Method for production of blue ammonia

Abstract

The present invention relates to an ammonia plant and process for production of ammonia. A syngas purification section comprises a PSA unit and a cryogenic CO2 removal unit. Heat from the shift section is used to generate electrical power in an alternator.

Description

[0001] METHOD FOR PRODUCTION OF BLUE AMMONIA

[0002] TECHNICAL FIELD

[0003] The present invention relates to an ammonia plant and process for production of ammonia. A syngas purification section comprises a PSA unit and a cryogenic CO2 removal unit. Heat from the shift section is used to generate electrical power in an alternator.

[0004] BACKGROUND

[0005] Blue ammonia is a fossil fuel-based product produced with minimum emission of CO2 to the atmosphere. It is seen as a transition product between conventional fossil fuel-based ammonia and green ammonia produced from green or renewable power, water and air. The CO2 resulting from a blue ammonia production shall be stored permanently or converted into other chemicals. The main steps for producing blue ammonia are essentially the same as for producing conventional fossil fuel-based ammonia, the difference being that more of the carbon stemming from the carbon fuel is captured, providing a possibility for further processing.

[0006] The key here is that the blue ammonia does not release any carbon dioxide when used as fertilizer or burned . Currently available technology traps nearly all CO2 generated during the conversion process making this fuel one of the first carbon free fuel options for mass use. Blue ammonia is considered an environmentally friendly product which can be used until sufficient renewable or green power is available for producing green ammonia.

[0007] Utility prices vary dependent on plant / site location. The blue ammonia layout that becomes the most optimal and attractive varies for given specific utility prices. It may also be desirable to avoid, or reduce the need for, a fired steam superheater.

[0008] In standard amine-based CO2 capture, a stripper reboiler is required to regenerate active amine. Heat generated in the shift process is normally used to power this stripper reboiler. However, when cryogenic CO2 removal is used the duty normally used for reboiler duty in amine regeneration cannot be used and contributes to added cooling cost.

[0009] It is desirable to provide an ammonia plant, in which duty generated in the shift section can be used elsewhere. Known technology within this field is described in WO2018 / 149641, PCT / EP2022 / 059091 and PCT / EP2023 / 061637.

[0010] SUMMARY

[0011] An ammonia plant is provided, said plant comprising : a hydrocarbon feed; a burner steam feed; a first process steam feed; a second process steam feed; an oxygen feed; a nitrogen feed; a high pressure boiler feed water; a low pressure boiler feed water; a feed pre-heater being arranged to pre-heat the hydrocarbon feed and to generate a pre-heated hydrocarbon feed a feed purification section, being arranged to hydrogenate and remove sulfur compounds from the preheated hydrocarbon feed, and to generate a purified hydrocarbon feed; a prereformer feed preheater arranged to heat a combined stream comprising purified hydrocarbon feed and process steam feed and to generate a heated combined stream; a prereforming section arranged to pre-reform the heated combined stream from the prereformer feed preheater and to generate a first process gas stream; a process gas pre-heater arranged to heat said first process gas stream and to generate a heated first process gas stream; an autothermal reforming ATR section arranged to receive at least a portion of the heated first process gas stream, said oxygen feed and said burner steam feed and to generate a second process gas stream; a steam drum arranged to receive at least a portion of the high pressure boiler feed water and supply (at least one) first boiler water stream; a first waste heat boiler arranged to heat exchange at least a portion of the second process gas stream with the first boiler water stream from said steam drum and generate a cooled second process gas stream and a first steam stream; a high temperature (HT) shift section arranged to receive the cooled second process gas stream from the first waste heat boiler and the second process steam feed, and to generate a third process gas stream; a second shift section arranged to receive the cooled third process gas stream and generate a fourth process gas stream; a low pressure waste heat boiler arranged to receive the low pressure boiler feed water, and heat exchange at least a portion of the low pressure boiler feed water with the fourth process gas stream from said second shift section; and to generate a low pressure steam stream and a cooled fourth process gas stream; a low pressure steam superheater arranged to heat exchange at least a first portion of the low pressure steam stream from the low pressure waste heat boiler with the third process gas stream from the high temperature (HT) shift section, so as to generate a low pressure superheated steam stream and a cooled third process gas stream; an alternator, said alternator being arranged to receive at least a portion of the low pressure superheated steam stream, and to generate electrical power; a syngas purification section comprising, in order: a separator section, a pressure swing absorption (PSA) unit and a cryogenic CO2 removal unit; wherein the separator section is arranged to receive said cooled fourth process gas stream and generate a dried fourth process gas stream and a process condensate, wherein the PSA unit is arranged to receive the dried fourth process gas stream and to generate a hydrogen product stream and a tail gas stream, and wherein the CO2 removal unit is arranged to receive said tail gas stream from the PSA unit and to generate a CC -rich stream, a carbon-containing ATR. recycle stream and an offgas fuel stream, and an ammonia synthesis loop arranged to receive at least a first portion of the hydrogen product stream from the PSA unit, said nitrogen feed, and a portion of the boiler feed water, and to generate a first ammonia-rich stream and a second steam stream.

