I would like to share some random thoughts I have had while reading through this thread. I am impressed by the work developing the tec, and maybe we could further revise it. Most of my thinking out loud will be on improving safety.
As noted previously on the thread, the process can potentially result in catastrophic explosions. Thankfully, nothing like this happened to any of the home tec experimenters, but I have to say I was concerned to hear sometimes the plastic bottles looked like they were about to burst.
Looking at best practice recommendations for pressurized vessels, the vessels should be individually pressure tested using water and no hydrogen before being used. Hydrostatic pressure testing is discussed, e.g. here .
For those who want to monitor closely (ahem… but at a distance) to minimize risk, the same instrumentation could check pressures during any hydrogen generation, to ensure the pressure doesn’t exceed maybe half what you pressure tested (e.g. if the vessel survived 70 psi, keep pressure under 35 psi.) If you want to pressure test even higher psi’s, it becomes more expensive e.g. long braided hoses that have been pressure tested.
I realize not everybody is concerned about endocrine disruptors from plastics undergoing physical and chemical stress, but I am. Stainless steel Cornelius kegs therefore crossed my mind as candidates for vessels. They have a wide mouth for easy cleaning and are designed with safety valves to release pressure at 130 psi. However, I am not sure sudden release of hydrogen at that pressure is much safer than an explosion, due to ignition potential. Probably, a lower psi pressure relief valve is advisable, with venting outdoors. Also, compared to a bottle, a keg is a bigger bomb, and the total reactants you put in it would need to be carefully limited.
Cleaning/sterilization is important, and kegs with relatively seamless machine welds are better than manual welds, as they provide less cover for microbes.
With regards to purity of the reactants, I realize the conversation shifted to relying on the test-tube-in-a bottle model. Nevertheless, some comments on the thread referred to off-tastes/smells, so I am not sure this filtering provides sufficient protection if the reactants include contaminants. Personally, I would opt for more expensive reactants from a place like Sigma Aldrich, ideally with filtering on top of that.
I don’t know if anyone tried a GL45 vented cap with a 0.2 µm PTFE membrane such as this one to isolate solids and liquids in the “test tube.”
With regards to H2-containing air (HCA) vs. oral intake of H2-rich water (HRW), it makes sense to me that one study concludes “the combination of both HRW and HCA had the most potent effects on signaling pathways and gene expression in systemic organs.” To me it’s just a question of what is the optimal ratio of gas inhalation to drinking hydrogen water. Since purity and production safety with hydrogen water is expensive, and the minimum dose for ghrelin effect is very low, I would place the emphasis on inhalation, with low-concentration hydrogen water as an adjunct. Mechanical mixture of hydrogen gas and water, as discussed previously on the thread would provide a low-concentration drink that would keep costs down and add unique benefits.
Putting controversies aside, I appreciate the hydrogen inhalation tecs provided by my namesake adamh, and would just like to run by people a slightly different collection method: place the magnesium and citric acid solution in a capped glass jar that has an air lock to filter out aerosol droplets. For example, http://www.pickl-it....roducts/singles (just make sure the jar is tall enough for your rods). Clamp an aluminum balloon on the airlock. For best safety, do this outdoors in a wide open yard, and not under a roof overhang. That’s it.
I know some might think I am too concerned about contamination and production safety issues, but I am still thinking there must be things I overlooked, and that any hydrogen production method needs to be carefully examined.