.... around my areas we have collection centers, or recycling places all over the county. They have a tank, inside a shed, where folks can bring and dump their motor oil. If I have only a small amount of antifreeze I just pour it in my 10 gal used oil jug with the used oil.
If you ask anyone I'll bet you that you will end up PAYING someone to take it....thats the way it works. Don't ask....
When the old oil is distilled recycled or "cooked" they have ways of dealing with the "burn off" gases ect... but don't ask!!!!