Transformational Technology: Polyfuel's New Fuel Cell Membrane Could Unplug Solar Chargers
by TreeHugger on 05. 7.05
This is a Toshiba prototype of a direct methanol fuel cell (DMFC), which is described as about "as long and wide as a woman's thumb". Based on the progress being made in underlying technologies for DMFC's in general, TreeHuggers will be thumbing them soon, and at the same time waving goodbye forever to lithium batteries and portable chargers. Below is some market context based on one example of technology progress leading to DMFC commercialization.
MOUNTAIN VIEW, CA – May 4, 2005 – The president of U.S.-based PolyFuel, Inc., a Mr. Balcom, warned last week that "U.S. companies are in danger of completely missing the boat in micro-power fuel cells through a sheer lack of market awareness. Micro-power fuel cells are...expected by technologists ...to supplant or replace batteries in increasingly power-hungry portable devices such as laptops and mobile phones".
Several firms have working prototypes of fuel-cell-powered phones and computers, with commercial sales expected to begin in Japan in about 2 years (same market entry path as the Prius). Most of the prototype DMFC's extract hydrogen directly from methanol, delivered from a removeable cartridge. The micro-fuel cell membranes are postage stamp to playing-card scale, and operate at comfortably low temperatures. Existing prototypes already run up to 8 hours on asmall volume of fuel.
Mr. Balcom, whose company PolyFuel makes advanced polymer membranes for DMFC's, stated in the company's press release that he frequently sees evidence of the Asian-US disconnect on this transformational technology. “The interest in our membrane is so high in Asia – and increasingly in Europe – that it dominates our activities. We are already working with a number of major Japanese and Korean manufacturers, and we expect prototypes to be available within the next 12 to 24 months. I fear, however, that by the time the trendy applications take root here in the U.S., the design and manufacture of micro-power fuel cells will be firmly entrenched offshore. That ship will have sailed. In North America, only those of us with critical enabling technology will participate.” This scenario, said Balcom, "is not unlike that of Lithium ion batteries, whose technologies were predominantly developed in the U.S. but commercialized first in Japan". Yes, TreeHuggers: the underlying technology for micro-fuel cells comes from US patents.
Third generation hand held phones using DMFC power will be capable of high-speed connections that allow users to access the same information as a PC does using broad-band Internet connection, consuming power at much higher rates and for longer periods. DMFC arrival at commercially competitive prices is the rate limiting factor for high-bandwidth technology that will transform serivces offered on many hand-helds, triggering a ripple effect to other electronic devices. And that arrival date is coming fast.
As with all transformational technologies there can be some sad debris. The obvious one is elimination of recharger bricks, their input and output wires, and the internal batteries and battery packs they feed. Imagine the electronic waste coming from this. The less obvious secondary impact could be on the innovative solar backpack-type chargers that have been getting excellent coverage here in TreeHugger.
Don't let methanol scare you, TreeHuggers. Its very bad to drink, to be certain, so it will be sold in containers that discharge liquid MeOH when attached to the fuel cell block. Luckily, methanol is to aquatic bacteria as chocolate is to humans. Spill it down the drain and it biodegrades very quickly. It has to be pure (no denaturants added) for the DMFC so toxicity will be less. And it may be sold as a dilute solution, accomplishing a reduction in fire hazard as well.
Don't assume that lithium batteries are more benign and therefore 'better'. The liquid electrolyte in lithium batteries can pose a serious contact hazard in the presence of moisture, including that from human perspiration. The materials of lithium batteries are energy intensive to make as well. Truth be told, only a small fraction of electronic device batteries are collected for recycle programs because they have low intrinsic material value and are so easily tossed: 'out of sight and out of mind' as it were. Methanol cartridges may end up the same way, but at substantially less risk of hazardous exposure and loss of embodied energy and material.
The rapid and unstopable trend to transformative DMFC's for handheld power production is further evidence in support of my "Island USA Scenario", where green product designs and market plans increasingly originate elswhere. US TreeHuggers have to get more involved in industrial policy making unless they are comfortable in their role as passive consumers.
Look for much more about this subject in coming posts.
by John Laumer
Any comments on the environmental impact of methanol production? Seems to be getting popular as a fuel.
