1. A hybrid stripper-absorber column (100) for separating hydrogen sulfide (H₂S) and ammonia (NH₃) from sour water, the column comprising: a single column shell (102) having a top section (104) and a bottom stripping vapor zone/ section (106); a vertical bifurcation panel (110) disposed within the column shell (102), the vertical bifurcation panel (110) extending downward from the top section (104) and terminating above the bottom stripping vapor zone/ section (106), thereby dividing an upper portion of the column shell (102) into a hydrogen sulfide separation section (120), and an ammonia separation section (130), while maintaining a common bottom stripping vapor zone/ section (106) below the vertical bifurcation panel (110); a sour water feed inlet (108) configured to introduce sour water into the hydrogen sulfide separation section (120); a plurality of mass-transfer elements comprising trays or packing disposed within each of the hydrogen sulfide separation section (120) and the ammonia separation section (130); a reboiler (150) in fluid communication with the bottom stripping vapor zone/ section (106) and configured to generate stripping vapor; wherein the stripping vapor rises from the bottom stripping vapor zone/ section (106) and bifurcates at the vertical bifurcation panel (110) to flow upwardly through both the hydrogen sulfide separation section (120) and the ammonia separation section (130); and a liquid transfer channel (140) extending through or along the vertical bifurcation panel (110) for transferring liquid from the ammonia separation section (130) to the hydrogen sulfide separation section (120) by gravity-driven flow, thereby enabling simultaneous stripping and separation of hydrogen sulfide and ammonia from sour water within the single column shell (102).

2. The hybrid stripper-absorber column (100) as claimed in claim 1, wherein the vertical bifurcation panel (110) extends downward from the top section (104) toward the bottom stripping vapor zone/ section (106) to form hydraulically distinct separation zones within the column shell (102).

3. The hybrid stripper-absorber column (100) as claimed in claim 1, wherein the bottom stripping vapor zone/ section (106) is common to both the hydrogen sulfide separation section (120) and the ammonia separation section (130), thereby allowing stripping vapor generated by the reboiler (150) to be distributed to both sections.

4. The hybrid stripper-absorber column (100) as claimed in claim 1, further comprising a vertical exchanger (170) disposed within the hydrogen sulfide separation section (120), the vertical exchanger (170) being configured to: condense ammonia-water vapors, and reheat hydrogen sulfide-rich vapor above dew point.

5. The hybrid stripper-absorber column (100) as claimed in claim 1, wherein the ammonia separation section (130) comprises an absorption zone (180) configured to absorb residual hydrogen sulfide from ammonia-rich vapor using a liquid absorbent.

6. The hybrid stripper-absorber column (100) as claimed in claim 1, wherein the column (100) is configured to operate at a pressure in a range of 0.5–2 kg/cm²g using low-pressure steam supplied to the reboiler (150).

7. The hybrid stripper-absorber column (100) as claimed in claim 1, wherein the liquid transfer channel (140) comprises an inlet opening located in the ammonia separation section (130), a conduit extending through or along the vertical bifurcation panel (110), and an outlet opening located in the hydrogen sulfide separation section (120).

8. The hybrid stripper-absorber column (100) as claimed in claim 1, further comprising a caustic scrubber (200) configured to remove residual hydrogen sulfide from an ammonia-rich vapor stream exiting the ammonia separation section (130).

9. A sour water treatment system for separating hydrogen sulfide (H₂S) and ammonia (NH₃) from sour water, the system comprising: a hybrid stripper-absorber column (100) comprising: a single column shell (102) having a top section (104) and a bottom stripping vapor zone/ section (106); a vertical bifurcation panel (110) dividing an upper portion of the column shell (102) into a hydrogen sulfide separation section (120) and an ammonia separation section (130) while maintaining a common bottom stripping vapor zone/ section (106) below the vertical bifurcation panel (110); a sour water feed inlet (108) configured to introduce sour water into the hydrogen sulfide separation section (120); a plurality of mass-transfer elements disposed within the hydrogen sulfide separation section (120) and the ammonia separation section (130); a reboiler (150) connected to the bottom stripping vapor zone/ section (106) and configured to generate stripping vapor that rises and bifurcates at the vertical bifurcation panel (110); and a liquid transfer channel (140) configured to transfer liquid from the ammonia separation section (130) to the hydrogen sulfide separation section (120); a sour water feed line connected to the sour water feed inlet (108); a hydrogen sulfide product outlet (220) in fluid communication with the hydrogen sulfide separation section (120) for delivering hydrogen sulfide-rich vapor to a sulfur recovery unit; and an ammonia product outlet (230) in fluid communication with the ammonia separation section (130) for recovering ammonia-rich vapor.

