Methods and systems for decontamination of pyrolysis oil using modular units

Abstract

Modular systems and methods for removal of contaminants from a mixed plastic waste pyrolysis oil and optionally processing it in a hydrogenation unit to produce a decontaminated hydrogenated pyrolysis oil. These contaminants include metal compounds and non-metal compounds, such as silica compounds, halogenated compounds, phosphorous compounds, oxygenates, and nitrogenates.

What is claimed is: 
     
         1 . A method of removing metal compounds and non-metal compounds from a mixed plastic waste pyrolysis oil, the method comprising:
 obtaining a mixed plastic waste pyrolysis oil containing metal compounds and non-metal compounds, the non-metal compounds being two or more of silica compounds, halogenated compounds, phosphorous compounds, oxygenates, and nitrogenates;   passing the mixed plastic waste pyrolysis oil through a first adsorption bed with a first porous bed material to adsorb a portion of the metal compounds from the mixed plastic waste pyrolysis oil;   passing the mixed plastic waste pyrolysis oil from the first adsorption bed through a second adsorption bed, the second adsorption bed having a second porous bed material to adsorb a portion of the silica compounds from the mixed plastic waste pyrolysis oil, pores of the first porous bed material being greater in size than pores of the second porous bed material;   passing the mixed plastic waste pyrolysis oil from the second adsorption bed through a third adsorption bed, the third adsorption bed having a third porous bed material to adsorb a portion of the halogenated compounds from the mixed plastic waste pyrolysis oil, the pores of the second porous bed material being greater in size than pores of the third porous bed material;   introducing the mixed plastic waste pyrolysis oil from the third adsorption bed into a vessel containing a plurality of molecular sieves, the plurality of molecular sieves to adsorb a portion of oxygenates, phosphorous compounds and nitrogenates from the mixed plastic waste pyrolysis oil and produce a partially decontaminated pyrolysis oil;   supplying the partially decontaminated pyrolysis oil from the vessel to a hydrogenation unit; and   processing the partially decontaminated pyrolysis oil in presence of a hydrogenation catalyst in the hydrogenation unit to convert a portion of the olefin compounds in the partially decontaminated pyrolysis oil into saturated hydrocarbon compounds to produce a decontaminated hydrogenated pyrolysis oil with a reduced amount of the metal compounds and the non-metal compounds as compared to the amount of metal compounds and non-metal compounds in the mixed plastic waste pyrolysis oil.   
     
     
         2 . The method of  claim 1 , further comprising:
 prior to passing the mixed plastic waste pyrolysis oil through the first adsorption bed, passing the mixed plastic waste pyrolysis oil through a filter that removes at least a portion of solid particles greater than about 10 microns from the mixed plastic water pyrolysis oil to produce a filtered pyrolysis oil.   
     
     
         3 . The method of  claim 2 , further comprising:
 supplying the filtered pyrolysis oil from the filter to a coalescing unit with a coalescing medium therein to coalesce and separate at least a portion of water from the mixed plastic waste pyrolysis oil.   
     
     
         4 . The method of  claim 3 , further comprising cooling the filtered pyrolysis oil to at least 50° C. before supplying the filtered pyrolysis oil to the coalescing unit. 
     
     
         5 . The method of  claim 3 , wherein the coalescing medium is a pad or a filter cartridge. 
     
     
         6 . The method of  claim 1 , further comprising:
 supplying the partially decontaminated pyrolysis oil to a coalescing unit with a coalescing medium therein to coalesce and separate at least a portion of water from the partially decontaminated pyrolysis oil.   
     
     
         7 . The method of  claim 1 , further comprising:
 prior to passing the mixed plastic waste pyrolysis oil through the first adsorption bed, supplying an acid scavenger to the mixed plastic waste pyrolysis oil.   
     
