Production of Low Color Middle Distillate Fuels

Abstract

In a process for producing a low color diesel and/or kerosene fuel, a middle distillate feed can be supplied to a reactor having at least one first catalyst bed containing a first desulfurization and/or isomerization catalyst and at least one second catalyst bed containing a decolorization catalyst downstream from the first catalyst bed(s). The feed can be reacted with the hydrogen in the presence of the first catalyst at a temperature from about 290° C. to about 430° C. to produce a first liquid effluent, which can be cooled by about 10° C. to about 40° C. with a quench medium and cascaded to the at least one second catalyst bed. The cooled first liquid effluent can then be reacted with hydrogen in the presence of the decolorization catalyst at a temperature from about 280° C. to about 415° C. to produce a second effluent having an ASTM color less than 2.5.

1 . A process for producing a diesel and/or kerosene fuel of low color, the process comprising:
 (a) supplying a middle distillate feed and hydrogen to a reactor having at least one first catalyst bed containing a first desulfurization and/or isomerization catalyst and at least one second catalyst bed downstream of the first catalyst bed(s) and containing a decolorization catalyst;   (b) reacting the feed with the hydrogen in the presence of the first catalyst in said at least one first catalyst bed at a temperature from about 290° C. to about 430° C. to produce a first liquid effluent;   (c) cooling the first liquid effluent by about 10° C. to about 40° C. with a quench medium;   (d) cascading the entire cooled first liquid effluent to said at least one second catalyst bed; and   (e) contacting the cooled first liquid effluent with hydrogen in the presence of said decolorization catalyst at a temperature of about 280° C. to about 415° C. to produce a second effluent having an ASTM color of less than 2.5.   
     
     
         2 . The process of  claim 1 , wherein said reacting step (b) is conducted at a temperature from about 315° C. to about 400° C. 
     
     
         3 . The process of  claim 1 , wherein the hydrogen partial pressure in the reactor is between about 400 psig (about 2.8 MPag) and about 1500 psig (about 10.3 MPag). 
     
     
         4 . The process of  claim 1 , wherein the first liquid effluent is cooled in step (c) by about 15° C. to about 35° C. 
     
     
         5 . The process of  claim 1 , wherein the quench medium is the second effluent and/or unreacted hydrogen gas from said contacting step (e). 
     
     
         6 . The process of  claim 1 , wherein said contacting step (e) is conducted at a temperature from about 300° C. to about 400° C. 
     
     
         7 . The process of  claim 1 , wherein said second effluent has an ASTM color of less than 2.0. 
     
     
         8 . The process of  claim 1 , wherein said second effluent contains less than 2 vol % of 3+ring aromatic compounds. 
     
     
         9 . A process for producing a low color and low sulfur diesel and/or kerosene fuel, the process comprising:
 (a) supplying a middle distillate feed containing at least 0.03 wt % sulfur and hydrogen to a reactor having at least one first catalyst bed comprising a first desulfurization catalyst and at least one second catalyst bed downstream of the first catalyst bed(s) and comprising a decolorization catalyst;   (b) reacting the feed with hydrogen in the presence of the first catalyst in said at least one first catalyst bed at a temperature from about 315° C. to about 430° C. to produce a first liquid effluent comprising 15 wppm or less sulfur;   (c) cooling the first liquid effluent by about 15° C. to about 35° C. with a quench medium;   (d) cascading the entire cooled first liquid effluent to said at least one second catalyst bed; and   (e) contacting the cooled first liquid effluent with hydrogen in the presence of said decolorization catalyst at a temperature from about 300° C. to about 415° C. to produce a second effluent comprising 15 wppm or less sulfur and having an ASTM color of less than 2.5.   
     
     
         10 . The process of  claim 9 , wherein the desulfurization catalyst comprises nickel and molybdenum. 
     
     
         11 . The process of  claim 9 , wherein the hydrogen partial pressure in the reactor is between about 400 psig (about 2.8 MPag) and about 1500 psig (about 10.3 MPag). 
     
     
         12 . The process of  claim 9 , wherein said reacting step (b) is conducted at an LHSV from about 0.3 hr −1  to about 1.5 hr −1 . 
     
     
         13 . The process of  claim 9 , wherein the quench medium is the second effluent and/or unreacted hydrogen gas from said contacting step (e). 
     
     
         14 . The process of  claim 9 , wherein said contacting step (e) is conducted at an LHSV from about 4 hr −1  to about 10 hr −1 . 
     
     
         15 . The process of  claim 9 , wherein the decolorization catalyst comprises nickel and molybdenum. 
     
     
         16 . The process of  claim 9 , wherein the reactor includes a plurality of first catalyst beds, and wherein at least one of said first catalyst beds comprises an isomerization catalyst. 
     
     
         17 . The process of  claim 16 , wherein the isomerization catalyst is selected from the group consisting of zeolite beta, ZSM-23, ZSM-48, and mixtures thereof 
     
     
         18 . The process of  claim 9 , wherein said second effluent has an ASTM color of less than 2.0. 
     
     
         19 . The process of  claim 9 , wherein said second effluent contains less than 2 vol % of 3+ ring aromatic compounds. 
     
     
         20 . A process for producing a low color diesel and/or kerosene fuel having a low cloud point, the process comprising:
 (a) supplying a middle distillate feed having a first cloud point and hydrogen to a reactor having at least one first catalyst bed comprising a first isomerization catalyst and at least one second catalyst bed downstream of the first catalyst bed(s) and comprising a decolorization catalyst;   (b) reacting the feed with hydrogen in the presence of the first catalyst in said at least one first catalyst bed at a temperature from about 285° C. to about 420° C. to produce a first liquid effluent having a second cloud point that is at least 10° C. less than that of the first cloud point;   (c) cooling the first liquid effluent by about 10° C. to about 20° C. with a quench medium;   (d) cascading the entire cooled first liquid effluent to said at least one second catalyst bed; and   (e) contacting the cooled first liquid effluent with hydrogen in the presence of said decolorization catalyst at a temperature from about 275° C. to about 400° C. to produce a second effluent having a third cloud point that is at least 10° C. less than that of the first cloud point and having an ASTM color of less than 2.5.   
     
     
         21 . The process of  claim 20 , wherein the isomerization catalyst is selected from the group consisting of zeolite beta, ZSM-23, ZSM-48, and mixtures thereof. 
     
     
         22 . The process of  claim 20 , wherein the hydrogen partial pressure in the reactor is between about 500 psig (about 3.4 MPag) and about 1300 psig (about 9.0 MPag). 
     
     
         23 . The process of  claim 20 , wherein said reacting step (b) is conducted at an LHSV from about 1 hr −1  to about 4 hr −1 . 
     
     
         24 . The process of  claim 20 , wherein the quench medium is the second effluent and/or unreacted hydrogen gas from said contacting step (e). 
     
     
         25 . The process of  claim 20 , wherein said contacting step (e) is conducted at an LHSV from about 5 hr −1  to about 15 hr −1 . 
     
     
         26 . The process of  claim 20 , wherein the decolorization catalyst comprises a noble metal and MCM-41. 
     
     
         27 . The process of  claim 26 , wherein the noble metal comprises platinum. 
     
     
         28 . The process of  claim 20 , wherein the second cloud point is about 10° C. to about 30° C. less than the first cloud point.