Sciencemadness Discussion Board - Acetone from calcium acetate

Acetone from calcium acetate

symboom - 1-5-2011 at 14:05

btw i know i can just buy acetone from the hardware store.
i have dissolved some seashells in vinegar. which is the strangest things first time seeing seashells dissolve in an acid. Don't worry no crustations weren't in them
and it should form calcium acetate. any ideas how the best way to make the acetone from there. Im guessing just heat it to decomposition to form acetone then condense it with salt ice water bath. Also whats it decompose to acetone and what else is the calcium compound left over calcium oxide?
not sure what the decomposition reaction is for this.

ScienceSquirrel - 1-5-2011 at 14:59

Vinegar is less than 6% acetic acid and not all of it will have reacted.
But do the calculations on the basis of how much vinegar you used and work out your theoretical yield of calcium acetate.
The next step is to boil down the solution and dry your calcium acetate. Work out how much energy this requires!
Put this in to a suitable container and heat until pyrolysis takes place, yields are crap. Ten grams of calcium acetate will yield a few ml of impure acetone under best conditions.
Redistil your acetone and work out how much it has cost you per ml.
Realise that you could have bought a litre of acetone for the cost of your vinegar, electricity, etc and still had change for a pint and a pizza

Hexagon - 1-5-2011 at 15:30

Man he said he already knows he can get acetone for cheap out of the hardware store so that implies he is just doing it for fun or academical pourposes...

bbartlog - 1-5-2011 at 17:40

Quote:

what else is the calcium compound left over calcium oxide?

Calcium carbonate. The idealized reaction is
Ca(CH3COO)2 -> CaCO3 + C3H6O
You need a fair bit of heat to drive the reaction; 350C at least and 450-500C would be better unless you have a lot of time to waste. I tried this same reaction at around 250C and got nothing.

symboom - 1-5-2011 at 18:50

that's interesting you end up with Calcium Carbonate again? calcium carbonate and acetic acid actually mine is more like 5% or more but more like 5.01% the way they short change it as vinegar has to be a certain %
i was interested on the old fashion way they made it.

[Edited on 2-5-2011 by symboom]

Waffles SS - 13-1-2012 at 01:28

I like to try this reaction but i think:
-This is impossible to use glass rbf for this purpose(500C)(i should use stainless steel flask)
-Flask should be free of any oxygen otherwise acetone will fire and flask will explode.(i should use inert gas or i should use vacuum)
-Common burner cant provide 500C and i should use special electrical heater
-Produced Acetone should cool rapidly otherwise Self-condensation will occur(i should use inert gas for speedup acetone exit and cooling)
..

Cloner - 13-1-2012 at 05:00

I suggest the use of pyrex test tubes if you have them. They allow much greater temperatures to be reached than RBF's. Calcium carbonate will go to red hot if heated in one of those.

cyanureeves - 13-1-2012 at 05:24

in spite of ScienceSquirrel saying it was not worth it, he did provide the instruction. 1 ml?you're better off selling pickled seashell by the seashore . if i was ever stranded on a distant island and had three picks of company, i'd pick symboom for his raw ideas and ScienceSquirrel for know how and a RBF.

AirCowPeaCock - 13-1-2012 at 11:21

Quote: Originally posted by cyanureeves

in spite of ScienceSquirrel saying it was not worth it, he did provide the instruction. 1 ml?you're better off selling pickled seashell by the seashore . if i was ever stranded on a distant island and had three picks of company, i'd pick symboom for his raw ideas and ScienceSquirrel for know how and a RBF.

I don't know if your going to get very far without a burner, I'd say drop the RBF and get the burner, You could make all sorts of glassware with sand and the burner--might be a bit opaque though..hahaha

Further more, I don't think the synthesis is for any purpose than just to do it. Of course he/she could go out and buy a liter of Acetone for pocket change, but that's not the point--Its for the science...and fun!

[Edited on 1-13-2012 by AirCowPeaCock]

ScienceSquirrel - 13-1-2012 at 14:50

There are lots of things that are more fun, colourful and easier to synthesise.
Make some alums, double or complex salts.
Cheaper and more interesting than making a readily available organic solvent in low yield at high cost.

Hexavalent - 13-1-2012 at 15:14

Agreed, it shouldn't be used if you have the intention of large-volume production but might just be nice for a prove-the-point experiment. You could use some permangante and test for no discoloration with your acetone, as it is a ketone and won't be oxidised by the KMnO4 any further, resulting in no oxidation or reduction of the KMnO4 and consequently no colour change.