[0012] A process for generating ammonia in the ammonia plant described herein is also provided.

[0013] This technology provides a new optimized layout. The new optimized layout is a layout utilizing low temperature calories downstream the low temperature (LT) shift converter and downstream a high pressure (HP) boiler feed water (BFW) preheater for low pressure (LP) steam generation and demineralized water (DMW) preheating. The generated LP steam is superheated in the process in a steam superheater heat exchanger and is subsequently used as injection steam in a turbine alternator for additional power generation.

[0014] Further details of the plant and process are specified in the following detailed description, figures and claims. LEGENDS

[0015] Fig. 1 shows a layout of an ammonia plant according to the invention.

[0016] DETAILED DISCLOSURE

[0017] Unless otherwise specified, any given percentages for gas content are % by volume. The terms "synthesis gas" and "syngas" are used interchangeably in this text.

[0018] An ammonia plant (A) is provided. The feeds inputted to the plant comprise: a hydrocarbon feed (typically natural gas or biogas) a burner steam feed; a first process steam feed; a second process steam feed; an oxygen feed; a nitrogen feed; a high pressure boiler feed water; and a low pressure boiler feed water.

[0019] A feed pre-heater is arranged to pre-heat the hydrocarbon feed and to generate a pre-heated hydrocarbon feed. Typical temperatures of the preheated hydrocarbon feed are between 350 and 400°C. Preheating of the hydrocarbon feed may take place in a heater coil within a fired heater. Alternatively, the feed pre-heater may be an electrical heater or a steam preheater.

[0020] A feed purification section is arranged to hydrogenate and remove sulfur compounds from the preheated hydrocarbon feed, and to generate a purified hydrocarbon feed. The feed purification section suitably comprises a hydrogenation unit upstream a sulfur removal unit. Hydrogenation removes any unsaturated components of the hydrocarbon feed. Both unsaturated components of the hydrocarbon feed and sulfur components may contaminate downstream catalysts in the ammonia plant.

[0021] The purified hydrocarbon feed is combined with process steam feed and then heated again in a prereformer feed preheater to generate a heated combined stream. Typical temperatures of the heated combined stream are between 400 and 550°C. The prereformer feed preheater may comprise a heater coil within a fired heater. Alternatively, the prereformer feed preheater may be an electrical heater. The heated combined stream is fed to prereforming section, which is arranged to pre-reform the heated combined stream and to generate a first process gas stream. Pre-reforming is the process by which methane and heavier hydrocarbons are steam reformed and the products of the heavier hydrocarbon reforming are methanated. Typically, a nickel-containing catalyst is used. Pre-reforming sections suitable for this process are known to the person skilled in the art.

