Tuesday, September 11, 2007

Homer the Physicist

While this story about burning salt water is really exciting and everything, I’m going to go with Homer Simpson on this one: “In this house we obey the laws of thermodynamics!”

Quick science lesson for those of you not skilled in the art (as they say in patent literature): for some time mankind has known that you can split apart the molecular bonds of salt water to release hydrogen. This is most commonly done via electrocells to make caustic soda (NaOH), which has a variety of uses in the chemical industry. Literally millions of tons of NaOH are fabricated every year this way.

Don’t just believe me; it’s well-explained on wikipedia.

The problem here is that hydrogen and oxygen are bound pretty well in the H2O molecule, so in order to force them apart you have to apply some kind of energy. Thermodynamics being what it is (a harsh taskmaster), you can’t get more energy out than you put in. And typically, you get less.

Probably the best you could hope to do would be to use a radio-wave generator to evolve hydrogen that you could burn to make enough energy to power a radio-wave generator that would be able to evolve hydrogen…

More likely, you’d get enough power to run about 40% of the radio-wave emitter, and then you’d have to supply the rest by plugging it into the wall and using power from a fossil-burning plant.

This is maybe interesting on the level of being able to replace electrodes in electrocells. I’m not skilled in that, so I can’t comment on it. But it’s probably not got much use as power generation or as desalination (I would expect to get 1 chlorine ion per hydrogen and thus contaminate the water).

It would really help if, before breathlessly putting this front-page on Yahoo, they’d maybe pass it by a scientist or something.

PS: In Cleveland, they mastered burning fresh water back in the 60's. Top that, science geeks!