Best way to generate CO

July 13, 2013 1:29 PM

For an experiment on the effects of CO on various plants, I will need enough CO to fill a room about the size of a closet. It seems cheaper and easier to generate CO via a hibachi grill inefficiently burning charcoal than to purchase it in pure form. I was wondering if there is an even better way than using a hibachi. Obviously I am well aware of the risks of Carbon Monoxide poisoning and will be taking the full necessary precautions to avoid asphyxiation.
posted by MattMangels to Science & Nature (13 answers total)

You should just be able to buy a tank of it from Airgas or a similar supplier. Is that not feasible?

If this is for school, check with the dispensary in the chemistry department.
posted by backseatpilot at 1:39 PM on July 13, 2013 [1 favorite]

Obviously I am well aware of the risks of Carbon Monoxide poisoning and will be taking the full necessary precautions to avoid asphyxiation.

Off the top of my head:

Are you taking the full and necessary precautions to protect others nearby? Are you taking full and necessary precautions to protect yourself against civil or criminal charges? Are you compliant with OSHA? Have you conducted a risk assessment? Written a standard operating procedure? What happens if something goes wrong with your CO source?

CO is not to be screwed with: 50ppm is an occupational limit according to OSHA, and it is remarkably toxic pure, and a really insidious way to poison yourself and others.

Burning stuff inefficiently does not make pure CO; thus you would not be "filling" a closet with it, and you will be releasing all kinds of other materials into the space where your incomplete combustion goes.

This sounds, at best, like a poorly constructed and thought out experiment.
posted by lalochezia at 1:51 PM on July 13, 2013 [28 favorites]

CO from a hibachi, a car engine, etc., is going to be laden with contaminants that will confound your results; and in any case you'll need to get your CO from a controlled source in order to be able to say with some accuracy what CO concentration your plants were finally exposed to.

Seconding lalochezia that if this is for school, you probably want to spend some time talking to your instructor about the design of your experiment.
posted by Bardolph at 1:55 PM on July 13, 2013 [3 favorites]

If this is for school, ask your teacher to help you contact a local postsecondary institution that would have plant growth chambers. Summer may be slower and they may have the space to allow you to use one pro bono.

Plant growth chambers will have airtight door seals and septa for gas lines so that you could safely conduct this experiment.

Please do not do this at home. CO is odorless, colorless, tasteless, and will distribute itself fairly evenly in air.
posted by variella at 2:01 PM on July 13, 2013 [6 favorites]

Filling a closet sized enclosed space with the toxic products of inefficient charcoal combustion isn't "taking the full necessary precautions to avoid asphyxiation". It just isn't.

This kind of experiment would be explicitly not allowed at any of the Universities I've worked at (and I have worked with dangerous gases on occasion) and honestly, I wouldn't be surprised if it's illegal in at least some places. It's really dangerous and kind of stupid.

It also makes no sense scientifically. You'll be making CO rather slowly, you won't know how much you're making or where it's going exactly (it's slightly heavier than air so won't be filling your chamber evenly), you'll also be making a bunch of other products which are toxic to the plants (e.g. smoke) also in unknown rates and overall quantities, and you'll be adding a heat source on top of everything else. You won't find out the answers to your questions using this set up.

I agree with variella, if you want to do this properly there is equipment specifically designed for these kinds of experiments. You need to get hold of some, be properly trained in how to use it (including how to use the gas), and get this whole thing signed off by someone who knows that they are doing.
posted by shelleycat at 2:27 PM on July 13, 2013 [6 favorites]

If you attempt to present me, or any other evidence-based person, with any conclusions based off your co-incubation of a plant with a hibachi in your closet experiment, you'll be laughed out of the room.
Just from a scientific methods standpoint, you have no way of controlling the amount of CO2 produced by a charcoal grill. Therefore you cannot know A. how much CO2 you're actually exposing the plant to and B. for how long. That makes it impossible to replicate your experiment, and even reproduce your results.
That is a purely academic reason of why you shouldn't even think about doing this.
posted by Cold Lurkey at 2:29 PM on July 13, 2013 [2 favorites]

If I were you, I would contact your local University with an agriculture program, and set up a phonecall to talk about possible experiments with a professor or bright grad student. They will have interesting things to say.
posted by tintexas at 2:43 PM on July 13, 2013 [2 favorites]

Why don't you drop the dangerous CO idea, and see what happens if you use CO2 instead? You can use dry ice for that, but be sure to wear gloves or use tongs while handling it. You could easily put that in the grill, and you wouldn't die either. Worth considering.
posted by oceanjesse at 2:51 PM on July 13, 2013 [1 favorite]

Filling a closet sized space with CO2 is also dangerous. I've had to have specific training when using large-ish amounts of dry ice in enclosed spaces and that was much less than it would take for this. Even fairly small amounts of dry ice or CO2 gas can kill you when handled incorrectly.
posted by shelleycat at 2:59 PM on July 13, 2013 [7 favorites]

You can purchase lab-quality CO. You will probably need a license to do so.

You do not sound like you have any sort of lab safety or dangerous materials training. Trying to fill a space with CO seems foolhardy at best, or perhaps criminally negligent. Why not find someone competent to perform the test for you?
posted by KokuRyu at 6:04 PM on July 13, 2013 [2 favorites]

If you really want to use CO I would wander over to your university chemistry department (you are in university right? otherwise you shouldn't be playing with CO it is actually very dangerous as in as dangerous as cyanide dangerous not to be trifles with) and ask them how you should set up the experiment. See if someone has a spare glove back lying around and will allow you to use a lab hood and bring in some of your lights (you're using controlled lighting for this experiment right?) and grow the things in the hood. That way if there is any leak it just gets whisked out of the room and mixed with the air to dilute it below normal levels. They would also have a source of CO for you to use because you really won't need much.

Are you going to try and grow things in pure CO or in a mix of gasses. If it is a mix it will be rather difficult to get the ratio just right, not impossible just difficult and you'll either need to use quite a few large gas syringes or if you're ok with the error use some water displacement to measure the volume of gasses going into your experiment.
posted by koolkat at 3:50 AM on July 14, 2013

Using a Hibatchi indoors? Continuously? Your biggest risk is from fire.
posted by Ironmouth at 6:46 AM on July 14, 2013

MattMangels: "It seems cheaper and easier to generate CO via a hibachi grill inefficiently burning charcoal than to purchase it in pure form."

That's not true once you include purifying and measuring your CO output. Is this for a high school science project? Don't screw around with carbon monoxide if you're doing a high school science project.
posted by d. z. wang at 9:22 AM on July 14, 2013