Bai, Z;
Jiang, XZ;
Luo, KH;
(2022)
Effects of water on pyridine pyrolysis: A reactive force field molecular dynamics study.
Energy
, 238
(Part B)
, Article 121798. 10.1016/j.energy.2021.121798.
(In press).
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Abstract
The emission of nitrogen oxides (NOx) from coal combustion causes serious environmental problems. Fuel splitting and staging is a promising method for NOx control by combustion modification. In this process, nitrogen-containing compounds generated from pyrolysis gas play an important role in regulating NOx generation. Water from coal could potentially change reactions during the coal pyrolysis process. Adjusting the content of water in coal may be an effective way to control coal pyrolysis reactions. This work aims to investigate the effects of water on pyridine (a main nitrogen-containing compound in coal) pyrolysis via reactive force field (ReaxFF) molecular dynamics (MD) simulations. Results indicate that the addition of water during the pyridine pyrolysis process increases the number of OH radicals in the system and accelerates the consumption of pyridine at the initial stage. However, at a later stage, water inhibits the consumption of pyridine as it impedes the condensation reaction of pyridine molecules. Common and unique intermediates are identified and quantified under various water-content conditions. Results suggest that water also reduces the proportion of nitrogen atoms in the polycondensation product. Furthermore, ring opening processes of pyridine molecules are reproduced at the atomic level. The changes in reaction pathways due to the presence of water are also revealed. The new insights into the mechanisms of pyridine pyrolysis under water and water-free conditions provide a possibility to control nitrogen migration during the pyrolysis process, which is of great significance to emission reduction from coal combustion.
| Type: | Article |
|---|---|
| Title: | Effects of water on pyridine pyrolysis: A reactive force field molecular dynamics study |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1016/j.energy.2021.121798 |
| Publisher version: | http://dx.doi.org/10.1016/j.energy.2021.121798 |
| Language: | English |
| Additional information: | © 2021 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). |
| Keywords: | Pyridine pyrolysis, Water, Reactive force field molecular dynamics, Reaction pathway |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Mechanical Engineering |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10134426 |
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