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this post was submitted on 03 Mar 2024
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Hydrogen from electrolysis comes from clean water. You know, the stuff we drink and water our plants with that’s getting more and more difficult to come by? I’d rather not see the oil industry turn water into the new gasoline.
That is incorrect, because salt water electrolysis is a thing - actually so much more efficient even, that they salt fresh water because it takes less energy. Not only that - the plant which I indirectly work for uses grey water. You know, that stuff that you flush down the drain?
Which is great, but I'm sure your plant deionizes the water before using it in the electrolyzers, right? So the water is still being purified, just not by a public water plant.
I hope you are correct, because companies like Cummins are specifying they use “tap water”.
Page 14 point 1.
https://www.cummins.com/sites/default/files/2021-08/cummins-hydrogen-generation-brochure-20210603.pdf
Do you know what you get when you burn hydrogen?
Probably not.
NOx and water vapor. If the hydrogen is not burned correctly, you get more NOx from burning it than you do burning natural gas.
https://www.thechemicalengineer.com/features/hydrogen-the-burning-question/
Luckily fuel cells don’t burn hydrogen.
You need electrolytes (salt) to electrolyze water. Might as well use sea water.
There are plenty of other problems with hydrogen energy, though.
This is not correct. All commercial electrolyzers need very pure water as a feed to the system. PEM and SOEC electrolyzers use the ultrapure (industry term) water directly, while alkaline electrolyzers combine it with potassium hydroxide. Using sea water will very quickly result in non-functional equipment.
I wouldn't be too concerned about that. Annual hydrogen production is around 120 billion kg per year, which corresponds to about 1.08 trillion liters of water. We use about 4 quadrillion liters of fresh water total each year.