SG194628A1

SG194628A1 - Methods for recovering hydrogen from isomerizing and reforming of hydrocarbons

Info

Publication number: SG194628A1
Application number: SG2013079330A
Authority: SG
Inventors: David James Schecterle; William Yanez
Original assignee: Uop Llc
Priority date: 2011-08-19
Filing date: 2011-08-19
Publication date: 2013-12-30
Also published as: KR20140017685A; ZA201308385B; RU2013157344A; MY160208A; WO2013028160A1; CN103619787A; BR112013028031A2

Abstract

Embodiments of methods for recovering hydrogen from isomerizing and reforming of hydrocarbons are provided. The method comprises the steps of combining a HCl-scrubbed, isomerization-zone net gas stream that comprises hydrogen and C6- hydrocarbons with a reforming-zone net gas stream that comprises hydrogen and C6- hydrocarbons to form a combined net gas stream that comprises hydrogen and light end hydrocarbons. The light end hydrocarbons are extracted from the combined net gas stream in a re-contacting zone using a reforming-zone product stream that comprises C5+ hydrocarbons to form a hydrogen-rich net gas stream.

Description

METHODS FOR RECOVERING HYDROGEN FROM ISOMERIZING AND

REFORMING OF HYDROCARBONS

FIELD OF THE INVENTION

[0001] The present invention relates generally to methods for isomerizing and reforming of hydrocarbons, and more particularly relates to methods for recovering hydrogen from isomerizing and reforming of hydrocarbons.

BACKGROUND OF THE INVENTION

[0002] High octane gasoline is needed for modern gasoline engines. Previously, octane numbers were often improved by incorporating various lead-containing additives into the gasoline. As lead-containing additives have been phased out of gasoline for environmental reasons, it has become increasingly necessary to rearrange the structure of the hydrocarbons used in gasoline blending to achieve higher octane ratings. Catalytic reforming and catalytic isomerization of hydrocarbons are two processes widely used by refiners for upgrading the octane ratings of gasoline.

[0003] In catalytic reforming, a hydrocarbon feedstock of, for example, Cs hydrocarbons to about Cj; hydrocarbons, is contacted with a reforming catalyst to convert at least a portion of the heavier hydrocarbons to aromatic hydrocarbons to increase the octane content of gasoline. The catalytic reforming of the heavier hydrocarbons also produces significant quantities of hydrogen, which has become very important to many refiners and can be used, for example, for hydrotreating to reduce sulfur levels in gasoline and other fuels. To recover this hydrogen, many refineries use catalytic reforming processes that have a re-contacting zone for sequestering hydrogen from the reforming zone effluent.

Unfortunately, the quantities of hydrogen that are typically recovered in catalytic reforming processes are often insufficient to meet the hydrogen demands in many refineries.

[0004] In catalytic isomerization, a light hydrocarbon fraction containing normal paraffins of, for example, butane, pentane, and/or hexane, is contacted with an isomerization catalyst in the presence of a stoichiometric excess of hydrogen to form an effluent that is separated into an isomerization product stream and an isomerization net gas stream. The isomerization product stream contains branched paraffins, such as iso-butane, branched pentane, and/or branched hexane that are used to increase the octane content of gasoline. The isomerization net gas stream contains hydrogen and light end hydrocarbons, e.g., Cy to Cs and possibly some Cg hydrocarbons. Unfortunately, many refineries burn the isomerization net gas stream as fuel gas because the equipment and operating cost associated with recovering hydrogen from this stream is prohibitively high despite their unmet need for hydrogen.

[0005] Accordingly, it is desirable to provide methods for recovering hydrogen from hydrocarbon isomerization and reforming processes that preferably increase the quantities of recovered hydrogen compared to conventional processes with minimal additional equipment and cost. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent Detailed Description of the

Invention and the appended Claims, when taken in conjunction with the accompanying drawings and this Background of the Invention.

