Ok, here is an old thread I had saved, it is quite interesting and gives another idea of KrZ's for a pressure vessel.*Note... This was prior to the soda keg idea!Author Topic: Ketone for lazy people
KrZ
Member posted 01-12-99 01:32 PM
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I'll have to admit I'm pretty slak when it comes to shaking a coke bottle so recently the R&D team here has developed this vessel which has yet to be fully tested.
The stuff we used;
1 ft long 10" diam piece of PVC pipe
2 end caps for PVC pipe
2 x 1/2" male-male brass connector
Tire valve
1/2" brass screw-on endcap
PVC pipe sealer
2 nuts to attach to the male-male connectors
Gasolia Soft-Set
Thread Sealant with Teflon
Tire Pressure Gauge
Tank of Welding O2
1/2" Hi-pressure hose with screw caps (3ft or so)
Elec. tape or whatever
4l beaker, stirbar, stirplate
Take the PVC end-cap and drill 2 1/2" holes and one hole big enough for the tire valve. Put some Gasolia on the male-male connectors and screw them into the 1/2" hole. Screw the nuts onto the connectors on the inside of the PVC caps. install the tire valve and use some gasket sealer to make sure its nice and tight.
Seal the untouched PVC endcap to the pipe with the PVC compound. Place the capped pipe on the stirplate. Slide the beaker inside of the pipe (if its loose put some paper towels in there to stablize it and don't make it a tight squeeze so its hard to get out either). Place your standard list of SRV reactants in the beaker. Drop the stirbar in. Smear the Gasolia on the inside of the other PVC cap. Place the cap on the pipe and pull up and down while twisting so you ensure a good wide seal between the cap and pipe. Make a full loop with the tape around the hole pipe just do be sure (I did it twice to make an X pattern on top/bottom). Screw the hose onto the tank and brass fitting. Attach the tire pressure valve (If you've got a regulator on your O2 tank this isn't necess.). Spray the O2 into it with the other connector open, this way it pushes the atmosp. out. Cap the other male-male connector using Gasolia. Pressurize it on up to 125 psi (thats as high as I took it but who knows). Turn the stirrer on and wait 2 hours or so... You get the picture...
Anyway, the device has been constructed and pressure tested, but no runs yet. I'm assuming you would need to give it 2 hours but it could be less considering the ridiculous amount of O2 we'll be cramming in there. Its certainly alot harder to make than an SRV but once you've got it setup I think it has some minor advantages, I'll provide an update on how it goes in action as soon as I can.
...and here is how it proceeded.KrZ
Member posted 01-14-99 11:18 AM
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I'm going to redistill to make sure;
In the beaker went;
3.5 g PdCl2, 45g CuCl, 295 g Safrole, 875 ml DMF.
Pressurized it up to 120psi, let it stir with a heavy ass vortex for about 2 hours(so hard a large portion of the bottom of the beaker was exposed and @#%$ was way up on the sides). Extraction as usual. Distilled off the DCM and everything else coming over before 142C, then came a fraction at 148C weighed it at 8.6g, and another one at 152C weighed it at 285g. First fraction was yellowish and had an odor, second fraction had no odor and was yellow-light-greenish with no smell. Remember this vacuum pump is retarded, it pulls safrole over at 127. I also tried using the silicone glass-joint stuff to make a seal and it didn't hold as well as the gasolia (I could hear it leaking). The room it was done in was about 50F.
...and then...KrZ
Member posted 01-17-99 10:57 AM
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I went to a local welding supply place, they had regulators that went up to 100, 125, 150 and various other levels (with increasing cost the higher it was rated for) the one I got goes up to 125, as you might have guessed. It was a pain in the ass finding an adaptor to get it to connect to the 300psi presssure hose I bought, it was a 5/16" size regulator and the hose was 3/8", apparently a very uncommon combination cuz I had to go 5/16->1/2->3/8 with brass adaptors to hook it up. I'm perfectly content at 125,
I didn't wash the filter cake when drying,(What filter cake?..placebo) left ml's of oil here and there in beakers, and knocked over a 250ml beaker with some oil in it, so I believe actual yields were very high. The PVC I bought only came in a 10ft piece at a time (got funny looks from the counter guy when I wanted only 1 ft) so I've got a big piece sitting in my backyard. I'm going to get an ABS pipe before I do it again as it seems Beagle was quite right (after reading up on it). Trying to think of a way to fit a big rubber o-ring around the inside of the pipe and designing some latches for quick snap-on loading ;-) I'm pretty satisfied with all yields but, I want to get something real nice and take a pic. of it and upload it for you guys to see.
