I was recently at a shop that repairs small engines. Many of the problems he runs into are caused by bad gas. So as a rule, he drains any gas that comes in and sends the engine back out with a full tank of fresh gas. However, he doesn't have a good way to get rid of the old, contaminated gas. His current solution is to let it evaporate away. He can get rid of about a gallon that way, but it really seems like (a) a shitty solution and (b) a waste of burnable fuel. So what ideas can I give this guy to dispose of his old gas? It's not suitable for running an engine, but it seems like it could be used for some form of heat. Any ideas?