If you're frustrated by frequently losing battery power in your laptop computer, digital camera or portable music player, then take heart: A better source of "juice" is in the works. Chemists at Arizona State University in Tempe have created a tiny hydrogen-gas generator that they say can be developed into a compact fuel cell package that can power these and other electronic devices -- from three to five times longer than conventional batteries of the same size and weight.
The generator uses a special solution containing borohydride, an alkaline compound that has an unusually high capacity for storing hydrogen, a key element that is used by fuel cells to generate electricity. In laboratory studies, a prototype fuel cell made from this generator was used to provide sustained power to light bulbs, radios and DVD players, the researchers say.
The fuel cell system can be packaged in containers of the same size and weight as conventional batteries and is recharged by refilling a fuel cartridge, they say. Research on these battery replacement fuel cells, which they claim are safer for the environment than regular batteries, was described today at the 232nd national meeting of the American Chemical Society.
"We're trying to maximize the usable hydrogen storage capacity of borohydride in order to make this fuel cell power source last longer," says study leader Don Gervasio, Ph.D., a chemist at the University's Biodesign Institute, Center for Applied NanoBioScience. "That could lead to the longest lasting power source ever produced for portable electronics."
One of the challenges in fuel cell development is finding hydrogen-rich compounds for the fuel source. Many different hydrogen sources have been explored for use in fuel cells, including metal hydride "sponges" and liquids such as gasoline, methanol, ethanol and even vegetable oil.
Recently, borohydride has shown promise as a safe, energy-dense hydrogen storage solution. Unlike the other fuel sources, borohydride works at room temperature and does not require high temperatures in order to liberate hydrogen, Gervasio says.
Gervasio and his associates are developing novel chemical additives to increase the useful hydrogen storage capacity of the borohydride solution by as much as two to three times that of simple aqueous sodium borohydride solutions that are currently being explored for fuel cell development. These additives prevent the solution from solidifying, which could potentially clog or damage the hydrogen generator and cause it to fail.
In developing the prototype fuel cell system, the researchers housed the solution in a tiny generator containing a metal catalyst composed of ruthenium metal. In the presence of the catalyst, the borohydride in the water-based solution reacts with water to form hydrogen gas.
The gas leaves the hydrogen generator by moving across a special membrane separating the generator from the fuel cell component. The hydrogen gas then combines with oxygen inside the fuel cell to generate water and electricity, which can then be used to power the portable electronic device. Commercialization of a practical version of this fuel cell could take as many as three to five years, Gervasio says.
Contact: Michael Bernstein m_bernstein@acs.org 415-978-3532 (San Francisco, CA, Sept. 10-14, 2006) 202-872-4400 (Washington, DC) American Chemical Society
http://www.newstarget.com/020961.html
Monday, April 30, 2007
Plastic circuitry breakthrough may revolutionize electronics industry
(NewsTarget) Researchers from the University of Cambridge's Cavendish Laboratory have a chance to revolutionize the electronics industry if they can develop plastic semiconductors.
The idea is to replace the silicon wafers in standard microchips with layers or circuitry on plastic substrates. While the concept of plastic semiconductors may seem like a pipe dream, Cambridge-based startup Plastic Logic has been talking about commercializing the technology since 2000. The company is putting money where it's mouth is, too, as it has more than $100 million worth of investment funds for a factory that it plans to open in Dresden, Germany.
The technology has "tremendous potential," said Morry Marshall, vice-president for strategic technologies at Phoenix semiconductor research group Semico, adding that it was a "breakthrough that is waiting to happen."
The final product should be a plastic sheet roughly the same size as a piece of A4 sized paper, being produced at a rate of about 2.2 million a year. They will be composed of polyethylene terephthalate -- the same type of plastic used to make soft drink bottles -- and initially supplied to other companies as the basis for pieces of "electronic paper," which can display the pages of thousands of books.
We hope to make it as easy to carry around large amounts of written information using devices based on our technology as it is now to have easy access to large amounts of music using an iPod or MP3 player," said Hermann Hauser, one of Plastic Logic's founders and a Cavendish Laboratory alumnus.
The proposed plastic semiconductors will have one disadvantage compared to traditional silicon-based substrates: There is between 5 and 10 micrometers (1 micrometer is 1 millionth of a meter) between adjacent circuitry lines in the plastic semiconductors, whereas the same space in traditional semiconductors is measured in nanometers (1 nanometer is a billionth of a meter). However, Plastic Logic Chief Executive Officer John Mills said that they are developing plastic circuits with only 60 nanometers between adjacent circuitry lines.
