Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
Author: Subject: DIY Vapor Phase Dehydration Machine - Does this Work?
LuckyWinner
Hazard to Others
***




Posts: 162
Registered: 27-8-2018
Member Is Offline


[*] posted on 10-7-2020 at 12:31
DIY Vapor Phase Dehydration Machine - Does this Work?


this is about patent
https://patentimages.storage.googleapis.com/2b/dd/41/7af81a3...
1,2-propylene glycol to propionaldehyde by Vapor Phase Dehydration

Example I An aqueous Solution containing 20% by weight of 1,2-propylene glycol is vaporized and the vapors fed at a space Velocity of 48.34 to a reaction zone heated to 970 F. and containing a mono-sodium phosphate-silicon dioxide dehydration catalyst. The catalyst in the reaction zone is formed by baking or fusing a mixture of equal parts by weight of mono-Sodium phosphate and silicon dioxide and breaking the product into Small pieces averaging about is inch in diameter. The dehydration reaction converts 92% of the feed, giving a 95% yield of propionaldehyde. Small amounts of allyl alcohol are also formed



RELATED VIDEO

CHEMPLAYER
https://www.youtube.com/watch?v=KBy_cjnMjpo
Preparation of ethanal (acetaldehyde) + Fehling's Test



my plan:

vaporize aqueous Solution containing 20% by weight of 1,2-propylene glycol inside your
RBF and lead this vapor through stainless steel tubing into your *DIY tube furnace
at 521 C which contain your catalysts mono-sodium phosphate-silicon dioxide.

exit of tube furnace is a stainless steel tube that leads into a water filled gas washing bottle ,
like in chemplayers video.
exit of gaswashing bottle is releasing hydrogen gas.

*(very easy to build in youtube)

this really works?
View user's profile View All Posts By User
Johnny Windchimes
Hazard to Self
**




Posts: 58
Registered: 28-5-2019
Member Is Offline

Mood: Sorry, it's my chimes~!

[*] posted on 30-11-2020 at 23:52


That patent's from 1950. Not saying it doesn't work, but give this newer one a look as well. The temps they use max out at about 350 - 400 C, which would let you use borosilicate tubing in your tube furnace / reactor.

This is the precise catalyst that they settled on as being the "best" in the paper, although there were many tried with similar results.


I'm in the process of trying it out myself, I'll keep you posted!


***EDIT*** ZSM-5 was NOT their "best" catalyst, but it is the one that is as close to their best (within like 3% conversion and selectivity) that is commerical off-the-shelf ready, and DOES NOT require fancy prep and calcination and such, like their actual "best", ZSM-23 and Theta-1 zeolites.


Attachment: Dehydration-of-12-propanediol-to-propionaldehyde-over-zeolite-catalysts8647 - Copy.pdf (928kB)
This file has been downloaded 134 times

Attachment: zeolyst propanal - Copy.pdf (326kB)
This file has been downloaded 138 times

[Edited on 1-12-2020 by Johnny Windchimes]




~Incredibly profound and/or wise quote goes here~
View user's profile View All Posts By User
Johnny Windchimes
Hazard to Self
**




Posts: 58
Registered: 28-5-2019
Member Is Offline

Mood: Sorry, it's my chimes~!

[*] posted on 1-12-2020 at 12:27
Game Chaaaaaanger


If you can prep the Ruthenium on Alumina catalyst which, as of this date of posting, are both fairly reasonable items on ebay; this my friend is the ticket.

Reflux, 97 degrees C, no tube furnace, no high temps.



In fact it's so much the ticket I've scrapped my vapour phase zeolite plans for propionaldehyde entirely:o

Attachment: disselkamp2008 - Copy.pdf (88kB)
This file has been downloaded 181 times

[Edited on 1-12-2020 by Johnny Windchimes]




~Incredibly profound and/or wise quote goes here~
View user's profile View All Posts By User
Mateo_swe
National Hazard
****




Posts: 423
Registered: 24-8-2019
Location: Within EU
Member Is Offline


[*] posted on 1-12-2020 at 14:29


I read in the disselkamp2008 - Copy.pdf paper "It is seen that both propanal and 1,3-dioxolane-2-ethyl-4-methyl concentrations are comparable during the course of the reaction, and that they both achieve a maximum at 1.5 H2O2 equivalents.".
and "The combined yield at 1.5 equivalents H2O2 is computed to be 3.1%".

So even if this works the propanal yield is about 1,55% as both products are formed in equal amounts.
There must be a better way to make the propanal, maybe the tube furnace wasnt such a bad idea after all.
What about the method from Propionaldehyde wiki:
Propionaldehyde can be prepared by oxidizing 1-propanol with a mixture of sulfuric acid and potassium dichromate.
https://doi.org/10.15227%2Forgsyn.012.0064
View user's profile View All Posts By User
Johnny Windchimes
Hazard to Self
**




Posts: 58
Registered: 28-5-2019
Member Is Offline

Mood: Sorry, it's my chimes~!

[*] posted on 1-12-2020 at 15:28


Quote: Originally posted by Mateo_swe  
I read in the disselkamp2008 - Copy.pdf paper "It is seen that both propanal and 1,3-dioxolane-2-ethyl-4-methyl concentrations are comparable during the course of the reaction, and that they both achieve a maximum at 1.5 H2O2 equivalents.".
and "The combined yield at 1.5 equivalents H2O2 is computed to be 3.1%".

So even if this works the propanal yield is about 1,55% as both products are formed in equal amounts.
There must be a better way to make the propanal, maybe the tube furnace wasnt such a bad idea after all.
What about the method from Propionaldehyde wiki:
Propionaldehyde can be prepared by oxidizing 1-propanol with a mixture of sulfuric acid and potassium dichromate.
https://doi.org/10.15227%2Forgsyn.012.0064


Oh yeah, full disclosure, I was on a plane skimming this downloaded .PDF style and as I wear glasses, my COVID mask was fogging me up..... so yeah.... that's my official excuse for reading 31%, not the actual 3.1% yield....

The actual reason is I'm stupid, got REALLY excited, and didn't notice this error even several hours later, until I read the above response in fact and was very puzzled.....

There goes 8 hours of Ruthenium Alumina research lol....:(

I'm going to leave it unedited above because hey, we all need a laugh right?:P

In a similar vein of 3% yield..... I leave you with this Masters Thesis. Skip to page 40 for his version of the Ruthenium Alumina reflux one-pot over various catalysts. He was gunning for Propylene Oxide in his thesis, but it doesn't matter because the mishmash he got was basically moot....

Back to the tube furnace method I trot!



Attachment: Masters Thesis - Copy.pdf (880kB)
This file has been downloaded 171 times





~Incredibly profound and/or wise quote goes here~
View user's profile View All Posts By User
Johnny Windchimes
Hazard to Self
**




Posts: 58
Registered: 28-5-2019
Member Is Offline

Mood: Sorry, it's my chimes~!

[*] posted on 10-12-2020 at 16:12


This looks like the ticket for at home chemistry, avoiding chromium compounds and vapour phase setups:



Courtesy of The Vespiary~

Attachment: US2775623 - Copy.pdf (367kB)
This file has been downloaded 172 times





~Incredibly profound and/or wise quote goes here~
View user's profile View All Posts By User

  Go To Top