10. A method for separating hydrogen sulfide (H₂S) and ammonia (NH₃) from sour water, the method comprising: providing a hybrid stripper-absorber column (100) comprising a single column shell (102) divided by a vertical bifurcation panel (110) into a hydrogen sulfide separation section (120) and an ammonia separation section (130) while maintaining a common bottom stripping vapor zone/ section (106) below the vertical bifurcation panel (110); introducing sour water into the hydrogen sulfide separation section (120); generating stripping vapor in the bottom stripping vapor zone/ section (106) using a reboiler (150) and allowing the stripping vapor to rise upwardly within the column shell (102); bifurcating the rising stripping vapor at the vertical bifurcation panel (110) and distributing the stripping vapor between the hydrogen sulfide separation section (120) and the ammonia separation section (130); contacting the sour water with the stripping vapor in the hydrogen sulfide separation section (120) to strip hydrogen sulfide; contacting liquid with the stripping vapor in the ammonia separation section (130) to strip ammonia; absorbing residual hydrogen sulfide from ammonia-rich vapor in an absorption zone (180) in the ammonia separation section (130); transferring liquid from the ammonia separation section (130) to the hydrogen sulfide separation section (120) through a liquid transfer channel (140); and withdrawing hydrogen sulfide-rich vapor, ammonia-rich vapor, and stripped water from the column (100).

Description:TECHNICAL FIELD
[0001] The present disclosure generally relates to the field of industrial separation equipment used in refinery and chemical processing operations. More particularly, the present disclosure relates to hybrid stripper-absorber column and method for separating hydrogen sulphide (H2S) and ammonia (NH3) from sour water streams generated during petroleum refining and related hydrocarbon processing operations. The hybrid stripper-absorber column enables selective separation of hydrogen sulfide and ammonia within a single column shell and facilitates improved mass transfer through internal liquid routing between the fractionation sections.

BACKGROUND
[0002] In petroleum refineries and other hydrocarbon processing facilities, sour water is generated as a by-product from several process units including crude distillation units, hydrocrackers, delayed cokers, fluid catalytic cracking units, and hydrodesulfurization units. Sour water typically contains dissolved hydrogen sulfide (H₂S) and ammonia (NH₃), along with smaller quantities of contaminants such as phenols, cyanides, and hydrocarbons. Before sour water can be reused or discharged to wastewater treatment systems, the dissolved hydrogen sulfide and ammonia must be removed to meet environmental and operational specifications. Conventionally, sour water treatment systems employ stripping columns that use steam to remove volatile components from the liquid phase.
[0003] Traditional sour water treatment systems commonly employ a two-stage stripping configuration. In such systems, a first column is used to preferentially remove hydrogen sulfide, while a second column is used to remove ammonia from the partially stripped water. Although such arrangements can achieve the desired separation, they require multiple vessels operating at different pressure levels, typically including a high-pressure hydrogen sulfide stripping column followed by a lower-pressure ammonia stripping column.
[0004] These conventional systems present several disadvantages. The use of multiple columns increases equipment footprint, capital cost, piping complexity, and operational maintenance requirements. Furthermore, the high-pressure operation often required for hydrogen sulfide removal leads to higher energy consumption due to the use of medium-pressure steam and elevated reboiler temperatures. The elevated temperatures and pressures also increase the risk of corrosion and fouling caused by ammonium salts and other contaminants.
[0005] In addition, conventional multi-column configurations may experience thermodynamic inefficiencies due to pressure differences and remixing of partially treated streams between columns. Such inefficiencies can increase steam consumption and reduce overall process efficiency. Accordingly, there exists a need for an improved sour water treatment apparatus and method that can effectively separate hydrogen sulfide and ammonia while reducing equipment complexity, energy consumption, and operational footprint.
[0006] Therefore, there is, a need to address at least the above-mentioned drawbacks and any other shortcomings, or at the very least, provide a valuable alternative to the existing methods and systems.

OBJECTS OF THE PRESENT DISCLOSURE
[0007] A general object of the present disclosure is to provide apparatus and method for separating hydrogen sulfide and ammonia from sour water that obviates the above-mentioned limitations of existing systems or methods effectively.
[0008] An object of the present disclosure is to provide an apparatus and method for separating hydrogen sulfide (H₂S) and ammonia (NH₃) from sour water within a single column shell.
[0009] Another object of the present disclosure is to provide an apparatus comprising a column shell having an internal vertical bifurcation panel that divides an upper portion of the column into separate fractionation sections while maintaining a common bottom stripping vapor zone/ section.
[0010] Another object of the present disclosure is to provide an apparatus in which a common bottom stripping vapor zone/ section supplied by a reboiler generates stripping vapor that rises into both fractionation sections within the column.
[0011] Another object of the present disclosure is to provide an apparatus including a liquid transfer channel arranged to transfer liquid from one fractionation section to another fractionation section to facilitate internal mass transfer and improve separation efficiency.
[0012] Another object of the present disclosure is to provide a system and method that reduce the number of required process vessels for sour water treatment compared with conventional multi-column configurations.
[0013] Another object of the present disclosure is to provide an apparatus that enables selective removal of hydrogen sulfide and ammonia within a single column while improving operational flexibility and process integration.
[0014] Another object of the present disclosure is to provide an apparatus and method that enhance process efficiency and reduce operational complexity in sour water treatment systems.
[0015] Another object of the present disclosure is to provide a compact sour water treatment apparatus suitable for integration into refinery and petrochemical processing facilities.

