But today's processes are notoriously inefficient. In a new paper,* researchers at the National Institute of Standards and Technology (NIST) have detailed some of the most fundamental processes involved in extracting sugars from biomass, the first step in producing ethanol by fermentation. Their findings should help engineers to improve their process designs in order to extract the maximum amount of fuel from a given measure of biomass.
Most of the ethanol produced in the United States is created by fermenting the sugars and starch found in corn. The capability to convert inedible plants and agricultural waste into usable sources for ethanol production will help to supplement alternatives to fossil fuels while reducing the diversion of food crops to energy uses.
Glucose can be extracted from two substances found in most plants: cellulose, the long molecule chains that comprise the cell walls of green plants, and its flimsier cell-wall counterpart, hemicellulose. The extracted glucose is then easily converted by fermentation to ethanol. NIST researchers, in collaboration with the National Renewable Energy Laboratory in Golden, Colo., have defined the theoretical limits of reactions important to cleaving, or breaking apart, cellulose and hemicellulose to produce glucose. They also determined that the energy needed to rupture these key bonds is a constant value for each molecular bond that is broken during the cleavage reactions.
According to Yadu Tewari, Brian Lang and Robert Goldberg, chemists at NIST and co-authors of the paper, cellulose and hemicellulose both present problems to would-be ethanol producers.
"Cellulose and hemicellulose are recalcitrant," Goldberg says. "They don't want to break down. It takes a long time for wood to rot. It even takes termites a long time to break wood down, and they're pretty good at it. Ethanol producers face the same problem. Because of the way these molecules are arranged, it's difficult to get access to the reactive centers in wood and other biomass. What we have done is to study some of the most basic reactions associated with the breakdown of these materials."
With enzymes to speed the reactions, the team used calorimetry and chromatography to measure the thermodynamic property values of several reactions associated with the breakdown of cellulosic and hemicellulosic substances. Because process design and bioengineering benefit from the availability of these values, the data obtained in this investigation represent a "small but significant step toward maximizing the efficiency of biomass utilization," Tewari says.
Antimicrobial substances identified in Komodo dragon blood
23.02.2017 | American Chemical Society
New Mechanisms of Gene Inactivation may prevent Aging and Cancer
23.02.2017 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
23.02.2017 | Physics and Astronomy
23.02.2017 | Earth Sciences
23.02.2017 | Life Sciences