State-of-the-art and the future directions of glycerol transformation to bio-based aromatics via catalytic pyrolysis over zeolite catalysts

The formation of bio-aromatics via glycerol catalytic pyrolysis is one of the glycerol valorization strategies as biodiesel's by-product. Bio-aromatics is one of the most promising molecules that are applicable in a wide range of industries. The catalytic pyrolysis of glycerol over Mordenite Framework Inverted (MFI-type) zeolite as a catalyst exhibits a high yield of aromatics in a range of 20 %-80 %. In contrast, Beta (BEA-type) zeolite exhibit a lower yield of aromatics around 10 %-67 %, while Theta-one (TON-type) zeolite is less selective towards the glycerol transformation into aromatics due to its typical needle shape with a length of a few micrometers, which possibly limits the formation of the oligomers. This review comprehensively discussed various zeolites as a catalyst for catalytic pyrolysis of glycerol. Additionally, the economic evaluation of the pyrolysis process is present.