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| Author | Topic: Alternative Energy |
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Breakthrough technology splits wate (Moderator) |
posted 12/4/04 12:35 AM
Thursday, December 02, 2004 commentary: Breakthrough technology splits water into clean fuels by harnessing solar power Source: http://www.sciencedaily.com/releases/2004/08/040825094820.htm Australian scientists predict that a revolutionary new way to harness the power of the sun to extract clean and almost unlimited energy supplies from water will be a reality within seven years. Using special titanium oxide ceramics that harvest sunlight and split water to produce hydrogen fuel, the researchers say it will then be a simple engineering exercise to make an energy-harvesting device with no moving parts and emitting no greenhouse gases or pollutants. It would be the cheapest, cleanest and most abundant energy source ever developed: the main by-products would be oxygen and water. "This is potentially huge, with a market the size of all the existing markets for coal, oil and gas combined," says Professor Janusz Nowotny, who with Professor Chris Sorrell is leading a solar hydrogen research project at the University of New South Wales (UNSW) Centre for Materials and Energy Conversion. The team is thought to be the most advanced in developing the cheap, light-sensitive materials that will be the basis of the technology. Sorrell says Australia is ideally placed to take advantage of the enormous potential of this new technology: "We have abundant sunlight, huge reserves of titanium and we're close to the burgeoning energy markets of the Asia-Pacific region. The results of the team's work will be presented in Sydney on 27 August to delegates from Japan, Germany, the United States and Australia at a one-day International Conference on Materials for Hydrogen Energy at UNSW. Both are frontrunners for the Nobel Prize in chemistry and are the laureates of the 2004 Japan Prize. Since the Japanese researchers' 1971 discoveries, science has made major advances in achieving one of the ultimate goals of science and technology -- the design of materials required to split water using solar light. http://www.newstarget.com/002633.html |
| Power of Pee Runs a Battery |
posted 8/17/05 1:04 AM
Power of Pee Runs a Battery Bjorn Carey LiveScience Staff Writer LiveScience.com Tue Aug 16,10:00 AM ET Scientists have developed a way to turn pee into electricity. And there's plenty were that came from, they point out. Cheap, disposable, and renewable, urine-powered batteries may be the perfect power source for disposable healthcare test kits called biochips, the researchers say. "We are striving to develop cheap, disposable credit card-sized biochips for disease detection," said battery developer Ki Bang Lee. "Our battery can be easily integrated into such devices, supplying electricity upon contact with biofluids such as urine." The research is detailed in the Aug. 15 issue of the Institute of Physics' Journal of Micromechanics and Microengineering. Scientists around the world are clamoring to design inexpensive biochips to quickly test for a variety of diseases. But no one has been able to make a similarly small and inexpensive power source. Lee and his team of researchers at Singapore's Institute of Bioengineering and Nanotechnology have tackled this problem by using the very substance being tested – urine – to power the test. To make the battery, Lee and his team soaked a piece of paper in copper chloride and then sandwiched it between strips of magnesium and copper. Then they laminated the credit card-sized unit between transparent plastic films. When a drop of urine is added to the copper chloride paper, a chemical reaction takes place and produces electricity, which is harnessed by the battery. A few drops will generate about 1.5 volts, the same as a AA battery. The battery needs to be developed further to make it commercially viable. "Our urine-activated battery would be integrated into biochip systems for healthcare diagnostic applications," Lee said. Lee and his team also found that they could alter the battery's performance – voltage, power, or duration – by adjusting the design or materials. The chemical composition of urine indicates a person's general health and is widely used in diagnostic tests. For instance, doctors measure the concentration of the sugar glucose to determine whether someone is diabetic. Lee predicts that one day people will be able to monitor their own health at home using biochips powered by this type of battery. "These fully-integrated biochip systems have a huge market potential," Lee said. http://news.yahoo.com/s/space/20050816/sc_space/powerofpeerunsabattery |
| Solar alchemy turns fumes back into fuels |
posted 10/7/06 5:26 AM
