Rolls-Royce Touts Nuclear Reactors as Key to Clean Jet Fuel

Re:Rolls-Royce Touts Nuclear Reactors as Key to Clean Jet Fuel by jemfinch on Friday December 06, 2019 @10:09PM (#21728213)

But a liter of compressed hydrogen weighs 38 grams, while a liter of kerosene weighs 810 grams. So the energy density by gram, rather than liter, is in favor of compressed hydrogen by a factor of more than 5x.

I don't know what the tradeoff is between volume and weight in aviation, but it's worth noting that we can measure density by both volume and weight, and by weight compressed hydrogen defeats kerosene.

[ Parent | on HN ]

Re:Rolls-Royce Touts Nuclear Reactors as Key to Clean Jet Fuel by evgen on Saturday December 07, 2019 @03:59AM (#21729236)

If you are going to compare hydrogen and kerosene by weight you need to include the weight of the containment vessel. For kerosene that is a thin piece of aluminum. For hydrogen it is...not.

[ Parent | on HN ]

Re:Rolls-Royce Touts Nuclear Reactors as Key to Clean Jet Fuel by godelski on Friday December 06, 2019 @11:17PM (#21728438)

In aviation weight is more important. Volume is important, but weight (and distribution) is more important.

[ Parent | on HN ]

Re:Rolls-Royce Touts Nuclear Reactors as Key to Clean Jet Fuel by dr_dshiv on Saturday December 07, 2019 @06:31AM (#21729714)

So, for sleek jets, heavy but compact jetfuel will rule. But for zeppelins, the weight-to energy ratio is much more important, as they have plenty of volume to spare..

[ Parent | on HN ]

Re:Rolls-Royce Touts Nuclear Reactors as Key to Clean Jet Fuel by loeg on Friday December 06, 2019 @10:28PM (#21728275)

That's a good point I hadn't considered, thanks.

[ Parent | on HN ]