Integrated hydrotreating process for the dual production of FCC treated feed and an ultra low sulfur diesel stream

• US 6,843,906 B1
• Filed: 05/17/2002
• Issued: 01/18/2005
• Est. Priority Date: 09/08/2000
• Status: Expired due to Fees

• Current Assignee: UOP Llc (Honeywell International Inc.)
• Original Assignee: UOP Llc (Honeywell International Inc.)
• Inventors: Eng, Odette T.
• Primary Examiner(s): Griffin, Walter D.
• Assistant Examiner(s): Nguyen, Tam
• Application Number:
  US10/151,077
• Time in Patent Office: 977 Days
• Field of Search: 208/208.R, 208/210, 208/211, 208/212, 208/213, 208/216.R, 208/217, 208/222
• US Class Current: 208/210
• CPC Class Codes: C10G 45/02 to eliminate hetero atoms without changing the skeleton of the hydrocarbon involved and without cracking into lower boiling hydrocarbons; Hydrofinishing
• CPC Class Codes: C10G 65/04 including only refining steps
• CPC Class Codes: C10G 69/04 including at least one step of catalytic cracking in the absence of hydrogen

Abstract

An integrated hydrotreating process which produces a high quality feed for the FCC to maintain sulfur in FCC gasoline to a level lower than 30 ppm from a high boiling feedstock and an ultra low sulfur diesel stream preferably less than 10 ppm from a cracked stock diesel boiling material. The high boiling feedstock is firstly hydrotreated to reduce the concentration of heterogeneous compounds which produces lower boiling hydrocarbonaceous compounds boiling in the diesel range. The resulting hydrocarbonaceous compounds boiling in the diesel range together with other cracked material in the diesel boiling range are further hydrotreated in a second hydrotreating zone to meet ultra low sulfur diesel specifications and high cetane index.

Claims

1. An integrated hydrotreating process for the desulfurization of a fluid catalytic cracker (FCC) feedstock to achieve low sulfur specifications in FCC produced gasoline and the simultaneous production of an ultra low sulfur diesel stream which process comprises:

a) reacting a hydrocarbonaceous feedstock having a majority boiling at a temperature greater than about 371°

C. (700°

F.) and hydrogen in a first denitrification and desulfurization reaction at reaction zone conditions including a temperature from about 204°

C. (400°

F.) to 426°

C. (800°

F.) and a pressure from about 3.5 MPa (500 psig) to about 17.3 MPa (2500 psig) with a catalyst to reduce the sulfur content of the feedstock and to convert less than about 20 volume percent of the feedstock to lower boiling hydrocarbons;

b) passing a denitrification and desulfurization reaction zone effluent to a first vapor-liquid separator maintained at a temperature from about 149°

C. (300°

F.) to about 426°

C. (800°

F.) to produce a first vapor stream boiling in a range below that of the feedstock and containing diesel boiling range hydrocarbons, and a first liquid stream;

c) cooling and partially condensing the first vapor stream to produce in a second vapor-liquid separator, a hydrogen-rich gaseous stream containing hydrogen sulfide and a second liquid stream comprising diesel boiling range hydrocarbons;

d) passing the hydrogen-rich gaseous stream containing hydrogen sulfide to an acid gas scrubbing zone to produce a hydrogen-rich gaseous stream having a reduced concentration of hydrogen sulfide;

e) passing the first liquid stream to a flash zone to remove dissolved hydrogen and normally gaseous hydrocarbons and then to a fractionation zone;

f) passing at least a portion of the second liquid stream to the fractionation zone;

g) removing a third liquid stream containing diesel boiling range hydrocarbons from the fractionation zone and passing the third liquid stream and hydrogen to a second denitrification and desulfurization zone to produce a fourth liquid stream containing reduced sulfur content, diesel boiling range hydrocarbons;

h) passing at least a portion of the hydrogen-rich gaseous stream having a reduced concentration of hydrogen sulfide to the first and the second desulfurization reaction zones; and

i) recovering a fluid catalytic cracking feedstock having a sulfur content lower than the feedstock and having a majority boiling at a temperature greater than about 371°

C. (700°

F.).

2. The process of claim 1 wherein a second feedstock comprising diesel boiling range hydrocarbons is introduced into the second denitrification and desulfurization zone.

3. An integrated hydrotreating process for the desulfurization of a fluid catalytic cracker (FCC) feedstock to achieve low sulfur specifications in FCC produced gasoline and the simultaneous production of an ultra low sulfur diesel stream which process comprises:

a) reacting a first hydrocarbonaceous feedstock having a majority boiling at a temperature greater than about 371°

C. (700°

F.) and hydrogen in a first denitrification and desulfurization reaction at reaction zone conditions including a temperature from about 204°

C. (400°

F.) to 426°

C. (800°

F.) and a pressure from about 3.5 MPa (500 psig) to about 17.3 MPa (2500 psig) with a catalyst to reduce the sulfur content of the feedstock and to convert less than about 20 volume percent of the feedstock to lower boiling hydrocarbons;

b) passing a denitrification and desulfurization reaction zone effluent to a first vapor-liquid separator maintained at a temperature from about 149°

C. (300°

F.) to about 426°

C. (800°

F.) to produce a first vapor stream boiling in a range below that of the feedstock and containing diesel boiling range hydrocarbons, and a first liquid stream;

c) cooling and partially condensing the first vapor stream to produce in a second vapor-liquid separator, a hydrogen-rich gaseous stream containing hydrogen sulfide and a second liquid stream comprising diesel boiling range hydrocarbons;

d) passing the hydrogen-rich gaseous stream containing hydrogen sulfide to an acid gas scrubbing zone to produce a hydrogen-rich gaseous stream having a reduced concentration of hydrogen sulfide;

e) passing the first liquid stream to a flash zone to remove dissolved hydrogen and normally gaseous hydrocarbons and then to a fractionation zone;

f) passing at least a portion of the second liquid stream to the fractionation zone;

g) removing a third liquid stream containing diesel boiling range hydrocarbons from the fractionation zone and passing the third liquid stream, a second feedstock comprising diesel boiling range hydrocarbons and hydrogen to a second denitrification and desulfurization zone to produce a fourth liquid stream containing reduced sulfur content, diesel boiling range hydrocarbons;

h) passing at least a portion of the hydrogen-rich gaseous stream having a reduced concentration of hydrogen sulfide to the first and the second desulfurization reaction zones; and

i) recovering a fluid catalytic cracking feedstock having a sulfur content lower than the feedstock and having a majority boiling at a temperature greater than about 371°

C. (700°

F.).