When carbon based fuel is burned completely in an oxygen rich environment, it produces carbon DIoxide (CO2) and very little carbon monoxide (CO). When fuel is burned incompletely, it starts to produce significant amounts of carbon monoxide.
Carbon monoxide is a toxin. It binds to hemoglobin, your body requires considerable time to clear it, and even quite low levels can be dangerous. Every winter people die from malfunctioning heaters that incompletely burn their fuel. This occurs in houses, which generally are much less air tight and have much more reserve volume than boats.
Gas engines incompletely burn their fuel, and produce significant amounts of carbon monoxide. Turn on the Honda Accord, close the garage doors, and you have efficiently committed suicide. Diesel engines, functioning correctly, more completely burn their fuel. One fellow tried to commit suicide a year or so ago by locking himself in his garage and turning on his diesel Volkswagon Rabbit. After several hours, it ran out of fuel and he was still alive. (Do not interpret this as a preference for either car.)
Don't confuse carbon monoxide with smoke, or think that the odor or color of a fire or an engine's exhaust tells you how much carbon monoxide it produces. Carbon monoxide -- like carbon dioxide -- is clear and odorless. You can be in a comfortable room thinking you are breathing clean, pure air until your cheeks turn red and you fall over dead.
Carbon monoxide poisoning confuses people. This is part of its deadliness. When you are comfortable and confused, you are less likely to realize that there is a problem.
Alcohol, kerosene, and propane generally burn completely and cleanly in a well-functioning stove, producing a good amount of carbon dioxide but little or no carbon monoxide. Does this mean that you can safely ignore exhaust leaks in your diesel inboard and not worry about carbon monoxide from your stove?
Absolutely NOT. There are two problems. (1) Even small amounts of carbon monoxide can be dangerous if you are in a tight, small container for prolonged time periods, e.g., a completely closed up boat overnight. (2) Almost everything that burns carbon fuel completely will burn it incompletely in certain conditions. And you cannot tell from direct observation.
Do not let your exhaust leak. If you are going to burn stoves for long periods of time, ventilate well or get a carbon monoxide detector. Be safe.
Burners and carbon monoxide (CO)
Moderator: Jim Walsh
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D. Stump, Hanalei
Re: A very straightforward discussion!! Thank You!
Russell,
Thank you for a very straight forward discussion about the CO hazard. I think it is a good thing when we all stop and think about hazards that we are not normally exposed to. I doubt very much if I would ever sleep with the alcohol stove burning all night long, with or with out the clay pot. The fire hazard alone would be enough to preclude that! I would use it only to take the chill off when at the slip or anchorage. Of course, when I used it last weekend, the dorrade vent forward and the cowl vents aft were open, as well as the companionway hatch slightly ajar with one companionway board removed. So the atmosphere had plenty of ventilation. Also, the alcohol flame itself was burning blue, no yellow, and the burner had plenty of supply air. I doubt very much if it created any CO, understanding that the only way to really tell is to use a CO detector.
Thanks again for you insight....
Dave Stump
Captain Commanding
s/v Hanalei
Thank you for a very straight forward discussion about the CO hazard. I think it is a good thing when we all stop and think about hazards that we are not normally exposed to. I doubt very much if I would ever sleep with the alcohol stove burning all night long, with or with out the clay pot. The fire hazard alone would be enough to preclude that! I would use it only to take the chill off when at the slip or anchorage. Of course, when I used it last weekend, the dorrade vent forward and the cowl vents aft were open, as well as the companionway hatch slightly ajar with one companionway board removed. So the atmosphere had plenty of ventilation. Also, the alcohol flame itself was burning blue, no yellow, and the burner had plenty of supply air. I doubt very much if it created any CO, understanding that the only way to really tell is to use a CO detector.
Thanks again for you insight....
Dave Stump
Captain Commanding
s/v Hanalei
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Don S.
Re: A very straightforward discussion!! Thank You!
If I'm not mistaken (and I might be) The products of an achohol burn are water and carbon dioxide, not carbon monoxide. Of course yer just as dead but the poison's not accumulative.
don@cliggott.com
D. Stump, Hanalei wrote: Russell,
Thank you for a very straight forward discussion about the CO hazard. I think it is a good thing when we all stop and think about hazards that we are not normally exposed to. I doubt very much if I would ever sleep with the alcohol stove burning all night long, with or with out the clay pot. The fire hazard alone would be enough to preclude that! I would use it only to take the chill off when at the slip or anchorage. Of course, when I used it last weekend, the dorrade vent forward and the cowl vents aft were open, as well as the companionway hatch slightly ajar with one companionway board removed. So the atmosphere had plenty of ventilation. Also, the alcohol flame itself was burning blue, no yellow, and the burner had plenty of supply air. I doubt very much if it created any CO, understanding that the only way to really tell is to use a CO detector.
