Re:Photocatalyst splits water into H and O2 at quantum effic...
by m4rtink on Saturday December 26, 2020 @03:57PM
(#25546412)
Hydrogen is also notoriously low density, even in liquid form. It embritles metals on contact. Hydrogen fires are invisible during the day (if you see rocket engineers walking around with broom pointed forward in front of them, that's why).
Personally I count on hydrogen for high energy space propulsion (either chemical with oxygen or alone in a NERVA for NTR) as otherwise it's IMHO too much of a headache to work with in practice.
And it won't be. H2 is terrible for convenience of handling compared to gasoline. Handling liquid H2 is a nonstarter, it liquefies at 21 K at atmospheric pressure; cryogenics like that are not convenient at all. Gaseous H2 will escape through every tiny gap in whatever containment setup you choose, plus it's highly flammable, much easier to ignite inadvertently than gasoline.
And to top it all off, at the end of the day, its available chemical energy per unit mass is only two to three times that of liquid hydrocarbons. That's simply not enough of an advantage to overcome all the downsides.
What H2 can be used for is to make liquid hydrocarbons, through various chemical processes.