Post by: ildiTHS on May 27, 2014, 10:12:17 AM
I am looking for a hydrogenation reaction, which can be included into a curriculum material for undergrads. The reaction should match the following criteria:
- gives good results using heterogeneous catalyst and H2 gas
- the heterogeneous catalyst can be RaNi
- changes color
- interesting for a student
- starting material can be dissolved in a green solvent (ca. concentration: 0.05 M)
- advantage:
:rarrow: shows different results at atm. pressure and higher
:rarrow: highly temperature sensitive
:rarrow: would teach them something about industrial applications...what is waiting for them after graduation
I would use this reaction with a brand new flow system, which allows reaction optimization in hrs,can work up to 100 degree C and 100 bar with in-situ generated hydrogen (I am not kidding, http://thalesnano.com/products/h-cube-series/H-Cube_Mini), so even just "maybe"s would do for me without exact parameters. The more interesting and difficult the better.
Thanks,
Ildi
Edit: fixed the rarrows
Post by: Corribus on May 27, 2014, 11:32:12 AM
If you're looking for a visible color change, you could try a porphyrin or possibly a conducting polymer like MEH-PPV. I've never tried to hydrogenate them, so you'd either have to search the literature or just try it out and see what happens.
Make sure to use a blast shield!! :)
Post by: Archer on May 27, 2014, 05:52:22 PM
![[O-][N+](=O)c1ccc(N\N=C(/C)C)c(c1)[N+]([O-])=O](https://www.chemicalforums.com/SMILES/e87e322772ebb57a7ac8.png)
This may change from yellow to orange under lower pressure as the C=N bond is hydrogenated, as the pressure is increased and the nitro groups are hydrogenated the red colour should be removed.
I have never tried this experiment so I make no guarantee that it will work as described above.
There are some other hydrogenations which cannot be discussed on the open forum but I can give you some details in a PM if you are interested.
Post by: ildiTHS on May 29, 2014, 04:49:22 AM
Thank you for your answers. The conductive polymer is so cool, I have to get my colleagues to give it a try.
Archer's example is excellent!
Thanks for giving some works for the guys in the lab ;-)
If you have further idea I am happy to receive them. Archer, please send the confidential one(s) to private message, I am very interested.
Regards,
Ildi
Edit: forum rule violation - post no addresses - please read forum rules
Post by: curiouscat on May 29, 2014, 05:30:07 AM
That blast shield & "cannot be discussed on the open forum" parts effectively eliminate those from consideration as undergrad curriculum. :)
Post by: Corribus on May 29, 2014, 09:55:14 AM
If you can get a conducting polymer like MEH-PPV to react with hydrogen, progressive saturation of the vinyl linkages should lead to a color change (blue-shift) by restricting the exciton delocalization length. This is also a good way to show students the particle-in-a-box model of introductory quantum chemistry. I actually published a paper on this a few years ago, although we used a chemical oxidant to saturate the vinyl linkage rather than hydrogen. Doing it with hydrogen would be an interesting reaction to try actually. I'm intrigued by the possibility. :)
Post by: ildiTHS on May 29, 2014, 10:36:40 AM
Post by: billnotgatez on May 29, 2014, 11:00:50 AM
If I got this correctly
Your company makes this device that creates hydrogen in a safe environment.
And, you are asking us for experiments that can be used in a safe way to teach students.
In other words, help you with demonstrations so you can sell your products to teaching institutions.
My curiosity has got me here
What is the cost of operating your equipment compared to electrolysis of water producing Hydrogen.
We can neglect the cost of your system purchase (that can be found on your web site).
I am interested in the cost of supplies and energy.
It would also be interesting if one purchases a tank of hydrogen for a gas supplier what the difference in cost with your device (still neglecting the purchase cost of your system).
Notice I am also neglecting safety considerations here (I am assuming your system is safer for this question).
Bill
Edit: The words in red added latter to do a suggested fix from a later post
Post by: ildiTHS on May 30, 2014, 04:53:38 AM
When you wrote "electrolysis of Hydrogen" I believe you meant: electrolysis of water. FYI: this is what is used in our systems to generate hydrogen.
Please let me not to really reflect to your other offensive comments, but recommend you to search for "flow chemistry", you will find many scientific articles and books: green chemistry related, industrial applications from pharma, agrochem, F&F, petrochem etc.; and loads of papers from academia too. They can prove what this technology can do, the benefits and weaknesses too.
Have a great day,
Ildi
Post by: curiouscat on May 30, 2014, 06:17:03 AM
Please let me not to really reflect to your other offensive comments, but recommend you to search for "flow chemistry", you will find many scientific articles and books
I didn't see any offensive comments. What did you find offensive?
Post by: ildiTHS on May 30, 2014, 06:42:25 AM
Mainly the style, and the fact that instead of offering an answer the whole comment focuses on "it must be just a trying to sell an expensive product".
