Sciencemadness Discussion Board - How to Safely release DiEthyl Ether vapors in air?

How to Safely release DiEthyl Ether vapors in air?

enertech - 13-3-2014 at 21:38

Hello friends!

I have just installed a mixing vessel in which I use Diethyl Ether for mixing and washing an organic powder material. After washing/mixing for a few minutes I don't need to filter it and just want to evaporate the ether. The quantity of Ether in one batch is around 25 to 30 liters.

When I start the mixer with slow rpm, the ether gets vaporize itself and I have installed an exhaust pipe from the top of mixer for travelling ether vapors.

The problem is, still I am afraid of going those vapors directly in air and causing any fire/explosion nearby.....

So, can any one please suggest me a suitable solution to scrub or decompose these ether vapors so that it could not create any harm when released in air?

It's very serious problem for me, please try to help me out......

[Edited on 14-3-2014 by enertech]

thesmug - 13-3-2014 at 22:08

30 liters

. I know this isn't exactly what you wanted but do you have any means of capturing these vapors?

enertech - 13-3-2014 at 22:30

My product economics allow me to evaporate the ether instead of collecting/condensing its vapors for re-use.

So, in simple words, I don't need the recycled ether at the end of my mixing process and just want to release its vapors in air safely.

Mailinmypocket - 14-3-2014 at 03:23

This is true. What exactly does sloshing around the product (and impurities) around in ether and evaporating do exactly? The impurities will just dry out along with your product so you're back to square one. Typically you would wash ether over the product in a funnel allowing the impurities to run through. Also, if your product economics allow you to waste that much ether surely your product economics could allow for a pretty sweet distillation set up to recycle the ether!

[Edited on 14-3-2014 by Mailinmypocket]

woelen - 14-3-2014 at 03:30

This sounds very much like a process on a (semi)industrial scale and is not in the realm of hobby chemistry.

Please specify more about your process.
- What do you want to reach with the rinsing/dissolving in ether?
- What kind of compound are you processing (cleaning? purifying?)

If you are more specific then you have a better chance of getting help. Nobody wants to help some large scale drugmaking lab and if you are clear about your process and take away any doubts, then surely people will be more helpful.

enertech - 14-3-2014 at 06:54

Thank you for your comments friends. I am trying to elaborate about my posting.

Actually I am doing research on pilot scale for creating a coating/film on some Inorganic Powdered oxides and Pigments (like TiO2, ZnO, Inorganic pigments like Phthalocyanine Blue/Green). The film forming material is soluble in Ether and the Powder compound is insoluble. So, I first dissolve the coating material in Ether and then just "dip" the powder fully in Ether creating a homogeneous slurry, mix it slowly to thoroughly coat the powder particles with coating agent, and then finally evaporate the ether.

The reason to choose Ether here is due to its very low BP which helps me by not leaving significant solvent residues in final coated powder after evaporating and it surprisingly also gives good coating results.

I tried this in very small batch size (in ml and grams) in lab but now reproducing the batch on pilot scale, I am being afraid for the safety measures.

By mistake I used the word "washing" of Ether in my first post, as actually it's just "dipping". Sorry for that!

So friends, now may I get any help for this task?

[Edited on 14-3-2014 by enertech]

Mailinmypocket - 14-3-2014 at 07:08

I still don't understand why you wouldn't want to just invest in a distillation set up? Given the nature of what you are doing reusing the ether seems like a much safer and economical (despite you saying the cost is not a problem)way to go about your process.

Evaporate it off outside, using low heat. What else can we say?

enertech - 14-3-2014 at 07:20

Yes, evaporate it using low heat. But again, my question is:
What about those fugitive vapors going out quantitatively in the atmosphere? Isn't there any solution to scrub, decompose or make less prone to burn/explosion those vapors?

What should be the safety measures at this stage?

Mailinmypocket - 14-3-2014 at 07:32

hmm..

There is no economical way to scrub ether vapors in that quantity. Perhaps by bubbling the vapor from a tube under water and doing some sort of controlled burn as the bubbles of ether vapor reach the surface of the water. Likely the water would condense the ether anyways so Im not even sure how well this would work, if at all.

If you are this serious into producing large quantities of your target substance you really should invest in a distillation set up. It doesnt have to be large capacity, you can always do smaller batches of evaporations. But that is how most chemists would go about it.

This is a rather roundabout way of solving a common laboratory issue .... removing solvents from solids. If you can invest in all that wastage of ether you can surely invest in a distillation apparatus. Then, if you still want to dispose of the distilled ether you could save it for other purposes, light bonfires with it... etc

woelen - 14-3-2014 at 09:59

Maybe you could absorb the ether in a fairly concentrated solution of an acid (e.g. 25% hydrochloric acid). Ether does not dissolve in water very well, but it dissolves very well in aqueous acids, forming an oxonium compound, with the H(+) bonded to a lone electron pair on the oxygen of the ether.

