Research Initiation: Direct Viscosity Enhancement of Dense Carbon Dioxide

这项研究的主要目的是通过溶解少量的化合物来诱导液体二氧化碳粘度的显着增加，这些化合物可能在液体相中聚集并形成长的大分子样结构。三种类型的化合物将使用一种新型的高压可视下降圆筒粘度计和高压PVT设备进行评估。各种油溶的非离子和半氟化表面活性剂将与少量的水一起溶解在二氧化碳中，试图形成长圆柱形的反胶束和微乳液。半氟烷烃是第二类候选化合物。最后，将三正丁基氟化锡和助溶剂引入液体二氧化碳中。在当前低粘度二氧化碳溶液导致旁路或窜流、采收率低的油藏中，增加二氧化碳的粘度对于开发驱替介质可能是有价值的。对表面活性剂在超临界流体中行为的了解也可能导致结合表面活性剂技术和超临界流体技术的新的分离和纯化工艺。

The primary objective of this proposed research is to induce a significant increase in the viscosity of liquid carbon dioxide by dissolving small amounts of chemical compounds which may aggregate in the fluid phase and form long macromolecule-like structures. Three types of compounds will be evaluated using a novel, high pressure, visual falling cylinder viscometer and a high pressure PVT apparatus. Various oil soluble nonionic and semi-fluorinated surfactants will be dissolved in carbon dioxide along with small amounts of water, in an attempt to form long, cylindrical reverse micelles and microemulsions. Semi-fluorinated alkanes constitute the second category of candidate compounds. Finally, tri-n-butyltin fluoride and a cosolvent will be introduced into the liquid carbon dioxide. Increasing the viscosity of carbon dioxide may be of value in developing displacement media in oil reservoirs where current low viscosity carbon dioxide solutions lead to by-passing or channeling and low recovery efficiencies. An understanding of surfactant behavior in supercritical fluids may also lead to new separation and purification processes combining surfactant technology and supercritical fluid technology.