SUMMARY
[0016] Aspects of the present disclosure relate to the field of industrial separation equipment used in refinery and chemical processing operations. More particularly, the present disclosure relates to an apparatus and a method for separating hydrogen sulfide (H₂S) and ammonia (NH₃) from sour water streams generated during petroleum refining and related hydrocarbon processing operations. The apparatus enables selective separation of hydrogen sulfide and ammonia within a single column shell and facilitates improved mass transfer through internal liquid routing between the fractionation sections.
[0017] An aspect of the present disclosure relates to A hybrid stripper-absorber column for separating hydrogen sulfide (H₂S) and ammonia (NH₃) from sour water, the column includes a single column shell having a top section and a bottom stripping section. It further includes a vertical bifurcation panel disposed within the column shell, the vertical bifurcation panel extending downward from the top section and terminating above the bottom stripping section, thereby dividing an upper portion of the column shell into a hydrogen sulfide separation section, and an ammonia separation section, while maintaining a common bottom stripping vapor zone/ section below the vertical bifurcation panel. a sour water feed inlet configured to introduce sour water into the hydrogen sulfide separation section. A plurality of mass-transfer elements includes trays or packing disposed within each of the hydrogen sulfide separation section and the ammonia separation section. A reboiler in fluid communication with the bottom stripping section and configured to generate stripping vapour. The stripping vapor rises from the bottom stripping section and bifurcates at the vertical bifurcation panel to flow upwardly through both the hydrogen sulfide separation section and the ammonia separation section. A liquid transfer channel extending through or along the vertical bifurcation panel for transferring liquid from the ammonia separation section to the hydrogen sulfide separation section by gravity-driven flow, thereby enabling simultaneous stripping and separation of hydrogen sulfide and ammonia from sour water within the single column shell.
[0018] In an embodiment, the vertical bifurcation panel extends downward from the top section toward the bottom stripping vapor zone/ section to form hydraulically distinct separation zones within the column shell.
[0019] In an embodiment, the bottom stripping vapor zone/ section is common to both the hydrogen sulfide separation section and the ammonia separation section, thereby allowing stripping vapor generated by the reboiler to be distributed to both sections.
[0020] In an embodiment, the hybrid stripper-absorber column further may include a vertical exchanger disposed within the hydrogen sulfide separation section, the vertical exchanger being configured to: condense ammonia-water vapors, and reheat hydrogen sulfide-rich vapor above dew point.
[0021] In an embodiment, the ammonia separation section comprises an absorption zone configured to absorb residual hydrogen sulfide from ammonia-rich vapor using a liquid absorbent.
[0022] In an embodiment, the column is configured to operate at a pressure in a range of 0.5–2 kg/cm²g using low-pressure steam supplied to the reboiler.
[0023] In an embodiment, the liquid transfer channel comprises an inlet opening located in the ammonia separation section, a conduit extending through or along the vertical bifurcation panel (either externally or internally), and an outlet opening located in the hydrogen sulfide separation section.
[0024] In an embodiment, the hybrid stripper-absorber column may further include a caustic scrubber configured to remove residual hydrogen sulfide from an ammonia-rich vapor stream exiting the ammonia separation section.
[0025] Another aspect of the present disclosure relates to a sour water treatment system for separating hydrogen sulfide (H₂S) and ammonia (NH₃) from sour water, the system includes a hybrid stripper-absorber column includes: a single column shell having a top section and a bottom stripping section; a vertical bifurcation panel dividing an upper portion of the column shell into a hydrogen sulfide separation section and an ammonia separation section while maintaining a common bottom stripping vapor zone/ section below the vertical bifurcation panel; a sour water feed inlet configured to introduce sour water into the hydrogen sulfide separation section; a plurality of mass-transfer elements disposed within the hydrogen sulfide separation section and the ammonia separation section; a reboiler connected to the bottom stripping section and configured to generate stripping vapor that rises and bifurcates at the vertical bifurcation panel; and a liquid transfer channel configured to transfer liquid from the ammonia separation section to the hydrogen sulfide separation section; a sour water feed line connected to the sour water feed inlet; a hydrogen sulfide product outlet in fluid communication with the hydrogen sulfide separation section for delivering hydrogen sulfide-rich vapor to a sulfur recovery unit; and an ammonia product outlet in fluid communication with the ammonia separation section for recovering ammonia-rich vapor.
[0026] Yet another aspect of the present disclosure relates to a method for separating hydrogen sulfide (H₂S) and ammonia (NH₃) from sour water, the method includes providing a hybrid stripper-absorber column comprising a single column shell divided by a vertical bifurcation panel into a hydrogen sulfide separation section and an ammonia separation section while maintaining a common bottom stripping vapor zone/ section below the vertical bifurcation panel. The method may include introducing sour water into the hydrogen sulfide separation section and then generating stripping vapor in the bottom stripping section using a reboiler and allowing the stripping vapor to rise upwardly within the column shell. The method may further include bifurcating the rising stripping vapor at the vertical bifurcation panel and distributing the stripping vapor between the hydrogen sulfide separation section and the ammonia separation section and then contacting the sour water with the stripping vapor in the hydrogen sulfide separation section to strip hydrogen sulphide. Also the method may include contacting liquid with the stripping vapor in the ammonia separation section to strip ammonia. The method may then include absorbing residual hydrogen sulfide from ammonia-rich vapor in an absorption zone in the ammonia separation section and then transferring liquid from the ammonia separation section to the hydrogen sulfide separation section through a liquid transfer channel. Finally the method may finally include withdrawing hydrogen sulfide-rich vapor, ammonia-rich vapor, and stripped water from the column.

BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification.
[0028] FIG. 1 illustrates a schematic representation of a hybrid stripping column configuration depicting a column shell, divided by a vertical bifurcation panel into a first fractionation section and a second fractionation section while maintaining a common bottom stripping section connected to a reboiler, in accordance to an embodiment of the present disclosure.
[0029] FIG. 2 illustrates a schematic diagram of an alternative configuration of the hybrid column in which the first fractionation section and the second fractionation section, while maintaining a common bottom stripping vapor zone connected to a reboiler, are arranged within the column shell with associated vapor-liquid contacting devices and an integrated heat exchanger positioned within the column, in accordance to an embodiment of the present disclosure.
[0030] FIG. 3A illustrates a schematic diagram of an embodiment depicting a caustic scrubber integrated with the column shell to remove hydrogen sulfide from an ammonia-containing vapor stream exiting the column, in accordance to an embodiment of the present disclosure.
[0031] FIG. 3B illustrates a schematic diagram of an alternative embodiment depicting the caustic scrubber as a separate vessel positioned externally to the column shell and connected to receive the ammonia-containing vapor stream, in accordance to an embodiment of the present disclosure.

DETAILED DESCRIPTION
[0032] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the scope of the present disclosures as defined by the appended claims.
[0033] Embodiments of the present disclosure relate to the field of industrial separation equipment used in refinery and chemical processing operations. More particularly, the present disclosure relates to an apparatus and a method for separating hydrogen sulfide (H₂S) and ammonia (NH₃) from sour water streams generated during petroleum refining and related hydrocarbon processing operations. The apparatus enables selective separation of hydrogen sulfide and ammonia within a single column shell and facilitates improved mass transfer through internal liquid routing between the fractionation sections.
[0034] FIG. 1 illustrates a schematic representation of a hybrid stripping column configuration depicting a column shell, divided by a vertical bifurcation panel into a first fractionation section and a second fractionation section while maintaining a common bottom stripping section connected to a reboiler, in accordance to an embodiment of the present disclosure. In the hydrogen sulfide fractionation side, the cooling & heating exchangers are externally integrated with the top section vapor.
[0035] Referring initially to Fig. 1, a hybrid stripper-absorber column 100 is provided for separating hydrogen sulfide (H₂S) and ammonia (NH₃) from sour water generated in refinery, petrochemical, and gas processing facilities. Sour water streams commonly contain dissolved hydrogen sulfide, ammonia, and trace contaminants including phenols, cyanides, and hydrocarbons, which must be removed prior to reuse or discharge to environmental treatment systems.
[0036] The hybrid stripper-absorber column 100 integrates multiple separation and purification functions within a single column shell to enable efficient separation of hydrogen sulfide and ammonia while reducing energy consumption, equipment footprint, and capital cost relative to conventional multi-column sour water stripping systems. The hybrid column 100 comprises a column shell 102 defining an internal column volume. The column shell includes a top section (upper column section) 104 and a bottom stripping vapor zone/ section 106 located at a lower portion of the column.
[0037] A vertical bifurcation panel 110 is disposed within the column shell 102. The vertical bifurcation panel extends downward from the top section 104 and terminates above the bottom stripping vapor zone/ section 106, thereby dividing the upper portion of the column shell into two internal processing regions while maintaining a common bottom stripping vapor zone/ section.
[0038] Specifically, the vertical bifurcation panel 110 defines: a hydrogen sulfide separation section 120, and an ammonia separation section 130. The bottom stripping section 106 remains common to both separation sections so that vapor generated in the bottom stripping section can rise into both internal sections of the column. The column shell 102 forms the outer pressure-containing vessel of the hybrid stripper-absorber column 100. The shell is typically a vertically oriented cylindrical vessel designed to withstand the temperatures, pressures, and corrosive conditions associated with sour water processing.
[0039] In certain embodiments the column operates at pressures in the range of 0.5 to 2 kg/cm²g and temperatures up to approximately 130°C. The diameter of the column shell 102 may vary depending on throughput requirements. Typical column diameters may range from approximately 1.5 meters to 6 meters, although larger or smaller diameters may be used depending on plant capacity. The column shell 102 may be constructed from corrosion-resistant materials suitable for hydrogen sulfide and ammonia service. Suitable materials include carbon steel with corrosion allowance, stainless steel alloys such as 316L or 317L, duplex stainless steels such as 2205, or other corrosion-resistant materials.
