| Pages:
1
..
10
11
12
13
14 |
Fashist
Hazard to Self
Posts: 73
Registered: 19-7-2007
Member Is Offline
Mood: Powerful
|
|
If this Reaction need heat then why mr Nerv used of ice in his system?
Really if this reaction is CALEFACTORY then the method must be same in all project.
(i know many reaction between gas and liquid then need CHILL no heat!)
[Edited on 11-12-2007 by Fashist]
|
|
|
Fleaker
International Hazard
Posts: 1252
Registered: 19-6-2005
Member Is Offline
Mood: nucleophilic
|
|
We added ice because a lot ketene and was escaping out of the second wash bottle tower filled with water. We could tell this by the smell. When we
added ice to the GAA-filled ''absorber'' there was no ketene out the second water-filled absorber. I can only presume that decreased temperature of
GAA lead to more ketene solubility or at least a longer residence time in the GAA. But it also means a slower reaction with the GAA so there is
probably a point of diminishing returns. I can not say at what scale it is advantageous to cool or to heat your glacial acetic acid, but for us, we
found that the least amount of ketene escaped the system when it was cooled.
Edit: It should be noticed that the Acetic acid never got above 30*C; we did NOT try it hot. I suppose we could have heated our absorption vessel with
heating tape and tried it that way. It will probably be better to do it that way.
[Edited on 11-12-2007 by Fleaker]
Neither flask nor beaker.
"Kid, you don't even know just what you don't know. "
--The Dark Lord Sauron
|
|
|
not_important
International Hazard
Posts: 3873
Registered: 21-7-2006
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by Fashist
If this Reaction need heat then why mr Nerv used of ice in his system?
Really if this reaction is CALEFACTORY then the method must be same in all project.
|
You can calculate the heat of reaction between ketene and acetic acid, standard textbook chemistry; the heat of formation of ketene given before 1980
or so is not correct.
There are other things besides a reaction being exothermic or endothermic that affect how it goes.
The pilot plant document runs the absorption at about 80 C for several reasons; this was done to get best performance. Cooling the acetic acid with
ice won't prevent the reaction from taking place. It may have some effect on the performance of the system, but on a small scale benchtop system that
is not out to optimise performance that difference might be unimportant to the operators of the equipment.
Remember the motto of Perl....
|
|
|
WizardX
Hazard to Self
Posts: 61
Registered: 11-8-2005
Location: wizardx.4shared.com
Member Is Offline
Mood: wizardx.suddenlaunch3.com
|
|
(1) Generation of Ketene With High Quantum Yield by a KrF Laser.
[Edited on 12-12-2007 by WizardX]
Attachment: Generation of Ketene With High Quantum Yield by a KrF Laser.pdf (1.2MB)
This file has been downloaded 988 times
|
|
|
WizardX
Hazard to Self
Posts: 61
Registered: 11-8-2005
Location: wizardx.4shared.com
Member Is Offline
Mood: wizardx.suddenlaunch3.com
|
|
(2) United States Patent 4455439
In this process for the preparation of ketene by the thermal, catalytic cracking of acetic acid under reduced pressure, the hot cracked gases
are cooled to approx. 0° to -10° C. and, in the course thereof, water, unreacted acetic acid and acetic anhydride are condensed. The
quantity of acetic acid employed for the thermal cracking reaction should be 0.5 to 2.5 t×hours-1 ×m-3, relative to the volume V of a shell-and-tube
heat exchanger through which the cracked gas is passed. The pressure drop in the tubular heat exchanger should be 50 to 150 mbars and the
surface/volume ratio should be 60 to 120 m-1
Attachment: United States Patent 4455439.pdf (58kB)
This file has been downloaded 2506 times
Albert Einstein - \"Great ideas often receive violent opposition from mediocre minds.\"
|
|
|
Fashist
Hazard to Self
Posts: 73
Registered: 19-7-2007
Member Is Offline
Mood: Powerful
|
|
Thanks Mr Wizardx
I dont Know Why All Patent About Acetic Anhydrid In http://ep.espacenet.com/ Deleted.!?
Mr Fleaker I want to Use Three Container For Reaction:
First Container Has 30c.
Second Container Has ~5c.
Third Container(Contain Water) 30c
[Edited on 11-12-2007 by Fashist]
|
|
|
not_important
International Hazard
Posts: 3873
Registered: 21-7-2006
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by Fashist
Thanks Mr Wizardx
I dont Know Why All Patent About Acetic Anhydrid In http://ep.espacenet.com/ Deleted.!?
Mr Fleaker I want to Use Three Container For Reaction:
First Container Has 30c.
Second Container Has ~5c.
Third Container(Contain Water) 30c
[Edited on 11-12-2007 by Fashist] |
Because you keep spelling it incorrectly :
| Quote: | RESULT LIST
Approximately 8981 results found in the Worldwide database for:
Acetic Anhydride in the title or abstract
Only the first 500 results are displayed. |
30c ? Chungah? Cullishigay? cups? Congius? Cotyla?