     
         8 . The method of  claim 1 , further comprising:
 prior to introducing the mixed plastic waste pyrolysis oil into the vessel containing the plurality of molecular sieves, determining if concentrations of the metal compounds or the halogenated compounds in the mixed plastic waste pyrolysis oil are greater than a pre-selected level; and   in response to the concentration of the metal compounds or the halogenated compounds being greater than the pre-selected level, passing the mixed plastic waste pyrolysis oil to a set of absorption beds operating in parallel to the first adsorption bed, the second adsorption bed, and the third adsorption bed.   
     
     
         9 . The method of  claim 1 , further comprising:
 prior to supplying the partially decontaminated pyrolysis oil to the hydrogenation unit, determining if concentrations of oxygenates and nitrogenates in the partially decontaminated pyrolysis oil are greater than a pre-selected level; and   in response to the concentration of the oxygenates and nitrogenates in the partially decontaminated pyrolysis oil being greater than the pre-selected level, introducing the partially decontaminated pyrolysis oil from the third adsorption bed into a second vessel containing a second plurality of molecular sieves.   
     
     
         10 . The method of  claim 1 , further comprising:
 adding an oxidation stabilizer to the decontaminated hydrogenated pyrolysis oil.   
     
     
         11 . The method of  claim 1 , further comprising:
 adding a nitrogen blanket to the decontaminated hydrogenated pyrolysis oil.   
     
     
         12 . The method of  claim 1 , further comprising:
 prior to passing the mixed plastic waste pyrolysis oil through the first adsorption bed, cooling the mixed plastic pyrolysis oil to a pre-selected temperature.   
     
     
         13 . The method of  claim 1 , further comprising:
 operating the hydrogenation unit at a temperature between about 80° C. and about 120° C.   
     
     
         14 . The method of  claim 1 , wherein the first porous bed material contains one or more of alumina, ligand-modified alumina, magnesium metal alloys, calcium oxide, clay, calcium carbonate, acid-modified carbon, and activated charcoal. 
     
     
         15 . The method of  claim 1 , wherein the second porous bed material contains one or more of nickel-impregnated silicates, nickel-impregnated hydrotalcites, magnesium-impregnated silicates, magnesium-impregnated hydrotalcites, nickel-modified zeolites, magnesium-modified zeolites, sulfonated silica, polyacrylamide, a copolymer of tetrafluoroethylene and perfluoro-3,6-dioxa-4-methyl-7-octene-sulfonic acid, polyvinyl alcohol, ion exchange resins, and a modified-polydivinylbenzene. 
     
     
         16 . The method of  claim 1 , wherein the third bed material contains one or more of modified alumina, modified zeolites, modified silicates, modified phosphates, red mud, calcium hydroxide, aluminum-zinc carbon composites, calcium carbonate, and aluminum-magnesium composite oxides. 
     
     
         17 . A method of removing metal compounds and non-metal compounds from a mixed plastic waste pyrolysis oil, the method comprising:
 obtaining a mixed plastic waste pyrolysis oil containing metal compounds and non-metal compounds, the non-metal compounds being two or more of silica compounds, halogenated compounds, phosphorous compounds, oxygenates, and nitrogenates;   passing the mixed plastic waste pyrolysis oil through a filter medium to remove a portion of solid particles greater than about 10 microns from the mixed plastic water pyrolysis oil to produce a filtered mixed plastic waste pyrolysis oil;   cooling the filtered mixed plastic waste pyrolysis oil to a temperature at least below 50° C.;   introducing the filtered mixed plastic waste pyrolysis oil into a coalescing unit having a coalescing medium to separate at least a portion of water from the filtered mixed plastic waste pyrolysis oil;   passing the filtered mixed plastic waste pyrolysis oil through a first medium in a first trap to remove a portion of the metal compounds from the filtered mixed plastic waste pyrolysis oil;   passing the filtered mixed plastic waste pyrolysis oil from the first trap through a second medium in a second trap to remove a portion of the silica compounds from the filtered mixed plastic waste pyrolysis oil;   passing the filtered mixed plastic waste pyrolysis oil from the second trap through a third medium in a third trap to remove a portion of the halogenated compounds from the filtered mixed plastic waste pyrolysis oil;   conveying the filtered mixed plastic waste pyrolysis oil from the third trap to a molecular sieve unit with a plurality of molecular sieves, each of the plurality of molecular sieves containing pores therein that adsorb at least a portion of the oxygenates or nitrogenates or phosphorous compounds from the filtered mixed plastic waste pyrolysis oil to produce a partially decontaminated pyrolysis oil;   supplying the partially decontaminated pyrolysis oil to a hydrogenation unit; and   processing the partially decontaminated pyrolysis oil in presence of a hydrogenation catalyst in the hydrogenation unit to convert at least a portion of the olefin compounds in the partially decontaminated pyrolysis oil into one or more saturated hydrocarbon compounds and to produce a decontaminated hydrogenated pyrolysis oil with a reduced amount of the metal compounds and the non-metal compounds as compared to the amount of the metal compounds and the non-metal compounds in the mixed plastic waste pyrolysis oil.   
     
