Methods for treatment of mixed plastic waste pyrolysis oil

Abstract

Systems and methods for pretreating a raw mixed plastic waste pyrolysis oil using a solid adsorbent, a solid acid, a solid base and/or an ion exchange resin and then processing the pretreated mixed plastic waste pyrolysis oil by hydrotreating processes.

What is claimed is: 
     
         1 . A method of pretreating a raw mixed plastic waste pyrolysis oil, the method comprising:
 supplying a raw mixed plastic pyrolysis oil containing at least one contaminant to a reaction vessel, the contaminant being one or more of diolefin compounds, oxygen compounds, nitrogen compounds, or chloride compounds;   contacting the raw mixed plastic waste pyrolysis oil with at least one of a solid acid or a solid alkali in the reaction vessel;   causing deposition of a portion of the at least one contaminant from the raw mixed plastic waste pyrolysis oil onto the at least one of the solid acid or the solid alkali; and   separating the at least one of the solid acid or the solid alkali containing deposition of the portion of the at least one contaminant from the raw mixed plastic waste pyrolysis oil to produce a pre-treated mixed plastic waste pyrolysis oil.   
     
     
         2 . The method of  claim 1 , wherein separating the at least one of the solid acid or the solid alkali containing deposition of the portion of the at least one contaminant from the raw mixed plastic waste pyrolysis oil occurs by one or more of filtration, centrifugation, settling, or hydrocyclonization. 
     
     
         3 . The method of  claim 1 , wherein the solid acid, the solid alkali, or both are present in the form of pellets. 
     
     
         4 . The method of  claim 1 , wherein the solid acid, the solid alkali, or both include an anionic or cationic ion exchange resin. 
     
     
         5 . The method of  claim 4 , further comprising:
 regenerating the anionic or cationic ion exchange resin.   
     
     
         6 . The method of  claim 1 , further comprising:
 supplying the at least one of the solid acid or the solid alkali with the at least one contaminant to a regeneration unit;   calcining the at least one of the solid acid or the solid alkali with the at least one contaminant in the regeneration unit; and   returning at least one of the calcined solid acid or calcined solid alkali to the reaction vessel.   
     
     
         7 . The method of  claim 1 , wherein the at least one of a solid acid or a solid alkali in the reaction vessel is positioned in a fixed bed arrangement. 
     
     
         8 . The method of  claim 1 , wherein the reaction vessel is a fluidized bed unit. 
     
     
         9 . The method of  claim 8 , wherein the fluidized bed unit is an ebullated bed unit. 
     
     
         10 . A method of processing a raw mixed plastic waste pyrolysis oil, the method comprising:
 supplying a raw mixed plastic pyrolysis oil containing at least one contaminant to a reaction vessel, the contaminant being one or more of diolefin compounds, oxygen compounds, nitrogen compounds, or chloride compounds;   contacting the raw mixed plastic waste pyrolysis oil with at least one of a solid acid or a solid alkali in the reaction vessel;   causing deposition of the at least one contaminant from the raw mixed plastic waste pyrolysis oil onto the at least one of the solid acid or the solid alkali;   separating the at least one of the solid acid or the solid alkali with the at least one contaminant from the raw mixed plastic waste pyrolysis oil to produce a pre-treated mixed plastic waste pyrolysis oil;   introducing the pre-treated mixed plastic waste pyrolysis oil to a hydrotreater;   processing the pre-treated mixed plastic waste pyrolysis oil with a hydrotreating catalyst in the hydrotreater; and   obtaining a hydrotreated mixed plastic waste pyrolysis oil from the hydrotreater.   
     
     
         11 . The method of  claim 10 , wherein processing the pre-treated mixed plastic waste pyrolysis oil with the hydrotreating catalyst in the hydrotreater includes converting:
 at least some of the diolefin compounds in the pre-treated mixed plastic waste pyrolysis oil into one or more saturated hydrocarbon compounds,   at least some of the nitrogen compounds in the pre-treated mixed plastic waste pyrolysis oil into one or more ammonia-containing compounds, and   at least some of the oxygen compounds into water, carbon monoxide, or carbon dioxide.   
     
     
         12 . A method of removing contaminants from raw mixed plastic waste pyrolysis oil, the method comprising:
 obtaining a raw mixed plastic pyrolysis oil containing one or more of diolefin compounds, oxygen compounds, nitrogen compounds, and chloride compounds;   contacting the raw mixed plastic pyrolysis oil with a solid adsorbent, the solid adsorbent being one or more of activated carbon, aluminosilicate, and silica;   causing adsorption of a portion of the one or more diolefin compounds, oxygen compounds, nitrogen compounds, and chloride compounds from the raw mixed plastic pyrolysis oil on a plurality of pores in the solid adsorbent, thereby producing a pre-treated mixed plastic waste pyrolysis oil, the pre-treated mixed plastic waste pyrolysis oil containing reduced amounts of the one or more of diolefin compounds, oxygen compounds, nitrogen compounds, and chloride compounds as compared to the raw mixed plastic pyrolysis oil;   separating the pre-treated mixed plastic waste pyrolysis oil from the solid adsorbent;   introducing the pre-treated mixed plastic waste pyrolysis oil to a hydrotreater;   processing the pre-treated mixed plastic waste pyrolysis oil with a hydrotreating catalyst in the hydrotreater; and   obtaining a hydrotreated mixed plastic waste pyrolysis oil from the hydrotreater, the hydrotreated mixed plastic waste pyrolysis oil containing reduced amounts of the one or more of diolefin compounds, oxygen compounds, nitrogen compounds, and chloride compounds as compared to the pre-treated mixed plastic waste pyrolysis oil.   
     
     
         13 . The method of  claim 12 , wherein separating the pre-treated mixed plastic waste pyrolysis oil from the solid adsorbent is conducted through centrifugation, filtration, settling, or hydrocyclonization. 
     
     
         14 . The method of  claim 12 , wherein the raw mixed plastic pyrolysis oil is in contact with the solid adsorbent inside a fixed bed unit. 
     
     
         15 . The method of  claim 12 , wherein the raw mixed plastic pyrolysis oil is in contact with the solid adsorbent inside a fluidized bed unit. 
     
     
         16 . The method of  claim 15 , wherein the fluidized bed unit is an ebullated bed unit. 
     
     
         17 . The method of  claim 16 , wherein the solid adsorbent is present in a ratio of solid to liquid components from about 20 to about 30 volume percent. 
     
     
         18 . The method of  claim 12 , wherein the solid adsorbent is activated carbon. 
     
     
         19 . The method of  claim 18 , wherein an amount of nitrogen compounds in the pre-treated mixed plastic waste pyrolysis oil is reduced by at least about 40 percent as compared to amount of nitrogen compounds in the raw mixed plastic pyrolysis oil. 
     
     
         20 . The method of  claim 18 , wherein an amount of oxygen compounds in the pre-treated mixed plastic waste pyrolysis oil is reduced by at least about 40 percent as compared to amount of oxygen compounds in the raw mixed plastic pyrolysis oil.