Production of MAH-rich bio-oil from co-pyrolysis of biomass and plastics using carbonized MOF catalysts under microwave irradiation

This study investigates the effects of various carbonized MOF catalysts on the properties of products derived from microwave-assisted co-pyrolysis of biomass and plastics. The Cr@C catalysts were prepared from MIL-101(Cr) precursors at different microwave carbonization temperatures, while Fe/Cr@C catalysts were synthesized under varying Fe loadings. Characterization of the catalysts was performed using XRD, BET, and FT-IR. The distribution of solid, liquid, and gaseous products, as well as the composition of bio-oil and syngas, were analyzed. The results show that the 5Fe/Cr@C catalyst achieved the highest pyrolysis gas yield (33.05 wt%), while the 15Fe/Cr@C catalyst produced the highest hydrogen yield (24.97 vol%). The Cr@C catalyst promoted hydrocarbon production, with Cr@C-700 achieving a total hydrocarbon content of 51.04 %. The incorporation of Fe enhanced the selectivity of Cr@C catalysts for monocyclic aromatic hydrocarbons(MAHs) in the bio-oil. The aromatic content reached a maximum of 19.88 % with the 15Fe/Cr@C catalyst. Notably, the MAHs content in the 5Fe/Cr@C catalyst accounted for 97.1 % of the total aromatic hydrocarbons. This research provides valuable insights into the potential of carbonized MOF catalysts for producing bio-oil rich in single-ring aromatic hydrocarbons from microwave-assisted co-pyrolysis of biomass and plastics.