I apologize, I gave a knee-jerk reaction - I'll research what you said, and get back to you if I think I have a leg to stand on

 

Theoretically No. Since energy is never created or destroyed it cannot take more energy to break apart water into hydrogen and oxygen than you can get from recombining hydrogen and oxygen. However in practice you lose usable energy.

To make hydrogen using electrolysis, not all of the electricty goes into breaking up the molecules of water. You lose some to heat in the wiring because of electrical resistance. Also some of the energy heats up the water. But if you added up all the heat losses and the ammount of energy theoretically required to split the ammount of water into hydrogen and oxygen, you would find that this ammount was equal to the ammount of electrical energy you used to produce the hydrogen.

When you recombine the hydrogen with oxygen, in an ICE for example, you get rotational energy and heat. In an ICE you need a radiator because the engine is only approximately 25% efficient. So for every horsepower that comes out of the engine due to crankshaft rotation, three horsepower come out of the engine in the form of heat. If you could make an ICE with an efficiency of 100%, then your car would have no need for a radiator. However, this is not possible. It is not even a theoretical possibility. If someone could build a perfect internal combustion engine, it would still be only about 60% efficient. This is because of the thermodynamic laws that govern how an ICE works.

So lets assume that only 10% of the energy is lost as heat when you produce hydrogen. That means that the production process is 90% efficient. Now if the ICE is 25% efficient, this means that the total efficieny, which is equal to energy out divided by energy in, is equal to 90% * 25% which is equal to approximately 23%. The other 77% of the energy is lost as heat which is wasted. But still, if you add up all the heat output in the production process, plus the heat lost from the engine, plus the energy output from the crankshaft, this would be equal to the electrical energy used to make the hydrogen in the first place.

So theoretically if you could make the hydrogen production process 100% efficient, and "burn" the hydrogen with 100% efficiency, then every bit of the energy used to produce the hydrogen would become useful energy when you used the hydrogen.

Energy used in production = Useful Energy Attained + Energy "Wasted"

But the Energy "Wasted" is not actually lost. It is just not in a form useful to us, namely heat.

 

Ok kewat, here's my answer.

From dictionary.com
Theory: An assumption based on limited information or knowledge; a conjecture.

There are 6 definitions for 'Theory'. This one applies to this discussion. In post #5 of this thread you made mention of the difference between fact and theory. I am simply pointing out that two of your assumptions are in fact theory. 1. We don't have enough information to know that we are running out of oil. To know that we would have to know A. how much total oil there is on the Earth, and B. How fast is that supply being replentished. We do not know either item. Therefore the statement that we are running out of oil is conjecture based on limited information.

As for the second theory about ruining the Earth, yes there are locations that have been polluted but you yourself mentioned superfund sites. There are superfund sites that have been cleaned up. You also mentioned that Hiroshima was cleaned up. So from your statements, even if we spoil a location, we can clean it up. I never said it nature would clean it up by itself and I never said we wouldn't step up to clean up our own mess. When one of those sites gets cleaned up, what happens to the 'stuff' they remove. There must be some way of treating or handling it to make it neutral to the environment. There is no 'Toxic Waste' element on the periodic table.

Nowhere in any of my discussions did I state that your theories were wrong. Nor did I suggest a prudent course of action based on those theories or any other. You brought up the subject of theories. I simply pointed out that you were putting forward theories yourself. This becomes important because when an idea is a theory, it COULD be wrong. If you accept that it could be wrong, you look for alternate ideas. It's called 'thinking outside the box' and I've made a lot of money by being able to do it. Many times we invest so much of ourselves in our theories, we are not willing to see them disproven or challenged. This is true with any discussion be it energy, political or religious. But if we can step away from an idea and realize it's limitations, that is the first step to seeing other possibilites.

 

Enough that in 20 years the global pollution problem won't be global warming. It will be 'global wetting'!

 

I agree with all you say - except for one thing:

Your "do nothing" stance.

Why do nothing? Why not do something about it now, if we even THINK something could happen?

Global warming/et al is not something we can "clean up" - to remove all the excess carbon dioxide and other pollutants would require a project on such a massive scale that it would be impossible.

Ever hear of "terra-forming" ??? That's the process of taking a hostile planet or asteroid and producing enough oxygen-rich atmosphere so that humans, animals and plants can live there. That's basically what we'd have to do - terra-form our own planet. Foolishness.

