Py-GC/MS analysis on product distribution of two-staged biomass pyrolysis

Two-staged pyrolysis of biomass was proposed as a promising method by which liquid products would be less diverse and more concentrated, and beneficial to further upgrading or extracting chemicals. Rice straw, cedar wood, and dalbergia wood were selected as representative biomass materials. Thermogravimetric Fourier-transform infrared spectroscopy (TG-FTIR) was initially used to analyze biomass and the three main components. According to the pyrolysis characteristics and the volatile release processes, 270-360 degrees C was selected as the optional temperature range for the low-temperature stage of the two-staged pyrolysis. Then, Pyrolysis Gas Chromatography Mass Spectrometry (Py-GC/MS) was used in two stages to analyze three types of biomass, with the first stage at 270 degrees C, 320 degrees C, or 360 degrees C and then the second stage at 550 degrees C. The two-staged pyrolysis could efficiently separate biomass pyrolysis products, especially the enrichment of organic acids, alcohols, and aldehydes in the first stage, and the enrichment of phenolic substances in the second stage. The optimum temperature of the first stage was 320 degrees C, which was suitable for three different kinds of biomass.