NL2031757B1

NL2031757B1 - Ammonia separation system for an ammonia synthesis loop.

Info

Publication number: NL2031757B1
Application number: NL2031757A
Authority: NL
Inventors: Van Zee Gerard
Original assignee: Proton Ventures B V
Priority date: 2022-05-02
Filing date: 2022-05-02
Publication date: 2023-11-13

Abstract

An ammonia separation system (1000) for separating ammonia from a first gas stream (120), Wherein the ammonia separation system (1000) comprises a recovery unit (200) and a sorption system (400), Wherein the sorption system (400) comprises an inlet (410), an outlet (420), and a plurality of functional units (450), wherein: the inlet (410) is configured to receive the first gas stream (120), each functional unit (450) comprises a first sorption bed (510), a second sorption bed (520), and a temperature control element (430), Wherein the first sorption bed (510) and the second sorption bed (520) comprise a sorption material (455) suitable for the sorption of ammonia, and Wherein each functional unit (450) is operable in a desorption mode and in a sorption mode, Wherein: in the desorption mode the functional unit (450) is configured to provide a desorption flow path from the inlet to the recovery unit (200) via the first sorption bed (510) and the second sorption bed (520); in the sorption mode the functional unit (450) is configured to provide a sorption flow path from the recovery unit (200) to the outlet (420) via the first sorption bed (510) and the second sorption bed (520), Wherein the temperature control element (430) is configured to control a sorption temperature of at least part of the sorption flow path between the first sorption bed (510) and the second sorption bed (520), during operation (i) a first subset (451) of the functional units (450) is operated in the desorption mode and (ii) a second subset (452) of the functional units (450) is operated in the sorption mode; the recovery unit (200) is configured to separate the first gas stream (120) into a recycle stream (210) and an ammonia product stream (220), and Wherein the recovery unit (200) is configured to provide the recycle stream (210) to the sorption system (400), and Wherein the recovery unit (200) is configured to provide the ammonia product stream (220) to a second outlet (230).

Description

Ammonia separation system for an ammonia synthesis loop.

FIELD OF THE INVENTION

The invention relates to an ammonia separation system. Further, the invention relates to an ammonia separation method. Further, the invention relates to a system comprising the ammonia separation system. Yet further, the invention relates to an ammonia synthesis method.

BACKGROUND OF THE INVENTION

Ammonia recovery is known in the art. For instance, US5968232A describes a process for separating ammonia from a gaseous solvent under conditions where a chemical potential of the ammonia dissolved in the gaseous solvent decreases as the density of the gaseous solvent increases, the process comprising the steps of passing the gaseous solvent containing the ammonia, the gaseous solvent being at a first density, through a bed of sorbent in a first direction so as to sorb the ammonia from the gaseous solvent onto the bed of sorbent while producing a purified gaseous solvent reduced in concentration of the ammonia, comprising acting upon a portion of the purified gaseous solvent so as to achieve a second density so that the portion of the purified gaseous solvent has an increased solvent capacity for the ammonia, comprising passing an amount of purified gaseous solvent at the second density through the bed of sorbent in a second direction opposite the first direction so as to desorb the ammonia from the bed of sorbent producing a gaseous solution of the ammonia dissolved in the amount of purified gaseous solvent, the amount of purified gaseous solvent at the second density being selected from the group consisting of the portion of the purified gaseous solvent at the second density and a purified gaseous solvent at the second density which is supplied from outside the process, and recovering the gaseous solution of the ammonia dissolved in the portion of purified gaseous solvent to form a recovered portion of the gaseous solution.

SUMMARY OF THE INVENTION

The Haber-Bosch process for the production of ammonia has been long established. Over the last decades, conditions under which ammonia may be suitably synthesized have been explored in detail. Further, there have been developments in processes and systems for extracting ammonia from gaseous mixtures.

