Dewar Ditty

Dewar ditty, I’m a wondering what to do.
Dewar ditty, liquid N or CO2?

Dewar ditty, got to chill some ethanol
Dewar ditty, without going in the hole.

Dewar ditty, I’m still wondering want do
Dewar ditty, so I’ll ask the Good Life crew…

There are a number of threads discussing how to get your solvent cold.

Either on a budget, or in a hurry, or with huge chillers that aren’t a huge disappointment.

I needed to get that ditty out of my head, and I’m gonna try direct liq CO2 injection.

I figured I’d try and document where the required clues can be found lying around, while I go find them again.

Under the assumption that that would be useful for others later.

Getting two birds stoned is almost always a win :wink:


A client suggested these as a solution, C1D1 Labs | Low Temp and Cryogenic Lab Freezers

I responded with “how about we get a CO2 Dewar, and see what we can manage…”.

Chances are he’ll do both.


so…I did use a dewar (two) of LiqN2 for chilling ethanol.

with just a dewar and a phase separator on a six ft hose, I wasn’t really able to give LiqN2 a fair trial. It certainly worked, and the head pressure was great for moving my solvent around, but we went with dry ice while waiting on actual chilling.

if you’re looking for a Chiller Recommendation

I don’t currently have one.

@ThermonicsChillers recommends you take a look here

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Hi cyclopath - thanks for linking to us.

Just a couple of thoughts:
If you are going cryo, LN2 will offer better/lower cooling than LCO2.
I realize many people say, “I only need -40” but if you want rapid cooling of a large volume to -40, you need a system with much lower capabilities (i.e. -80); it’s all about DeltaT in the heat transfer.

With the LN2 chiller options, we know they are SIGNIFICANTLY less expansive than more traditional, compressor based chillers. The rub is always in LN2 consumption and once your processing volumes grow, you won’t be able to rely on Dewars anymore, you’ll need some sort of Bulk LN2 Supply. This can be achieved in a couple of different ways: a flatbed truck with a larger tank parked outside your facility or a complete building retrofit to install massive tanks.
And we’ve found that LN2 pricing is all over the place depending on vendors/location. We know you can get it bulk for less than 20 cents a liter but some of our customers have reported gauging of $1.00 plus per liter. Point being, make sure you have something in place tha locks yo into an agreeable price for LN2.

I’m not biased towarfs LN2 chillers, Thermonics sells mechanical chillers as well. But we know that the LN2 options are a much lower capital equipment cost and the cost of the expendable LN2 is only incurreed once you are producing product that’s bringing in revenut/profit, so it’s an easier expense to absorb.

Good Luck!

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