For in an evaporator as long as it's dry any wood is good, it's not like in the house where you add wood and want it to last for hours. With all pine you might just end up fueling a minute or 2 sooner than with hardwoods, but being you should not burn it in the house, this is a good place to use it up.
Dave Klish, I recently ordered a 2x6 wood fired evaporator from A&A Sheet Metal which I will be converting to oil fired
Now have solar, 2x6 finish pan, 5 bank 7x7 filter press, large water jacketed bottler, and tankless water heater.
Recently bought another Gingerich RO, this one was a 125, but a second membrane was added thus is a 250, like I had.
After running a 2x3, a 2x6, 3x8 tapping from 79 taps up to 1320 all woodfired, now I'm going to a 2x6 oil fired and a 200-425 taps.