249 / 2023-07-20 14:07:11

油页岩恒温氧化热解实验及机理研究

油页岩;恒温氧化热解;反应模型

The reasonable introduction of oxygen to the in situ conversion process of oil shale can effectively reduce energy consumption, and during this process, temperature is a crucial factor. In this work, we study the isothermal oxidative pyrolysis behavior of two oil shales differing in total organic carbon (TOC) at constant temperatures (225, 285, 340, 400, and 445 ℃). Quantitative analysis of pyrolysis reactants and products was performed through multiple approaches, including gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS), Rock-Eval analysis, and elemental organic analysis. The results indicated that with the increase in reaction temperature, two reaction regimes can be distinguished, low-temperature oxidative pyrolysis (LTOP) and high-temperature oxidative pyrolysis (HTOP), where the transition temperature is approximately 340 ℃. In the LTOP process, low-temperature oxygen addition, isomerization, and decomposition reactions mainly occurred, while in the HTOP process, high-temperature oxidation, pyrolysis, and coke oxidation reactions dominated. Accordingly, a temperature-dependent reaction model of oxidative pyrolysis of oil shale in isothermal conditions was validated and the real-time change in the reaction rates was obtained. The oxidative pyrolysis of oil shale is found to be significantly enhanced with the increase in temperature. Also, oil shale with a higher TOC has a more intense reaction and a higher transition temperature of HTOP and LTOP. This work provides a theoretical basis for the further application of oxidative pyrolysis in oil shale exploitation.



油页岩原位转化过程中，氧气的合理引入可以有效降低热解所需的外部能耗，而在此过程中，反应温度是一个至关重要的因素。本文研究了两种总有机碳(TOC)含量不同的油页岩在恒温条件下(225、285、340、400和445℃)的氧化热解行为。通过气相色谱(GC)、气相色谱-质谱(GC-MS)、Rock-Eval分析和元素有机分析等多种方法对热解反应物和产物进行定量分析，以确定反应物与生成物的组成与含量。结果表明，随着反应温度的升高，反应可分为低温氧化热解(LTOP)和高温氧化热解(HTOP)两种反应模式，其中LTOP与HTOP的临界温度约为340℃。LTOP以低温氧加成、异构化、分解反应为主，HTOP以高温氧化、热解、焦炭氧化反应为主。据此，建立了与温度相关的恒温条件下油页岩氧化热解反应模型，并获得了反应速率的实时变化曲线。随着温度的升高，油页岩的氧化热解反应明显增强。此外，TOC更高的油页岩反应更剧烈，HTOP和LTOP的临界温度更高。本研究为氧化热解技术在油页岩开采中的进一步应用提供了理论基础。