200-Fold Boost in Fuel Cell Efficiency Advances ‘Personalized Energy Systems’
A new catalyst could help speed development of inexpensive home-brewed solar energy systems for powering homes and plug-in cars during the day (left) and for producing electricity from a fuel cell at night (right). (Credit: Patrick Gillooly/MIT)
The era of personalized energy systems — in which individual homes and small businesses produce their own energy for heating, cooling and powering cars — took another step toward reality today as scientists reported discovery of a powerful new catalyst that is a key element in such a system. They described the advance, which could help free homes and businesses from dependence on the electric company and the corner gasoline station, at the 240th National Meeting of the American Chemical Society, being held here this week.
“Our goal is to make each home its own power station,” said study leader Daniel Nocera, Ph.D. “We’re working toward development of ‘personalized’ energy units that can be manufactured, distributed and installed inexpensively. There certainly are major obstacles to be overcome — existing fuel cells and solar cells must be improved, for instance. Nevertheless, one can envision villages in India and Africa not long from now purchasing an affordable basic system.” (more…)
Hydrogen, Possible Fuel of the Future, Causes Metal to Break
A researcher installs an enviromental chamber in the special laboratory in which metals' susceptibility to stress corrosion can be tested. (Credit: Fraunhofer IWM)
Most likely, there is hardly a soul that cannot recall K.I.T.T. – the legendary talking supercar from the US television series “Knight Rider”. A hydrogen turbo motor fuels the fantasy vehicle and propels it on the chase for the bad guys at over 300 miles an hour. In the future, cars may be equipped with hydrogen propulsion not just in the movies, but in real life as well.
In the transportation and energy sectors, hydrogen is viewed as an eventual alternative to the raw materials of fossil-fuel power, such as coal, petroleum and natural gas. However, for metals like steel, aluminum and magnesium - which are commonly used in automotive and energy technology – hydrogen is not quite ideal. It can make these metals brittle; the ductility of the metal becomes reduced. Its durability deteriorates. This can lead to sudden failure of parts and components. Beside the fuel tank itself, or parts of the fuel cell, but ordinary components like ball bearings could also be affected. These are found not only in the car, but also in almost all industrial machinery.
This lightest of the chemical elements permeates the raw materials of which the vehicle is made not only when filling the tank, but also through various manufacturing processes. Hydrogen can infiltrate the metal lattice through corrosion, or during chromium-plating of car parts. Infiltration may likewise occur during welding, milling or pressing. The result is always the same: the material may tear or break without warning. (more…)
Waste Chip Fat Fuels Hydrogen Economy
Don’t pour that dirty fat from the frier down the sink – it could be used to make the fuel of the future.
Hydrogen has been tipped as a cleaner, greener alternative to fossil fuels. But scientists have struggled to find a way to make it that doesn’t consume vast amounts of energy, use up scarce natural resources, or spew out high levels of greenhouse gas.
Researchers at the University of Leeds have now found an energy-efficient way to make hydrogen out of used vegetable oils discarded by restaurants, takeaways and pubs. Not only does the process generate some of the energy needed to make the hydrogen gas itself, it is also essentially carbon-neutral.
“We are working towards a vision of the hydrogen economy,” said Dr Valerie Dupont, who is leading the Leeds-based project. “Hydrogen –based fuel could potentially be used to run our cars or even drive larger scale power plants, generating the electricity we need to light our buildings, run our kettles and fridges, and power our computers. But hydrogen does not occur naturally, it has to be made. With this process, we can do that in a sustainable way by recycling waste materials, such as used cooking oil.” (more…)
Scientists Discover Inexpensive Metal Catalyst for Generating Hydrogen from Water
From left, Jeffrey Long, Christopher Chang and Hemamala Karunadasa have discovered an inexpensive metal that can generate hydrogen from neutral water, even if it is dirty, and can operate in sea water. (Photo by Roy Kaltschmidt, Berkeley Lab Public Affairs)
Hydrogen would command a key role in future renewable energy technologies, experts agree, if a relatively cheap, efficient and carbon-neutral means of producing it can be developed. An important step towards this elusive goal has been taken by a team of researchers with the U.S. Department of Energy’s (DOE) Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California, Berkeley. The team has discovered an inexpensive metal catalyst that can effectively generate hydrogen gas from water.
