Nano, Nano! - Part 2
By Bill Moore
If mankind is ever going to transition away from our over-dependence on fossil fuels - - and not to do so expeditiously invites global disaster - - we have to come up with a clean, renewable energy substitute and at present, hydrogen is the best candidate. But hydrogen, which is an energy carrier, has to be stored in concentrations sufficient enough to produce useful amounts of energy. This is especially true in the case of the modern automobile.
There are a number of strategies being investigated including the onboard generation of hydrogen from conventional liquid fuels to reactive chemistries of solid minerals like sodium borohydrite.
Nanotube technology is of great interest because it might offer a relatively inexpensive medium in which to store sufficient quantities of pure, gaseous hydrogen safely to give a motor vehicle useful working range or a laptop computer useful working time.
It's the promise of the huge automotive market, which turns out 60 million new vehicles every year - - each requiring a fuel tank of some sort - - that is driving much of current nano-scale structure research.
"It's certainly clear that hydrogen storage in the automotive context is a very, very big deal," Jeff Wyatt observed, noting that, "a company like Nanomix cannot do it alone.
"We need to develop the product jointly with both automobile companies and the fuel providers, the major energy companies, the ChevronTexacos, the BPs and Shells of the world. So, we will form partnerships and joint ventures and license the technology as needed to get it into the marketplace. Our objective is to see this cold hydrogen storage technology on every vehicle that's manufactured in 2010."
The challenges facing a small, two-year-old startup like Nanomix are significant. They must first identify the most likely nano material, be it carbon, boron or something yet to be discovered, and then come up with a scaleable mass manufacturing process, all of which require time, talent and money. Certainly, Nanomix appears to have the prerequisite talent, with the company co-founders being two of the leading research scientists in the field. The time equation is partly a function of the money available and the pace of the competition, not only from other nano-structure researchers but also from other hydrogen storage methods.
A Window of Opportunity
One thing is obvious at this point, none of the automakers have yet settled on which storage technology makes the most sense. GM is working with Quantum on a 10,000 psi compressed hydrogen tank. Clearly there is also interest in metal hydrides as witnessed by the Texaco/Ovonics partnership. From the perspective of the auto industry, practical nanotube technology may appear further out on the development time line.
Yet, according to Jeff Wyatt, cold nanotube storage technology offers clear advantages over the current competition.
"Where we see cold hydrogen energy storage technology is that it will be as energy efficient as compressed hydrogen. That is one of the principal advantages of compressed hydrogen; you don't lose much energy in that context. So, cold hydrogen will be very competitive, but it will take up less volume and it will also weigh less.
"So if what you are worried about is volumetric and gravimetric efficiency, this cold hydrogen storage will certainly work better than the 5,000 psi tank and even better than the 10,000 psi tank. The reason is what is essentially solid state hydrogen storage is more dense," he explained.
"There are two other major advantages for cold hydrogen storage compared to compressed gas. We expect it will be safer in automotive applications. It's going to be stored at low pressure, something like one hundred. . . one hundred and fifty pounds per square inch, at a pressure just high enough to feed the fuel cell."
Wyatt explained that if there were an accidental breach of the vessel or a leak, because of the low pressure and absorbent nature of the medium there would be no "catastrophic" loss of hydrogen.
The second added advantage is that the storage tanks themselves can be made conformable to any necessary shape, a distinct advantage over large compressed H2 cylinders currently in use on prototype fuel cell vehicles.
"You can make square tanks, you can rectangular tanks. That is a property the automakers value very, very highly," Wyatt stated. While he said it would take some time to develop, test and refine the technology, "from where we stand right now, it looks like it has some very substantial advantages compared to compressed hydrogen."
Turning to the other major competitor, metal hydrides, Wyatt believes cold hydrogen storage, nanotube technology performs better in all but one area, volume. "Metal hydrides have very low volume, but on the other hand, very, very high weight."
He pointed out that even with the most advanced metal hydride materials, the storage system alone comprises 10 percent of the overall weight of the vehicle.
"The people we are talking to in the industry are moving away from metal hydrides at this point, principally because of the weight problem and the amount of energy it takes to get the hydrogen out of the metal hydride." He said that the current generation of hydride storage systems must be heated to 300 degrees C to force the hydrogen out of the tank.
