Hydroprocessing for distillate production

Abstract

Methods are provided for hydrotreating a feed to generate a product with a reduced or minimized aromatics content and/or an increased distillate product yield. A distillate boiling range feed having an elevated content of sulfur and/or nitrogen can be hydrotreated using at least two hydrotreating stages with intermediate separation to produce a hydrotreated distillate boiling range product with a reduced or minimized aromatics content. Additionally or alternately, a mixed metal catalyst formed from a suitable precursor can be used during the hydrotreating. A mixed metal catalyst formed from a suitable precursor can provide an unexpectedly superior activity for aromatic saturation. A still further unexpected benefic can be achieved by combining a multi-stage hydrotreating process with intermediate separation with hydrotreating in the presence of a mixed metal catalyst formed from a suitable precursor.

What is claimed is: 
     
         1 . A hydrotreating process comprising:
 reacting a feedstream having a sulfur content of at least about 3000 wppm and a T90 boiling point of about 900° F. (482° C.) or less in a first hydrotreating stage in the presence of a hydrogen-containing treat gas and in the presence of at least one first stage hydrotreating catalyst, the first hydrotreating stage being operated at first stage hydrotreating conditions, to produce a first liquid effluent having a sulfur content of about 5000 wppm or less, the sulfur content of the first liquid effluent being less than the sulfur content of the feedstream;   separating the first liquid effluent to produce a first vapor phase stream and a first liquid product stream;   reacting at least a portion of the first liquid product stream in a second hydrotreating stage in the presence of a hydrogen-containing treat gas and a second hydrotreating catalyst, the second hydrotreating stage being operated at second stage hydrotreating conditions to produce a second liquid effluent; and   separating the second liquid effluent to produce a second vapor phase stream and a second liquid product stream having a sulfur content of about 500 wppm or less,   wherein about 15 wt % or less of the feedstream is converted relative to a conversion temperature of 350° F. (177° C.) during the reacting in the first hydrotreating stage and the second hydrotreating stage.   
     
     
         2 . The process of  claim 1 , wherein the first liquid effluent has a sulfur content of at least about 1000 wppm. 
     
     
         3 . The process of  claim 1 , wherein a T90 boiling point of the first liquid product stream is about 800° F. (427° C.) or less. 
     
     
         4 . The process of  claim 1 , wherein a T10 boiling point of the feedstream is at least about 350° F. (177° C.), or wherein the T90 boiling point of the feedstream is about 850° F. (454° C.) or less, or a combination thereof. 
     
     
         5 . The process of  claim 1 ,
 wherein the first stage hydrotreating conditions are effective for conversion of about it 10 wt % or less of the feedstream relative to a conversion temperature of about 350° F. (177° C.), or   wherein the second stage hydrotreating conditions are effective for conversion of about 10 wt % or less of the feedstream relative to a conversion temperature of about 350° F. (177° C.), or   wherein about 10 wt % or less of the feedstream is converted relative to a conversion temperature of 350° F. (177° C.) during the reacting in the first hydrotreating stage and the second hydrotreating stage, or   a combination thereof.   
     
     
         6 . The process of  claim 1 , further comprising hydroprocessing at least a portion of the first liquid product stream in an intermediate hydrotreating stage. 
     
     
         7 . The process of  claim 1 , wherein the hydrotreating catalyst comprises Mo, W, or a combination thereof, and wherein the hydrotreating catalyst comprises Ni, Co, Fe, or a combination thereof, the hydrotreating catalyst optionally being a supported catalyst or optionally being a bulk catalyst. 
     
     
         8 . The process of  claim 7 , wherein the hydrotreating catalyst comprises i) about 1 wt % to about 40 wt % of the Mo, W, or a combination thereof, ii) wherein the hydrotreating catalyst comprises about 2 wt % to about 70 wt % of the Ni, Co, Fe, or a combination thereof, or both i) and ii). 
     
     
         9 . The process of  claim 1 , wherein the first stage hydrotreating conditions, the second stage hydrotreating conditions, or a combination thereof comprise temperatures of about 200° C. to about 450° C.; pressures of about 250 psig (1.8 MPag) to about 5000 psig (34.6 MPag); liquid hourly space velocities (LHSV) of about 0.1 hr −1  to about it 10 hr −1 ; and hydrogen treat rates of about 200 scf/B (35.6 m 3 /m 3 ) to about 10,000 scf/B (1781 m 3 /m 3 ). 
     
     
         10 . The process of any of the above claims, further comprising performing catalytic dewaxing, hydrofinishing, aromatic saturation, or a combination thereof on at least a portion of the second liquid product stream. 
     
