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Archive for the ‘Hydrogen’ Category

Kouji Kariatsumari, Nikkei Electronics, June 13, 2008

Genepax Co Ltd explained the technologies used in its new fuel cell system “Water Energy System (WES),” which uses water as a fuel and does not emit CO2.

The system can generate power just by supplying water and air to the fuel and air electrodes, respectively, the company said at the press conference, which took place June 12, 2008, at the Osaka Assembly Hall.

The basic power generation mechanism of the new system is similar to that of a normal fuel cell, which uses hydrogen as a fuel. According to Genepax, the main feature of the new system is that it uses the company’s membrane electrode assembly (MEA), which contains a material capable of breaking down water into hydrogen and oxygen through a chemical reaction.

Though the company did not reveal the details, it “succeeded in adopting a well-known process to produce hydrogen from water to the MEA,” said Hirasawa Kiyoshi, the company’s president. This process is allegedly similar to the mechanism that produces hydrogen by a reaction of metal hydride and water. But compared with the existing method, the new process is expected to produce hydrogen from water for longer time, the company said.

With the new process, the cell needs only water and air, eliminating the need for a hydrogen reformer and high-pressure hydrogen tank. Moreover, the MEA requires no special catalysts, and the required amount of rare metals such as platinum is almost the same as that of existing systems, Genepax said.

Unlike the direct methanol fuel cell (DMFC), which uses methanol as a fuel, the new system does not emit CO2. In addition, it is expected to have a longer life because catalyst degradation (poisoning) caused by CO does not occur on the fuel electrode side. As it has only been slightly more than a year since the company completed the prototype, it plans to collect more data on the product life.

At the conference, Genepax unveiled a fuel cell stack with a rated output of 120W and a fuel cell system with a rated output of 300W. In the demonstration, the 120W fuel cell stack was first supplied with water by using a dry-cell battery operated pump. After power was generated, it was operated as a passive system with the pump turned off.

This time, the voltage of the fuel cell stack was 25-30V. Because the stack is composed of 40 cells connected in series, it is expected that the output per cell is 3W or higher, the voltage is about 0.5-0.7V, and the current is about 6-7A. The power density is likely to be not less than 30mW/cm2 because the reaction area of the cell is 10 x 10 cm.

Meanwhile, the 300W fuel cell system is an active system, which supplies water and air with a pump. In the demonstration, Genepax powered the TV and the lighting equipment with a lead-acid battery charged by using the system. In addition, the 300W system was mounted in the luggage room of a compact electric vehicle “Reva” manufactured by Takeoka Mini Car Products Co Ltd, and the vehicle was actually driven by the system.

Genepax initially planned to develop a 500W system, but failed to procure the materials for MEA in time and ended up in making a 300W system.

For the future, the company intends to provide 1kw-class generation systems for use in electric vehicles and houses. Instead of driving electric vehicles with this system alone, the company expects to use it as a generator to charge the secondary battery used in electric vehicles.

Although the production cost is currently about ¥2,000,000 (US$18,522), it can be reduced to ¥500,000 or lower if Genepax succeeds in mass production. The company believes that its fuel cell system can compete with residential solar cell systems if the cost can be reduced to this level.

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CHUCK SQUATRIGLIA, Autopia at Wired, June 12, 2008

Volkswagen’s hydrogen fuel cell Tiguan made its North American debut today, and it’s a pretty slick bit of kit even if it won’t appear in showrooms anytime soon, if at all.

Although the company was also showing off its upcoming diesel Jetta TDI and talking a lot about the TDI Cup diesel racing series it sponsors, the Tiguan HyMotion was clearly the star of the show. It’s an advancement over the HyMotion Touran it replaces, but company officials made it clear they aren’t betting on hydrogen alone to save us.

“There isn’t one technology, one fuel, that will provide the answer,” John Tillman, who leads VW’s advanced powertrain division in the U.S, told Wired.com. “We have multiple technologies. This is just one of them.”

The company is pushing clean diesel in a big way and expects it to comprise 30% of its sales within a decade. But, like a growing number of automakers, it believes “the electric motor is the ideal prime mover for sustainable economy,” and Tillman says VW is working on hybrid and battery electric drivetrains.

