Separation of Water from High pH Water-in-Heavy Oil Emulsions Using Low Pressure CO2

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• 作者：Mingzhe Dong ; Houjian Gong ; Wei Tian ; Yajun Li
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2014
• 出版时间：August 6, 2014
• 年：2014
• 卷：53
• 期：31
• 页码：12216-12223
• 全文大小：399K
• ISSN：1520-5045

文摘

In this study, a demulsification treatment process for high pH water-in-oil (W/O) emulsions, using low pressure CO₂ and demulsifier, with optimized temperature and mixing time is designed. The efficacy of different acids, including HCl and CH₃COOH, are also examined using this method, to be compared with the results obtained with CO₂ gas. Both the demulsifier and CO₂ are indispensable in this demulsification treatment process. The demulsification efficiency increases rapidly with the increase of demulsifier concentration when the initial concentration is lower than 120 mg/L. With the further increase of concentration, the demulsification efficiency can reach 83% and remain constant. Meanwhile, the demulsification efficiency increases with the increase of CO₂ pressure. It is found that the optimum CO₂ pressure is between 50 and 200 kPa, with a mixing time of 65鈥?25 min, where a demulsification efficiency of approximately 80鈥?0% can be achieved. Settling under elevated temperature (70 掳C), after CO₂ demulsification, is also investigated; the results indicate that heating does not improve the demulsification efficiency if the pressure is over 500 kPa. Under the same conditions, CO₂ shows better demulsification efficiency than that obtained by HCl and CH₃COOH. At a pH of approximately 7.0鈥?.7, the emulsion is the least stable, and the maximum demulsification efficiency is obtained.