SUMMARY OF THE INVENTION

[0006] Methods for recovering hydrogen from isomerizing and reforming of hydrocarbons are provided herein. In accordance with an exemplary embodiment, a method for recovering hydrogen from isomerizing and reforming of hydrocarbons comprises combining a HCl-scrubbed, isomerization-zone net gas stream that comprises hydrogen and Cg- hydrocarbons with a reforming-zone net gas stream that comprises hydrogen and Cs- hydrocarbons to form a combined net gas stream that comprises hydrogen and light end hydrocarbons. The light end hydrocarbons are extracted from the combined net gas stream in a re-contacting zone using a reforming-zone product stream that comprises Cs+ hydrocarbons to form a hydrogen-rich net gas stream.

[0007] In accordance with another exemplary embodiment, a method for recovering hydrogen from isomerizing and reforming of hydrocarbons is provided. The method comprises contacting a paraffin feed stream with a chloride-promoted isomerization catalyst in the presence of hydrogen to form an isomerization reactor-zone effluent. The isomerization reactor-zone effluent is separated into an isomerization-zone product stream that comprises branched paraffins and a isomerization-zone net gas stream that comprises hydrogen, chloride-containing compounds including HCI, and C¢- hydrocarbons. At least a portion of the chloride-containing compounds is removed from the isomerization-zone net gas stream to form an HCl-scrubbed, isomerization-zone net gas stream. Water is removed from the HCl-scrubbed, isomerization-zone net gas stream to form a water- depleted, HCl-scrubbed, isomerization-zone net gas stream. The water-depleted, HCI- scrubbed, isomerization-zone net gas stream is combined with a reforming-zone net gas stream that comprises hydrogen and Cs- hydrocarbons to form a combined net gas stream that comprises hydrogen and light end hydrocarbons. The combined net gas stream is compressed with a compressor that is upstream from a re-contacting zone to form a compressed combined net gas stream. The compressed combined net gas stream and a reforming-zone product stream that comprises Cs+ hydrocarbons including aromatics are advanced through the re-contacting zone. The light end hydrocarbons are extracted from the compressed combined net gas stream in the re-contacting zone using the reforming- zone product stream to form a hydrogen-rich net gas stream and an aromatics-containing product stream.

[0008] In accordance with another exemplary embodiment, a method for recovering hydrogen from isomerizing and reforming of hydrocarbons is provided. The method comprises contacting a paraffin feed stream with a chloride-promoted isomerization catalyst in the presence of hydrogen to form an isomerization reactor-zone effluent. The isomerization reactor-zone effluent is separated into an isomerization-zone product stream that comprises branched paraffins and a isomerization-zone net gas stream that comprises hydrogen, chloride-containing including HCl, and Cs- hydrocarbons. At least a portion of the chloride-containing compounds is removed from the isomerization-zone net gas stream to form an HCl-scrubbed, isomerization-zone net gas stream. Water is removed from the

HCl-scrubbed, isomerization-zone net gas stream to form a water-depleted, HCl-scrubbed, isomerization-zone net gas stream. The water-depleted, HCl-scrubbed, isomerization-zone net gas stream is combined with a reforming-zone net gas stream that comprises hydrogen and Cs- hydrocarbons in a re-contacting zone to form a combined net gas stream that comprises hydrogen and light end hydrocarbons. The combined net gas stream is compressed with a compressor that is in the re-contacting zone to form a compressed combined net gas stream. A reforming-zone product stream that comprises Cs+ hydrocarbons including aromatics is introduced to the re-contacting zone. The light end hydrocarbons is extracted from the compressed combined net gas stream in the re- contacting zone using the reforming-zone product stream to form a hydrogen-rich net gas stream and an aromatics-containing product stream.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Embodiments of the present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein:

[0010] FIG. 1 schematically illustrates an apparatus including a paraffin isomerization section and a hydrocarbon reforming section in accordance with an exemplary embodiment;

[0011] FIG. 2 schematically illustrates a paraffin isomerization section of the apparatus depicted in FIG. 1;

[0012] FIG. 3 schematically illustrates a hydrocarbon reforming section of the apparatus depicted in FIG. 1; and

[0013] FIG. 4 schematically illustrates a re-contacting zone of the hydrocarbon reforming section depicted in FIG. 3.

DETAILED DESCRIPTION

[0014] The following Detailed Description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding Description of

Related Art or the following Detailed Description.

