You need to first separate heavy water from normal water using the
heavy water extractor. You can then pass the heavy water in to the electrolyzer and produce two units of deuterium and one unit of oxygen. It's a very slow process. Note that heavy water is
not the same thing as regular water.
I don't believe that would work. We know Reika has gone to great lengths to simulate realistic engineering principles in this mod.
Let's look at the first law of thermal dynamics, "The increase in internal energy of a closed system is equal to the heat supplied to the system minus work done by it."
This tells us that temperature does not increase on a linear scale; two bodies in space of a given temperature do no combine their temperature (their energy state) to increase their temperature equivalent to the sum of their previous energy state. If anything, without another source of heat to supply energy to the system, their combined heat will see a net reduction in the energy state of the body with the higher temperature, cooling it off, like dousing red hot iron bars in a pool of water; entropy.
That is to say, if lava has, for example, a constant temperature of 600C, it will heat a blast furnace until the two are in a state of thermal equilibrium, which in RoC terms (an idealized closed system) means that they will be the same temperature after enough time has passed.
If you place a friction heater on the same furnace and give it enough power to heat the furnace to, say, 1000C, you won't get 1000C+600C=1600C because adding heat (energy) is not the union of two quantities, like, for example, adding two glasses of water would be. What we've done is supplied more heat (ie: we've increased the energy potential of the furnace) which causes the temperature to increase in proportion to the energy being supplied.
You'll get exactly and precisely 1000C because the input energy from the friction heater supersedes that of the lava. Effectively, if they two were connected and not insulated from each other (which we can infer that they are not since we use lava as an early, abundant heat source), then realistically, along with the furnace, we would also heat the lava up to or approaching 1000C as it absorbs heat energy from the furnace next to, which in turn is being heated by a source that is hotter than both of them, until all three objects reach a state of thermal equilibrium (equal to the heat energy of the friction heater, the source).
This isn't modeled in RoC, however, so don't go looking for evidence of this. I'm just saying that, realistically, this is what would happen in an idealized closed system (up to the boiling point of lave, at any rate - and we haven't even begun to consider entropy beyond mentioning it briefly).
tl;dr I doubt very much that
@Reika intends me to pre-heat the pulse jet furnace with a lesser heat source than the one it's being supplied with in order two squeeze out that last 28C that I need to make this work.