Volkswagen’s been playing with fuel cells for 10 years now, and it launched a dedicated fuel cell and EV research center in 2001. The Tiguan HyMotion is its fourth generation FCV and the its most advanced.

The proton exchange membrane fuel cell generates 80 kW, but it’s coupled with an electric motor and lithium-ion battery that bump output to 100 kW (about 134 horsepower). That’s enough to propel the Tiguan, which weighs about 4,122 pounds, from zero to 60 in 14 seconds and a top speed of 93 mph. Not great, but better than the Touran’s 86 mph. The battery has a charge capacity of 6.8 Ah and is charged by the fuel cell and regenerative braking. The HyMotion also uses stop-start technology to reduce fuel consumption.

Besides their astronomical price, one of the shortcomings of fuel cell vehicles is their range, and the Tiguan offers a relatively paltry 160 miles. It carries 3.5 kilograms of gaseous hydrogen in a tank made of carbon fiber, kevlar and aluminum at a pressure of 10,000 pounds – twice that of the Touran. “We could go higher, but who’s going to provide the fueling infrastructure at that pressure?” said Westley Khin, one of the engineers who worked on the car.

Ah yes, the fueling infrastructure. The Achilles heal of fuel cell vehicles, along with the astronomical cost of the cars themselves. Khin concedes both are the big stumbling blocks to the commercialization, but says “the vehicles are here” and they work well. That may be, but VW’s only built two HyMotion Tiguans and doesn’t have any plans to start putting them in driveways like Honda’s doing with the FCX Clarity.

“The FCX Clarity is a good vehicle. But we want to introduce a vehicle when the customer has the capacity to fuel it. We don’t see that happening anytime soon,” Tillman says, adding that VW is “working on developing” a home-hydrogen station along the lines of what Honda’s got.

By the way, we asked Tillman if there’s any chance we’ll see that sweet 71 mpg diesel-electric Golf hybrid VW unvieled earlier this year at the Geneva Motor Show. “We’re looking at it. I don’t have a timeline, but we are looking at it,” is all he’d say.

VW realizes there’s a market for the car but says the problem is making it affordable. Hybrid drivetrains are expensive – they add about $5K to the sticker price. So are diesel engines, which cost about two grand more than similarly-sized gasoline engines. Put them together in the same car and things quickly get expensive. “We have to get it to a price point that people can actually afford,” Tillman said.

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NINA LARSON, Agence France Presse, May 13, 2008

How to keep the lights on when all is still and the local windmill won’t budge? A small Norwegian island testing a way to store wind-generated energy for calm days may have found the answer.

The tiny, windswept island of Utsira, situated off Norway’s southwestern coast, is home to what is said to be the world’s first full-scale system for cleanly transforming surplus wind power into hydrogen.

Perched atop a 40-metre-high wind turbine on a perfectly windstill day, technician Inge Linghammer explains that at times like this or on days when the gales whipping the unsheltered island get too strong the windmill shuts down and stops pumping out power.

“You need to have back-up power when this happens,” he says, nodding towards the motionless blades.

On a good day, the island’s two wind turbines, planted on a small hill overlooking several red-painted wooden houses, produce more energy than the 210 people living here can use.

When they are down however, most of Utsira, which measures only six square kilometres, is furnished with electricity from the mainland.

But 10 households receive clean, wind-generated electricity regardless of the weather conditions, thanks to a pilot project launched here in July, 2004 making it possible to store wind power by transforming it into hydrogen.

Surplus wind-generated energy is passed through water and, using electrolysis, the hydrogen atoms are separated from the oxygen atoms that make up water molecules.

The hydrogen is then compressed and stored in a container that can hold enough hydrogen gas to cover the energy needs of the 10 households for two windless days.

“Utsira has more than enough wind power to be self-sustained … but the problem arises on a day like today when there is not enough wind,” explains Halgeir Oeya, who heads up the hydrogen technology unit at Norwegian energy giant StatoilHydro, which is running the project.

“This system allows us to deliver power with expected quality and reliability,” he says, standing next to the large metal electrolyser box baking in the spring sun.