[0015] Various embodiments contemplated herein relate to methods for recovering hydrogen from isomerizing and reforming of hydrocarbons. Unlike the prior art, the exemplary embodiments taught herein combine an isomerization-zone net gas stream from a paraffin isomerization section with a reforming-zone net gas stream from a hydrocarbon reforming section. Prior to combining the two streams, the isomerization-zone net gas stream is scrubbed to remove chloride-containing compounds including HCI to protect the downstream equipment. The reforming-zone net gas stream comprises hydrogen and Co- hydrocarbons and the isomerization-zone net gas stream comprises hydrogen and Ce or lighter hydrocarbons. As used herein, Cx means hydrocarbon molecules that have “X” number of carbon atoms, C+ means hydrocarbon molecules that have “X” and/or more than “X” number of carbon atoms, and C- means hydrocarbon molecules that have “X” and/or less than “X” number of carbon atoms. “Cy and lighter and hydrocarbons” means hydrocarbon molecules having “X” and less than “X” number of carbon atoms. The two streams combine to form a combined net gas stream that comprises hydrogen and light end hydrocarbons. The combined net gas stream is compressed via a compressor in the hydrocarbon reforming section to form a compressed combined net gas stream. The compressed combined net gas stream is passed through a re-contacting zone of the hydrocarbon reforming section. In the re-contacting zone, the light end hydrocarbons are extracted from the combined net gas stream using a reforming-zone product stream that comprises Cs+ hydrocarbons to form a hydrogen-rich net gas stream. Overall hydrogen recovery is improved for isomerizing and reforming of hydrocarbons because the hydrogen-rich net gas stream includes hydrogen not only from the reforming-zone net gas stream but also from the isomerization-zone net gas stream. Moreover, the additional hydrogen recovered from the paraffin isomerization section is preferably accomplished with minimal additional equipment and cost because the hydrogen extracted from the isomerization-zone net gas stream is done using the hydrocarbon reforming section’s existing equipment and re-contacting zone.

[0016] Referring to FIG. 1, a schematic depiction of an apparatus 10 for removing hydrogen from isomerizing and reforming of hydrocarbons in accordance with an exemplary embodiment is provided. The apparatus 10 comprises a paraffin isomerization section 12 and a hydrocarbon reforming section 14. The paraffin isomerization section 12 is utilized for a paraffin isomerization process that converts normal paraffins to branched paraffins. The paraffin isomerization section 12 comprises a reaction zone 18 and a stabilizing-scrubbing zone 20. The hydrocarbon reforming section 14 is utilized for a hydrocarbon reforming process that converts a Cs to C;; hydrocarbon feedstock into an aromatics-containing reformate for gasoline.

[0017] FIG. 2 is a detailed illustration of the paraffin isomerization section 12 in accordance with an exemplary embodiment. The reaction zone 18 and the stabilizing-

scrubbing zone 20 include a reactor 22 and a distillation column 24, respectively, that are in fluid communication. A paraffin feed 26 is passed through a dryer 28 for removing water and to form a dried paraffin feed 29. In one embodiment, the paraffin feed 26 is rich in C4 hydrocarbons, such as n-butane and may also contain relatively small amounts of iso-butane, pentane, and heavier materials. In another embodiment, the paraffin feed 26 is rich in Cs and/or Cg hydrocarbons, such as normal pentane and normal hexane. A hydrogen-containing gas feed 30 is passed through a dryer 32 for removing water and is combined with the dried paraffin feed 29 to form a combined stream 34. The combined stream 34 is passed through a heat exchanger 36 and a heater 38, and is introduced to the reactor 22. In an exemplary embodiment, the reactor 22 is a fixed-bed catalytic reactor operating at a temperature of about 90 to about 210°C and contains a high-activity chloride-promoted catalyst that is effective to isomerize the normal paraffins to branched paraffins (e.g., iso-butane, branched pentane, branched hexane, or combinations thereof) to produce an isomerization reaction-zone effluent 40. The isomerization reaction-zone effluent 40 contains the branched paraffins, other hydrocarbons, and chloride-containing compounds including HCL.