But actually it opens another question for me: I am realtively young, so I cannot remember, but were the chemists so neglegtive when the first GC, LC, NMR, IR etc instruments were introduced? Was it so "difficult/not wanted" to switch from TLC to e.g. LC, like it is sometimes so unbelievable to do a reaction not in a flask still today?
Post by: curiouscat on May 30, 2014, 06:48:41 AM
Hi Curiouscat,
Mainly the style, and the fact that instead of offering an answer the whole comment focuses on "it must be just a trying to sell an expensive product".
But actually it opens another question for me: I am realtively young, so I cannot remember, but were the chemists so neglegtive when the first GC, LC, NMR, IR etc instruments were introduced? Was it so "difficult/not wanted" to switch from TLC to e.g. LC, like it is sometimes so unbelievable to do a reaction not in a flask still today?
Ok. I can see what you mean. But I'd characterize it more as skepticism than offensiveness.
Here's my take on it: I get to meet so many clueless sales engineers trying to oversell technology that the few genuine, honest, knowledgeable guys might have to suffer a grouchy me.
So, don't take it personally. If you sell novel technology be prepared to meet skepticism and suspicion. Sales needs a thick skin. :)
Post by: curiouscat on May 30, 2014, 06:52:04 AM
I'd love to hear (just out of curiosity; I'm not sure this is a market you target?) what price per kg H2 your technology works out too.
Hey, who knows? Maybe it might just be the right technology for us. We still do conventional batch hydrogenations, often on a 10 kL reactor scale. You can imagine we'd love to go flow reactor if only the price works out. :)
Post by: ildiTHS on May 30, 2014, 06:54:12 AM
Post by: ildiTHS on May 30, 2014, 07:00:20 AM
Hu...you work with such a big scale! I should pass this question to my engineer colleagues, I am "just" a chemist, I can think in mgs and gs. Can you send me in private email your contact data. I do not think the moderators would welcome if I put here the full details of my company and colleague ;-)
Post by: curiouscat on May 30, 2014, 07:25:02 AM
I should pass this question to my engineer colleagues, I am "just" a chemist, I can think in mgs and gs. Can you send me in private email your contact data (...)...I do not think the moderators would welcome if I put here the full details of my company and colleague ;-)
I've sent you a PM on here.
Post by: Borek on May 30, 2014, 08:11:08 AM
Post by: discodermolide on May 30, 2014, 09:20:46 AM
Post by: Corribus on May 30, 2014, 10:08:12 AM
Post by: discodermolide on May 30, 2014, 12:38:02 PM
Post by: billnotgatez on June 03, 2014, 06:01:58 PM
@everyone
I did not expect that my post would generate so much and detract from the original question asking for safe hydrogenation reactions (see original post).
@ildiTHS
From reading your original post and I assumed your device was proprietary plus I assumed your device was designed for safety, the only metric I could think of was operational cost. Then one could justify your system versus extra insurance costs needed for other methods of producing or handling Hydrogen. I guess one would have to factor in the initial cost of your system from another system, but I was willing to forgo that since it would be eventually amortized. Unfortunately, I do not have the time to spend to extensively look at your company's web site, so I was looking for a quick answer from you. If it is not easy as that then I understand. I was just looking for a metric and was curious.
@curiouscat
I liked your entry
Quote
Hey, who knows? Maybe it might just be the right technology for us.It fits my sentiments.
Post by: ildiTHS on June 11, 2014, 08:50:38 AM
I try to give you an estimated operational cost, sorry in advance it will not be really exact.
Directly chose a more complicated system, not the cheapest which require less energy:
Power requirement:
115-230 VAC
5A/115VAC
2.5A/230VAC
47-63Hz, 300W
The system needs an HPLC pump too, its power requirement: 100-240VAC, 1.3A, 47-63Hz, 55W
If 1 kWh costs e.g. 0.2 EUR, then 0.355 kW if it is used 8 hrs/day, 20 days in a month: 11.36 EUR electricity.
Plus you will need distilled water, 200 mL should be enough for about a month (it was said that with "average use" it is enough for 3 months), it should not cost more than couple of Eurs.
Then you need catalysts (well...for batch reactions too), depending on your chemistry of course it can cost you a lot, but just an example lets calculate with using 2 different catalysts every day... appr. 1000 EUR/month...if it is Wilkinson or enantioselective, then this cost will be much higher.
Then finally: solvents and starting materials...in flow we recommend using 0.05 M as a starting!!! concentration...yes it is very low and it needs lot of solvents, but actually it is just the starting concentration to check if the catalysts works at all, then of course the concentration should be increased. One of the highest concentration I saw from our lab was 0.7 M (for hydrogenation and our target is not to produce compounds then sell them), I saw 1.0 M too from others....when the reaction is homogenous then obviously much higher, the heterogeneous reactions usualy require that 0.7 M max. concentration, but it can be precalculated based on the H2 production, flow rate and stoichiometry of the reaction. Hard to estimate a cost mainly because of the starting materials.
