“Corn belongs in the kitchen, not in biogas facilities” – objections like this can be heard more and more frequently. They are protesting against the fermentation of foodstuffs in biogas plants that generate electricity and heat.
One thing the opponents are afraid of is that generating electricity in this way will cause food prices to escalate. In collaboration with several small and medium-sized enterprises, research scientists at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden have developed the first-ever biogas plant that works entirely without edible raw materials.
“In our pilot plant, we exclusively use agricultural waste such as corn stalks – that is, the corn plants without the cobs. This allows us to generate 30 percent more biogas than in conventional facilities,” says IKTS head of department Dr. Michael Stelter. Until now, biogas plants have only been able to process a certain proportion of waste material, as this tends to be more difficult to convert into biogas than pure cereal crops or corn, for instance.
This is not the only advantage: The time for which the decomposing waste material, or silage, is stored in the plant can be reduced by 50 to 70 percent. Biomass is usually kept in the fermenter, building up biogas, for 80 days. Thanks to the right kind of pre-treatment, this only takes about 30 days in the new plant. “Corn stalks contain cellulose which cannot be directly fermented. But in our plant, the cellulose is broken down by enzymes before the silage ferments,” Stelter explains.
The researchers have also optimized the conversion of biogas into electricity. They divert the gas into a high-temperature fuel cell with an electrical efficiency of 40 to 55 percent. By comparison, the gas engine normally used for this purpose only achieves an average efficiency of 38 percent. What is more, the fuel cell operates at 850 degrees Celsius. The heat can be used directly for heating or fed into the district heating network. If the electrical and thermal efficiency are added up, the fuel cell has an overall efficiency of up to 85 percent.
The overall efficiency of the combustion engine is usually around 38 percent because its heat is very difficult to harness. The researchers have already built a pilot plant with an electricity output of 1.5 kilowatts, enough to cover the needs of a family home. The researchers will present the concept of the biogas plant at the Hannover-Messe on April 20 to 24 (Hall 13, Stand E20). In the next phases of the project, the scientists and their industrial partners plan to gradually scale up the biogas plant to two megawatts.
Dr. Michael Stelter | EurekAlert!
Researchers take next step toward fusion energy
16.11.2017 | Texas A&M University
Desert solar to fuel centuries of air travel
16.11.2017 | SolarPACES
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...
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...
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....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
17.11.2017 | Physics and Astronomy
17.11.2017 | Health and Medicine
17.11.2017 | Studies and Analyses