Improved Light Hydrocarbon, Furans, and BTEX Production from the Catalytic Assisted Pyrolysis of Agave salmiana Bagasse over Silica Mesoporous Catalysts

Abstract

The pyrolysis of the biomass Agave salmiana bagasse (10 K/min, ambient to 700 °C) was investigated in the absence and presence of Aerosil and MCM-41 catalysts. MCM-41 was synthetized using a typical hydrothermal method and characterized with XRD, SAXS, SEM, TEM, and nitrogen physisorption to confirm the presence of unidimensional 3.4 nm diameter pores. Pyrolysis products were monitored online with mass spectrometry (MS), analyzing the production of 29 different compounds, clustered in several groups, namely, olefins (ethene, 2-butene, 1,3-butadiene), oxygenated compounds (methanol, 2-methylbutanol, acetic acid), furan derivatives (furan, furfural, 2-methylfurane), and aromatic compounds (BTEX). Complete decomposition of the cellulose and hemicellulose content of the biomass was observed at temperatures below 400 °C. Lignin decomposition was completed by 550 °C. Catalyst-assisted pyrolysis showed reduced acetic acid and methanol formation with Aerosil and MCM-41. The use of Aerosil does not affect the overall production of olefins, yet increases benzene yield, while reducing the production of phenol, furan, and furan derivatives. With MCM-41, there is increased production of olefins, furan, furan derivatives, cyclohexanone and BTEX, yet phenol production is decreased. At temperatures below 400 °C, the product formation pattern is comparable to non-catalytic pyrolysis.