Comprehensive investigations into low temperature oxidation of heavy crude oil
Comprehensive investigations into low temperature oxidation of heavy crude oil
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DOI：
10.1016/j.petrol.2018.08.027
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发表时间：
2018-12
影响因子：
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通讯作者：
Shuai Zhao;W. Pu;M. Varfolomeev;C. Yuan;Ji-zhou Zhang;Han Xiaoqiang;Yang Yang-Yang;Xiao-qiang Peng;Wu Junxue
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文献类型：
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作者：
Shuai Zhao;W. Pu;M. Varfolomeev;C. Yuan;Ji-zhou Zhang;Han Xiaoqiang;Yang Yang-Yang;Xiao-qiang Peng;Wu Junxue
鉴于低温氧化（LTO）过程对后续氧化反应和原位燃烧（ISC）采油的重要意义，本研究旨在对重质原油的低温氧化（LTO）过程进行一系列全面的研究。通过静态氧化实验分析了稠油的LTO行为。然后通过焦炭含量测定、可燃性测试和扫描电镜（SEM）观察，研究了LTO对油品特性的影响。此外，利用热重法(TG)/差示扫描量热法（DSC）技术研究了LTO对稠油热行为和动力学的影响。结果表明，温度对稠油LTO的影响至关重要。在80 °C时几乎没有焦炭沉积。160 °C时焦炭沉积量平均为0.346 g焦炭/g油，约为120 °C时的4.2倍。160 °C氧化油在环境温度和大气压下的可燃性优于80和120 °C氧化油。160 ℃氧化油及其形成的焦炭表面形貌相当粗糙，促进了随后的燃烧反应。TG/DSC结果表明，与原油相比，氧化油在燃料沉积（FD）和高温氧化（HTO）阶段遭受了更高的质量损失和放热效应。静态LTO后，稠油LTO和FD阶段的活化能增加，而HTO阶段的活化能降低。与原油和氧化油相比，静态LTO过程中沉积的焦炭在HTO区间的热释放和反应活性最高。本文可以为稠油LTO机理的研究提供一些新的见解，以丰富ISC技术。
Due to the significance of low temperature oxidation (LTO) process on the subsequent oxidation reactions and oil recovery for in situ combustion (ISC), this work aimed at conducting a series of comprehensive investigations into LTO of heavy crude oil. The LTO behavior of heavy oil was analyzed by static oxidation experiments. Then the alterations in oil characteristics due to LTO were investigated through coke content measurements, flammability tests and scanning electron microscopic (SEM) observations. Additionally, the effect of LTO on thermal behavior and kinetics of heavy oil was researched using thermogravimetry (TG)/differential scanning calorimetry (DSC) technique. The results showed that the temperature played a crucial role in LTO of heavy oil. Almost no coke was deposited at 80 °C. The amount of coke deposition at 160 °C averaged 0.346 g coke/g oil, which was roughly 4.2 times higher than that at 120 °C. The oxidized oil at 160 °C possessed the most superior flammability at ambient temperature and atmospheric pressure in comparison to that at 80 and 120 °C. The surface morphologies of oxidized oil at 160 °C and its formed coke were quite rough, which boosted the subsequent combustion reactions. The results of TG/DSC unravelled that the oxidized oils were subjected to higher mass loss and exothermic effect at the fuel deposition (FD) and high temperature oxidation (HTO) stages as compared to crude oil. After the static LTO, the activation energy in the LTO and FD stages for heavy oil was increased, while that in the HTO stage was reduced. Compared with crude oil and oxidized oils, the coke deposited during the static LTO presented the highest thermal release and reaction activity in the HTO interval. This paper can provide some new insights regarding LTO mechanisms of heavy oil to rich the ISC technology.