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04-11-00 23:56
No 107796
(Rated as: good read)
[Image] [Image] the Hive BB
[Image][Image] Methods Discourse
[Image][Image] Practical palladium salt recovery (Page 1)
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Author Topic: Practical palladium salt recovery
rev drone [Image] posted 07-17-1999 02:46 PM I've been giving this problem A LOT of attention as of Thus far, the most promising method looks like a cute I have ref's, and I'm still pouring through all the So what do people think? Despite my best efforts, I Looking forward to your input, ------------------ rev drone [Image] posted 07-17-1999 02:52 PM ------------------ Semtex [Image] posted 07-17-1999 06:29 PM Good to see you again, can't wait for the next sermon... rev drone [Image] posted 07-17-1999 06:57 PM Thanks SE; glad to be back. Yeah, it was kinda harsh at Anyways, 70% is pretty good, but I'm shooting for 99% if Say, what about crashing it out by adding some highly Thanks for sharing; anybody else out there want to join ------------------ ymir [Image] posted 07-17-1999 08:12 PM Semtex [Image] posted 07-17-1999 08:22 PM Semtex [Image] posted 07-17-1999 08:26 PM ymir [Image] posted 07-18-1999 05:02 AM ymir [Image] posted 07-18-1999 08:59 AM LaBTop [Image] posted 07-18-1999 09:41 AM ------------------ LaBTop [Image] posted 07-18-1999 09:46 AM ------------------ LaBTop [Image] posted 07-18-1999 09:54 AM ------------------ r2d3 [Image] posted 07-18-1999 11:58 AM Semtex [Image] posted 07-18-1999 02:02 PM LaBTop [Image] posted 07-19-1999 08:40 AM ------------------ spitball [Image] posted 07-20-1999 04:30 AM 1) Simple filtration a)A Centrifuge (LabTOp) b)Resin filled chromatographic pressure column with c)Celite (aka Filter Aid, or Dimotaceous Earth) to cut d)A piston/cylinder thingy with a paperfilter at the 2) Electrolytic methods a)cementation or reductive precipitation (Ymir) b)electrolytic precipitation (Ymir) 3) Solvent Extraction (Ymir,myself) (no details mentioned) 4)Chemical reduction a)sodium borohydride to recover palladium salts from an b)1:1 PdCl2 / 37% formaldehyde, and 30% NaOH added to 5)Chelation/titration a)basify, then filter out Pd(OH)2 ppt. (rev drone) b)chelate with NH4Cl to precipitate Pd(NH4)2Cl4, which c)chelate with dimethylglyoxime, filter out ppt. (rev Thus far, here are my thoughts on the suggested 1) Merely filtering out the precipitated PdCl2 salt is 2) There are three main drawbacks here. First, we still 3) Now this would be nice, if only there was somebody 4) There is a BIG problm with one of these methods: using 5)Lastly, there is the precipitation using chelating So, we have a good list with some healthy variety in it. ------------------ spitball [Image] posted 07-20-1999 10:08 AM -spitball- LaBTop [Image] posted 07-20-1999 10:14 AM ------------------ spitball [Image] posted 07-20-1999 10:26 AM -spit'fuckin'ball Xeolite [Image] posted 07-21-1999 04:30 AM I'm your pusherman?! PUSHERMAN? HAHAHAHA LaBTop [Image] posted 07-21-1999 10:38 AM ------------------ rev drone [Image] posted 07-22-1999 11:19 AM I don't think a centrifuge is practical. like I said, my To tell you the truth, my experience is rather limited ------------------ prickleberry [Image] posted 07-22-1999 01:18 PM equarius [Image] posted 07-22-1999 02:45 PM The best method must convert it to PdCl2 and make it LaBTop [Image] posted 07-22-1999 03:46 PM The PMK will dissolve in the MeOH, thus becoming overall ------------------ LaBTop [Image] posted 07-22-1999 04:02 PM ------------------ rev drone [Image] posted 07-23-1999 02:58 PM Just to clarify what system we're looking at, let's take
Hive Bee
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I thought I'd open this thread, since despite the
popularity of the Wacker oxidation, little discussion has
gone into practical, eficient methods of recovering that
oh-so-expenisve catalyst from the reaction.
late, trying to find an easy way to get back clean, pure
PdCl2 (or its equivalent) without too much mess, too much
heat, too much disgusting organic tar impurities, etc.
cheating trick, used by inorganic chemists to purify
precious metals. By adding ammonium chloride, followed by
excess ammonium and gently heating, the ammonia will
chelate with the palladium salt, forming Pd(NH3)2Cl2,
which precipitates out nicely (this relies on the fact
that palladium, despite its formal +2 charge, is
4-coordinating and likes the nitrogen's lone pairs;
d-block chemistry is wierd, ain't it?) Another even
quicker, cleaner method might be with dimethylgyoxime (
H3C-C(=NOH)-C(=NOH)-CH3 ), which apparently chelates even
better. The precipated palladium complex is extremely
pure, filters well, and is very insoluble in damn near
everthing. Apparently, these complexes can be converted
back into our belove catalysts with the aide of hot Hcl
solution.
literature, but I thought this little nugget might get
people thinking, and thus perhaps help 'catalyze' the
developement process of this technique. The more people
working on this, the better. Input is always appreciated.
couldn't find too many hot procedures our there in the
clandestine literature, but that doesn't mean its not
there. If anyone has an obsucre nugget of chemical
technology that they'd like to share that will blow my
suggestions out of the water, please do so.
