Hydroconversion in an ebullated or hybrid ebullated/entrained bed of a feedstock comprising a plastic fraction

Abstract

The present invention relates to a process for the hydroconversion of a feedstock including a plastic fraction (102), notably derived from plastic waste, and a heavy hydrocarbon fraction (101), notably a heavy hydrocarbon fraction containing a portion of at least 50% by weight, preferably at least 80% by weight, having a boiling temperature of at least 300° C. Hydroconversion involves one or more ebullated bed or hybrid ebullated-entrained bed reactors (20), and preferably two successive hydroconversion steps, in order to produce higher-quality, lower-boiling materials, for example for fuel production purposes, while at the same time allowing waste plastics to be upgraded.

1 . A process for the hydroconversion of a feedstock, comprising:
 (a) conditioning and introducing said feedstock into a first hydroconversion section ( 20 ) including at least a first ebullated-bed or hybrid ebullated-entrained hydroconversion reactor comprising a first porous supported hydroconversion catalyst, said feedstock including between 1% and 50% by weight of a plastic fraction and 50% and 99% by weight of a heavy hydrocarbon fraction containing a portion of at least 50% by weight having a boiling point of at least 300° C., and containing sulfur, and nitrogen;   (b) hydroconverting said feedstock in the presence of hydrogen in said first hydroconversion section ( 20 ) to obtain a first hydroconverted effluent ( 105 );   (c) optionally, separating part or all of said first effluent resulting from (b), to form at least one heavy cut boiling predominantly at a temperature greater than or equal to 350° C.;   (d) optionally, hydroconverting in a second hydroconversion section including at least a second ebullated bed or hybrid ebullated-entrained bed hydroconversion reactor of part or all of said first effluent resulting from (b) or optionally of said heavy cut resulting from (c), said second hydroconversion reactor comprising a second porous supported catalyst and operating in the presence of hydrogen, to produce a second hydroconverted effluent;   wherein (b) and optionally (d) are performed at an absolute pressure of between 2 MPa and 38 MPa, at a temperature of between 300° C. and 550° C., at an hourly space velocity relative to the volume of each hydroconversion reactor of between 0.05 h-1 and 10 h-1, and with an amount of hydrogen of between 50 Nm3/m3 and 5000 Nm3/m3, and   (e) fractionating all or some of said first hydroconverted effluent from (b) or said second hydroconverted effluent from (d), in a fractionation section ( 30 ), to produce at least one heavy liquid product ( 106   b ) boiling predominantly at a temperature greater than or equal to 350° C., said heavy liquid product containing a residual fraction boiling at a temperature greater than or equal to 540° C.   
     
     
         2 . The process as claimed in  claim 1 , in which, in (a), the plastic fraction and the heavy hydrocarbon fraction of the feedstock ( 114 ,  117 ,  120 ,  122 ,  125 ) are introduced mixed into said at least one first hydroconversion reactor of the first hydroconversion section ( 20 ). 
     
     
         3 . The process as claimed in  claim 2 , in which, in (a), the plastic fraction in the form of solid particles ( 102 ) is mixed with the heavy hydrocarbon fraction ( 101 ) in such a way as to form a suspension ( 113 ), said suspension ( 113 ) being heated to a temperature above the melting point of said plastic fraction to form the feedstock ( 114 ) introduced into the first hydroconversion reactor. 
     
     
         4 . The process as claimed in  claim 2 , in which, in (a), the plastic fraction in the form of solid particles ( 102 ) is premixed with a plastic diluent ( 107 ) to form a first suspension ( 115 ), and said first suspension ( 115 ) is then mixed with the heavy hydrocarbon fraction ( 101 ) to form a second suspension ( 116 ), said second suspension ( 116 ) being heated to a temperature above the melting temperature of said plastic fraction to form the feedstock ( 117 ) introduced into the first hydroconversion reactor. 
     
     
         5 . The process as claimed in  claim 2 , in which, in (a), the plastic fraction in the form of solid particles ( 102 ) is heated to a temperature above the melting point of said plastic fraction to form a molten plastic fraction ( 118 ,  121 ), and said molten plastic fraction ( 118 ,  121 ) is then mixed with the heavy hydrocarbon fraction ( 101 ) in such a manner as to form the feedstock ( 119 ,  122 ) introduced into the first hydroconversion reactor. 
     
     
         6 . The process as claimed in  claim 2 , in which, in (a), the plastic fraction in the form of solid particles ( 102 ) is heated to a temperature above the melting point of said plastic fraction to form a molten plastic fraction ( 123 ), and said molten plastic fraction ( 123 ) is then mixed with a plastic diluent ( 107 ) to form a dilute molten plastic fraction ( 124 ) mixed with the heavy hydrocarbon fraction ( 101 ) to form the feedstock ( 125 ) introduced into the first hydroconversion reactor. 
     
     
         7 . The process as claimed in  claim 1 , in which, in (a), the plastic fraction ( 103 ,  109 ,  110 ,  112 ) and the heavy hydrocarbon fraction ( 101 ) of the feedstock are introduced separately into said at least one first hydroconversion reactor of the first hydroconversion section ( 20 ). 
     