The prior art may, for instance, describe systems and processes for synthesizing ammonia from a feed stream to provide an ammonia-comprising gaseous mixture, separating the gaseous mixture into an ammonia product stream and a recycle stream, and feeding the recycle stream back into the feed stream. However, substantial amounts of ammonia may remain in the recycle stream. Generally, however, it may be desirable for the ammonia product stream to comprise as much of the synthesized ammonia as possible. Further, the reintroduction of ammonia into the ammonia synthesis process (via the feed stream), may negatively affect the kinetics of the ammonia synthesis reaction as some product is already present. Hence, the presence of (substantial amounts of) ammonia in a recycle stream may reduce the single-pass efficiency of an ammonia synthesis loop.

Further, prior art systems may be (relatively) inefficient in heat management.

In addition, the prior art may describe systems comprising sorbent beds for the separation of gases, such as for the separation of ammonia from a gaseous mixture. However, in such systems the sorbent beds may not be continuously operated efficiently. In particular, while some of the sorbent beds may be sorbing or desorbing (or “regenerating”), other sorbent beds may be (essentially) idle.

Further, prior art systems may not be suitable for continuous operation. The modern demand for ammonia, such as for providing ammonia to a distribution network or for the large-scale production of ammonia, may, however, benefit from systems capable of being continuously operated. Prior art systems may further require relatively harsh pressure conditions, i.e., they may require a high operational pressure. This may be disadvantageous as large compressors may be required to achieve these high operational pressures. Further, the construction of such systems may require thick steel walls to withstand this high operational pressure.

Hence, it is an aspect of the invention to provide an alternative system for recovering ammonia, which preferably further at least partly obviates one or more of above- described drawbacks. It may further be an aspect of the invention to provide an alternative system for synthesizing ammonia, which preferably further at least partly obviates one or more of above-described drawbacks. The present invention may have as object to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

Hence, in a first aspect the invention may provide an ammonia separation system for separating ammonia from a first gas stream. In embodiments, the ammonia separation system (or “separation system”) may comprise a recovery unit. Further, in embodiments, the ammonia separation system may comprise a sorption system. Especially, the sorption system may comprise an inlet, an outlet, and a plurality of functional units. In further embodiments, the inlet may be configured to receive the first gas stream. Furthermore, each functional unit may comprise a first sorption bed. Especially, each functional unit may (also) comprise a second sorption bed. In addition, each functional unit may comprise a temperature control element. Hence, in embodiments, each functional unit may comprise a first sorption bed, a second sorption bed, and a temperature control element. Further, in embodiments, the first sorption bed and the second sorption bed may comprise a sorption material (or “sorbent material” or “sorbent”) suitable for the sorption of ammonia. Each functional unit, in embodiments, may be operable in a desorption mode and in a sorption mode.

In the desorption mode the functional unit may be configured to provide a desorption flow path for the first gas stream from the inlet to the recovery unit via the first sorption bed and the second sorption bed. Analogously, in the sorption mode the functional unit may be configured to provide a sorption flow path for the recycle stream (or “recycling stream”) from the recovery unit to the outlet via the first sorption bed and the second sorption bed. In embodiments, the temperature control element may be configured to control a sorption temperature of at least part of the sorption flow path between the first sorption bed and the second sorption bed, especially wherein the sorption temperature is selected from the range of < 100 °C. Especially, during operation of the ammonia separation system (1) a first proper subset of the functional units may be operated in the desorption mode and (ii) a second proper subset of the functional units may be operated in the sorption mode. Here, the term “proper subset” of functional units refers to a subset comprising at least 1 functional unit, but not all the functional units. Thus, the first proper subset may especially comprise one or more (but not all) functional units and the second proper subset may comprise the remaining functional units. Further, in embodiments, the recovery unit may be configured to separate the first gas stream into a recycle stream and an ammonia product stream. Especially, the recovery unit may be configured to provide the recycle stream to the sorption system. Additionally, in embodiments, the recovery unit may be configured to provide the ammonia product stream to a second outlet.

Note that the term “sorption” (or “sorb”) in this context may refer to adsorption or absorption of a gas onto a substrate, and analogously “desorption” (or “desorb”) may refer to releasing absorbed or adsorbed gas from a substrate. The term “sorption” (or “sorb”) may (also) refer to the accumulation of a gas on a substrate, and “desorption” (or “desorb”’) may (also) refer to removal of a gas from a substrate. Note that sorption comprises “chemisorption”, in which a gas is adsorbed on the substrate, especially involving a (reversible) chemical reaction with the formation of bonds between the sorbent material and the gas (that is adsorbed). An example of this may be the sorption of gas on a metal halide substrate.

