Process for the recovery of polymers from mixed plastic waste

A process for the recovery of polymers from mixed plastic waste, said process comprising the following steps:

• a) shredding mixed plastic waste to a predetermined particle size followed by mixing with water and separating a floating top layer of light material containing light plastic and a settled bottom layer of heavy material containing heavy plastic;
• b) separately drying said light material containing light plastic and said heavy material containing heavy plastic in a dryer to obtain a dried light plastic and a dried heavy plastic;
• c) sequentially separating polymers selected from polystyrene (PS), polyvinyl chloride (PVC), ethyl vinyl alcohol (EVOH), nylon, polycarbonate (PC) and polyethylene terephthalate (PET) from said dried heavy plastic by:
• I. mixing said dried heavy plastic in a first fluid medium capable of solubilizing polystyrene under stirring at a first predetermined temperature to obtain a first crude mixture followed by separating said first crude mixture to obtain a first filtrate and first solids containing undissolved plastic material;
• and subjecting said first filtrate to a predetermined method to obtain polystyrene and said first fluid medium, wherein said first predetermined temperature is in the range of 30° C. to 50° C.;
• II. mixing said first solids in a second fluid medium capable of solubilizing polyvinyl chloride under stirring at a second predetermined temperature to obtain a second crude mixture followed by separating said second crude mixture to obtain a second filtrate and second solids containing undissolved plastic material;
• and subjecting said second filtrate to a predetermined method to obtain polyvinyl chloride and said second fluid medium, wherein said second predetermined temperature is in the range of 40° C. to 60° C.;
• III. mixing said second solids in a third fluid medium capable of solubilizing ethyl vinyl alcohol (EVOH) under stirring at a third predetermined temperature to obtain a third crude mixture followed by separating said third crude mixture to obtain a third filtrate and third solids containing undissolved plastic material;
• and subjecting said third filtrate to a predetermined method to obtain ethyl vinyl alcohol (EVOH) and said third fluid medium, wherein said third predetermined temperature is in the range of 60° C. to 80° C.;
• IV. mixing said third solids in a fourth fluid medium capable of solubilizing nylon under stirring at a fourth predetermined temperature to obtain a fourth crude mixture followed by separating said fourth crude mixture to obtain a fourth filtrate and fourth solids containing undissolved plastic material;
• and subjecting said fourth filtrate to a predetermined method to obtain nylon and said fourth fluid medium, wherein said fourth predetermined temperature is in the range of 90° C. to 110° C.;
• V. mixing said fourth solids in a fifth fluid medium capable of solubilizing polycarbonate (PC) under stirring at a fifth predetermined temperature to obtain a fifth crude mixture followed by separating said fifth crude mixture to obtain a fifth filtrate and fifth solids containing undissolved plastic material;
• and subjecting said fifth filtrate to a predetermined method to obtain polycarbonate (PC) and said fifth fluid medium, wherein said fifth predetermined temperature is in the range of 110° C. to 130° C.;
• and
• VI. mixing said fifth solids in a sixth fluid medium capable of solubilizing polyethylene terephthalate (PET) under stirring at a sixth predetermined temperature to obtain a sixth crude mixture followed by separating said sixth crude mixture to obtain a sixth filtrate and sixth solids containing residual plastic material;
• and subjecting said sixth filtrate to a predetermined method to obtain polyethylene terephthalate (PET) and said sixth fluid medium, wherein said sixth predetermined temperature is in the range of 140° C. to 160° C.;
• and
• d) sequentially separating polymers selected from polypropylene (PP), high density polyethylene (HDPE), low density polyethylene (LDPE) from said dried light plastic by solubilizing said dried light plastic in a seventh fluid medium under stirring at a seventh predetermined temperature to obtain a seventh crude mixture, wherein said seventh predetermined temperature is in the range of 110° C. to 130° C. followed by:
• I. cooling said seventh crude mixture to a temperature in the range of 110° C. to 120° C. followed by filtering to obtain polypropylene and a seventh filtrate;
• II. cooling said seventh filtrate to a temperature in the range of 90° C. to 100° C. followed by filtering to obtain high density polyethylene and an eighth filtrate;
• and
• III. cooling said eighth filtrate to a temperature in the range of 75° C. to 85° C. followed by filtering to obtain low density polyethylene and said seventh fluid medium;
• and
• wherein said predetermined method is selected from the group consisting of cooling, adding an antisolvent, distillation, centrifugation, skimming, and settling and filtration.