So a model T was about 50 octane in the day. But bad gas, is bad gas. I don't know what this stuff breaks down to these days. Additives and what we add...
I'd burn it off in a hit/miss engine as 40 was good and once it's hot it'd burn some serious junk stuff... maybe saw some wood... or you got a fence line weed problem? I have a well so I'll very careful of the earth, as I was without a well.
https://www.youtube.com/watch?v=YsVnPdRjCU4
Best I can say is find a place that'll take it. Maybe the oil guys.