Controlling Nonpolar Colloidal Asphaltene Aggregation by Electrostatic Repulsion

详细信息    查看全文

• 作者：Sara M. Hashmi ; Abbas Firoozabadi
• 刊名：Energy & Fuels
• 出版年：2012
• 出版时间：July 19, 2012
• 年：2012
• 卷：26
• 期：7
• 页码：4438-4444
• 全文大小：324K
• 年卷期：v.26,no.7(July 19, 2012)
• ISSN：1520-5029

文摘

While aromatic chemicals are applied to petroleum oil systems to thermodynamically prevent asphaltene precipitation, amphiphilic dispersants can truncate the precipitation process and create stable suspensions of asphaltene colloids in the submicrometer size range. Bulk sedimentation and dynamic light scattering have shown that stabilizing dispersants inhibit colloidal asphaltene aggregation at approximately the same concentration as is needed to effectively slow bulk sedimentation. At the same time, these same types of dispersants can alter the electrostatic properties of colloidal asphaltenes in nonpolar suspensions. While electrostatic stabilization has been linked to aggregation dynamics in several types of colloidal systems, both aqueous and nonpolar, the complete linkage between electrostatic interactions and aggregation inhibition has yet to be shown in colloidal asphaltene suspensions. In this work, we present dynamic light scattering and electrophoresis measurements in colloidal asphaltene suspensions, using three different petroleum fluids and a dispersant which truncates asphaltene precipitation and colloidal aggregation by enabling uniform electrostatic charging at the colloidal asphaltene surface.