Conversion of bio-derived phenolic compounds into aromatic hydrocarbons by co-feeding methanol over γ-Al2O3. (1st December 2018) - Si, Zhan
Graphical abstract: Highlights: A novel route for converting phenolic compounds to aromatic hydrocarbons is proposed. The γ-Al2 O3 catalyst shows high activity in co-cracking of guaiacol and methanol. Co-feeding methanol effectively promotes guaiacol conversion and inhibits coke formation. Abstract: In the present study, a novel route of upgrading lignin pyrolysis vapor to aromatic hydrocarbons was investigated. Guaiacol was used as model compound to investigate the coupling conversion of pyrolysis vapor and methanol. Co-feeding methanol obviously facilitated the conversion of guaiacol to aromatic hydrocarbons and inhibited coke formation. HZSM-5, Al-MCM-41 and γ-Al2 O3 catalysts were screened, and γ-Al2 O3 showed the best catalytic activity for the catalytic co-cracking reaction due to the appropriate acid property. The effects of methanol to guaiacol molar ratio, reaction temperature and W/Fguaiacol on product distribution over γ-Al2 O3 were studied in a fixed bed reactor to reveal the reaction mechanism. As hydrogen donor, the co-fed methanol promoted the deoxygenation of guaiacol. The water formed through methanol dehydration was an efficient agent for attenuating coke deposition. The highest yield of aromatic hydrocarbons was 81.2% when the methanol to guaiacol molar ratio was 25 at 400 °C. The investigation of W/Fguaiacol indicated that the synergistic effect of co-feeding was sensitive at lower W/Fguaiacol . Co-feeding methanol with phenol, anisole and the phenolic mixture were also investigated, and high yields of aromatic hydrocarbons were obtained, which demonstrated that co-feeding methanol was a promising process for upgrading complicated pyrolysis products.