Removal of silicon from depolymerized oil

Abstract

The present disclosure relates to an improved method of removing silicon from depolymerized oil, more specifically to a method of producing a pyrolysis oil, the method including adding alumina in the form of granules to organic silicon-containing waste plastic to form a mixture, feeding the mixture to a pyrolysis reactor, pyrolysing the mixture in the reactor, recovering at least a pyrolysis gas and a solid residue from the reactor, and condensing the pyrolysis gas to provide an oil product, wherein the solid residue includes the alumina reacted with silicon.

1 - 15 . (canceled) 
     
     
         16 . A method of producing a pyrolysis oil, the method comprising:
 adding alumina formed as granules to organic silicon-containing waste plastic to form a mixture;   feeding said mixture to a pyrolysis reactor;   pyrolysing said mixture in said pyrolysis reactor;   recovering at least a pyrolysis gas and a solid residue from said pyrolysis reactor; and   condensing the pyrolysis gas to provide an oil product;   wherein the solid residue includes the alumina reacted with silicon.   
     
     
         17 . The method according to  claim 16 , comprising:
 adding the alumina in an amount of 0.2 to 40.0 wt.-%, and/or 0.5 to 35.0 wt.-%, 1.0 to 30.0 wt.-%, 1.5 to 25.0 wt.-%, 2.0 to 20.0 wt.-%, 2.5 to 15.0 wt.-%, 3.0 to 13.0 wt.-%, 4.0 to 12.0 wt.-%, 5.0 to 11.0 wt.-%, 5.5 to 10.0 wt.-%, and/or 6.0 to 9.0 wt.-%.   
     
     
         18 . The method according to  claim 16 , comprising:
 carrying out said adding alumina to form a mixture out at a temperature in a range of from 50° C. to 280° C., and/or in a range of from 60° C. to 270° C., 80° C. to 260° C., 100° C. to 250° C., 110° C. to 250° C., 120° C. to 250° C., 130° C. to 240° C., 140° C. to 230° C., and/or 150° C. to 220° C.   
     
     
         19 . The method according to  claim 16 , wherein said adding alumina to form a mixture comprises:
 melting the waste plastic.   
     
     
         20 . The method according to  claim 16 , comprising:
 carrying out said adding alumina to form a mixture in an extruder, and/or in a melt extruder.   
     
     
         21 . The method according to  claim 16 , wherein the alumina has an open pore structure. 
     
     
         22 . The method according to  claim 16 , wherein the alumina has a BET specific surface area in a range of from 50 m 2 /g to 500 m 2 /g, and/or above 50 m 2 /g, above 100 m 2 /g, or 150 m 2 /g or more, and/or in a range of from 100 to 300 m 2 /g, and/or in a range of from 150 to 300 m 2 /g. 
     
     
         23 . The method according to  claim 16 , comprising:
 carrying out the pyrolysis out in two or more steps.   
     
     
         24 . The method according to  claim 16 , comprising:
 carried out a first pyrolysis step in an absence of a pyrolysis catalyst, and at least one subsequent pyrolysis step(s) in a presence of a pyrolysis catalyst.   
     
     
         25 . The method according to  claim 16 , comprising:
 adding a Group II metal oxide or Group II metal hydroxide (Group II metal oxide/hydroxide) with the adding of alumina to form a mixture and/or directly to the pyrolysis reactor, wherein the Group II metal is magnesium or calcium.   
     
     
         26 . The method according to  claim 25 , wherein the Group II metal oxide/hydroxide is at least one selected from the group consisting of:
 calcium oxide and calcium hydroxide.   
     
     
         27 . The method according to  claim 25 , comprising:
 adding the Group II metal oxide/hydroxide in an amount in a range of 0.2 to 40.0 wt.-%, and/or in an amount in a range of 0.5 to 35.0 wt.-%, 1.0 to 30.0 wt.-%, 1.5 to 25.0 wt.-%, 2.0 to 20.0 wt.-%, 2.5 to 15.0 wt.-%, 3.0 to 13.0 wt.-%, 4.0 to 12.0 wt.-%, 5.0 to 11.0 wt.-%, 5.0 to 10.0 wt.-%, and/or 5.5 to 9.0 wt.-%.   
     
     
         28 . The method according to  claim 16 , comprising:
 heating the organic silicon-containing waste plastic and/or the mixture to an elevated temperature; and   devolatilising, at least part of organic silicon compound(s) contained therein, wherein the heating is conducted at a temperature in a range of 175° C. to 280° C., and/or as 180° C. to 270° C., 185° C. to 265° C., 190° C. to 260° C., 200° C. to 255° C., and/or 210° C. to 250° C., prior to feeding said mixture into the pyrolysis reactor.   
     
     
         29 . The method according to  claim 16 , wherein the alumina is acidic alumina, and/or activated acidic alumina. 
     
     
         30 . A method comprising:
 providing alumina formed as alumina granules; and   adding the alumina granules to an in-situ reduction of an amount of organic silicon in a waste plastic pyrolysis process.