[0040] In certain embodiments the interior surfaces of the column shell 102 may include corrosion-resistant linings or cladding materials to further improve durability in aggressive process environments. The vertical bifurcation panel 110 is a vertically oriented internal partition that divides the upper portion of the column shell 102 into the hydrogen sulfide separation section 120 and the ammonia separation section 130.
[0041] The panel extends downward from the top section 104 but terminates above the bottom stripping vapor zone/ section 106, thereby allowing both sections to share the common bottom stripping vapor zone/ section. The vertical bifurcation panel 110 provides physical separation between the two internal regions of the column and prevents undesired cross-mixing of vapor and liquid streams associated with the different separation functions.
[0042] In certain embodiments the panel may be fabricated from corrosion-resistant materials such as stainless steel, duplex stainless steel, or nickel-based alloys suitable for hydrogen sulfide service. The panel thickness may typically range from approximately 6 mm to 20 mm, depending on column diameter and structural requirements. In some implementations the panel may be welded or otherwise sealed to the column shell along its vertical edges to minimize vapor or liquid bypass between the two sections. The geometry of the bifurcation panel may be designed such that the hydrogen sulfide separation section 120 and ammonia separation section 130 have different cross-sectional flow areas. In certain configurations the cross-sectional area of the hydrogen sulfide separation section may be greater than that of the ammonia separation section, for example within an area ratio of approximately 1.2:1 to 2:1. This arrangement can direct a larger proportion of stripping vapor toward the hydrogen sulfide section to improve stripping performance.
[0043] Sour water is introduced into the column through a sour water feed inlet 108, which is connected to a sour water feed line. As illustrated in Fig. 1, the sour water feed inlet 108 is positioned such that sour water enters the hydrogen sulfide separation section 120. Prior to entering the hybrid stripper-absorber column 100, the sour water stream may optionally pass through upstream equipment such as flash drums or separators that remove hydrocarbons and non-condensable gases.
[0044] Once inside the column, the sour water flows downward through the hydrogen sulfide separation section under gravitational forces while interacting with rising vapor streams. During operation, sour water introduced into the hydrogen sulfide separation section 120 contacts rising stripping vapor to separate hydrogen sulfide, while liquid present in the ammonia separation section 130 contacts stripping vapor to separate ammonia.
[0045] The bottom stripping vapor zone/ section 106 functions as the primary vapor generation zone of the column. A reboiler 150 is connected to the bottom stripping section and supplies heat to the liquid contained within this region. The reboiler may be configured as a kettle reboiler, thermosiphon reboiler, or forced-circulation reboiler depending on the process design. In certain embodiments the reboiler is heated using low-pressure steam, which may be readily available in refinery facilities. The reboiler typically operates at temperatures in the range of approximately 125–130°C.
[0046] Heat supplied by the reboiler 150 vaporizes a portion of the liquid in the bottom stripping vapor zone/ section 106, thereby generating a stripping vapor stream. Because the bottom stripping vapor zone/ section 106 is common to both internal regions of the column, the generated vapor rises upward toward the vertical bifurcation panel 110.
[0047] As the stripping vapor rises within the column shell 102, it encounters the vertical bifurcation panel 110. The vertical bifurcation panel causes the vapor stream to divide and flow upwardly through both: the hydrogen sulfide separation section 120, and the ammonia separation section 130. This bifurcation of the vapor stream enables simultaneous stripping of hydrogen sulfide and ammonia in two separate sections of the same column shell.
[0048] The distribution of vapor between the two sections may be influenced by the cross-sectional areas defined by the bifurcation panel and by internal hydraulic conditions within the column. Both separation sections contain a plurality of vapor-liquid contacting devices 160 arranged vertically along the column. The contacting devices promote mass transfer between rising vapor and descending liquid streams.
[0049] In certain embodiments the contacting devices 160 may include trays such as valve trays, sieve trays, or bubble-cap trays. Alternatively, the column sections may incorporate structured packing or random packing materials that provide large surface area for vapor-liquid contact. The number of trays used in each section may vary depending on separation requirements. In some configurations the hydrogen sulfide stripping section may contain approximately 10 to 30 trays, while the ammonia stripping section may contain approximately 5 to 25 trays. Tray spacing may typically range between 450 mm and 600 mm.
