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Author: Subject: keten lamp
not_important
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[*] posted on 30-3-2008 at 06:09


Quote:
Originally posted by hector2000
I am Wonder How Acetyle chloride React With Steel(318) wheras Pure Nitric Acid Cant.! :o


Strong nitric acid, an oxidising agent, forms a passivated layer on the surface of the metal.

Acetyl chloride is not an oxidising agent, but will form HCl from traces of moisture; both HCl and soluble chlorides are notoriously corrosive to ferrous alloys.
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hector2000
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[*] posted on 31-3-2008 at 00:02


THEREFORE We Cant Use Steel Container?
This Is Possible That We Use of Steel with coat of Gold or platinum or nickel?
May Acetyle Chloride React With them?
What is Your Suggestion?

[Edited on 31-3-2008 by hector2000]




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hector2000
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[*] posted on 3-4-2008 at 05:51


Anybody has idea about steel 321?
This type of steel is very RESISTANT for acids.




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S.C. Wack
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[*] posted on 2-9-2008 at 01:43


And eventually...the original article on acetic anhydride from ketene.

[Edited on 2-9-2008 by S.C. Wack]

Attachment: jacs_54_3427_1932.pdf (351kB)
This file has been downloaded 796 times

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einstein(not)
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[*] posted on 19-5-2009 at 18:06


Sorry in adavance if I've missed the answer to my question. Can copper be used in a tube furnace for ketene? I'm asking because of this http://jchemed.chem.wisc.edu/JCEsoft/CCA/CCA5/MAIN/1ORGANIC/...
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[*] posted on 19-5-2009 at 18:55


Copper can be used.

See this thread with pictures where I did it.
https://www.sciencemadness.org/whisper/viewthread.php?tid=74...

We have some FTIR scans of the gas cell kicking around...somewhere. It does work, and it would probably work half decent if you had a very large tube to do it--perhaps liters per day.

Make sure you don't make an ass of yourself by not closing your tube up properly as I can assure you it is flammable and smells something awful. :P

This is an experiment I really want to repeat sometime.




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[*] posted on 19-5-2009 at 21:33



you can use stainless steel 304, because if you gonna make a pipe bomb is teh best stainless steel to welding and for more info look the link below :D
http://en.wikipedia.org/wiki/Stainless_steel
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[*] posted on 19-5-2009 at 22:29


You can use stainless steel, but most of the research papers report low to zero yields of ketene when using ferrous tubing; from experience ferrous alloys do seem to catalyse cracking to carbon while copper does not do so.
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[*] posted on 30-12-2015 at 17:48


I want to congratulate Praxichys on his construction of an ingeniously simple ketene lamp and successful synthesis of acetic anhydride using this lamp. This can be seen at Doug's Lab on YouTube.



The single most important condition for a successful synthesis is good mixing - Nicodem
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hector2000
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[*] posted on 31-12-2015 at 05:27


finally good news after 8 years.

respect for all people who share information on this topic.

especial thanks to @Sauron,@Nicodem,@not_important and @Praxichys for movie on youtube.



[Edited on 31-12-2015 by hector2000]




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[*] posted on 4-1-2016 at 11:15


My old Facilities for making Keten by Furnace (6 years ago):

1.jpg - 88kB
2.jpg - 88kB
3.jpg - 103kB

And now by keten lamp(in my lab):

4.jpg - 403kB


[Edited on 4-1-2016 by Waffles SS]
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[*] posted on 4-1-2016 at 11:50


@ Magpie: Thank you! I'm working on an article for prepublication to commit it to the annals of SM.

@ Waffles: Wow, that is a proper ketene lamp. What are you using for the heating element? I like how you used a schlenk flask with a septum for the acetone reservoir, probably so you can inject more acetone while it's running? Very nice!




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[*] posted on 5-1-2016 at 09:34


Thanks Praxichys,

I used 2.5mm diameter Ni/Cr wire and i built this system according to Vogel Keten lab instruction.(Vol.3,p372-373)

[Edited on 5-1-2016 by Waffles SS]
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[*] posted on 27-10-2017 at 06:17


Can anyone tell me what to do if I was to be using a ketene lamp setup identical to Praxichys video on youtube and finding it hard to get the sweet spot between no ketene being made and white smoke filling the rbf trap for byproducts etc and going through to the gaa absorbtion tube. I assume this smoke is not good but cant seem to find a voltage setting that will produce enough bubbles to do anything but not create this white smoke.
Any ideas? I had it running for 3 hours the other day and only ended up with approx 10 mls of product after fractionating.
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[*] posted on 1-11-2017 at 17:23
New lamp


Well I went to fire it up again and have noticed a crack starting at the bottom of the chratography reservoir.......the wire element was too close to the glass and thermal expansion etc.....so I was stuck until another arrives in a week or two until I looked over at a friedrichs condenser that arrived with the inner finger broken off by customs (arseholes!).....I figured if I could hollow out all the inner workings then I could feed the two wires for the coil down the old water nipples and epoxy the holes shut.....can always pick it out if need be. I'll attach some pics but unfortunately you cant see through the glass very well as it got etched as I hollowed out the inner workings. What do you think?