     
         8 . The process as claimed in  claim 7 , in which, in (a), the plastic feedstock in the form of solid particles ( 102 ) is sent into an extruder ( 10 ) in which it is gradually heated to a temperature greater than the melting point of said plastic fraction, and placed at the pressure of the first hydroconversion reactor, during a conveying, and said extruded plastic fraction ( 103 ) is introduced into the first hydroconversion reactor. 
     
     
         9 . The process as claimed in  claim 7 , in which, in (a), the plastic fraction in the form of solid particles is mixed with a plastic diluent ( 107 ) in a mixing section ( 11 ) and heated in a heating section ( 12 ) to a temperature greater than the melting point of said plastic fraction before its introduction into the first hydroconversion reactor, it being possible for the heating to be performed before or after the mixing with the plastic diluent. 
     
     
         10 . The process as claimed in  claim 7 , in which, in (a), the plastic fraction in the form of solid particles is previously sent to a mixer ( 13 ) to be mixed with a plastic diluent ( 107 ) and form a suspension ( 110 ) and said plastic fraction in the form of a suspension ( 110 ) is introduced into the first hydroconversion reactor. 
     
     
         11 . The process as claimed in  claim 7 , in which, in (a), the plastic fraction in the form of solid particles is premixed with a plastic diluent ( 107 ) and with the first porous supported hydroconversion catalyst in a distribution and mixing box ( 14 ) to form a suspension ( 112 ), and said suspension ( 112 ) is then introduced into the first hydroconversion reactor via the means for injecting the catalyst into said first hydroconversion reactor. 
     
     
         12 . The process as claimed in  claim 1 , in which the feedstock includes between 5% and 30% by weight of said plastic fraction, and between 70% and 95% by weight of said heavy hydrocarbon fraction. 
     
     
         13 . The process as claimed in  claim 1 , including the separation (c) of separating part, or all, of the first hydroconverted effluent ( 105 ) from (b) to produce at least the heavy cut boiling predominantly at a temperature greater than or equal to 350° C., and including (d) the hydroconverting of said heavy cut. 
     
     
         14 . The process as claimed in  claim 1 , in which the hydroconversion reactor(s) of the first hydroconversion section ( 20 ) in (b), and optionally in hydroconversion (d), are hybrid ebullated-entrained bed reactors, said process also including introducing a catalyst precursor ( 104 ), preferably molybdenum 2-ethylhexanoate, prior to injection of said feedstock into said at least one first ebullated-entrained hybrid bed reactor of the first hydroconversion section ( 20 ), in such a way that a colloidal or molecular catalyst, preferably including molybdenum disulfide, is formed when said feedstock reacts with sulfur. 
     
     
         15 . The process as claimed in  claim 1 , in which the first hydroconversion catalyst, and optionally the second hydroconversion catalyst, contains at least one non-noble Group VIII metal chosen from nickel and cobalt, preferably nickel, and at least one Group VIB metal chosen from molybdenum and tungsten, preferably molybdenum, and including an amorphous support, preferably alumina. 
     
     
         16 . The process as claimed in  claim 2 , in which, in (a), the plastic fraction in the form of solid particles ( 102 ), premixed with a plastic diluent ( 107 ) to form a suspension ( 120 ), is heated to a temperature above the melting point of said plastic fraction to form a molten plastic fraction ( 118 ,  121 ), and said molten plastic fraction ( 118 ,  121 ) is then mixed with the heavy hydrocarbon fraction ( 101 ) in such a manner as to form the feedstock ( 119 ,  122 ) introduced into the first hydroconversion reactor. 
     
     
         17 . The process as claimed in  claim 7 , in which, in (a), the plastic feedstock in the form of solid particles ( 102 ) is sent into an extruder ( 10 ), with a plastic diluent ( 107 ), in which it is gradually heated to a temperature greater than the melting point of said plastic fraction, and placed at the pressure of the first hydroconversion reactor, during a conveying for a period of time of less than 15 minutes, and said extruded plastic fraction ( 103 ) is introduced into the first hydroconversion reactor. 
     
     
         18 . The process as claimed in  claim 7 , in which, in (a), the plastic fraction in the form of solid particles is mixed with a plastic diluent ( 107 ) in a mixing section ( 11 ) and heated in a heating section ( 12 ) to a temperature of between 60° C. and 295° C., before its introduction into the first hydroconversion reactor, it being possible for the heating to be performed before or after the mixing with the plastic diluent and after the mixing with the plastic diluent. 
     
     
         19 . The process as claimed in  claim 7 , in which, in (a), the plastic fraction in the form of solid particles is previously sent to a mixer ( 13 ) to be mixed with a plastic diluent ( 107 ) and form a suspension ( 110 ), at a temperature greater than or equal to room temperature and less than the melting temperature of said plastic fraction, and said plastic fraction in the form of a suspension ( 110 ) is introduced into the first hydroconversion reactor. 
     
     
         20 . The process as claimed in  claim 1 , in which the feedstock includes between 5% and 20% by weight of said plastic fraction, and between 80% and 95% by weight of said heavy hydrocarbon fraction.