[0050] As vapor rises through the contacting devices 160, it strips volatile components from the descending liquid streams, thereby promoting separation of hydrogen sulfide and ammonia from the sour water. A liquid transfer channel 140 is provided to transfer liquid between the ammonia separation section 130 and the hydrogen sulfide separation section 120.
[0051] The liquid transfer channel 140 includes: an inlet opening positioned in the ammonia separation section 130, a conduit extending through or along the vertical bifurcation panel 110, and an outlet opening located in the hydrogen sulfide separation section 120. Liquid accumulated in the ammonia separation section 130 can flow through the inlet opening 142, pass through the conduit 144, and exit through the outlet opening 146 into the hydrogen sulfide separation section.
[0052] The transfer channel is oriented such that liquid flows through the channel primarily by gravity. Because the outlet opening is typically positioned at a lower hydraulic elevation than the inlet opening, gravity-driven flow enables transfer of liquid without the need for external pumping equipment.
[0053] This internal liquid transfer improves separation efficiency by allowing hydrogen sulfide absorbed in the ammonia section to be redirected into the hydrogen sulfide section for stripping.
[0054] In certain embodiments the hydrogen sulfide separation section 120 includes a vertical exchanger 170 positioned above the stripping trays. The vertical exchanger 170 may perform two functions. First, the exchanger may condense ammonia and water vapor from the rising vapor stream. The resulting condensate drains back into the column, thereby improving separation efficiency. Second, the exchanger may reheat hydrogen sulfide-rich vapor prior to withdrawal from the column so that the gas temperature remains above its dew point. Maintaining the hydrogen sulfide vapor above its dew point helps reduce corrosion risks in downstream piping and equipment.
[0055] The ammonia separation section 130 may include an absorption zone 180 located in an upper portion of the column. The absorption zone allows residual hydrogen sulfide present in the ammonia-rich vapor stream to be removed through gas-liquid absorption. Within the absorption zone 180, a liquid absorbent such as ammonia-rich water or stripped water may be introduced and allowed to flow downward across trays or packing while vapor rises upward. During this contact, hydrogen sulfide present in the vapor phase dissolves into the liquid phase, thereby producing a purified ammonia-rich vapor stream. The resulting hydrogen sulfide-rich liquid may then flow through the liquid transfer channel 140 into the hydrogen sulfide separation section for stripping.
[0056] FIG. 2 illustrates a schematic diagram of an alternative configuration of the hybrid column in which the first fractionation section and the second fractionation section, while maintaining a common bottom stripping vapor zone connected to a reboiler, are arranged within the column shell with associated vapor-liquid contacting devices and an integrated heat exchanger positioned within the column, in accordance to an embodiment of the present disclosure.
[0057] Referring to FIG. 2, an alternative configuration of the hybrid stripper-absorber column 100 is illustrated. In this configuration certain internal elements such as the vertical exchanger 170, liquid transfer channel 140, or absorption zone 180 may be arranged differently within the column. Despite these variations, the fundamental architecture of the hybrid column remains the same. The column shell 102 still contains the vertical bifurcation panel 110 that divides the upper column section into two internal regions while maintaining the common bottom stripping vapor zone 106 supplied by the reboiler 150. Both the schemes may have top caustic scrubbing sections (200) above the absorption section 180.
[0058] FIG. 3A illustrates a schematic diagram of an embodiment depicting a caustic scrubber is integrated with the column shell to remove hydrogen sulfide from an ammonia-containing vapor stream exiting the column, in accordance to an embodiment of the present disclosure.
[0059] Referring to FIG. 3A, a caustic scrubber 200 may be mounted atop the hybrid stripper-absorber column 100. The caustic scrubber includes a scrubber section 202 containing a caustic solution 204, typically an aqueous sodium hydroxide solution. The scrubber vessel 202 may include one or more circular gas distributor pipes 206 having perforations 208 for dispersing gas into the caustic solution. The scrubber may further include riser pipes 210 and U-loops 212 that guide vapor through the caustic solution while preventing undesired backflow of liquid into ammonia side absorption section 180.
[0060] A slanted base 214 may be provided at the bottom of the scrubber section to facilitate drainage of accumulated solids and improve operational reliability. When ammonia-rich vapor exits the ammonia separation section 130, it can be routed through the caustic scrubber 200 where residual hydrogen sulfide reacts with the caustic solution and is removed from the gas stream.
[0061] FIG. 3B illustrates a schematic diagram of an alternative embodiment depicting the caustic scrubber is provided as a separate vessel positioned externally to the column shell and connected to receive the ammonia-containing vapor stream, in accordance to an embodiment of the present disclosure.