Doesn't sound like the best absorption scheme to me.
|
|
|
Fashist
Hazard to Self
Posts: 73
Registered: 19-7-2007
Member Is Offline
Mood: Powerful
|
|
3lit Erlenmeyer flask is My Container.
C=Centigrade.
Probably http://ep.espacenet.com hasproblem With iran(again Terrorist Reason) Because I cant see Abstract or Original document.(My Search Words Was Acetic
Anhydrid and Anhydrid Acetic)
|
|
|
not_important
International Hazard
Posts: 3873
Registered: 21-7-2006
Member Is Offline
Mood: No Mood
|
|
Anhydride with an 'e' on the end.
|
|
|
Fashist
Hazard to Self
Posts: 73
Registered: 19-7-2007
Member Is Offline
Mood: Powerful
|
|
Ok See these link.
These link have no original or abstract for me.
MANUFACTURE OF ACETIC ANHYDRIDE:
http://v3.espacenet.com/textdoc?DB=EPODOC&IDX=CA702840&a...
MANUFACTURE OF ACETIC ANHYDRIDE:
http://v3.espacenet.com/textdoc?DB=EPODOC&IDX=CA689910&a...
PROCESS FOR THE MANUFACTURE OF ACETIC ANHYDRIDE:
http://v3.espacenet.com/textdoc?DB=EPODOC&IDX=CA487581&a...
MANUFACTURE OF ACETIC ANHYDRIDE:
http://v3.espacenet.com/textdoc?DB=EPODOC&IDX=CA467670&a...
PRODUCTION OF ACETIC ANHYDRIDE:
http://v3.espacenet.com/textdoc?DB=EPODOC&IDX=CA467175&a...
MANUFACTURE OF ACETIC ANHYDRIDE:
http://v3.espacenet.com/textdoc?DB=EPODOC&IDX=CA467174&a...
ACETIC ANHYDRIDE:
http://v3.espacenet.com/textdoc?DB=EPODOC&IDX=CA413976&a...
ACETIC ANHYDRIDE:
http://v3.espacenet.com/textdoc?DB=EPODOC&IDX=CA402110&a...
Enough?
|
|
|
Fashist
Hazard to Self
Posts: 73
Registered: 19-7-2007
Member Is Offline
Mood: Powerful
|
|
Anybody Has Idea for This New Schematic?
Acetone Recycle.
thx
Attachment: Untitled-1.zip (42kB)
This file has been downloaded 898 times
|
|
|
Bromide
Harmless
Posts: 24
Registered: 20-6-2007
Location: Flavor country
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by Fashist
Ok See these link.
These link have no original or abstract for me.
...
Enough? |
It's generally advisable not to ascribe hostile motivations for what can readily be explained by benign factors.
In this case, the links you posted are for patents that are all over 40 years old. Thus the reason why the abstracts and scanned images are
unavailable to you has nothing to do with the fact that you are in Iran--rather, they are unavailable to everyone, because
they have simply never been scanned or typed into the EPO system. Patents of that vintage generally only have their titles, issue dates and
registration numbers available in the public EPO database.
|
|
|
Fashist
Hazard to Self
Posts: 73
Registered: 19-7-2007
Member Is Offline
Mood: Powerful
|
|
Really No Idea?
May This System Work?
I have Problem With U Tube For "Acetone Return" in the Vogel Book.
I Change the Design and I Want to Ask May This Sytem Work Well?
Is Good Idea?
Thanks
|
|
|
not_important
International Hazard
Posts: 3873
Registered: 21-7-2006
Member Is Offline
Mood: No Mood
|
|
It's a clever idea, but it has a major flaw -
remember that at the most you'll only convert about 20% of the acetone per pass through the hot tube. You can increase the amount of acetone
decomposed to higher percentages, but then increasing amounts of the ketene formed decompose - mostly to carbon monoxide and ethylene but also to
small amounts of other stuff that will contaminate the acetic anhydride formed later. In general the experimenters that got the highest overall
yields had relatively small conversions per pass, maybe 10%, and recycled the unconverted acetone.
In your latest idea at least 3/4 of the acetone boiled off is going to be condensing in the upper section. It then runs back towards the hot tube
section, at first boiling before it reaches it through its cooling of the reaction gases. But there will be an increasing amount of acetone up there,
running down and cooling down the upper section of the hot tube. Remember that the acetone doesn't start decomposing until it reaches 500 C or so, so
much of the refluxing acetone is just going to be gargling away in the region between the hot tube and condenser, until there's so much that it
overwhelms the heated section.
What is your intended production rate per day?
|
|
|
Fashist
Hazard to Self
Posts: 73
Registered: 19-7-2007
Member Is Offline
Mood: Powerful
|
|
Mr not important thanks.
You Say Complete True.acetone will not convert to ketene.
