{"title":"Investigation of the Driving Force of Replacing Adsorbed Hydrocarbons by CO2 in Organic Matter from an Energy Perspective","authors":"Xinyi Zhao, Qian Sang, Mingzhe Dong and Jun Yao*, ","doi":"10.1021/acs.langmuir.4c00910","DOIUrl":null,"url":null,"abstract":"<p >Carbon dioxide (CO<sub>2</sub>) has been widely used to enhance the recovery of adsorbed hydrocarbons from the organic matter (OM) in shale formations. To reveal the driving force of replacing adsorbed hydrocarbons from OM by CO<sub>2</sub>, we performed molecular dynamics (MD) simulations of the replacement process and calculated the interaction forces between CO<sub>2</sub> and hydrocarbons. In addition, based on the umbrella sampling method, steered MD simulations were performed, and the free energy profiles of hydrocarbons were obtained using the weighted histogram analysis method. Results show that the condition of the hydrocarbon replacement by CO<sub>2</sub> requires the hydrocarbon to have sufficient kinetic energy or to have a sufficiently large attractive force exerted to ensure that the hydrocarbon escapes the potential well of the OM. The attractive forces exerted on hydrocarbon molecules by CO<sub>2</sub> can significantly decrease the energy barrier associated with hydrocarbon movement away from the OM surface. Furthermore, both CO<sub>2</sub> and supercritical CO<sub>2</sub> can effectively displace adsorbed hydrocarbon gas (methane) on the OM, while supercritical CO<sub>2</sub> is required to enhance the recovery of adsorbed hydrocarbon oil (<i>n</i>-dodecane). The results obtained in this study provide guidance for enhancing the recovery of adsorbed hydrocarbons by CO<sub>2</sub> in shale formations.</p>","PeriodicalId":50,"journal":{"name":"Langmuir","volume":null,"pages":null},"PeriodicalIF":3.7000,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Langmuir","FirstCategoryId":"92","ListUrlMain":"https://pubs.acs.org/doi/10.1021/acs.langmuir.4c00910","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Carbon dioxide (CO2) has been widely used to enhance the recovery of adsorbed hydrocarbons from the organic matter (OM) in shale formations. To reveal the driving force of replacing adsorbed hydrocarbons from OM by CO2, we performed molecular dynamics (MD) simulations of the replacement process and calculated the interaction forces between CO2 and hydrocarbons. In addition, based on the umbrella sampling method, steered MD simulations were performed, and the free energy profiles of hydrocarbons were obtained using the weighted histogram analysis method. Results show that the condition of the hydrocarbon replacement by CO2 requires the hydrocarbon to have sufficient kinetic energy or to have a sufficiently large attractive force exerted to ensure that the hydrocarbon escapes the potential well of the OM. The attractive forces exerted on hydrocarbon molecules by CO2 can significantly decrease the energy barrier associated with hydrocarbon movement away from the OM surface. Furthermore, both CO2 and supercritical CO2 can effectively displace adsorbed hydrocarbon gas (methane) on the OM, while supercritical CO2 is required to enhance the recovery of adsorbed hydrocarbon oil (n-dodecane). The results obtained in this study provide guidance for enhancing the recovery of adsorbed hydrocarbons by CO2 in shale formations.
二氧化碳(CO2)已被广泛用于提高页岩层中有机物(OM)吸附碳氢化合物的回收率。为了揭示 CO2 取代 OM 中吸附的碳氢化合物的驱动力,我们对取代过程进行了分子动力学(MD)模拟,并计算了 CO2 与碳氢化合物之间的相互作用力。此外,基于伞状采样方法,我们还进行了转向 MD 模拟,并利用加权直方图分析方法获得了碳氢化合物的自由能曲线。结果表明,碳氢化合物被二氧化碳置换的条件要求碳氢化合物具有足够的动能或施加足够大的吸引力,以确保碳氢化合物逃离 OM 的势阱。二氧化碳对碳氢化合物分子施加的吸引力可大大降低碳氢化合物远离 OM 表面的能量障碍。此外,二氧化碳和超临界二氧化碳都能有效地置换 OM 上吸附的烃类气体(甲烷),而要想提高吸附的烃类石油(正十二烷)的采收率,则需要超临界二氧化碳。本研究获得的结果为利用二氧化碳提高页岩层中吸附烃的采收率提供了指导。
期刊介绍:
Langmuir is an interdisciplinary journal publishing articles in the following subject categories:
Colloids: surfactants and self-assembly, dispersions, emulsions, foams
Interfaces: adsorption, reactions, films, forces
Biological Interfaces: biocolloids, biomolecular and biomimetic materials
Materials: nano- and mesostructured materials, polymers, gels, liquid crystals
Electrochemistry: interfacial charge transfer, charge transport, electrocatalysis, electrokinetic phenomena, bioelectrochemistry
Devices and Applications: sensors, fluidics, patterning, catalysis, photonic crystals
However, when high-impact, original work is submitted that does not fit within the above categories, decisions to accept or decline such papers will be based on one criteria: What Would Irving Do?
Langmuir ranks #2 in citations out of 136 journals in the category of Physical Chemistry with 113,157 total citations. The journal received an Impact Factor of 4.384*.
This journal is also indexed in the categories of Materials Science (ranked #1) and Multidisciplinary Chemistry (ranked #5).