-the good reverend drone
Hive Bee
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Of course, I mean "chelating", not "cheating". Also I
forgot to mention methods involving simply precipitating
Pd(OH)2 by adding conc. base, though this doesn't strike
me as an easy-to-filter thing to do. Another thing to
consider is using ETDA as a ligand; not sure how it would
work, but I'm sure something could be arranged.
-the good reverend drone
Enigma
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Drone!!! Nice to see you back up and about, that Spitball
PiMP didn't treat you too badly did he? I had a
discussion some time ago with some people about this very
subject(Pd recovery) and came to the conclusion that in
an air or O2 powered wacker one could usually recover a
good 70%+ of the PdCl2 by repeatedly filtering the rxn
mixture at the end of the rxn. It is recovered as PdCl2
so there is no need to convert it back. Fine filter paper
and LOTS of filtrations give the best results from what
I've heard. However I think most people are using the
benzo wacker now, would your recovery method work with it
as well???
[Image]
Hive Bee
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SE,
Spitball's little "Economic Empowerment Camp", but I'm
still alive. Remeber this: if you ever consider
responding to one of those sleazy ads like "Make Money
FAST, FAST, FAST", or "Lose weight...And get paid while
doing it!", remember there's a good chance that Spitball
is the one behind it, and you too might end up sewing
together fake afro's (or worse yet, put on "mule detail"
-- ouch!!)
possible. If this were done on a large scale (which is
concievbly could), then filtering large volumes of
solution for semi-suspended microparticles doesn't sound
fun. What was the URL for this discussion? Definately,
the method that you suggested has a lot of merit,
considering the simplicity.
soluble chloride salt, thus precipitating it due to the
effect of competing ions? Perhaps saturating the solution
with ammonium choride? It might precipitate the copper
salt as well, but who knows? Maybe if it were saturated
with CuCl2, the PdCl2 would simply crash out, and could
be washed clean with something? I dunno. just a thought.
I think I may have the solubility thing backwards, so
please correct me if I'm wrong.
in the discussion?
-the good reverend drone
Hive Bee
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Doesn't Brauer's recommend the use of ammonium chloride
for this recovery? It would seem that this particular bit
of recycling would be of immense use to many members of
the Hive. A patent was mentioned (US patent #5,304,233)
by r2d3 awhile ago. This bee would be very interested in
any information in this matter.
Enigma
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Giving the URL would bee difficult as this discussion
took place thru email. I'm not sure if the method you
suggest would work because I am not into the chem-speak
as deep as you are. It doesn't seem all that difficult
and it means one less thing to keep buying, with LaBTop's
method(s) to madness(25KG!!!) that's a LOT of PdCl2...
[Image]
Enigma
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Oh yeah, Drone before I forget, go get yourself an
account at http://www.hushmail.com , on the fly encryption, can
be used WITH PGP to add another layer of security...
[Image]
Hive Bee
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Semtex: Did any of the bees try using Celite (aka Filter
Aid, or Dimotaceous Earth) to cut down on the
filtrations?
Hive Bee
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Other methods that may bear fruit, depending on equipment
availability and skills, would be cementation or
reductive precipitation, and electrolytic precipitation.
An iron cathode is used to cement copper, this may
provide a means of seperation of copper from palladium.
Electrowinning is a more selective technique than
cementation, it has been used to seperate copper from
other metals. By carefully controlling the cell
potential, a selevtive seperation is possible. This is
the method of choice for refining copper. The copper
serves as the soluble anode. Another technique of
possible use is solvent extraction. Several extractions
are usually required. Sulfuric acid is most often used
for sludge extraction. A few good references that should
be looked at are: Metal Recovery from Industrial Waste,
by C. S. Brooks (1991); Solvent Extraction, Part II, G.
M. Ritcey and A. W. Ashbrook (1984) and Industrial
Electrochemistry, C. L. Mantell (1950).
PimpBee
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A Centrifuge. LT/
EMOTIONSwill always beFREE!
PimpBee
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A Resin filled chromatographic pressure column with
tubing pump. LT/
PS: 25 kg we used to call a sample run...
EMOTIONSwill always beFREE!
PimpBee
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A piston/cylinder thingy with a paperfilter at the
bottom. Press all the fluids through, burn the filter +
rest at 800 C in a little oven. Hope PdCl2 stays behind.
Or lower temp. LT/
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Hive Bee
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The patent I mentioned, uses sodium borohydride to
recover palladium salts from an acidic solution. Check it
out on the IBM patent server.
Enigma
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LaBTop: Could I be the "taste tester" for your "sample
run"?!? [Image]
PimpBee
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What about 1:1 PdCl2 / 37% formaldehyde, and 30% NaOH
added to slightly alkaline, heat to 80 C, stirr 10 min,
let catalyst settle down.
Decant the supernatant solution, replace by water and
resuspend the catalyst.
Wash the catalyst by decantation 8-10 times with water
and then collect it on a medium-porosity sintered glass
funnel, wash with five 25 ml portions of water and suck
as dry as possible.
Dry the funnel and contents at 80 C , powder the catalyst
and store in a tightly stoppered bottle.
Catalysts reduced with formaldehyde contain no absorbed
hydrogen and are less pyrophoric. (If you used them in a
hydrogynator).
Why not use PdCl2 on carbon? Can be stored indefinitely.
The palladium salt is reduced to the finely metal as
required:
PdCl2 + H2 --> Pd + 2HCl
or as finely-devided metal deposited upon activated
carbon (5 or 10 % Pd):
Na2PdCl4 + HCHO + 3NaOH --> Pd + HCOONa + 4NaCl + 2H2O .
I mixed a few methods here, see what you can do with it.
Have more if you want. Am sleepy.
LT/
EMOTIONSwill always beFREE!
