LuckyWinner
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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?
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Johnny Windchimes
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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 226 times
Attachment: zeolyst propanal - Copy.pdf (326kB)
This file has been downloaded 227 times
[Edited on 1-12-2020 by Johnny Windchimes]
~Incredibly profound and/or wise quote goes here~
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Johnny Windchimes
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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
Attachment: disselkamp2008 - Copy.pdf (88kB)
This file has been downloaded 377 times
[Edited on 1-12-2020 by Johnny Windchimes]
~Incredibly profound and/or wise quote goes here~
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Mateo_swe
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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
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Johnny Windchimes
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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
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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?
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)
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Johnny Windchimes
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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 257 times
~Incredibly profound and/or wise quote goes here~
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