Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Water leads to chemical that gunks up biofuels production


Study shows water trips up key chemical reactions that turn plants into fuels, provides scientific principles that can speed up biofuel development

Trying to understand the chemistry that turns plant material into the same energy-rich gasoline and diesel we put in our vehicles, researchers have discovered that water in the conversion process helps form an impurity which, in turn, slows down key chemical reactions. The study, which was reported online at the Journal of the American Chemical Society in July, can help improve processes that produce biofuels from plants.

Planting roots

Bio-oil (right) is produced from biomass (left) through a process called fast pyrolysis.

The study examines the conversion of bio-oil, produced from biomass such as wood chips or grasses, into transportation fuels. Researchers used computer simulations to explore what happens to a common bio-oil byproduct. Water, everywhere during biofuels production, turns the byproduct into an impurity that disrupts and blocks the reactions that lead to biofuels. The results apply not only to water but to related liquids in bio-oil such as alcohols and certain acids.

The study provides a thorough view of the byproduct phenol reacting with catalysts. Catalysts are what chemists use to speed up the reactions that convert plants into fuels, reactions that occurred deep in the Earth over millions of years and gave us the fossil fuels we use today.

"We are getting to the heart of the fundamentals of biofuels catalysis," said co-author Roger Rousseau, a scientist at the Department of Energy's Pacific Northwest National Laboratory. "The work tells us that the impurity is unavoidable and we need to make sure it does not build up enough to interfere. Although this is a very fundamental issue, it points out for us what types of things we can do to help extend the lifetime of the catalysts we are using to make bio-oil."

Grass To Gasoline

To make plant matter into products that come from petroleum — gasoline and plastics — biofuels chemists need to understand every step of the process. To make biofuels, researchers rapidly heat up plant matter in a process called pyrolysis. They then use catalysts to convert the pyrolysis oil into transportation fuels.

The chemistry that occurs leads to the production of precursors to fuels and a byproduct called phenol. Phenol itself isn't too much of a problem in fuels, but it sits in the vat of chemicals and water that are undergoing a variety of reactions and gets converted into molecules called ketones.

Troublesome ketones will link up with others like them and form long chains that gunk up the catalysts and interfere with important reactions. Researchers at PNNL wanted to know the molecular details on how phenol converts to ketone. Ultimately, they discovered, it's not the catalyst's fault.

Catalyst in the Computer

While some ideas existed for how this happens, the team used computers to simulate phenol interacting with catalysts and water to see step-by-step what is going on. To explore water's role in the reaction, they also simulated the same reactions in a vacuum, which puts everything but the solid catalyst in vapor form. They performed these simulations using resources in EMSL, DOE's Environmental Molecular Sciences Laboratory at PNNL.

In the simulations, the catalyst is essentially a piece of metal, either nickel or platinum. The phenol molecules and water molecules randomly bounce or land on the metal surface where bonds break and reform between atoms within molecules by shifting electrons around. In this way, a phenol might transform into a ketone.

The team found that the presence of water dramatically upped the speed with which the final conversion to a ketone happened. In addition, water also affected how the metal catalyst carried its electrons, which in turn affected how well it catalyzed the reaction between phenol and hydrogen atoms that settle on the catalyst's surface.

"I was surprised at the role liquid plays in the reactivity of the metal catalyst," said PNNL's Yeohoon Yoon, a co-author on the study. "We know a lot about these reactions in the gas phase, but almost nothing in the liquid. The principles we've learned can be applied to other catalyst-driven reactions. They will make working in the complex system of real catalysts making real biofuels easier."

And that's the next step. PNNL colleagues at the Bioproducts, Sciences & Engineering Laboratory, a facility located on the Washington State University Tri-Cities campus where PNNL and WSU researchers collaborate, will use this work to guide development of pyrolysis oil transformation into biofuels.

The researchers also presented this work at the American Chemical Society's Annual Meeting in San Francisco on Aug. 12.

This work was supported by the Department of Energy Offices of Science and Energy Efficiency and Renewable Energy.

Reference: Yeohoon Yoon, Roger Rousseau, Robert S. Weber, Donghai Mei, and Johannes A. Lercher. First-principles Study of Phenol Hydrogenation on Pt and Ni Catalysts in Aqueous Phase, J. Am. Chem. Soc., July 2, 2014, DOI: 10.1021/ja501592y.

Tags: Energy, Fundamental Science, Computational Science, EMSL, Biomass, Renewable Energy, Biofuel, Green Energy, Energy Production, Chemistry, Catalysis, Supercomputer, Software

EMSL, the Environmental Molecular Sciences Laboratory, is a national scientific user facility sponsored by the Department of Energy's Office of Science.  Located at Pacific Northwest National Laboratory in Richland, Wash., EMSL offers an open, collaborative environment for scientific discovery to researchers around the world. Its integrated computational and experimental resources enable researchers to realize important scientific insights and create new technologies. Follow EMSL on Facebook, LinkedIn and Twitter.

Interdisciplinary teams at Pacific Northwest National Laboratory address many of America's most pressing issues in energy, the environment and national security through advances in basic and applied science. Founded in 1965, PNNL employs 4,300 staff and has an annual budget of about $950 million. It is managed by Battelle for the U.S. Department of Energy’s Office of Science. As the single largest supporter of basic research in the physical sciences in the United States, the Office of Science is working to address some of the most pressing challenges of our time. For more information on PNNL, visit the PNNL News Center, or follow PNNL on Facebook, Google+, LinkedIn and Twitter.

Mary Beckman | Eurek Alert!

Further reports about: Chemical Energy Environmental Laboratory Molecular PNNL Phenol Science Sciences Water fuels

More articles from Life Sciences:

nachricht Peering into cell structures where neurodiseases emerge
26.11.2015 | University of Delaware

nachricht How a genetic locus protects adult blood-forming stem cells
26.11.2015 | Stowers Institute for Medical Research

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Climate study finds evidence of global shift in the 1980s

Planet Earth experienced a global climate shift in the late 1980s on an unprecedented scale, fuelled by anthropogenic warming and a volcanic eruption, according to new research published this week.

Scientists say that a major step change, or ‘regime shift’, in the Earth’s biophysical systems, from the upper atmosphere to the depths of the ocean and from...

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...

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

How a genetic locus protects adult blood-forming stem cells

26.11.2015 | Life Sciences

Stanford technology makes metal wires on solar cells nearly invisible to light

26.11.2015 | Power and Electrical Engineering

Peering into cell structures where neurodiseases emerge

26.11.2015 | Life Sciences

More VideoLinks >>>