Rebreather World - View Single Post - Chemistry of CO2 Neutralisation - Can weight be used as an indicator of scruber life?

jaap · 1st April 2008, 18:02

Quote: (Originally Posted by diveoceanos)

Hello Jaap,

Since there have not been any data so far how one can be so sure that the approach is a waste of time? I would say that the maximum loss in case the outcome will be inconclussive is a waste of time recording several hundreds of dives and analyse them. No?

I see your point and scepticism! This is not definitely without a base but on the other hand is a little dogmatic. Why shall this approach be considered and treated as a taboo? There has not been any suggestion to ignore what is being allready used. And that is manufacturer's reccommendations. We keep doing what we do and at the same time we accumulate some data for the sake of analysis. There is an hypothesis and this hypothesis should be tested to be confirmed or rejected! That's all.

Sotos

OK

My post was perhaps a little hars sounding.

But your "internet chemistry" combined with claims about what is possible and not got me fired up.

Just a few things, before you reject the base catalysis step you could perhaps ponder on these reactions that you posted earlier:

2NaOH + CO2 ----> Na2CO3 (salt) + H20 + Heat
Ca(OH)2 + CO2 ----> CaCO3 + H20 + Heat.

What is you idea on the ballpark solubility of Na2CO3 compared to CaCO3?
What do you imagine happens if Na2CO3 is present thougther with an excess of Ca(OH)2 and some water?

If the strong base has no catalytic function. How do explain the color (pH) shift that occurs over time on the (used)-sorbs that contains an indicator?

Anyway, your weight method will probably give some correlation (But I'm very sceptical to the usefulness). I'm quite certain that even if it would give some useful information it would be strongly linked to the particular scrubber design, how the scrubber is treated and the temperatures.

If you goal is to eliminate the influence of the weight of the water I hope you are very careful not to get tempted to attempt drying the sorb...that could really turn ugly.

Anyway, I think one thing can be certain. If the weight goes down the scrubber is definately dangerous to use...

1st April 2008, 18:02	#22 (permalink)
jaap Normal people worry me Current Rebreather/s: Classic Kiss Other CCR RB80 / Clone Ray Other SCR Home Build Other Rebreather/s: Other CCR RB80 / Clone Ray Other SCR Home Build Join Date: Jun 2005 Location: Stockholm Sweden Posts: 445	Re: Chemistry of CO2 Neutralisation - Can weight be used as an indicator of scruber l Quote: (Originally Posted by diveoceanos) Hello Jaap, Since there have not been any data so far how one can be so sure that the approach is a waste of time? I would say that the maximum loss in case the outcome will be inconclussive is a waste of time recording several hundreds of dives and analyse them. No? I see your point and scepticism! This is not definitely without a base but on the other hand is a little dogmatic. Why shall this approach be considered and treated as a taboo? There has not been any suggestion to ignore what is being allready used. And that is manufacturer's reccommendations. We keep doing what we do and at the same time we accumulate some data for the sake of analysis. There is an hypothesis and this hypothesis should be tested to be confirmed or rejected! That's all. Sotos OK My post was perhaps a little hars sounding. But your "internet chemistry" combined with claims about what is possible and not got me fired up. Just a few things, before you reject the base catalysis step you could perhaps ponder on these reactions that you posted earlier: 2NaOH + CO2 ----> Na2CO3 (salt) + H20 + Heat Ca(OH)2 + CO2 ----> CaCO3 + H20 + Heat. What is you idea on the ballpark solubility of Na2CO3 compared to CaCO3? What do you imagine happens if Na2CO3 is present thougther with an excess of Ca(OH)2 and some water? If the strong base has no catalytic function. How do explain the color (pH) shift that occurs over time on the (used)-sorbs that contains an indicator? Anyway, your weight method will probably give some correlation (But I'm very sceptical to the usefulness). I'm quite certain that even if it would give some useful information it would be strongly linked to the particular scrubber design, how the scrubber is treated and the temperatures. If you goal is to eliminate the influence of the weight of the water I hope you are very careful not to get tempted to attempt drying the sorb...that could really turn ugly. Anyway, I think one thing can be certain. If the weight goes down the scrubber is definately dangerous to use... __________________ My initials: JAAP
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