Combining renewable energy and hydrogen, he says, makes most sense in secluded areas like the numerous islands lining the European coast or in remote Australian communities, which until now have been heavily dependent on carbon dioxide-spewing diesel fuel provided by a constant flow of truck convoys.

Islands like Utsira have long been considered ideal laboratories for renewable energy due to their total dependence on outside energy supplies and their access to powerful wind energy.

Oeya boasts that the people participating in the Utsira test project have no restrictions on how they use power, switching on the lights, dishwashers, television sets and stereos without a thought to how the wind is blowing.

And amid growing alarm over greenhouse gas-promoted global warming, they can do so with a clean conscience, he says, pointing out that “the only emission is oxygen.”

Producing and storing energy this way however is still, nearly four years after testing began, far more expensive than the hydraulic power produced on Norway’s mainland.

StatoilHydro has no intention of building up the system to compete with large-scale energy production, but even making it competitive in the small, remote communities far off the grid that make up its target market remains years off.

“This is not a commercial project as it stands,” Oeya acknowledges.

“We must have a bigger scale in order to compete … and this will take a number of years,” he says.

Utsira mayor Jarle Nilsen is nonetheless ecstatic about the system and its effects on his small island community.

“This is a fantastic project that has been good for Utsira,” he says, pointing out that initial concerns about noise levels and birds getting caught in the turbines had been laid to rest.

“We haven’t found a single dead bird,” he says.

Most importantly, the system was helping nudge his Utsira towards its goal of zero emissions within the next decade and had become a major tourist attraction.

“The tourists go over to the lighthouse first, but then they go to look at our windmills. They want to see the world’s first full scale wind and hydrogen project in action,” he says proudly.

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ARJUN MAKHIJANI, Institute for Energy & Environmental Research, August 2007

Excerpts from Carbon-Free and Nuclear-Free: A Roadmap for U.S. Energy Policy. About this book here. Book PDF available as free download here. Executive Summary here.

The 12 most critical policies that need to be enacted as urgently as possible for achieving a zero-CO2 economy without nuclear power are as follows.

1. Enact a physical limit of CO2 emissions for all large users of fossil fuels (a “hard cap”) that steadily declines to zero prior to 2060, with the time schedule being assessed periodically for tightening according to climate, technological, and economic developments. The cap should be set at the level of some year prior to 2007, so that early implementers of CO2 reductions benefit from the setting of the cap. Emission allowances would be sold by the U.S. government for use in the United States only. There would be no free allowances, no offsets and no international sale or purchase of CO2 allowances. The estimated revenues – approximately $30 to $50 billion per year – would be used for demonstration plants, research and development, and worker and community transition.

2. Eliminate all subsidies and tax breaks for fossil fuels and nuclear power (including guarantees for nuclear waste disposal from new power plants, loan guarantees, and subsidized insurance).

3. Eliminate subsidies for biofuels from food crops.

4. Build demonstration plants for key supply technologies, including central station solar thermal with heat storage, large- and intermediate-scale solar photovoltaics, and CO2 capture in microalgae for liquid fuel production (and production of a high solar energy capture aquatic plants, for instance in wetlands constructed at municipal wastewater systems).

5. Leverage federal, state and local purchasing power to create markets for critical advanced technologies, including plug-in hybrids.

6. Ban new coal-fired power plants that do not have carbon storage.

7. Enact at the federal level high efficiency standards for appliances.

8. Enact stringent building efficiency standards at the state and local levels, with federal incentives to adopt them.

9. Enact stringent efficiency standards for vehicles and make plug-in hybrids the standard U.S. government vehicle by 2015.

10. Put in place federal contracting procedures to reward early adopters of CO2 reductions.

11. Adopt vigorous research, development, and pilot plant construction programs for technologies that could accelerate the elimination of CO2, such as direct electrolytic hydrogen production, solar hydrogen production (photolytic, photoelectrochemical, and other approaches), hot rock geothermal power, and integrated gasification combined cycle plants using biomass with a capacity to sequester the CO2.

12. Establish a standing committee on Energy and Climate under the U.S. Environmental Protection Agency’s Science Advisory Board.