Further, the term “sorption bed” (or “sorbent bed”) may herein refer to a confined space comprising, especially filled with, constituent sorbent material. Sorbent material in the sorption bed may especially be in the form of pellets, granules or small particles.

The shape and size of these particles may be selected to achieve a specific packing efficiency.

Further, the exposed surface area of sorbent material may influence the quantity of ammonia sorbed (or desorbed). Hence, the sorbent bed may comprise sorbent material with internal pores, thereby providing a relatively larger surface area of the sorbent material in the sorption bed. Further, the shape, size, polydispersity, and concentration of sorbent material in the sorbent bed may be chosen for its resistance to crushing and abrasion. Yet further, the sorption bed may be assembled to minimize dust build-up. In embodiments, gas may be flowed over the surface of the sorbent bed. In alternative embodiments, gas may (also) be flowed through the bulk of the sorbent material in the sorbent bed.

In specific embodiments, the invention may provide an ammonia separation system for separating ammonia from a first gas stream, wherein the ammonia separation system comprises a recovery unit and a sorption system, wherein the sorption system comprises an inlet, an outlet, and a plurality of functional units, wherein the inlet is configured to receive the first gas stream, wherein each functional unit comprises a first sorption bed, a second sorption bed, and a temperature control element, wherein the first sorption bed and the second sorption bed comprise a sorption material suitable for the sorption of ammonia, and wherein each functional unit is operable in a desorption mode and in a sorption mode, wherein in the desorption mode the functional unit is configured to provide a desorption flow path for the first gas stream from the inlet to the recovery unit via the first sorption bed and the second sorption bed, wherein in the sorption mode the functional unit is configured to provide a sorption flow path for the recycle stream from the recovery unit to the outlet via the first sorption bed and the second sorption bed, wherein the temperature control element is configured to control a sorption temperature of at least part of the sorption flow path between the first sorption bed and the second sorption bed, wherein during operation (i) a first proper subset of the functional units is operated in the desorption mode and (11) a second proper subset of the functional units is operated in the sorption mode, wherein the recovery unit is configured to separate the first gas stream into a recycle stream and an ammonia product stream, and wherein the recovery unit is configured to provide the recycle stream to the sorption system, and wherein the recovery unit is configured to provide the ammonia product stream to a second outlet.

The recovery system of the invention may provide the benefit that an increased proportion of ammonia in the first gas stream may end up in the ammonia product stream and, correspondingly, that the recycle stream comprises a reduced proportion of the ammonia, which may benefit a further ammonia synthesis process. In particular, the separation unit may provide 5 the recycle stream, already relatively low in ammonia content, to a functional unit operating in sorption mode such that ammonia is sorbed to the sorption beds in the functional unit, and such that a purified recycle stream is provided to the outlet. The purified recycle stream (or “purified stream” or “purified recycling stream”) may essentially have less ammonia than the (non- purified) recycle stream, such as at least 1 mol.% less ammonia, especially at least 2 mol.% less ammonia, such as at least 4 mol.% less ammonia. In further embodiments, the purified recycle stream may have at least 6 mol.% less ammonia than the (non-purified) recycle stream, especially at least 8 mol.% less ammonia, such as at least 10 mol.% less ammonia. In embodiments, the purified recycle stream may essentially have less ammonia than the (non- purified) recycle stream, such as at least 50 % less ammonia (than the recycle stream as provided to the functional unit), especially at least 65 % less ammonia, such as at least 80 % less ammonia.

In embodiments, the recycle stream may essentially comprise at most 16 mol % ammonia, such as at most 13 mol.% ammonia, especially at most 10 mol.% ammonia. In embodiments, the recycle stream may comprise at least 2 mol.%, such as at least 3 mol.%, especially at least 5 mol.% ammonia. The recycle stream may then be flowed (or “passed” or “led”) through the functional unit(s) along the sorption flow path to provide the recycle stream.

