The high concentration of oxygenated compounds in pyrolytic products prohibits the conversion of hemicellulose to important biofuels and chemicals via fast pyrolysis. Herein a dual-catalyst bed of CaO and HZSM-5 was developed to convert acids in the pyrolytic products of xylan to valuable hydrocarbons. Meanwhile, LLDPE was co-pyrolyzed with xylan to supplement hydrogen during the catalysis of HZSM-5. The results showed that CaO could effectively transform acids into ketones. A minimum yield of acids (2.74%) and a maximum yield of ketones (42.93%) were obtained at a catalyst to feedstock ratio of 2:1. The dual-catalyst bed dramatically increased the yield of aromatics. Moreover, hydrogen-rich fragments derived from LLDPE promoted the Diels-Alder reactions of furans and participated in the hydrocarbon pool reactions of non-furanic compounds. As a result, a higher yield of hydrocarbons was achieved. This study provides a fundamental for recovering energy and chemicals from pyrolysis of hemicellulose.
Bibliographical noteFunding Information:
This research is supported by in part by the National Natural Science Foundation of China ( 21766019 ), the Key Research and Development Program of Jiangxi Province ( 20171BBF60023 ), China, the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative‐Citizen Commission on Minnesota Resources (LCCMR), and the University of Minnesota Center for Biorefining.
- Catalytic fast co-pyrolysis
- Dual-catalyst bed
- Upgraded bio-oil production