[0062] Referring to FIG. 3B, the caustic scrubber 200 may alternatively be installed as a standalone vessel separate from the hybrid column 100. In this arrangement ammonia-rich vapor streams are routed through external piping to the scrubber vessel 202, where they contact the caustic solution 204. The internal structure of the standalone scrubber remains substantially similar to the integrated configuration described above. The hybrid stripper-absorber column 100 may be equipped with instrumentation and control systems that monitor and regulate key process variables including temperature, pressure, liquid level, and flow rates. Instrumentation may be located at the sour water feed inlet 108, reboiler 150, separation section outlets, and product withdrawal points. These control systems ensure stable column operation, maintain hydraulic balance between the two internal sections, and ensure that product specifications are consistently achieved. In the standalone configuration shown in FIG. 3B, the scrubber vessel 202 may be provided with main circular gas distributor header 215 for uniform gas distribution and the vessel may be mounted on structural support that positions the scrubber above ground level and provides access for maintenance and piping connections.
[0063] Under these operating conditions hydrogen sulfide vapor may be withdrawn from the column through the hydrogen sulfide outlet 220, while ammonia-rich vapor may be withdrawn through the ammonia outlet 230. Stripped water exiting through the stripped water outlet may contain hydrogen sulfide and ammonia concentrations below 10 ppmw, suitable for reuse or discharge to downstream treatment facilities.
[0064] Therefore the present disclosure provides the hybrid stripper-absorber column (100) for separating hydrogen sulfide (H₂S) and ammonia (NH₃) from sour water generated during petroleum refining and related hydrocarbon processing operations. The hybrid stripper-absorber column enables selective separation of hydrogen sulfide and ammonia within a single column shell and facilitates improved mass transfer through internal liquid routing between the fractionation sections.
[0065] While the foregoing describes various embodiments of the disclosure, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the disclosure is determined by the claims that follow. The disclosure is not limited to the described embodiments, versions, or examples, which are included to enable a person having ordinary skill in the art to make and use the disclosure when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF THE PRESENT DISCLOSURE
[0066] The present disclosure discloses provides a hybrid stripper-absorber column configured to selectively separate hydrogen sulfide and ammonia from sour water streams within a single column shell, thereby enabling simultaneous fractionation and purification of process streams while maintaining a common bottom stripping vapor zone/ section supplied by a single reboiler.
[0067] The present disclosure discloses a hybrid stripper-absorber column and method which reduces energy consumption and equipment footprint by integrating hydrogen sulfide stripping, ammonia stripping, and optional absorption/ scrubbing operations within a single vessel, thereby eliminating the need for multiple conventional stripping columns and associated auxiliary equipment.
[0068] The present disclosure discloses a hybrid stripper-absorber column and method which offers improved process efficiency and operational reliability through the use of a vertical bifurcation panel and a gravity-driven liquid transfer channel that facilitates controlled distribution of vapor and liquid streams between separation sections, thereby improving separation performance while minimizing mechanical complexity. , Claims:1. A hybrid stripper-absorber column (100) for separating hydrogen sulfide (H₂S) and ammonia (NH₃) from sour water, the column comprising:
a single column shell (102) having a top section (104) and a bottom stripping vapor zone/ section (106);
a vertical bifurcation panel (110) disposed within the column shell (102), the vertical bifurcation panel (110) extending downward from the top section (104) and terminating above the bottom stripping vapor zone/ section (106), thereby dividing an upper portion of the column shell (102) into a hydrogen sulfide separation section (120), and an ammonia separation section (130), while maintaining a common bottom stripping vapor zone/ section (106) below the vertical bifurcation panel (110);
a sour water feed inlet (108) configured to introduce sour water into the hydrogen sulfide separation section (120);
a plurality of mass-transfer elements comprising trays or packing disposed within each of the hydrogen sulfide separation section (120) and the ammonia separation section (130);
a reboiler (150) in fluid communication with the bottom stripping vapor zone/ section (106) and configured to generate stripping vapor;
wherein the stripping vapor rises from the bottom stripping vapor zone/ section (106) and bifurcates at the vertical bifurcation panel (110) to flow upwardly through both the hydrogen sulfide separation section (120) and the ammonia separation section (130); and
