Sciencemadness Discussion Board

Dry Ice Source

anticoplanar - 29-3-2007 at 16:29

Anyone have a good source of dry ice? I thought it would be more straightforward.. but apparently not in my area.

prole - 29-3-2007 at 17:29

Yellow pages, 'Dry Ice'. Party supplies, some grocery store meat departments, ice cream stores. Don't know what part of the world you reside in, but in most developed countries have at least one of these in every town. Here in the sputtering Motor City, we even have a store that only sells dry ice. If you're desperate, call up one o' them stores that sells high priced steaks and ask for some high priced dry ice. I used to work grounds at a local fancyshmancy hospital and the people carting around body parts between clinics dropped chunks of dry ice in the parking lots all the time. Never found body parts though. But it's around, Bro'. I haven't checked in a while, but I Am A Fish (board member) has a great thread on OTC chems, and I think dry ice is on it. The thread's in this forum on the top of the page. Have a look.

guy - 29-3-2007 at 18:27

Albertson's

Sauron - 29-3-2007 at 23:44

Dry ice is usually sold in rectangular blocks. You have to break these up into smaller chunks, and fr freezing mixtures this is still not the optimum method.

What you really want if you can afford it is a cylinder of liquid CO2 with a dip tube. You don't need a pressure regulator just a valve. There's a commercially available and reather inexpensive ($150) device that attaches to the outlet, and provides a plastic cone and bags to store dry ice in snowflake form, this is ideal for freezing mixtures, cold caths, Dewar condensers etc. Aldrich sells these.

The same manufacturer sells much more expensive machines that attach to same liquid CO2 cyl. and produce 1 lb. cylindrical blocks of solid dry ice but, for most lab purposes these have no advantage over buying dry ice in larger rectangular blocks.

A nasty accident occured when using the snowflake dry ice maker. The instructions said to open the valve 3/4 turn, that is three quarters of a turn. The operator read that as three or four turns, he inundated himself with liquid and solid CO2 and suffered bad cryo burns. Evolution in Action I suppose.

garage chemist - 29-3-2007 at 23:58

I have once procured a 10kg CO2 bottle with dip tube in order to be able to make dry ice on the spot when needed. I used a "snow pipe" (Schneerohr in german), which could be borrowed from the gas supplier along with the CO2 bottle for a minimal fee (5€). This makes fluffy CO2 snow, which can be pressed if necessary.
I will never do this again- from 10kg CO2 in the bottle, I got maybe 300g dry ice.
The process of letting liquid CO2 of room temperature expand to atmospheric pressure in order to make solid CO2 is incredibly wasteful of CO2 when the CO2 that vaporizes is not recycled.
The CO2 bottle was empty after just one use for cooling something. You will notice the same with those dry ice pellet makers. They are useless except when you have absolutely no other source of dry ice and lots of money to spend on CO2 bottle refills.

Liquid nitrogen is way cheaper than this selfmade dry ice. It would still be cheaper to solidify CO2 by cooling the gas from a bottle with LN2 and pressing the so obtained snow than to use a CO2 bottle with dip tube, if dry ice has to be used, e.g. when LN2 is too cold (like when working with liquid anhydrous NH3).

not_important - 29-3-2007 at 23:59

You may be able to find dry ice in both block and pellet form, the pellets usually being about a cm across and several cm long. The pellets work well for log temperature baths, they're the best alternative to getting a cylinder of CO2 which may be difficult especially if you're young or lack a way to transport it (do not attempt to take it on the bus)

Sauron - 30-3-2007 at 01:13

hanks for the tips, @gc as I was about to buy a bottle of liquid CO2 and one of the commercial CO2 snow makers. The local agent for the manufacturer is an asshole, the thing is like $125 in USA and he quoted $350 to me here. So I was going to buy it from Cole Parmer's agent here.

Now I will just buy blocks of dry ice and bust them up as needed, the local supplier will deliver to my door, and it is sold by the Kg cheap.

chemrox - 2-4-2007 at 20:39

Quote:
[There's a commercially available and reather inexpensive ($150) device that attaches to the outlet, and provides a plastic cone and bags to store dry ice in snowflake form, this is ideal for freezing mixtures, cold caths, Dewar condensers etc. Aldrich sells these.


Edmund Scientific has them for $100

http://scientificsonline.com/product.asp?pn=3071533&cmss...

I have no idea how efficient these are. In my area, ice cream parlors and manufacturers both carry dry ice in blocks for sale. I'm concerned that the makers like the one at Edmunds might be wasteful as in the experience reported by garage chemist.

[Edited on 2-4-2007 by chemrox]

[Edited on 2-4-2007 by chemrox]

Sauron - 3-4-2007 at 19:48

The Edmund ad claims 25% conversion efficiency which would be 2.5 Kg from a 10 Kg (net) cylinder.

@gc however reports only 300 g from such a cylinder which is a miserable 3%.

Anyone else have any hands-on experience with this?

Edmund is certainly a more amateur-friendly vendor than some of the distributors for the OEM, who immediately start playing 20 questions as if you were ordering something suspicious. It's a frigging pipe, a plastic cone, a plastic bag and a hose clamp for crying out loud! You would think they'd want to kiss anyone willing to give up $100 for this, but nooooooo.

quicksilver - 7-4-2007 at 07:10

Quote:
Originally posted by Sauron
Edmund is certainly a more amateur-friendly vendor than some of the distributors for the OEM, who immediately start playing 20 questions as if you were ordering something suspicious. It's a frigging pipe, a plastic cone, a plastic bag and a hose clamp for crying out loud! You would think they'd want to kiss anyone willing to give up $100 for this, but nooooooo.


That whole issue hits a nerve with me. From a personal perspective I would shove it right back in the guy's face.
I only had a fellow play 20 questions with me once. I had an account at a very large chem supplier and did the ordering for work at the same supplier. - They knew me and I order by PO & credit card, etc. The inference was that the glassware was meth-cook stuff of course. I was stunned that with a track record of using a CC and buying common items someone would even contemplate playing policeman.
- I made a case for shopping around for a better supplier to the owner and he agreed. I called back and made damn sure I got a supervisor on the line and told him our account with them was finished. I explained that any inference that the use of glassware for illegal purposes was considered insulting and "investigations" should not be carried out by an order clerk. They insisted that was never their policy, etc. & that it would never happen again. But if people don't speak out on this type of abusive interrogation then IMO we get victimized over and over.

Sauron - 7-4-2007 at 12:59

You acted very propely. No one ordering with proper credentials (business/institutional account with an EIDN, CC etc.) should be harassed. That's absurd.

I recently terminated my relatioship with local agent for Cole Parmer because they and/or Cole Parmer stuffed me around over an order for a $500 pair of nitrile glovebox gloves. After 90 days they fessed up the Cole Parmer wanted an export license from the US Govt, due to war on terror. Bullshit. Nitrile gloves are not a regulated item. I imported the complete Labconco glovebox, with gloves, from USA with proper declaration, and had no difficulty with US Customs outbound. But here's a supplier jerking me around for a frigging pair of gloves! I'm a US citizen and live in a country that's a major Non-NATO US ally. for Christ's sake. What crap! And I told them so.

The world is full of officious little shit clerks. They seem to proliferate like rabbits, or like coathangers in closets.

I used to be a registered licensed manufacturer/exporter of defense articles that ARE controlled by the US State Dept Office of Munitions Control so I am very familiar with their regs.

Nitrile gloves? Nope.

polymer - 8-4-2007 at 06:53

Grocery stores typically carry dry ice