AirCowPeaCock - 13-1-2012 at 15:19

If he has KMnO4 at his disposal..I certainly don't, although I should. Maybe NaCO3.1.5H2O2? But that might create a peroxide group slowly

vmelkon - 27-1-2012 at 10:45

I have tried this myself and uploaded a video to youtube but they blocked my video with a warning. I'm not sure why.

Yes, you do have to dry you calcium acetate. You can either leave it out in air or dry it with a heater. One way cost a lot of time and the other costs an energy source.

You should heat at around 300 C. I used pyrex distillation setup.
White fumes form in the condenser but they conglomerate into drops.

The smell is weird. It smells like some kind of heavy hydrocarbon.

Once you finish, you end up with CaCO3 again.
You can drop more acid and see it fizz again.

Waffles SS - 27-1-2012 at 22:27

Quote: Originally posted by vmelkon

I have tried this myself and uploaded a video to youtube but they blocked my video with a warning. I'm not sure why.

Yes, you do have to dry you calcium acetate. You can either leave it out in air or dry it with a heater. One way cost a lot of time and the other costs an energy source.

You should heat at around 300 C. I used pyrex distillation setup.
White fumes form in the condenser but they conglomerate into drops.

The smell is weird. It smells like some kind of heavy hydrocarbon.

Once you finish, you end up with CaCO3 again.
You can drop more acid and see it fizz again.

I Dont think at 300c thermal decompose occur.Can you explain your try( Ratio and your Yield)?

vmelkon - 29-1-2012 at 04:30

For heating, the first few times I used coal.
For the next few runs, I used 2 halogen bulbs in parallel (500 W and a 300 W). To my surprise, the halogen is does the job just as well.

I didn't take measurements since I didn't consider this experiment important

I'm going to try again sometime.

Waffles SS - 2-2-2012 at 09:19

I think barium acetate Pyrolysis should be more interesting(it decompose on 150C)

Quote:

When barium acetate is pyrolyzed it decomposes, forming acetone and barium oxide as pyrolysis products. Often, during the
heating, the acetone vapors catch fire and/or explode, and the further production of acetone is catalyzed by the barium oxide.
Melting point (decomposes): 150 °C

Jay A. Young
Chemical Consultant, Silver Spring, MD 20904-3105
J. Chem. Educ., 2006, 83 (3), p 380
DOI: 10.1021/ed083p380
Publication Date (Web): March 1, 2006

http://pubs.acs.org/doi/abs/10.1021/ed083p380

AirCowPeaCock - 2-2-2012 at 11:28

Would need to evacuate the dist app though, but I suppose you would probably want to do that for Ca(AcO)<sub>2</sub>

According to Wiki Ca(AcO)<sub>2</sub> decomposes at 160 C

[Edited on 2-2-2012 by AirCowPeaCock]

Waffles SS - 2-2-2012 at 12:16

Ca(AcO)2 decompose at 400-500C(i tried it.wiki is wrong)

The thermal decomposition of calcium, sodium, silver and copper(II) acetates
Journal of Thermal Analysis and Calorimetry
M. D. Judd, B. A. Plunkett and M. I. Pope
Volume 6, Number 5, 555-563,
DOI: 10.1007/BF01911560
http://www.springerlink.com/content/p637804801j11425/

AirCowPeaCock - 2-2-2012 at 13:41

I frequently find wiki wrong on melting/boiling points, decomps, and solubility--but everything else seems to be in-order. Why the fuck would this be, are assholes just pulling numbers out of their asshole? Not to long ago I caught wiki saying NaCl has a solubility of something along the lines of 500 g / 100 ml

Waffles SS - 3-2-2012 at 20:58

Quote:

Kinetics of thermal decomposition of metal acetates

M. Afzal, P. K Butt and H. Ahmad
http://www.springerlink.com/content/m13n803140pm50p4/

Interesting result by pyrolysis of Nickel Acetate(Diacetyl produced)
I like to know effect of vacuum in Nickel acetate Pyrolysis

AndersHoveland - 27-3-2012 at 01:12

The thermal decomposition of sodium acetate forms acetone.
Adding sodium hydroxide to sodium acetate, then thermally decomposing, forms methane instead.
In both instances, sodium carbonate forms as a byproduct.

