System for recycling plastics

Abstract

One embodiment of a method of recycling a plastic material includes heating a plastic material in a treatment chamber in incremental steps through a series of graduated temperature set points wherein each graduated temperature set point corresponds to a vaporization temperature of an individual by-product of said plastic material, and pulling a vacuum of inert gas on the treatment chamber at each temperature set point to selectively remove an individual by-product corresponding to the temperature set point.

1 . A method of recycling a plastic material, comprising:
 heating a treatment chamber including a plastic material to a first predetermined temperature;   pulling a vacuum on said treatment chamber to remove a first gaseous product from said plastic material;   heating said treatment chamber to a second predetermined temperature greater than said first predetermined temperature; and   pulling a vacuum on said treatment chamber to remove a second gaseous product from said plastic material.   
     
     
         2 . The method of  claim 1  further comprising maintaining an oxygen level in said treatment chamber below a combustion level of liquid or gaseous products from said plastic material. 
     
     
         3 . The method of  claim 1  wherein said treatment chamber is held at said first predetermined temperature until a sensor detects the presence of said first gaseous product in an exiting stream from said treatment chamber in an amount below a first predetermined amount of said first gaseous product. 
     
     
         4 . The method of  claim 1  wherein said treatment chamber is held at said second predetermined temperature until a sensor detects the presence of said second gaseous product in an exiting stream from said treatment chamber in an amount below a second predetermined amount of said second gaseous product. 
     
     
         5 . The method of  claim 1  wherein said treatment chamber is held at said first predetermined temperature for a time period determined by a control system. 
     
     
         6 . The method of  claim 1  wherein said vacuum is pulled on said treatment chamber utilizing an inert gas. 
     
     
         7 . The method of  claim 1  wherein a finished product of said method comprises petroleum oil. 
     
     
         8 . The method of  claim 7  wherein said petroleum oil is removed in liquid form from a bottom of said treatment chamber. 
     
     
         9 . The method of  claim 1  wherein said first and second gaseous products are sequentially condensed in a condensation tank to sequentially produce separated, liquified first and second by-products. 
     
     
         10 . The method of  claim 1  wherein said first predetermined temperature is less than a boiling point of a highest-boiling-point-contaminant in said plastic material. 
     
     
         11 . The method of  claim 1  wherein said plastic material comprises waste plastic containers including waste milk jugs and waste soda bottles. 
     
     
         12 . The method of  claim 1  wherein said first predetermined temperature is in a range of 270 to 330 degrees Celsius and said first gaseous product comprises vaporized hydrochloric acid, and said second predetermined temperature is in a range of 300 to 375 degrees Celsius and said second gaseous product comprises vaporized bromine. 
     
     
         13 . A system for recycling plastic material, comprising:
 a treatment chamber for receiving plastic material therein;   a heating system that heats said treatment chamber;   a vacuum system that pulls a vacuum on said treatment chamber utilizing an inert gas; and   a control system including computer operable instructions that control said heating system to heat said treatment chamber in incremental steps through a series of graduated temperature set points.   
     
     
         14 . The system of  claim 13  further comprising a sensing system that detects an amount of a plurality of gaseous products pulled by said vacuum system from said treatment chamber, wherein said control system automatically controls said heating system based on information received by said control system from said sensing system. 
     
     
         15 . The system of  claim 14  wherein said sensing system detects when an amount of a first gaseous product pulled by said vacuum system from said treatment chamber falls below a predetermined first value, and wherein said control system thereafter controls said heating system to heat said treatment chamber from a first predetermined temperature to a second predetermined temperature. 
     
     
         16 . The system of  claim 15  wherein said sensing system detects when an amount of a second gaseous product pulled by said vacuum system from said treatment chamber falls below a predetermined second value, and wherein said control system thereafter controls said heating system to heat said treatment chamber from said second predetermined temperature to a third predetermined temperature. 
     
     
         17 . The system of  claim 13  wherein said heating system comprises a gas manifold that heats ambient air and a duct system that circulates said heated ambient air around said treatment chamber. 
     
     
         18 . The system of  claim 13  further comprising a vapor treatment vessel connected to said treatment chamber, said vapor treatment vessel including a vapor exit port and a liquid exit port. 
     
     
         19 . The system of  claim 18  further including a scrubber connected to said vapor exit port of said vapor treatment vessel. 
     
     
         20 . A method of recycling a plastic material, comprising:
 heating a plastic material in a treatment chamber in incremental steps through a series of graduated temperature set points wherein each graduated temperature set point corresponds to a vaporization temperature of an individual by-product of said plastic material; and   pulling a vacuum of inert gas on said treatment chamber at each temperature set point to selectively remove an individual by-product corresponding to said temperature set point.