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Let me sum up suggestions thus far into 5 separate
categories to aid in our discussion.
tubing pump [i.e. a preparative-scale HPLC
machine](LabTOp)
down on the filtrations (Ymir)
bottom. (LabTop)
acidic solution (r2d3)
slightly alkaline, heat to 80 C, stirr 10 min, let
catalyst settle down. [etc.] (LabTop)
would be worked back into PdCl2 (rev drone)
drone)
procedures:
all well and good, but the yield of this recovery method
doesn't sound too promising. Simple? Yes, but the fact
only aout 70% or so is recovered makes me hesitant. This
is definately the way to go wen you don't feel like
wasting time, and maybe will turn out to be the best way
overall -- who knows?
need to remember the fact that some very precious ketone
is floating in there, and if one isn't conscius of the
conditions, organic compounds like delicate ketones in an
electrolytic cell can get ugly FAST. The next big
drawback is equipment -- most organic chem labs aren't
equiped with electrolytic equipment, neither is the
average home, and nor are most organic chemists
well-aquainted with the operation of said equipment. But
hey, if its a clean, easy way, and you have some
practical literature pertaining to it, please bring it
on.
with literature on this. Just one or two solid ref's of
Pd recovery using this would be of immense help. I
thought about this one myself, but haven't found anything
in the literature yet. Attractive, but really not too
much to go by here.
NaBH4 will reduce your ketone too! The formaldehyde
reduction doesn't sound too aweful, but again, the
catalyst would need to be oxidized back to Pd2+ at the
end.
ligands. Cheap, effective, simple -- or so it would seem.
I still haven't found a good example of recovering PdCL2
from the tetrachloro complex, though the glyoxime
apparently is quicky made back into PdCl2 by treatment
with aq. HCl (don't quote me on that; all I remember
right now is that its simple.) If a straight forward
means of converting Pd(NH4)Cl2 to PdCl2 is available,
this method really looks slick. Otherwise, the glyoxime
precipitates the Pd2+ species very quickly.
You can see my preference shining though, but that's just
me. This is a good discussion -- let's keep it going.
"I'm your Mama, I'm your Daddy
I'm that nigga in the alley
I'm your doctor, when in need
Want some Toast? Have some weed
You know me, I'm your friend
Your main boy, thick and thin
I'm your Pusherman"
Pimp Master
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Uhhh, Just FYI, that above post was Rev. Drone, using MY
computer and not stopping the look at the fact that MY
name was posting. Fucking how DARE he disgrace my good
name with this garbage!
The signature is pretty funny though after drone's name!
hahaha..
PimpBee
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I think the centrifuge would work the fastest, but I need
some explanation into what mix of chems you are left with
at the end of the process, then I can give you a
procedure for that.
Btw, has rev drone found your password, boss?
Your writing suddenly looks identicall and nearly no
typos....not one fuck in it... amazing! [Image] LT/
EMOTIONSwill always beFREE!
Pimp Master
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Yeah, fuck.
Hive Bee
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I saw one typo right off the bat:
PimpBee
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rev drone, a neat trick could be to use a layer of DCM
,d=1,2 in the centrifuge and pipette your PdCl2 +
solution slurry carefully on top of it. The PdCl2 (heavy)
can enter the DCM, all other fluid products will stay on
top of it after spinning.
To make your own centrifuge is first year mechanics
stuff, easy as chickenshit. [Image] LT/
EMOTIONSwill always beFREE!
Hive Bee
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LabTop,
pilot plant-scale centrifuge is in the shop right now.
[Image] I sent it in just to get a tune-up, but now they
told me it needed a new transmission and a lot of work on
the engine block, and wouldn't say when they'd be done.
The lousy bastards. [Image] I'm sure most other bees are
in the same situation.
with centrifuges, so you'll have to explain to me why the
ketone, which is also fairly dense as well as
hydrophobic, won't follow the PdCl2 into the DCM layer.
-the good reverend drone
Hive Bee
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Welcome back sir Reverend Drone, the Hive is a much
better place with you around. [Image] Hope you'll give us
a little warning next time you reply to one of those "get
rich quick adverts". We were all worried sick about you.
[Image] Anyway, my knowlege is limited in this area, but
a few methods I have seen posted around here and in books
are as follows.
* Hydrazine is used to reduce the Pd back to the metal,
then filter out.
* A ball of steel wool is tossed in the reaction (or
another more active metal) the Pd gets reduced back to
the metal, and filters out. HCl acid may be needed to get
things moving.
*The whole reaction mix is filtered through an alumina
column, with the Pd getting stuck in it.
These are all un-tested by prickleberry....so they might
not work, prickleberry is just keeping the ideas
rolling.....
Prickleberry out.. [Image]
Hive Bee
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Simple filtration recovery is not practical. I mean you
can do it, and I've the dirty filtration papers to prove
it, only a fraction is removed (~50%). If any bee has
ever recovered Pd from multiple wackers and converted it
back to PdCl2 in any amount, then used it again with
success, then they should speak up. Besides for air or O2
wackers I'd rather just say screw that little bit of Pd
and move directly on to purification.
insoluble so it could then easilly be filtered out,
without wrecking our fragile ketone.
PimpBee
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I still do'nt know what slurry we talk about(what's in
it?) and what the next step should be, but let's assume
you want to aminate with NaBH4 the MDP2P.
I would then dissolve the sludge in a minimal amount of
MeOH to get a solution with a lower density then DCM, but
with the Pd salt as the only heavier part in it.
Then I liberate the front wheel of my little sisters bike
in the name of science and we gonna make a nice little
centrifuge from that. Bet she will like that too!
