WHO DIES, MAN OR PLANT? THE SEQUAL
This time with text. Dont know what happened last time.
Almost all of the new technology to replace fossil fuels are pointing toward hydrogen conversion. To the best of my knowlege the principal is to pass water over a catylist and free a Hydrogen atom to burn. Then when the HO exits it immediately picks up a new Hydrogen atom from the air and becomes H2O again. This is all well and good but where does Hydrogen come from? How readily replaceable is it? When Hydrogen burns is it destroyed? If the tens of millions of fossil fuel burning engines convert to Hydrogen will there be enough? Where will the carbon compounds that are needed for photosynthisis come from to support plant life at its current level? Can man survive on lesser amounts or no Hydrogen? Could we talk without sounding like Minnie Mouse on speed?
Whos got an answer, or even a good guess? Its been too long since high school chemistry! I would even settle for a SWAG
Almost all of the new technology to replace fossil fuels are pointing toward hydrogen conversion. To the best of my knowlege the principal is to pass water over a catylist and free a Hydrogen atom to burn. Then when the HO exits it immediately picks up a new Hydrogen atom from the air and becomes H2O again. This is all well and good but where does Hydrogen come from? How readily replaceable is it? When Hydrogen burns is it destroyed? If the tens of millions of fossil fuel burning engines convert to Hydrogen will there be enough? Where will the carbon compounds that are needed for photosynthisis come from to support plant life at its current level? Can man survive on lesser amounts or no Hydrogen? Could we talk without sounding like Minnie Mouse on speed?
Whos got an answer, or even a good guess? Its been too long since high school chemistry! I would even settle for a SWAG
posted by red label @ 7:03 AM
4 Comments:
At November 18, 2005 at 12:23 PM,
uncaring _chimp said…
If mankind is really serious about "sustainable energy", the answer is simple: manufacture engines that run on bullshit. I'm confident there will never be a shortage.
Lois
At December 6, 2005 at 2:41 PM,
James said…
Red,
I'm glad you asked. Let me clarify the basic mechanics of the "hydrogen economy".
The hydrogen for hydrogen-burning engines may be produced in at least two ways. One way, that still depends on fossil fuels or biologically produced hydrocarbons (methane, CH4, from cows' digestion, for example), is to catalytically separate the hydrogen atoms from the carbon atoms. It takes energy to perform this process; this energy may come from burning a portion of the hydrocarbon with oxygen (O2) from the air, or from some external electrical energy source. What one is left with is hydrogen gas (H2), and carbon. The other way to obtain hydrogen gas is by electrolysis of water (H2O). Water, with a certain amount of dissolved electrolyte (salt) to aid in electrical conduction, is subjected to an electric potential (voltage). This breaks down the water molecules, resulting in the production of oxygen gas (O2) at one electrode, and hydrogen gas at the other. The oxygen can either be collected, which is more likely, or released into the atmosphere.
When hydrogen produced by either process is burned in an engine, it reacts with oxygen taken from the air, to form water. (Hydrogen used in a more efficient fuel cell, instead of in a combustion engine, also combines with oxygen, and the ultimate product is the same, water.) If water is the original source of the hydrogen, you can see that this is a back-and-forth process that can be repeated indefinitely without ever depleting the supply of hydrogen. The only limit on the quantity of hydrogen one can produce is the amount of electrical energy available to separate it from water. This electrical energy, if hydrogen fuel is to be a sustainable option, must itself come from a sustainable source -- wind or solar power are some examples.
I'll answer a few of your other specific questions now:
The carbon compound required for photosynthesis is carbon dioxide, CO2. This comes from many sources: animal respiration, wildfires, volcanic eruptions, fireplaces, and so forth. Plant life flourished for eons on this planet without the help of CO2 from internal combustion engines, so don't worry that burning hydrogen instead will starve them for CO2.
Man does not require molecular hydrogen (H2) to survive. There is a negligible amount of it in the atmosphere. We DO require hydrogen in its compounds, such as fats, carbohydrates, water, and so forth. Hydrogen is a major component of all our cells. We get it through what we eat and drink; we do not breathe hydrogen.
At December 20, 2005 at 7:12 AM,
red label said…
Thank you James! Nice to see that someone is watching and that not all of my musings are for naught. However isnt the symbol for the hydrogen molecule H and not H2?
At April 4, 2006 at 9:37 AM,
James said…
Hydrogen is one of those gases that form diatomic molecules, meaning made of two atoms. That's why the gas is always written "H2" (the "2" should be a subscript ... don't know how to do that in HTML). Same with O2, N2, Cl2 (chlorine), etc. Helium, neon, xenon -- these are monatomic gases, and so are written He, Ne, Xe.
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