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Sewage To Be Turned Into H
Anonymous Howard writes "The New Scientist website reports in this article that British scientists are working on a more efficient way to convert sewage and other wet waste into hydrogen fuel. It sounds fairly promising."
Man, when I first read that I was like... I'm livin in Britain now!!
Hydrogen is abundant. However, it's also very reactive and forms compounts rather easily. So we have lots of hydrogen, just not in the form of H2 which is the form that is wanted for fuel.
There once was a fuel researcher from Wales
Who might have had one too many ales...
He said "You might think I'm nuts"
"We can get hydrogen from our butts"
"And fill our gas tanks with our tails!"
What does that say about our geek-ness, or lack of it, when we see "H" and think heroin instead of hydrogen?
It means we know the difference between H, H+, and H2. Hydrogen, like oxygen, nitrogen, and the halogens, is diatomic, meaning that it exists in nature in pairs (Cl2 I2 F2 Br2 O2 H2 N2). In nature, it also exists as positive ions (labeled H+); Bronsted acids give off these. (Water is amphiprotic; that is, it's a weak acid and base simultaneously.)
When I see "H2", I think "hydrogen." When I see "H+", I think "hydrogen ion" and then "there's an acid somewhere around here". Plain "H" by itself is heroin, just like "X" without the "Window System".
Will I retire or break 10K?
If we could turn sewage into energy where I work, our weekly staff meetings could light Las Vegas.
This is exciting - I think that between the public bathrooms and the grease bins, McDonald's will become an energy company, and start giving away food for profit!
Ronald McDonald hereby accepts the Nobel Prize for ending world hunger...
"I am a cipher, a cipher, wrapped in an enigma, smothered in secret sauce" -Jimmy James
This is true. All you need for a hydrogen+oxygen fire is hydrogen, oxygen, and enough activation energy for the reaction (typically provided in the form of a spark or heat from the preceeding reactions). But, before we go any further, let's talk about gasoline. Right now in you car I'm betting you have at the very least 10 gallons of it, and if you just filled up you could have more. Hydrogen as stored for electrical generation would not have oxygen- if you turned on the valve and held your lighter to it you'd essentially be making a bunson burner (or if it's leaking fast enough, a flame thrower). Now, what about gasoline?
Because of gasoline's low flash point (-40 degrees C. or F, your pick), you find yourself with a bunch of flammable vapors in a short period of time. And gasoline burns more slowly than hydrogen, and this is bad in terms of safety. Hydrogen burns up really quickly and is gone, gasoline pesters. Gasoline fires are much more dangerous than hydrogen fires. And we're not even addressing all of the toxic fumes that go along with combustion of gasoline.
In the Hindenburg disaster, all of the hydrogen was gone with a pop. The ensuing fire, flames, and mayhem were the result of the paint- the zepplin was painted with a compound that was intended to reduce drag. Unfortunately, this paint was essentially jet fuel. The Hindenburg disaster serves as more of an argument against petroleum based fuels than against hydrogen.
Of all the problems with hydrogen, safety is not one of them. It's safer for people directly, and it's safer for us and the enviornment in the long run.
As for your question about efficiency, obviously 20% efficiency means you harness 20% of the total energy that is in the fuel source. Getting 20% more out than what you put in would be a violation of the first law of thermodynamics.
-bugg