Fastest way is to weld a small, thick piece of pipe over
the axis of the wheel halfway and the other half fits
over the axis of a nonsparking induction elektro motor(
we do'nt want to burn the little girl while she's
watching our caprioles, aint it?)
Now we mount this piece of ingenuiety(?) on a firm
standing table.
Next we make 2,4,6,8 etc plastic bottles with each 2
holes in the open sides at the top, oppossite of each
other. Then we make 4,8,12,16 exactly the same length and
weight steel wire hooks.
We hang the bottles opposite of each other at the wheel
with them hooks.
VOIL- : Your homemade kgscale centrifuge ! Full power on
the motor and test first with EQUAL amounts of water in
the bottles. Cola cans will do also, all the same weight
and only a small opening......
less dense, and your Clean PdCL2 will be left in the DCM.
(I hope...)You can proceed with the MeOH/PMK solution to
the next step! [Image] LT/
EMOTIONSwill always beFREE!
PimpBee
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Greetings from my little sister Guinevievre McGuiver, and
you can make a bid for her frontwheel over at Ebay
Auctions. (Btw, she's only 51, but still very playfull!).
She's particualary fond of Chemical Detonations, the
little Schmuck. Red hair, but I forgot if its her natural
or if its chemically induced...Likes to play in the Lab,
so..... LT/
EMOTIONSwill always beFREE!
Hive Bee
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LabTop,
a typical situation. Actually, I already posted it, but
let's lo
(Member)
04-12-00 00:05
No 107797
rev drone [Image] posted 07-23-1999 02:58 PM
Hive Bee
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LabTop,
Just to clarify what system we're looking at, let's take
a typical situation. Actually, I already posted it, but
let's look at it again, shall we? The SRV/KRV variation
of the Wacker.
At the end, in the solutioner we have:
EtOH
ketone
isomerized starting material
red tarry gunk
CuCl2
PdCl2
There is also some PdCl2 precipitated out of the solution
in the vessel. This is the situation we're looking at.
At this point, there is no "sludge", per se. The solution
is already less dense than DCM, and again the solvent
here is EtOH, which is miscible with DCM. "the Pd salt as
the only heavier part in it." Don't forget that the
densities of CuCl2, ketone, and isomerized starting
material are *all* denser than MeOH, in fact they are all
denser than H2O, and in the case of the inorganic
compounds, denser than DCM.
I really think precpitation is sounding better and
better. Dimethylgyoxime chelates the Pd2+ species, and
crashes out. This is filtered, and the filtrate added to
a ammonium hydroxide solution, boil. Now add HCl, and you
will precipitate out Pd(NH3)2Cl2, or palladium yellow.
This is kinda where it get's stuck...
------------------
-the good reverend drone
LaBTop [Image] posted 07-24-1999 06:16 AM ------------------ LaBTop [Image] posted 07-24-1999 11:42 AM ------------------ rev drone [Image] posted 07-24-1999 12:30 PM I think we're having a communication problem. Let me * ketone (the actual final product of the reaction) Everything I just lised is DISSOLVED in EtOH; they're all Regarding all this "decanting", I think you must mean quote: The red tarry gunk *CANNOT* be simply separated off by Now I have to admit I'm skeptical. I have a hard time Now what I meant of course was a system THEORETICALLY There are numerous chelating procedures in the ------------------ rev drone [Image] posted 07-24-1999 12:40 PM ------------------ Osmium [Image] posted 07-26-1999 05:05 AM LaBTop [Image] posted 07-26-1999 11:58 AM ------------------ LaBTop [Image] posted 07-26-1999 12:00 PM ------------------ LaBTop [Image] posted 07-26-1999 12:01 PM ------------------ rev drone [Image] posted 07-26-1999 01:49 PM Sounds like your little sister would DEFINATELY not want Extracting with hexanes would nice, but I'm not so sure As for the catalyst purification, yes heating palladium As I said before, Chelating Pd to extract it is still 1. Precipitate Pd out of the solution with PdDMG Now those extra amine ligands are a pain-in-the-ass, as Here's a question: if you carefully heated palladium The problem is, there are tons of ref's on recovering Pd Incidentally, in case anyone wanted to know, as everyone Anyways, that's all I have to say 'bout that for now. Take care, ------------------ LaBTop [Image] posted 07-26-1999 06:42 PM And you still can liberate the pure Pd and use that in But I have the same problem: if it looks impossible, ------------------ rev drone [Image] posted 07-26-1999 07:18 PM So, with this nugget of information, we know to add H2O, For small-scale Wacker oxidations, it really doesn't pay Which reminds me of something. You seem to know a thing ------------------ LaBTop [Image] posted 07-26-1999 08:42 PM ------------------ equarius [Image] posted 07-27-1999 09:52 PM This is pretty tricky because it would have to be Obviuosly I don't have the chem knowledge, or even the Feasable?? jimwig [Image] posted 07-28-1999 04:19 PM rev drone [Image] posted 07-31-1999 04:53 PM The problem is that there are still other byproducts in ------------------ ymir [Image] posted 07-31-1999 06:44 PM rev drone [Image] posted 07-31-1999 07:22 PM ------------------ ymir [Image] posted 07-31-1999 07:43 PM ymir [Image] posted 07-31-1999 09:13 PM rev drone [Image] posted 07-31-1999 09:22 PM Still though, why the interest in centrifuges over the ------------------ Osmium [Image] posted 08-02-1999 04:06 AM
PimpBee
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Are these Pd salts perhaps attrackted by a magnet?
If not, why not decant the mix,red tarry gunk GONE. Then
dissolve all the decants in DCM, and centrifuge.
Now you decant again, and you have a LAYERED mix of 2
solids: CuCl2 and PdCl2.
