Ergenics Readies for Hydrogen Future
By EV World
31 May 1999 -- Fuel cells promise to transform the world in which we live, especially the way we get around. Fuel cells produce no pollution and run on the most abundant energy source in the universe, hydrogen. But storing enough hydrogen to provide a fuel cell-powered electric car or bus presents a problem. The lightest of all gases is difficult to store and requires large cylindric tanks to hold enough gas to give an EV sufficient cross-country range. In Daimler-Benz's NECAR3 experimental A-Class Mercedes, the methanol fuel processor took up all of the rear seat space, leaving only room for the driver and one passenger. Obviously, we can't have cars that are rolling storage tanks.
One possible solution to the hydrogen storage problem are reversible hydrides, metal alloys which act as sponges that "soak up" hydrogen gas at normal atmospheric pressures. One company that is developing just such technology is Ergenics of Ringwood, New Jersey.
The Promise of Hydrogen
David H. DaCosta, the president of Ergenics explained to EV World how hydrogen is not only plentiful and non-polluting but extremely powerful as a fuel. "Hydrogen has great energy density," he said. " More energy by weight than any other fuel."
While much of the universe is composed of hydrogen, here on earth, we get most of our hydrogen from natural gas through a relatively inexpensive process called steam reforming, DaCosta said. However, in the future he envisions hydrogen being converted from renewable sources either by solar electrolysis or from biomass. In the case of solar electrolysis, photovoltaic cells would create electricity which would, in turn, "crack" water into its two atomic parts, hydrogen and oxygen or H2O, chemically. (See also EV World's interview with John Turner on NREL's solar hydrogen breakthrough).
As for the question of hydrogen's safety, DaCosta admitted that, like gasoline, it needs to be handle with care. It is a flammable substance. However, he pointed out that all the taxi cabs in Taiwan have safely used compressed natural gas for years. "They all had a compressed gas tank in the trunk ("boot") and they'd developed a way of using that in a safe manner, and it's an established part of their society. It has been used safely for almost twenty years.
When "burned" in an internal combustion engine, hydrogen does produce nitrogen oxides (NOX) pollutants, DaCosta said. This is one reason why car makers are more interested in using the gas in a fuel cell than as a fuel for ICEs. In a fuel cell, the hydrogen is reunited with atmospheric oxygen to create water. In the process it also generates an electrical current, enabling a car to run on electricity.
Getting Hydrogen From Other Sources
DaCosta said he has "a real problem" with the current approach being taken by car companies to use either methanol or even gasoline as a liquid source of hydrogen. The reason Detroit is looking at these fuels is because there is an existing infrastructure. "With every gas station on every corner, it's pretty easy and doesn't need a lot of extra effort to put liquid fuels into cars. So, if you can get the hydrogen for a fuel cell from that liquid fuel after it's onboard a car, you don't need to make any large infrastructure changes."
"But the difficulty I have with that," he continued, "is that we'd still be using precious, non-renewable resources like gasoline, which I think ought to be preserved for making materials like plastic for future generations. Also, removing hydrogen from liquid fuel does cause pollution. It's less than burning the liquid fuel directly, but we'd still be releasing huge quantities of greenhouse gases into the air."
Ergenics' president did agree that programs like the recently completed Plug Power and Epyx gasoline reformer fuel cell test which showed an overall system efficiency of 40% was was good interim solution as we "move towards a hydrogen fuel economy."
A Cup Full of Hydrogen
The Ringwood, New Jersey-based company specializes in research into what DaCosta calls "reversible metal hydrides" which can store hydrogen.
"We've been working in the field for over twenty years and I think we're approaching the point where our technology and the market are coming together," he said.
The alloys that Ergenics is developing have the ability to absorb, like a sponge, huge quantities of hydrogen at room temperature and normal atmospheric pressure. "We can store more hydrogen in a cup of hydride alloy powder than you could store if you had a cup of liquid hydrogen. Then just like squeezing a sponge to get the water out, hydrogen is easily released from the alloy to go to a fuel cell to produce electricity." DaCosta's company uses waste heat to release the hydrogen.
