[curiouscat]

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.

[Borek]

Please don't post emails in the open forum. That's against the forum rules (and common reason, unless getting spammed by bots is what you are trying to achieve).

[discodermolide]

I might add here that 0.05M is very dilute for a reaction. And there is no such thing as green chemistry.

[Corribus]

Unless it deals with chlorophyll.

[discodermolide]

lol

[billnotgatez]

Back from a long weekend

@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

Hey, who knows? Maybe it might just be the right technology for us.

It fits my sentiments.

[ildiTHS]

Hi,

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.

[curiouscat]

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. 

[curiouscat]

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.

[ildiTHS]

With the above data...it generated 60 NmL/min H2 (max.), so 28 800 NmL in 8 hrs.
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.

[billnotgatez]

0.000576 Liter in 20 days
did I convert correctly?

I wish there were more suggestions for safe teaching uses.

[ildiTHS]

For me it is rather 576 liter. I must have done a wrong calculation somewhere, it sounds too much from a "small box".

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.

[curiouscat]

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.

[ildiTHS]

for me it results 47 g (24.5 dm3 = 24.5 liter = 1 mol, so 576 liter = 23.5 mol)

[curiouscat]

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.