Thus, in embodiments, the purified recycle stream may comprise at most 5 mol.% ammonia, such as at most 2 mol.% ammonia, especially at most 1 mol.% ammonia. Further, in embodiments, the purified recycle stream may comprise at least 0.05 mol.%, such as at least 0.1 mol.%, especially at least 0.2 mol .% ammonia.

Once the functional unit has been loaded (see below), it may be switched to the desorption mode, wherein it receives the first gas stream, which is already relatively high in ammonia content, and may desorb the ammonia to the first gas stream, especially thereby providing an ammonia enriched first gas stream. The enriched first gas stream (or “ammonia enriched stream” or “ammonia enriched first gas stream”) may essentially have more ammonia than the (non-enriched) first gas stream, such as at least 5 mol.% more ammonia, especially at least 10 mol.% more ammonia, such as at least 20 mol.% more ammonia. As the sorption system comprises a plurality of functional units, at least part of the functional units may, during operation of the ammonia separation system, be operated in the sorption mode and at least part of the functional units may be operated in the desorption mode. Thereby, the ammonia separation system may facilitate continuous operation.

Note that the rate (i.e. per hour) at which ammonia is sorbed is not necessarily the rate at which ammonia may be desorbed. The rate of ammonia sorption and desorption may be dependent on factors such as temperature (of sorption material and the gas stream flowed over it), the composition of the sorption material, etc. For instance, typically, the ammonia separation system may be operated such that desorption (or “regeneration”) is faster than sorption. Hence, the amount desorbed into the first gas stream may vary over time as more desorption from a functional unit may take place upon switching the functional unit to the desorption mode than right before switching it back to the sorption mode. In embodiments, the number of functional units operated in the sorption mode may (during at least part of operation) differ from number of functional units operated in the desorption mode. This may facilitate providing continuous operation of the ammonia separation system when the rate of sorption and desorption are different.

The sorption and desorption of ammonia may be temperature-dependent. In particular, ammonia may sorb (or “accumulate”) to the sorption material at (relatively) low temperatures and may desorb (or “be removed”) from the sorption material at (relatively) high temperatures. In addition, the sorption of ammonia to the sorption material may be exothermic, resulting in heating of the recycle stream, which in turn may result in reduced downstream sorption. Hence, typically, the sorption efficiency of ammonia may decrease as an ammonia- containing gas passes through sorption material, which may result in a largely successive usage of sequentially arranged sorption beds. The ammonia separation system of the invention, however, provides temperature control between sorption beds (or between sorption elements; see below), and may thus simultaneously expose each sequentially arranged sorption bed along the sorption flow path to a sorption temperature suitable for the sorption of ammonia, resulting in a more efficient usage of the sorption material in time.

Hence, the present invention may provide an ammonia separation system that may be operated simultaneously in two modes, such that a part of the sorption system sorbs ammonia and simultaneously another part of the sorption system desorbs ammonia. Hence, as aresult, the sorption material saturated in ammonia may be used to desorb ammonia and enrich ammonia content of a stream before recovery (of ammonia) from that stream, and the sorption material that 1s (fully) regenerated may be used to sorb ammonia from a stream comprising ammonia. By the simultaneous operation in this manner, the sorption materials may be continuously sorbed and desorbed facilitating continuous operation of the ammonia separation system.

In embodiments, the ammonia separation system or (“ammonia recovery system”) for separating ammonia from a first gas stream may comprise a recovery unit (or “separation unit”) and a sorption system. The recovery unit may be used to recover ammonia from a stream comprising ammonia, hence providing an ammonia product stream (or “ammonia stream”).

The skilled person will be aware of the distinction between adsorption and absorption. During absorption, the gas that is “absorbed” on a substrate involves the molecules or atoms of the gas penetrating the volume of the substrate by which they are absorbed. This is different from adsorption, where the gas that is “adsorbed” on a substrate involves the adhesion of gas molecules to the surface of the substrate. The substrate (or “sorbent”) referred to here is a material that is configured to sorb (or desorb) a gas on either its surface or within its volume.