[0022] First process gas stream is then fed to a process gas pre-heater which is arranged to heat this first process gas stream and to generate a heated first process gas stream. Typical temperatures of the heated first process gas stream are between 350 and 650 °C.

[0023] The plant comprises an autothermal reforming ATR section arranged to receive at least a portion of the heated first process gas stream, optionally an offgas recycle stream from downstream recycled back to the ATR, the oxygen feed and the burner steam feed and to generate a second process gas stream. Autothermal reforming sections, catalysts and conditions are known to the person skilled in the art.

[0024] The ammonia plant comprises a steam drum. The steam drum is arranged to receive high pressure boiler feed water and supply a first boiler water stream.

[0025] A first waste heat boiler is arranged to heat exchange at least a portion of the second process gas stream with the first boiler water stream from the steam drum and generate a cooled second process gas stream and a first steam stream.

[0026] A high temperature (HT) shift section is arranged to receive the cooled second process gas stream from the first waste heat boiler, as well as the second process steam feed, and generate a third process gas stream. By means of the shift sections, the desired composition of the syngas can be achieved. Shift means Water-gas shift reaction (WGSR) or Shift reaction, the reaction of carbon monoxide and water vapor to form carbon dioxide and hydrogen:

[0027] CO + H2O CO2 + H2

[0028] The WGSR is an important industrial reaction that is used in the manufacture of ammonia, hydrocarbons, methanol, and hydrogen. It is also often used in conjunction with steam reforming of methane and other hydrocarbons. In the Fischer-Tropsch process, the WGSR is one of the most important reactions used to balance the H2 / CO ratio. The water gas shift reaction is a moderately exothermic reversible reaction. Therefore, with increasing temperature the reaction rate increases but the carbon dioxide production becomes less favourable. Due to its exothermic nature, high carbon monoxide percentage is thermodynamically favoured at low temperatures. Despite the thermodynamic favourability at low temperatures, the reaction is faster at high temperatures.

[0029] Subsequently, a second shift section is arranged to receive the third process gas stream and generate a fourth process gas stream. The second shift section may be a low temperature (LT) or a medium temperature (MT) shift section, and is preferably a low temperature shift section. LT shift typically takes place at temperatures between process gas Tdew+ 15°C and 250°C, while MT shift typically takes place between 190 - 330°C. At this point, CO is shifted to a minimum to maximize H2 production and to increase process carbon capture.

[0030] A low pressure waste heat boiler is arranged to receive the low pressure boiler feed water, and heat exchange at least a portion of the low pressure boiler feed water with the fourth process gas stream from said second shift section; and to generate a low pressure steam stream and a cooled fourth process gas stream.

[0031] A low pressure steam superheater is arranged to heat exchange at least a first portion of the low pressure steam stream from the low pressure waste heat boiler with the third process gas stream from the high temperature (HT) shift section, so as to generate a low pressure superheated steam stream and a cooled third process gas stream.

[0032] A syngas purification section comprises, in order: a separator section, a pressure swing absorption unit and a cryogenic CO2 removal unit.

[0033] The separator section is arranged to receive said cooled fourth process gas stream and generate a dried fourth process gas stream and a process condensate stream.

[0034] The PSA unit is arranged to receive the dried fourth process gas stream and to generate a hydrogen product stream and a tail gas stream.

[0035] The cryogenic CO2 removal unit is arranged to receive said tail gas stream from the PSA unit and to generate a CCh-rich stream, a carbon-containing ATR. recycle stream and an offgas fuel stream and optionally an additional hydrogen product stream.

[0036] The syngas purification section is arranged to mix at least a first portion of the hydrogen product stream from the PSA unit with the nitrogen feed and generate a syngas stream. The ammonia synthesis loop is arranged to receive at least a first portion of the hydrogen product stream from the PSA unit, and said nitrogen feed (preferably in admixture, in the form of a syngas stream), and a portion of the boiler feed water, and to generate a first ammonia- rich stream and a second steam stream.