If they could be made smaller, plastic microchips could be used for tasks for which it would not be cost-effective to employ silicon microchips. For example, a toy could have a surface where it could display its own instruction manual.
"Plastic electronics could lead to a fundamental revolution in the way the electronics industry evolves", said Mr Hauser, who also said he would not be surprised if Plastic Logic's chief scientist Henning Sirringhaus was awarded the Nobel Prize for his work in the field.
The Cavendish Laboratory has been lauded for it's discoveries during the past 136 years, including the genetic building blocks known as DNA and the electron.
http://www.newstarget.com/021424.html
The idea is to replace the silicon wafers in standard microchips with layers or circuitry on plastic substrates. While the concept of plastic semiconductors may seem like a pipe dream, Cambridge-based startup Plastic Logic has been talking about commercializing the technology since 2000. The company is putting money where it's mouth is, too, as it has more than $100 million worth of investment funds for a factory that it plans to open in Dresden, Germany.
The technology has "tremendous potential," said Morry Marshall, vice-president for strategic technologies at Phoenix semiconductor research group Semico, adding that it was a "breakthrough that is waiting to happen."
The final product should be a plastic sheet roughly the same size as a piece of A4 sized paper, being produced at a rate of about 2.2 million a year. They will be composed of polyethylene terephthalate -- the same type of plastic used to make soft drink bottles -- and initially supplied to other companies as the basis for pieces of "electronic paper," which can display the pages of thousands of books.
We hope to make it as easy to carry around large amounts of written information using devices based on our technology as it is now to have easy access to large amounts of music using an iPod or MP3 player," said Hermann Hauser, one of Plastic Logic's founders and a Cavendish Laboratory alumnus.
The proposed plastic semiconductors will have one disadvantage compared to traditional silicon-based substrates: There is between 5 and 10 micrometers (1 micrometer is 1 millionth of a meter) between adjacent circuitry lines in the plastic semiconductors, whereas the same space in traditional semiconductors is measured in nanometers (1 nanometer is a billionth of a meter). However, Plastic Logic Chief Executive Officer John Mills said that they are developing plastic circuits with only 60 nanometers between adjacent circuitry lines.
If they could be made smaller, plastic microchips could be used for tasks for which it would not be cost-effective to employ silicon microchips. For example, a toy could have a surface where it could display its own instruction manual.
"Plastic electronics could lead to a fundamental revolution in the way the electronics industry evolves", said Mr Hauser, who also said he would not be surprised if Plastic Logic's chief scientist Henning Sirringhaus was awarded the Nobel Prize for his work in the field.
The Cavendish Laboratory has been lauded for it's discoveries during the past 136 years, including the genetic building blocks known as DNA and the electron.
http://www.newstarget.com/021424.html
When old electronics meet their end, much ends up becoming toxic waste in China
(NewsTarget) Old computers and other used-up appliances are creating polluted environments in Asia, the final resting place for much of the world's electronic goods, reports the China Daily newspaper.
Known as "e-waste," more than 75 percent of televisions, computers and other home electronics discarded by the developed world end up bound for Asia. Up to 90 percent of the old electronics goes to China, according to the Beijing-based Science and Technology Daily, the official newspaper of China's Ministry of Science and Technology.
However, only 10 percent of the electronics that go to China are recycled for reuse. The rest gets burned, destroyed or otherwise reduced to poisonous end-products.
Inside computers and other electronics are gold, copper and other reusable precious metals. This makes the 90 percent of discarded electronics not recycled a viable enterprise for people looking to extract those precious metals. However, many of these "electronics harvesters" use simple and environmentally unfriendly processes to get the metals out, such as putting the machines through acid baths.
The result is that lead, mercury and other chemicals are released into the atmosphere – through toxic gasses – and put into lakes and rivers through wastewater systems. The harvesters are burning the plastic cases, melting lead-based monitor glass and simply tossing out the undesirable by-products of precious metal extraction.
In some cities that are hotspots for the metal extraction business, pollution levels are much higher than American or European standards.
In the Guiyu area, an agricultural sector in south China that many e-processers have set up shop, the groundwater became so contaminated that drinking water had to be brought in from an area 18 miles away, according to a 2001 report from the Seattle-based toxic trade watchdog Basel Action Network.
Sediment samples from the area showed that the groundwater had so much lead in it that it would have been considered 212 times more toxified than acceptable standards if it came from Europe's Rhine River.