“Our new proton reduction catalyst is based on a molybdenum-oxo metal complex that is about 70 times cheaper than platinum, today’s most widely used metal catalyst for splitting the water molecule,” said Hemamala Karunadasa, one of the co-discoverers of this complex. “In addition, our catalyst does not require organic additives, and can operate in neutral water, even if it is dirty, and can operate in sea water, the most abundant source of hydrogen on earth and a natural electrolyte. These qualities make our catalyst ideal for renewable energy and sustainable chemistry.” (more…)
Viruses Harnessed to Create Hydrogen Fuel from Water
Angela Belcher, the Germeshausen Professor of Materials Science and Engineering and Biological Engineering, demonstrates a virus-templated catalyst solution used in harnessing energy from water. Photo: Dominick Reuter
A team of MIT researchers has found a novel way to mimic the process by which plants use the power of sunlight to split water and make chemical fuel to power their growth. In this case, the team used a modified virus as a kind of biological scaffold that can assemble the nanoscale components needed to split a water molecule into hydrogen and oxygen atoms.
Splitting water is one way to solve the basic problem of solar energy: It’s only available when the sun shines. By using sunlight to make hydrogen from water, the hydrogen can then be stored and used at any time to generate electricity using a fuel cell, or to make liquid fuels (or be used directly) for cars and trucks.
Other researchers have made systems that use electricity, which can be provided by solar panels, to split water molecules, but the new biologically based system skips the intermediate steps and uses sunlight to power the reaction directly. The advance is described in a paper published on April 11 in Nature Nanotechnology.
The team, led by Angela Belcher, the Germeshausen Professor of Materials Science and Engineering and Biological Engineering, engineered a common, harmless bacterial virus called M13 so that it would attract and bind with molecules of a catalyst (the team used iridium oxide) and a biological pigment (zinc porphyrins). The viruses became wire-like devices that could very efficiently split the oxygen from water molecules.
Over time, however, the virus-wires would clump together and lose their effectiveness, so the researchers added an extra step: encapsulating them in a microgel matrix, so they maintained their uniform arrangement and kept their stability and efficiency. (more…)
Layered Graphene Sheets Could Solve Hydrogen Storage Issues
A graphene-oxide framework (GOF), formed of layers of graphene connected by boron-carboxylic “pillars.” GOFs such as this one are just beginning to be explored as a potential storage medium for hydrogen and other gases. (NIST)
Graphene—carbon formed into sheets a single atom thick—now appears to be a promising base material for capturing hydrogen, according to recent research* at the National Institute of Standards and Technology (NIST) and the University of Pennsylvania. The findings suggest stacks of graphene layers could potentially store hydrogen safely for use in fuel cells and other applications.
Graphene has become something of a celebrity material in recent years due to its conductive, thermal and optical properties, which could make it useful in a range of sensors and semiconductor devices. The material does not store hydrogen well in its original form, according to a team of scientists studying it at the NIST Center for Neutron Research. But if oxidized graphene sheets are stacked atop one another like the decks of a multilevel parking lot, connected by molecules that both link the layers to one another and maintain space between them, the resulting graphene-oxide framework (GOF) can accumulate hydrogen in greater quantities.
Inspired to create GOFs by the metal-organic frameworks that are also under scrutiny for hydrogen storage, the team is just beginning to uncover the new structures’ properties. “No one else has ever made GOFs, to the best of our knowledge,” says NIST theorist Taner Yildirim. “What we have found so far, though, indicates GOFs can hold at least a hundred times more hydrogen molecules than ordinary graphene oxide does. The easy synthesis, low cost and non-toxicity of graphene make this material a promising candidate for gas storage applications.” (more…)
Scavenging Energy Waste to Turn Water Into Hydrogen Fuel
UW-Madison geologist and crystal specialist Huifang Xu.