[0018] The isomerization reaction-zone effluent 40 is passed through the heat exchanger 36 and is cooled to a temperature of from about 65 to about 150°C. The isomerization reaction-zone effluent 40 then is introduced to the distillation column 24. The distillation column 24 separates the isomerization reaction-zone effluent 40 into an isomerization product stream 42 and a liquefied petroleum gas (LPG) stream 44. The isomerization product stream 42 contains branched paraffins. A portion of the isomerization product stream 42 may be passed through a heater 45, heated to about 140 to about 200°C, and recycled back to the distillation column 24. The LPG stream 44 is passed through a cooler 46, cooled down to about 0 to about 55°C, and is introduced to a vent drum 48. A liquid stream 50 is removed from the vent drum 48 and is passed through a pump 52 to the distillation column 24 for reflux.

[0019] Light volatiles are removed from the vent drum 48 and form an isomerization- zone net gas stream 54. The isomerization-zone net gas stream 54 is rich in hydrogen and also contains some Cj or lighter hydrocarbons, and chloride-containing compounds including HCL. In an exemplary embodiment, the isomerization-zone net gas stream 54 is vented from the vent drum 48 at a pressure of from about 1,000 to about 2,000 kPa. As illustrated, the isomerization-zone net gas stream 54 is passed through a scrubber 56 to remove at least a portion of the chloride-containing compounds including HCI to form a

HCl-scrubbed, isomerization-zone net gas stream 58 that contains water absorbed from the scrubber 56. The HCl-scrubbed, isomerization-zone net gas stream 58 is passed through a drying zone 59 that contains one or more dryers to remove water and form a water- depleted, HCl-scrubbed, isomerization-zone net gas stream 60. As illustrated in FIG. 1, the water-depleted, HCl-scrubbed, isomerization-zone net gas stream 60 is introduced to the hydrocarbon reforming section 14.

[0020] Referring to FIG. 3, a schematic depiction of the hydrocarbon reforming section 14 of the apparatus 10 in accordance with an exemplary embodiment is provided. A reforming-zone feedstock 62 containing from Cs to about C;; hydrocarbons with a boiling point range of, for example, from about 80 to about 205°C is introduced to a combined feed exchanger 64. The combined feed exchanger 64 operates to exchange heat between a reforming-zone effluent 66 and the reforming-zone feedstock 62. A heated reforming- zone feed stream 68 is withdrawn from the combined feed exchanger 64 and is passed through a heater 70, which is capable of interstage heating of multiple streams, to form a fully heated reforming-zone feed stream 72. The fully heated reforming-zone feed stream 72 is passed to a first stage of a reforming reactor 74 that contains a reforming catalyst as is well known in the art. As illustrated, the reforming reactor 74 is configured for continuous catalyst regeneration where spent catalyst is continuously removed from the reforming reactor 74 via line 76 and passed to a regeneration zone 78 for regeneration.

Regenerated catalyst from the regeneration zone 78 is introduced into the reforming reactor 74 via line 80.

[0021] At cach stage of the reforming reactor 74, a reaction mixture is conducted from the reforming reactor 74 to the heater 70 and then the heated reaction mixture is returned to the reforming reactor 74. A reforming-zone effluent 66 is formed in the reforming reactor 74 and contains hydrogen, a product comprising Cs+ hydrocarbons including aromatics, and lighter hydrocarbons. The reforming-zone effluent 66 is passed along to the combined feed exchanger 64 where heat from the reforming-zone effluent 66 is exchanged with the reforming-zone feedstock 62 to form a partially cooled reforming- zone effluent 82.

[0022] The partially cooled reforming-zone effluent 82 is passed through a cooler 84 and introduced to a reforming-zone product separator 86. The reforming-zone product separator 86 separates the reforming-zone effluent into a reforming zone product stream 88 comprising Cs+ hydrocarbons, and a reforming-zone net gas stream 90 comprising hydrogen and Cs- hydrocarbons. Conditions for operating the reforming-zone product separator include pressures of from about 241 to about 1,400 kPa. As illustrated, the reforming-zone net gas stream 90 is divided into a first portion 92 that is passed through a recycle compressor 94 to combine with the reforming-zone feedstock 62, and a second portion 96 that is passed along to a suction vessel 98 for a first stage net gas compressor 100. As illustrated, the first stage net gas compressor 100 is upstream from a re-contacting zone 102.