That looks simple to me to seperate...
The decanted fluids is another story, to be continued.
Eeh, do'nt forget I do'nt know the SRV/KRV, give me a url
please. [Image] LT/
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PimpBee
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Some new info on use of hexane to get rid of the tar from
MethylMan:
http://hive.lycaeum.org/ubb_board/Forum1
[Image] LT/
EMOTIONSwill always beFREE!
Hive Bee
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Pd salts aren't ferromagnetic, but that certainly is good
thinking. How would you remove the red tarry gunk? To
clarify myself, the gunk is dissolved in the EtOH.
re-state what the situation is. At the end of the
reaction, one is left with an ethanolic solution of the
following:
* isomerized starting material (a byproduct of the
reaction)
* red tarry gunk (a polymerized byproduct, fairly soluble
in organic solvents)
* CuCl2 (the cocatalyst)
* PdCl2 (the catalyst)
in there, floating around together in solution. There is
a small amount of precipitated PdCl2. This is easily
enough filtered out, but it does not represent the bulk
of PdCl2 present; most of that is still dissolved in
EtOH.
something else.
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decant \De*cant"\, v. t. [imp. & p. p.
Decanted; p. pr. & vb. n. Decanting.] [F.
d['e]canter (cf. It. decantare), prop., to pour
off from the edge of a vessel; pref. d['e]-(L.
de) + OF. cant (It. canto) edge, border, end.
See Cant an edge.] To pour off gently, as
liquor, so as not to disturb the sediment; or
to pour from one vessel into another; as, to
decant wine.
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decantation. As for your "Decants", I can only assume you
mean either 1)the sendiments left over after pouring, 2)
the liquid that was poured off. Either way, I don't
understand what you're doing.
believing that a home-made centrifuge, using a bicycle
tire, is going to be powerful enough to cause the two
inorganic salts in question to precipitate out in even
layers. Typical commercial centrifuges run in the range
of 10,000 to 100,000 rpm. If you're doing this on a small
scale, you're still talking about at least a kilogram of
solution being spun around at rather high velocities. If
you're taking about an industrial-scale batch (like one
of your 25 kg "sample batches"), you're talking about
using a centrifuge rotating possibly HUNDREDS of liters
of solution at 10,000 rpm. Your little sister's bicycle
wheel PROBOBLY won't work here. Then again, I guess I've
never seen what kind of bicycle your sister rides.
similar to the SRV/KRV procedure, which can be found at
http://rhodium.lycaeum.org/chemistry/mdp
practical oxidation of safrole is a nice system to
analyze, but all of this is of course only academic
musings.
literature, though the one that stands out the most is
with dimethylglyoxime. The question is, once you've
formed a nicely-cheltated metal cmplex, how do you remove
the ligands to return to PdCl2?
-the good reverend drone
Hive Bee
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I guess what I'm saying is, its very easy to recover
palladium using DMG, ETDA, 2,4-pentadione, etc., but then
one is left with an insoluble palladium chelate, like
PdDMG, but not PdCl2. MY question is, would treating the
chelated precipitate with HCl lead to PdCl2 again? If its
that easy, we 're set.
-the good reverend drone
PimpBee
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IMHO it would be best to quench the SRV with water,
extract the organics with hexane (which hopefully does
not dissolve anything inorganic), and collect the aq.
solution. Once you have enough of it (like several liters
containing 20g Pd or so), you can start your recycling.
Reducing agent which doesn't reduce the copper, followed
by some aqua regia or HCl/Cl2 or HBr/Br2 to make PdCl2
again. Or any other of the procedures mentioned above.
PimpBee
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I support the advise of Osmium, plus:
Palladium can be recovered by heating the spent catalyst
to redness in order to remove organic impurities.
The palladium is then dissolved out with aqua regia and
the solution evaporated; the residue is dissolved in hot
water and hydrochloric acid to form palladium chloride.
Vogel,first edition, 1948, page 670, Section IV,120,the
Rosenmund reduction of acid chlorides.
That's a simple answer to a simple question.
BTW, my sister rides a Norton Commander, a collectors
item.She's a wild woman, looks abit like, eeeh, Cher, but
then red. [Image] LT/
EMOTIONSwill always beFREE!
PimpBee
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I support the advise of Osmium, plus:
Palladium can be recovered by heating the spent catalyst
to redness in order to remove organic impurities.
The palladium is then dissolved out with aqua regia and
the solution evaporated; the residue is dissolved in hot
water and hydrochloric acid to form palladium chloride.
Vogel,first edition, 1948, page 670, Section IV,120,the
Rosenmund reduction of acid chlorides.
That's a simple answer to a simple question.
BTW, my sister rides a Norton Commander, a collectors
item.She's a wild woman, looks a bit like, eeeh, Cher,
but then red. [Image] LT/
PS: why do I think your not satisfied with this.....?
EMOTIONSwill always beFREE!
PimpBee
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I support the advise of Osmium, plus:
Palladium can be recovered by heating the spent catalyst
to redness in order to remove organic impurities.
The palladium is then dissolved out with aqua regia and
the solution evaporated; the residue is dissolved in hot
water and hydrochloric acid to form palladium chloride.
Vogel,first edition, 1948, page 670, Section IV,120,the
Rosenmund reduction of acid chlorides.
That's a simple answer to a simple question.
BTW, my sister rides a Norton Commander, a collectors
item.She's a wild woman, looks a bit like, eeeh, Cher,
but then red. [Image] LT/
EMOTIONSwill always beFREE!
