Recovery of styrene from waste polystyrene
AssigneeBASF SE
InventorAndreas Northemann
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Abstract
Monomeric styrene is recovered from plastics waste containing styrene polymers by thermal depolymerization by a process in which the waste is transported in liquid or solid form into a fluidized bed of a solid heat transfer agent and is cracked or depolymerized in an average residence time of less than 60 seconds and styrene is obtained from the gaseous crack products. Preferably, magnesium aluminum silicate is used as a heat transfer agent and C.sub.1 -C.sub.6 -hydrocarbons formed as byproducts in the depolymerization are used as operating gas for maintaining the fluidized bed and are circulated.
Claims4
A process for recovering monomeric styrene from plastics waste containing styrene polymers by thermal depolymerization, wherein the waste in liquid or solid form is transported into a fluidized bed of magnesium aluminum silicate heated to 400.degree.-700.degree. C. and is cracked or depolymerized in an average residence time of less than 60 seconds and styrene is recovered from the gaseous crack products.
Dependencies are inferred from the claim text.