Materials scientists at the University of Wisconsin-Madison have designed a way to harvest small amounts of waste energy and harness them to turn water into usable hydrogen fuel.
The process is simple, efficient and recycles otherwise-wasted energy into a useable form.
“This study provides a simple and cost-effective technology for direct water splitting that may generate hydrogen fuels by scavenging energy wastes such as noise or stray vibrations from the environment,” the authors write in a new paper, published March 2 in the Journal of Physical Chemistry Letters. “This new discovery may have potential implications in solving the challenging energy and environmental issues that we are facing today and in the future.”
The researchers, led by UW-Madison geologist and crystal specialist Huifang Xu, grew nanocrystals of two common crystals, zinc oxide and barium titanate, and placed them in water. When pulsed with ultrasonic vibrations, the nanofibers flexed and catalyzed a chemical reaction to split the water molecules into hydrogen and oxygen.
When the fibers bend, asymmetries in their crystal structures generate positive and negative charges and create an electrical potential. This phenomenon, called the piezoelectric effect, has been well known in certain crystals for more than a century and is the driving force behind quartz clocks and other applications. (more…)
Generating Clean Hydrogen Fuel With Sunlight
Emory University chemists have developed the most potent homogeneous catalyst known for water oxidation, considered a crucial component for generating clean hydrogen fuel using only water and sunlight. (Photo by Benjamin Yin, Emory University)
Emory University chemists have developed the most potent homogeneous catalyst known for water oxidation, considered a crucial component for generating clean hydrogen fuel using only water and sunlight. The breakthrough, published March 11 in the journal Science, was made in collaboration with the Paris Institute of Molecular Chemistry.
The fastest, carbon-free molecular water oxidation catalyst (WOC) to date “has really upped the standard from the other known homogeneous WOCs,” said Emory inorganic chemist Craig Hill, whose lab led the effort. “It’s like a home run compared to a base hit.”
In order to be viable, a WOC needs selectivity, stability and speed. Homogeneity is also a desired trait, since it boosts efficiency and makes the WOC easer to study and optimize. The new WOC has all of these qualities, and it is based on the cheap and abundant element cobalt, adding to its potential to help solar energy go mainstream.
Benjamin Yin, an undergraduate student in Hill’s lab, is the lead author on the Science paper. Emory chemists who are co-authors include Hill, Yurii Gueletii, Jamal Musaev, Zhen Luo and Ken Hardcastle. The U.S. Department of Energy funded the work.
The WOC research is a component of the Emory Bio-inspired Renewable Energy Center, which aims to mimic natural processes such as photosynthesis to generate clean fuel. The next step involves incorporating the WOC into a solar-driven, water-splitting system. (more…)
Applied Electric Field Can Significantly Improve Hydrogen Storage Properties
This image illustrates that an applied electric field polarizes hydrogen molecules and the substrate, inducing hydrogen absorption with good thermodynamics and kinetics. Image courtesy of Qian Wang, Ph.D./VCU.
An international team of researchers has identified a new theoretical approach that may one day make the synthesis of hydrogen fuel storage materials less complicated and improve the thermodynamics and reversibility of the system.
Many researchers have their sights set on hydrogen as an alternative energy source to fossil fuels such as oil, natural gas and coal that contain carbon, pollute the environment and contribute to global warming. Known to be the most abundant element in the universe, hydrogen is considered an ideal energy carrier – not to mention that it’s clean, environmentally friendly and non-toxic. However, it has been difficult to find materials that can efficiently and safely store and release it with fast kinetics under ambient temperature and pressure.
The team of researchers from Virginia Commonwealth University ; Peking University in Beijing; and the Chinese Academy of Science in Shanghai; have developed a process using an electric field that can significantly improve how hydrogen fuel is stored and released. (more…)
Hydrogen-Powered Ion Tiger Sets 26-Hour Flight Endurance Record
The Naval Research Laboratory’s Ion Tiger, a hydrogen-powered fuel cell unmanned air vehicle (UAV), has flown 26 hours and 1 minute carrying a 5-pound payload, setting another unofficial flight endurance record for a fuel-cell powered flight. The test flight took place on November 16th through 17th.
