Efficient ex-situ catalytic upgrading of biomass pyrolysis vapors to produce methylfurans and phenol over bio-based activated carbon

Analytical pyrolysis-comprehensive two-dimensional gas chromatography/mass spectrometry (Py-GC x GC/MS) was used for the on-line analysis of pyrolysis vapors. Bio-based activated carbon (B-AC) catalysts were used to produce highly selectivity valuable chemicals such as furans and phenols. B-AC catalyst was subjected to several characterizations to investigate the physicochemical properties of the catalyst and its relationship with products distribution. The results showed that B-AC catalyst showed high catalytic activity and selectivity for the production of furans and phenols under mild catalytic temperature (350 degrees C). Furans are mainly from pyrolysis of cellulose and hemicellulose, while phenols are mainly from pyrolysis of lignin. Methylfurans and phenol were dominated compounds. With the use of B-AC, the relative peak area of methylfurans increased from 6.58% to 39.35% (cellulose), 0%-27.79% (xylan), 0.54%-26.82% (corncob); the relative peak area of phenol increased from 6.31% to 53.83% (lignin) and 2.77%-12.34% (corncob). A significant reduction of aldehydes, ketones, and sugars was also observed over B-AC catalyst. The higher total acidity (weak acidity and Lewis acidity) of B-AC favored the formation of 2-methylfuran and phenol.