How about the 6% sulfur contained in the rubber?
It is oxidized to SO2 which, when it cools with the water vapor in the exhaust stream, produces a goodly amount of sulfuric acid.
The gubmint has forced refineries to spend beaucoup amount of dollars to eliminate a much lower sulfur content in their product.
But then, double standards mean nothing to the likes of Hitlery.
With excellent temparature control, flow rate and the right chemical scrubbers we can get that SO2 out. You're burning tires -- the fuel chemical and heat content mix is very stable. You can deign the burner and exhaust cleansing very efficiently.
"It is oxidized to SO2 which, when it cools with the water vapor in the exhaust stream, produces a goodly amount of sulfuric acid."
Yet if the tires are introduced into the fuel stream of a coal burning plant, there is a good chance that there is a SO2 scrubber downstream.