant No. 2016-67021-24533 , 2018-67009-27904 , and 2014-38502-22598 from the National Institute of Food and Agriculture , United States Department of Agriculture. Furthermore, we would like to thank the National Natural Science Foundation of China (No. 21766019 , 21878137 ), Key Research and Development Program of Jiangxi Province ( 20171BBF60023 ), China Scholarship Council (No. 201706820027 ) and Xcel Energy. We are grateful to Dr. Aftab Ahamed for helping with the GC/MS analysis.
- Activated carbon
- Catalytic pyrolysis
- Phenol-rich bio-oil