Study on pine sawdust pyrolysis behavior by fast pyrolysis under inert and reductive atmospheres

Fast pyrolysis of pine sawdust (PS) was investigated in a drop tube quartz reactor to understand the effects of temperature and atmosphere (Ar and H-2) on the product yields, gas composition, bio-oil characteristics (organic composition and molecular mass distributions (MMDs)), and the carbon and oxygen conversion. The pyrolysis behavior and typical products from PS pyrolysis were also conducted using a thermogravimetry-mass spectroscopy (TG-MS) and pyrolysis-gas-chromatography/mass spectrometry (Py-GC/MS). The results show that the highest oil yields can be obtained at 500 degrees C of 55.09 and 54.41 wt.% under Ar and H-2 atmosphere, respectively. In comparison to an inert atmosphere, H-2 created lower oil yields but higher gas yields, especially for CO and CH4 yields, and narrower MMDs, smaller M-n and M-w, and fewer char especially at high temperatures. The high temperatures and H-2 atmosphere contribute to the oxygen and carbon transferring from material to volatile, especially to the gaseous products. H-2 can promote the secondary cracking of macromolecules and weaken the re-polymerization of anhydrosugar and lignin oligomers. (C) 2017 Elsevier B.V. All rights reserved.