Hive Bee
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LabTop,
that to happen to her bike. [Image] Well, I guess you
think I'm not satisfied for several reasons: 1) Because
palladium chloride has a surprising tendancy to be
readily soluble in a lot of non-polar solvents, and so a
simple extraction like that is questionable (many Pd
complexes favor non-polar solvents; a fact that is
utilized in cases of Pd recovery where large amouns of
organic products aren't involved), 2) Because the
purification of palladium by reducing and regenerating
PdCl2 sounds like more work than it has to be 3) because
I can be a pernicious little jerk when it comes to this
stuff (I can't rest until I've examined something like
this backwards and forwards and from every possible
angle.)
it'll work. Oh yes, hexanes will extract the ketone, but
I'm not convinced that it wouldn't leave the palladium
salts alone. DCM, a rather non-polar solvent, when used
in this fashion, does an EXCELLENT job extracting both
product AND catalyst together. Now hexanes are definately
more non-polar, and this may do the trick -- I guess
someone will have to try it out (if I hear any rumors in
the near future, I'll keep y'all posted.) I'm definately
not ruling it out, mind you; this may be the way to go.
I'm just pointing out the fact this may not be the
solution.
to redness will destroy impurities, but I'd prefer to
avoid having to go back to the metallic form and
regenerating PdCl2 with aqua regia and HCl. Of course, if
all else fails, this would work, and it might not be so
bad if combined with the chelation step ( PdDMG is
precipitated, then reduced by roasting or by NaBH4 in
chloroform to the metallic form, yada, yada, yada.)
pretty nice looking, though I have to admit I'm still not
100% certain as to the best means of making it back into
PdCl2. Thus far, I propose:
2. Dissolve PdDMG in excess NH4OH sol., boil, then add
HCl to crash out Pd species as easily-filtered palladium
yellow, Pd(NH3)Cl2
they are bonding to the palladium right where our
catalyst friend does its magical thing, but this may not
be too much of a problem. Those amines are very
loosely-bonded ligands.
yellow, could it be selectively decomposed to PdCl2?
Rather than roast it all the way to Pd(0), could one just
heat it up enough to liberate the two ammonia
equivalents? According to the CRC, palladium yellow
decomposes at a fairly low temperature; is the product
from decomposition the stuff we want?
as a metal, but few on keeping it as a salt. The result:
ton's of descriptions of recovering catalytically useless
salts and roasting them into Pd sponge.
already knows, Pd is oxidized by aqua regia, and PdCL2 is
obtainable that way, as well as by Cl2 gas at red heat,
but Pd can also be oxidized by nitric acid, yielding the
nitrate, Pd(NO3)2. This, when heated in H2O, decomposes
to yield Pd(OH)2 (a very active hydrogenation catalyst
indeed), which could be acidified to yield PdCl2.
Please, if anyone out there knows the answer to my
question about the decomposition of Pd(NH3)2Cl2, pleeeez
say so.
-the good reverend drone
PimpBee
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Some ECONOMIC ruling of thumb:
When you have to consider the amount of labour, risk and
chemicals involved, would'nt it be a bit wiser to forget
the damned stuff, bill the EVENTUAL clients with a raise
in price, and buy from that your next batch of PdCl2 ? So
just filter it out?
numerous other (pressurized)hydrogenation
techniques...easier by the way...more yield by the way...
that's the point when it gets really interesting, there's
allways a way, but at what costs and risks? [Image] LT/
EMOTIONSwill always beFREE!
Hive Bee
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I did a search, and found that, yes indeed in
http://hive.lycaeum.org/ubb_board/Forum4
everyman mentioned that extracting the ketone w/
petroleum ether was the preferred method, since it
extracts the ketone, while leaving the catalyst and red
tar behind. This is very good.
then extract with pet. ether a few times. At that point,
The red gunk has (mostly) precipitated out, so a quick
filtration should get rid of most of the gunk remaining,
leaving a fairly clean solution of CuCl2 and PdCl2. The
PdCl2 can be extracted from there with DCM. For added
extraction power, tossing in a little more HCl ought to
persuade more of the PdCl2 to dissolve in the DCM layer.
to get the palladium out. But for larger batches, at
$7/gram (bulk, and only if you're lucky), PdCl2 gets very
expensive.
or two about industrial production, so I figure you'd be
the one to ask. What industrial ketone synthesis would
you recommend? (Hypothetically speaking, of course.) It
seems it isn't a variation of the Wacker oxidation, so
which one is it?
-the good reverend drone
PimpBee
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In my very past, I studied many ways of ketone synthesis,
and based on a few facts, mostly economical, only 2 made
it into the final:
[1]the one from I think UF with the bathtube safrole to
ketone, using PdCl2, and
[2]the performic acid one.
So with those recipees and a "bit" of money I went off to
the far east. There a perfume factory in financial
trouble was found, and after finding out they could not
get PdCl2 in sufficient quantities and on a steady
delivery basis, the choice was made for the performic
method. A lot of resistance had to be mastered about the
environmental aspects of the shitload of remaining
chemicals after the process, untill they found a way to
bring those to a waste-burning facility for a reasonable
price.
We made a setup from two 1000 liter reaction tanks,
rigged together with 3 big watercoolers/boilers and 2
watercooled tanks above that for the starting mix process
of the iso and the rest, so that that mixed together and
was controlled in a sight-glass by 2 valves. It then
flowed to the first 1000 liter water cooled tank and the
rate of flow controlled the reaction temp. A big mixer
inside provided enough vortexes.
After reaction ended, it was tapped in the second 1000
liter tank and 15 % H2SO4 was added etc etc.