     
         18 . The method of  claim 17 , further comprising operating the hydrogenation unit at a temperature between about 80° C. and about 120° C. 
     
     
         19 . The method of  claim 17 , wherein the first medium contains one or more of alumina, ligand-modified alumina, magnesium metal alloys, calcium oxide, clay, calcium carbonate, acid-modified carbon, and activated charcoal. 
     
     
         20 . The method of  claim 17 , wherein the first medium is a nanofiltration membrane or a polymeric membrane. 
     
     
         21 . The method of  claim 17 , wherein the second medium contains one or more of nickel-impregnated silicates, nickel-impregnated hydrotalcites, magnesium-impregnated silicates, magnesium-impregnated hydrotalcites, nickel-modified zeolites, magnesium-modified zeolites, sulfonated silica, polyacrylamide, a copolymer of tetrafluoroethylene and perfluoro-3,6-dioxa-4-methyl-7-octene-sulfonic acid, polyvinyl alcohol, ion exchange resins, and a modified-polydivinylbenzene. 
     
     
         22 . The method of  claim 17 , wherein the third medium contains one or more of modified alumina, modified zeolites, modified silicates, modified phosphates, red mud, calcium hydroxide, aluminum-zinc carbon composites, calcium carbonate, and aluminum-magnesium composite oxides. 
     
     
         23 . The method of  claim 17 , further comprising:
 adding an acid scavenger to the filtered mixed plastic waste pyrolysis oil prior to passing the mixed plastic waste pyrolysis oil through the first trap.   
     
     
         24 . The method of  claim 17 , further comprising:
 adding an oxidation stabilizer to the decontaminated hydrogenated pyrolysis oil.   
     
