Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Mixing Processes Could Increase the Impact of Biofuel Spills on Aquatic Environments

Ethanol, a component of biofuel made from plants such as corn, is blended with gas in many parts of the country, but has significantly different fluid properties than pure gasoline.

A group of researchers from the University of Michigan wondered how ethanol-based fuels would spread in the event of a large aquatic spill. They found that ethanol-based liquids mix actively with water, very different from how pure gasoline interacts with water and potentially more dangerous to aquatic life.

The scientists will present their results, which could impact the response guidelines for ethanol fuel-based spills, at the American Physical Society’s (APS) Division of Fluid Dynamics (DFD) meeting, held Nov. 18 – 20, in San Diego, Calif.

“Ethanol/gasoline blends are often presented as more environmentally benign than pure gasoline, but there is, in fact, little scientific research into the effects these blends could have on the health of surface waters,” says Avery Demond, an associate professor and director of the Environmental and Water Resources Engineering program at the University of Michigan, and one of the researchers who is working on the project. Some reports written for the State of California include methods for calculating the spread of ethanol into water based on a passive diffusion/dispersion process, notes Demond, but the method was not based on strong scientific evidence of how the two fluids interact.

The Michigan researchers were motivated to fill some of the knowledge gaps. They experimented by filling a tank with water, covering the water with a plate, and pouring ethanol mixtures on top. The plate was then pulled away and the researchers recorded videos of the two fluids as they began to mix. The videos showed flow patterns called convection cells forming at the interface of the ethanol mixture and water. The mixing of the two fluids produced heat that changed the density and viscosity of the fluid, giving rise to circulation currents. In contrast, pure gasoline is essentially insoluble in water and primarily remains on the surface where it vaporizes into the air.

“The mixing behavior [of ethanol-based fuel mixtures and water], from my perspective, is very unusual,” says Demond. “I’ve never seen anything quite like it and it certainly is not passive the way that modeling guidelines suggest.” Aline Cotel, also an associate professor at the University of Michigan and another member of the research team, will present videos of the unusual mixing patterns at the conference.

As a next step, the researchers would like to study how different ethanol mixtures vaporize, helping them to determine how much of a spill would end up mixed into the water and how much would volatilize into the air. Although ethanol is biodegradable, in high concentrations it can be toxic to fish and other aquatic life. The ethanol in ethanol/gasoline blends might also transport some of the carcinogenic components of gasoline into the water during the mixing process.

“We can’t make statements about the environmental impact of ethanol before we’ve more fully investigated its potential effects on surface water quality in the event of a spill,” note the researchers.

Ultimately, they hope their work will help answer outstanding questions about how ethanol mixes with water, giving scientists and policy makers a firmer grasp of the potential risks of ethanol-based biofuels.

Presentation: “Characterization of Mixing Between Water and Biofuels,” is at 9:31 a.m. on Tuesday, Nov. 20, in room 23A.


The 65th Annual Meeting of the American Physical Society (APS) Division of Fluid Dynamics will take place from November 18-20, 2012, in San Diego, Calif. It will bring together researchers from across the globe to address some of the most important questions in modern astronomy, engineering, alternative energy, biology, and medicine. All meeting information, including directions to the Convention Center, is at:
Main Meeting Web Site:
Searchable Abstracts:
Directions and Maps:
Credentialed full-time journalists and professional freelance journalists working on assignment for major publications or media outlets are invited to attend the conference free of charge. If you are a reporter and would like to attend, please contact Charles Blue (, 301-209-3091).
A media-support desk will be available. Press announcements and other news will be available in the Virtual Press Room (see below).
The APS Division of Fluid Dynamics Virtual Press Room will be launched in mid-November and will feature news releases, graphics, videos, and other information to aid in covering the meeting on site and remotely. See:
Every year, the APS Division of Fluid Dynamics hosts posters and videos that show evocative images and graphics from either computational or experimental studies of flow phenomena. The outstanding entries are selected for their artistic content, originality, and ability to convey information. They will be honored during the meeting, placed on display at the 2013 APS March Meeting, and appear in the annual Gallery of Fluid Motion article in the American Institute of Physics' journal, Physics of Fluids.