[0023] The water-depleted, HCl-scrubbed, isomerization zone net gas stream 60 is combined with the reforming-zone net gas stream 90 to form a combined net gas stream that comprises hydrogen and light end hydrocarbons, such as Cs- hydrocarbons and possibly some Cg hydrocarbons. In an exemplary embodiment, the water-depleted, HCI- scrubbed, isomerization zone net gas stream 60 is combined with the reforming-zone net gas stream 90 and the combined net gas stream is introduced to the first stage net gas compressor 100 via the suction vessel 98 to form a compressed gas stream 104. The compressed gas stream 104 preferably has a pressure of from about 1,000 to about 3,000 kPa and is introduced to the re-contacting zone 102 for further separation.

[0024] Referring to FIG. 4, a schematic depiction of the re-contacting zone 102 in accordance with an exemplary embodiment is provided. The reforming-zone product stream 88 is introduced to the re-contacting zone 102 and is combined with a compressed gas stream 106 to form a combined stream 109. The compressed gas stream 106 is formed from a gas stream 107 from a first stage re-contacting drum 110 after being passed through the second stage compressor 108. As will be discussed in further detail below, the gas stream 107 is formed from the reforming-zone net gas stream 90 or the combined net gas stream (i.e. combined net gas streams 90 and 60) and accordingly, is hydrogen rich with some low end hydrocarbons, such as Cs- hydrocarbons. The compressed gas stream 106 preferably has a pressure of from about 3,000 to about 6,000 kPa.

[0025] The combined stream 109 is passed through a heat exchanger 112 to adjust the temperature to about -15 to about 52°C and is introduced to a second stage re-contacting drum 114. In the second stage re-contacting drum 114, the liquid from the reforming-zone product stream 88 extracts low end hydrocarbons from the gas stream 107 to form a hydrogen-rich net gas stream 116 and a first-contacted, reforming-zone product stream 118. The first-contacted, reforming-zone product stream 118 is combined with the compressed gas stream 104 to form a combined stream 120. The combined stream 120 is passed through a heat exchanger 122 to adjust the temperature to about -15 to about 52°C and is introduced to the first stage re-contacting drum 110. In the first stage re-contacting drum 110, the liquid from the first-contacted, reforming-zone product stream 118 extracts low end hydrocarbons from the combined net gas stream to form the gas stream 107 and an aromatics-containing effluent 124. The hydrogen-rich net gas stream 116 may optionally be passed through a chloride treater 126 to remove any chloride-containing compounds.

[0026] In an alternative embodiment, the combined net gas stream is formed in the re- contacting zone 102, such as, for example, between the first stage re-contacting drum 110 and the second stage compressor 108. In particular, the water-depleted, HCl-scrubbed, isomerization zone net gas stream 60 may be passed along line 61 and combined with the reforming-zone net gas stream 90 downstream from the first stage re-contacting drum 110 but upstream from the second stage compressor 108 to form the gas stream 107. As discussed above, the gas stream 107 is compressed in the second stage compressor 108, combined with the reforming-zone product stream 88, and introduced to the second stage re-contacting drum 114 to form the hydrogen-rich net gas stream 116.

[0027] Referring back to FIG. 3, the aromatics-containing effluent 124 is passed through a heat exchanger 132 to adjust the temperature to about 93 to about 204°C and is introduced to a reforming-zone stabilizer 128. The reforming-zone stabilizer 128 removes light end hydrocarbons from the aromatics-containing effluent 124 to form a stabilized aromatics-containing reformate 130 that is passed through the heat exchanger 132, and a light ends gas stream 134.

[0028] Accordingly, methods for recovering hydrogen from isomerizing and reforming of hydrocarbons have been described. Unlike the prior art, the exemplary embodiments taught herein combine an isomerization-zone net gas stream from a paraffin isomerization section with a reforming-zone net gas stream from a hydrocarbon reforming section. The reforming-zone net gas stream comprises hydrogen and Cg- hydrocarbons and the isomerization-zone net gas stream comprises hydrogen and Cs or lighter hydrocarbons.

