Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Corn waste potentially more than ethanol

20.07.2006
After the corn harvest, whether for cattle feed or corn on the cob, farmers usually leave the stalks and stems in the field, but now, a team of Penn State researchers think corn stover can be used not only to manufacture ethanol, but to generate electricity directly.

"People are looking at using cellulose to make ethanol," says Dr. Bruce E. Logan, the Kappe Professor of Environmental Engineering. "You can make ethanol from exploded corn stover, but once you have the sugars, you can make electricity directly."

Logan's process uses a microbial fuel cell to convert organic material into electricity. Previous work has shown that these fuel cells can generate electricity from glucose and from municipal wastewater and that these cells can also directly generate hydrogen gas.

Corn stalks and leaves, amassing 250 million tons a year, make up a third of the total solid waste produced in the United States. Currently, 90 percent of corn stover is left unused in the field. Corn stover is about 70 percent cellulose or hemicellulose, complex carbohydrates that are locked in chains. A steam explosion process releases the organic sugars and other compounds in the corn waste and these compounds can be fed to microbial fuel cells.

The microbial fuel cells contain two electrodes and anaerobic bacteria – bacteria that do not need oxygen – that consume the sugars and other organic material and release electrons. These electrons travel to the anode and flow in a wire to the cathode, producing electrical current. The water in the fuel cell donates positive hydrogen atoms that combine with the electrons and oxygen to form water.

The microbial fuel cells were inoculated with domestic wastewater and a nutrient medium containing glucose, the researchers report in the journal Energy and Fuels. Once established, the bacteria colonies were fed the sugary organic liquid obtained from steam exploding of corn stover.

The researchers, who include Logan, Yi Zuo, Penn State graduate student in environmental engineering, and Pin-Ching Maness, senior scientist, National Renewable Energy Laboratory, report that "the conversion of organic matter to electricity, on the basis of biological oxygen demand removal, was relatively high with greater than 93 percent of the biological oxygen demand removed."

In essence, there is no organic matter left to cause problems when disposing of the remaining liquid because there is nothing left to oxidize. The process converts all the available energy to electricity. The electrical production is about one watt for every square meter of surface area at about 0.5 volts. A typical light bulb uses 60 watts. To increase wattage, the surface area needs to increase. To increase voltage, fuel cells can be linked in series.

"Producing electricity from steam exploded corn stover adds to the energy diversity of our portfolio," says Logan. "Electricity can be used to pump water uphill for later use, directly run light, heat and equipment or electrolyze water to create hydrogen."

The Penn State researcher and colleagues have also used microbial fuel cells and wastewater to produce hydrogen gas directly.

A'ndrea Elyse Messer | EurekAlert!
Further information:
http://www.psu.edu

More articles from Power and Electrical Engineering:

nachricht IHP presents the fastest silicon-based transistor in the world
05.12.2016 | IHP - Leibniz-Institut für innovative Mikroelektronik

nachricht High-precision magnetic field sensing
05.12.2016 | ETH Zurich

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: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

High-precision magnetic field sensing

05.12.2016 | Power and Electrical Engineering

Construction of practical quantum computers radically simplified

05.12.2016 | Information Technology

NASA's AIM observes early noctilucent ice clouds over Antarctica

05.12.2016 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>