Production of aromatic hydrocarbons from lignin derivatives by catalytic cracking over a SiO(2)–Al(2)O(3) catalyst

Catalytic cracking of phenolic compounds to aromatic hydrocarbons is vital to the utilization of lignin. In this work, pristine amorphous SiO(2)–Al(2)O(3) 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, NH(3)-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 (SiO(2)–Al(2)O(3) with the SiO(2) 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/C(eff). Under the optimal conditions of 400 °C, 25 mL min(−1) N(2), 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.