[wjbond7]

I am not a chemistry student however, I was wondering if someone could help answer some basic chemistry questions for me. I am doing research on energy management and need verification on some chemistry processes and information.

1. If CO₂ emissions could be captured and reused in consumer products - would it be the same as using manufactured CO₂? Are we talking about the same chemical used to make soda pop? Could that happen?

2. If CO₂ emissions could be captured could it be converted into carbon black or soot or graphite? or dry ice?

3. I've read CO₂ dissolves into carbonic acid. How does a gas "dissolve" and what can carbonic acid be used for?

I would appreciate any enlightenment. Thanks in advance.

[Yggdrasil]

1.  It should be the same assuming you could efficiently capture and purify the carbon dioxide from the air.  Carbon dioxide, the same greenhouse gas that everyone is worried about, is used to carbonate soft drinks.  However, compared to manufactured carbon dioxide, I would think that the recaptured and purified carbon dioxide from emissions would be much more expensive to obtain and therefore unsuitable for consumer products.

2.  They could possibly be converted to another form, but these processes take energy and are expensive.

3.  Most gases dissolve in liquids just like solids (e.g. table salt or sugar) dissolve in liquids (however, there are some notable differences, for example, the dependence of solubility of temperature).  Fish respire, for example, by "breathing" the dissolved oxygen in water.

Carbon dioxide is special, in that, in addition to dissolving in water, it also reacts with water to form carbonic acid.

CO₂ + H₂O --> H₂CO₃

A salt of carbonic acid, sodium hydrogen carbonate or sodium bicarbonate (NaHCO₃) is the main ingredient of baking soda.  In the human body, dissolved CO₂ in the form of carbonic acid, helps to keep the blood's pH fairly constant.

[movies]

1.  It should be the same assuming you could efficiently capture and purify the carbon dioxide from the air.  Carbon dioxide, the same greenhouse gas that everyone is worried about, is used to carbonate soft drinks.  However, compared to manufactured carbon dioxide, I would think that the recaptured and purified carbon dioxide from emissions would be much more expensive to obtain and therefore unsuitable for consumer products.

I agree that the reclaimed carbon dioxide would probably be a lot more expensive, but that's not necessarily a deal breaker.  We know that in general recycled materials are more expensive than freshly made materials (e.g., glass, aluminum cans).  Just because it's more expensive to reclaim them doesn't mean that it's not worthwhile.  You have to consider the effective savings in minimizing greenhouse emissions as well.  It would certainly require an investment, but if you are using something instead of throwing it away there is probably some benefit to be had.

[ATMyller]

2. Dry ice is one of the byproducts when manufacturing liquid nitrogen and liguid oxygen, but the starting material (air in this case) only has <0.04% of CO₂ in it. So the method is not viable for large scale CO₂ capture. Also dry ice vaporizes and CO₂ leaks back in to the atmosphere quite rapidly if not storaged in gas tight container.

We know that in general recycled materials are more expensive than freshly made materials (e.g., glass, aluminum cans).

Actually it's quite the opposite. Making an aluminum cans from recycled aluminum only involves melting and malleating the metal. Whereas making it from ore requires mining, refining and electrolysis with total energy consumption being 20 fold compared to the recycled one.

[movies]

Really?  Maybe I heard that the cost was higher with some other recyclables.  Plastics maybe?