Method and apparatus for removing H;S and moisture from fractionator overhead naphtha

• US 9,181,501 B2
• Filed: 08/17/2012
• Issued: 11/10/2015
• Est. Priority Date: 08/17/2012
• Status: Active Grant

• Current Assignee: UOP Llc (Honeywell International Inc.)
• Original Assignee: UOP Llc (Honeywell International Inc.)
• Inventors: Vaidyanathan, Krishnan, Pandranki, Venkat Ram Naidu
• Primary Examiner(s): Singh, Prem C
• Assistant Examiner(s): Doyle, Brandi M
• Application Number:
  US13/588,065
• Publication Number:
  US 20140048446A1
• Time in Patent Office: 1,180 Days
• Field of Search: 208/95, 208/97, 208/100, 208/102, 208/103, 208/105, 208/212, 210/767, 210/806, 423/563, 423/564
• US Class Current: 1/1
• CPC Class Codes: C10G 2300/1044 Heavy gasoline or naphtha having a boiling range of about 100 - 180 °C
• CPC Class Codes: C10G 2300/207 Acid gases, e.g. H2S, COS, SO2, HCN
• CPC Class Codes: C10G 70/041 by distillation
• CPC Class Codes: C10G 70/06 by gas-liquid contact

Abstract

Methods and apparatus for making naphtha substantially free of H₂S are described. The method includes stripping an incoming stream containing naphtha and H₂S in a fractionator into at least an overhead stream containing the naphtha and H₂S and a bottoms stream, and introducing the overhead stream from the fractionator into a separator to form a naphtha stream substantially free of H₂S and an overhead stream containing H₂S.

Claims

1. A method of making naphtha substantially free of H₂S comprising:

stripping an incoming stream containing naphtha and a level of H₂S that is less than about 10 wppb in a fractionator into at least a fractionator overhead stream containing the naphtha and H₂S and a bottoms stream;

separating the fractionator overhead stream into overhead gas stream and a fractionator overhead liquid naphtha stream having a level of H₂S that is at least about 50 wppm; and

introducing the fractionator overhead liquid naphtha stream into a separator comprising a coalescer or a vacuum dryer to form a naphtha stream substantially free of H₂S and a stream containing H₂S.

2. The method of claim 1 wherein the incoming stream containing naphtha and H₂S is produced by stripping a hydroprocessed product in a stripper column into a stripper column overhead stream and the incoming stream containing the naphtha and H₂S.

3. The method of claim 2 wherein the hydroprocessed product is produced by reacting a hydrocarbon stream having a boiling point between about 240°

C. and about 600°

C. in a hydroprocessing zone under hydroprocessing conditions.

4. The method of claim 2 wherein the separator is a vacuum dryer and further comprising introducing a portion of the vacuum dryer overhead stream into the stripper column.

5. The method of claim 2 wherein the stripper column overhead stream comprises at least one of light naphtha, light petroleum gas, light hydrocarbons, and H₂S.

6. The method of claim 1 wherein the incoming stream comprises a mixture of light naphtha, heavy naphtha, and heavy hydrocarbons.

7. The method of claim 1 further comprising recovering the naphtha stream substantially free of H₂S.

8. The method of claim 1 wherein the separator is a coalescer, wherein stripping the incoming stream containing naphtha and H₂S comprises steam stripping the incoming stream containing naphtha and H₂S, and wherein the fractionator overhead liquid naphtha stream is introduced into the coalescer.

9. The method of claim 1 wherein stripping the incoming stream containing naphtha and H₂S in the fractionator into at least the fractionator overhead liquid naphtha stream containing the naphtha and H₂S and the bottoms stream further comprises stripping the incoming stream containing naphtha and H₂S in the fractionator into at least the overhead stream containing the naphtha and H₂S and the bottoms stream, a light gas oil stream, and a heavy gas oil stream.

10. A method of making naphtha substantially free of H₂S comprising:

reacting a hydrocarbon stream having a boiling point between about 240°

C. and about 600°

C. in a hydroprocessing zone under hydroprocessing conditions to form a hydroprocessed product;

stripping the hydroprocessed product in a stripper column into a stripper column overhead stream and a stripper column bottoms stream containing naphtha and a level of H₂S that is less than about 10 wppb;

stripping the stripper column bottoms stream in a fractionator into at least a fractionator overhead stream containing the naphtha and H₂S and a fractionator bottoms stream;

separating the fractionator overhead stream into overhead gas stream and a fractionator overhead liquid naphtha stream having a level of H₂S that is at least about 50 wppm; and

introducing the fractionator overhead liquid naphtha stream into a separator to form a naphtha stream substantially free of H₂S and a stream containing H₂S.

11. The method of claim 10 further comprising recovering the naphtha stream substantially free of H₂S.

12. The method of claim 10 wherein the separator is a vacuum dryer and further comprising introducing a portion of the vacuum dryer overhead stream into the stripper column.

13. The method of claim 10 wherein the stripper column bottoms stream comprises a mixture of light naphtha, heavy naphtha, and heavy hydrocarbons.

14. The method of claim 10 wherein stripping the stripper column bottoms stream in the fractionator into at least the fractionator overhead liquid naphtha stream containing the naphtha and H₂S and the fractionator bottoms stream further comprises stripping the stripper column bottoms stream in the fractionator into at least the fractionator overhead liquid naphtha stream containing the naphtha and H₂S and the fractionator bottoms stream, a light gas oil stream, and a heavy gas oil stream.

15. The method of claim 10 wherein the separator is a coalescer, wherein stripping the incoming stream containing naphtha and H₂S comprises steam stripping the incoming stream containing naphtha and H₂S, and wherein the fractionator overhead liquid naphtha stream is introduced into the coalescer.