(144c) Stability of Pyrolysis Oils Produced From Auger and Entrained Flow Reactors

Pyrolysis oil or bio-oil currently has tremendous potential to be used as a heavy fuel oil (ASTM No. 4) substitute meeting the 21st century energy demand at least partially. Pyrolysis oil can be produced from divergent feed stocks including waste biomass such as forestry residues, saw dust, bark, chicken litter, demolition wood, used tires, and others. The increased fuel energy density compared to raw biomass accompanied by negligible waste production from pyrolysis provides attractive options to the pyrolysis oil producers. Environmental benefits of pyrolysis oil include significantly lower green house gas (GHG) emissions as compared to the fossil fuels. Furthermore, the utility of pyrolysis oil as a light fuel oil (ASTM No. 2) can be likely achieved by upgrading techniques such as catalytic hydrodeoxygenation, hot vapor filtration, and solvent addition. Being a novel liquid fuel in the today's market both chemical and physical properties (density, viscosity, pH, water content, flash point etc) of pyrolysis oil need to be studied extensively before its engine application. During the authors' investigation, solvent addition technique was explored to increase the storage stability of pyrolysis oils, and possibly further the understanding of their chemical mechanisms. As such, pyrolysis oils are widely known to undergo polymeric chemical reactions which are detrimental to their long-term (ASTM definition ≥ 1 yr) storage stability. Hence, a detailed study was undertaken to investigate the storage stability of pyrolysis oils by varying feedstock, reactor, and storage conditions. A wide range of chemical additives with optimized concentrations were evaluated to stabilize the pyrolysis oils. The entire investigation was conducted in four phases and the results obtained during these phases will be discussed in detail at the forthcoming annual AICHE meeting.