Department of Chemical Engineering, King Fahd University of Petroleum and Minerals, Dhahran, 31261, Saudi Arabia.
Center for Integrative Petroleum Research, King Fahd University of Petroleum and Minerals, Dhahran, 31261, Saudi Arabia.
Sci Rep. 2023 Jan 19;13(1):1090. doi: 10.1038/s41598-023-27973-x.
Efficient demulsifiers for fast demulsification of asphaltene stabilized crude oil emulsions are currently in high demand. In this work, we evaluated the demulsification potential of ethyl cellulose (EC) demulsifiers with varying viscosities-4 cp, 22 cp, and 100 cp, designated as EC-4, EC-22, and EC-100. Demulsifcation efficiency (DE) of these demulsifiers to remove water from emulsions produced from distilled water, seawater, and different salts (NaCl, MgCl and CaCl) solution were assessed using the bottle test technique at ambient and elevated temperatures (25 °C and 90 °C). The bottle test outcomes showed that EC-4 and EC-22 had better performance at the ambient conditions to demulsify the emulsions formed from distilled water with %DE of 85.71% and 28.57%, respectively, while EC-100 achieved 3.9% water removal owing to its high viscosity which inhibited its adsorption at the oil-water interface. At demulsification temperature (90 °C) under the emulsions from distilled water, the %DE of EC-4, EC-22, and EC-100 was 99.23%, 58.57%, and 42.85%, respectively. Seawater hastened the demulsification activities of these demulsifiers. Also, these demulsifiers demonstrated excellent demulsification in emulsions from various salts. The demulsification performance of the EC-4 demulsifier in the presence of any of these salts was approximately 98% while MgCl and CaCl accelerated the water/oil separation performance of EC-22 and EC-100 by promoting their diffusion and adsorption at the interface. Viscosity and shear stress measurements corroborated the results obtained from the bottle tests. Injection of EC demulsifiers led to a reduction in the viscosity and shear stress of the formed emulsion. Reduction in the shear stress and viscosity were highest in EC-4 and lowest in EC-100. Optical microscopic images of emulsion injected with EC-4 demulsifier were analyzed at various periods during viscosity measurements. Based on the optical images obtained at different durations, a demulsification mechanism describing the activity of the EC demulsifier was proposed.
高效的破乳剂对于快速破乳沥青稳定的原油乳状液非常重要。在这项工作中，我们评估了不同粘度的乙基纤维素（EC）破乳剂的破乳潜力-4 cp、22 cp 和 100 cp，分别命名为 EC-4、EC-22 和 EC-100。使用瓶试验技术在环境温度和升高的温度（25°C 和 90°C）下评估这些破乳剂从蒸馏水、海水和不同盐（NaCl、MgCl 和 CaCl）溶液制成的乳液中除去水的效率（DE）。瓶试验结果表明，EC-4 和 EC-22 在环境条件下对从蒸馏水形成的乳液具有更好的破乳性能，DE 分别为 85.71%和 28.57%，而 EC-100 由于其高粘度而仅去除 3.9%的水，这抑制了其在油水界面的吸附。在从蒸馏水形成的乳液的破乳温度（90°C）下，EC-4、EC-22 和 EC-100 的 DE 分别为 99.23%、58.57%和 42.85%。海水加速了这些破乳剂的破乳活性。此外，这些破乳剂在各种盐形成的乳液中表现出优异的破乳性能。在存在这些盐中的任何一种的情况下，EC-4 破乳剂的破乳性能约为 98%，而 MgCl 和 CaCl 通过促进其在界面的扩散和吸附，加速了 EC-22 和 EC-100 的油水分离性能。粘度和剪切应力测量结果与瓶试验结果一致。注入 EC 破乳剂导致形成的乳液的粘度和剪切应力降低。EC-4 导致的剪切应力和粘度降低最高，EC-100 导致的剪切应力和粘度降低最低。在粘度测量的不同时间点对注入 EC-4 破乳剂的乳液进行了光学显微镜图像分析。根据在不同时间段获得的光学图像，提出了一种描述 EC 破乳剂活性的破乳机制。
