Posted on 12/06/2001 8:53:34 AM PST by aculeus
Scientists in Japan have found a more efficient way to extract hydrogen, the ultimate 'green' fuel, from water. They have developed a material that uses sunlight to break water molecules into their constituent elements of hydrogen and oxygen1.
The material is not yet efficient enough to be commercially viable, but its inventors believe that it can be improved. If they are right, hydrogen may soon be on tap just like natural gas.
Hydrogen burns in air without producing the sooty pollution and greenhouse gases associated with fossil fuels. The element can also power fuel cells to generate electricity. Such fuel cells can power emission-free electric vehicles.
Unfortunately, water is reluctant to give up its hydrogen. Electricity can split water, but electricity is mainly generated using polluting and nonrenewable technology.
Several 'photocatalysts' will split water quite efficiently using ultraviolet light. But this squanders most of the Sun's energy, which lies in the visible range. Visible-light photocatalysts, on the other hand, have tended to be either unstable, decomposing with prolonged use, or bad at splitting water.
Zhigang Zou of the National Institute of Advanced Industrial Science and Technology in Tsukuba, Japan, and co-workers have developed a photocatalyst that seems to be very stable, showing no evidence of degradation after extended use. It is not terribly efficient - over 99% of the light energy is wasted rather than used to split water - but this is respectable when compared with the competition.
The material, like the majority of visible-light photocatalysts, is a metal oxide, which generates hydrogen and oxygen when immersed in water in sunlight. The oxide contains indium, nickel and tantalum; the efficiency depends on the amount of nickel in the material.
Zou and colleagues believe that they can improve the efficiency by increasing the surface area of the photocatalyst - making it porous, for example, or grinding it into a fine powder - and by further tinkering with the chemical composition.
[References provided at the link.]
Agree. However if the technology were portable, you could drink Perrier and go nonstop on your SHT/Ginger/IT scooter. Just give IT a sip occasionally:)
Nor does it have to be. Cover enough of the Arizona desert with this stuff, and you'll be able to generate a bottom-load of hydrogen.
I'm guessing that if this ever works, it'd be for fuel cells -- and given that this process is also a dandy oxygen generator, it would be self-restoring.
The downside, of course, is still the difficulty of delivering and storing liquid hydrogen and oxygen.
Not to mention the difficulties associated with purifying enough water to make this worthwhile.
Since many wars are fought over land and resources, suppose everyone had access to cheap and unlimited powers. How would that change things?
For example, if energy was cheap enough, you could extract gold and other precious metals from sea water.
How would the balance of power change?
You better watch, eric,.... long pause
[Excuse me, just had to hoist my fat-a** away from keyboard to get refills on coffee and doughnuts]
....anyway, you better watch who you're addressing... :)
Cover enough of the Arizona desert with this stuff
Talk about environmental degredation! I'd rather build 2 or 3 Nuclear Power plants to generate hydrogen from H2O. Nuclear power is still the cleanest, safest, cheapest form of energy.
Several 'photocatalysts' will split water quite efficiently using ultraviolet light. But this squanders most of the Sun's energy, which lies in the visible range.
Who cares? How much does sunlight cost? Is it in short supply?
IMHO the world would be drasticall changed, but not overnight. The first (wide-spread) commercial use of this would be on the electrical grid. This would, over a few years, replace fossile fuel power generating plants. The coal industry would be the first to be hit. Although coal-fired power plant are a lot cleaner now, they are still the dirtiest. Next would be oil and natural gas-fired power plants. With more and more of those plants being converted world wide, the price of crude would continue to drop as less and less of our Electricity needs are dependant on oil.
Gasoline powered cars would still be as popular as they are now, perhaps even more so since there would be a lot more oil on the open market. Sure, hydrogen would be "affordable" but $.50 a gallon gas would spur lots of SUV sales. After about 10 years the technology and infrastructure for hydrogen would be developed enough to begin building cars designed to run on hydrogen and start to re-fit the older gasoline engines. Expect a big surge in businesses providing that service.
A decade later the middle east would be a real mess. The only reason the world tollerates that region and it's problems now is because they they supply 40% of the worlds oil, and if we don't need oil, the rest of the world could care less about them. With middle east nations seeing their days of glory and power about to end, the region would most likely come apart at the seams. After that, who knows.
Purifying the water is the easy part. Covering enough square miles of the Earth with the photocatalyst to produce the requisite amount of fuel will be difficult. I'll try to whip up an approximate calculation , but I suspect it will be in the order of several thousand square miles.
OK, the preliminary calc presumes a 10 hour day for reaction time. Then assuming the article stated 1% efficiency, the area required (assuming no clouds, storms, breakdowns, etc) to produce enough hydrogen to replace petroleum (not Nat gas or coal, just oil) is about 42,480 square miles for the US.
Maybe viability is a wee bit further out.
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