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Effect of microwave and thermal co-pyrolysis of low rank coal and pine wood on product distributions and char structure

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Show simple item record Abdelsayed, Victor Ellison, Candice Trubetskaya, Anna Smith, Mark Shekhawat, Dushyant 2019-11-28T09:33:39Z 2019
dc.description peer-reviewed en_US
dc.description.abstract Direct conversion of a low-rank coal into valuable chemicals or improving its char’s coking value became very demanding goals in coal utilization strategies. In this work, the co-pyrolysis of a low-rank lignite coal and pine wood sawdust biomass blended at a 3:1 coal-to-biomass ratio was investigated along with original coal and biomass samples by microwave assisted and conventional thermal methods at 550℃ under nitrogen and ambient pressure. The carbon structure and its reactivity in generated chars and the product distributions were greatly affected by the applied heating mechanism and the presence of biomass during coal pyrolysis. High gas and low tar yields were observed for all microwave chars in comparison to thermal chars, regardless of composition. The addition of biomass to coal increased the tar yield under both methods and to a higher extent under the microwave. This agrees with the high gas yield and high aromatic-to-aliphatic fraction observed under the microwave and the presence of biomass. The high O/C ratio and low fixed carbon content in a biomass structure relative to coal affect the product distribution during microwave pyrolysis. This could selectively heat the biomass in the sample, remove its polar groups, and convert it into an efficient microwave absorber biochar that can decompose coal efficiently during co-pyrolysis. The aromatic carbon stacking and its ordering in the generated chars were investigated by powder X-ray diffraction, Raman spectroscopy, dielectric property measurements, and electron spin resonance techniques. A synergistic effect was observed upon biomass addition during microwave coal pyrolysis. Electron spin resonance spectroscopy revealed that the microwave coal/biomass char is the most stable char with the lowest free radical concentration. This agrees with the highest IG/Iall band area ratio calculated from Raman analysis revealing a more graphitic nature for carbon in this char. Similarly, the dielectric properties confirmed that the addition of biomass to coal under the microwave has the highest loss tangent, indicating a high graphitic nature compared to pure biochar or coal char. en_US
dc.language.iso eng en_US
dc.publisher American Chemical Society en_US
dc.relation.ispartofseries Energy Fuels;33 (8), pp. 7069-7082
dc.rights © 2019 ACS This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal Title, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see en_US
dc.subject lignite coal en_US
dc.subject microwave en_US
dc.subject co-pyrolysis en_US
dc.subject biomass en_US
dc.subject char characteristics en_US
dc.subject dielectric en_US
dc.subject radical concentration en_US
dc.subject pine wood en_US
dc.subject ESR en_US
dc.title Effect of microwave and thermal co-pyrolysis of low rank coal and pine wood on product distributions and char structure en_US
dc.type info:eu-repo/semantics/article en_US
dc.type.supercollection all_ul_research en_US
dc.type.supercollection ul_published_reviewed en_US
dc.identifier.doi 10.1021/acs.energyfuels.9b01105
dc.contributor.sponsor Department of Energy, National Energy Technology Laboratory en_US 2020-07-07
dc.embargo.terms 2020-07-07 en_US
dc.rights.accessrights info:eu-repo/semantics/openAccess en_US

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