Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Energy wasted grinding switchgrass smaller to improve flowability

13.04.2010
Biofuels processors who mill switchgrass into fine bits to help its flowability should be able to save time, energy and money by not doing so, a Purdue University study shows.

Switchgrass can be used in a number of biofuel applications, but moving it - especially feeding it into boilers - can be problematic, said Klein Ileleji, an assistant professor of agricultural and biological engineering.

While corn and soybeans are round and spherical, switchgrass is shaped more like matchsticks, causing pieces to interlock and disrupt its ability to flow. Those blockages cost time and can be dangerous for those tasked with breaking the clog, he said.

"In any facility ¨l in a power plant or in a processing facility ¨l when you have a blockage, it's a processing nightmare," said Ileleji, whose findings are in the current issue of the journal Transactions of the ASABE.

Ileleji compared circularity, roundness and aspect ratio for corn, soybean and switchgrass that had been hammermilled to three different sizes. Aspect ratio, which has the greatest effect on the ability of switchgrass to flow, is the ratio of a switchgrass particle's length to its width.

Conventional wisdom held that grinding switchgrass into smaller pieces would bring its aspect ratio closer to that of corn and soybeans, which have ratios close to 1 and no problems with flowability.

"Switchgrass is not a good flowable feedstock. You would think grinding it smaller would help," Ileleji said. "But grinding does not necessarily change the morphological characteristics in switchgrass that are important for flow."

Ileleji's testing showed that hammermilling - one of the most common grinding techniques, which beats and breaks biomass until it is small enough to pass through screens - breaks switchgrass in a way that keeps its aspect ratio about the same no matter the size. Unless the switchgrass is milled into a powder, those high aspect ratios would keep causing switchgrass to interlock and clog in bulk flow.

Ileleji said processors could save money with the information because they can stop hammermilling switchgrass when it fits through a 6.4 mm screen, the largest Ileleji tested.

"Grinding consumes a lot of energy. It is one of the highest energy costs in a processing facility," Ileleji said. "It's better to grind switchgrass through a 6.4 mm screen than to use more energy to grind through a smaller screen expecting that its handling characteristics would be improved dramatically."

Ileleji said he would study flow behavior of switchgrass through hoppers to try to find ways to keep it from creating blockages. Duke Energy and the Purdue Energy Center funded his research, which is part of his doctoral student Cedric Ogden's research on the flow mechanics of switchgrass bulk solid in hoppers under gravity discharge.

Abstract on the research in this release is available at: http://www.purdue.edu/newsroom/research/2010/100412IelejiMorphology.html

Brian Wallheimer | EurekAlert!
Further information:
http://www.purdue.edu

More articles from Agricultural and Forestry Science:

nachricht Light green plants save nitrogen without sacrificing photosynthetic efficiency
21.11.2017 | Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign

nachricht Filling intercropping info gap
16.11.2017 | American Society of Agronomy

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

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

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Underwater acoustic localization of marine mammals and vehicles

23.11.2017 | Information Technology

Enhancing the quantum sensing capabilities of diamond

23.11.2017 | Physics and Astronomy

Meadows beat out shrubs when it comes to storing carbon

23.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>