I am sorry to say that Birch is absolutely no good for turning whatsoever, but if you want to send it it me, I will dispose of it for you FOC.
Seriously, I have never turned Birch myself, but it is often sold as a turnery wood, so should be fine. As it was free, why not have a go - what have you got to lose?
I managed to pick up a log (only just though) from a tree that was felled to make way for a pylon. Poor exchange I reckon but I took advantage of it. Only tried a couple of small bits so far and I thought it was nice and well behaved to turn and was also quite stable with not as much movement as I expected.