Tripropelant Fuel Idea.

[Titan Space Agency]

Hey, I have been messing around with this program called "go reacthttp://www.msichicago.org/online-science/games-and-apps/" that allows you to burn elements to create compounds. I found out about the compound called potassium hydroxide. Here are the advantages that I have found by using this. (fuels used are hydrogen, potassium, and oxygen. Forgot to mention)

1. The exhaust (potassium hydroxide) has about the same molar mass as carbon dioxide.

2. Wile you have to melt the potassium (to store in the fuel tanks) potassium has a melting point of only 63.5 degrees C. That's just over half of waters boiling point.

3. From what I know reactions that involve 3 elements are more reactive.

5. It only requires one of each of the 3 atoms needed for the fuels to combust.

Disadvantages.

1. You have to put this 63.5*C fuel next to cryogenic fuels that are below -180*C. Though this could simply be solved through some insulation.

2 .The exhaust is harmful.

3. You HAVE to have the hydrogen as an atom, you can't have it as h2, it wont combust that way.

Tell me what you think of this idea as I come up (Or see in the replies) any more good advantages/disadvantages for this idea I will add on to the thread.

(I hope to be able to use this as a fuel someday)

[DaveofDefeat]

Google says potassium hydroxide makes soap.

[Sauron]

Tripropellant fuels have been studied. There are a lot of pretty bold claims about their impact. Essentially, you can either 'stage' a single stage rocket by switching between different fuels mid-flight or mix 3 propellant streams (this has produced a truly insane isp of 542 s. using lithium, fluorine, and hydrogen). The disadvantage is the extremely complicated engineering. And often dealing with some pretty scary compounds. Fluorine in rockets? Really, really bad idea.

Your combination specifically? Probably not ideal bearing in mind that LOX/H2 is the gold standard of (sane) rocket propellants in terms of isp (but using H2 carries some problems--massive (read: heavy) tanks compared to, say, a fuel like kerosene). Doing better than that requires something more reactive, generally. Like fluorine. Again, that's a seriously bad idea (But maybe fluorine is like vitamins to kerbals? Of course they'd eat the most reactive element... )

[Titan Space Agency]

Yes they use it to make soap

[lajoswinkler]

Potassium hydroxide is very similar to sodium hydroxide, and that's lye. It's a very corrosive alkali.

I'd be interested to see how would these three elements be stuffed together in a reaction chamber. Seems as a huge technological problem. Potassium is a low melting point alkali metal and O2 and H2 are gases.

[Titan Space Agency]

Ya, it would be interesting. I wonder if anyone else had my idea first -.- They could be planing to use it before MEEEEEEEE!!!!!!!!!!!!!!

[DaveofDefeat]

Also, I'm pretty sure Hydrogen cant exist as a single atom, is has to be molecular hydrogen...

[JMBuilder]

Here's something slightly off-topic: Take something like H2 and O2, keeping them separate. Superheat them with a nuclear reactor, ionize them to magnetically accelerate them, then combust them in a nozzle. I don't know if it would be very efficient, but you'd have a NERVA, an ion engine and a regular rocket all in one.

[lajoswinkler]

Hydrogen doesn't have to be in an atomic state to burn, but it can exist at high temperatures as monoatomic.

The whole idea with potassium seems too wild, though.

[magnemoe]

Here's something slightly off-topic: Take something like H2 and O2, keeping them separate. Superheat them with a nuclear reactor, ionize them to magnetically accelerate them, then combust them in a nozzle. I don't know if it would be very efficient, but you'd have a NERVA, an ion engine and a regular rocket all in one.

The idea to add oxygen to the hydrogen after heating in an nerva engine has been thought off. Benefit is increased trust, but lower ISP as the water you get moves slower than the hydrogen and you have to carry the heavy oxygen. Worthwhile if you either mine water or you need the extra trust in the start.

[dharak1]

Tripropellant sounds crazy, probably very few things that can do it... But has anyone ever found a way to make quadpropellant? Very impractical but why not? Is there any mix that would even benefit from it?

[drakesdoom]

I believe I recall a proposed quad propellant, however the results of the Russians working with tripropellants have scared all sane people off the idea. They sound great on paper but are you going to hold the hose while they fill the tank?