That way they delivered every 4 weeks 1000 kg 65 to 85 %
raw MDP2P, which was transported to a seaport and brought
on board the ship under another name on the bill of
loading etc. etc.,then LOTS of trouble to get it in the
desired country where it was distillated to get 98% pure
MDP2P and you may guess what we did then... So,: the
Classical Performic Acid Method, very reliable, allways
ketone, only discrepancy in yields which were never
satisfactedly solved. [Image] LT/
EMOTIONSwill always beFREE!
Hive Bee
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Instead of recovering the Pd what about re-using the Pd
and solvent in solution as is. The goal being to create a
re-ussable catalytic reaction vessel.
accomplished by extracting the oils without extracting
the Pd. A top dwelling extraction solvent would be much
preferred. Possible pet ether, ether, or toluene. Then
once extracted all one would do is add more CuCl2 and
Olefin, then wack away.
memory of what top dwells and what doesn't to make this
work.
Hive Bee
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Spitball-give Curtis Mayfield a credit line for writing
those words and music.
Hive Bee
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Equarius,
there as well. Good thinking, but when this stuff is
over, there is some quite visible impurities that may
have an unpleasant effect on things. Remember this
mantra: garbage in, garbage out.
-the good reverend drone
Hive Bee
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It turns out that LabTop is probably correct about a
bicycle being able to be converted a centrifuge. A.
Gallenkamp and Co. Ltd., London marketed a hand
centrifuge in the past that worked similarly. The tubes
should pivot, and be balanced with .1 gram. One thing
about centrifugal seperations that should be noted is
that the tubes should be spun for at least five minutes,
and then allowed to slow down over a period of around ten
minutes, to prevent particles supernatent solution from
dispersing by swirling.
Hive Bee
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How on Earth are you going to practically make a
centrifuge from a bicycle tire that could separate even a
medium-sized batch of ketone? I'll stick to separation
technology.
-the good reverend drone
Hive Bee
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The same as any other engineer, by building one. I am
looking at a diagram of the aforementioned machine, it
got up to 3000 RPM. It's gear driven like a bicycle, so
his idea could be built by one with enough mechanical
aptitude. Obviously, not every member of the hive is able
to build their own equipment. Some are!
Hive Bee
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A reference that explains how the early centrifuges used
in the sugar industry were built is to be found in
Metallurgical and Chemical Engineering, Vol. XI, No. 6,
p338-9. A basket design is published in Sugar, September
1919, p. 476. These designs are lower speed overhead
shaft drive units that need not be so precisely balanced.
Hive Bee
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I still am not sure as to what advantage a 3000 rpm
centrifuge would have over an extraction procedure, but
if an industrially useful one can be made, perhaps its
not entirely that impractical. I'm curious what these
schemes look like. What is your information source for
the A. Gallenkamp and Co. model centrifuge? I'll give
that other source a try as well.
extraction/separation techniques?
-the good reverend drone
PimpBee
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I wouldn't want to be close when one of those home-made
bicycle-wheel centrifuges loaded with several liters of
spent solvents disintegrated. Good luck.
(Member)
04-12-00 00:06
No 107798
LaBTop [Image] posted 08-02-1999 05:32 AM
PimpBee
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1. I talked about a (Norton Commander)motorbike front
wheel, magnesium or SS reinforced, new, factory balanced
for you nontechnical Neanderthalers [Image].
2. You make friends with a Instrument maker technician at
any university's instrument makers facility (I did it the
hard way and followed a 5 years evening course which
piled up my hobbies to several more, took glassblowing
lessons in the go,too), and let him construct the baskets
and swing arms.
3. That little sucker can easily go to 10.000 rpm and if
you balance out both ends of the axis, 30.000 rpm is no
problem also.
You only need a special motor.
4. The baskets must be weighted out(filled!) with a good
digital balance.
5. You can buy second hand industrial centrifuges at
specialiced laboratory/chemical-plants engrossers
(forestallers, buyer-ups), for amazing low prices.
6. All your big scale/small scale acetone washings can be
done in a cup-formed low speed centrifuge, with a drain
at the bottom, and then constant input from fresh acetone
at the top. In 10 minutes 100 kg/100 gram powder is
snowwhite and nearly dry.
btw, for those interested,buy: Perry's Chemical
Engineers' Handbook, 7th Edition, ISBN
nr.0-07-115448-5(intnl.ed.)or 0-07-049841-5(us ed.).On
the second page it lists another 35 chem.engineering
books of interest! Its circa 1500 pages(no page nr's)
7. Osmium, if you make your own wheely, do'nt forget to
include a segment of thick steel pipe diam. 1m to put the
thing in. If something happens, it happens only to the
steel and not to your balls, which I presume you need for
further adventures into the wonderfull world of
professional sex courses....,or want to preserv for any
further offspring, can't be too carefull with them little
babies...wear a icehockey-protector... [Image] LT/
------------------
EMOTIONSwill always beFREE!
Osmium [Image] posted 08-02-1999 01:33 PM Administrative Options: Close Topic | Archive/Move | Delete Topic Contact Us | the Hive Powered by: Ultimate Bulletin Board, Version 5.43c PAGE 2 *********************************** [Image] [Image] the Hive BB [Post New Topic] [Post A Reply] ymir [Image] posted 08-02-1999 05:06 PM Osmium [Image] posted 08-03-1999 11:44 AM LaBTop [Image] posted 08-03-1999 05:00 PM ------------------ Icepick [Image] posted 10-12-1999 03:27 PM At present, the cost of palladium is low enough to make Palladium Acetate Palladium Chloride. Any spelling errors are mine [Image]. Any other errors Icepick By will alone, I set my mind in motion equarius [Image] posted 02-10-2000 11:56 PM Fasten a keg to the basin of a regular vertical clothes Now, I'm not exactly certain of how a centerfuge works Or, use steel wool (idea from other thread) to convert to hmmm Administrative Options: Close Topic | Archive/Move | Delete Topic Contact Us | the Hive Powered by: Ultimate Bulletin Board, Version 5.43c
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I already have some shots of my juice in the freezer, in
case something goes wrong with my cohones, don't worry
about my future offspring, LaBToP!