By contrast, Nanomix's system in which the hydrogen is stored at 80 degrees Kelvin (-315F/193C) is contained in an insulated tank and would require only the addition of warm outside air to force the hydrogen from its nanotube lattice. In their system, the H2 filling station (forecourt) would store the hydrogen at these super-cold temperatures. (Liquid hydrogen must be cooled to 253 degrees F.) He believes the hydrogen in their insulated tank will remain cold for at least one to two months.
Wyatt sees a low-pressure cold hydrogen storage tank made of aluminum wrapped in an insulating blanket. Inside of this is the nanotube or similar nano-scale absorbent that's made with "cheap raw materials like natural gas and air."
According to Wyatt, carmakers want to see a fuel storage system that costs under $1000 per vehicle and the cheaper the better. Nanomix believes that with modest volumes of several tens of thousands of fuel cell vehicles, their system would cost under $500 per vehicle.
Such a tank would hold about 5-6 kilograms (11-13 lbs.) of hydrogen, which is enough, depending on the efficiency of the vehicle, to give the car or truck a range of between 300 and 400 miles.
This discussion of nanotube storage tanks isn't purely theoretically, either. Nanomix has had a prototype tank in operation since January, 2002.
"We are in the design phase of our Mark II prototype," Wyatt told EV World. "We see the Mark IV prototype being an automotive prototype in early 2004. That's our development target." He added that Nanomix believes it has a viable automotive hydrogen storage system today from a technical perspective. Now the challenge is to form the necessary partnerships to be able to go into commercial production of the storage medium and tanks, as well as continue research into even more promising materials than carbon nanotubes.
"Certainly the nano materials that are the best candidate today are carbon-based. That will work today. We've got some candidates that we think will work in two or three years that will be better than carbon," Wyatt said.
"The systems that we are designing, the prototypes that we envision for an automotive prototype will work with any of these materials."
The Mouse in the Lion's Den
As might be expected, at least two automakers have paid reciprocal visits to Nanomix, but Wyatt said that the company has to be very discreet at this point, like the "mouse in the lion's den," as he put it.
Since cost is a huge consideration in the highly competitive automotive industry, one bright spot is the that fact carbon nanotube costs have fallen dramatically over the last several years. Wyatt noted that up until just three years ago, if you wanted just one gram of this material, you'd have to set up your own laboratory to make it yourself. The cost was about $1 million/gram.
"Today, three years later, companies like Mitsubishi, Matsui, DuPont, Dow are all beginning to build facilities to manufacture carbon nanotubes. So if you look at the costs, what you can buy them for, the cost is just screaming down exponentially."
This of course, poses a potential problem for a small company like Nanomix who, it would seem, has to compete against these industrial powerhouses. But Wyatt is upbeat about this challenge.
"What we're trying to do is to identify materials that not only offer the best performance in this application but that are also low cost."
Nanomix has some half-dozen patents filed on its technology, so Wyatt was a bit elusive about these new materials, saying only they offer better performance and cost than carbon nanotubes.
As for its business model, Wyatt explained that the company is trying to pattern its development similar to the biotech firms with whom it shares Silicon Valley and the Bay Area.
A Bio Tech Business Model
"We think we know how to play that game through developing very, very strong intellectual property patents and putting together partnerships and joint ventures and licensing so that we can navigate our way through this alligator-infested swamp."
The day of our interview, Nanomix was closing on its second round of venture capital funding, giving the company what Wyatt calls a "two year of runway."
"At this point in time, we certainly are always interested in talking with potential investors, but our focus over the next twelve to eighteen months is really going to be lining up these partnerships that we need to make happen so that the technology can get to the marketplace."
Of course, given the recent pandemic of corporate book cooking and thievery, potential investors have a right to be skeptical about any business that comes along promising to revolutionize some segment of industry or the market, but Wyatt took a firm stand defending Nanomix's legitimacy.
"The investors that are joining our second round are top tier venture capital firms, people that have been in the business for many, many years. They're highly skeptical, highly educated people, so the fact that they're investing in Nanomix is a major vote of confidence both in the company and in the technologies we're developing.
"And to potential investors out there, I say just watch us and see what we can do [in] the next year or two."
blog comments powered by Disqus