[nuclearpower13]

Its a good propellent. The russians used it to power there torpedos durning the Cold War. But one of the problems with it is very volitle and reactive with iron oxide as was found during the sinking of the Kursk. When one of her torpedos was leaking potassium hydroxide and it mixed with rust in the torpedo tube and combusted.

[Kryten]

That was hydrogen peroxide.

[DerekL1963]

That was hydrogen peroxide.

Which, in it's purer forms, is very nasty stuff indeed. Look how reactive the 5% solution you can buy in the store is.

But, on the topic of the thread; Tripropellants are one of those things that keep being studied because they're such an obvious idea. They've however never (AFAIK) been implemented because the weight and complexity of the extra tankage, pumps, pipes, control systems, etc... eat up most if not all of the theoretical gains. (And real life gains are rarely as large as the theoretical ones.)

[DaveofDefeat]

Which, in it's purer forms, is very nasty stuff indeed. Look how reactive the 5% solution you can buy in the store is.

But, on the topic of the thread; Tripropellants are one of those things that keep being studied because they're such an obvious idea. They've however never (AFAIK) been implemented because the weight and complexity of the extra tankage, pumps, pipes, control systems, etc... eat up most if not all of the theoretical gains. (And real life gains are rarely as large as the theoretical ones.)

And all of the stuff proposed for tripropllents seems to explode with just about everything.

[lajoswinkler]

Its a good propellent. The russians used it to power there torpedos durning the Cold War. But one of the problems with it is very volitle and reactive with iron oxide as was found during the sinking of the Kursk. When one of her torpedos was leaking potassium hydroxide and it mixed with rust in the torpedo tube and combusted.

Alkali hydroxides don't react with iron hydroxide (rust). I don't know the reason behind the Kursk tragedy, but it sure wasn't this.

[Kryten]

It was hydrogen peroxide with zinc fittings, but what really killed it was the combination of oxygen and heat from that reaction with volatile torpedo fuel. Oh, and the fireball from the above not being controlled before becoming intense enough to set off every other torpedo in the compartment.

[DerekL1963]

It was hydrogen peroxide with zinc fittings, but what really killed it was the combination of oxygen and heat from that reaction with volatile torpedo fuel. Oh, and the fireball from the above not being controlled before becoming intense enough to set off every other torpedo in the compartment.

Having been in a submarine torpedo room (underway, mumble feet under the North Atlantic), it's not at all clear they can be held at fault for not controlling the fireball. We don't really know how big the initial reaction was, how it manifested, how fast it spread, etc... etc... Witness the loss of USS Bonefish (SS-582) where a minor leak went from undetected to a disaster in only a few minutes.

[Kryten]

I'm not trying to blame anybody, sorry if I give that impression. Given how intense the fire would have to be to heat the room evenly enough to get the kind of simultaneous detonation there apparently was, I'm not sure it'd be controllable except under pretty much perfect conditions, never mind mind the ones you could expect on an operational submarine.

[rhoark]

To give an idea of how difficult fluorine is to work with, its hypergolic with hydrogen, methane, water, aluminum, graphite, cotton, nylon, teflon, sand, bricks, people, and fire extinguishers.

[Captain Sierra]

And that's why nobody is suicidal enough to use it as rocket propellant!

[lajoswinkler]

Wait, who even said anything about fluorine? It will never be used for propulsion, you can be sure about that.

It is not hypergolic with teflon. It does not react with it because there's nothing to react with in that molecule.

It is also not hypergolic with people. Lowering your hand in a container of fluorine will feel warm and tingly, but it will not catch on fire. It's not the monster of the elements. The fact it reacts with nearly everything doesn't mean the reaction rates are always high.

To my knowledge, only lots of gases, certain liquids and many powdered metals are hypergolic with fluorine at 1 atm.

[Kryten]

And that's why nobody is suicidal enough to use it as rocket propellant!

The Soviets developed a series of Ammonia/Fluorine engines for proton upper stages, but they never flew.

[drakesdoom]

Wait, who even said anything about fluorine? It will never be used for propulsion, you can be sure about that.

Well actually John D. Clark said something about Fluorine.

https://en.wikipedia.org/wiki/Chlorine_trifluoride#Rocket_propellant