Electricity from strawFebruary 03, 2009Researchers have developed the first-ever biogas plant to run purely on waste instead of edible raw materials - transforming waste into valuable material. The plant generates 30 percent more biogas than its predecessors. A fuel cell efficiently converts the gas into electricity. "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. Fraunhofer-Gesellschaft |
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| Related Biogas Current Events and Biogas News Articles Waste could generate up to 7 percent of electricity in Spain Researchers from the University of Zaragoza (UNIZAR) have calculated the energy and economic potential of urban solid waste, sludge from water treatment plants and livestock slurry for generating electricity in Spain. Key issues for the future of wind energy The prestigious journal Energy Policy has recently reported two studies that highlight some key issues for the future of wind energy in Spain. Energy efficient sewage plants High-rate digestion with microfiltration is state-of-the-art in large sewage plants. It effectively removes accumulated sludge and produces biogas to generate energy. A study now reveals that even small plants can benefit from this process. Virtually engineering power plants Photovoltaic and wind energy plants, hydroelectric power stations and biogas plants supply energy without polluting the environment. However, they are complex to design and maintain. Virtual reality (VR) makes planning and operation easier. Microscopic manufacturers produce eco-friendly plastics Last year's energy crisis highlighted an unforseen by-product of the looming fuel shortages of the 21st century. Petroleum-based products such as plastics that society takes for granted but now requires to function will run out with the oil. Cow power could generate electricity for millions Converting livestock manure into a domestic renewable fuel source could generate enough electricity to meet up to three per cent of North America's entire consumption needs and lead to a significant reduction in greenhouse gas emissions (GHGs), according to US research published today. Biogas production is all in the mixing Engineers at Washington University in St. Louis, using an impressive array of imaging and tracking technologies, have determined the importance of mixing in anaerobic digesters for bioenergy production and animal and farm waste treatment. Methane from microbes: a fuel for the future Microbes could provide a clean, renewable energy source and use up carbon dioxide in the process, suggested Dr James Chong at a Science Media Centre press briefing today. More biogas, less sludge Germany has more than 10,000 sewage plants, using costly processes to treat household, industrial and restaurant waste water. The treated water is discharged back into river and lake systems. What remains is an organic / inorganic mixture of sludge. The issue is how to dispose of this residue. Up to now, sewage sludge has been used as an agricultural fertilizer, burned to produce energy or dumped on landfill sites. However, legislation prohibiting the use of landfill sites for the disposal of organic waste is to be introduced in Germany in 2005. The Fraunhofer Institute for Ceramic Technologies and Sintered Materials IKTS, working with the Ingenieurgesellschaft für Wasser und Entsorgung BSE Residues: anaerobic digestion saves 45 million euros a year The treatment of BSE residues through anaerobic digestion is, according to Quercus, the most efficient and fruitful way of resolving this environmental question. This is a biological process successfully put into practice in a national company, ITS Marques, and consists of the degradation of organic matter by microorganisms in the absence of oxygen. After being put in a closed receptacle (called a "digester"), the organic matter is transformed into gas by the existing microorganisms. Mostly made up of methane, that biogas is susceptible to being used in the production of renewable energy by electric generator. According to Quercus, this solution cost the Portuguese state nothing, seeing a More Biogas Current Events and Biogas News Articles |
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