The two streams combine to form a combined net gas stream that comprises hydrogen and light end hydrocarbons. The combined net gas stream is compressed via a compressor in the hydrocarbon reforming section to form a compressed combined net gas stream. The compressed combined net gas stream is passed through a re-contacting zone of the hydrocarbon reforming section. In the re-contacting zone, the light end hydrocarbons are extracted from the combined net gas stream using a reforming-zone product stream that comprises Cs+ hydrocarbons to form a hydrogen-rich net gas stream. Overall hydrogen recovery is improved for isomerizing and reforming of hydrocarbons because the hydrogen-rich net gas stream includes hydrogen not only from the reforming-zone net gas stream but also from the isomerization-zone net gas stream. Moreover, the additional hydrogen recovered from the paraffin isomerization section is preferably accomplished with minimal additional equipment and cost because the hydrogen extracted from the isomerization-zone net gas stream is done using the hydrocarbon reforming section’s existing equipment and re-contacting zone.

[0029] While at least one exemplary embodiment has been presented in the foregoing

Detailed Description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing Detailed Description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended Claims and their legal equivalents.

Claims

CLAIMS What is claimed is:

I. A method for recovering hydrogen from isomerizing and reforming of hydrocarbons, the method comprising the steps of: combining a HCl-scrubbed, isomerization-zone net gas stream that comprises hydrogen and Cs- hydrocarbons with a reforming-zone net gas stream that comprises hydrogen and Ce- hydrocarbons to form a combined net gas stream that comprises hydrogen and light end hydrocarbons; and extracting the light end hydrocarbons from the combined net gas stream in a re-contacting zone using a reforming-zone product stream that comprises Cs+ hydrocarbons to form a hydrogen-rich net gas stream.
2. The method according to claim 1, further comprising the steps of: introducing a paraffin feed stream comprising Cs hydrocarbons, Cg hydrocarbons, or combinations thereof to an isomerization-zone operating at isomerization conditions effective to form a isomerization-zone net gas stream; and removing chloride-containing compounds including HCI from the isomerization-zone net gas stream to form the HCl-scrubbed, isomerization-zone net gas stream.
3. The method according to claim 1, further comprising the steps of: introducing a paraffin feed stream comprising C4 hydrocarbons to an isomerization-zone operating at isomerization conditions effective to form a isomerization-zone net gas stream; and removing chloride-containing compounds including HCI from the isomerization-zone net gas stream to form the HCl-scrubbed, isomerization-zone net gas stream.
4. The method according to claim 1, further comprising the step of removing water from the HCl-scrubbed, isomerization-zone net gas stream prior to the step of combining.
5. The method according to claim 1, further comprising the step of compressing the combined net gas stream to form a compressed combined net gas stream, and wherein the step of extracting includes extracting the light end hydrocarbons from the compressed combined net gas stream.
6. The method according to claim 5, wherein the re-contacting zone comprises a plurality of re-contacting drums for separating the light end hydrocarbons from the combined net gas stream, the plurality of re-contacting drums including a first stage re-contacting drum and a second stage re-contacting drum that is downstream from the first stage re-contacting drum, and wherein the step of extracting includes combining the compressed combined net gas stream with the reforming-zone product stream upstream from the first stage re-contacting drum to form a combined net gas-product stream that is introduced to the first stage re-contacting drum.
7. The method according to claim 6, wherein the step of compressing includes compressing the combined net gas stream with a compressor that is upstream from the first stage re-contacting drum.
8. The method according to claim 5, wherein the re-contacting zone comprises a plurality of re-contacting drums for separating the light end hydrocarbons from the combined net gas stream, the plurality of re-contacting drums including a first stage re-contacting drum and a second stage re-contacting drum that is downstream from the first stage re-contacting drum, and wherein the step of extracting includes combining the compressed combined net gas stream with the reforming-zone product stream upstream from the second stage re-contacting drum but downstream from the first stage re-contacting drum to form a combined net gas- product stream that is introduced to the second stage re-contacting drum.
9. The method according to claim 8, wherein the step of compressing includes compressing the combined net gas stream with a compressor that is downstream from the first stage re-contacting drum but upstream from the second stage re- contacting drum.
10. The method according to claim 1, further comprising the step of introducing the hydrogen-rich net gas stream to a chloride treater to remove chloride-containing compounds.
11. A method for recovering hydrogen from isomerizing and reforming of hydrocarbons, the method comprising the steps of: contacting a paraffin feed stream with a chloride-promoted isomerization catalyst in the presence of hydrogen to form an isomerization reactor-zone effluent; separating the isomerization reactor-zone effluent into an isomerization- zone product stream that comprises branched paraffins and a isomerization-zone net gas stream that comprises hydrogen, chloride-containing compounds including HCI, and Cs- hydrocarbons; removing at least a portion of the chloride-containing compounds from the isomerization-zone net gas stream to form an HCl-scrubbed, isomerization-zone net gas stream; removing water from the HCl-scrubbed, isomerization-zone net gas stream to form a water-depleted, HCl-scrubbed, isomerization-zone net gas stream; combining the water-depleted, HCl-scrubbed, isomerization-zone net gas stream with a reforming-zone net gas stream that comprises hydrogen and Ce- hydrocarbons to form a combined net gas stream that comprises hydrogen and light end hydrocarbons; compressing the combined net gas stream with a compressor that is upstream from a re-contacting zone to form a compressed combined net gas stream; advancing the compressed combined net gas stream and a reforming-zone product stream that comprises Cst+ hydrocarbons including aromatics through the re-contacting zone; and extracting the light end hydrocarbons from the compressed combined net gas stream in the re-contacting zone using the reforming-zone product stream to form a hydrogen-rich net gas stream and an aromatics-containing product stream.
12. The method according to claim 11, wherein the step of contacting includes contacting the paraffin feed stream that comprises Cs hydrocarbons, Cs hydrocarbons, or combinations thereof with the chloride-promoted isomerization catalyst.
13. The method according to claim 11, wherein the step of contacting includes contacting the paraffin feed stream that comprises C4 hydrocarbons with the chloride-promoted isomerization catalyst.
14. The method according to claim 11, further comprising the step of introducing the aromatics-containing product stream to a stabilizer to remove Cs- hydrocarbons and form a stabilized Cs+, aromatics-containing product.
15. The method according to claim 11, further comprising the step of introducing the hydrogen-rich net gas stream to a chloride treater to remove chloride compounds.
16. A method for recovering hydrogen from isomerizing and reforming of hydrocarbons, the method comprising the steps of: contacting a paraffin feed stream with a chloride-promoted isomerization catalyst in the presence of hydrogen to form an isomerization reactor-zone effluent; separating the isomerization reactor-zone effluent into an isomerization- zone product stream that comprises branched paraffins and a isomerization-zone net gas stream that comprises hydrogen, chloride-containing including HCI, and Cs- hydrocarbons; removing at least a portion of the chloride-containing compounds from the isomerization-zone net gas stream to form an HCl-scrubbed, isomerization-zone net gas stream;

