oxygen and combustible material do not go well together for safety.
Especially hydrocarbon fractions heated to ~300F or ~400F. Mother of All Bombs. I believe it's the primary reason why they use a nitrogen purge, and why the oxygen sensors (65 of them?) are so critical.
It's another reason why you don't want some minimum wage fork lift driver monitoring the process.
"Give me your tires, your plastic,
Your 20 ton masses yearning to be cracked,
The wretched refuse of your 7-Eleven stores.
Send these, the oxygenless, trashcan-tost to me,
I lift my secret catalyst beside the P2O feedbin door!"