Bad air originating in tank and not compressor

[Duke Dive Medicine]

For what it's worth and at the risk of being called pedantic, carbon monoxide is not exclusive to combustion. Endogenous carbon monoxide does play a role in metabolism and mitochondrial biogenesis.

The effect of induction of endogenous CO b... [Bratisl Lek Listy. 2014] - PubMed - NCBI
Redox regulation of mitochondrial biogen... [Free Radic Biol Med. 2012] - PubMed - NCBI
Activation of mitochondrial biogen... [Am J Respir Crit Care Med. 2012] - PubMed - NCBI

It's highly doubtful that any of these processes could have produced that much CO, though.

Best regards,
DDM

 

[vincent54]

For what it's worth and at the risk of being called pedantic, carbon monoxide is not exclusive to combustion. Endogenous carbon monoxide does play a role in metabolism and mitochondrial biogenesis.

The effect of induction of endogenous CO b... [Bratisl Lek Listy. 2014] - PubMed - NCBI
Redox regulation of mitochondrial biogen... [Free Radic Biol Med. 2012] - PubMed - NCBI
Activation of mitochondrial biogen... [Am J Respir Crit Care Med. 2012] - PubMed - NCBI

It's highly doubtful that any of these processes could have produced that much CO, though.

Best regards,
DDM

Actually, it is more plausible than a chemical reaction with the rust. We have been going through bad water around Lake Erie, and the algae are the blame. Researching found that CO is commonly produced by certain algae. Carbon Monoxide Production by Algae, so I wonder if the seawater had a algae species that could produce the CO contamination. Far fetched, but so is everyday life. Cheers

 

[grf88]

It would have to be available carbon. An oxide layer would be coating the entire inside surface of tank.

We are not talking about a light coating of rust rather a tank that had been partially consumed by the rusting process. Large pieces were coming out when the tank was banged on the ground. The dive operator thought the rusting was enough that the tank could have ruptured.

 

[vincent54]

The only chemical reaction I know with carbon and water is C + H20--> C0 + H2, and it requires high energy/ heat or radiation to achieve. I know there is an article referenced with corrosion, but haven't been able to access.

 

[grf88]

What would a CO detector do if it tested a tank with very high levels of CO2, and whatever else was happening in the tank? I know some instruments will act weird if used for conditions not included in their design.



Bob
-------------------------------------
Always use the right tool for the job. A hammer is the right tool for any job. Anything can be used as a hammer.

It is an Analox unit. I bump test it daily by breathing into it to check that it is working. If high CO2 levels or moisture content were a factor I would expect the elevated CO2 and moisture levels of the my breath to result in readings higher than 1 ppm.

---------- Post added August 18th, 2014 at 01:22 PM ----------

The only chemical reaction I know with carbon and water is C + H20--> C0 + H2, and it requires high energy/ heat or radiation to achieve. I know there is an article referenced with corrosion, but haven't been able to access.

How about carbon and O2 plus galvanic action. I certainly do not know what caused it but the absence of any CO in all the operators other steel tanks that I tested make the compressor as the source of the CO unlikely although obviously not impossible however the only steel tank with a measurable CO reading was also the tank with salt water in it. Maybe just coincidence but I am not convinced especially when a study has shown elevated levels of CO in a rusting tank.

Doc Harry quoted some parts of the study in this thread:
http://www.scubaboard.com/forums/ta...-cylinder-long-term-storage-fact-fiction.html

 

[vincent54]

C and 02 is combustion. Incomplete combustion gives CO. I doubt if this happened in the tank.

The reason I question the study is it was done along time ago and no one followed it up. The importance of CO production in rusting metal would impact any one who uses steel near salt water. Building an enclosed space that produces CO, for example a ships cabin, would be dangerous. CO is cumulative and low dose chronic exposure would at some point show itself.

If someone has a copy of the article in it's entirety , it might clarify how the CO is produced. As with many studies, initial findings are just that. There needs to be confirmation and repeat-ability.

 

[grf88]

C and 02 is combustion. Incomplete combustion gives CO. I doubt if this happened in the tank.

The reason I question the study is it was done along time ago and no one followed it up. The importance of CO production in rusting metal would impact any one who uses steel near salt water. Building an enclosed space that produces CO, for example a ships cabin, would be dangerous. CO is cumulative and low dose chronic exposure would at some point show itself.

If someone has a copy of the article in it's entirety , it might clarify how the CO is produced. As with many studies, initial findings are just that. There needs to be confirmation and repeat-ability.

Most ships cabins and holds are not pressurized to 2500 psi.

 

[vincent54]

True. I do think the study should be updated especially if they only used 6 tanks.

 

[Peter_C]

From Doc's other thread.
"The steel cylinder was pressurized with air (20.9% oxygen) the residual gas was analyzed after 100 days.

After 100 days at about 104 degrees F, the cylinders were removed from the bunker, the water was dumped and the cylinders were examined.

The most surprising finding, however, was the residual gas analysis. The gas in the steel cylinder had very abnormal values: oxygen was significantly reduced (15.0%), carbon monoxide was elevated (10 ppm) but carbon dioxide was normal (0.01%). The Law of Thermodynamics predicts that such a drop in oxygen content would be associated with the production of 1.5 pounds of rust, which agrees well with what was found inside of the cylinder."

So if the cylinder you tested was "NEWER" and had not been stored for 100 days in 104 degrees, how could the CO have exceeded their test results to the tune of 8 times more? If 10ppm of CO required 6% O2 to produce where did the rest of the O2 required come from? What was the O2 reading on the OP's tested tank? Most likely there must have been an outside source of CO, not generated from within the tank itself.

My partner is a chemical engineer. She did a few minutes of research and said it is possible but mentioned heat, and when I said like around 100 degrees, she said no far higher. The reality is the rust and the CO are probably coincidence and nothing more.

I am wide open to hear, read, and learn more about the subject. No where did I offer an absolute. So to point something out whether it is aimed at me or not, saying stuff like this below just makes you out to be an...

These recipes may come in handy for a couple of posters to this thread:
Three Crow Recipes

 

[grf88]

From Doc's other thread.
"The steel cylinder was pressurized with air (20.9% oxygen) the residual gas was analyzed after 100 days.

After 100 days at about 104 degrees F, the cylinders were removed from the bunker, the water was dumped and the cylinders were examined.

The most surprising finding, however, was the residual gas analysis. The gas in the steel cylinder had very abnormal values: oxygen was significantly reduced (15.0%), carbon monoxide was elevated (10 ppm) but carbon dioxide was normal (0.01%). The Law of Thermodynamics predicts that such a drop in oxygen content would be associated with the production of 1.5 pounds of rust, which agrees well with what was found inside of the cylinder."

So if the cylinder you tested was "NEWER" and had not been stored for 100 days in 104 degrees, how could the CO have exceeded their test results to the tune of 8 times more? If 10ppm of CO required 6% O2 to produce where did the rest of the O2 required come from? What was the O2 reading on the OP's tested tank? Most likely there must have been an outside source of CO, not generated from within the tank itself.



I am wide open to hear, read, and learn more about the subject. No where did I offer an absolute. So to point something out whether it is aimed at me or not, saying stuff like this below just makes you out to be an...

Peter, this was definitely not directed at you, in fact your post was very useful and I thank you. You will notice I said a couple of posters in the thread and if you read the thread you will quickly see who I mean. It was not so much as what was said but the "listen stupid, it came from the compressor" tone that was presented.

As for the cylinder in question it contained more salt water than the test cylinder, the time stored was unknown but the temperatures would have been quite high. The 6% of oxygen would mostly have been consumed producing the rust rather than the CO.