[0037] In one layout of the ammonia plant, the ammonia synthesis loop comprises an ammonia reactor, a compressor section (both a makeup and a recycle syngas compressor), an ammonia separator, at least one waste heat boiler, and optionally a steam superheater. The waste heat boiler and optional steam superheater are arranged downstream the ammonia reactor, wherein said portion of the boiler feed water is arranged to be heat exchanged in said at least one waste heat boiler with the effluent from the ammonia reactor, and optionally said steam superheater, so as to generate said second steam stream.

[0038] In one aspect, the ammonia plant does not comprise a fired steam superheater. In another aspect, the ammonia plant comprises a fired heater and a fuel stream for said fired heater. At least one - and preferably all - of said feed pre-heater, prereformer feed preheater and syngas pre-heater comprise a heater coil within said fired heater.

[0039] Various streams in the plant can be used as (part of) the fuel for the fired heater. Advantageously, offgas from the purification unit and hydrogen rich fuel stream(s) and optionally, a portion of the syngas stream comprising hydrogen and nitrogen are arranged to be fed as fuel(s) to the fired heater. In another variation, a second portion of the hydrogen product stream from the PSA unit is arranged to be fed as fuel to the fired heater. Furthermore, at least a portion of the offgas fuel stream from the cryogenic CO2 removal unit, may be arranged to be fed as fuel to the fired heater, optionally in combination with a portion of the syngas stream.

[0040] The ammonia synthesis loop suitably comprises an ammonia reactor, a compressor section, an ammonia separator, at least one waste heat boiler and optionally a steam superheater, said at least one waste heat boiler and optional steam superheater being arranged downstream the ammonia reactor, wherein said portion of the boiler feed water is arranged to be heat exchanged in said at least one waste heat boiler with the effluent from the ammonia reactor, and optionally said steam superheater, so as to generate said second steam stream.

[0041] In one aspect, a high pressure steam stream is also arranged to be provided to the alternator. The autothermal reforming ATR section may also be arranged to receive at least a portion of the carbon-containing ATR recycle stream at the inlet of said ATR section, suitably in admixture with the heated first process gas stream.

[0042] The ammonia plant may further comprise a demineralised water (DMW) preheater and a process gas cooler arranged to further cool the cooled fourth process gas stream upstream the separator section.

[0043] In one aspect, the cryogenic CO2 removal unit comprises a cryogenic CO2 fractionation system, followed by at least one overhead (OHVD) PSA unit, and optionally a membrane separation unit arranged downstream the overhead (OHVD) PSA unit.

[0044] A process is also provided for generating ammonia in the ammonia plant (A) described herein, said process comprising the steps of: providing the plant as defined herein, pre-heating the hydrocarbon feed in the feed pre-heater and generating a pre-heated hydrocarbon feed; hydrogenating and removing sulfur compounds from the preheated hydrocarbon feed in the feed purification section, and generating a purified hydrocarbon feed; heating a combined stream comprising purified hydrocarbon feed and process steam feed in the prereformer feed preheater and generating a heated combined stream; pre-reforming the heated combined stream from the prereformer feed preheater in the prereforming section and generating a first process gas stream; heating the first process gas stream in the process gas pre-heater and generating a heated first process gas stream feeding at least a portion of the heated first process gas stream, said oxygen feed and said burner steam feed to the autothermal reforming ATR section and generating a second process gas stream; feeding at least a portion of the high pressure boiler feed water to the steam drum and supplying a first boiler water stream; heat exchanging at least a portion of the second process gas stream with the first boiler water stream from said steam drum in the first waste heat boiler and generating a cooled second process gas stream and a first steam stream; feeding the cooled second process gas stream from the first waste heat boiler and the second process steam feed to the high temperature (HT) shift section and generating a third process gas stream; feeding the cooled third process gas stream to the second shift section and generating a fourth process gas stream; feeding the low pressure boiler feed water to the low pressure waste heat boiler and heat exchanging at least a portion of the low pressure boiler feed water with the fourth process gas stream from said second shift section; so as to provide a low pressure steam stream and a cooled fourth process gas stream; heat exchanging at least a first portion of the low pressure steam stream from the low pressure waste heat boiler with the third process gas stream from the high temperature (HT) shift section, in the low pressure steam superheater, so as to generate a low pressure superheated steam stream and a cooled third process gas stream; feeding at least a portion of the low pressure superheated steam stream to the alternator, and generating electrical power; feeding said cooled fourth process gas stream to syngas purification section so as to generate a dried fourth process gas stream and a process condensate; wherein the syngas purification section comprises, in order: a separator section, a pressure swing absorption (PSA) unit and a cryogenic CO2 removal unit; feeding the dried fourth process gas stream to the PSA unit to generate a hydrogen product stream, optionally hydrogen rich fuel stream(s) and a tail gas stream, feeding said tail gas stream from the PSA unit to the CO2 removal unit, so as to generate a CCh-rich stream, a carbon-containing ATR. recycle stream and an offgas fuel stream, feeding a first portion of the hydrogen product stream from the PSA unit, said nitrogen feed, and a portion of the boiler feed water, to the ammonia synthesis loop and generating a first ammonia-rich stream and a second steam stream.