Dr. Arjun Makhijani, president of the Institute for Energy and Environmental Research in Takoma Park, Maryland, is the book’s author. He holds a Ph.D. from the University of California at Berkeley, where he specialized in nuclear fusion and is a Fellow of the American Physical Society. Among his book’s recommendations:

“Continuing on a ‘business as usual’ path is unacceptable, as other experts have made clear,” Dr. Makhijani explained. “The approaches outlined in my book are all technologically feasible and economically viable today or could be made so within a decade by sound government and private investment. Nuclear power, on the other hand, entails risks of proliferation, terrorism and serious accidents. The United States can lead the world to a fully renewable, efficient energy economy, which can be achieved in 30 to 50 years.”

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DAVID EHRLICH, cleantech.com, February 18, 2008

Researchers at Pennsylvania State University have come up with a way to get hydrogen from water that tries to copy the system that plants use.

“It’s a conceptual advance, I think. Kind of a proof of principle that you can make something that uses molecules to sort of do what photosynthesis does,” Professor Thomas Mallouk told Cleantech.com.

Mallouk is the DuPont professor of materials chemistry and physics at Penn State.

The researchers worked in collaboration with Arizona State University and with backing from the U.S. Department of Energy.

The group developed a catalyst system that, combined with a dye, mimics the electron transfer and water oxidation processes that occur in plants during photosynthesis.

But don’t look for a commercial application to come out anytime soon. The technology right now is very inefficient, although Mallouk said plants aren’t doing much better.

“Photosynthesis is basically a failed system. Since it’s had a billion-plus years to evolve and has only got to 1 to 3 percent efficient,” he said.

“So we need to do better than that in whatever man-made systems we make, whether they’re molecular systems like ours or semiconductor systems like conventional solar cells.”

The researchers have so far achieved an efficiency of only about 0.3 percent. They reported the results of their experiments at the annual meeting of the American Association for the Advancement of Science over the weekend in Boston.

Current catalytic systems can make hydrogen using a so-called sacrificial reducing agent that provides the electrons needed, with the agent consumed in the process.

“What we wanted to do was do that without cheating, using water as the electron donor and make hydrogen on the reducing side and oxygen on the oxidizing side.”

The process uses a cluster of molecules about 2 nanometers in diameter with a center catalyst of iridium oxide molecules surrounded by orange-red dye molecules.

The university said the researchers picked orange-red dye because it absorbs sunlight in the blue range, which has the most energy.

When the dye is hit with visible light, the energy excites electrons in the dye, which, with the help of the catalyst, can split the water molecule.

Attempts at a similar process by other researchers have run into the problem of the hydrogen and oxygen recombining.

“If you’re driving a reaction uphill, it wants to go back downhill,” said Mallouk. “Any catalyst that is a good catalyst for doing that uphill reaction, is also a good catalyst for sending it the other way.”

“So you have a real problem. You have to somehow separate the products physically or you have to do very tricky catalyst design that will only catalyze a reaction in one direction and not the other.”

The researchers impregnated a titanium dioxide electrode with the catalyst complex for the anode and used a platinum cathode, immersing the electrodes in a salt solution, but separating them from each other to avoid the problem of the hydrogen and oxygen recombining.

While the system is a step forward in making a process that can split water without using a reducing agent, it’s still well behind current, commercially available technology.

“I don’t know if this kind of water photolysis would ever catch up with power generating solar cells hooked to electrolyzer systems,” said Mallouk.

“Those systems are pretty good and getting better, but the costs are still pretty high.”

Companies like New Jersey-based Renewable Energy International are working on a solar cell-to-electrolyzer system for residential use.

Scaling up the the Penn State system, with its iridium oxide catalyst, isn’t likely to be a cheaper proposition.

“Iridium occupies a unique position of being the most expensive element in the periodic table,” said Mallouk. “Can’t get any worse than that.”

But he did point out that nature can achieve its oxygen evolution reaction 50 times faster than they can, using manganese, which is a cheap element.

“So it’s not hopeless to make this kind of thing out of cheap materials, but it would be a long, tough road to make a fully molecular water splitting system that was really efficient and really economical.”

