CO2 absorption rate in water

[sspence]

trying to find out the absorption rate of carbon dioxide in water under pressure.
I have a air stream at 500SCFM with some CO2 (i.e. 15%) and trying to calculate how much CO2 will be absorbed if ran thru a Water scrubber (15% CO2 goes to 5%).
I have the solubility value at atmosphere but know absorption increases under pressure.

 

[m777182]

The rate of adsorption of CO2 in water is governed by a diffusion of gaseous CO2 so that the interface area gas/solid is crucial.The maximun attainable concentration in water is given by Henry's low (temperature and pressure related). Particular data you can find in Perry's Chemical Engineer's Handbook or elsewhere.If you can afford an alkaline solution then much more effective adsorption with chemical reaction takes place.
m777182

 

[25362]

At 30^oC, Henry's constant for CO₂, H = 1900 atm. If Henry's law is applicable: x = Py[÷]H

where

x= mol fraction in water
Py = partial pressure in gas (e.g., total pressure [×] mol fraction), atm

CO₂ reacts with water as follows:

CO₂(gas)[↔]CO₂ dissolved; + H₂O[↔]H₂CO₃[↔]H⁺ + HCO₃^-​

Even at high pressures you'll find you need a large liquid flow rate. As m777182 says, if you add something to the scrubbing solution that will consume H⁺, such as an alkali, much less water can be used.