You can convert it to oil instead of burning(which releases dioxins/heavy metals and other chemicals).
http://www.plastic2oil.com
https://www.instructables.com/id/Waste-Plastic-to-Fuel/
https://permaculturenews.org/2014/03/21/home-scale-conversio...
https://plastics.americanchemistry.com/Plastics-to-Oil/
https://www.sciencealert.com/holy-crap-watch-this-guy-turn-p...