Deoxygenation of wheat straw fast pyrolysis vapors using HZSM-5, Al2O3, HZSM-5/Al2O3 extrudates, and desilicated HZSM-5/Al2O3 extrudates

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Abstract

HZSM-5 extrudates, its two constituents (HZSM-5 zeolite and alumina binder), and SiC for reference were tested after steam treatment for the upgrading of wheat straw fast pyrolysis (FP) vapors from an ablative bench scale system. In addition, mesoporosity was added to the HZSM-5 crystals of the zeolite/Al2O3 extrudates by desilication, which decreased the microporous volume and led to enhanced weak acidity and less strong acidity compared to the parent extrudates. For increasing biomass-to-catalyst ratios (w/w, B:C), oils were collected and analyzed for elemental composition, total acid number (TAN), moisture, molecular weight, evaporation characteristics, and chemical composition by gas chromatography mass spectrometry with flame ionization detection (GC-MS/FID), 1H nuclear magnetic resonance (NMR), 13C NMR, and two-dimensional heteronuclear single-quantum correlation (2D HSQC) NMR. Compared to Al2O3, catalysts containing HZSM-5 promoted aromatization and limited the coke formation due to its shape selective micropores. Nevertheless, Al2O3 was effective in deoxygenation. At B:C ~7, 23 wt-% carbon/25 % energy recovery in the oil fraction was obtained while reducing the oxygen content by 45 % relative to a thermal reference oil fraction obtained over a SiC bed. As such, Al2O3 offers certain benefits compared to HZSM-5 based catalysts due to its lower cost and better hydrothermal stability with respect to acidity. At a catalyst temperature of 500 °C, the introduction of mesopores to HZSM-5 extrudates led to higher energy recovery as oil compared to the parent HZSM-5 extrudates. At B:C = 6.3, 23 wt-% carbon/26% energy recovery in the oil phase was achieved while removing 45% of the oxygen functionalities relative to the thermal reference bio-oil. Compared to deep deoxygenation for direct hydrocarbon production, mild deoxygenation improved the energy recoveries of the oil fractions and appears viable for pretreating pyrolysis vapors before co-processing bio-oils with fossil oil in refineries.
Original languageEnglish
JournalEnergy & Fuels
Volume33
Issue number7
Pages (from-to)6405-6420
ISSN0887-0624
DOIs
Publication statusPublished - 2019

Cite this

@article{8a1260c514404dae99a4e3c842733984,
title = "Deoxygenation of wheat straw fast pyrolysis vapors using HZSM-5, Al2O3, HZSM-5/Al2O3 extrudates, and desilicated HZSM-5/Al2O3 extrudates",
abstract = "HZSM-5 extrudates, its two constituents (HZSM-5 zeolite and alumina binder), and SiC for reference were tested after steam treatment for the upgrading of wheat straw fast pyrolysis (FP) vapors from an ablative bench scale system. In addition, mesoporosity was added to the HZSM-5 crystals of the zeolite/Al2O3 extrudates by desilication, which decreased the microporous volume and led to enhanced weak acidity and less strong acidity compared to the parent extrudates. For increasing biomass-to-catalyst ratios (w/w, B:C), oils were collected and analyzed for elemental composition, total acid number (TAN), moisture, molecular weight, evaporation characteristics, and chemical composition by gas chromatography mass spectrometry with flame ionization detection (GC-MS/FID), 1H nuclear magnetic resonance (NMR), 13C NMR, and two-dimensional heteronuclear single-quantum correlation (2D HSQC) NMR. Compared to Al2O3, catalysts containing HZSM-5 promoted aromatization and limited the coke formation due to its shape selective micropores. Nevertheless, Al2O3 was effective in deoxygenation. At B:C ~7, 23 wt-{\%} carbon/25 {\%} energy recovery in the oil fraction was obtained while reducing the oxygen content by 45 {\%} relative to a thermal reference oil fraction obtained over a SiC bed. As such, Al2O3 offers certain benefits compared to HZSM-5 based catalysts due to its lower cost and better hydrothermal stability with respect to acidity. At a catalyst temperature of 500 °C, the introduction of mesopores to HZSM-5 extrudates led to higher energy recovery as oil compared to the parent HZSM-5 extrudates. At B:C = 6.3, 23 wt-{\%} carbon/26{\%} energy recovery in the oil phase was achieved while removing 45{\%} of the oxygen functionalities relative to the thermal reference bio-oil. Compared to deep deoxygenation for direct hydrocarbon production, mild deoxygenation improved the energy recoveries of the oil fractions and appears viable for pretreating pyrolysis vapors before co-processing bio-oils with fossil oil in refineries.",
author = "Andreas Eschenbacher and Jensen, {Peter Arendt} and Henriksen, {Ulrik Birk} and Jesper Ahrenfeldt and Chengxin Li and Duus, {Jens {\O}llgaard} and Mentzel, {Uffe Vie} and Jensen, {Anker Degn}",
year = "2019",
doi = "10.1021/acs.energyfuels.9b00906",
language = "English",
volume = "33",
pages = "6405--6420",
journal = "Energy & Fuels",
issn = "0887-0624",
publisher = "American Chemical Society",
number = "7",

