Method of producing a fuel oil including pyrolysis products generated from mixed waste plastics

Abstract

Method of producing a fuel oil comprising pyrolysis products from waste plastics includes conducting pyrolysis of a plastic feedstock to produce plastic pyrolysis oil; feeding the plastic pyrolysis oil to a first fractionator to separate the plastic pyrolysis oil into a distillate fraction and a topped pyrolysis product fraction split at a boiling point in the range of 80° C. to 250° C.; and feeding the topped pyrolysis product fraction along with other hydrocarbon streams to a fuel oil blending unit to generate a fuel oil product stream. An associated system for preparing a fuel oil comprising pyrolysis products from waste plastics is also provided.

What is claimed is: 
     
         1 . A method of producing a fuel oil comprising pyrolysis products from waste plastics, the method comprising:
 (a) conducting pyrolysis of a plastic feedstock to produce a stream of plastic pyrolysis oil, the plastic feedstock consisting of plastics which comprise mixed waste plastics, the mixed waste plastics comprising one or more of polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate, and polyacrylonitrile;   (b) feeding the plastic pyrolysis oil to a first fractionator to separate the plastic pyrolysis oil at a first cut temperature, where the first cut temperature is in the range of 80° C. to 250° C. such that the plastic pyrolysis oil is split into a distillate fraction comprising hydrocarbons boiling in the range of 36° C. to the first cut temperature and a topped pyrolysis product fraction comprising hydrocarbons boiling above the first cut temperature; and   (c) feeding the topped pyrolysis product fraction along with one or more streams selected from the group consisting of a kerosene stream, a light gas oil stream, a vacuum residue stream, a FCC clarified oil stream, and an aromatic bottoms stream to a fuel oil blending unit to generate a fuel oil product stream,   wherein the kerosene stream comprises hydrocarbons boiling in the range of 150 to 240° C. the light gas oil comprises hydrocarbons boiling in the range of 240 to 320° C. the vacuum residue comprises hydrocarbons boiling above 480° C., the FCC clarified oil stream comprises hydrocarbons from a fluid catalytic cracking unit boiling above 480° C., and the aromatic bottoms stream comprises aromatics with carbon number of 9 and greater.   
     
     
         2 . The method of  claim 1 , where the plastic pyrolysis oil up to 90 weight percent of paraffins, up to 90 weight percent olefins, up to 45 weight percent naphtenes, and up to 10 weight percent aromatics 
     
     
         3 . The method of  claim 1 , where the fuel oil product stream comprises a specific gravity (15/15° C.) of 1.010 or less, a sulfur content of 3.7 weight percent or less, a kinematic viscosity (at 50° C.) of 700 cSt or less, a flash point of 60.0° C. or greater, and a carbon residue of 20.0 weight percent or less. 
     
     
         4 . The method of  claim 1 , where the plastic feedstock comprises mixed plastics of differing compositions. 
     
     
         5 . The method of  claim 1 , where the pyrolysis of the plastic feedstock is performed in the presence of a catalyst at a temperature of 300° C. to 1000° C. 
     
     
         6 . The method of  claim 1 , where the first cut temperature is 80° C. such that the distillate fraction comprises hydrocarbons boiling in the range of 36 to 80° C. and the topped pyrolysis product fraction comprises hydrocarbons boiling above 80° C. 
     
     
         7 . The method of  claim 1 , where the first cut temperature is 160° C. such that the distillate fraction comprises hydrocarbons boiling in the range of 36 to 160° C. and the topped pyrolysis product fraction comprises hydrocarbons boiling above 160° C. 
     
     
         8 . The method of  claim 1 , where the first cut temperature is 180° C. such that the distillate fraction comprises hydrocarbons boiling in the range of 36 to 180° C. and the topped pyrolysis product fraction comprises hydrocarbons boiling above 180° C. 
     
     
         9 . The method of  claim 1 , where the first cut temperature is 240° C. such that the distillate fraction comprises hydrocarbons boiling in the range of 36 to 240° C. and the topped pyrolysis product fraction comprises hydrocarbons boiling above 240° C. 
     
     
         10 . The method of  claim 1 , where the fuel oil product stream comprises 0.5 to 20 volume percent of the topped pyrolysis product fraction. 
     
     
         11 . The method of  claim 1 , where the plastic pyrolysis oil comprises less than 10,000 ppm by weight sulfur. 
     
