In Situ Upgrading of Cellulose Pyrolysis Volatiles Using Hydrofluorinated and Platinum-Loaded HZSM-5 for High Selectivity Production of Light Aromatics

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

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/C_eff. 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.

Catalytic cracking of phenolic compounds to aromatic hydrocarbons is vital to the utilization of lignin.

Catalytic Pyrolysis of Nonedible Oils for the Production of Renewable Aromatics Using Metal-Modified HZSM-5 Catalysts

Catalytic pyrolysis of triglycerides to aromatics over zeolites is an advanced technology for a high value-added utilization of renewable biomass resources. Therefore, in this research, the catalytic performance of M/HZSM-5 catalysts (M = Zn, Ga, In, Ni, and Mo) during the pyrolysis process of glycerol trioleate and the effect of the compositional difference of several woody oils and waste oils on aromatic formation were investigated. Results revealed that Zn/HZSM-5 with appropriate acidity and metal sites reached the maximum aromatics yield (56.13%) and significantly enhanced the catalytic stability. In addition, these renewable nonedible oils were effectively converted to aromatics over the Zn/HZSM-5 catalyst, the aromatic yield of jatropha oil reached up to 50.33%, and the unsaturation and double bond number of feedstocks were crucial for the production of aromatics. The utilization of biomass resources to produce high value-added aromatics can alleviate the problems caused by the shortage of fossil resources and achieve sustainable green development.