Others: no special paper is needed, no certificate (from your side, we do CE), no special lab, no cylinder (unless you want to use O2 or O3 etc.). But you will need a fume hood.
That is all I think.
Post by: curiouscat on June 11, 2014, 09:08:16 AM
Then finally: solvents and starting materials...in flow we recommend using 0.05 M as a starting!!! concentration...yes it is very low and it needs lot of solvents, but actually it is just the starting concentration to check if the catalysts works at all, then of course the concentration should be increased. One of the highest concentration I saw from our lab was 0.7 M (for hydrogenation and our target is not to produce compounds then sell them), I saw 1.0 M too from others....when the reaction is homogenous then obviously much higher, the heterogeneous reactions usualy require that 0.7 M max. concentration, but it can be precalculated based on the H2 production, flow rate and stoichiometry of the reaction. Hard to estimate a cost mainly because of the starting materials.
Just to add a comparative data point. Our industrial hydrogenation (MeOH solvent) typically operates at ~5.5 M conc.
This is in a large batch reactor with hetrogenous catalyst. At lower conc. the cost of stripping away the MeOH post reaction is large.
Post by: curiouscat on June 11, 2014, 09:09:51 AM
Power requirement:
115-230 VAC
5A/115VAC
2.5A/230VAC
47-63Hz, 300W
The system needs an HPLC pump too, its power requirement: 100-240VAC, 1.3A, 47-63Hz, 55W
If 1 kWh costs e.g. 0.2 EUR, then 0.355 kW if it is used 8 hrs/day, 20 days in a month: 11.36 EUR electricity.
Plus you will need distilled water, 200 mL should be enough for about a month (it was said that with "average use" it is enough for 3 months), it should not cost more than couple of Eurs.
That's all good but as a basis how many kg of H2 is that equivalent to producing? That'll give us a basis of comparison.
Post by: ildiTHS on June 25, 2014, 02:30:34 PM
in 20 days 576 000 NmL.
In a 300 bar tank, appr. 300 x more H2 can be stored, so 1920 mL 300 bar hydrogen tank is equivalant with this monthly production.
Post by: billnotgatez on June 25, 2014, 04:28:09 PM
did I convert correctly?
I wish there were more suggestions for safe teaching uses.
Post by: ildiTHS on June 26, 2014, 06:26:55 AM
Welll...the original topic changed by the time that is for sure. But actually I have never made these calculations before, and even I am impressed.
Post by: curiouscat on June 26, 2014, 07:34:38 AM
For me it is rather 576 liter. I must have done a wrong calculation somewhere, it sounds too much from a "small box".
Probably because you are used to think in terms of Liq. volumes. 576 L of a gas at atm. pressure isn't a lot.
If I did my calculations right that's barely 46 gm of Hydrogen?
That's tiny.
Post by: ildiTHS on June 26, 2014, 01:23:48 PM
Post by: curiouscat on June 26, 2014, 01:41:51 PM
for me it results 47 g (24.5 dm3 = 24.5 liter = 1 mol, so 576 liter = 23.5 mol)
Close enough.
But now forget consumables but just the capital cost of your system spread out over 46 gms a month (or 47 :) ) will make it incredibly expensive I suspect.
Say, depreciated over even 5 years which is fairly long. Imagine not even making 10 kg of H2 over the whole life of the system?
Either your calculations are wrong or something else.
Post by: ildiTHS on June 27, 2014, 02:52:55 AM
I do not know.. almost 2 liter 300 bar cylinder is equivalent with this amount...monthly, I would not call it tiny, in few months it is equivalant with a full cylinder, but you do not need to worry about any aspects of safety, pay for the paperwork, transportation, training (if you need to those who are allowed to operate a cylinder), storage, then getting a new one and starting from the beginning. Not mentioning that it is a continuous production of hydrogen, and the efficienty is much better...plus the safety aspects of not having to use a cylinder.
Personally I really do not like opening and closing any cylinders, even nitrogen.
Post by: curiouscat on June 28, 2014, 11:56:13 PM
Sorry, when you wrote 46 gm for some reason I saw milligram.
I do not know.. almost 2 liter 300 bar cylinder is equivalent with this amount...monthly, I would not call it tiny, in few months it is equivalant with a full cylinder, but you do not need to worry about any aspects of safety, pay for the paperwork, transportation, training (if you need to those who are allowed to operate a cylinder), storage, then getting a new one and starting from the beginning. Not mentioning that it is a continuous production of hydrogen, and the efficienty is much better...plus the safety aspects of not having to use a cylinder.
Personally I really do not like opening and closing any cylinders, even nitrogen.
Maybe. For educational users perhaps, but industrially it seems a no go.