     
         12 . The method of  claim 1 , where the kerosene stream, the light gas oil stream, the vacuum residue stream, the FCC clarified oil stream, and the aromatic bottoms stream, as present, are provided as separate streams to the fuel oil blending unit with each of the kerosene stream, the light gas oil stream, the vacuum residue stream, the FCC clarified oil stream, and the aromatic bottoms stream individually flow controlled. 
     
     
         13 . The method of  claim 1 , where the kerosene stream, the light gas oil stream, the vacuum residue stream, the FCC clarified oil stream, and the aromatic bottoms stream, as present, are provided as a single bulk fuel oil stream to the fuel oil blending unit,
 wherein each of the kerosene stream, the light gas oil stream, the vacuum residue stream, the FCC clarified oil stream, and the aromatic bottoms stream individually flow controlled to form the bulk fuel oil stream.   
     
     
         14 . A system for preparing a fuel oil comprising pyrolysis products from waste plastics, the system comprising:
 an inlet stream consisting of plastics which comprise mixed plastics, the mixed plastics comprising one or more of polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate and polyacrylonitrile;   a plastic pyrolysis unit, the plastic pyrolysis unit in fluid communication with the inlet stream, and operable to generate a stream of plastic pyrolysis oil from the inlet stream;   a first fractionator, the first fractionator in fluid communication with the plastic pyrolysis unit and operable to separate the stream of plastic pyrolysis oil at a first cut temperature, where the first cut temperature is in the range of 80° C. to 250° C. such that the plastic pyrolysis oil is split into a distillate fraction comprising hydrocarbons boiling in the range of 36° C. to the first cut temperature and a topped pyrolysis product fraction comprising hydrocarbons boiling above the first cut temperature; and   a fuel oil blending unit, the fuel oil blending unit in fluid communication with the first fractionator to blend the topped pyrolysis product fraction with one or more streams selected from the group consisting of a kerosene stream, a light gas oil stream, a vacuum residue stream, a FCC clarified oil stream, and an aromatic bottoms stream to generate a fuel oil product stream,   wherein the kerosene stream comprises hydrocarbons boiling in the range of 150 to 240° C., the light gas oil comprises hydrocarbons boiling in the range of 240 to 320° C., the vacuum residue comprises hydrocarbons boiling above 480° C., the FCC clarified oil stream comprises hydrocarbons from a fluid catalytic cracking unit boiling above 480° C., and the aromatic bottoms stream comprises aromatics with carbon number of 9 and greater.   
     
     
         15 . The system of  claim 14 , where the kerosene stream, the light gas oil stream, the vacuum residue stream, the FCC clarified oil stream, and the aromatic bottoms stream, as present, are provided as separate streams to the fuel oil blending unit with each of the kerosene stream, the light gas oil stream, the vacuum residue stream, the FCC clarified oil stream, and the aromatic bottoms stream individually flow controlled. 
     
     
         16 . The system of  claim 14 , where the kerosene stream, the light gas oil stream, the vacuum residue stream, the FCC clarified oil stream, and the aromatic bottoms stream, as present, are provided as a single bulk fuel oil stream to the fuel oil blending unit,
 wherein each of the kerosene stream, the light gas oil stream, the vacuum residue stream, the FCC clarified oil stream, and the aromatic bottoms stream individually flow controlled to form the bulk fuel oil stream.   
     
     
         17 . The system of  claim 14 , where the plastic pyrolysis oil comprises up to 90 weight percent of paraffins, up to 90 weight percent olefins, up to 45 weight percent naphtenes, and up to 10 weight percent aromatics. 
     
     
         18 . The system of  claim 14 , where the first cut temperature is 80° C. such that the distillate fraction comprises hydrocarbons boiling in the range of 36 to 80° C. and the topped pyrolysis product fraction comprises hydrocarbons boiling above 80° C. 
     
     
         19 . The system of  claim 14 , where the first cut temperature is 180° C. such that the distillate fraction comprises hydrocarbons boiling in the range of 36 to 180° C. and the topped pyrolysis product fraction comprises hydrocarbons boiling above 180° C. 
     
     
         20 . The system of  claim 14 , where the fuel oil product stream comprises 0.5 to 20 volume percent of the topped pyrolysis product fraction.