Deumulsifier-free Slop-oil Emulsion Destabilization (PPT)

摘要

Slop-oil consists of water-in-oil emulsions with solids, normally treated by adding demulsifiers and dehydrating thermal, electrostatically and gravity assisted. Results of tests conducted on three Venezuelan slop-oils are presented. Main aim is to show the destabilizing ability of the electrostatic field in the absence of demulsifiers, indicating that the field interacts with the stabilized interface and promotes the emulsion breaking instead of just a coalescence acceleration effect. Behavior was microscopically inspected and some batch arrangements were tested. Finally, a continuous system using both AC-DC current and cylindrical and plane electrode geometry was built, followed by batch centrifugation. Microscope evaluation after electrostatic treatment shows, for all cases, a drop- size substantial increase. Different residence times were used being field strength only limited by the onset of percolation (short-circuits). A destabilization factor was used to assess increase of water in droplets greater than a given size. The better separations were obtained when using DC current, cylindrical electrodes and low residence time. Additional tests were conducted incorporating a coalescer-media, indicating that the use of oil-wetted materials were more effective. Although bulk coalescence was not always achieved due to cooling before centrifugation, results demonstrate that an important destabilization effect can be reached by proper using the electrical field and/or adding coalescer-media. This findings can conduct to an hybrid system were these features could be put together to a centrifugation system (maybe a three-phase centrifuge) for separating this slop-oils with no chemical addition or at least with an important lowering of the required dosage.