[0045] In this process, the syngas stream generated from the first portion of the hydrogen product stream and said nitrogen feed, typically comprises hydrogen and nitrogen in a ratio of ca. 3: 1.

[0046] Specific embodiments

[0047] Figure 1 shows a layout of an ammonia plant according to the invention, with the following features: hydrocarbon feed (1) burner steam feed (2') a first process steam feed (2) a second process steam feed (7) oxygen feed (3) nitrogen feed (4) high pressure boiler feed water (8, 8A, 8B) low pressure boiler feed water (5) saturated high pressure steam stream(s) (111, 111A, 111B) feed pre-heater (91) pre-heated hydrocarbon feed (1') feed purification section (80) purified hydrocarbon feed (1") prereformer feed preheater (92) combined stream (81) comprising purified hydrocarbon feed (1") and process steam feed (2) heated combined stream (81') hydrogenation unit (82) sulfur removal unit (83) prereforming section (20) first process gas stream (21) process gas pre-heater (93) heated first process gas stream (21') autothermal reforming ATR. section (30) second process gas stream (31) steam drum (110) first boiler water stream (112) first waste heat boiler (40) steam superheater (75) cooled second process gas stream (31') first steam stream (41) high temperature (HT) shift section (50) third process gas stream (51)

[0048] LP steam waste heat boiler (310)

[0049] LP steam superheater (70) alternator (170) cooled third process gas stream (51', 51") low pressure superheated steam stream (71) second (e.g. low temperature (LT)) shift section (60) fourth process gas stream (61) cooled fourth process gas stream (61') fired heater (90) fuel stream (9) for the fired heater syngas purification section (100) syngas stream (107) comprising hydrogen and nitrogen,

[0050] CC -rich stream (151) process condensate (102) carbon-containing ATR. recycle stream (152) offgas fuel stream (153), a separator section (130) pressure swing absorption (PSA) unit (140) cryogenic CO2 removal unit (150) dried fourth process gas stream (131) hydrogen rich fuel stream (103) hydrogen product stream (104) tail gas stream (141) low pressure steam stream (311, 311A, 311B) ammonia synthesis loop (200) first ammonia-rich stream (201) fired steam superheater (120) superheated steam stream (s) (121A, 121B) ammonia reactor (240), compressor section (220) ammonia separator (230) waste heat boiler (251) effluent (241) from the ammonia reactor (240),

[0051] In figure 1, there is a separate steam drum in the loop (large plant capacities), but it could also have been a common steam drum for the front end and loop HP steam generation.

