Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Brown University chemists simplify biodiesel conversion

08.10.2010
Two chemists at Brown University have streamlined the conversion of waste vegetable oil into biodiesel, eliminating the need for corrosive chemicals to perform the reactions. Writing in the journal Organic & Biomolecular Chemistry, the chemists were able to pull off the waste vegetable oil-to-biodiesel conversion in a single reaction vessel using environmentally friendly catalysts and making the conversion six times faster than current methods.

As the United States seeks to lessen its reliance on foreign oil, biodiesel is expected to play a role. According to the National Renewable Energy Laboratory, a branch of the Department of Energy, biodiesel “represents a significant energy resource and could someday supply 3 percent to 5 percent of the distillate fuel market.”

One major obstacle to achieving that goal is figuring how to efficiently convert the abundant stocks of waste vegetable oil (oil used after cooking French fries, for example) into biodiesel fuel. Current techniques take time, are costly and are inefficient. Worse, the conversion requires the toxic chemicals sulfuric acid and either potassium hydroxide or sodium hydroxide.

That’s where Brown University chemist Jason Sello and postdoctoral researcher Aaron Socha come in. They write in the journal Organic & Biomolecular Chemistry that they were able to convert waste vegetable oil to biodiesel in a single reaction vessel using environmentally friendly catalysts. Their process is also six times faster than current methods for converting waste vegetable oil to biodiesel, so it consumes less energy.

“We wanted to develop an environmentally benign and technically simple way to convert waste vegetable oil into biodiesel,” said Sello, assistant professor of chemistry. “The production of energy at the expense of the environment is untenable and should be avoided at all costs.”

Waste vegetable oil is made up of triacylglycerols, free fatty acids, and water. The conventional way to convert waste vegetable oil into biodiesel requires two separate reactions. The first reaction turns the free fatty acids into biodiesel, but that conversion requires sulfuric acid. The second reaction converts the triacylglycerols into biodiesel, but that conversion requires sodium hydroxide or potassium hydroxide. Sodium hydroxide/potassium hydroxide and sulfuric acid are not compatible with each other, so the reactions must be carried out in separate vessels. That makes the process less efficient.

To find a better way, Sello and Socha went looking for catalysts that would be cheap, chemically stable and of limited toxicity. They settled on the metals bismuth triflate and scandium triflate, commonly used as catalysts in preparative organic chemistry. In addition, they performed the reactions using a microwave reactor instead of a conventional thermal heater. What they found was the new catalysts converted waste vegetable oil into biodiesel in about 20 minutes in the microwave reactor, whereas current reactions without catalysts using a conventional heater take two hours. While their microwave method needs a higher temperature to pull off the biodiesel conversion — 150 degrees Celsius versus 60 degrees Celsius under current methods — it uses less energy overall because the reaction time is much shorter.

The chemists also were able to perform the conversion in one reaction vessel, since the catalysts can promote both the reaction that converts free fatty acids into biodiesel and the reaction in which triacylgycerols are converted to biodiesel.

The team also reports that the catalysts in the free fatty acid conversion, which is the more challenging of the two reactions, could be recycled up to five times, while maintaining the capacity to promote a 97 percent reaction yield. The fact the catalysts can be recycled lowers their cost and environmental impact, the researchers said.

“While we have not yet proven the viability of our approach on an industrial scale,” Sello said, “we have identified very promising catalysts and reaction conditions that could, in principle, be used for large-scale conversion of waste vegetable oil into biodiesel in an enviornmentally sensitive manner.”

The research was funded by the National Science Foundation through a grant to Sello and an American Competitiveness in Chemistry award to Socha. Brown also supported the work through a R.B. Salomon award to Sello.

In a separate yet related paper, a team led by Brown chemistry professor Paul Williard has created a new technique to chart the progress of a reaction in which virgin oils are converted into biodiesel fuel.

The technique, called DOSY (for diffusion-ordered nuclear magnetic resonance spectroscopy), observes virgin oil molecules as they shrink in size and move faster in solution during the reaction. The reaction is complete when all of the molecules have been converted into smaller components known as fatty acid esters. These fatty acid esters are used as biodiesel fuel.

The results are published in the journal Energy & Fuels. The research was funded by the National Science Foundation. Contributing authors include Sello, Socha, Brown graduate students Gerald Kagan and Weibin Li, and lab technician Russell Hopson.

Richard Lewis | EurekAlert!
Further information:
http://www.brown.edu
http://news.brown.edu/pressreleases/2010/10/biodiesel

More articles from Life Sciences:

nachricht A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>