Aperturescience27 - 6-6-2012 at 12:20

What about using magnesium acetate? Seems simple enough, and according to Waffles SS's chart, it decomposes between 275 and 340 C. Still pretty high, but better than calcium.

AndersHoveland - 6-6-2012 at 22:18

Quote: Originally posted by Aperturescience27

What about using magnesium acetate? Seems simple enough, and according to Waffles SS's chart, it decomposes between 275 and 340 C. Still pretty high, but better than calcium.

The hydrate of magnesium acetate loses water to become fully anhydrous above 150 °C. The anhydrous magnesium acetate then decomposes into MgO, acetone, and CO2 at 275 to 340 °C.
"Kinetics of thermal decomposition of metal acetates", M. Afzal (Pakistan)

(note that the hydrate of magnesium nitrate decomposes into nitrogen oxides rather than giving up water)

[Edited on 7-6-2012 by AndersHoveland]

Aperturescience27 - 5-9-2012 at 01:43

Quote: Originally posted by AndersHoveland

Quote: Originally posted by Aperturescience27

What about using magnesium acetate? Seems simple enough, and according to Waffles SS's chart, it decomposes between 275 and 340 C. Still pretty high, but better than calcium.

Are you agreeing with me? I don't see anything there that would be a problem. I think I might try this, actually.

bbartlog - 5-9-2012 at 05:48

In 'The pyrolysis of carbon compounds' Hurd gives a temperature range of 330-360C for magnesium acetate. He also (on p482) lists the following yields of acetone for pyrolysis of various acetate salts, which are from Krönig (Z. angew. Chem. 1924):

Lithium acetate: 100% (contradicted elsewhere in the text where he gives a 93% figure)
Barium 89%
Calcium 83% (but elsewhere 90-100% is claimed if inert gas sweeping is used)
Magnesium 76% (elsewhere 57% is claimed)
Manganese(II) 66%
Sodium 37% (elsewhere 50%)
Potassium 12%
Lead 87%

Hurd gives no complete list of temperature ranges for decomposition of all these salts, but it may be that Krönig's original paper has some such information.

byko3y - 29-7-2015 at 16:15

I was wondering how good is the magnesium acetate for pyrolysis.
I've made an attempt to heat 0.5 mole (40 g) of magnesium acetate at 350-400°C using a slight flow of CO2 (approx 0.3 L/hour) to sweep the gases from reactor. This led to 35 ml of distillate (magnesium acetate was not completely anhydrous) and a lot of fumes easily passing condenser and making clouds in the receiving flask. Distillate had no layers (even after I've added NaCl to salt out acetone), but the liquid had yellow color at top, while bottom was completely clear.
After I've added NaCl, small amount of NaHCO3, 15 ml of ethyl acetate, I mixed this stuff a bit and then it separated into 25 ml of top yellow layer (+10ml of something) and clear bottom layer. The top yellow layer has horrible smell.
I remember I tried to make acetone by oxidation using NaOCl + acetic acid, and I've got pretty much the same stincky liquid plus a lot of clouds of non-condensable compound when the source flask was heated strong enough (there was some non-volatile liquid left, so I was trying to distill it too).
What was the volatile gas? Could it be a ketene? I have no idea.
If I assume that the acetone moved to the ethyl acetate layer and all the 10 ml volume is acetone, then I've got 8 g/130 mmol of acetone, which is 25% yield. Probably I should have used more strong current of CO2, something like 2L/h. Or maybe make sure the magnesium carbonate has no traces of acetic acid.
I'm gonna try to perform fractional distillation of the ethyl acetate part.

[Edited on 30-7-2015 by byko3y]

Pumukli - 31-7-2015 at 01:28

Interesting experiment.

What sort of "horrid smell" did you feel?
Was it kind of suffocating e.g. like formaldehyde? Was it simply nauseating like a decomposing dead rat in a storage box?
Of course the answer will not shed more light on what the reaction produced, I'm simply curious. :-)

The use of Mg is interesting, though in the literature they prefer Ca or Ba if I remember well.