removing water from the HCl-scrubbed, isomerization-zone net gas stream to form a water-depleted, HCl-scrubbed, isomerization-zone net gas stream; combining the water-depleted, HCl-scrubbed, isomerization-zone net gas stream with a reforming-zone net gas stream that comprises hydrogen and Ce- hydrocarbons in a re-contacting zone to form a combined net gas stream that comprises hydrogen and light end hydrocarbons; compressing the combined net gas stream with a compressor that is in the re-contacting zone to form a compressed combined net gas stream; introducing a reforming-zone product stream that comprises Cs+ hydrocarbons including aromatics to the re-contacting zone; and extracting the light end hydrocarbons from the compressed combined net gas stream in the re-contacting zone using the reforming-zone product stream to form a hydrogen-rich net gas stream and an aromatics-containing product stream.
17. The method according to claim 16, wherein the step of contacting includes contacting the paraffin feed stream that comprises Cs hydrocarbons, Cs hydrocarbons, or combinations thereof with the chloride-promoted isomerization catalyst.
18. The method according to claim 16, wherein the step of contacting includes contacting the paraffin feed stream that comprises C4 hydrocarbons with the chloride-promoted isomerization catalyst.
19. The method according to claim 16, further comprising the step of introducing the aromatics-containing product stream to a stabilizer to remove Cy- hydrocarbons and form a stabilized Cs+, -aromatics-containing product.
20. The method according to claim 16, further comprising the step of introducing the hydrogen-rich net gas stream to a chloride treater to remove chloride compounds.