Solar alchemy turns fumes back into fuels 16 September 2006 NewScientist.com news service Rob Edwards IT IS the biggest contributor to climate change. Now chemists are hoping to convert carbon dioxide into a useful fuel, with a little help from the sun. If they succeed, it will be possible to recycle the greenhouse gas produced by burning fossil fuels. The work could also lead to a way for future Mars missions to generate fuel for their return journey from carbon dioxide in the planet's atmosphere. Chemists have long hoped to find a method of bringing the combustion of fuel full circle by turning CO2 back into useful hydrocarbons. Now researchers at the University of Messina in Italy have developed an electro-catalytic technique they say could do the job. "The conversion of CO2 to fuel is not a dream, but an effective possibility which requires further research," says team leader Gabriele Centi. The researchers chemically reduced CO2 to produce eight and nine-carbon hydrocarbons using a catalyst of particles of platinum and palladium confined in carbon nanotubes. These hydrocarbons can be made into petrol and diesel. To begin with, the researchers used sunlight plus a thin film of titanium dioxide to act as a photocatalyst to split water into oxygen gas plus protons and electrons. These are then carried off separately, via a proton membrane and wire respectively, before being combined with CO2 plus the nano-catalyst to produce the hydrocarbons. Although the nano-catalysts produced two or three times more hydrocarbons than a commercially available catalyst, the process converted only about 1 per cent of the CO2 at room temperature. Centi believes it will be possible to improve on that by using higher temperatures and a larger surface area of catalyst. It will also be necessary to boost the efficiency of the solar water-splitting, he says. With the right research, Centi believes that an efficient solar-powered reactor for converting CO2 into fuel could be available "within a decade". He presented his latest work, which is funded by the European Union, at a meeting of the American Chemical Society in San Francisco on 13 September. Other chemists reacted positively, but cautiously, to the findings. "It sounds feasible," says John Turner from the US National Renewable Energy Laboratory in Golden, Colorado. "The solar-to-hydrocarbon conversion efficiency is pretty small, but it sounds like they are just getting started." Ian Plumb, who researches water-splitting reactions at the Australian national research institute CSIRO Industrial Physics, says that unless the efficiency is improved it will be too expensive to implement. "But there is no doubt that what they are trying to achieve is very worthwhile." From issue 2569 of New Scientist magazine, 16 September 2006, page 30 http://www.newscientist.com/article/mg19125696.300?DCMP=NLC-nletter&nsref=mg19125696.300 |
| Biofuels Discovery Promises to End Dependence on Natural Gas |
posted 11/5/06 9:27 AM
Biofuels Discovery Promises to End Dependence on Natural Gas Researchers at the University of Minnesota have developed a new, carbon-neutral way to convert vegetable-based fuels to syngas, a breakthrough that could allow producers to power hydrogen fuel cells or create a replacement for America's dwindling supplies of natural gas, all without relying on fossil fuels. We've all had the experience of watching cooking oil smoke once a pan reaches a certain temperature—and suffered the indignity of having to scrub off the caked-on, carbonized gunk that results. A similar problem plagued researchers trying to convert biofuels: When heated, they clogged the pores of the catalyst used to transform them into syngas, which is a mixture of gases that include hydrogen, carbon monoxide and carbon dioxide. The breakthrough came with the perfection of a technique that heats fuel to a temperature so hot that the smoking reaction is bypassed, said Bradon Dreyer, a chemical engineering and materials science graduate student at the University of Michigan. Dreyer and his colleagues built a reactor capable of producing hydrogen from soybean oil, biodiesel or sugar water without any of the buildup that would have resulted from a conventional process. To get the reactor warmed up, the researchers ignited a mixture of methane and oxygen in order to bring the catalyst to a searing 1,000 degrees Fahrenheit. Addressing concerns about keeping the process carbon-neutral, Paul Dauenhauer, another graduate student working on the project, notes that while methane is a fossil fuel, there are other ways to heat the catalyst that don't involve burning petrochemicals. What's more, once the reaction is running, it's self-sustaining, and methane and oxygen are no longer required. A fuel injector like those used in a car atomized the biofuels into tiny droplets that landed on a hot rhodium-cerium catalyst, which converted the fuel to syngas. This reaction released energy and heated the catalyst. The heat and ratio of carbon and oxygen in the reaction kept the buildup from sticking to the catalyst. For each type of biofuel, nearly all the fuel was converted and about 70 percent of the hydrogen bound up in the fuel molecules was given off as gas, the researchers report in this week's Science. "We find we reach the theoretical maximum," says Dauenhauer. The whole reaction takes less than 50 milliseconds. "Faster means smaller," says Dreyer, who predicts that because of its speed, their reactor can be scaled down and remain efficient. Dreyer also notes that their reactor could work on other fuels, including used cooking oil. Best of all, no more carbon comes out of their system than went into it. http://tinyurl.com/ygn2qc |
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