Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New reactor puts hydrogen from renewable fuels within reach

13.02.2004


The first reactor capable of producing hydrogen from a renewable fuel source--ethanol--efficiently enough to hold economic potential has been invented by University of Minnesota engineers. When coupled with a hydrogen fuel cell, the unit--small enough to hold in your hand--could generate one kilowatt of power, almost enough to supply an average home, the researchers said. The technology is poised to remove the major stumbling block to the "hydrogen economy": no free hydrogen exists, except what is made at high cost from fossil fuels. The work will be published in the Feb. 13 issue of Science.



The researchers see an early use for their invention in remote areas, where the installation of new power lines is not feasible. People could buy ethanol and use it to power small hydrogen fuel cells in their basements. The process could also be extended to biodiesel fuels, the researchers said. Its benefits include reducing dependence on imported fuels, reducing carbon dioxide emissions (because the carbon dioxide produced by the reaction is stored in the next year’s corn crop) and boosting rural economies.

Hydrogen is now produced exclusively by a process called steam reforming, which requires very high temperatures and large furnaces--in other words, a huge input of energy. It’s unsuitable for any application except large-scale refineries, said Lanny Schmidt, Regents Professor of Chemical Engineering, who led the effort. Working with him were scientist Gregg Deluga, first author of the Science paper, and graduate student James Salge. All three are in the university’s department of chemical engineering and materials science.


"The hydrogen economy means cars and electricity powered by hydrogen," said Schmidt. "But hydrogen is hard to come by. You can’t pipe it long distances. There are a few hydrogen fueling stations, but they strip hydrogen from methane--natural gas--on site. It’s expensive, and because it uses fossil fuels, it increases carbon dioxide emissions, so this is only a short-term solution until renewable hydrogen is available."

Ethanol is easy to transport and relatively nontoxic. It is already being produced from corn and used in car engines. But if it were used instead to produce hydrogen for a fuel cell, the whole process would be nearly three times as efficient. That is, a bushel of corn would yield three times as much power if its energy were channeled into hydrogen fuel cells rather than burned along with gasoline.

"We can potentially capture 50 percent of the energy stored in sugar [in corn], whereas converting the sugar to ethanol and burning the ethanol in a car would harvest only 20 percent of the energy in sugar," said Schmidt. "Ethanol in car engines is burned with 20 percent efficiency, but if you used ethanol to make hydrogen for a fuel cell, you would get 60 percent efficiency."

The difference, Deluga explained, is due in large part to the need to remove all the water from ethanol before it can be put in an automobile gas tank--and the last drops of water are the hardest to remove. But the new process doesn’t require pure ethanol; in fact, it strips hydrogen from both ethanol and water, yielding a hydrogen bonus.

The invention rests on two innovations: a catalyst based on the metals rhodium and ceria, and an automotive fuel injector that vaporizes and mixes the ethanol-water fuel. The vaporized fuel mixture is injected into a tube that contains a porous plug made from rhodium and ceria. The fuel mixture passes through the plug and emerges as a mixture of hydrogen, carbon dioxide and minor products. The reaction takes only 50 milliseconds and eliminates the flames and soot that commonly accompany ethanol combustion.

In a typical ethanol-water fuel mixture, one could ideally get five molecules of hydrogen for each molecule of ethanol. Reacting ethanol alone would yield three hydrogen molecules. So far, the Schmidt team has harvested four hydrogen molecules per ethanol molecule.

"We’re confident we can improve this technology to increase the yield of hydrogen and use it to power a workable fuel cell," said Salge.


The work was supported by the University of Minnesota’s Initiative on Renewable Energy and the Environment, the National Science Foundation and the U.S. Department of Energy.

Embargoed by Science until 2 p.m. Eastern time (1 p.m. Central) Thursday, Feb. 12. For a copy of the paper, call 202-326-6440 or e-mail scipak@aaas.org.

Contacts:
Lanny Schmidt, 612-625-9391
Gregg Deluga, 612-625-6083
James Salge, 612-625-6073
Deane Morrison, University News Service, 612-624-2346 (Feb. 9-10 and after Feb. 15)
Patty Mattern, University News Service, 612-624-0214 (Feb. 11-15)

Deane Morrison | EurekAlert!
Further information:
http://www.umn.edu/

More articles from Power and Electrical Engineering:

nachricht Researchers measure near-perfect performance in low-cost semiconductors
18.03.2019 | Stanford University

nachricht Robot arms with the flexibility of an elephant’s trunk
18.03.2019 | Universität des Saarlandes

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Revealing the secret of the vacuum for the first time

New research group at the University of Jena combines theory and experiment to demonstrate for the first time certain physical processes in a quantum vacuum

For most people, a vacuum is an empty space. Quantum physics, on the other hand, assumes that even in this lowest-energy state, particles and antiparticles...

Im Focus: Sussex scientists one step closer to a clock that could replace GPS and Galileo

Physicists in the EPic Lab at University of Sussex make crucial development in global race to develop a portable atomic clock

Scientists in the Emergent Photonics Lab (EPic Lab) at the University of Sussex have made a breakthrough to a crucial element of an atomic clock - devices...

Im Focus: Sensing shakes

A new way to sense earthquakes could help improve early warning systems

Every year earthquakes worldwide claim hundreds or even thousands of lives. Forewarning allows people to head for safety and a matter of seconds could spell...

Im Focus: A thermo-sensor for magnetic bits

New concept for energy-efficient data processing technology

Scientists of the Department of Physics at the University of Hamburg, Germany, detected the magnetic states of atoms on a surface using only heat. The...

Im Focus: The moiré patterns of three layers change the electronic properties of graphene

Combining an atomically thin graphene and a boron nitride layer at a slightly rotated angle changes their electrical properties. Physicists at the University of Basel have now shown for the first time the combination with a third layer can result in new material properties also in a three-layer sandwich of carbon and boron nitride. This significantly increases the number of potential synthetic materials, report the researchers in the scientific journal Nano Letters.

Last year, researchers in the US caused a big stir when they showed that rotating two stacked graphene layers by a “magical” angle of 1.1 degrees turns...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Researchers measure near-perfect performance in low-cost semiconductors

18.03.2019 | Power and Electrical Engineering

Nanocrystal 'factory' could revolutionize quantum dot manufacturing

18.03.2019 | Materials Sciences

Long-distance quantum information exchange -- success at the nanoscale

18.03.2019 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>