Conceivably, the fuel cell car of the future could have a "fuel tank" made of steel or aluminum which would contain hydride alloy powder for absorbing hydrogen. DaCosta said his company already makes such containers, essentially for hydrogen researchers and not for actual use in a fuel cell EV. However, DaCosta thinks it makes better economic sense to still use compressed hydrogen cylinders on the vehicle, itself.
"I think (hydride tanks onboard the car) will prove out to be prohibitive," he said, "compared to a nice, advanced, light weight, carbon-fiber wrapped tank in which you can safely store (hydrogen). Where I see hydrides coming into the transportation picture is to supply a lot of supporting functions for a hydrogen fuel transportation industry."
DaCosta sees reversible metal hydrides being used as hydrogen compressors. Ergenics has patented a process that uses waste heat and a series of hydride vessels of progressively higher compression capabilities to compress hydrogen and then store it for later use in vehicles. His compressors are hermetically sealed, use no electrical power, and operate silently.
"Ergenics can envision every gas station with a hydride compressor to refuel vehicles." He went on to explain that not only can hydrides be used to compress and store hydrogen, it also has some other practical benefits including air conditioning. "Hydride air conditioners used onboard vehicles will conserve even more energy," he stated.
Fuel Cell-Powered Computers and Cellphones
"Where hydride storage makes the most sense for fuel cells," DaCosta observed, "is for smaller units, either for small stationary power sources or portable power sources that people may carry, their computers, radios or other electronic devices."
What he foresees are micro fuel cells that get their power from either rechargeable or disposable hydride energy packs. "The user would take the pack and just drop it into the back of his device and use that hydride until its energy is expended."
DaCosta remarked that this is "green technology" that would not degrade or pollute the environment like lead-acid or NiCad batteries. The alloys consist mainly of calcium and nickel and are completely benign.
While Ergenics produces small quantities of hydrides, DaCosta said he looks to other companies who currently manufacture the hydrides in large quantities. As for the elements that make up reversible hydrides, he listed lanthanum and nickel, which in alloy form is considered the "grandfather" of room temperature hydrides. He also mentioned iron titanium, as well as a very inexpensive hydride make up of calcium and nickel.
Solving the Impurity Problem
Ergenics has, of late, focused its efforts on developing hydride systems which continue to operate on less than 100% pure hydrogen, or hydrogen that contains some impurities. "In the past, impurities like moisture or air would rapidly poison a hydride alloy, preventing it from working," he said. "We now produce hydrides which tolerate impure hydrogen. This is an important milestone when you look at the widespread use of hydrogen, although it will still be important to have relatively pure hydrogen. Impurities that do get into the gas won't ruin hydride devices."
HyStor Battery For Fuel Cell Cars
Another recent development by Ergenics is its HyStor battery. It is intended to serve as a energy storage device for regenerative braking in a fuel cell vehicle. DaCosta briefly explained how the system works.
"It consumes hydrogen to produce power, but unlike the fuel cell, it's rechargeable. When you apply power to it, it will release hydrogen which we store in a separate hydride storage unit. It's at the point where it's been fully proven in the laboratory. We can produce tremendously high power pulses with it for acceleration and we can absorb high power pulses resulting from regenerative braking where you capture that breaking action as electricity rather than throwing it away as heat. We're at the point with the battery where we're ready to talk with vehicle companies, also their traditional suppliers about commercializing it.
A 300 Wh HyStor battery would measure approximately 6 inches on a side, while a 3kWh battery would measure 6 inches wide by 6 inches high by 30 inches long.
DaCosta's company is privately held, but he left open the possibility of a future public offering to help raise funds to help them grow the business. He sees Ergenics' growth developing in lock step with the spread of fuel cell technology. He said he'd focus company development efforts on three major areas: hydrogen storage, compression and refrigeration capabilities of hydrides.
As for when we can expect to see the widespread adoption of hydrogen as a fuel, he said its already happening, pointing to United Technologies' sale of some 200 plus fuel cell generators around the world to electric utilities and industry. He also pointed to companies like Plug Power and Energy Partners who already have in early trials small-scale fuel cell generators for residential use. He listed other companies who are actively moving forward with the installation of devices that utilize hydrogen as their fuel source.
Clearly, the more companies and institutions who enter the fuel cell race, the better it will be for Ergenics and for the world.
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