So, I can imagine that if you disperse fine bubbles of gaseous ether through a vessel with 25% HCl then most of the ether is observed. You could try this on a small scale with an aquarium bubbler through which you blow luke warm (e.g. 45 C) ether vapor into moderately concentrated hydrochloric acid.

thesmug - 14-3-2014 at 14:23

Quote: Originally posted by woelen

Maybe you could absorb the ether in a fairly concentrated solution of an acid (e.g. 25% hydrochloric acid). Ether does not dissolve in water very well, but it dissolves very well in aqueous acids, forming an oxonium compound, with the H(+) bonded to a lone electron pair on the oxygen of the ether.

So, I can imagine that if you disperse fine bubbles of gaseous ether through a vessel with 25% HCl then most of the ether is observed. You could try this on a small scale with an aquarium bubbler through which you blow luke warm (e.g. 45 C) ether vapor into moderately concentrated hydrochloric acid.

You could also try it with a higher concentration of HCl. If kept at fairly low temperatures (say by an ice bath or dry ice bath), you can bubble the ether through the HCl to chlorinate it, rendering it almost non-flammable (though a bit more toxic, so be careful). You can read more about it here: http://pubs.acs.org/doi/abs/10.1021/ie50605a021

HgDinis25 - 14-3-2014 at 16:22

You could lead the vapors through a narrow ended pipe and set it on fire. The flame would destroy the ether and you could use the energy generated to heat the vessel with your products. It's important to note that, in spite of burning the ether, there will still be a terrible smell where you burn it.

HeYBrO - 14-3-2014 at 17:00

Quote: Originally posted by HgDinis25

You could lead the vapors through a narrow ended pipe and set it on fire. The flame would destroy the ether and you could use the energy generated to heat the vessel with your products. It's important to note that, in spite of burning the ether, there will still be a terrible smell where you burn it.

Please do NOT do that OP. This will most definitely cause an explosion. Sorry, but this is just not a good idea.

HgDinis25 - 14-3-2014 at 17:06

Quote: Originally posted by HeYBrO

Quote: Originally posted by HgDinis25

Please do NOT do that OP. This will most definitely cause an explosion. Sorry, but this is just not a good idea.

If you keep a high pressure out, there shouldn't be a prouble. However, and because this is only an assumption not a fact, one could use a one way valve before the flame, setted to a certain outlet pressure. IF the pressure of ether going out decreases, the valve would close, not allowing a back explosion.
PS: I still think that a simple distillation (like other members recomended, would solve your problem)

thesmug - 14-3-2014 at 17:38

Quote: Originally posted by HgDinis25

Quote: Originally posted by HeYBrO

Quote: Originally posted by HgDinis25

Please do NOT do that OP. This will most definitely cause an explosion. Sorry, but this is just not a good idea.

There is no 100% way of making sure that the ether is only coming out through the valve. Leaks in glassware or machinery could be dangerous with an open flame nearby.

enertech - 15-3-2014 at 03:54

Thanks again friends for the suggestions.

By scrubbing with acid, I still have to check if I could safely dispose that acid complex.

Idea of Burning its flame with pressure, valve, etc. also scares me....

I think, as most of you suggested, I would not be having any other option except condensing the vapors and recycle.....

AvBaeyer - 17-3-2014 at 07:42

This has got to be one of the most (I hate to use the term) idiotic posts I have seen in terms of thinking through safety issues. Nobody with any sense of safety and tiny bit of chemistry experience would proceed to a pilot scale experiment utilizing diethyl ether and even think about venting it or any organic solvent for that matter into the atmosphere. Ether is one of the most no-no solvents to be used in any pilot scale experiments. Before moving from the lab bench to scale up the ether needs to be replaced by a higher boiling solvent such as, for example, toluene or an ester such as ethyl acetate or isopropyl acetate. The higher boiling solvents would then be removed from the reaction by distillation under vacuum or the reaction would be first filtered and the product dried under vacuum. The solvent/filtrate would then be recycled or sent for proper disposal. Vacuum distillation and drying techniques are common in any pilot scale facility and the equipment used for that is easily adapted or available. Enertech really needs to step back from this incipient disaster and do some more process development at the bench. I say this based on many years of chemistry experience and also having managed a process development lab and pilot plant for several years. Please do not proceed with the ether based procedure as proposed.

AvB

enertech - 17-3-2014 at 08:22

Dear AvBaeyer,

Honestly speaking, I agree with you and that is the reason why I was afraid of and wanted some advices and suggestions from some experienced people like you.

There are some limitations for me to NOT use some solvents which you suggested due to their residual contents in final product which are not acceptable even in ppm levels. That's why I went for this Ether.

But after your advice, I'd really think again and again to proceed in this project in my way.

Thanks indeed.

