Phosphorus doped biochar as a deoxygenation and denitrogenation catalyst for ex-situ upgrading of vapors from microwave-assisted co-pyrolysis of microalgae and waste cooking oil

• Published in: Journal of analytical and applied pyrolysis 2022-06, Vol.164, p.105538, Article 105538
• Main Authors: Su, Zheyang, Jin, Kuangli, Wu, Jiabo, Huang, Pei, Liu, Lei, Xiao, Zhiguo, Peng, Hongyu, Fan, Liangliang, Zhou, Wenguang
• Format: Article
• Language: English
• Subjects: Denitrogenation; Deoxygenation; Microalgae; Phosphorus P-doped biochar; Waste cooking oil
• ISSN: 0165-2370; 1873-250X
• DOI: 10.1016/j.jaap.2022.105538

High oxygen and nitrogen issues should be addressed to upgrade microalgae pyrolytic oil. In this study, phosphorus-doped (P-doped) biochar was acquired and applied to the catalytic microwave co-pyrolysis of Chlorella and waste cooking oil (WCO). The effects of catalyst-to-feedstock ratio and Chlorella-to-WCO ratio on the product yields and distributions were studied, and the maximum selectivity of hydrocarbons (92.22%), in which 52.35% was mono-aromatics, as well as the highest content of H2 (35.26%) were obtained. During the process, the nitrogenous and oxygenated compounds were effectively removed by 88.8% and 83.2%, respectively. Moreover, P-doped biochar recycling usage resulted in lower production of aromatics and syngas (H2 and CO). The characterization of P-doped biochar helped reveal the catalytic conversion mechanism. The current study offered a potential approach of converting microalgae and WCO into light hydrocarbons by converting nitrogenous and oxygenated compounds. [Display omitted] •P-doped biochar was used for the study of deoxygenation and denitrogenation.•Nitrogenates and oxygenates contents were effectively removed by 88.8% and 83.2%.•The highest selectivity of aromatics was 63.15% in that 52.35% was mono-aromatics.•The synergistic extents of mono-aromatics and H2 were 46.37% and 25.37%.•The catalyst characterizations helped to elucidate the co-pyrolysis pathways.