[0052] EXAMPLES

[0053] In both examples utilization of part of the latent heat available from LT shift converter outlet (stream 61) to the purification unit (unit 100) is shown. The differences between the two examples are described below:

[0054] Example 1 : LP steam flow of 75691 kg / h is generated in LP steam waste heat boiler (310) with the conditions 4 bar g and 152°C, the LP steam is following superheated in LP steam superheater 70 located between the HT and LT shift converters. With higher LP steam conditions (compared to example 2) more calories are wasted in the process gas cooler (air cooler located upstream of unit 100)~77.55 Gcal / h. Stream 61' is sent to unit 100 (130+ 140+150). In the table below stream conditions for streams 51, 61 and 61' are given. Table for example 1 :

[0055] Example 2 : LP steam flow of 107857 kg / h is generated in LP steam waste heat boiler (310) with the conditions 1.9 bar g and 132°C and part of the saturated LP steam is used in various preheaters. The rest of the LP steam is following superheated in LP steam superheater 70 with MP steam from the header. With lower LP steam conditions (compared to example 1) less calories are wasted in the process gas cooler (air cooler located upstream of unit 100)~13.63 Gcal / h. Stream 61' is sent to unit 100 (130+ 140+ 150). In the table below stream conditions for streams 61 and 61' are given. Table for example 2 :

[0056] The present invention has been described with reference to a number of aspects and a figure. However, the skilled person is able to select and combine various aspects within the scope of the invention, which is defined by the appended claims. All documents referenced herein are incorporated by reference.

Claims

CLAIMS1. An ammonia plant (A) said plant (A) comprising : a hydrocarbon feed (1); a burner steam feed (2'); a first process steam feed (2); a second process steam feed (7); an oxygen feed (3); a nitrogen feed (4); a high pressure boiler feed water (8); a low pressure boiler feed water (5); a feed pre-heater (91) being arranged to pre-heat the hydrocarbon feed (1) and to generate a pre-heated hydrocarbon feed (1'); a feed purification section (80), being arranged to hydrogenate and remove sulfur compounds from the preheated hydrocarbon feed (1'), and to generate a purified hydrocarbon feed (1"); a prereformer feed preheater (92) arranged to heat a combined stream (81) comprising purified hydrocarbon feed (1") and process steam feed (2) and to generate a heated combined stream (81'); a prereforming section (20) arranged to pre-reform the heated combined stream (81') from the prereformer feed preheater (92) and to generate a first process gas stream (21); a process gas pre-heater (93) arranged to heat said first process gas stream (21) and to generate a heated first process gas stream (21') an autothermal reforming ATR. section (30) arranged to receive at least a portion of the heated first process gas stream (21'), said oxygen feed (3) and said burner steam feed (2') and to generate a second process gas stream (31); a steam drum (110) arranged to receive at least a portion (8A) of the high pressure boiler feed water (8) and supply a first boiler water stream (112), a first waste heat boiler (40) arranged to heat exchange at least a portion of the second process gas stream (31) with the first boiler water stream (112) from said steam drum (110) and generate a cooled second process gas stream (31') and a first steam stream (41); a high temperature (HT) shift section (50) arranged to receive the cooled second process gas stream (31') from the first waste heat boiler (40) and the second process steam feed (7), and to generate a third process gas stream (51); a second shift section (60) arranged to receive the cooled third process gas stream (51') and generate a fourth process gas stream (61);a low pressure waste heat boiler (310) arranged to receive the low pressure boiler feed water (5), and heat exchange at least a portion of the low pressure boiler feed water (5) with the fourth process gas stream (61) from said second shift section (60); and to generate a low pressure steam stream (311) and a cooled fourth process gas stream (61'); a low pressure steam superheater (70) arranged to heat exchange at least a first portion (311A) of the low pressure steam stream (311) from the low pressure waste heat boiler (310) with the third process gas stream (51') from the high temperature (HT) shift section (50), so as to generate a low pressure superheated steam stream (71) and a cooled third process gas stream (51"); an alternator (170), said alternator (170) being arranged to receive at least a portion of the low pressure superheated steam stream (71), and to generate electrical power; a syngas purification section (100) comprising, in order: a separator section (130), a pressure swing absorption (PSA) unit (140) and a cryogenic CO2 removal unit (150); wherein the separator section (130) is arranged to receive said cooled fourth process gas stream (61') and generate a dried fourth process gas stream (131) and a process condensate stream (102), wherein the PSA unit (140) is arranged to receive the dried fourth process gas stream (131) and to generate a hydrogen product stream (104) and a tail gas stream (141), and wherein the CO2 removal unit (150) is arranged to receive said tail gas stream (141) from the PSA unit (140) and to generate a CC -rich stream (151), a carbon- containing ATR. recycle stream (152) and an offgas fuel stream (153), and an ammonia synthesis loop (200) arranged to receive at least a first portion (104A) of the hydrogen product stream (104) from the PSA unit (140), said nitrogen feed (4), and a portion (8B) of the boiler feed water (8), and to generate a first ammonia-rich stream (201) and a second steam stream (111).