But you should accept that in the vogel book(ketene lamp) this is difficult to build U tube for acetone recycle.because the DEPTH of U tube is
DEPENDENT to pressure of acetone(boiling rate and amount),This is problem.
i am building one horizontal system.(one 10 lit flask,1m copper tube,1 meter copper condenser,..) i want to run it and write the diffirent result(i
will test it with aniline)
but i believe the horizontal isnt good system(we must use 10 lit acetone for have 1lit anhydrid or less)i think the vertical system hasnt this problem
but vertical system has U tube problem.what is your suggestion?
for operate my system i want first boil acetone for 5 minutes then i will start the heater because i want no air contain in my tube.i dont want
explosion(is good suggestion?)
do you know the u tube calculate?(i think that need gas pressure physic knowledge)
mr not important,thanks
|
|
|
Fashist
Hazard to Self
Posts: 73
Registered: 19-7-2007
Member Is Offline
Mood: Powerful
|
|
No Answer?
What is Your Idea About Using Small Piece of Copper, Inside Copper Tube In Heater?(More Surface)
I am Waiting...
|
|
|
not_important
International Hazard
Posts: 3873
Registered: 21-7-2006
Member Is Offline
Mood: No Mood
|
|
If you don't have an acetone return, then you must run the system until you've boiled most of the acetone off, cool it down, add back the condensed
acetone plus makeup, bring the boiler up to heat, bring the furnace up to heat, and then start processing the ketene stream. This adds to the amount
of time it takes to make a given amount of product.
I've repeatedly suggested you use an absorption tower as in the PDFs. When run as done in the project PDF, the exist gases from the top of the tower
are acetone vapour and acetone/ketene decomposition products - methane, ethylene, carbon monoxide.
With a return path for the acetone you could get away with a 2 liter boiler, continuously add makeup acetone to the return stream, and still make as
much or more ketene per day as with the open ended large boiler.
Yes, a passive return system will take enough height for the weight of acetone in it to counter the pressure difference between the boiler and
condenser. That's the laws of nature, not easy to get around them. Condensing the acetone gives the liquid acetone for recycling at some height
above the base of the tower, and likely above the boiler. With that arrangement it's fairly simple to design the system so the acetone return
functions properly.
|
|
|
Fashist
Hazard to Self
Posts: 73
Registered: 19-7-2007
Member Is Offline
Mood: Powerful
|
|
there is cheaper SUBSTANCE for testing ketene?
aniline is very expensive here.
|
|
|
Fashist
Hazard to Self
Posts: 73
Registered: 19-7-2007
Member Is Offline
Mood: Powerful
|
|
I just Know Below Method That isnt Easy
|
|
|
not_important
International Hazard
Posts: 3873
Registered: 21-7-2006
Member Is Offline
Mood: No Mood
|
|
The classic reduction of nitrobenzene uses iron or tin. See
Cooley's Cyclopædia of Practical Receipts and Collateral Information by Arnold James Cooley
Experimental Organic Chemistry - James F. Norris
http://www.qo.fcen.uba.ar/Cursos/org2/tpl1.pdf
Electrolytic Preparations: Exercises for Use in the Laboratory by Karl Elbs, Robert Salmon Hutton
http://www.sciencemadness.org/talk/viewthread.php?tid=9799
and numerous other references.
|
|
|
Nicodem
Super Moderator
Posts: 4230
Registered: 28-12-2004
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by Fashist
there is cheaper SUBSTANCE for testing ketene?
aniline is very expensive here. |
Aniline costs about 50 EUR/L. Even if it would be 4 times more expensive where you live and assuming you use 0.5 ml for each measurement, then it
would cost you 0.10 EUR per test.
I bet you paid more to the internet provider for the time you spent posting and reading the replies.
|
|
|
Fashist
Hazard to Self
Posts: 73
Registered: 19-7-2007
Member Is Offline
Mood: Powerful
|
|
My System is Larger than Normal System and I Need to Use 50cc Aniline Per Test.
My Acetone Boiler is 20lit and My Condenser is 2 meter.
I use of internet for sereval Work!.(not just reading)
I have big forum(persian forum about knowledge) and I am active member in Web Programing site and..
[Edited on 19-1-2008 by Fashist]
|
|
|
Nicodem
Super Moderator
Posts: 4230
Registered: 28-12-2004
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by Fashist
My System is Larger than Normal System and I Need to Use 50cc Aniline Per Test. |
This does not make any sense at all. How is the size of your ketene producing system connected with the amount of aniline you use to determine the
concentration of ketene and/or acetanhydride in the product? Why are you using 50 ml of aniline for the testing?
|
|
|
Fashist
Hazard to Self
Posts: 73
Registered: 19-7-2007
Member Is Offline
Mood: Powerful
|
|
Mr Nicodem Soon I will Send Picture of My System.
You Said I Use .5 ml for Testing?
|
|
|
hector2000
Hazard to Others
Posts: 127
Registered: 22-8-2006
Member Is Offline
Mood: Cool
|
|
I am Wonder How Acetyle chloride React With Steel(318) wheras Pure Nitric Acid Cant.! 
Chemistry=Chem+ is+ Try
|
|
|
| Pages:
1
..
10
11
12
13
14 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
