Hydrogen Gas Generator vs. Hydrogen Gas Cylinders

[aaronrodg]

Cylinder hydrogen supplies are the simplest sources for labs but present a safety, cost, and handling concerns, particularly associated with cylinder change-outs. Generators tend to be more up-front expensive than cylinders but offer safety benefits as well as benefits of continuous supply and consistent purity. They are particularly attractive alternative for larger labs where large hydrogen supply can present larger safety risks, and larger operating costs.

[Steve Reimer]

In our lab we tried using a H2 generator for a while but it wasn't a success. I think the problem was what James hinted at, it was undersized and overworked. We had 3 failures in 2 years.
The last one was under warranty so Parker took the unit back for repair and lost it. They finally sent us a refurbished one several years later and I never took it out of the box.

[James_Ball]

In our lab we tried using a H2 generator for a while but it wasn't a success. I think the problem was what James hinted at, it was undersized and overworked. We had 3 failures in 2 years.
The last one was under warranty so Parker took the unit back for repair and lost it. They finally sent us a refurbished one several years later and I never took it out of the box.

One thing to look out for as we found was leaking valves. Our benches have the faucet type valves for each gas, and apparently the seals are not compatible with hydrogen. Even ones that are always fully on have been found to be leaking. Once we replaced those, the hydrogen generators supply more than we need and have been a great investment.

We have also switched to using a nitrogen generator which supplies our ECD makeup gas. The generator works great, our only problem with nitrogen has been keeping an air compressor working. The first two were hardware store units, but now we have an industrial grade dual stage one that should keep up. You just have to make sure when going to generators of any type that your lab infrastructure is also ready for the switch.

[James_Ball]

We are using the Parker Balston unit that makes 1100ml/min at 120psi input. We can get a stable 75psi out even running it near capacity. Just be sure you have enough air compressor to run it.

[aaronrodg]

Just bought a new Parker Balston unit...working great!

[Jake]

Less than a year later, with very minimal use, our old H2-500 failed again. Couldn't really figure out what the problem was: bad water leak, which we couldn't locate, and the unit was under full load even when we weren't delivering any H2. A bit disconcerting that it didn't automatically shut down. Perhaps it eventually would have. Obviously a very poorly-designed unit. We retired it.

As a word of caution: inspect those dionizing bags carefully before inserting into your water resevoir. One of ours 'leaked,' so we had to spend a lot of time carefully removing all the resin from the resevoir, lines, etc. Not fun. In general, we've noticed that the PM kits are of very shoddy quality with poor QC. So inspect parts before use, and save the old parts just in case. Still no problems of consequence with our H2-1300 (supplying four GCs) and our H2-800 (1 GC, two channels). Very happy with those units.

[antonk]

http://chromatec-instruments.com/produc ... enerators/

Feed this with 1x10E6 Ohm/cm deionized water and forget.
The only maintenance - flush water when not in use.

After 5 years H2 production might slightly fall when your water quality is not good enough - then you can replace the cell (6 bolts and 2 fittings).

we have sold ~50 of these machines. What was repaired (5 machines after 3-5 years of exploitation):
* cell replacement due to bad water or wrong exploitation conditions (long spare time without flushing water). As soon algae starts growing in tubes - you got a problem.
* separator valve replacement. 1-way valve which flushes water from separator. Can be ordered from Camozzi. Corrosion in valve due to long spare periods without flushing water.

as soon it is russian production (lots of nuts and bolts) - in can be completely disassembled and washed.

[Hornet]

We have been using the H2 generators for about 6 years now. The first Parker unit lasted about 4 years it was the H2-800 unit. I think a small leak caused it to work too hard, and killed it. We replaced it with two Proton on Site 600ml/min units and for a year we were barely keeping pressure on the line. I found a leaking valve and replaced it and now we only refill the water once a week. These supply the entire building with carrier for about 10 GCs and fuel for 6 FIDs. Since we also have the tank farm outside we keep a cylinder of Hydrogen online but have the pressure regulator set 20psi below the line pressure with a check valve on the line, so that if the generator fails the line pressure will only drop from 70psi down to 50psi and the cylinder will take over as backup. This also helps if we need to do maintenance on the units, to supply gas while they are offline.

I think we paid for both of the new units in one year with the savings over what the cylinders cost, so even if they go out after three years we have made money on them. The new units use a molecular sieve moisture trap instead of the palladium membrane, which means a little more maintenance but less expense of the units. The only gas we have to keep in cylinders now is Helium for the GC/MS units, if I can ever make them tune with Hydrogen I will switch them over too.

Hello James. I recently installed a H2 generator for my GC lab and i would like to use gas cylinders as backup, like you did in your lab.
I wanted to install a check valve as well, i just wanted to know if you could tell me the model you used.
From swagelok i only see an adjustable check valve in the 50 psi range and it doesn't come with 1/8 inches tube fittings...

Edit: nevermind, i have found the adapters somewhere in the lab

[Jeanette]

Have been using H2 cylinders for about 2 years and for three years ago i found a Parker 9200 on e-bay in really good condition, almost as new for a really good price. Off course it was a bit of a gamble but this time i was lucky.
Changed the desiccant, poured some distilled water and it was good to go. 250cl/min @ 100PSI non stop. if there is a leak it shuts down without any problem. I could never think about buying H2 cylinders ever again.

But now i bought a Varian MS/MS and H2 gen is of no use. Back to Helium cylinders ... too bad the sun is so far away =)

[david lai]

I would have a look at some peak scientific Hydrogen generators, they come in modular forms so you can pick what you need if you have house air need additional Zero air or nitrogen as well.

The service is quite good depends on what you want 24-hour cover if you need it, but the best thing about it is they do the repairs on-site, so no losing the generator or the shipping time.

https://www.peakscientific.com/products/hydrogen/