2. The ammonia plant according to claim 1, wherein the second shift section is a low temperature (LT) or a medium temperature (MT) shift section, preferably a low temperature shift section.

3. The ammonia plant according to any one of the preceding claims, wherein said ammonia plant does not comprise a fired steam superheater (120).

4. The ammonia plant according to any one of the preceding claims, comprising a fired heater (90) and a fuel stream (9) for said fired heater, wherein at least one - and preferably all - of said feed pre-heater (91), prereformer feed preheater (92) and syngas pre-heater (93) comprise heater coil(s) within said fired heater (90).

5. The ammonia plant according to claim 4, wherein a second portion (104B) of the hydrogen product stream (104) from the PSA unit (140) is arranged to be fed as fuel to the fired heaters (90, 120).

6. The ammonia plant according to claim 4 or 5, wherein the PSA unit (140) is further arranged to generate a hydrogen rich fuel stream (103), and wherein at least a portion of said hydrogen rich fuel stream (103) is arranged to be fed as fuel to the fired heaters (90, 120).

7. The ammonia plant according to any one of claims 4-6, wherein at least a portion of the offgas fuel stream (153), is arranged to be fed as fuel to the fired heaters (90, 120), optionally in combination with a portion (107A) of the syngas stream (107).

8. The ammonia plant according to any one of the preceding claims, wherein the ammonia synthesis loop (200) comprises an ammonia reactor (240), a compressor section (220), an ammonia separator (230) and at least one waste heat boiler (251) and optionally a steam superheater (252), said at least one waste heat boiler (251) and optional steam superheater (252) being arranged downstream the ammonia reactor (240), wherein said portion of the boiler feed water (8) is arranged to be heat exchanged in said at least one waste heat boiler (251) with the effluent (241) from the ammonia reactor (240), and optionally said steam superheater (252), so as to generate said second steam stream (111).

9. The ammonia plant according to any one of the preceding claims, wherein a high pressure steam stream (11) is also arranged to be provided to the alternator (170).

10. The ammonia plant according to any one of the preceding claims, wherein the low pressure steam superheater (70) is arranged to heat a first portion (311A) of the low pressure steam stream (311) and wherein a second part (311B) of the low pressure steam stream (311) is arranged to heat one or more preheaters elsewhere in the ammonia plant.

11. The ammonia plant according to any one of the preceding claims, wherein the autothermal reforming ATR section (30) is arranged to receive at least a portion of the carbon-containing ATR recycle stream (152) at the inlet of said ATR section (30), suitably in admixture with the heated first process gas stream (21').

12. The ammonia plant according to any one of the preceding claims, further comprising a demineralised water (DMW) preheater and a process gas cooler arranged to further cool the cooled fourth process gas stream (61') upstream the separator section (130).

