revesible hydrocarbonic reaction

[rodge]

I have learned that almost all chemical reactions are reversible. if so then why isn't any effort put into the reversal reaction of hydrocarbonic combustion? If this reaction is feasible, shouldn't it be implicated? millions, even billions of dollars would be saved. fossil fuels would become a renewable resource. global warming could be lowered. economies would prosper.

[hermanntrude]

when a reaction is reversed, the sign of the enthalpy change is also reversed. What this means is that if a reaction gives a lot of energy out in the form of heat (like a combustion reaction does), then the reverse reaction requires that much energy to happen. Sometimes in reality it takes a lot MORE energy because of other factors too.

[rodge]

i understand that in order to reverse the reaction, it would need to be extremely cool and the fuels would have to be pure, but these would theoretically be easy hurdles to overcome. what i am asking is WILL it be done, not could it be done, and when?

Edited December 3, 2008 by rodge

[hermanntrude]

the easiest method to reverse combustion is to be a plant. Plants take water and carbon dioxide and make sugars from them... sugars arent hydrocarbons but the plants also make a variety of hydrocarbons from the energy provided by the sugars

[rodge]

well you say this is the easiest method. does that mean there are other methods? SURELY there is a way. even if it is primitive, with the rate of technological advances, an adequate and effective method could be rendered in the next few decades.

[iNow]

Okay, so we have carbon scrubbers on our submarines and on the space shuttle and in the space station. Why don't we scale up production of these bad boys a few orders of magnitude, power them with solar panels, and plop them in large density across the planet?

 

It's just an idea, and I'm sure there are problems with it, but what are they? Identifying a problem is the first step in solving it...

[hermanntrude]

of course there's a method. The trouble is that the laws of the universe do not permit us to re-make hydrocarbons for less energy than we get out of burning them. If it takes more energy to make hydrocarbons than we get from burning them (and it MUST... it's a law of thermodynamics) then there's no point in doing it.

[John Cuthber]

You can make a carbon scrubber for the air in a submarine, but in doing so you gennerate a lot more CO2 than the scrubber will ever absorb.

Similalry it's possible to reverse the burning of coal, but the energy needed is so large that it would require you to burn more coal and thus generate more CO2 than you got rid of.

[iNow]

Hence the point of powering the scrubber with solar. What am I missing, exactly?

[rodge]

but what about the laws of equilibrium?

[farmboy]

Hence the point of powering the scrubber with solar. What am I missing, exactly?

 

 

If you could get enough power from the solar panels to convert the CO2 back into the fossil fuels, then why use the fossil fuels in the first place? It would be easier, and far more efficent, to just use the power directly from the panels.

 

 

but what about the laws of equilibrium?

 

What about them? All reactions are reversible, but that doesn't meant they are easily reversible.

[iNow]

If you could get enough power from the solar panels to convert the CO2 back into the fossil fuels, then why use the fossil fuels in the first place? It would be easier, and far more efficent, to just use the power directly from the panels.

 

I think I see the source of the confusion. I'm not talking about efficiency, and I agree that it's much better to just use solar panels as the primary source of power, instead of wasting a bunch by converting it over and over into other forms. However, I'm talking about a potential way to remove the excess carbon from the atmosphere.

 

CO2 causes warming. CO2 stays in the atmosphere for centuries. We keep putting more CO2 into the atmosphere.

 

While we convert our society off of fossil fuels, we should work to find ways to pull the excess carbon from the atomosphere, especially since we keeping adding more and more every single day.

 

Ergo - the idea I shared above about solar powered carbon scrubbers in large concentrations across the face of the earth.

 

Would it work if it could be manufactured and put in place?

[farmboy]

I think I see the source of the confusion. I'm not talking about efficiency, and I agree that it's much better to just use solar panels as the primary source of power, instead of wasting a bunch by converting it over and over into other forms. However, I'm talking about a potential way to remove the excess carbon from the atmosphere.

 

CO2 causes warming. CO2 stays in the atmosphere for centuries. We keep putting more CO2 into the atmosphere.

 

While we convert our society off of fossil fuels, we should work to find ways to pull the excess carbon from the atomosphere, especially since we keeping adding more and more every single day.

 

Ergo - solar powered carbon scrubbers in large concentrations across the face of the earth.

 

Would it work if it could be manufactured and put in place?

 

It is hard to say, the science is good, but I'd imagine it would be more of a question of politics/economics as to whether any such plan could be implemented. People can't even agree on whether or not global warming is happening, so it seems unlikely that they anyone would be willing to put money into such a project. That is just pure speculation though.

[Theophrastus]

As everyone has mentioned, the energy required to produce the desired effect, would be huge, and this is the ultimate obstacle. You see, while it is quite easy to think of this from an outside perspective, in thinking of what's right, business and industry looks towards what is profitable. This is why peoples' very lives are exploited in developing countries, by companies. This is why certain types of green technology that is possible is not implemented. These concerns, to a certain degree, are understandable. However, unless there is a way that is profitable, a use for the carbon dioxide, that is then captured, I seriously doubt any large scale developments in the future. I've posted a link below, showing an interesting method of transmitting CO2, a by- product of fossil fuel and coal burning, to other industrial uses.

 

 

This is why the recycling of metals has become commonplace so quickly, because, the process of recycling these metals, is far more energy efficient, that simply extracting them from their ores. The point I stress is that business, generally speaking, will lean towards what is profitable, and what is economic. And in respite of that rather melancholly note, I have a lovely quote for martin luther king:

 

"Cowardice asks the question: Is it safe?

Expediency asks the question: Is it politic?

Vanity asks the question: Is it popular?

But conscience asks the question, is it right? And there comes a time when one must take a position that is neither safe, nor politic, nor popular, but because conscience tells us it is right."

[hermanntrude]

theophrastus, please don't go digging up old threads unless there's something useful to say. The last post in this thread was nearly a year ago.

[Theophrastus]

Sorry, simply felt a little under the weather, and decided to look through any threads that were either unanswered, or seemed interesting. Yes, I know, I must find something to do... wow, I feel like a six year old! (No reasoning behind it, I simply do) (the following has absolutely no relevance to the thread in question whatsoever, does it?) Ah well...

Edited March 21, 2009 by Theophrastus
addition of a necessary exclamation mark, to display childish fascination with grammar and punctuation

[max.yevs]

If you could get enough power from the solar panels to convert the CO2 back into the fossil fuels, then why use the fossil fuels in the first place? It would be easier, and far more efficent, to just use the power directly from the panels.

 

fossil fuels have a higher energy density than batteries. batteries, so far, are bulky and need to be recharged much more often. And cars surely cant go 60mph with a solar panel strapped to their top!