The electric fuel cell propulsion system onboard the Ion Tiger has the low noise and signature of a battery-powered UAV, while taking advantage of hydrogen, a high-energy fuel. Fuel cells create an electrical current when they convert hydrogen and oxygen into water and heat. The 550 Watt (0.75 horsepower) fuel cell onboard the Ion Tiger has about four times the efficiency of a
comparable internal combustion engine and the system provides seven times the energy in the equivalent weight of batteries. The Ion Tiger weighs approximately 37 pounds and carries a 4- to 5-pound payload.
The Ion Tiger fuel cell system development team is led by NRL and includes Protonex Technology Corporation, HyperComp Engineering, and Arcturus UAV. The program is sponsored by the Office of Naval Research. (more…)
New Hydrogen-Storage Method Discovered
This schematic shows the structure of the new material, Xe(H2)7. Freely rotating hydrogen molecules (red dumbbells) surround xenon atoms (yellow). (Nature Chemistry)
Scientists at the Carnegie Institution have found for the first time that high pressure can be used to make a unique hydrogen-storage material. The discovery paves the way for an entirely new way to approach the hydrogen-storage problem. The researchers found that the normally unreactive, noble gas xenon combines with molecular hydrogen (H2) under pressure to form a previously unknown solid with unusual bonding chemistry. The experiments are the first time these elements have been combined to form a stable compound. The discovery debuts a new family of materials, which could boost new hydrogen technologies. The paper is published in the November 22, 2009, advanced online publication of Nature Chemistry.
Xenon has some intriguing properties, including its use as an anesthesia, its ability to preserve biological tissues, and its employment in lighting. Xenon is a noble gas, which means that it does not typically react with other elements. (more…)
Researchers Turn Algae Into High-Temperature Hydrogen Source
This image shows the process by which Photosystem I in thermophilic blue-green algae can be catalyzed by platinum to produce a sustainable source of hydrogen. The system was highlighted in a paper by University of Tennessee, Knoxville research Barry Bruce, et al. in Nature Nanotechnology. (Barry D. Bruce/University of Tennessee, Knoxville)
Platinum-catalyzed photosynthetic process creates high-yield sustainable source of hydrogen.
In the quest to make hydrogen as a clean alternative fuel source, researchers have been stymied about how to create usable hydrogen that is clean and sustainable without relying on an intensive, high-energy process that outweighs the benefits of not using petroleum to power vehicles.
New findings from a team of researchers from the University of Tennessee, Knoxville, and Oak Ridge National Laboratory, however, show that photosynthesis – the process by which plants regenerate using energy from the sun – may function as that clean, sustainable source of hydrogen. (more…)
Solving Hydrogen Storage Limit to Power Green Cars
Hydrogen fuel, because its only byproduct is steam, should be the ultimate in green alternatives to fossil fuels, but it hasn’t delivered on its promise yet because of one enormous stumbling block, storage. Now a team of chemical engineers at the University of Massachusetts Amherst has developed a computational model that shows that carbon nanotubes may offer a surprising solution. Results are presented in the current online issue of the journal, Applied Physics Letters.
“If this works as we expect, it’s perhaps no longer science fiction to hope for a briefcase-sized hydrogen battery to run a bus or car,” says UMass Amherst chemical engineering professor Dimitrios Maroudas. “Hydrogen storage has been a huge problem in the energy field for the past 10 years because no one has been able to demonstrate a truly viable storage medium. We’ve shown that it’s possible to achieve hydrogen storage capacity up to 8 percent by weight using carbon nanotubes. This is an outstanding level, higher by 1 percent than the 2010 United States Department of Energy target for on-board hydrogen storage systems,” Maroudas adds. “The method we propose may lead to breaking the bottleneck.” (more…)
Ion Tiger Fuel Cell Unmanned Air Vehicle Completes 23-Hour Flight
This photo shows the Ion Tiger in flight. The 550-watt fuel cell is show in the box in the lower left corner. (Naval Research Laboratory)
The Naval Research Laboratory’s (NRL’s) Ion Tiger, a hydrogen-powered fuel cell unmanned air vehicle (UAV), has flown 23 hours and 17 minutes, setting an unofficial flight endurance record for a fuel-cell powered flight. The test flight took place on October 9th through 10th at Aberdeen Proving Ground. The Ion Tiger fuel cell development system team is led by NRL and includes Protonex Technology Corporation, the University of Hawaii, and HyperComp Engineering. The program is sponsored by the Office of Naval Research (ONR).
