Quantitative analysis of primary tar yields volatilized from biomass (Effect of heating rate and biomass type on tar components)

Although rapid pyrolysis affords higher volatile yield than slow pyrolysis, the change in the yield of components at different heating rates have not been reported in detail. Moreover, few studies have assessed the changes in the tar component yield with respect to biomass type. Therefore, from a practical point of view, this study quantitatively determined the effects of the heating rate and biomass type on the tar component yield through gas chromatography–mass spectrometry. In addition, the mechanism of tar formation was investigated. The main results of the study are as follows: (1) Changes in the yield and component of biomass tar due to increase in the heating rate by a factor of 100 were quantitatively determined. An increased heating rate resulted in a higher yield of aromatic compounds and induced the formation of benzene, toluene, and other compounds. At slow heating rates, the yield of odorous components such as vanillin, furfural, acids, and aldehydes increased. At the middle heating rate (1.0 K/s), a significant increase in the amount of phenols containing OH and O groups was observed. (2) For woody biomass, acetic acid, cellulose-derived glucose, catechol, phenols, and furfural were identified as the major tar components. (3) The tar components volatilized from the wood trunk, bark, and grass are affected by the primary content of the biomass constituents.