Saving energy, hiking pipeline oil flow

A strong electric field applied to a section of the Keystone pipeline can smooth oil flow and yield significant pump energy savings.
By Gregory Hale, ISSSource April 10, 2015

Traditionally, pipeline oil ends up heated over several miles in order to reduce the oil’s thickness (which is also known as viscosity), but this requires a large amount of energy and counter-productively increases turbulence within the flow.

In 2006, Rongjia Tao of Temple University in Pennsylvania proposed a more efficient way of improving flow rates by applying an electric field to the oil. The idea is to electrically align particles within the crude oil, which reduces viscosity and turbulence.

To test this, Tao collaborated with energy company Save The World Air, Inc. to develop an Applied Oil Technology (AOT) device that links to oil pipelines and produces an electric field along the direction of the oil flow.

Trials on oil pipelines in Wyoming and China found crude oil particles form short chains in an electric field. These chains reduce viscosity in the direction of flow to a minimum. At the same time the viscosity perpendicular to the flow increases, which helps suppress turbulence in the overall flow.

Last summer Tao and his colleagues also successfully tested the AOT device on a section of the Keystone pipeline near Wichita, Kansas.

"People were amazed at the energy savings when we first tested this device. They didn’t initially understand the physics," said Tao. "A second test with an independent company was arranged and found the same thing." Tests on a section of the Keystone pipeline found the same flow rate could occur with a 75% reduction of pump power from 2.8 MW to 0.7 MW, thanks to the AOT device. The device itself uses 720W.

Once aligned, the oil retained its low viscosity and turbulence for more than 11 hours before returning to its original viscosity. But the process is repeatable and Tao and his colleagues envision AOT stations spaced along a pipeline, significantly reducing the energy necessary to transport oil.

Gregory Hale is the editor and founder of Industrial Safety and Security Source (, a news and information website covering safety and security issues in the manufacturing automation sector. This content originally appeared on ISSSource. Edited by Joy Chang, Digital Project Manager, CFE Media,