On 27May2023 0929, David Shaw - tihnessa at gmail.com (via tml list) wrote:
> You saying that reminds me - I'm pretty sure I remember someone on the
> list saying once that doing exactly that, using water, actually gave you
> more hydrogen per unit volume than using l-hyd so, if someone can
> confirm my memory, you'd be absolutely right.

A displacement ton holds 1 tonne of liquid hydrogen.

A displacement ton holds 14 tonnes of water. Water is made up of one
oxygen atom (mass ~16) and two hydrogen atoms (mass ~1), so the mass of
a molecule of water is ~18, and of that ~2 is hydrogen, or 1/9th.
Therefore a displacement ton of water contains 14/9 = 1.556 tonnes of
hydrogen.

So water is a more volume efficient way of storing hydrogen than liquid
H2 is. It's very mass inefficient, however.

--
Rupert Boleyn <xxxxxx@gmail.com>