Cascaded Catalytic Copyrolysis of Microalgae and LDPE with Ni/Biochar and HZSM-5 for Improving High-Grade Bio-Oil Production
Lei Liu, Wenguang Zhou, Yunpu Wang, Yinghua Yao, Jun Qian, Jiabo Wu, Jinye Hu, Mengjiao Wang, Weixin Wang, Ting Luo, Kuangli Jin, Liangliang Fan
Abstract
The N and O elements of microalgae are mainly responsible for the low quality of the bio-oil, and it is difficult to completely remove the heteroatomic compounds by any single catalyst. In this study, the tandem catalysts of Ni/biochar and HZSM-5 were used for the catalytic copyrolysis of microalgae and low-density polyethylene (LDPE). The tandem catalysts improved the product yield and conversion rate compared to Ni/biochar or HZSM-5 alone. Higher addition of LDPE also favored feedstock conversion. During the cascaded catalytic pyrolysis, up to 100% of C 5 –C 12 hydrocarbons, including 48.6% for BTX, were obtained. The selectivity of C 5 –C 12 hydrocarbons was increased by 45.2% due to the synergistic effect of the two catalysts. The copyrolysis process improved the production of C 5 –C 12 hydrocarbons with the highest synergistic degree of 83.1% and resulted in the complete removal of N and O. The plausible pathway for the formation of aromatics and short-chain hydrocarbons was elucidated based on the synergistic effects.