(24d) Aromatic Hydrocarbons Production From Catalysis of Douglas Fir Sawdust Pellets Pyrolysis Vapor Over Zeolite Catalyst

Direct catalytic cracking of biomass pyrolysis vapor into aromatics derived from Douglas fir sawdust pellets was tested using an upfront microwave pyrolysis process coupled with a packed-bed catalysis process using a ZSM-5 Zeolite catalyst. A central composite experimental design (CCD) was used to optimize the bio-oil and syngas yields. The effects of temperature and inverse weight hourly space velocity (WHSV)^-1 on the bio-oil composition were determined. GC/MS analysis results showed that the bio-oil contained aromatic hydrocarbons and no oxygen containing compounds. Aromatic hydrocarbons were enriched and become the most abundant compounds accounting for about 15-92.6% in upgraded bio-oils depending on the catalytic pyrolysis conditions. The aromatic hydrocarbons were mainly composed of benzene, toluene, xylene, naphthalene, and there derivatives. When the effect of reaction temperature on bio-oil chemical compositions was analyzed with a fixed (WHSV)^-1 (0.048h) we found that the aromatic hydrocarbons were increased from 0.72% in raw bio-oil (no catalyst added) to around 92.6% when the catalysis temperature was 500^°C clearly demonstrating that high temperature with the ZSM-5 Zeolite catalyst favored the production of aromatic hydrocarbons. At a lower temperature fixed at 375^°C, the aromatic hydrocarbon content was increased from 0.72% to 78.1% with (WHSV)^-1 increase from 0 to 0.075.