Inexpensive material offers solution for ocean oil spills

Super-absorbent material could mitigate environmental impacts of spills, while allowing recovered oil to be reused

Michael Chung, professor of materials science at Penn State, holds a solid chunk of oil that is able to be reused. Chung and his team developed a patented material called i-Petrogel that completely absorbs spilled oil and transforms it into a usable product. Credit: Liam Jackson / Penn StateAll Rights Reserved.

UNIVERSITY PARK, Pa. — A super-absorbent material developed by Penn State scientists could dramatically reduce the environmental impact of oil spills on oceans and allow recovered oil to be refined normally.

The synthetic material, called i-Petrogel, absorbs more than 40 times its weight in crude oil, and effectively stops the oil from spreading after a spill, according to the researchers.

The researchers designed the material to maximize its ability to absorb oil, but not water. The oil collected can then be refined by regular means and reused, further reducing environmental waste and pollution associated with other collection methods.

A super-absorbent material developed by Penn State scientists could dramatically reduce the environmental impact of oil spills on oceans and allow recovered oil to be refined normally. 

"If the recovered oil can't be reused, it needs to be dumped somewhere. It's useless," said T.C. Mike Chung, professor of materials science and engineering. "That's why we developed a technology that is comprehensive. i-Petrogel is a polymer made from oil. It's a pure hydrocarbon."

The researchers created i-Petrogel by mixing two polyolefin polymers in the laboratory, and then scaled up the product for use in large-scale field tests. Because the product is an oil-based polymer, it is strongly bonded to oil and also does not need to be removed before refining.

The team members recently reported their findings in Sustainable Chemistry and Engineering.

Two gallons of fresh Alaska North Slope oil is released in the figure at left. The oil is treated with i-Petrogel in the figure at right. Credit: Penn StateCreative Commons

"We already know what kind of polymers can absorb oil," Chung said. "Some oil is very thick and takes a long time to absorb, so we blended two polymers to provide structure with high surface area. It's a microporous structure. If you look inside there are many small holes. This morphological structure allows the viscous oil to diffuse inside, allowing for more oil to absorb through the surfaces."

The blend of two polymers — an interpenetrating polymer network of hard and soft polymers — can be optimized for different oil viscosities and other factors. The researchers  have three U.S. patents on this work, and i-Petrogel is undergoing steps to become commercially produced.

During the field tests, researchers found the new polymer absorbed more than 40 times its weight in Alaska North Slope oil, double the capacity of its predecessor, Petrogel, also developed by the same Penn State researchers. The product takes on a gel-like consistency as it absorbs oil and remains at the surface. It can be readily removed using skimmers already used in clean-ups.

Previous techniques used to quell disasters like the Deepwater Horizon incident in 2010 recovered about 10 percent of the oil spilled, and the recovered oil was unusable. That generated about 80,000 tons of solid waste from soiled booms, and additional liquid oil waste mixed with salt water as responders struggled to contain the estimated 200 million gallons of spilled oil.

Oil that has been treated with i-Petrogel is gathered using a skimmer. This oil can immediately be transferred to the refinery without any further steps. Credit: Penn StateCreative Commons

BP used dispersants and underwater oil-eating microorganisms to mitigate damage from the worst oil spill in history, yet roughly 60 percent was never accounted for. For Arctic incidents such as the Exxon-Valdez spill in 1989, Chung said fewer recovery options exist because microorganisms are ineffective in that colder climate. Because of the lack of methods for dealing with cold-water spills, researchers tailored i-Petrogel for Alaskan crude oil, where 20 percent of all U.S. oil was extracted at the time of the Exxon-Valdez spill.

Chung said i-Petrogel works in any climate and pays for itself in recovered oil alone. For example, one barrel of crude oil could be recovered using less than 8 pounds of i-Petrogel, which costs $2 per pound to manufacture. Using today's crude oil prices, it would cost $16 to recover $85 worth of oil.

The U.S. Department of the Interior's Bureau of Safety and Environmental Enforcement funded this research.

Last Updated February 01, 2019