AvBaeyer - 18-3-2014 at 07:10

Enertech, you said:
"Actually I am doing research on pilot scale for creating a coating/film on some Inorganic Powdered oxides and Pigments (like TiO2, ZnO, Inorganic pigments like Phthalocyanine Blue/Green). The film forming material is soluble in Ether and the Powder compound is insoluble. So, I first dissolve the coating material in Ether and then just "dip" the powder fully in Ether creating a homogeneous slurry, mix it slowly to thoroughly coat the powder particles with coating agent, and then finally evaporate the ether."

I have a couple of questions:

1. Do the powders you wish to coat absorb the coating material out of solution or does the coating actually take place as a result of the evaporation process, or to to ask a bit differently, is the coating is deposited on the powders rather than absorbed? Knowing this will help you with your process design and an alternate solvent selection. With some careful analytical chemistry you should be able to obtain the answer.

2. You said above that you need solvent residues below ppm range. How do you plan to measure this? No matter what solvent you use, attaining these levels will almost certainly require a vacuum drying step. Thus, the choice of solvent is really not so important as long as your coating material is soluble. You need access to a good vacuum drying system and a robust analytical method for measuring solvent residues. Analytical methods for this can be found in the literature.

3. The solvents I mentioned above in my previous post are typical preferred process chemistry solvents. In the right facility you could also use dichloromethane (no venting!) or perhaps supercritical CO2, which can be vented. Have you considered these? A CO2 based process, assuming your coating material is soluble, would solve your solvent residue problem in a hurry but you would need to understand better the physical chemistry of your coating process (see 1, above). Supercritical CO2 processes can be very cost effective if the facility has the proper equipment.

I hope this helps your thinking process. Just get rid of that ether!

AvB

Fantasma4500 - 18-3-2014 at 10:29

evaporate it all into a massive balloon with air and release the energy -- controlled.

30 litres is quite alot tho, i would consider setting up some destillation apparatus near your factory or whatever you would call it

enertech - 19-3-2014 at 06:17

Dear AvBaeyer,

I am trying to give you answers :

1) In this project, I use some specific liquid surface-active agents (SA) which are easily soluble in Ether (and also in most other organic solvents). I just use this solvent+SA mixture to dip the powder completely, keep it for some time and mix slowly to allow the SA+solvent mixture to homogeneously cover (wet) the powder particles, and then after simply evaporating the solvent/Ether, only the powder particles coated (covered) with SA remains. This has given me excellent results generating easily hydrat able powder which readily mix with water, with very low SA content, especially when I use Ether as the solvent.

Here as the SA content is very low (less than 1% of the powder), I have to use a solvent carrier to make a quantitative coating solution to easily coat/cover the powder.

On chemistry side, I am frankly not sure about whether the SA gets absorbed or just deposited on the solid particles, but for sure, it activates the surface of solid particles to get hydrated fast!

2) To measure the solvent residue levels, I use GC-Headspace method by doing first for a pure solvent and then for the product, then comparing both the chromatograms it gives most accurate results in ppm levels for the residual solvents present. You are right again to use the vacuum drying for removal of most of the solvent, and I use it too (separately). But for Ether, removal is very fast (obviously!).

3) In this point, you have again given a very important suggestion

, like instead of using these volatile organic solvents, I should use a super critical CO2 or such alike methods. However right now I don't have any practical experience for this method, just know that it is very expensive to set up. But still can you suggest such other options/"solvents" (Not water!) in which I could just "dip" my solid powder (+SA already added & mixed with powder) and evaporate it safely to get the desired results?!

By the way, Dichloromethane is a big NO-NO for me, as any chloro solvents are not at all allowed in this.

AvBaeyer, even I want to get rid of this Ether, seriously! Please let me out!

Metacelsus - 19-3-2014 at 13:18

Ethyl acetate?
Acetone?
Petroleum ether (low-boiling aliphatic hydrocarbons)?

zed - 9-4-2014 at 13:00

Condense and recycle the ether. You cannot safely release the vapors into the atmosphere, and local safety matters aside, to do so would be illegal as hell. Keep in mind also, that if the massive cloud of vapor you would be releasing, were to somehow be ignited downwind, the fire/explosion would propagate back in your direction. Ether vapor fires like to return to the source.

Next, even in lucrative industrial processes, every cent counts. Unspeakable leftover crud, is mined for any usable component that can yield a small profit. That ether is worth a lot of money, it is a cash resource, not a nuisance.

Burner - 10-4-2014 at 18:21

What is the possibility of some peroxide formation in this situation? Without knowing the particulars it is hard to guess. If I were you I would be certain to test for peroxide formation just is case, since removing the diethyl ether may be the least of your worries. There are good reasons that diethyl ether is rarely used in pilot plants. The potential for peroxide formation is just too great a hazard, expecially when you are evaporating the final product to dryness.