Catalytic pyrolysis of biomass components over mesoporous catalysts using Py-GC/MS

Abstract

In this study, large pore mesoporous materials, SBA-15 catalysts (SBA-15, Pt/SBA-15, AlSBA-15, and Pt/AlSBA-15), were applied to catalytic pyrolysis of three biomass constituents: cellulose, hemicellulose, and lignin. The catalytic performance was evaluated by analyzing the composition of the products. The catalysts were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), nitrogen adsorption, and NH3 temperature programmed desorption (NH3-TPD). SBA-15 was shown to have few acid sites, whereas AlSBA-15 had considerable amount of acid sites that are advantageous for dehydration, cracking, decarbonylation, etc. The catalytic performances of AlSBA-15 and Pt/AlSBA-15 were better than those of SBA-15 and Pt/SBA-15. In particular, catalytic upgrading over Pt/AlSBA-15 resulted in the largest yields of high value-added species like furans and aromatics. During the pyrolysis of cellulose, levoglucosan, a main product of noncatalytic pyrolysis, was converted by catalytic upgrading into high value-added species such as furans and aromatics. The catalytic upgrading of the pyrolysis product of hemicellulose also increased the yields of furan, ethanol, and aromatics, improving the quality of the bio-oil. One drawback of the catalytic upgrading was the increased production of acids including acetic acid both for cellulose and hemicellulose. Catalytic pyrolysis of lignin increased the production of phenolics, especially, with less amount of carbonyl group.