When corn stover is processed to make cellulosic ethanol, everything is ground down and blended together. But a research team found that three distinct parts of the stover – the rind, pith and leaves – break down in different ways.
Michael Ladisch, a distinguished professor of agricultural and biological engineering and director of Purdue's Laboratory of Renewable Resources Engineering; Eduardo Ximenes, a Purdue research scientist in LORRE; and doctoral graduate student Meijuan Zeng are trying to determine if there is a better method to process corn stover and optimize efficiency.
Cellulosic ethanol is created by using enzymes to extract sugars from cellulosic feedstocks, such as corn stover, grasses and woods, and then fermenting and distilling those sugars into fuels.
"Today, researchers grind the parts together and treat it based on what's needed to get at the hardest part," Ximenes said. "We show that there are major differences in degradability among the tissues."
Stover's pith, the soft core that makes up more than half the weight of a corn stalk, is the easiest for enzymes to digest, according to the findings in two papers published in the journal Biotechnology and Bioengineering. Rind is the most difficult, while leaves fall in between. Significant amounts of lignin, the rigid compound in plant cell walls, make the cellulose resistant to hydrolosis, a process in which cellulose is broken down into sugars.
Ximenes said converting the rinds only adds about 20 percent more ethanol while requiring 10 times more enzymes, driving up the price of the process.
"Is that extra 20 percent worth the added cost?" asked Nathan Mosier, associate professor of agricultural and biological engineering and co-author of the study. "Because if there is a way to separate out pith, you could burn the leftover rinds to generate steam, creating energy needed to operate the plant."
Ladisch added that separating pieces of corn stover and treating them differently would be a new way of approaching cellulosic ethanol production.
"It uses existing conversion technology, but it enables us to think about a new way of getting the most from that technology," Ladisch said. "There is absolutely no reason a ligno-cellulosic non-food material such as corn stalk cannot be used to make ethanol if you understand the science."
Also involved in the research were Youngmi Kim, a Purdue research engineer; Wilfred Vermerris, an associate professor of agronomy at the University of Florida; Debra Sherman, director of the Purdue Life Science Microscopy Facility; Chia-Ping Huang, microscope technologist at the Life Sciences Microscopy Facility; and Bruce Dien, a chemical engineer with the Bioenergy Research Unit of the U.S. Department of Agriculture's Agricultural Research Service.
Ladisch and Ximenes said they would next work with colleagues to explore ways to improve the ability of enzymes to create sugars from cellulose and remove the compounds that inhibit those enzymes, as well as adapting the findings for other feedstocks such as switchgrass and wood.
Ladisch is chief technology officer at Mascoma, a renewable fuels company based in New Hampshire. He received no funding from the company for this research, which was funded by the U.S. Department of Energy, Purdue Agricultural Research Programs and a David Ross Fellowship.
Writer: Brian Wallheimer, 765-496-2050, firstname.lastname@example.orgSources: Michael Ladisch, 765-494-7022, email@example.com
Brian Wallheimer | EurekAlert!
Study shines light on brain cells that coordinate movement
26.06.2017 | University of Washington Health Sciences/UW Medicine
New insight into a central biological dogma on ion transport
26.06.2017 | Aarhus University
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
26.06.2017 | Life Sciences
26.06.2017 | Physics and Astronomy
26.06.2017 | Information Technology