Production of aromatic hydrocarbons from lignin derivatives by catalytic cracking over a SiO2–Al2O3 catalyst?

RSC Advances Pub Date: 2023-04-05 DOI: 10.1039/D3RA00990D

Abstract

Catalytic cracking of phenolic compounds to aromatic hydrocarbons is vital to the utilization of lignin. In this work, pristine amorphous SiO2–Al2O3 was used as a catalyst to produce aromatic hydrocarbons from lignin-derived phenolics by catalytic cracking using methanol as the solvent. These catalysts were characterized by various techniques (XRD, NH3-TPD, Py-IR, etc.) and evaluated on a fixed bed reactor using guaiacol as a model compound. The effects of reaction temperature, the flow of carrier gas, the molar ratio of guaiacol to methanol, and WHSV were investigated. 33-SA (SiO2–Al2O3 with the SiO2 content of 33%) exhibited the best catalytic activity due to its high content of Lewis acid sites (168.47 μmol g?1). Co-feeding with methanol promoted the removal of oxygen atoms and improved the reaction system H/Ceff. Under the optimal conditions of 400 °C, 25 mL min?1 N2, a molar ratio of methanol to guaiacol of 25, and WHSV of 8/3 h?1, the yield of aromatic hydrocarbons reached 57.93%. The deactivating species in the transformation of guaiacol into aromatic hydrocarbons on catalysts were also studied.

Graphical abstract: Production of aromatic hydrocarbons from lignin derivatives by catalytic cracking over a SiO2–Al2O3 catalyst
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