How do you plan to investigate the product further?

kecskesajt - 1-8-2015 at 02:52

Maybe it wasn't so inert gas or had other metals in there and the acetone pyrolised into ketene.

byko3y - 4-8-2015 at 21:59

Finally I've finished the separation of the product. I needed to calibrate my distillation column, it appeared to provide 3-5 theroretical plates (40 cm vigrex column with), so I needed at least 2 distillations to obtain a relatively pure acetone.
So the isolated yield is 1.5 ml (20 mmol) out of possible 18 g (300 mmol). Also, I've got 2.5 ml of some high boling liquid, wich contains acetic acid, I'd say it has 1.5 ml/13mmol of mesityl oxide. I'm pretty sure the actual yield of acetone was 3-4 ml, but I've lost some amount during purification. Anyway, it's 10-15% yield of acetone plus 10% yield of polymertization products (100% yield is a quantitive conversion to either acetone or polymers), and 80% decomposition products.

Pumukli, the smell is very similar to the acetone, some heavy slightly irritating flower odor, it felt like the whole house was filled with acetone, although I'm sure my device had no leaks - the clouds were coming from the outlet, and not anywhere else. And yes, I felt some dizziness breathing those gases. I would not say it's very similar to an odor of decomposing body.
Calcium acetate requires at least 400°C for decomposition to take place, and 400°C is the upper limit for my glass devices. I could rich 500-550°C by heating from all sides, but for now I have only a regular heating plate, and I've detected it to be as hot as 450 °C while the temperature inside the flask was barely reaching 400°C. I think some amount of polymers were left in the flask (it had the characteristic odor of polymeric products).
I'm gonna try to use a stronger flow of CO2 through the mixture, also I'm gonna need a higer temperature because the gas will cool the reactor. I did not dry the magnesium acetate well, this might be another reason for the failure.
AFAIK, MgO is a relatively strong base, but Mg(OH)2 is insoluble in water, that's why its solution in water cannot be really basic, but the freshly prepared (activated) magnesiu is caustic, that's why it seems readily cause polymerization.

I was not able to find data for decomposition of barium acetate and nobody seems to ever try it. I'm not really willing to perform the experiment because barium has a notable toxicity. Thorpe mentiones that calcium acetate needs higher temperature for decomposition, patent US 648,389 tells about 300°C for barium salt and 400°C for calcium salt. Here's a picture for calcium acetate:

UPD: some more data on pyrolysis temperatures:
http://pubs.rsc.org/en/content/articlelanding/1952/jr/jr9520...
DOI: 10.1039/JR9520001383
"Experiments with non-isotopic materials showed that the decomposition of barium acetate proceeded rapidly only at temperatures above 440°C. In the pyrolysis of calcium acetate Ardagh, Barbour, McClellan, and McBride (Id. Eng. Chem, 1924, 16, 1133) reported that this reaction only became rapid at temperatures around 430°C although small traces of acetone were formed at temperatures as low as 160°C".

[Edited on 5-8-2015 by byko3y]

Nicodem - 5-8-2015 at 01:27

How do you currently condense acetone in the flow of carbon dioxide? If you increase the flow, you will have to use a trap cooled with a dry ice in acetone bath. I mean, obviously you cannot use cold water as the partial pressure of acetone is about 90 mbar even at 0 °C. It therefore takes a very low flow of carbon dioxide to obtain a partial recovery of acetone with ice cold water cooling. With the flow increased you will not be able to condense it with cold water.

byko3y - 5-8-2015 at 02:14

In fact I was thinking about that when deciding what flow I should use. Later I forgot about this problem, and authors of the articles I have read just used hypohalite/bisulfite traps.
In fact I was using 25°C water for cooling, and acetone has insane 200 mmHg vapor pressure at this temperature. During the experiment I was trying to cool the water little bit but I got only 10-15°C and this led to 150 mmHg vapor pressure. While amount of CO2 used was 0.3L/h, the decomposition products had much higher volume, and if we suppose their amount to be 20% of the molar amount of acetate, than their volume was ~2L.
2.3 L can carry up to 26 mmol of acetone vapors, which is the half of the yield I've got, and this used to be a common reason for lower than quantitive yield of acetone in former times.
My data tells me that acetone vapor pressure at 0°C is 70 mmHg, which is acceptable for 2-3 L/h gas flow (10 mmol/0.6g loses per hour). Most basic water pumps are made from plastic, and for polypropylene the lowest temperature is -15..-5°C. A slightly salted water with ice will provide -5°C (50 mmHg acetone), and I would not bother catching the residual vapors.

[Edited on 5-8-2015 by byko3y]