The electric fuel cell propulsion system onboard the Ion Tiger has the low noise and signature of a battery-powered UAV, while taking advantage of hydrogen, a high-energy fuel. Fuel cells create an electrical current when they convert hydrogen and oxygen into water, with only water and heat as byproducts. The 550-Watt (0.75 horsepower) fuel cell onboard the Ion Tiger has about 4 times the efficiency of a comparable internal combustion engine and the system provides 7 times the energy in the equivalent weight of batteries. The Ion Tiger weighs approximately 37 pounds and carries a 4 to 5 pound payload. (more…)
Renewable Hydrogen Production Becomes Reality at Winery
Bruce E. Logan, the Kappe professor of environmental engineering, researches the use of hydrogen as an everyday, environmentally friendly fuel source. Here Bruce Logan (right) and Shaoan Cheng examining microbial electrolysis cells in their laboratory at Penn State. (Greg Grieco)
The first demonstration of a renewable method for hydrogen production from wastewater using a microbial electrolysis system is underway at the Napa Wine Company in Oakville. The refrigerator-sized hydrogen generator will take winery wastewater, and using bacteria and a small amount of electrical energy, convert the organic material into hydrogen, according to a Penn State environmental engineer.
“This is a demonstration to prove we can continuously generate renewable hydrogen and to study the engineering factors affecting the system performance,” said Bruce E. Logan, Kappe professor of environmental engineering. “The hydrogen produced will be vented except for a small amount that will be used in a hydrogen fuel cell.” Eventually, Napa Wine Company would like to use the hydrogen to run vehicles and power systems. (more…)
New Material May Expand Uses for Solid Oxide Fuel Cells
Georgia Tech researchers Meilin Liu, Mingfei Liu, Lei Yang and Kevin Blinn examine test results for their new fuel cell material. (Georgia Tech Photo: Gary Meek)
A new ceramic material described in this week’s issue of the journal Science could help expand the applications for solid oxide fuel cells – devices that generate electricity directly from a wide range of liquid or gaseous fuels without the need to separate hydrogen.
Though the long-term durability of the new mixed ion conductor material must still be proven, its development could address two of the most vexing problems facing the solid oxide fuel cells: tolerance of sulfur in fuels and resistance to carbon build-up known as coking. The new material could also allow solid oxide fuel cells, which convert fuel to electricity more efficiently than other fuel cells, to operate at lower temperatures, potentially reducing material and fabrication costs.
“The development of this material suggests that we could have a much less expensive solid oxide fuel cell, and that it could be more compact, which would increase the range of potential applications,” said Meilin Liu, a Regent’s professor in the School of Materials Science and Engineering at the Georgia Institute of Technology. “This new material would potentially allow the fuel cells to run with dirty hydrocarbon fuels without the need to clean them and supply water.” (more…)
BlackLight Power Announces “Independent Validation” of Breakthrough New Energy Source
BlackLight Power, Inc. claims to have created a potentially commercially competitive, nonpolluting new primary source of energy that forms a prior undiscovered form of hydrogen call "hydrino." The net energy released as hydrogen forms hydrino may be two hundred times that of combustion of the hydrogen fuel with power densities comparable to those of fossil fuel combustion and nuclear power plants, according to the company.
