CROCK POT CO2

[BlindDate]

Now normally my research is not so sloppy, but this time I’m just too damn busy to do it right. Therefore I’m going to leave it up to the brilliant folks at IC to carry the torch. If you guys think that this is a good idea, go forth and bring your results back for all to share.

Basic Principle:

Sodium Bicarbonate (Baking Soda) + HEAT = Sodium Carbonate, H2O & CO2 Gas

When SB is heated to a temperature above 50 degrees C it starts to give up CO2 gas. The process accelerates at 100 Deg C and finishes at 200 Deg C.

I have been running this Crock Pot for several days now with 10 lbs of SB inside at 100 deg C. I have the output tube in shallow water so that I can see the bubbles and know it is still producing CO2 gas.

 

[`tonic]

Don't hurt yourself..

 

[BlindDate]

It is important to get a model that has a good airtight seal if you want to keep the Crock out of the grow room. This Hamilton Beach model is the only one I could find with a locking seal. The lid had a few rivet holes. One I sealed with silicone and the other I used for the output tube.

Of course if you don’t mind the extra heat inside your grow then anything will work. Hell, stick a toaster oven inside the room. I’m sure that some of you could see it in your setups to come up with all kinds of methods.

 

[BlindDate]

At 100 deg C it bubbles at a constant rate, but I did hook up a flow meter and measured about .3 -.5 CFH.

If I were to kick up the temperature higher I’m sure that I would get more flow, but that’s the highest a Crock Pot will go.

It is important to get a unit with a manual control rather than digital. That way you can put it on a timer for when the lights go out.

 

[BlindDate]

For you guys with some chemistry background I have a few questions:

1. How much CO2 gas will 10 lbs of SB produce and at what temperature?
2. Does anyone have a temp/CO2 output curve chart?

One last thing:

I was thinking that if I were to mix the SB with a vegetable oil or peanut oil to make a slurry, I might get a more uniform flow since the oil would distribute the heat more evenly.

 

[bostrom155]

tag

 

[CarpeNoctem]

Sorry dude Its been to long since i took chemistry, wish i could help. The oil sounds like a good idea though. Good luck will love to see the results from this.

/bump it up!

 

[Latitude18]

great thread

great thread

I was looking into the yeast method , but I only have a lil box , your method sounds good , I'd be iterested in any formulas that could be used also.

for a micro grow , I was think'n a coffee cup warmer or a coffee pot burner may work well with a Pyrex pie pan , or such ... with your method and a formula anyone could have co2 cheep and easy

I have time and plan to go look into it now , but I don't have a co2 meter to test any findings , so... I'll post anything worth while , when and if it's found.

Thanks BD

 

[BlindDate]

Try it out Latitude18. Don't worry about the meter, just place the output tube in some shallow water. A good steady bubble from an aquarium tube is about 0.5 Cubic Feet/Hour. Try using the peanut oil (peanut oil has a very high vapor temp).

I tried the yeast method in the past. It's a damn shame that all was lost on Overgrow. There were MANY methods using yeast.

Yeast is less predictable, and, you cannot just shut it off at lights out.


The Crock Pot works OK, but I wish I could regulate the temp.

 

[MTF-Sandman]

Hey BD, looks like a decent CO2 generator...do you happen to know what the energy consumption of the crock pot is and how much it messes with your temps? Seems like it might be costlier in the long run due to energy usage and refilling the pot with baking soda...

 

[bartender187]

imo good ventilation is all you need, unless you want to plop downt he investment for a tank+regulator setup.

neat idea tho

 

[BlindDate]

Hey BD, looks like a decent CO2 generator...do you happen to know what the energy consumption of the crock pot is and how much it messes with your temps? Seems like it might be costlier in the long run due to energy usage and refilling the pot with baking soda...

Energy use is 265 watts. I keep the Crock outside the grow so heat is not a factor for me. Baking Soda is very cheap at Costco 12lbs for $3.50.

 

[MTF-Sandman]

Sweet...I figured it'd use alot more juice than that. I just might have to try this. Nice little invention ya got there

 

[gsxxer]

so you feed that tube into the top of the grow box? or do you have a grow box?

how much distance can you between the crockpot and the box?? Im just confused on exaclty where your putting the other end of the outake

 

[BlindDate]

I am putting the output in a 7 x 7 closet. Distance is about 4-5 ft. No need to put it at the top. I have it in front of a fan.
The Crock sits outside the closet with my ballast.

 

[Latitude18]

here's what I found

here's what I found

I did a lot of search'n and read'n. Basicly I found nothing on heating up Baking soda to make CO2. Everytime I added heat to the search , it threw up on me , with a ton of baking recipes. Have a few feelers out to smart people, so I hope to hear something. I still have to add a few things to the search to really get info.

Basicly, what the Q is , is : How much Baking soda + how much heat = how much CO2 for how long, and is it a steady release.

still looking , and have plans for my own lil CO2 genny , or two. I want to turn your idea into a micro version ( My $10 coffeepot holds my coffee at 150*F , kinda right on the mark ) , if the heating doesn't screw the pooch( heat , micro , and stealth don't mix to well) , and also do a few experiments. you can desolve the B/S in water and add salt , heat it and see if that does more then dry. which is accually two experiments , one to see if desolve'n it works and the next to add the salt ( I have my reasons , got Ideas from reading all yesterday ). Table salt adds surface area for the CO2 to attach to , or some such stuff.

anyway, I'll stop Blabbering , and get to work. The more I think about it , the more experiments I come up with.

 

[BlindDate]

Baking Soda is FULLY disolved in water at a ratio of 10 to 1. That means 10X as much water by volume as Baking Soda (impracticle). By adding at least some water you can create a slurry (wet but undissolved Baking Soda).

The reason that I sugested Peanut Oil is because it has an extreamly high boiling temp. With water, you will boil if off at the same temp it takes to release the CO2 from the Baking Soda.

Again, I only recomended trying it so as to heat the Baking Soda evenly.

I also could not find any answers regarding the amount of gas produced by method of heating, but I do know that when baking soda is reacted with an acid, 1 lb of Baking Soda will produce 4.3 cubic feet of gas.

 

[bartender187]

^^
CO2 Sinks--- but if you have your vent fan on, most of the CO2 is getting sucked straight out the room.

 

[BlindDate]

Bartender says:

CO2 Sinks--- but if you have your vent fan on, most of the CO2 is getting sucked straight out the room.

1. CO2 does not "sink". That is an urban myth propagated by newby morons on these boards. There is a thing called "dispersion of gases". That is why you do not come home after your vacation to find that the Oxygen, Nitrogen and Carbon Dioxide have separated into layers inside your house. That is why you can smell a fart from the other side of the room.

2. Why in the hell would anyone vent the room when they are using CO2?

 

[bartender187]

^^
Yup, this sums it up quite well...

The molecular weight is very important for it means that this gas is much heavier than air (50% heavier or 1 and 1/2 time as heavy). It will mix with the air as all gasses do (because of Brownian motion . . . the molecules bumping into each other). But, because it is much heavier than air, (and much heavier than carbon monoxide), it will take longer to mix and, thus, disperse

And btw, no need for name calling, I just highly doubt this is worth the trouble.

To adress your second point- they dont, but whats your plan? This at BEST is at co2 drip system, no way it can create the amount of CO2 needed to raise to optimal levels in the short time your vent fan isnt on. This might be more plausible if you grew in a sealed room using A/C or something other than a vent fan to regulate temps.