What you are describing could be the starting point for a processing plant that mimicks a digestive system. Plastics are moved via peristalsis through a series

What you are describing could be the starting point for a processing plant that mimicks a digestive system. Plastics are moved via peristalsis through a series of physical and chemical incubators, extracting elemental substances through membranes along the way. Out comes the unusable, uhm, ash, that needs to be discarded.