reaction consuming CO2

[gio1]

A sealed tank is filled with gaseous CO2 at 200F and 200Psi.
Is there any substance which if introduced in the tank could react with CO2 and reduce the pressure?

Thanks

Gio1

 

[dcasto]

ice

 

[gio1]

unfortunately ice is out of question for other reasons. Would Mg react with gaseous CO2?

 

[25362]

Yes. Just Google for magnesium and carbon dioxide and you'd get plenty of information.

 

[gio1]

Yes, I have looked but all I found were examples of magnesium reacting with solid CO2 (dry ice). Would the same reaction occur if the CO2 was in gaseous state? (Perhaps it would be slower?)

 

[25362]

Magnesium oxide could be better to absorb gaseous CO₂. See, for example,

Absorption of carbon dioxide gas contained in exhalation of inhalation anesthetic subject Document Type and Number:United States Patent 5390667 Link to this page:

http://www.freepatentsonline.com/5390667.html

 

[unclesyd]

Lithium Hydroxide is still being used in Space flights.

You could use a reactive amine like the one I'm familiar with, Hexamethylene Diamine. HMD reacts readily with CO2 to form HMD carbonate.

 

[gio1]

I guess you refer to
2 LiOH + CO2 ? Li2CO3 + H2O

But would the above reduce the pressure in the sealed tank? (water vapour would replace CO2 - is that more dense?)

Thanks
Gio1

 

[gio1]

I meant
2 LiOH + CO2 --> Li2CO3 + H2O

My concern is that H2O (vapour) is being produced which could rise the pressure - is that true?

 

[unclesyd]

Your answer will require a little Thermo calculations to determine what happens to the H2O.


Here is a very good treatise on CO2 control by Dr. James E. Atwater. The first is the LiOH reaction and the second is about the all the methods used for reduction of CO2 in an enclosed environment. There may be some other systems if the human factor doesn't enter the picture.

http://oregonstate.edu/~atwaterj/lioh.htm

http://oregonstate.edu/~atwaterj/co2.htm

 

[Compositepro]

Sodium hydroxide will also work and is cheaper and more readily available. However, some water is probably also required to get the reaction to proceed.

At 200F the vapor pressure of water is less than 15 psia - far less than 200 psi.