Hydrogen fuel questions

[CosmicGamer]

These questions were overlooked in the other thread so I'll start a new one.

What little physics and chemistry I know is decades old and long forgotten from lack of use. I also own a very limited set of CT material which is also decades old and mostly long forgotten.

1) Is it correct that the preferred form of hydrogen fuel in Traveller is in the form of liquid hydrogen?

2) There are references in Traveller to using unrefined fuel. What exactly does this mean?
2a) Is it still liquid hydrogen but not pure?
2b) Could it be water going straight into the power plant and drives?
2c) If a ship scoops the gasses from a gas giant and stores it in gaseous state can it be put straight into the power plant and drives as unrefined fuel?

3) There was discussion of the amount of hydrogen in water and liquid hydrogen. What about hydrogen skimmed from the gas giant? It needs to be stored while being processed. What's it's density?

4) What are the properties of hydrogen under various temperatures?

When water gets cold enough, it freezes. When it freezes, it expands. When heated, it also would build up pressure as it tries to expand into a gas.
5) How would these pressures compare to those of hydrogen and compare the storage issues of both under a variety of temperatures.

 

[steventirey1985]

1) Classic Traveller Book 2 only mentions (as far as I can tell) refined and unrefined fuel. No mention of what it actually is besides unrefined fuel can be skimmed from gas giants. Book 5 does say fuel is liquid hydrogen.

2a) Possibly.
2b) Also possbile.
2c) Book 5 does say a fuel purification plant is needed to use the unrefined fuel from a gas giant. (page 21) Page 27, however, says unrefined fuel can be used before purification, but can result in malfunctions and misjumps.

And I have no clue as to the rest.

 

[aramis]

Gas Giant atmosphere is mostly Hydrogen, Helium, Methane and Ammonia.

H2 is roughly 14 kL per ton. Density is about 0.071 to 0.0763, 1/1 hydrogen, for 14.085kl to 13.11 kL per ton; this says its stored close to but below boiling point.

Water is roughly 1 kL per ton, and 1/9 hydrogen, for 9kL per ton of hydrogen, and 9 tons mass per ton of hydrogen.

Ammonia, NH3, is 3/17 hydrogen, density 0.6819, for partial density of hydrogen of 0.12, thus 1 ton of Hydrogen as Ammonia is 8.3 tons mass and roughly 12.2 kL

Methane, CH4, is 4/16 hydrogen, has a density of about 0.416, and thus a partial density of about 0.101 of hydrogen. A ton of hydrogen as methane is thus about 9.9 kL, and 39.6 tons.

 

[fusor]

Gas Giant atmosphere is mostly Hydrogen, Helium, Methane and Ammonia.

In our solar system, the Large Gas Giant atmospheres (Jupiter and Saturn) are composed almost entirely of hydrogen and helium. Methane and Ammonia are present in relatively tiny amounts (actually they're measured in parts per million). It's enough to colour clouds and so on, but not enough to make a big compositional difference. That said, the clouds are made of methane and ammonia and so those locally concentrate those gases, so I guess if you want to scoop those up then you'll want to aim for the clouds rather than just scooping up the hydrogen/helium 'air'.

Uranus' and Neptune's atmospheres are also mostly hydrogen and helium, but they have more methane (of the order of 1-3%). Ammonia barely shows up at all there.

See the relevant planet's info sheet on http://nssdc.gsfc.nasa.gov/planetary/planetfact.html for full breakdown.


Elsewhere, there may be other complications. While all gas giants are predominantly hydrogen and helium, and 'cold' gas giants like the ones we have are probably similar to what I described above, it's entirely possible for Hot Jupiters to have clouds of silicate and iron; essentially, instead of flying through clouds of water or methane vapor (which won't be present because of the temperature), you'd be flying through clouds of molten rock vapor!

 

[aramis]

Fusor, any GG in a CT/MT/TNE/T4 extended system generation is going to be outside the ecosphere, and thus pretty much a "cold" one. The 5 relevant gasses are Hydrogen, Helium, Neon, Ammonia, and Methane.

Since these are also the most readily available sources of hydrogen... both from GG's and outer system moon surfaces...

 

[McPerth]

Fusor, any GG in a CT/MT/TNE/T4 extended system generation is going to be outside the ecosphere, and thus pretty much a "cold" one. The 5 relevant gasses are Hydrogen, Helium, Neon, Ammonia, and Methane.

Since these are also the most readily available sources of hydrogen... both from GG's and outer system moon surfaces...

IIRC (I cannot check it now), GG may also be in the ecosphere, the main world being a satellite of them.

 

[aramis]

IIRC (I cannot check it now), GG may also be in the ecosphere, the main world being a satellite of them.

It's actually possible in rare cases to force a GG into the inner system, but I've never actually rolled one such system; I've never had the needed rolls collide...

 

[fusor]

Fusor, any GG in a CT/MT/TNE/T4 extended system generation is going to be outside the ecosphere, and thus pretty much a "cold" one. The 5 relevant gasses are Hydrogen, Helium, Neon, Ammonia, and Methane.

I was largely responding to correct your statement about gas giant atmosphere composition, which is nothing to do with which Traveller RPG rules are being used.

As I pointed out, the only "relevant gases" are Hydrogen, Methane and Ammonia. Helium isn't used, Neon is irrelevant and present in miniscule amounts, if at all (did you actually look at the link I posted?), and Ammonia and Methane are in the 1-3% range at most, in small gas giants and barely there in larger ones. And you won't have ammonia in the habitable zone either. See http://en.wikipedia.org/wiki/Sudarsky_extrasolar_planet_classification for further info on gas giant compositions.

Also, I thought that in the CT system you can have GGs in the inner zone or habitable zone, if there aren't enough orbits remaining elsewhere in the system?

Since these are also the most readily available sources of hydrogen... both from GG's and outer system moon surfaces...

Of course, you can save your ship a lot of structural and heat stress/damage by just landing on an icy moon and mining ice from there.

And there's also the matter of whether a gas giant is nearby when the ship emerges from jump and wants to refuel anyway.

 

[aramis]

Also, I thought that in the CT system you can have GGs in the inner zone or habitable zone, if there aren't enough orbits remaining elsewhere in the system?

That's so rare as to be a GM-Fiat situation.