Impacts of Anisotropic Porosity on Heat Transfer and Off-Gassing during Biomass Pyrolysis

dc.contributor.author Pecha, M. Brennan
dc.contributor.author Thornburg, Nicholas E.
dc.contributor.author Peterson, Chad A.
dc.contributor.author Crowley, Meagan F.
dc.contributor.author Gao, Xi
dc.contributor.author Lu, Liqiang
dc.contributor.author Wiggins, Gavin
dc.contributor.author Ciesielski, Peter N.
dc.contributor.department Mechanical Engineering
dc.contributor.department Agricultural and Biosystems Engineering
dc.contributor.department Chemical and Biological Engineering
dc.contributor.department Bioeconomy Institute
dc.date.accessioned 2021-12-16T16:08:07Z
dc.date.available 2021-12-16T16:08:07Z
dc.date.issued 2021-12-16
dc.description.abstract The pore structure of biogenic materials imbues the ability to deliver water and nutrients through a plant from root to leaf. This anisotropic pore granularity can also play a significant role in processes such as biomass pyrolysis that are used to convert these materials into useful products like heat, fuel, and chemicals. Evolutions in modeling of biomass pyrolysis as well as imaging of pore structures allow for further insights into the concerted physics of phase change-induced off-gassing, heat transfer, and chemical reactions. In this work, we report a biomass single particle model which incorporates these physics to explore the impact of implementing anisotropic permeability and diffusivity on the conversion time and yields predicted for pyrolysis of oak and pine particles. Simulation results showed that anisotropic permeability impacts predicted conversion time more than 2 times when the Biot number is above 0.1 and pyrolysis numbers (Py1, Py2) are less than 20. Pore structure significantly impacts predicted pyrolytic conversion time (>8 times) when the Biot number is above 1 and the pyrolysis number is below 1, i.e., the “conduction controlled” regime. Therefore, these nondimensional numbers reflect that when internal heat conduction limits pyrolysis performance, internal pyrolysis off-gassing further retards effective heat transfer rates as a closely coupled phenomenon. Overall, this study highlights physically meaningful opportunities to improve particle-scale pyrolysis modeling and experimental validation relevant to a variety of feedstock identities and preparations, guiding the future design of pyrolyzers for efficient biomass conversion.
dc.description.comments This article is published as Pecha, M. Brennan, Nicholas E. Thornburg, Chad A. Peterson, Meagan F. Crowley, Xi Gao, Liqiang Lu, Gavin Wiggins, Robert C. Brown, and Peter N. Ciesielski. "Impacts of Anisotropic Porosity on Heat Transfer and Off-Gassing during Biomass Pyrolysis." Energy & Fuels (2021). DOI: 10.1021/acs.energyfuels.1c02679. Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/avVODmdr
dc.language.iso en_US
dc.publisher American Chemical Society
dc.source.uri https://doi.org/10.1021/acs.energyfuels.1c02679 *
dc.subject pyrolysis
dc.subject single particle model
dc.subject permeability
dc.subject diffusion
dc.subject heat transfer
dc.subject.disciplines DegreeDisciplines::Engineering::Mechanical Engineering::Energy Systems
dc.title Impacts of Anisotropic Porosity on Heat Transfer and Off-Gassing during Biomass Pyrolysis
dc.type Article
dspace.entity.type Publication
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