Catalytic fast hydropyrolysis of seaweed biomass with different zeolite catalysts to produce high-grade bio-oil

Abstract

This paper studies the conversion of seaweed into liquid fuels through catalytic fast hydropyrolysis (CHP) with microporous ZSM-5, mesoporous MCM-41 and their mixtures for high-quality bio-oil production. Although the catalytic fast pyrolysis could increase bio-oil yield, the higher content of acids, furans and phenols in bio-oil were produced in the N2 atmosphere, which could aggravate the catalyst deactivation and increase thermal instability. The pyrolysis process in the presence of H2 with no catalyst showed a minor impact on the production yields. While the synergy of H2 with ZSM-5 and MCM-41 was found to substantially increase the bio-oil yield 36.22 % to 51.48 % and 41.84 %, respectively. Moreover, the CHP process not only increased the bio-oil yield but also enhanced its quality. Besides, entire aromatics content in the bio-oil from the CHP process increased, whereas the small molecule acids contents declined. Also, alcohol and ester content increased by 10.40 % and 3.58 %, respectively. Furthermore, furans and ketones were not detected, and the denitrification reactions were also improved with the co-catalyst. The present results suggest that CHP can be a viable way to convert seaweed biomass into liquid bio-fuel.