     
         11 . The process of  claim 10 , wherein the catalytic dewaxing is performed at effective catalytic dewaxing conditions comprising temperatures of about 200° C. to about 450° C., hydrogen partial pressures of about 1.8 MPag to about 34.6 MPag (250 psig to 5000 psig), liquid hourly space velocities of from 0.05 h −1  to 10 h −1 , and hydrogen treat gas rates of about 35.6 m 3 /m 3  (200 SCF/B) to about 1781 m 3 /m 3  (10,000 scf/B). 
     
     
         12 . The process of  claim 10 , wherein the hydrofinishing is performed at effective hydrofinishing conditions comprising temperatures from about 125° C. to about 425° C., total pressures from about 500 psig (3.4 MPa) to about 3000 psig (20.7 MPa), liquid hourly space velocities from about 0.1 hr −1  to about 5 hr −1  LHSV, and hydrogen treat gas rates of from 500 to 5000 scf/B (89 to 890 m 3 /m 3 ). 
     
     
         13 . The process of  claim 10 , wherein the aromatic saturation is performed at effective aromatic saturation conditions comprising temperatures from about 200° C. to about 425° C., total pressures from about 500 psig (3.4 MPa) to about 3000 psig (20.7 MPa), liquid hourly space velocities from about 0.1 hr −1  to about 5 hr −1  LHSV, and hydrogen treat gas rates of from 500 to 5000 scf/B (89 to 890 m 3 /m 3 ). 
     
     
         14 . A hydrotreating process comprising:
 reacting a feedstream having a T90 boiling point of about 900° F. (482° C.) or less in a first hydrotreating stage in the presence of a hydrogen-containing treat gas and in the presence of at least one first stage hydrotreating catalyst, the first hydrotreating stage being operated at first stage hydrotreating conditions, to produce a first liquid effluent;   separating at least a portion of the first liquid effluent to produce a first vapor phase stream and a first liquid product stream, the first liquid product stream having a sulfur content of about 1000 wppm to about 20,000 wppm, the first liquid product stream having a) a T10 boiling point of at least about 350° F. (177° C.), b) a T90 boiling point of about 850° F. (454° C.) or less, or c) a combination thereof;   reacting at least a portion of the first liquid product stream in a second hydrotreating stage in the presence of a hydrogen-containing treat gas and a second hydrotreating catalyst, the second hydrotreating stage being operated at second stage hydrotreating conditions to produce a second liquid effluent, the second stage hydrotreating conditions being effective for conversion of about 10 wt % or less of the at least a portion of the first liquid product stream relative to a conversion temperature of about 350° F. (177° C.); and   separating at least a portion of the second liquid effluent to produce a second vapor phase stream and a second liquid product stream, the second liquid product stream having a sulfur content of about 100 wppm or less.   
     
     
         15 . The process of  claim 14 , wherein the first stage hydrotreating conditions, the second stage hydrotreating conditions, or a combination thereof comprise temperatures of about 200° C. to about 450° C.; pressures of about 250 psig (11.8 MPag) to about 5000 psig (34.6 MPag); liquid hourly space velocities (LHSV) of about 0.1 hr −1  to about 10 hr −1 ; and hydrogen treat rates of about 200 scf/B (35.6 m 3 /m 3 ) to about 10,000 scf/B (1781 m 3 /m 3 ). 
     
     
         16 . The process of  claim 14 , wherein a T90 boiling point of the first liquid product stream is about 800° F. (427° C.) or less. 
     
     
         17 . The process of  claim 14 , wherein a T10 boiling point of the feedstream is at least about 350° F. (177° C.), or wherein the T90 boiling point of the feedstream is about 850° F. (454° C.) or less, or a combination thereof. 
     
     
         18 . The process of  claim 14 ,
 wherein the first stage hydrotreating conditions are effective for conversion of about 10 wt % or less of the feedstream relative to a conversion temperature of about 350° F. (177° C.), or   wherein the second stage hydrotreating conditions are effective for conversion of about 10 wt % or less of the feedstream relative to a conversion temperature of about 350° F. (177° C.), or   wherein about 10 wt % or less of the feedstream is converted relative to a conversion temperature of 350° F. (177° C.) during the reacting in the first hydrotreating stage and the second hydrotreating stage, or   a combination thereof.   
     
     
         19 . The process of  claim 14 , further comprising hydroprocessing at least a portion of the first liquid product stream in an intermediate hydrotreating stage. 
     
     
         20 . The process of  claim 14 , further comprising performing catalytic dewaxing, hydrofinishing, aromatic saturation, or a combination thereof on at least a portion of the second liquid product stream.