On August 12, BlackLight Power, Inc. (BLP) issued a press statement announcing that scientists at Rowan University have for the first time independently formulated and tested fuels that on demand generated energy greater than that of combustion at power levels of kilowatts using BLP’s proprietary solid-fuel chemistry capable of continuous regeneration. Operating power systems using BLP’s chemistry, Rowan University professors have reported a net energy gain of up to 6.5 times the maximum energy potential of the materials in the system from known chemical reactions.
Further information from the news statement is as follows:
In a joint statement, Dr. K.V. Ramanujachary, Rowan University Meritorious Professor of Chemistry and Biochemistry, Dr. Amos Mugweru, Assistant Professor of Chemistry, and Dr. Peter Jansson P.E., Associate Professor of Engineering said, “In independent tests conducted over the past three months involving 10 solid fuels made by us from commercially-available chemicals, our team of engineering and chemistry professors, staff, and students at Rowan University has independently and consistently generated energy in excesses ranging from 1.2 times to 6.5 times the maximum theoretical heat available through known chemical reactions.” (more…)
One Step Closer to a Hydrogen Economy
Dr. Ragaiy Zidan has conducted internationally recognized research on materials for hydrogen storage.
Researchers at the U.S. Department of Energy’s Savannah River National Laboratory have created a reversible route to generate aluminum hydride, a high capacity hydrogen storage material. This achievement is not only expected to accelerate the development of a whole class of storage materials, but also has far reaching applications in areas spanning energy technology and synthetic chemistry.
“We believe our research has provided a feasible route to regenerate aluminum hydride, a high capacity hydrogen storage material,” says Dr. Ragaiy Zidan of SRNL, lead researcher on the project. The SRNL team, supported by the DOE Office of Energy Efficiency and Renewable Energy, has developed a novel closed cycle for producing aluminum hydride (AlH3), also known as alane, that potentially offers a cost-effective method of regenerating the hydrogen storing material in a way that allows it to repeatedly release and recharge its hydrogen. In this process, the hydride is made via an electrochemical method, and the starting material is regenerated directly with hydrogen. Although many attempts have been made in the past to make alane electrochemically, none of these previous attempts were totally successful. (more…)
High-Pressure Compound Could Be Key to Hydrogen-Powered Vehicles
70MPa high-pressure hydrogen storage cylinder so far has been one solution.
A hydrogen-rich compound discovered by Stanford researchers is packed with promise of helping overcome one of the biggest hurdles to using hydrogen for fuel–namely, how do you stuff enough hydrogen into a volume that is small enough to be portable and practical for powering a car?
The newly discovered material is a high-pressure form of ammonia borane, a solid material which itself is already imbued with ample hydrogen. By working with the parent material at high pressure in an atmosphere artificially enriched with hydrogen, the scientists were able to ratchet up the hydrogen content of the material by roughly 50 percent. “Including the hydrogen already stored in ammonia borane, this new material can store around 30 weight percent in total,” said Yu Lin, lead author of a paper describing the work that was published this week in the online edition of Proceedings of the National Academy of Sciences. (more…)
Solar-Based Water-Splitting Hydrogen Production Gets a Boost
Scanning electron microscope image of typical titania nanotubes for a photocatalytic cell to produce hydrogen gas from water. Nanotubes average roughly 90-100 nanometers in diameter. Follow this link for an image showing schematic of an experimental photocatlytic cell. (Credit: Menon, Northeastern University)
A research team from Northeastern University and the National Institute of Standards and Technology (NIST) has discovered, serendipitously, that a residue of a process used to build arrays of titania nanotubes—a residue that wasn’t even noticed before this—plays an important role in improving the performance of the nanotubes in solar cells that produce hydrogen gas from water. Their recently published results* indicate that by controlling the deposition of potassium on the surface of the nanotubes, engineers can achieve significant energy savings in a promising new alternate energy system.
Titania (or titanium dioxide) is a versatile chemical compound best known as a white pigment. It’s found in everything from paint to toothpastes and sunscreen lotions. Thirty-five years ago Akira Fujishima startled the electrochemical world by demonstrating that it also functioned as a photocatalyst, producing hydrogen gas from water, electricity and sunlight. In recent years, researchers have been exploring different ways to optimize the process and create a commercially viable technology that, essentially, transforms cheap sunlight into hydrogen, a pollution-free fuel that can be stored and shipped. (more…)
Scientists Develop a Unique Approach for Splitting Water into Hydrogen and Oxygen
Profs. David Milstein (left) and Ronny Neumann of the Weizmann Institute's Organic Chemistry Department.