B
Methanol synthesis is accomplished by several routes; some directly and with intent of making it as a pure product; or as a "co-product" of other reactions. Windshield washer fluid, which is simply a dilute methanol and othr alcohol solution dyed blue (denatured)can be made of the byproduct of the plastics industry for example. Last I bought some it was about a buck thirty a gallon. In this case its use it as a coproduct or burn it as a waste; so use as a fuel is definitely an environmental positive.
Methanol is simply oxygenated methane, as obtained from natural gas wells or from biogas (from anaerobically fermented sewerage sludge, manure, agricultural residue, etc). The oxtgen comes from water molecules. The reaction if gas and water is done in a gas heated "steam reformer" in the presence of catalysts such as zinc and copper. Combustion of natural gas to heat the reformer unit and drive the reaction releases C02 and water vapor of course. There are fancy heat recovery equipment loops used to keep efficiency up; chillers to capture fugitive methanol vapors; sulfer removal scrubbers; and possibly reverse osmosis membranes to dry out the product. These all use energy.
It seems to be a moderately energy intensive process overall, with no notably toxic outputs save the spent catalyst, and that would be in trivial quantity and recyclable for metal value.
The factories themselves have a small footprint and seem often to be located near to large natural gas wells. I noticed a big one in Trinidad for example.
There is no reason why locally produced biogas streams could not be used to produce methanol to meet local needs. It would take someone with more process background than I have to identify best methods. A subject for another day and another post perhaps.
Why methanol versus ethanol?
It is certainly possible to design an ethanol fed fuel cell, theoretically. However, there are two issues right out of the gate that may have led designers to methanol first. Because ethanol is regulated intensely and taxed significantly if it is not denatured, the political issue of getting to use it as a "neat" fuel would be daunting. Note that this is not an issue with EtOH added to gasoline, because there it is obviously a non-consumable. The second issue is more significant. Its the hydrogen (H) to carbon (C) ratio per mole of fuel. Methanol has 1-C,4-H,1-O, so ratio of H/C = 4 for it. Ethanol, however, has 2-C, 6-H, 1-0, so H/C ratio = 3. Per mole equivalent of electricity produced, ethanol liberates a third more carbon dioxide and requires a third more external 02 supplied. By definition then, the energy density of methanol, at least in a fuel cell, is 33% greater than for ethanol.
This below verbatim from a battery engineering professor at MIT. Since I didn't ask him if I could quote him here, I keep it anonymous.
"It's hard to say. Methanol is flammable and so it presents a security risk -- flame throwers on airplanes? The slams against Li-ion on environmental grounds is intellectually dishonest. These people should be ashamed of themselves. Ask DMFC people what happens to the carbon in methanol. Answer, the anode reaction converts methanol into CO2 and protons and electrons. How much greenhouse gas does the DMFC emit? The technology is a joke."
His words, not mine... Time will tell which technology wins mass market in the end.
Look up the health effects of lithium flouro-hosphate before you decide that potential health effects of that electrolyte component are trivial.
There's certainly room for both the Li batteries and for DMFC's in our world. Its not a contest based on single attributes. For example: Straight off comparison of "fire and explosion risk", as clearly stated on most high energy density batteries makes it clear to any open minded person that there is risk with both approacahes.
Incidentally., the MeOH you have in your car windsheild washer fluid tank is no more risky than what will be in a DMFC. The arguement I'm really making is that a circumspect risk assessment needs to be done by a team of people: not just a single expert. The product comparison needs also to look at the embodied energy and meterials per Kg/product per year of design life. On that basis alone my money is on DMFC's winning hands down.
Please allow one more belated thought. Of course the DMFC emits C02. How else could it liberate hyddrogen for the electrochemical reaction? The only difference between the DMFC and a rechargeable battery is that the battery (generally speaking) emits its C02 from a coal burning power plant operating off a 40 year old design and losing up to 6% of the power over transmission lines on the way to our homes, wher we use plug in transformers to recharge out batteries. These transformer blocks have been shown to consume up to 10% of a typical home's electricity. Again, the point is that a full life cycle comparison of embodied and operating energy is needed before a judgement is reached on superiority.