"Tin was found at levels 152 times the EPA threshold. Chromium in one sample was at levels 1,338 times the EPA threshold level," the report added.
A major source of this e-waste are unsuspecting good Samaritans in America thinking they are helping the environment: Much of the old electronics donated by people and businesses for recycling in the U.S. instead gets exported into the world market.
"Informed recycling industry sources estimate that between 50 to 80 percent of the e-waste collected for recycling in the western U.S. are not recycled domestically," according to the BAN report.
From there, the supply market takes over, and often metal extraction companies win.
The supply market of old electronics sways in favor of these shops because they often offer higher prices for the goods than recycling outfits can.
The supply is good, too: the volume of e-waste from the United States is "estimated at 5 to 7 million tons," the report said.
In China alone – excluding the e-waste that is brought into the country – "about 150 million television sets, washing machines, refrigerators, air-conditioners and computers are discarded every year in China," the China Daily reported, using statistics from the China Home Electronics Association.
For the American market, the BAN report from 2001 posited that e-waste numbers would rise by 2006 thanks to the proliferation of High-Definition Television – flat-screen TVs – obsolescing old television technology, and the fact that most computers bought today are replacements for an old one that must be thrown out.
The world market for e-waste is one that is mostly unregulated, but a limited number of other countries are involved. Outside of China, other countries in the metal extraction business include India and Pakistan. The Middle Eastern country of Dubai is another major collector of discarded electronics, but it acts as a middleman: most of what it receives is re-exported out to China and other countries.
http://www.newstarget.com/021578.html
Known as "e-waste," more than 75 percent of televisions, computers and other home electronics discarded by the developed world end up bound for Asia. Up to 90 percent of the old electronics goes to China, according to the Beijing-based Science and Technology Daily, the official newspaper of China's Ministry of Science and Technology.
However, only 10 percent of the electronics that go to China are recycled for reuse. The rest gets burned, destroyed or otherwise reduced to poisonous end-products.
Inside computers and other electronics are gold, copper and other reusable precious metals. This makes the 90 percent of discarded electronics not recycled a viable enterprise for people looking to extract those precious metals. However, many of these "electronics harvesters" use simple and environmentally unfriendly processes to get the metals out, such as putting the machines through acid baths.
The result is that lead, mercury and other chemicals are released into the atmosphere – through toxic gasses – and put into lakes and rivers through wastewater systems. The harvesters are burning the plastic cases, melting lead-based monitor glass and simply tossing out the undesirable by-products of precious metal extraction.
In some cities that are hotspots for the metal extraction business, pollution levels are much higher than American or European standards.
In the Guiyu area, an agricultural sector in south China that many e-processers have set up shop, the groundwater became so contaminated that drinking water had to be brought in from an area 18 miles away, according to a 2001 report from the Seattle-based toxic trade watchdog Basel Action Network.
Sediment samples from the area showed that the groundwater had so much lead in it that it would have been considered 212 times more toxified than acceptable standards if it came from Europe's Rhine River.
"Tin was found at levels 152 times the EPA threshold. Chromium in one sample was at levels 1,338 times the EPA threshold level," the report added.
A major source of this e-waste are unsuspecting good Samaritans in America thinking they are helping the environment: Much of the old electronics donated by people and businesses for recycling in the U.S. instead gets exported into the world market.
"Informed recycling industry sources estimate that between 50 to 80 percent of the e-waste collected for recycling in the western U.S. are not recycled domestically," according to the BAN report.
From there, the supply market takes over, and often metal extraction companies win.
The supply market of old electronics sways in favor of these shops because they often offer higher prices for the goods than recycling outfits can.
The supply is good, too: the volume of e-waste from the United States is "estimated at 5 to 7 million tons," the report said.
In China alone – excluding the e-waste that is brought into the country – "about 150 million television sets, washing machines, refrigerators, air-conditioners and computers are discarded every year in China," the China Daily reported, using statistics from the China Home Electronics Association.
For the American market, the BAN report from 2001 posited that e-waste numbers would rise by 2006 thanks to the proliferation of High-Definition Television – flat-screen TVs – obsolescing old television technology, and the fact that most computers bought today are replacements for an old one that must be thrown out.
The world market for e-waste is one that is mostly unregulated, but a limited number of other countries are involved. Outside of China, other countries in the metal extraction business include India and Pakistan. The Middle Eastern country of Dubai is another major collector of discarded electronics, but it acts as a middleman: most of what it receives is re-exported out to China and other countries.
http://www.newstarget.com/021578.html
Subscribe to:
Posts (Atom)