Water is injected into a valved chamber similar to fuel injection in an internal combustion engine. Instead of a spark, the reaction is provided by a quantity of potassium simultaneously supplied.

The energy released from the engine heats the water enough to turn it to steam, which is directed to propel the vessel.
-- sprogga, Oct 19 2007

Let's not allow reality to get in the way of a good story http://www.chemguid...roup1/reacth2o.html
explanation of reactions of group 1 elements with water, with a few surprising realities. All rather counter-intuitive, really. [Custardguts, Oct 21 2007]

You forgot to say what to do with the waste products from your engine.
-- lurch, Oct 19 2007


//You forgot to say what to do with the waste products from your engine//
Whilst I agree with your sentiments, [lurch], I don't think Messrs Watt, Benz, Diesel or Whittle considered the question either.

[EDIT] Why potassium?
Why not sodium or lithium? The reaction would be more violent (== energetic) for less "fuel" mass, no?
-- AbsintheWithoutLeave, Oct 19 2007


Or bananas? Unlike diesel or sodium, you could eat the fuel.

Although I think you could still eat lithium. I read somewhere it is good for you. Makes you feel better.
-- mylodon, Oct 19 2007


<Homer> Mmmmmm...lithium. </Homer>
-- zen_tom, Oct 19 2007


would this be upgradeable to a cesium engine? I really like to go fast myself.
-- jhomrighaus, Oct 19 2007


Awwlright you lousy steam you, look alive and give this 'ere boat a bittuv a shove....
-- the dog's breakfast, Oct 19 2007


//Why not sodium or lithium? The reaction would be more violent (== energetic) for less "fuel" mass, no?// No, the opposite. Lithium is less reactive than sodium, which is less reactive than potassium, which is (as jhomrighaus points out) less reactive than caesium.

The waste product, potassium hydroxide, could help to counter the effects of acid rain.
-- MaxwellBuchanan, Oct 19 2007


[MB] Thanks for that - it is over 30 years since I was intimately acquainted with the periodic table.
-- AbsintheWithoutLeave, Oct 19 2007


So does this work like the baking soda and vinegar volcano?
-- Jscotty, Oct 19 2007


lutefisk (from lutfisk, "lye fish"). Cod is soaked in Potassium Hydroxide or (KOH) to a jelly-like consistency, then served with bacon fat, potatoes, brown cheese (brunost) sauce and mushy peas.

So...it's like a good start then?
-- 2 fries shy of a happy meal, Oct 19 2007


//Cod is soaked in Potassium Hydroxide or (KOH) to a jelly-like consistency, then served with bacon fat, potatoes, brown cheese (brunost) sauce and mushy peas. //
Good job it isn't served with chips - you could be tempted to put vinegar on it!
-- AbsintheWithoutLeave, Oct 19 2007


No no, I think [Absinthe] might have been onto something there. Whilst Potassium is more energetic per mole, on a per gram basis, I think sodium or Lithium would probably tip the scale.

.... Check [linky] actually lithium is more energetic, per mole even. Hmmm. Super-fuel, anyone?

Given that Lithium is 6.9 g/mol and Potassium is 39.1g/mol, we have ourselves a clear weiner.

Potassium as a fuel is worth 5.01 kJ/mol

and Lithium races by at 32 kJ/mol.

Well spank my arse and call me charly. I wouldn't have thought it would be so disparate.
-- Custardguts, Oct 21 2007


Yeah, but you'd only eat cod soaked in lithium if you were crazy.
-- lurch, Oct 21 2007


summer break meets chemistry class meets autoshop.
-- 4whom, Oct 22 2007


Yeah, lithium seems to outstrip potassium. Plus, lithium is lighter.
-- Shadow Phoenix, Oct 22 2007


You could use the potassium hydroxide to make biodiesel.
-- nineteenthly, Oct 22 2007


with sodium, lithium, and caesium, the off-gassed hydrogen actually auto-ignites because the reaction is so hot, so you'd really be making a rocket engine

with caesium, the reaction is so violent it's a huge explosion
-- EdwinBakery, Dec 07 2012


Either/any reactive metal is going to cost you more to make than you'll get out of it pushing a boat. Lithium may work as an energy-storage scheme, but as a power source, it's crazy talk.
-- baconbrain, Dec 07 2012


Potasium is purified with electrical current. How many Kilowatts of energy is required to purify enough potassium to create a kilowatt internal-combustion power?

Not looking too beneficial to me. Maybe it would be useful for a torpedo engine or something.
-- Kansan101, Dec 07 2012



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