With all the talks of “new” conversions using Pdc, I thinks it’s “high”() time to have a conversation about it’s safe handling considering it’s a pyrophoric catalyst. I, for one, have been reading up a lot about it (as I do everything) for safety before attempting ANYTHING.
What do the “wizards” here have to say on safety tips on its handling, use, and reclaim? There’s going to be a lot of people (myself included) that will be using this precious metal in the very near future. I feel confident in its handling but hoping others are taking the same precautions as I do on reading, researching, and applying all the safety protocols with its use.
When at university we used this all the time. Most of the time it came in units that were easy to handle AND already kept away from the atmosphere - like magnesium and sodium did as well.
There were some sweet solid state ones back in the early 2000’s - that you could drop in and then cleave a coating off and bam away you are going.
Its the regenerating of the catalyst that I think is the most important part (like people will figure out how not to catch themselves on fire…probably…maybe?) but how do you reclaim it? How do you reuse it? How do you not have to throw that shit away using special haz waste?
That was the biggest thing I dealt with from bench to industrial scale up - how can we handle this in larger quantities and be efficient and not waste it. You know? A small article on some cleanup and reactivation.
Its also worth noting that hydrogenation can happen without any catalysts if you want it to do so…
And here’s a guide by a partner university that I worked with back in the day about safe handling.
See… that’s why I’m talking about! Some of us that aren’t trained chemists but have a good grasp learn as we go! That’s some great info! Appreciate ya chimin in @Cassin !
The reactivation and reuse is something that’s of great interest to me in the realm of safety. Luckily, my local university is willing to do that for me . I’ll learn while they do it and once I’m comfortable, will tackle myself.
Ultimately, metal prices and synthetic/engineering prowess are what will drive market values for these products. Its going to come down to who can use the least/cheapest catalysts, and who can safely scale the furthest (or who can afford to float tens of thousands of dollars in metal that they either can or cant recover or buy extremely pricely hydrogenation equipment).
This little space race may truly gonna separate the professionals from the guess-and-check enthusiasts. It will be very telling when the guy next to you is able to offer a price you could never yourself match based on your catalyst choices/handling cost alone. Good luck to anyone getting into this chemistry who isn’t already keenly aware of how to use and recover materials that cost over $50-100+ per gram.
All valid points. It is quite expensive but, from my understanding, minimal amount is used for hydrogenation and oxidation (1%-3%) and can be used quite a bit (depending on load weights) before needing recharged.
More catalyst=faster reaction=more usage.
But, using less, I feel, would be safer in the realms of being a hazard (fire).
Guess I’m on the search for someone versed in this catalyst so I can get a better grasp on the reactions with these awesome catalysts.
Any takers?
Can it be used to oxidize D9 for compliant CBD by converting the D9 to CBN? Is this method scalable? Can it be used to completely convert to CBN (believe I’ve read it from a few that it can be)? Is a solvent needed? Can it be ran neat?
If youre running a hydrogenation you have one chance to charge your Pd/C (at the beginning), and if it dies before the hydrogenation is complete you’re going to have to stop the reaction, filter and concentrate and run it again to from step 1 to achieve complete conversion. You can’t just open the vessel and charge more Pd/C, palladium isn’t forgiving like that. And 1-3wt% is still considerable on a multiple kilogram scale using precious metal…
So while you obviously want to use less catalyst than more based on cost, you definitely want to use enough that your confident that the reaction will be complete otherwise your product is inferior to someone who DID run it to completion - not to mention you use way more time/catalyst re-running the reaction in order to complete the conversions of all THCs to HHCs. Rerunning a half complete reaction still requires the same catalyst loading. Using less catalyst isn’t really a measure of safety at all, it’s directly tied to process cost and reaction time/completion.
Edit: with this in mind, trying to re-use hydrogenation catalyst without ensuring it’s still active is not a smart move. Say it’s only 50% active after the first reaction? You’d never know from just looking at it. Then what? You run a hydrogenation with it that doesn’t go to completion and then you waste a ton of time having the run the material again.
I use notable ammounts of the Pd catalyst (several cages with 100s gs of pelett) to scrub trace O2 from a glovebag under N2:H2 atmosphere (95:5).
In my case this is is more exactly Pd on alumina (not carbon), 5%.
O2 and H2 react at the surface to produce H2O and some heat. It is very efficient, and if the system is hermetic enough, one can maintain low O2 (below detection at 2ppm) for month (ensuring high enough H2 in the air, idrally 3-5%). Catalyst must be sometimes regenerated by simply heating at 150c overnight go dry it out…
One time, I had not used the bag for a while, and didn’t know the O2 detector was faulty, and not functioning anymore (indicating 10ppm instead of 1000s…). I introduced 2 regenerated catalyst cages. I noticed the bag getting foggy in few seconds, and the cage got really hot. I could feel high heat with several pairs of gloves. The cages got hot enough to melt a PS box there were leaning on…
In fact they might have been a bit too much O2 in there (with high H2), when the cages were entered. Fortunately, the reaction only lasted for few minutes. And I could rapidly transfer them to the airlock to vent them with N2.
This kind of reactivity shows how fast it can heat up and eventually catch fire if both oxidant and reducer (reacting exothermically) are present in sufficient quantity at the surface.
Also yes people use this to oxidize to CBN. Considering palladium can be used to make a way cooler serious of molecules (hydrogenated ones) it always seemed like a piss poor use of the metal. I’ve not run the reaction because again, silly way to use valuable metal, but my understanding is that for making CBN it’s very high temperature, long reaction time, and a conversion of maybe 50% but results vary tremendously in terms of reaction duration and final conversion.
I can’t believe people use a catalyst they could be hydrogenating with to make boring old CBN…
That was my understanding. I just meant being able to reuse it numerous times once it’s recharged (sorry for my lack of chemistry jargon ). That it doesn’t degrade. Like using an acid once.
So, would charging it during the reaction be more viable then say putting the pdc into a vessel and “precharging”?
I worry about cleaning up the elemental sulfur in the CBN reactions. Figuring this would be a cleaner method.
I also ran across this in some literature. I believe it was nickel that was used though. Would have to dig back through everything.
The question I get hit with the most (and I don’t have the answer to) is after the reaction, how to handle the catalyst. @thesk8nmidget said people were filtering it out, putting it on ashless paper, and burning the paper.
Seems viable if running a neat reaction but, what about someone adding a flammable solvent to the reaction? Wouldn’t that be a bit… dangerous?
@Roguelab talked about this a while ago on a topic brainstorming the use of Au I believe. I don’t think this is the route in a bath of boom sauce though.
You can sacrifice a fritted filter and filter it to a moist slurry and scrape it off. This will 100% clog the filter frits over time, but no celite mess.
You can’t charge Pd/C in the middle of a reaction, that’s what I’m saying. You may only add add at the beginning, you get one chance to choose the correct amount so you want to know how active the catalyst you add is. Attempting to add the catalyst in the middle of the reaction is dangerous.
) time to have a conversation about it’s safe handling considering it’s a pyrophoric catalyst. I, for one, have been reading up a lot about it (as I do everything) for safety before attempting ANYTHING.