Selected entries from the Gallery of Fluid Motion will be hosted as part of the Fluid Dynamics Virtual Press Room. In mid-November, when the Virtual Press Room is launched, another announcement will be sent out.

This release was prepared by the American Institute of Physics (AIP) on behalf of the American Physical Society’s (APS) Division of Fluid Dynamics (DFD).

The Division of Fluid Dynamics of the American Physical Society (APS) exists for the advancement and diffusion of knowledge of the physics of fluids with special emphasis on the dynamical theories of the liquid, plastic and gaseous states of matter under all conditions of temperature and pressure. See:

Charles Blue | Newswise Science News
Further information:

More articles from Ecology, The Environment and Conservation:

nachricht Taking a molecular approach to conserving freshwater biodiversity
09.11.2015 | Universiti Putra Malaysia (UPM)

nachricht Faster digestion in kangaroos reduces methane emissions
05.11.2015 | Universität Zürich

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Innovative Photovoltaics – from the Lab to the Façade

Fraunhofer ISE Demonstrates New Cell and Module Technologies on its Outer Building Façade

The Fraunhofer Institute for Solar Energy Systems ISE has installed 70 photovoltaic modules on the outer façade of one of its lab buildings. The modules were...

Im Focus: Lactate for Brain Energy

Nerve cells cover their high energy demand with glucose and lactate. Scientists of the University of Zurich now provide new support for this. They show for the first time in the intact mouse brain evidence for an exchange of lactate between different brain cells. With this study they were able to confirm a 20-year old hypothesis.

In comparison to other organs, the human brain has the highest energy requirements. The supply of energy for nerve cells and the particular role of lactic acid...

Im Focus: Laser process simulation available as app for first time

In laser material processing, the simulation of processes has made great strides over the past few years. Today, the software can predict relatively well what will happen on the workpiece. Unfortunately, it is also highly complex and requires a lot of computing time. Thanks to clever simplification, experts from Fraunhofer ILT are now able to offer the first-ever simulation software that calculates processes in real time and also runs on tablet computers and smartphones. The fast software enables users to do without expensive experiments and to find optimum process parameters even more effectively.

Before now, the reliable simulation of laser processes was a job for experts. Armed with sophisticated software packages and after many hours on computer...

Im Focus: Quantum Simulation: A Better Understanding of Magnetism

Heidelberg physicists use ultracold atoms to imitate the behaviour of electrons in a solid

Researchers at Heidelberg University have devised a new way to study the phenomenon of magnetism. Using ultracold atoms at near absolute zero, they prepared a...

Im Focus: Climate Change: Warm water is mixing up life in the Arctic

AWI researchers’ unique 15-year observation series reveals how sensitive marine ecosystems in polar regions are to change

The warming of arctic waters in the wake of climate change is likely to produce radical changes in the marine habitats of the High North. This is indicated by...

All Focus news of the innovation-report >>>



Event News

Fraunhofer’s Urban Futures Conference: 2 days in the city of the future

25.11.2015 | Event News

Gluten oder nicht Gluten? Überempfindlichkeit auf Weizen kann unterschiedliche Ursachen haben

17.11.2015 | Event News

Art Collection Deutsche Börse zeigt Ausstellung „Traces of Disorder“

21.10.2015 | Event News

Latest News

Harnessing a peptide holds promise for increasing crop yields without more fertilizer

25.11.2015 | Agricultural and Forestry Science

Earth's magnetic field is not about to flip

25.11.2015 | Earth Sciences

Tracking down the 'missing' carbon from the Martian atmosphere

25.11.2015 | Physics and Astronomy

More VideoLinks >>>