| Re: Chemistry of CO2 Neutralisation - Can weight be used as an indicator of scruber l I had a second look at the scrubber quantitative situation. This can be used as a guidance and might also be proved to be wrong. Here we go:
Sofnolime contains more than 70% of its weight in Ca(OH)2.
Therefore for a 2,5 Kg sorb (axial scrubber of Meg) there is more than 1750g of Ca(OH)2.
The mole of Ca(OH)2 is 74g. So we have in the scrubber 23 moles of Ca(OH)2.
Each mole of Ca(OH)2 can neutralise 1 mole of CO2. Since the mole of CO2 is 44g, theoretically we would expect that 23 X 44g of CO2 would be added to to weight of the scrubber if the efficiency of the scrubber is 100% (taking into account only the Ca(OH)2 which is the predominating base).
That is approximately 1 Kg of CO2.
Let's suppose that on average a diver produces 0,9 litres (1,77g) of CO2 per minute.
Theoretically again the scrubber would be good for 570 minutes under these CO2 production rates.
However since the scrubber is in the form of pellets one would expect that its efficiency is not 100%. ISC clearly states that the scrubber is good for 3,5 hours. We then assumpt that the scrubber efficiency is 210 minutes divided by 570 minutes (approximately 35%).
With 35% efficiency i would expect that 35% of 1Kg of CO2 could be neutralised in the Meg's axial scrubber. The is approximately 365g.
I would therefore assumpt that at the end of the scrubber life it will weight 365g more compare to its initial weight.
Assumption #1: All the water that is being produced inside the scrubber remains inside the scrubber
Assumption #2: No water from other sources is entering the scrubber.
Please note that the above are just assumptions and need to be modified according to actual findings from real experiments.
proposal: Check the scrubber weight after 3,5 hours of use at more or the less oxygen consumption of 1 LPM and compare it with the calculated expected weight increase of 14,5%. (365g over 2500 g).
Last edited by diveoceanos : 2nd April 2008 at 18:45.
|