+1
Can't recycle the resins, carbon is carbon so why burn off the resins to get carbon again..... and its two of the most inert things known to man combined into a tube so I'd chuck it and feel fine about the environment
Unless there is a carbon bike repairer who may benefit from sections to use in repairing frames, if your bike is common and worth $$?
Well, WAS worth $$$

and he may like the bits