New insights into the pyrolysis of -tetradecane using ReaxFF molecular dynamics simulations: Implications for understanding the thermal cracking of subsurface crude oil
The fragmentation of normal alkanes during the cracking of oil under geochemical conditions with high thermal stress is important for the preservation of crude oils in reservoirs and the formation of gaseous hydrocarbons. In this study, the kinetics behavior, cracking mechanisms, and products of n -...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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SAGE Publishing
2023-01-01
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| Series: | Energy Exploration & Exploitation |
| Online Access: | https://doi.org/10.1177/01445987221131111 |
| _version_ | 1811207231744507904 |
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| author | Meijun Li Qiuya Han Xiaoqiang Liu Jin Xu Haochen Chen Yuanyuan Ma |
| author_facet | Meijun Li Qiuya Han Xiaoqiang Liu Jin Xu Haochen Chen Yuanyuan Ma |
| author_sort | Meijun Li |
| collection | DOAJ |
| description | The fragmentation of normal alkanes during the cracking of oil under geochemical conditions with high thermal stress is important for the preservation of crude oils in reservoirs and the formation of gaseous hydrocarbons. In this study, the kinetics behavior, cracking mechanisms, and products of n -tetradecane pyrolysis were investigated using reactive molecular dynamics (ReaxFF MD) simulations at high temperatures (2000K∼3000 K). The pyrolysis process itself, its main products and intermediates, and kinetic behavior were analyzed at an atomic/molecular level. Low molecular weight (C 1 –C 5 ) alkanes and olefins, together with H 2 , were the predominant intermediates and products of the simulations. Three distinct stages—a stable stage, initial decomposition, and secondary pyrolysis—can be distinguished during the decomposition process. The reactant n -tetradecane was exhausted when the simulation temperature reaches ∼2250 K, accompanied by a rapid increase in hydrocarbons with molecular numbers C 1 –C 5 . The yield of C 2 –C 5 peaked at ∼2500 K and then decreased. The number of CH 4 molecules increased continuously throughout the entire simulation process because of the contribution of secondary pyrolysis. The Arrhenius parameters obtained from ReaxFF MD simulations, on the basis of first-order kinetic analysis of n -tetradecane, were reasonably consistent with experimental data and generally in agreement with results from pyrolysis experiments on crude oils in the laboratory. The pyrolysis process and reaction mechanism of n -tetradecane were also reasonably consistent with laboratory pyrolysis experiments on whole oils and their individual components. ReaxFF molecular dynamics simulation is therefore considered to be a valid approach for the study of thermal cracking of subsurface crude oils. |
| first_indexed | 2024-04-12T03:59:30Z |
| format | Article |
| id | doaj.art-91fe1df1d27c49ce930a40440bb09f87 |
| institution | Directory Open Access Journal |
| issn | 0144-5987 2048-4054 |
| language | English |
| last_indexed | 2024-04-12T03:59:30Z |
| publishDate | 2023-01-01 |
| publisher | SAGE Publishing |
| record_format | Article |
| series | Energy Exploration & Exploitation |
| spelling | doaj.art-91fe1df1d27c49ce930a40440bb09f872022-12-22T03:48:44ZengSAGE PublishingEnergy Exploration & Exploitation0144-59872048-40542023-01-014110.1177/01445987221131111New insights into the pyrolysis of -tetradecane using ReaxFF molecular dynamics simulations: Implications for understanding the thermal cracking of subsurface crude oilMeijun Li0Qiuya Han1Xiaoqiang Liu2Jin Xu3Haochen Chen4Yuanyuan Ma5 State Key Laboratory of Petroleum Resources and Prospecting, College of Geosciences, 102249, China State Key Laboratory of Petroleum Resources and Prospecting, College of Geosciences, 102249, China College of Chemistry and Environmental Engineering, , Zigong 643000, China , Petroleum Exploration and Production Research Institute, SINOPEC, Wuxi, Jiangsu 214216, China State Key Laboratory of Petroleum Resources and Prospecting, College of Geosciences, 102249, China , Petroleum Exploration and Production Research Institute, SINOPEC, Wuxi, Jiangsu 214216, ChinaThe fragmentation of normal alkanes during the cracking of oil under geochemical conditions with high thermal stress is important for the preservation of crude oils in reservoirs and the formation of gaseous hydrocarbons. In this study, the kinetics behavior, cracking mechanisms, and products of n -tetradecane pyrolysis were investigated using reactive molecular dynamics (ReaxFF MD) simulations at high temperatures (2000K∼3000 K). The pyrolysis process itself, its main products and intermediates, and kinetic behavior were analyzed at an atomic/molecular level. Low molecular weight (C 1 –C 5 ) alkanes and olefins, together with H 2 , were the predominant intermediates and products of the simulations. Three distinct stages—a stable stage, initial decomposition, and secondary pyrolysis—can be distinguished during the decomposition process. The reactant n -tetradecane was exhausted when the simulation temperature reaches ∼2250 K, accompanied by a rapid increase in hydrocarbons with molecular numbers C 1 –C 5 . The yield of C 2 –C 5 peaked at ∼2500 K and then decreased. The number of CH 4 molecules increased continuously throughout the entire simulation process because of the contribution of secondary pyrolysis. The Arrhenius parameters obtained from ReaxFF MD simulations, on the basis of first-order kinetic analysis of n -tetradecane, were reasonably consistent with experimental data and generally in agreement with results from pyrolysis experiments on crude oils in the laboratory. The pyrolysis process and reaction mechanism of n -tetradecane were also reasonably consistent with laboratory pyrolysis experiments on whole oils and their individual components. ReaxFF molecular dynamics simulation is therefore considered to be a valid approach for the study of thermal cracking of subsurface crude oils.https://doi.org/10.1177/01445987221131111 |
| spellingShingle | Meijun Li Qiuya Han Xiaoqiang Liu Jin Xu Haochen Chen Yuanyuan Ma New insights into the pyrolysis of -tetradecane using ReaxFF molecular dynamics simulations: Implications for understanding the thermal cracking of subsurface crude oil Energy Exploration & Exploitation |
| title | New insights into the pyrolysis of -tetradecane using ReaxFF molecular dynamics simulations: Implications for understanding the thermal cracking of subsurface crude oil |
| title_full | New insights into the pyrolysis of -tetradecane using ReaxFF molecular dynamics simulations: Implications for understanding the thermal cracking of subsurface crude oil |
| title_fullStr | New insights into the pyrolysis of -tetradecane using ReaxFF molecular dynamics simulations: Implications for understanding the thermal cracking of subsurface crude oil |
| title_full_unstemmed | New insights into the pyrolysis of -tetradecane using ReaxFF molecular dynamics simulations: Implications for understanding the thermal cracking of subsurface crude oil |
| title_short | New insights into the pyrolysis of -tetradecane using ReaxFF molecular dynamics simulations: Implications for understanding the thermal cracking of subsurface crude oil |
| title_sort | new insights into the pyrolysis of tetradecane using reaxff molecular dynamics simulations implications for understanding the thermal cracking of subsurface crude oil |
| url | https://doi.org/10.1177/01445987221131111 |
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