Again, just because they are THEORIES does not mean we should not act NOW to curtail the effects.

 

Better read my posts again. Nowhere did I advocate any course of action. I did not suggest standing by nor did I suggest alterate fuel methods. This is because I wasn't discussing actions. You said:
"It doesn't matter when we run out of oil - we will eventually".
I simply asked you to proove that statement, to which you replied:
"Theories?

We will run out of oil eventually."

Restating your original argument is not supplying proof. Had this been a refereed debate you would have lost at this point. I might agree with your statement. I haven't revealed that yet.

Later, in post #12 you hit the nail on the head when you stated:
""Let's wait until it's PROVEN we can run out of oil" - how? When it finally runs out?"
Given this particular situation, that may actually be when we find out for sure. Until that actually happens, your original statement will be just a theory. Some people will treat it as gospel, but there will always remain the possibility that it is wrong.

Do I think we shouldn't continue to explore and develop other energy sources? No. Do I think hydrogen will be some sort of miracle, silver bullet to solve all our engery needs? No. It takes too much energy to free it from water, and why would you want to add another refining step to get it from oil when you can just burn the oil.

The bottom line is still we use petroleum because it is the cheapest, most efficient method of getting energy. Until it's not, we can investigate and develop alternatives, but don't expect them to take off. It's more a matter of market forces than conspiracies.

 

I'm a patroleum pig as much as anyone. I don't like hybrid cars, electric cars, or tofu for that matter. But waiting until we are completely out of oil to start exploring new energy sources would be a very costly blunder. Now is the time (if not already a little late) to start moving towards other sources of fuel.

 

That's not true. You get the same ammount of water that you used to make the hydrogen.

 

Wick246, We already ARE moving toward other sources. And we will continue to do so. But they will not gain widespread acceptance until they can be competative in the market. To try to force any other course (ie legislate alternative fuels into use) would not be the best course of action.

 

Not if you get your hydrogen from petroleum. Which is the most efficient source to use for hydrogen.

 

By that argument you should stop burning oil in any form because all the hydrogen in any hydrocarbon chain forms water.

direct burning of hydrocarbon chains:

2CnH2(n+1) + (3n+1)O2 ==> 2nCO2 + 2(n+1)H20 + energy

steam reformation of hydrocarbon chains to produce hydrogen:

2CnH2(n+1) + 4nH20 ==> 2nCO2 + 2(3n+1)H2

subsequent burning of hydrogen:

2H2 + O2 ==> 2H20 + energy

If you scale this equation properly you get:
2(3n+1)H2 + (3n+1)O2 ==> 2(3n+1)H20 + energy

now add the steam reformation and scaled hydrogen burning equation:

2CnH2(n+1) + 4nH20 ==> 2nCO2 + 2(3n+1)H2
+ 2(3n+1)H2 + (3n+1)O2 ==> 2(3n+1)H20 + energy
_________________________________________________

2CnH2(n+1) + 4nH20 + 2(3n+1)H2 + (3n+1)O2 ==> 2nCO2 + 2(3n+1)H2 + 2(3n+1)H20 + energy

now if we reduce this equation we get:

2CnH2(n+1) + (3n+1)O2 ==> 2nCO2 + 2(n+1)H20 + energy

Now if this equation looks familiar it is because it is the same as the direct burning of hydrocarbon chains.

2CnH2(n+1) + (3n+1)O2 ==> 2nCO2 + 2(n+1)H20 + energy

And also the argument that we would have a problem with global wetting is not accurate either.

In 2002 the world daily average consumption of gasoline was approximately 20,185,200 barrels per day. A barrel holds 42 US gallons. A gallon of gasoline weighs approximately 6 pounds. Which is the same as about 2700 grams per gallon. Now I am going to assume that gasoline can be thought of as 100% octane to simplify this calculation. 6.02 x 10^23 molecules of octane weigh approximately 114 grams. By dividing 2700 by 114 and multiplying this by 6.02 x 10^23 we find that there are approximately 140 x 10^23 molecules of octane in a gallon of gasoline. Now using the equation for the burning of octane:

2C8H18 + 2502 ==> 16CO2 + 18H2O

This means that for every octane molecule burned we get 9 water molecules.

So doing some math:

20,185,200 barrels/day x 42 gallons/barrel x 140 x 10^23 molecules of octane/gallon x 9 molecules of water/molecule of octane

This means that the world produces approximately 10^35 molecules of water every day. That is a 1 followed by 35 zeros.