The design of efficient systems for splitting water into hydrogen and oxygen, driven by sunlight is among the most important challenges facing science today, underpinning the long term potential of hydrogen as a clean, sustainable fuel. But man-made systems that exist today are very inefficient and often require additional use of sacrificial chemical agents. In this context, it is important to establish new mechanisms by which water splitting can take place.
Now, a unique approach developed by Prof. David Milstein and colleagues of the Weizmann Institute’s Organic Chemistry Department, provides important steps in overcoming this challenge. During this work, the team demonstrated a new mode of bond generation between oxygen atoms and even defined the mechanism by which it takes place. In fact, it is the generation of oxygen gas by the formation of a bond between two oxygen atoms originating from water molecules that proves to be the bottleneck in the water splitting process. Their results have recently been published in Science. (more…)
New Storage System Design Brings Hydrogen Cars Closer to Reality
By Emil Venere
Issam Mudawar, from left, a Purdue professor of mechanical engineering, discusses a hydrogen-storage system for cars with graduate student Milan Visaria and Timothée Pourpoint, an assistant professor of aeronautics and astronautics and manager of the Hydrogen Systems Laboratory. Researchers have created the system's heat exchanger, which is critical because it allows the system to be filled quickly. (Purdue News Service photo/Andrew Hancock)
Researchers have developed a critical part of a hydrogen storage system for cars that makes it possible to fill up a vehicle’s fuel tank within five minutes with enough hydrogen to drive 300 miles.
The system uses a fine powder called metal hydride to absorb hydrogen gas. The researchers have created the system’s heat exchanger, which circulates coolant through tubes and uses fins to remove heat generated as the hydrogen is absorbed by the powder.
The heat exchanger is critical because the system stops absorbing hydrogen effectively if it overheats, said Issam Mudawar, a professor of mechanical engineering who is leading the research.
“The hydride produces an enormous amount of heat,” Mudawar said. “It would take a minimum of 40 minutes to fill the tank without cooling, and that would be entirely impractical.” (more…)
Surveillance Vehicles Take Flight Using Alternative Energy
This photo shows the Ion Tiger. (Credit: US Naval Research Laboratory)
Nearly undetectable from the ground, unmanned aerial vehicles (UAVs) are widely used by the military to scan terrain for possible threats and intelligence. Now, fuel cell powered UAVs are taking flight as an Office of Naval Research (ONR)-sponsored program to help tactical decision-makers gather critical information more efficiently… and more quietly.
Piloted remotely or autonomously, UAVs have long provided extra “eyes in the sky” especially for missions that are too dangerous for manned aircraft. This latest technology is showcased by Ion Tiger, a UAV research program at the Naval Research Laboratory (NRL) that merges two separate efforts — UAV technology and fuel cell systems. (more…)
Stainless Steel Replaces Platinum in Hydrogen Producing Microbial Electrolysis Cells
Bruce Logan and Shaoan Cheng examining microbial electrolysis cells (MECs) in their laboratory at Penn State. (Greg Grieco /Penn State)
Platinum is highly desired in jewelry and as a catalyst, but in both cases it is expensive. Now, Penn State researchers have found a way to replace the platinum catalyst in their hydrogen generating microbial electrolysis cells with stainless steel brushes without losing efficiency.
“Stainless steel brush cathodes can produce hydrogen at rates and efficiencies similar to those we have achieved with platinum-catalyzed carbon cloth,” says Bruce E. Logan, Kappe professor of environmental engineering.
The brushes used were made of 304 stainless steel, had a twisted stainless steel core and were manufactured on an industrial brush manufacturing machine. At an inch in length and an inch in diameter, the brushes had 48 square inches of surface area. (more…)
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