And I don't plan to build a wheel, because I'm not into
industrial scale production anymore and still need my
Japanese motorcycle for weekend fun. And I surely won't
rip it apart for a few lousy grams of Pd...
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Hive Bee
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The illustration of a hand centrifuge is to be found on
page 120 of J A Elvidge's and P G Sammes 2nd Ed of "A
Course in Modern Techniques of Organic Chemistry",
published by Butterworth and Co., London, 1966. Doubtless
this product was marketed to schools as an inexpensive
alternative to the real thing. The company has been
acquired by Sanyo, whether they make the product still is
unknown to me. Like the reasonably priced Brinkmann
rotary evaporator, this product probably doesn't exist
anymore. Since it is an illustration of a gear driven
centrifuge, it supports LabTop. Another way besides the
local university to get some help fabricating such
machinery would be to befriend a retired tool and
diemaker, with a shop, since these guys know a lot more
than the average bear
PimpBee
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BTW, why did you use an expensive, rare, way too valuable
Norton wheel? Crashed the bike before and it was left? I
mean, car wheels are almost free and much more common!
PimpBee
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Car wheels: too heavy, too small, too high
and they do'nt have them little holes in them for the
spikes. Remove 2,4,8 pairs of spikes at opposite sides,
voila.
LT/,-you_can't_be_too_caring_for_your_pr
EMOTIONSwill always beFREE!
Hive Bee
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Here is an excerpt from "Palladium Reagents in Organic
Synthesis" by Richard F. Heck pp. 16-17...(printed w/o
permission etc etc)
1.5. Palladium Recovery and Formation of Some
Catalytically Useful Salts
its recovery unneccessary from small-scale catalytic
reactions, although if numerous reactions are run metal
residues can be accumulated. In our laboratory, when
sufficient volume of liquid plus solid
palladium-containing residues are available, we recover
the metal in the following manner. Liquid and/or solid
materials, about 10-20g at a time, are placed in a large
porcelin or other heat-resistant dish and cautiously
heated with a Bunsen burner in the hood. Volatile
material evaporates or is burned off and the solids are
heated with the full heat of the burner for an hour or
two. After cooling, the porous black residue is scraped
from the dish, ground up, and reheated with the burner
for another hour. After cooling, the solid is reground if
neccessary and extracted once with excess hot
hydrochloric acid to remove soluble metals and then twice
with aqua regia. The aqua regia solution is decanted or
filtered from the carbonaceous residue and concentrated
to a small volume by heating in the hood. The resulting
solution is diluted with hydrochloric acid, concentrated
again, diluted with water, made strongly basic with
sodium hydroxide, and the palladium metal is precipitated
by addition of excess hydrazine. The black powdered metal
obtained is seperated by filtration and air dried. The
material is suited for converison into palladium acetate
or palladium chloride as described below.
Palladium sponge (10g)(or recovered powder) was boiled
gently under reflux with a solution of glacial acetic
acid (250ml) and concentrated nitric acid (6ml) in a hood
until evolution of brown fumes ceased. A small residue of
palladium should remain undissolved; if not, a little
more spong should be added and boiling continued until no
trace of brown fumes is observed. This process is
necessary to avoid contamination of the product with
Pd(NO2)OAc. The brown boiling solution was filtered and
allowed to cool, whereupon most of the product appeared
as orange-brown crystals that were seperated, washed with
acetic acid and water, and air dried (mp 205 C dec). The
pale reddish-brown acetic acid mother liquor may be used
for further preperations. The yield was virtutally
quantitative.
Palladium metal (recovered powder, black, or sponge) was
dissolved in aqua regia, the solution evaporated to
dryness, and the residue heated to about 500 C to expel
hydrogen chloride and chlorine. The palladium chloride
remaining was obtained as a brown powder.
are not, just quoting what was found in an interesting
book. Hope this helps kids,
Hive Bee
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Consider this for large runs using 10g+ (look ma process
a kilo).
washer to the side of the center column. Counterbalance
with an equal weight on the other side. Hack off the lid
and plug the little open / close activation switch. Set,
or hack, the washer to spin and centerfuge away.
except that there is spinning involved. Does the spinning
vessell have to be the center of rotation or is offset
(as I described above) the correct way?
Pd(0), then centerfuge.
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04-03-02 05:02
No 291678
1. Precipitate Pd out of the solution with PdDMG
2. Dissolve PdDMG in excess NH4OH sol., boil, then add
HCl to crash out Pd species as easily-filtered palladium
yellow, Pd(NH3)Cl2
Now those extra amine ligands are a pain-in-the-ass, as
They are bonding to the palladium right where our
catalyst friend does its magical thing, but this may not
be too much of a problem. Those amines are very
loosely-bonded ligands.
That's not really correct. If you read the article pertaining to the O2 wacker in the Eur. Journal of Organic Chemistry 1998, 1901-1906, you will see that the amine ligands actually increase the selectivity of the catalyst. These ligands probably are temporarily displaced by the olefin in the complex formed during the reaction.
Also, there should be a temperature below the dec. point that these ligands will come off. They are bound in the same fashion that water is bound to the dihydrate, so should come off at an even lower temperature since N is less nucleophilic than O. Don't quote me on this, though. It's just a guess.