Characterization of emulsified water in petroleum sludge
Characterization of emulsified water in petroleum sludge
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DOI：
10.1016/j.fuel.2013.10.053
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发表时间：
2014-02
期刊：
影响因子：
7.4
通讯作者：
Qun-xing Huang;F. Mao;Xu Han;Jian-hua Yan;Y. Chi
中科院分区：
文献类型：
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作者：
Qun-xing Huang;F. Mao;Xu Han;Jian-hua Yan;Y. Chi
常规石油资源的日益枯竭已引起人们对从石油污泥中回收石油资源的兴趣。为了提高采出油的质量，必须最大限度地去除乳化水、溶解盐和其他杂质。因此，本研究采用差示扫描量热法（DSC）对石油污泥中的乳化水滴和盐进行表征。为此，在离心前后对三种不同类型的样品进行了评估。结果表明，在- 60℃至室温的控制加热过程中，可以通过DSC检测到盐水合物的含水量和共晶。此外，根据50 ~ - 60℃DSC热像图的冷却阶段，提出了一个新的计算水滴大小分布的方程。混合石油污泥储罐和清洗废水储罐样品中均含有乳化水滴，粒径分布变宽，冻结峰随着水滴直径的增大从- 44°C移至- 20°C。此外，原油储罐样品中的水滴乳化非常强，且相对均匀，直径为2.7 ~ 3.3 μm。离心后，上层油层中有小液滴，说明水/油/固相分离前的脱乳化预处理是获得高纯度油品资源的必要条件。这是DSC首次用于石油污泥中乳化水的表征和水滴粒径分布的推导。这些结果对石油污泥处理工艺的优化具有重要的指导意义。
Increasing depletion of conventional oil resources has driven interest in recovery of oil resources from petroleum sludge. To improve the quality of recovered oil, it is essential to maximize the removal of emulsified water, dissolved salts, and other impurities. Therefore, this study was conducted to characterize the emulsified water droplets and salt in petroleum sludge through differential scanning calorimetry (DSC). To accomplish this, samples of three different types were evaluated before and after centrifugation. The results indicated that with DSC water content and eutectic of salt hydrates could be identified during controlled heating from −60 °C to room temperature. Moreover, a new equation to retrieve water droplets size distribution according to the cooling phase of the DSC thermogram from 50 °C to −60 °C is proposed. Samples collected from a mixed petroleum sludge storage tank and a tank cleaning wastewater reservoir were found to contain emulsified water droplets with a broadened size distribution, and the freezing peaks shifted from −44 °C to −20 °C as the diameter of water droplets increased. Additionally, water droplets in the sample collected from the crude oil storage tank were very strongly emulsified and were relatively uniform, with a diameter of 2.7–3.3 μm. Following centrifugation, small droplets were found in the upper oily layer, suggesting that de-emulsification pre-treatment prior to water/oil/solid phase separation is essential to obtain high-purity oil resources. This is the first time DSC is employed to characterize emulsified water and deduce water droplets size distribution in petroleum sludge. These results are essential and useful for optimization of petroleum sludge treatment.