Xenobiology Speculation/Question

[Slacker]

Want to run something past the folks who are more inherently hard science than I am. I'm utilizing a star system generation problem (Astrosynthesis 3, specifically, with some GURPS mods built in for extra detail) and the thing has spit out a number of Ammonia/Methane worlds with a significant population.

Is this a viable chemical basis for life? I know that ammonia is generally considered a pretty good replacement for water in a biology, and that in theory methane based respiration works too. But is there a plausible biology by which a ecology could evolve where ammonia is used as a solvent, like water, and methane for respiration replacing oxygen? I know it would be at a temperature below Earth norm, and the planet would look something like a warm Titan. I was thinking something involving respiration stripping the hydrogen atoms off of the methane and utilizing them for energy along with some kind of ammonia reaction, but this is where my relatively limited chemistry knowledge hits a wall that Google isn't helping me solve. I've found plenty speculation involving ammonia based biology and methane based biology, but not a biology that incorporates the two.

Help?

[Broomstick]

The first thing I would do is check out the terrestrial extremophiles for those associated with methane and ammonia, preferably those likely cold environments. The downside to that is that our extremophiles don't use ammonia as a solvent, they use it as food. I'm sure there has been some scholarly speculation on possible Titan life out there as well.

[Slacker]

Yeah, I think my problem is I'm trying to combine two things that individually have had some speculation, but combined not so much. Most exobiology/extremophile speculation/science has one or the other, not both.