I came across an interesting very old thermochemical hydrogen cycle.

I like to mock the bullshit around here dragging out the tiresome fantasies (or Exxon type promotional stuff) to greenwash fossil fuels as "hydrogen" - this with exergy destruction, lowering the energy value of the fossil fuels themselves - and so I've taken to posting articles from decades ago when the ideas around this bullshit first started appearing. Same shit; same thermodynamics.

A recent example of such a post on these regressive ideas is this one: A solar-hydrogen economy for U.S.A., which dates from 41 years ago.

In that post I called up a paper that seemed less stupid then than it clearly is now, now that the trillion dollar "solar will save" fantasy has been explored and has soaked up trillions of dollars for no result other than the destruction of wilderness and continued reliance on dangerous fossil fuels, the use of which is growing faster than ever.

The paper linked in the post was this one: A solar-hydrogen economy for U.S.A., International Journal of Hydrogen Energy, Volume 8, Issue 5, 1983, Pages 323-340.

All this said, hydrogen is an important captive industrial reagent, which is appropriately handled by highly trained chemical engineers, the production of which the world food supply now depends owing to the industrial Haber-Bosch process to make ammonia, and thus I am interested in realistic, not pie-in-the-sky so called "renewable energy" schemes to make it. Thus I am interested in thermochemical hydrogen production scheme using nuclear heat; many variants are known, my favorite being one of the first considered, the sulfur/iodine cycle.

When opening the old journal about putative "solar hydrogen" I came across another paper that caught my eye this one:

O.H. Krikorian, P.K. Shell, The utilization of ZnSO4 decomposition in thermochemical hydrogen cycles, International Journal of Hydrogen Energy, Volume 7, Issue 6, 1982, Pages 463-469.

It posits a modification of the SI cycle relying on the decomposition of ZnSO₄ to generate SO₂ and includes a selenium intermediate.

The reactions are these:



It's funny because just the other day, while driving, I was musing on the decomposition of H₂Te, tellurium being a congener of both selenium and sulfur, so it caught my eye.

I immediately upon coming across this cycle, began to think of paths to eliminate sulfur from the series of reactions and have begun poking around in the literature for the properties of ZnSeO₄; I'll discuss these ideas with my son who is visiting for the holidays.

I've thought about zinc based thermochemical hydrogen cycles, and have thought about the SI cycle as well. This new variant is either syncretic or completely different. I've filed these papers under ZnO cycles in my directories.

I wish you the happiest of holidays; and I hope you're enjoying a successful engagement with the consumer stuff festival.