Now to figure out how many gallons that is. One gallon of water weighs approximately 8.8 pounds. That is the same as 4000 grams. 6.02 x 10^23 molecules of water weigh 18 grams. So if we divide 4000 grams by 18 and then multiply by 6.02 x 10^23 we find that there are approximately 1338 x 10^23 molecules of water per gallon.

So now some more math:

(10^35 molecules of water/day) / (1338 x 10^23 molecules of water/gallon)

This means that the world produces approximately 747,384,155 gallons of water per day by burning gasoline.

So to answer an earlier question. If all the worlds cars burned either hydrogen derived from gasoline, or gasoline. In 10 years they would produce about 3,000,000,000,000 gallons of water!!!!

But now compare this to the ammount of water in the worlds oceans. There 1,370,300,000 km cubed of water in the oceans. One kilometer cubed contains approximately 258,064,516,129 gallons. So the oceans contain about 3.5 x 10^20 gallons of water!!!!

So in 10 years all the worlds cars burning either gasoline of hydrogen derived from gasoline would produce the same ammount of water as about .000000848% of the worlds oceans. That is less than a 1 millionth of a percent increase in the ammount of water in the worlds oceans. That means that in those 10 years the sea level would increase by about 2 thousandths of an inch.

 

See, global wetting is comming!! Build your boats now!! (You do know I was being facetious with my first suggestion right? But excellent post.)

Here's a slightly more serious request. And we can continue to use octane and assume complete combustion to simplify things. Since you've just proven that burning gas makes more water than carbon dioxide, how much carbon dioxide is produced as a percentage of the CO2 already in the atmosphere?

 

Using some of the math from before and noting that there are 8 molecules of CO2 produced for every molecule of octane burned.

20,185,200 barrels/day x 42 gallons/barrel x 140 x 10^23 molecules of octane/gallon x 8 molecules of carbon dioxide/molecule of octane

This means that there are 9.5 x 10^34 molecules of carbon dioxide produced by burning gasoline every day. 6.02 x 10^23 molecules of carbon dioxide weigh 44 grams. So this means about 6,943,522 metric tons of carbon dioxide are released into the air every day from burning gasoline. So in 10 years 25,343,855,300 metric tons of carbon dioxide will have been released into the amosphere. As of 2004, there are 2.7 x 10^12 metric tons of carbon dioxide in the atmosphere.

So in 10 years the ammount of carbon dioxide in the atmosphere will have increased by about 1% just do to automobiles burning gasoline, or gasoline derived hydrogen.

The following graph shows the actual ammount of carbon dioxide in the atmosphere for the past fifty years or so. A couple things to note is that the ammount of CO2 is increasing. The yearly spikes and dips are because there is more plantlife in the northern hemisphere than in the southern hemisphere, so during the summer in the northern hemisphere more carbon dioxide is absorbed by plants and turned back into oxygen. The yearly peaks in atmospheric CO2 are in May and the yearly troughs are in October.



Here is another graph that shows the global emissions of CO2 since 1800.

 

Cool. I've seen that first graph before. Couple of things to note about that graph.
1. From en.wikipedia.org "The initial carbon dioxide in the atmosphere of the young Earth was produced by volcanic activity"
2. Also from wikipedia, the caption for that graph. "Atmospheric CO2 concentrations, measured at Mauna Loa.

Now why would you log data about CO2 from a monitoring station situated on top of the world's largest volcano? Wouldn't the emissions from the volcaon itself affect the readings?

Another thought, according to that first graph, the CO2 levels have increased 17% in the last 40 years. From your calculations, cars would contribute 4% of that total. Might be more productive to concentrate on other reducing other sources.

 

One point in the above graph, as my stats prof used to say, "Any chart or graph that doesn't start at zero on the "Y" axis is misleading". Basically, by starting at 300 (instead of zero) and going to 400 you magnify the "changes" and make things look much worse then the really are in reality.

Show the same graph with a 0 to 400 scale, and the increase is very insignifcant. Also, based on the supposed age of the earth, using a time line of only 40 years gives very meaningless data. This is analogous to driving your car a few feet and using nothing but the fuel consumed in this short distance to state with a high degree of certainty the fuel milage you will get over the next 100,000 miles of driving.

Obviously this doesn't work, and using anything less then many centuries worth of data in describing things like global warming and other environmental trends is only useful when pursuing a particular environmental or political agenda.