Hydrogen-Powered Lawnmowers?

[C1ay]

In a breakthrough that could make fuel cells practical for such small machines as lawnmowers and chainsaws, researchers have developed a new mechanism to efficiently control hydrogen fuel cell power.

 

lefthttp://hypography.com/gallery/files/9/9/8/hlawn_thumb.jpg[/img]Many standard fuel cell designs use electronics to control power output, but such designs require complex systems to manage humidity and fuel recovery and recycling systems to achieve acceptable efficiency.

 

The new process controls the hydrogen feed to match the required power output, just as one controls the feed of gasoline into an internal combustion engine. The system functions as a closed system that uses the waste water to regulate the size of the reaction chamber, the site where the gasses combine to form water, heat and electricity.

 

National Science Foundation (NSF) awardee Jay Benziger of Princeton University developed the new technique with his student Claire Woo, a recipient of an NSF Research Experiences for Undergraduates award and now a doctoral candidate at the University of California, Berkeley. Woo and Benziger published their findings in the February 2007 Chemical Engineering Science, now available online.

 

The researchers believe the first applications for their technology will be in smaller engines. Fuel cells are currently inefficient on such scales due to the need for fuel recycling and excess hydrogen in standard designs. The researchers' new design is closed, so 100 percent of the fuel is used and there is no need for a costly fuel recycling system.

 

"The system is ideal for small internal combustion engines that lack emissions controls and are highly polluting," said Benziger. "There is also no need for an extensive hydrogen distribution system for these small motors; the hydrogen could be supplied in returnable tanks such as the propane tanks used for gas grills."

 

Benziger's next goal is to connect several of the new fuel cells together to increase power, a system that could potentially compete with cells now being tested in the automotive industry.

 

Source: NSF

[Buffy]

I don't have time to find it now, but I read somewhere recently that an unbelievable amount of our air pollution comes from the two-stroke engines in lawnmowers and leaf blowers, and the lawn-equipment manufacturers were lobbying heavily against laws seeking to limit their use, because a transition to 4-stroke would be very expensive....I think they're missing a marketing opportunity, but fuel cell mowers would be so cool that it might make them sell like hot cakes.

 

Now for that hydrogen distribution infrastructure we need....

 

Put put,

Buffy

[Racoon]

.

 

Now for that hydrogen distribution infrastructure we need....

 

Thats just it.

 

Nice article.

[CraigD]

I read somewhere recently that an unbelievable amount of our air pollution comes from the two-stroke engines in lawnmowers and leaf blowers …

I’ve read the same, and confirmed it anecdotally by briefly running full size auto and small gas motors in a closed garage. Though producing less CO^2, a small motors belch out more visible particles than a car engine a hundred times more massive and powerful, mostly due. 2-strokes (in particular model airplane engines) are especially awful, though small 4-stroke engines are also much dirtier than car engines. This makes sense when one considers that modern auto engines owe their minimal pollutant output to decades of complicated improvements in fuel supply, valve timing, sensors and catalytic converters that are completely absent in most small engines.

Now for that hydrogen distribution infrastructure we need....

I get the impression that when the story says “The researchers' new design is closed” it means it is really a closed system – no H or O in, no H or O out. This is currently practical for small fuel cell systems, which can either be “regenerative fuel cells” that can be operated backwards to separate H2O into H2 and O, or use a separate electrolysis unit on the contained “exhaust” H2O.

 

Last I read about them, regenerative fuel cells were very efficient, but had limited energy capacity, while electrolysis was substantially less efficient than conventional batteries, but had effectively unlimited capacity. In either case, a closed system fuel cell lawnmower would work practically like most current battery powered electric lawnmowers, needing to be recharged from a household electric outlet between uses. The main advantage of fuel cells over batteries in this case would be that, unlike batteries, the electric parts (except perhaps the motor brushes) should last nearly forever.