     
         25 . A modular system for removing metal compounds and non-metal compounds from a mixed plastic waste pyrolysis oil, the modular system comprising:
 a filter having a first inlet and a first outlet, the first inlet connected to and in fluid communication with a mixed plastic waste pyrolysis oil feed, the filter configured to remove solid particles greater than about 10 microns from the mixed plastic water pyrolysis oil feed to produce a filtered mixed plastic waste pyrolysis oil;   a coalescing unit having a second inlet and a second outlet, the second inlet connected to and in fluid communication with the first outlet, the coalescing unit containing a coalescing medium to separate water from the filtered mixed plastic waste pyrolysis oil;   a metals adsorption bed having a third inlet and a third outlet, the third inlet connected to and in fluid communication with the second outlet, the metals adsorption bed having a first porous bed material to adsorb a portion of metal compounds from the filtered mixed plastic waste pyrolysis oil;   a silica adsorption bed having a fourth inlet and a fourth outlet, the fourth inlet connected to and in fluid communication with the third outlet, the silica adsorption bed having a second porous bed material to adsorb a portion of silica compounds from the filtered mixed plastic waste pyrolysis oil, pores of the second porous bed material being smaller in size than pores of the first porous bed material;   a halogenated compounds adsorption bed having a fifth inlet and a fifth outlet, the fifth inlet connected to and in fluid communication with the fourth outlet, the halogenated compounds adsorption bed having a third porous bed material to adsorb a portion of halogenated compounds from the filtered mixed plastic waste pyrolysis oil, pores of the third porous bed material being smaller in size than the pores of the second porous bed material and the pores of the first porous bed material;   a molecular sieve unit containing a plurality of molecular sieves and having a sixth inlet and a sixth outlet, the sixth inlet connected to and in fluid communication with the fifth outlet, each of the plurality of molecular sieves adsorbing a portion of oxygenates or nitrogenates or phosphorous compounds from the filtered mixed plastic waste pyrolysis oil passing through the molecular sieve unit; and   a hydrogenation unit having a seventh inlet, the seventh inlet connected to and in fluid communication with the sixth outlet of the molecular sieve unit and receiving the filtered mixed plastic waste pyrolysis oil therefrom, the hydrogenation unit having a hydrogenation catalyst therein and being operable to convert at least a portion of olefin compounds in the filtered mixed plastic waste pyrolysis oil into one or more saturated hydrocarbon compounds and produce a decontaminated hydrogenated pyrolysis oil with a reduced amount of plurality of metal compounds and non-metal compounds as compared to the amount of plurality of metal compounds and non-metal compounds in the mixed plastic waste pyrolysis oil.   
     
     
         26 . The system of  claim 25 , further comprising:
 an analyzer positioned to measure a concentration of metal compounds or halogenated compounds in the filtered mixed plastic waste pyrolysis oil before entering the third inlet of the metals adsorption bed.   
     
     
         27 . The system of  claim 25 , further comprising:
 an analyzer positioned to measure a concentration of metal compounds or halogenated compounds in the filtered mixed plastic waste pyrolysis oil downstream of the halogenated compounds adsorption bed.   
     
     
         28 . The system of  claim 25 , further comprising:
 a heat exchanger in thermal communication with the mixed plastic waste pyrolysis oil, the heat exchanger positioned upstream of the metals adsorption bed and configured to maintain temperature of the filtered mixed plastic waste pyrolysis oil within a pre-selected range.   
     
     
         29 . The system of  claim 25 , further comprising:
 a first injector positioned upstream of the metals adsorption bed to supply an acid scavenger into the filtered mixed plastic waste pyrolysis oil; and   a second injector positioned downstream of the hydrogenation unit to supply an oxidation stabilizer into the decontaminated hydrogenated pyrolysis oil.   
     
     
         30 . The system of  claim 25 , wherein the hydrogenation unit has an operating temperature from about 80° C. and about 120° C. 
     
     
         31 . The system of  claim 25 , wherein the first porous bed material contains one or more of alumina, ligand-modified alumina, magnesium metal alloys, calcium oxide, clay, calcium carbonate, acid-modified carbon, and activated charcoal. 
     
     
         32 . The system of  claim 25 , wherein the second porous bed material contains one or more of nickel-impregnated silicates, nickel-impregnated hydrotalcites, magnesium-impregnated silicates, magnesium-impregnated hydrotalcites, nickel-modified zeolites, magnesium-modified zeolites, sulfonated silica, polyacrylamide, a copolymer of tetrafluoroethylene and perfluoro-3,6-dioxa-4-methyl-7-octene-sulfonic acid, polyvinyl alcohol, ion exchange resins, and a modified-polydivinylbenzene. 
     
     
         33 . The system of  claim 25 , wherein the third porous bed material contains one or more of modified alumina, modified zeolites, modified silicates, modified phosphates, red mud, calcium hydroxide, aluminum-zinc carbon composites, calcium carbonate, and aluminum-magnesium composite oxides.