If latent heat is the trick for moving heat then is there a trick to using the heat in an engine?
Google:"influence of dissociation of gas on Brayton Cycle performance."
The following said thermal efficiency of gas went to 160% optimum.
http://www.dtic.mil/cgi-bin/GetTRDoc?AD=AD274222&Location=U2&doc=GetTRDoc.pdf (http://www.dtic.mil/cgi-bin/GetTRDoc?AD=AD274222&Location=U2&doc=GetTRDoc.pdf)
Might as well take a look at Dinitrogen_tetroxide, it is one of those gasses. It could also be made from air, water, electricity. The space program wouldn't have been the same with out it. (Maybe more interresting)http://en.wikipedia.org/wiki/Dinitrogen_tetroxide (http://en.wikipedia.org/wiki/Dinitrogen_tetroxide)
Re: The following said thermal efficiency of gas went to 160% optimum.
The link has moved. It's now at: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19800008230.pdf
From the abstract: "Compared with data for helium as the working fluid, these results indicate efficiency improvements from 4 to 90 percent, depending on turbine inlet temperature, pressures, and gas residence time in heat-transfer equipment."
That's an increase in efficiency from 4-90%, which is pretty amazing! However, the article spends most of the time discussion on super-high temps, as in a nuclear reactor.
But as noted on pg. 7: "As pointed out in the section LITERATURE REVIEW, the reacting gas N204 is also an attractive working fluid in a condensing cycle. It has a saturation line such that condensing temperatures between 700 and 900 F correspond to pressures between 1.0 and 1.6 atmospheres."
So this is probably of more use to this forum.
See also the Wikipedia article https://en.wikipedia.org/wiki/Dinitrogen_tetroxide#Power_generation_using_N2O4.