A new process for separating a mixture of incompatible polymers, such as polyethyleneterephthalate (PET) and polyvinyl chloride (PVC), promises to expand the recyclingand reuse of plastic waste. The first commercial plant, at Celanese"s recycling facility in Spartanburg, S.C., has been operating since February at a PET capacity of15 million lb/yr. Operating cost: 0.5¢/lb.
Targeted to replace the conventional sorting of individual PET bottles from PVC containers upstream of the recycling step, this process first chops the mixed waste withrotary-blade cutter to 0.5-in. chips. The materials are then suspended in water, and air is forced through to create a bubble-like froth that preferentially entraps the PVC because of its different surface-tension characteristics. A food-gradesurfactant is also added to enhance the separation. The froth is skimmed away along with the PVC, leaving behind the PET material. For a feed with 2% PVC, the process has recovered almost pure PETwith an acceptable PVC contamination level of 10 ppm.
How many lb of PVC are recovered per year from the above cited process?