}

TY - JOUR

T1 - Deoxygenation of wheat straw fast pyrolysis vapors using HZSM-5, Al2O3, HZSM-5/Al2O3 extrudates, and desilicated HZSM-5/Al2O3 extrudates

AU - Eschenbacher, Andreas

AU - Jensen, Peter Arendt

AU - Henriksen, Ulrik Birk

AU - Ahrenfeldt, Jesper

AU - Li, Chengxin

AU - Duus, Jens Øllgaard

AU - Mentzel, Uffe Vie

AU - Jensen, Anker Degn

PY - 2019

Y1 - 2019

N2 - HZSM-5 extrudates, its two constituents (HZSM-5 zeolite and alumina binder), and SiC for reference were tested after steam treatment for the upgrading of wheat straw fast pyrolysis (FP) vapors from an ablative bench scale system. In addition, mesoporosity was added to the HZSM-5 crystals of the zeolite/Al2O3 extrudates by desilication, which decreased the microporous volume and led to enhanced weak acidity and less strong acidity compared to the parent extrudates. For increasing biomass-to-catalyst ratios (w/w, B:C), oils were collected and analyzed for elemental composition, total acid number (TAN), moisture, molecular weight, evaporation characteristics, and chemical composition by gas chromatography mass spectrometry with flame ionization detection (GC-MS/FID), 1H nuclear magnetic resonance (NMR), 13C NMR, and two-dimensional heteronuclear single-quantum correlation (2D HSQC) NMR. Compared to Al2O3, catalysts containing HZSM-5 promoted aromatization and limited the coke formation due to its shape selective micropores. Nevertheless, Al2O3 was effective in deoxygenation. At B:C ~7, 23 wt-% carbon/25 % energy recovery in the oil fraction was obtained while reducing the oxygen content by 45 % relative to a thermal reference oil fraction obtained over a SiC bed. As such, Al2O3 offers certain benefits compared to HZSM-5 based catalysts due to its lower cost and better hydrothermal stability with respect to acidity. At a catalyst temperature of 500 °C, the introduction of mesopores to HZSM-5 extrudates led to higher energy recovery as oil compared to the parent HZSM-5 extrudates. At B:C = 6.3, 23 wt-% carbon/26% energy recovery in the oil phase was achieved while removing 45% of the oxygen functionalities relative to the thermal reference bio-oil. Compared to deep deoxygenation for direct hydrocarbon production, mild deoxygenation improved the energy recoveries of the oil fractions and appears viable for pretreating pyrolysis vapors before co-processing bio-oils with fossil oil in refineries.

AB - HZSM-5 extrudates, its two constituents (HZSM-5 zeolite and alumina binder), and SiC for reference were tested after steam treatment for the upgrading of wheat straw fast pyrolysis (FP) vapors from an ablative bench scale system. In addition, mesoporosity was added to the HZSM-5 crystals of the zeolite/Al2O3 extrudates by desilication, which decreased the microporous volume and led to enhanced weak acidity and less strong acidity compared to the parent extrudates. For increasing biomass-to-catalyst ratios (w/w, B:C), oils were collected and analyzed for elemental composition, total acid number (TAN), moisture, molecular weight, evaporation characteristics, and chemical composition by gas chromatography mass spectrometry with flame ionization detection (GC-MS/FID), 1H nuclear magnetic resonance (NMR), 13C NMR, and two-dimensional heteronuclear single-quantum correlation (2D HSQC) NMR. Compared to Al2O3, catalysts containing HZSM-5 promoted aromatization and limited the coke formation due to its shape selective micropores. Nevertheless, Al2O3 was effective in deoxygenation. At B:C ~7, 23 wt-% carbon/25 % energy recovery in the oil fraction was obtained while reducing the oxygen content by 45 % relative to a thermal reference oil fraction obtained over a SiC bed. As such, Al2O3 offers certain benefits compared to HZSM-5 based catalysts due to its lower cost and better hydrothermal stability with respect to acidity. At a catalyst temperature of 500 °C, the introduction of mesopores to HZSM-5 extrudates led to higher energy recovery as oil compared to the parent HZSM-5 extrudates. At B:C = 6.3, 23 wt-% carbon/26% energy recovery in the oil phase was achieved while removing 45% of the oxygen functionalities relative to the thermal reference bio-oil. Compared to deep deoxygenation for direct hydrocarbon production, mild deoxygenation improved the energy recoveries of the oil fractions and appears viable for pretreating pyrolysis vapors before co-processing bio-oils with fossil oil in refineries.

U2 - 10.1021/acs.energyfuels.9b00906

DO - 10.1021/acs.energyfuels.9b00906

M3 - Journal article

VL - 33

SP - 6405

EP - 6420

JO - Energy & Fuels

JF - Energy & Fuels

SN - 0887-0624

IS - 7

ER -