He said the molecular systems are interesting, from a fundamental science point of view, but that the smart money is probably on semiconductor-based nanosystems for making really efficient solar cells.

“You could picture a microscopic system that develops the voltage you need to split water and then the components of the electrolyzer right on that particle.”

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Cheap Hydrogen

KEVIN BULLIS, technologyreview.com, January 31, 2008

A new process uses sunlight and a nanostructured catalyst to inexpensively and efficiently generate hydrogen for fuel.

Nanoptek, a startup based in Maynard, MA, has developed a new way to make hydrogen from water using solar energy. The company says that its process is cheap enough to compete with the cheapest approaches used now, which strip hydrogen from natural gas, and it has the further advantage of releasing no carbon dioxide.

Nanoptek, which has been developing the new technology in part with grants from NASA and the Department of Energy (DOE), recently completed its first venture-capital round, raising $4.7 million that it will use to install its first pilot plant. The technology uses titania, a cheap and abundant material, to capture energy from sunlight. The absorbed energy releases electrons, which split water to make hydrogen. Other researchers have used titania to split water in the past, but Nanoptek researchers found a way to modify titania to absorb more sunlight, which makes the process much cheaper and more efficient, says John Guerra, the company’s founder and CEO.

Researchers have known since the 1970s that titania can catalyze reactions that split water. But while titania is a good material because it’s cheap and doesn’t degrade in water, it only absorbs ultraviolet light, which represents a small fraction of the energy in sunlight. Other researchers have tried to increase the amount of sunlight absorbed by pairing titania with dyes or dopants, but dyes aren’t nearly as durable as titania, and dopants haven’t produced efficient systems, says John Turner, who develops hydrogen generation technologies at the National Renewable Energy Laboratory (NREL), in Golden, CO.

Nanoptek’s approach uses insights from the semiconductor industry to make titania absorb more sunlight. Guerra says that chip makers have long known that straining a material so that its atoms are slightly pressed together or pulled apart alters the material’s electronic properties. He found that depositing a coating of titania on dome-like nanostructures caused the atoms to be pulled apart. “When you pull the atoms apart, less energy is required to knock the electrons out of orbit,” he says. “That means you can use light with lower energy–which means visible light” rather than just ultraviolet light.

The strain on the atoms also affects the way that electrons move through the material. Too much strain, and the electrons tend to be reabsorbed by the material before they split water. Guerra says that the company has had to find a balance between absorbing more sunlight and allowing the electrons to move freely out of the material. Nanoptek has also developed cheaper ways to manufacture the nanostructured materials. Initially, the company used DVD manufacturing processes, but it has since moved on to a still-cheaper proprietary process.

NREL’s John Turner says that Nanoptek’s process is “very, very promising.” And Harriet Kung, the acting director of the DOE’s office of basic energy sciences, which has funded Nanoptek’s work, says that the strained-titania approach is “one of the major exciting advances” since titania was first discovered to be a photocatalyst in the 1970s.

If it works as expected, the technology could help address one of the fundamental problems with using hydrogen as fuel. Hydrogen is attractive because it is light, and burning it only produces water. But today most hydrogen is made from natural gas, a process that releases considerable amounts of carbon dioxide. The other main option is electrolysis. But even if it’s powered by clean energy, such as electricity from photovoltaics, electrolysis is inefficient and expensive. Guerra says using strained titania, and Nanoptek’s inexpensive manufacturing process, makes the process cheap and efficient enough to compete with processes that create hydrogen from natural gas. What’s more, Guerra says, the Nanoptek technology can be located closer to customers than large-scale natural-gas processes, which could significantly reduce transportation costs, thereby helping make the technology attractive. And if in the future carbon emissions are taxed or regulated, Nanoptek’s carbon-free approach is another advantage.

Turner says that in addition to making hydrogen for fuel-cell vehicles, Nanoptek’s process–if it is indeed efficient and inexpensive, as the company claims–could also be important for large-scale solar electricity. If solar is ever to be a dominant source of power, finding ways of storing the energy for night use will be essential. And hydrogen, he says, could be a good way to store it.

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