Aaron M. Jubb
Patrick L. Smith
Ryan J. McAleer
Brett J. Valentine
Javin J. Hatcherian
Palma J. Botterell
Justin E. Birdwell
Paul C. Hackley
2022
<p><span>Geological models for petroleum generation suggest <a class="topic-link" title="Learn more about thermal conversion from ScienceDirect's AI-generated Topic Pages" href="https://www.sciencedirect.com/topics/engineering/thermal-conversion" data-mce-href="https://www.sciencedirect.com/topics/engineering/thermal-conversion">thermal conversion</a> of oil-prone sedimentary organic matter in the presence of water promotes increased liquid saturate yield, whereas absence of water causes formation of an aromatic, cross-linked solid <a class="topic-link" title="Learn more about bitumen from ScienceDirect's AI-generated Topic Pages" href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/bitumen" data-mce-href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/bitumen">bitumen</a> residue. To test the influence of hydrogen from water, organic-rich (22 wt% <a class="topic-link" title="Learn more about total organic carbon from ScienceDirect's AI-generated Topic Pages" href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/total-organic-carbon" data-mce-href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/total-organic-carbon">total organic carbon</a>, TOC) <a class="topic-link" title="Learn more about mudrock from ScienceDirect's AI-generated Topic Pages" href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/mudstone" data-mce-href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/mudstone">mudrock</a> samples from the <a class="topic-link" title="Learn more about Eocene from ScienceDirect's AI-generated Topic Pages" href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/eocene" data-mce-href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/eocene">Eocene</a> lacustrine Green River Formation Mahogany zone <a class="topic-link" title="Learn more about oil shale from ScienceDirect's AI-generated Topic Pages" href="https://www.sciencedirect.com/topics/engineering/oil-shale" data-mce-href="https://www.sciencedirect.com/topics/engineering/oil-shale">oil shale</a> were pyrolyzed under hydrous and anhydrous conditions in closed system <a class="topic-link" title="Learn more about batch reactors from ScienceDirect's AI-generated Topic Pages" href="https://www.sciencedirect.com/topics/engineering/batch-reactor" data-mce-href="https://www.sciencedirect.com/topics/engineering/batch-reactor">batch reactors</a> at temperatures between 300 and 370 °C for 72 h. Pre- and post-pyrolysis samples were characterized using petrographic approaches including <a class="topic-link" title="Learn more about optical microscopy from ScienceDirect's AI-generated Topic Pages" href="https://www.sciencedirect.com/topics/engineering/optical-microscopy" data-mce-href="https://www.sciencedirect.com/topics/engineering/optical-microscopy">optical microscopy</a>, reflectance, </span><a class="topic-link" title="Learn more about Raman spectroscopy from ScienceDirect's AI-generated Topic Pages" href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/raman-spectroscopy" data-mce-href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/raman-spectroscopy">Raman spectroscopy</a><span>, and scanning electron and <a class="topic-link" title="Learn more about transmission electron microscopy from ScienceDirect's AI-generated Topic Pages" href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/transmission-electron-microscopy" data-mce-href="https://www.sciencedirect.com/topics/earth-and-planetary-sciences/transmission-electron-microscopy">transmission electron microscopy</a> to quantify differences in relative appearance, abundance, and composition of solid bitumen newly generated during the pyrolysis experiments. Petrographic analyses were supplemented by geochemical screening measurements (TOC content and programmed temperature pyrolysis). Results show post-hydrous pyrolysis residues contain lower TOC, are comprised of solid bitumen with greater <a class="topic-link" title="Learn more about aromaticity from ScienceDirect's AI-generated Topic Pages" href="https://www.sciencedirect.com/topics/engineering/aromaticity" data-mce-href="https://www.sciencedirect.com/topics/engineering/aromaticity">aromaticity</a>, and have textures indicative of lower viscosities, relative to anhydrous residues from the same temperature pyrolysis conditions. These observations suggest solid bitumen forming from thermal conversion of oil-prone sedimentary organic matter under anhydrous conditions may be less aromatic, although more cross-linked, than solid bitumen forming under hydrous conditions at the same time-temperature combination. To explain these results, we suggest that a radical <a class="topic-link" title="Learn more about disproportionation from ScienceDirect's AI-generated Topic Pages" href="https://www.sciencedirect.com/topics/engineering/disproportionation" data-mce-href="https://www.sciencedirect.com/topics/engineering/disproportionation">disproportionation</a> mechanism is favored in the presence of hydrogen donated from water, and that this disproportionation promotes aromatization in the <a class="topic-link" title="Learn more about solid residue from ScienceDirect's AI-generated Topic Pages" href="https://www.sciencedirect.com/topics/engineering/solid-residue" data-mce-href="https://www.sciencedirect.com/topics/engineering/solid-residue">solid residue</a> with concomitant expulsion of saturated hydrocarbons.</span></p>
application/pdf
10.1016/j.coal.2022.104016
en
Elsevier
Evaluating aromatization of solid bitumen generated in the presence and absence of water: Implications for solid bitumen reflectance as a thermal proxy
article