Sciencemadness Discussion Board

making ethylene

Magpie - 30-11-2018 at 18:23

Today I made ethylene using a tube furnace packed with 6" of alumina BBs. The BBs are BASF F200, 1/8" in diameter held in place with 1/8" mesh ss screens on both ends. The ethanol feed is 95% ethanol (Everclear). The system was first purged with argon. The ethylene was caputured underwater using the 2 gas bottles shown. When lit the gas burned like a candle with a somewhat sooty flame. I intended to do unsaturation tests with Br2 water and KMnO4 water but did not have these reagents prepared. The furnace temperature was held at 469°C using a PID controller. The ethanol was kept at a low boil.

See next post for 2 additional pictures.



ethanol vaporizer.JPG - 2.1MB furnace temperature.JPG - 2.6MB

[Edited on 1-12-2018 by Magpie]

[Edited on 1-12-2018 by Magpie]

[Edited on 1-12-2018 by Magpie]

Magpie - 30-11-2018 at 18:38



condenser.JPG - 1.9MB gas bottles.JPG - 2MB

symboom - 30-11-2018 at 18:48

Photos are downside up
Great experiment ethylene from everclear :cool:

So if you mixed in silver with the catalysis it seems strait forward to produce ethylene oxide right?

Excerpt
Ethylene oxide is industrially produced by oxidation of ethylene in the presence of silver catalyst.



[Edited on 1-12-2018 by symboom]

Magpie - 30-11-2018 at 18:59

Toggle the pictures. They will invert.

morganbw - 1-12-2018 at 06:39

Nice

Magpie - 1-12-2018 at 09:17

Quote: Originally posted by symboom  


So if you mixed in silver with the catalysis it seems strait forward to produce ethylene oxide right?


This would be a very useful reagent. But how would you integrate the silver with alumina BBs?

UC235 - 1-12-2018 at 09:29

Quote: Originally posted by Magpie  
Quote: Originally posted by symboom  


So if you mixed in silver with the catalysis it seems strait forward to produce ethylene oxide right?


This would be a very useful reagent. But how would you integrate the silver with alumina BBs?


I would probably soak them in AgNO3 solution, bake dry, and heat strongly to decomposition to produce metallic silver and/or Ag2O.

Magpie - 1-12-2018 at 09:42

Good suggestion - thanks.

The BBs get heated strongly during furnace heat-up to 469°C.

Heptylene - 2-12-2018 at 01:52

Nice setup Magpie! Do you plan to use the ethylene in another reaction?

Magpie - 2-12-2018 at 06:17

Yes, I hope to make diethyl sulfate using con sulfuric acid.

WGTR - 2-12-2018 at 09:36

Nice setup Magpie. It's nice to see some high temperature tube furnace chemistry. This setup is much cleaner than heating ethanol with sulfuric acid, with lower materials cost and fewer waste products for sure.

Magpie - 2-12-2018 at 12:37

Thanks to both of you. Yes, this synthesis seems to be very clean. There was a few ml of liquid in the knock-out pot below the condenser. It did not smell of unconverted ethanol. Also, I smelled no ether. The run I made was very short.

Magpie - 5-12-2018 at 14:31

Here's the results of the Baeyer test (aqueous KMnO4) and the alcoholic I2 test for unsaturation:

Baeyer and alcoholic I2 test results.JPG - 2.2MB

The Baeyer test worked well as the intensely purple solution immediately turned brown. For some reason the I2 test did not work as there was no color change.

[Edited on 5-12-2018 by Magpie]

UC235 - 5-12-2018 at 15:07

I don't think Iodine is typically able to add across double bonds. In fact, you can dehalogenate a vicinal dibromide with KI in a polar solvent. After a substitution, I2 or possibly IBr is ejected. Bromine is the best option for an unsaturation test.

jerryhall - 6-12-2018 at 22:47

Nice setup

wakatutu - 6-12-2018 at 23:54

@UC235 - regarding the dehalogenation of vicinal dihalides using NaI in a polar solvent - do you think this is possible to perform on DCM using NaBr in DCM, leading to the formation of the methylene radical?