Thanks again for you insight....
Dave Stump
Captain Commanding
s/v Hanalei
don@cliggott.com
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Russell
Carbon dioxide is fairly innocuous ..
As long as the alcohol is burning completely, you are right that its byproducts are CO2 and water. The air you breathe contains -- if I remember correctly -- just under one percent of CO2.
Where does all this CO2 come from? From all the natural burners of carbon fuels: animals, including people. Now, of course, the artificial burners of carbon fuel -- motors, stoves, and factories -- have increased the level of CO2 in the atmosphere.
Back to people. You take in oxygen, combine it with the carbohydrates that you consume, and exhale CO2, generating the energy that invigorates you. Your lungs will contain a relatively high percentage of CO2 just before you exhale. It is the buildup of CO2 in your lungs, rather than the depletion of oxygen, that triggers the respiration cycle.
At some level (I don't know what), a rise in CO2 in the air you breathe will produce acidosis, which is why submarines require chemical scrubbers to purge air of the CO2 that the crew members produce. I doubt that an alcohol stove is much more a danger from its CO2 production than you are to yourself. Which is to say, not very much, unless you are on a submarine. You burn enough carbon to generate approximately 2,500 Kilocalories of energy every day. More when you are on a boat. That's enough carbon oxidation to take 25 liters (6 gallons!) of water from just about freezing to a boil. Quite a bit! Unless you are cooking for the entire submarine's crew, you don't use your stove that much.
BUT ..
If the alcohol stove is NOT burning cleanly for some odd reason (bad air flow, contaminated fuel, etc.), it may produce a tiny little bit of carbon monoxide. And carbon monoxide will kill you at doses much, much, much smaller than the level of carbon dioxide in the ambient atmosphere.
The story is complex. But for most purposes (other than designing a submarine and concerns about global warming) you can view carbon dioxide as a ubiquitous and inconsequential byproduct of carbon fueled engines -- natural and artifical. In contrast, carbon monoxide is a sneaky and deadly poison.
Russell
Where does all this CO2 come from? From all the natural burners of carbon fuels: animals, including people. Now, of course, the artificial burners of carbon fuel -- motors, stoves, and factories -- have increased the level of CO2 in the atmosphere.
Back to people. You take in oxygen, combine it with the carbohydrates that you consume, and exhale CO2, generating the energy that invigorates you. Your lungs will contain a relatively high percentage of CO2 just before you exhale. It is the buildup of CO2 in your lungs, rather than the depletion of oxygen, that triggers the respiration cycle.
At some level (I don't know what), a rise in CO2 in the air you breathe will produce acidosis, which is why submarines require chemical scrubbers to purge air of the CO2 that the crew members produce. I doubt that an alcohol stove is much more a danger from its CO2 production than you are to yourself. Which is to say, not very much, unless you are on a submarine. You burn enough carbon to generate approximately 2,500 Kilocalories of energy every day. More when you are on a boat. That's enough carbon oxidation to take 25 liters (6 gallons!) of water from just about freezing to a boil. Quite a bit! Unless you are cooking for the entire submarine's crew, you don't use your stove that much.
BUT ..
If the alcohol stove is NOT burning cleanly for some odd reason (bad air flow, contaminated fuel, etc.), it may produce a tiny little bit of carbon monoxide. And carbon monoxide will kill you at doses much, much, much smaller than the level of carbon dioxide in the ambient atmosphere.
The story is complex. But for most purposes (other than designing a submarine and concerns about global warming) you can view carbon dioxide as a ubiquitous and inconsequential byproduct of carbon fueled engines -- natural and artifical. In contrast, carbon monoxide is a sneaky and deadly poison.
Russell
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Ryan Turner
Excellent description -- I love the way you write!
I wanted to make this comment without a message but this BB won't allow that. Anyway, I just wanted to compliment Russell on his excellent and descriptive writing.
Ryan Turner
rdtec@aol.com
Ryan Turner
rdtec@aol.com
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paul O
Re: Excellent description -- I love the way you write!
the concentration of CO2 in the atmosphere at sea level is about 330 parts per milion by volume. This number was lower before the industrial revolution (less than 300), and it continues to increase.