I would appreciate any details that I should consider before starting my treatments.
It is not safe, because you are using pure hydrogen that could leads to explosion. Sometimes it could leaks in the tube even you already make the gas tight end seals.
I totally agree with Simon's advice. A flow is definitely much better than a hot static system. But even cylinders of hydrogen, pure or diluted, can not be stored everywhere and may cause problems. In this case, better using a small H2 generator based on water hydrolysis. Such small generators are much preferred in labs, and turn to become cheaper at the end than hiring cylinders. Finally, your reduction system can be installed in a glove box filled with inert gas. Therefore, in case of leak, nothing happens.
Alain
Thanks Nur, Simon, and Alian for your comments and I appreciate the time you spend. I will not definitely do it under static Hydrogen and I will have a flow, e.g. 300 sccm, of Hydrogen. There are some hydrogen safety systems on the market which can detect LEL and UEL and purge the system with an inert gas accordingly. But they are so expensive. The attached please find a summary of gas safety system.
I can not use 5% H2 balanced with either Ar or N2 because I need extremely reducing environment for my samples. Maybe,he best bet for us would be to find a research group who already these type of treatments before and send our samples to them,
Esmaeil, H2 is scary when you hit the explosion threshold in air which is 5%. If you are are going to flow such a low flow rate at moderate temperatures you should be able to make your own system. I have been working with H2 at much higher flow rates at temperatures up to 1650 C for years. Please let me know if you want me to help you build you system based on what you have.
Yousef, We were looking at to purchase a atmospheric control tube furnace from either Carbolite or NaberTherm.
For safety, the only plan that I had was to purge the tube with Argon before and after introducing Hydrogen to make sure that we already kicked oxygen out from the tube. We could also run the tube furnace under a fume hood to make sure that we have enough ventilation. If you have any other details that could be add to these I would really appreciate it if you could share them with me.
Purging the system is a must when you use hydrogen. I need to know some more details like temperature, dimensions, what materials are you going to make from ....etc. Feel free to send me private messages if you prefer so.
All above discussions make sense. What I can add are:
(1) The safety goes beyond the furnace itself. Storage of gas cylinders and gas connections need to meet regulations. This includes compliance with volume, other gas cylinders (e.g. oxidising gases), and distance to ignition sources (e.e furnaces).
(2) There are portable gas sensors available with reasonable price (about US$1000). This is very helpful in detecting any leaks. Just reminder that the electrical cell type CO detectors respond to H2 (and other chemicals with -OH group) as well.
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