Amination is currently proceding under nitrogen using 300g of MeAm in just enough MeOH to dissolve it (you need to dissolve the MeAm in methanol first and it takes an hour or so of careful checking addn. to get it perfectly saturated, which is important!). You don't need to waste a kg!! Just wait longer, check the pH and adjust accordingly, use heavy ass stirring and you'll get the same yields!!
For removable endcap.TheCat
Member posted 01-20-99 10:16 PM
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KrZ, one more thing. Have you had anyone more dreams at high preasure? If you have how were the yeilds?
Also I was a thinking. You want a nicer looking presure vessel? Go to the plumbing store and ask for a "clean-out" for you 10" ABS or PVC pipe. What a clean-out is is a section of pipe that looks kinda like an end-to-end pipe coupler with a big ass threaded plug in one side (if you go ask for one you will know what I'm talking about). What you would do is put the regular end cap on one end then attach the clean-out to the other end and there you have it. A preasure vessel with a screw on cap.
A good point by Semtex...Semtex Enigma
Member posted 01-22-99 08:59 PM
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Small correction/note: The purpose of a regulator in situation which you are describing is not correct. You see when a regulator(say 125psi) is hooked up to the O2 tank, all it is doing is regulating the flow of gas through the tube from the regulator at a maximum pressure of 125psi. It does not control the pressure in the vessel, only how fast the gas enters it. To get an accurate reading of the pressure inside the pipe one would have to equip the vessel with a gauge.
I once suggested a modified version of Piglet's proposed bubbler for the wacker. You see I think that bubbling under atmospheric pressure would be uneffective, however I have reason to belive that it would indeed work under increased pressure. I will try to write up an outline for those in the position to dream of such things. If anyone is interested please let me know...
Results...KrZ
Member posted 01-23-99 12:03 AM
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It was about 80%, theres still some more rexytal. in the IPA now so I don't know exactly yet. I just waited a little longer, was very careful dissolving my MeAm to assure saturation, and I filled it with nitrogn and capped w. a ballon each time, I also checked and adjusted the pH with a digital meter every 6h. Other than that its all been said before...
I told the guy at the welding place I would be injecting N2 into soil for an Ag. Exp. involving ag. engineering; oxygen/nitrogenation injection cost analysis for farms, etc. he believed every word, he said I'd need a tank and regulator, then he produced a brass piece with two pressure gages and another steel piece that fit into it with a big plastic knob and another gag, he said just hook the flow regulator to the tank and the pres. regulator up to it. Thats what you get for welding standard set up right? If the flow reg. was just on there I suppose all 1000osi or whatever that tank is at would come across, boooom! I've been looking at these stainless stell compressed gas tanks MSC direct has, 4.7 gallon capacity one for ex., some welding to attach a mechanical stirrer would be needed for anything bigger but I think a big stirbar and some fine tuning of the plate to get max spin would do it for this size. Could form alot of ketone that way....
Some wise words from psychokitty...psychokitty
posted 02-22-99 08:58 AM
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As for KrZ's set-up, I have a little bit of information to offer.
I spoke recently to a machinist who know something about pressurized canisters and he told me that PVC pipe fittings are pretty resistant to corrosion and could possibly hold up to using the reactants directly in the container itself. But since one can't be sure, it probably would be best to conduct solvent tests.
The pressure and temperature ratings of PVC can be found printed on the sides of the pipe so that should make it easier to determine how much of a beating it can stand.
I also asked about the danger of explosion and he said that more than likely, there would be no danger as long as the temperature and pressure of the reaction did not exceed the limitations of the pipe's design. HOWEVER, if the pipe was dropped -- not even from very high up -- it could very likely break causing the undesired aforementioned explosion. And BTW, it doesn't matter if it is ABS or PVC or whatever as the impact from the released air alone could cause serious injury.
As for the easy access issue, the ends of the piping could be threaded, or installed with a threading adapter.
KrZ: I must admit that I am confused as to why you use so much O2 pressure when you could easily get away with less. We all know that 30 pounds is effective at transforming the alkene to the ketone in alcohol solvent in 2 hours using just regular air! So why not simply start with a little over 30 pounds and once the oxygen gets used up and the pressure goes down (to just a little under thirty pounds), simply inject more oxygen until 30 pounds is reached again?
Just a thought.
--Psychokitty
What type of plastic pipe should I get?dpHarma
Member posted 02-22-99 08:24 PM
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the pipe of choice is HDPE high density polyethylene.
a great deal of study has gone into plastic pipes used for launching pyrotechnic aerial shells. when a shell explodes in it's launching 'mortar', the total combustible material is comsumed at once (or nearly) and the forces are confined in the tube.
PVC and ABS shatter into many small sharp fragments. HDPE tends to deform first and producess much less shrapnel.
dpHarma
Hope this helps a bit?
I like it!
Wanna do the rumpy pump?