Hence, in embodiments, the ammonia separation system may comprise a sorption system, which may be configured to sorb (and desorb) ammonia. In further embodiments, the sorption system may comprise an adsorption system configured to adsorb ammonia, i.e., the sorption material may comprise an adsorption material (for ammonia). In further embodiments, the sorption system may comprise an absorption system configured to absorb ammonia, i.e., the sorption material may comprise an absorption material (for ammonia).

Especially, the sorption system may comprise an inlet, an outlet, and a plurality of functional units.

The number of functional units comprised by the sorption system may be configurable. The sorption system may, in embodiments, have at least 2 functional units, or especially at least 3 functional units, such as at least 4 functional units. The configurable number of functional units may provide the advantage of improving the extent of ammonia sorbed (or desorbed) i.e. having more functional units may increase the volume of the sorbent available. Additionally, this may also provide the advantage of scaling up the sorption system i.e. more volume of the first gas stream (comprising ammonia) may be provided to the sorption system.

Further, in embodiments, the inlet may be configured to receive the first gas stream. The first gas stream (comprising ammonia) may be provided to the sorption system by means of the inlet, which may then be flowed (or “passed”) through one or more functional units to the outlet.

The functional units comprised by the sorption system, in embodiments, may (each) comprise a first sorption bed, a second sorption bed, and a temperature control element.

The sorbent beds may especially be beds comprising a sorption material. Especially, the first sorption bed and the second sorption bed may comprise a sorption material suitable for the sorption of ammonia. The terms “first” and “second” used to refer to the sorption beds are used in particular to distinguish between the two sorption beds and are not necessarily an indication of the order in which the sorption beds are arranged. Further, this may apply to embodiments comprising 3 or more sorption beds. Hence, the first gas stream or the recycle stream may be flowed (to the separation unit or the outlet, respectively) via the one or more sorption beds comprised by the functional unit. For example, in embodiments, the first gas stream or the recycle stream may first be flowed through the first sorption bed and subsequently through the second sorption bed. And, in alternative embodiments, the first gas stream or the recycle stream may be flowed through the second sorption bed and subsequently through the first sorption bed.

Yet further, the flow of the first gas stream and/ or the recycle stream may be directed by a set of on-off valves. Hence, in the same embodiment, the first gas stream or the recycle stream may be flowed through the functional unit along a flow path where the first gas stream or the recycle stream: (i) first contacts the first sorption bed and subsequently the second sorption bed, or (ii) first contacts the second sorption bed and subsequently the first sorption bed. Hence, in embodiments, the first gas stream or the recycle stream may be flowed via the first sorption bed and the second sorption bed.

Each functional unit, in embodiments, may be operable in a desorption mode and in a sorption mode. Sorption leads to loading of the sorption beds (first sorption bed and the second sorption bed) with ammonia. During continuous operation, the sorption of ammonia on the sorption beds may lead to saturation of the sorption beds with ammonia, thus resulting in a decline in further sorption. Here, the term “loading” refers to the sorbing of ammonia by the sorption material. Hence, the sorption beds may have to be desorbed for further operation.

The sorption system may, in embodiments, overcome this issue by operating the functional units (comprising the sorption beds) in the sorption mode (configured to sorb ammonia) and the desorption mode (configured to desorb ammonia) alternatingly.

Especially, in the desorption mode the functional unit may be configured to provide a desorption flow path for the first gas stream from the inlet to the recovery unit via the first sorption bed and the second sorption bed. The desorption flow path may be a path along which ammonia is desorbed from the sorption beds in the functional unit. The desorbed ammonia (from the first sorption bed or the second sorption bed in the functional unit) may essentially be desorbed into the stream being flowed through the functional unit, which in embodiments, may be the first gas stream. Thus, the first gas stream (comprising ammonia) flowed along the desorption flow path may be enriched using the desorbed ammonia.