[Edited on 2-11-2017 by NZniceguy]

IMG_20171102_140952.jpg - 3.8MBIMG_20171102_141004.jpg - 3.8MB
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[*] posted on 2-11-2017 at 03:11


Looks promising. What about a glass wool lining to protect the tube from the hot filament?

Glass certainly has it's problems dealing with high temperatures. I've been thinking about constructing an all-metal reactor lately to avoid such problems entirely. The thought of ketene and acetone vapor in the case of a failure isn't all that inviting.
One thing confuses me though. In a document I found (564 Schmidlin Ketene Synthesis, can't remember from where) they claim "this reaction cannot be conducted through a metal tube, either a copper tube or an iron pipe because carbon may form via dehydrogenation in the presence of some metal oxides." Yet the standard ketene lamp uses hot metal wire. Or is this avoidable by careful temperature control?
Except for the hot zone most metals should be compatible, right?




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[*] posted on 2-11-2017 at 04:40


Quote:
In a document I found (564 Schmidlin Ketene Synthesis, can't remember from where) they claim "this reaction cannot be conducted through a metal tube, either a copper tube or an iron pipe because carbon may form via dehydrogenation in the presence of some metal oxides

The glass in this set-up can be replaced by 430 SS tubing ─ copper, too, will work but won't last as long due to slow oxidation at high temp..


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[*] posted on 24-11-2017 at 23:47


If even some of the acetone vapour made it through and ended up condensing into the end mixture, wouldnt it then dissolve the ketene (with ketene being soluble in acetone) therefore preventing full conversion of the acetic acid?
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[*] posted on 25-11-2017 at 03:16


Indeed, an efficient condenser is required in any case.


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[*] posted on 27-12-2017 at 23:48


NZniceguy.....you've got far too much wire coiled up in there...odds are that you are over cooking everything...you want a dull red heat, that is, in a dimly lit room you can barely just see a deep red glow coming off that wire...have you got a infra red type thermometer ? I'm not sure how accurate those are, but it might help you get the temp dialed in. I had a similar problem to this in another pyrolytic process, and I was getting this white mist condensate..long story short too high on the temp....You might want to rip out that coil and try using only like a quarter of that amount of wire, the whole thing is just over kill...trust me on this...my fellow kiwi...
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[*] posted on 28-12-2017 at 20:48


Quote: Originally posted by sykronizer  
NZniceguy.....you've got far too much wire coiled up in there...odds are that you are over cooking everything...you want a dull red heat, that is, in a dimly lit room you can barely just see a deep red glow coming off that wire...have you got a infra red type thermometer ? I'm not sure how accurate those are, but it might help you get the temp dialed in. I had a similar problem to this in another pyrolytic process, and I was getting this white mist condensate..long story short too high on the temp....You might want to rip out that coil and try using only like a quarter of that amount of wire, the whole thing is just over kill...trust me on this...my fellow kiwi...


Be careful...if you take out wire without lowering the voltage you will actually increase the temperature. For a wonderful ketene lamp see Doug's Lab YouTube video.




The single most important condition for a successful synthesis is good mixing - Nicodem
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[*] posted on 2-1-2018 at 20:01


Quote: Originally posted by sykronizer  
NZniceguy.....you've got far too much wire coiled up in there...odds are that you are over cooking everything...you want a dull red heat, that is, in a dimly lit room you can barely just see a deep red glow coming off that wire...have you got a infra red type thermometer ? I'm not sure how accurate those are, but it might help you get the temp dialed in. I had a similar problem to this in another pyrolytic process, and I was getting this white mist condensate..long story short too high on the temp....You might want to rip out that coil and try using only like a quarter of that amount of wire, the whole thing is just over kill...trust me on this...my fellow kiwi...


Thanks for that info, that lamp ended up cracking after the 2nd use so I went back to the 250ml chromatography reservoir ala the Dougs Lab video but maybe I still have too much heat as its still not dialed in quite right...I also tried putting the acetone/byproducts trap in an icebath to try stop any acetone coming over into the G.A.A. I havnt tried it in a week or so but must try again sometime soon..........the voltage doesnt matter as im running it on a motor speed controller and just crank it up till I get bubbles coming through the g.a.a. but it does seem like the element is redder than in the video and as you describe but any lower and i lose the bubbles/ketene (checked for leaks also).......Ive tried an infra red thermometer but it doesnt seem to work through the glass damnit!
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