Catalytic pyrolysis of biomass using shape-selective zeolites for bio-oil enhancement

Biomass pyrolysis produces valuable solid, liquid, and gas products. However, the liquid products observed low heating value due to low hydrocarbon contents with the presence of high oxygenated species. To upgrade the bio-oil, appropriate solid acid catalysts are incorporated in the biomass pyrolysis process to deoxygenate the species to enhance the heating value of the bio-oil called catalytic upgrading process. The study presents the progress of catalytic pyrolysis process using shape-selective zeolites for improving hydrocarbon in the bio-oil. To compare the performance, commercial and synthesis microporous zeolites are tested in the in situ catalytic pyrolysis process. ZSM-5, ferrite, and mordenite were the commercial zeolites at the Si/Al ratio of 23, 20, and 20, respectively, are employed. On the other hand, layered MCM-22 (20) and its counterpart ITQ-2 (20) were synthesized using established protocol and tested in catalytic biomass pyrolysis process in drop-type pyrolyzer. These zeolites are categorized as various pore sizes, shapes, and acidity which impacts on deoxygenation performance. Among synthesized zeolites, ITQ-2 showed higher deoxygenation which results in increased aromatics production. Overall, ZSM-5 appeared as the most suitable catalyst for higher deoxygenation with higher aromatics production in comparison to other shape-selective zeolites.