Arene production by W2C/MCM-41-catalyzed upgrading of vapors from fast pyrolysis of lignin

Abstract

W2C/MCM-41-catalyzed upgrading of vapors from fast pyrolysis of lignin was investigated with the aim of arene production. The experiments were conducted in a micro pyrolyzer-gas chromatography/mass spectrometer (P-GC/MS). A series of W2C/MCM-41 catalysts with different catalyst loading amount (Si/W) were prepared and the activity, selectivity, and stability of the catalysts were investigated. Associated with the analysis results of P-GC/MS for the pyrolysis vapors, the optimal condition for producing arenes was found. Besides, possible mechanisms for lignin conversion with the as-prepared catalysts were discussed. In the presence of W2C/MCM-41 (Si/W=50), the arenes yield is about 20% of volatile product and the selectivity for monocyclic arenes is over 85% at 750°C. The yield of arenes increases significantly with the increase of catalyst-to-lignin mass ratio (C/L). According to the run tests, the conversion of arenes decreases slightly by 1% or 2% after each run, indicating that the catalyst features good stability under the experimental conditions. Thus, W2C/MCM-41 catalysts effectively catalyzed the formation of monocyclic arenes in the fast pyrolysis process.