13. The ammonia plant according to any one of the preceding claims, wherein the cryogenic CO2 removal unit (150) comprises a cryogenic CO2 fractionation system, followed by at least one overhead (OHVD) PSA unit, and optionally a membrane separation unit arranged downstream the overhead (OHVD) PSA unit.

14. The ammonia plant according to any one of the preceding claims, wherein the cryogenic CO2 removal unit (150) is arranged to generate a further hydrogen product stream (105).

15. A process for generating ammonia in the ammonia plant (A) according to any one of the preceding claims, said process comprising the steps of: providing the plant according to any one of the preceding claims, pre-heating the hydrocarbon feed (1) in the feed pre-heater (91) and generating a pre-heated hydrocarbon feed (1'); hydrogenating and removing sulfur compounds from the preheated hydrocarbon feed (1') in the feed purification section (80), and generating a purified hydrocarbon feed (1"); heating a combined stream (81) comprising purified hydrocarbon feed (1") and process steam feed (2) in the prereformer feed preheater (92) and generating a heated combined stream (81'); pre-reforming the heated combined stream (81') from the prereformer feed preheater (92) in the prereforming section (20) and generating a first process gas stream (21); heating the first process gas stream (21) in the process gas pre-heater (93) and generating a heated first process gas stream (21') feeding at least a portion of the heated first process gas stream (21'), said oxygen feed (3) and said burner steam feed (2') to the autothermal reforming ATR. section (30) and generating a second process gas stream (31); feeding at least a portion of the high pressure boiler feed water (8) to the steam drum (110) and supplying a first boiler water stream (112); heat exchanging at least a portion of the second process gas stream (31) with the first boiler water stream (112) from said steam drum (110) in the first waste heat boiler (40) and generating a cooled second process gas stream (31') and a first steam stream (41); feeding the cooled second process gas stream (31') from the first waste heat boiler (40) and the second process steam feed (7) to the high temperature (HT) shift section (50) and generating a third process gas stream (51); feeding the cooled third process gas stream (51') to the second shift section (60) and generating a fourth process gas stream (61);feeding the low pressure boiler feed water (5) to the low pressure waste heat boiler(310) and heat exchanging at least a portion of the low pressure boiler feed water (5) with the fourth process gas stream (61) from said second shift section (60); so as to provide a low pressure steam stream (311) and a cooled fourth process gas stream (61'); heat exchanging at least a first portion (311A) of the low pressure steam stream(311) from the low pressure waste heat boiler (310) with the third process gas stream (51) from the high temperature (HT) shift section (50), in the low pressure steam superheater (70), so as to generate a low pressure superheated steam stream (71) and a cooled third process gas stream (51'); feeding at least a portion of the low pressure superheated steam stream (71) to the alternator (170), and generating electrical power; feeding said cooled fourth process gas stream (61') to syngas purification section (100) so as to generate a dried fourth process gas stream (131) and a process condensate (102); wherein the syngas purification section (100) comprises, in order: a separator section (130), a pressure swing absorption (PSA) unit (140) and a cryogenic CO2 removal unit (150); feeding the dried fourth process gas stream (131) to the PSA unit (140) to generate a hydrogen product stream (104), optionally a hydrogen rich fuel stream (103), and a tail gas stream (141), feeding said tail gas stream (141) from the PSA unit (140) to the CO2 removal unit (150), so as to generate a CC -rich stream (151), a carbon-containing ATR. recycle stream (152) and an offgas fuel stream (153), and optionally a further hydrogen product stream (105), feeding a first portion (104A) of the hydrogen product stream (104) from the PSA unit (140), said nitrogen feed (4), and a portion of the boiler feed water (8), to the ammonia synthesis loop (200) and generating a first ammonia-rich stream (201) and a second steam stream (111B).

16. The process according to claim 15, wherein the syngas stream (107) generated from the first portion (104A) of the hydrogen product stream (104) and said nitrogen feed (4), comprises hydrogen and nitrogen in a ratio of ca. 3: 1.

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