a liquid transfer channel (140) extending through or along the vertical bifurcation panel (110) for transferring liquid from the ammonia separation section (130) to the hydrogen sulfide separation section (120) by gravity-driven flow, thereby enabling simultaneous stripping and separation of hydrogen sulfide and ammonia from sour water within the single column shell (102).
2. The hybrid stripper-absorber column (100) as claimed in claim 1, wherein the vertical bifurcation panel (110) extends downward from the top section (104) toward the bottom stripping vapor zone/ section (106) to form hydraulically distinct separation zones within the column shell (102).
3. The hybrid stripper-absorber column (100) as claimed in claim 1, wherein the bottom stripping vapor zone/ section (106) is common to both the hydrogen sulfide separation section (120) and the ammonia separation section (130), thereby allowing stripping vapor generated by the reboiler (150) to be distributed to both sections.
4. The hybrid stripper-absorber column (100) as claimed in claim 1, further comprising a vertical exchanger (170) disposed within the hydrogen sulfide separation section (120), the vertical exchanger (170) being configured to: condense ammonia-water vapors, and reheat hydrogen sulfide-rich vapor above dew point.
5. The hybrid stripper-absorber column (100) as claimed in claim 1, wherein the ammonia separation section (130) comprises an absorption zone (180) configured to absorb residual hydrogen sulfide from ammonia-rich vapor using a liquid absorbent.
6. The hybrid stripper-absorber column (100) as claimed in claim 1, wherein the column (100) is configured to operate at a pressure in a range of 0.5–2 kg/cm²g using low-pressure steam supplied to the reboiler (150).
7. The hybrid stripper-absorber column (100) as claimed in claim 1, wherein the liquid transfer channel (140) comprises an inlet opening located in the ammonia separation section (130), a conduit extending through or along the vertical bifurcation panel (110), and an outlet opening located in the hydrogen sulfide separation section (120).
8. The hybrid stripper-absorber column (100) as claimed in claim 1, further comprising a caustic scrubber (200) configured to remove residual hydrogen sulfide from an ammonia-rich vapor stream exiting the ammonia separation section (130).
9. A sour water treatment system for separating hydrogen sulfide (H₂S) and ammonia (NH₃) from sour water, the system comprising:
a hybrid stripper-absorber column (100) comprising:
a single column shell (102) having a top section (104) and a bottom stripping vapor zone/ section (106);
a vertical bifurcation panel (110) dividing an upper portion of the column shell (102) into a hydrogen sulfide separation section (120) and an ammonia separation section (130) while maintaining a common bottom stripping vapor zone/ section (106) below the vertical bifurcation panel (110);
a sour water feed inlet (108) configured to introduce sour water into the hydrogen sulfide separation section (120);
a plurality of mass-transfer elements disposed within the hydrogen sulfide separation section (120) and the ammonia separation section (130);
a reboiler (150) connected to the bottom stripping vapor zone/ section (106) and configured to generate stripping vapor that rises and bifurcates at the vertical bifurcation panel (110); and
a liquid transfer channel (140) configured to transfer liquid from the ammonia separation section (130) to the hydrogen sulfide separation section (120);
a sour water feed line connected to the sour water feed inlet (108);
a hydrogen sulfide product outlet (220) in fluid communication with the hydrogen sulfide separation section (120) for delivering hydrogen sulfide-rich vapor to a sulfur recovery unit; and
an ammonia product outlet (230) in fluid communication with the ammonia separation section (130) for recovering ammonia-rich vapor.
10. A method for separating hydrogen sulfide (H₂S) and ammonia (NH₃) from sour water, the method comprising:
providing a hybrid stripper-absorber column (100) comprising a single column shell (102) divided by a vertical bifurcation panel (110) into a hydrogen sulfide separation section (120) and an ammonia separation section (130) while maintaining a common bottom stripping vapor zone/ section (106) below the vertical bifurcation panel (110);
introducing sour water into the hydrogen sulfide separation section (120);
generating stripping vapor in the bottom stripping vapor zone/ section (106) using a reboiler (150) and allowing the stripping vapor to rise upwardly within the column shell (102);
bifurcating the rising stripping vapor at the vertical bifurcation panel (110) and distributing the stripping vapor between the hydrogen sulfide separation section (120) and the ammonia separation section (130);
contacting the sour water with the stripping vapor in the hydrogen sulfide separation section (120) to strip hydrogen sulfide;
contacting liquid with the stripping vapor in the ammonia separation section (130) to strip ammonia;
absorbing residual hydrogen sulfide from ammonia-rich vapor in an absorption zone (180) in the ammonia separation section (130);
transferring liquid from the ammonia separation section (130) to the hydrogen sulfide separation section (120) through a liquid transfer channel (140); and
withdrawing hydrogen sulfide-rich vapor, ammonia-rich vapor, and stripped water from the column (100).