Method and Device for Refining Waste Plastic Pyrolysis Oil

Abstract

The present disclosure provides a method and device for refining waste plastic pyrolysis oil, the method including (S1) subjecting a waste plastic pyrolysis oil feedstock to a heat treatment by charging the waste plastic pyrolysis oil feedstock into a rotary kiln reactor and increasing a temperature of the rotary kiln reactor to form a product; (S2) recovering a gas component from the product of step (S1); (S3) separating a high boiling point wax component from the recovered gas component and re-supplying the separated high boiling point wax component to the rotary kiln reactor in step (S1); and (S4) recovering refined oil from the gas component from which the high boiling point wax component is removed.

What is claimed is: 
     
         1 . A method for refining waste plastic pyrolysis oil, the method comprising:
 (S1) subjecting a waste plastic pyrolysis oil feedstock to a heat treatment by charging the waste plastic pyrolysis oil feedstock into a rotary kiln reactor and increasing a temperature of the rotary kiln reactor to form a product;   (S2) recovering a gas component from the product of step (S1);   (S3) separating a high boiling point wax component from the recovered gas component and re-supplying the separated high boiling point wax component to the rotary kiln reactor in step (S1); and   (S4) recovering refined oil from the gas component from which the high boiling point wax component has been removed.   
     
     
         2 . The method of  claim 1 , wherein the waste plastic pyrolysis oil feedstock is liquid pyrolysis oil comprising 10 to 30 wt % of Naphtha, 20 to 30 wt % of KERO, 10 to 30 wt % of LGO, and 30 to 50 wt % of VGO. 
     
     
         3 . The method of  claim 1 , wherein in step (S1), the heat treatment is performed by increasing the temperature of the rotary kiln reactor to a third temperature. 
     
     
         4 . The method of  claim 3 , wherein the third temperature is 400 to 600° C. 
     
     
         5 . The method of  claim 3 , wherein when the temperature of the rotary kiln reactor is increased to the third temperature in step (S1), a temperature increase rate is 0.5° C./min to 5° C./min. 
     
     
         6 . The method of  claim 3 , further comprising, before step (S1):
 (S1-1) subjecting the waste plastic pyrolysis oil feedstock to a first heat treatment by increasing a temperature of the rotary kiln reactor to a first temperature; and   (S1-2) subjecting the waste plastic pyrolysis oil feedstock to a second heat treatment by increasing a temperature of the rotary kiln reactor to a second temperature,   wherein the temperature of the rotary kiln reactor is increased by sequentially heating the rotary kiln reactor from the first temperature to the third temperature.   
     
     
         7 . The method of  claim 6 , wherein the first temperature is 50 to 150° C. 
     
     
         8 . The method of  claim 6 , wherein the second temperature is 220 to 300° C. 
     
     
         9 . The method of  claim 1 , wherein in step (S1), the heat treatment is performed by adding an additive. 
     
     
         10 . The method of  claim 9 , wherein the additive comprises a metal oxide catalyst or a composite catalyst in which an active metal is supported on a metal oxide carrier. 
     
     
         11 . The method of  claim 1 , further comprising, before step (S1), a step (S0) comprising charging waste plastics into a pyrolysis reactor and pyrolyzing the waste plastics at a temperature of 300 to 600° C. in a non-oxidizing atmosphere to produce a waste plastic pyrolysis oil feedstock. 
     
     
         12 . The method of  claim 11 , wherein the pyrolysis reactor in step (S0) comprises a rotary kiln reactor. 
     
     
         13 . The method of  claim 1 , wherein the refined oil recovered in step (S4) has a content of chlorine reduced by 50% or more compared to a content of chlorine in the waste plastic pyrolysis oil feedstock in step (S1). 
     
     
         14 . The method of  claim 1 , wherein the refined oil recovered in step (S4) has a content of each of nitrogen, sulfur, and/or oxygen reduced by 20% or more compared to a content of each of nitrogen, sulfur, and/or oxygen of the waste plastic pyrolysis oil feedstock in step (S1). 
     
     
         15 . The method of  claim 1 , wherein a weight ratio of the refined oil recovered in step (S4) to light oil in the waste plastic pyrolysis oil feedstock in step (S1) is 1.3 or more. 
     
     
         16 . A device for refining waste plastic pyrolysis oil, the device comprising:
 a rotary kiln reactor into which a waste plastic pyrolysis oil feedstock is introduced;   a gas separator into which a gas component is introduced from the rotary kiln reactor;   a condenser into which a light gas component is introduced from the gas separator; and   a re-supply line in which a high boiling point wax component is separated in the gas separator and the separated high boiling point wax component is re-supplied to the rotary kiln reactor.   
     
     
         17 . The device of  claim 16 , wherein the rotary kiln reactor sequentially comprises a first zone, a second zone, and a third zone in a direction from a feedstock inlet to an outlet. 
     
     
         18 . The device of  claim 16 , wherein the rotary kiln reactor comprises a batch reactor.