Analogously, in embodiments, the functional unit operated in a sorption mode may be configured to provide a sorption flow path for the recycle stream from the recovery unit to the outlet via the first sorption bed and the second sorption bed. Hence, similarly, in the sorption mode the functional unit may be configured to provide a sorption flow path for the recycling stream from the inlet to the outlet via the first sorption bed and the second sorption bed. In the sorption mode, the sorption beds may be configured to sorb ammonia from a stream comprising ammonia i.e. from the recycle stream.

The sorption material may comprise any sorption material suitable for the sorption of ammonia. For instance, in embodiments, the sorption material may comprise a metal halide on an inert porous granular carrier. Especially, the metal halide may be selected from a group comprising halides of zinc, manganese, iron, cobalt, nickel, magnesium, strontium and calcium. Especially, the halide may be selected from the group comprising Cl, Br, and F. In specific embodiments, the metal halide may, for example, be selected from the group comprising MgCl, CaCl, CaBr2, SrCl: and SrBr:. For example, in embodiments, metal halides such as Mg(NHz)sCl, and Sr(NH3)Cl: may be used as sorption material. Hence, in embodiments, the sorption material may comprise a metal halide, especially a metal halide selected from the group comprising Mg(NH:)sCl: and Sr{(NH;)sCb. Yet further, mixed metal halides may be used. Here, “mixed metal halides” refers to a combination of metals in the crystal lattice of a single chemical species, such as in ABy(NH3,)C,D;, where A and B represent metallic ions, C and D represent elements from the halide group, and x,y, z, n & 1 indicate stoichiometric ratios. Hence, in embodiments, the sorption material may comprise

AB(NH3,)C;D;. Here, A and/or B may be selected from the group comprising Li, Na, K, Rb,

Cs, Mg, Ca, Sr, Ba, Mn, Fe, Ni, Co, Cu, and Zn. Further, C and/or D may be selected from the group comprising Cl, Br, I. The stoichiometric ratios x and y may be in the range 0-1, n may be in the range 1-8, and z and 1 may be in the range 0-3. In further embodiments, the sorption material may comprise a zeolite. The term “zeolite” may herein refer to a family of hydrated aluminosilicate minerals that contain alkali and alkaline-earth metals. The zeolite may, in embodiments, be selected from the group comprising analcime, chabazite, clinoptilolite, heulandite, natrolite, phillipsite, and stilbite.

Generally, a sorption material may work in dependence of a temperature, i.e. the sorption material may sorb (or desorb) a gas within a certain temperature range. Typically,

the sorption material may desorb a gas (such as ammonia) at (relatively) high temperatures and may sorb gases at (relatively) low temperatures. The temperature range above (or below) which desorption (or sorption) takes place may depend on the sorption material. Hence, the sorption temperature may be selected based on the sorption material.

Hence, in embodiments, the sorption system may comprise a temperature control system, which may further comprise one or more temperature control elements. In particular, each functional unit may comprise a temperature control element of the one or more temperature control elements, i.e., the one or more temperature control elements may be arranged functionally coupled with the functional units. The temperature control element (of a functional unit) may, in embodiments, (be configured to) control a sorption temperature of at least part of the sorption flow path between the first sorption bed and the second sorption bed.

Hence, in embodiments, the temperature control system may (be configured to) control a sorption temperature of at least part of the sorption flow path between the first sorption bed and the second sorption bed (of each functional unit).

In embodiments, the ammonia separation system may comprise one or more sensor elements. Especially, the sorption system may comprise the one or more sensor elements. Sensor elements may, in embodiments, comprise a temperature sensor. In further embodiments, the sensor elements may comprise an infrared sensor. In further embodiments, the sensor elements may comprise a photo-acoustic sensor. Further, the sensor elements may be configured along the sorption flow path. Especially, the sensor elements may be configured downstream of the sorption beds. In embodiments, a sensor element may be arranged downstream of the first sorption bed or the second sorption bed. Hence, in embodiments, the sensor element may be configured downstream of the first sorption bed, such as between the first sorption bed and the second sorption bed. Further, in embodiments, the sensor element (such as a second sensor element) may be configured downstream of the second sorption bed.

Further, in embodiments comprising 3 or more sorption beds, 3 or more sensor elements may be configured downstream of each sorption bed, i.e., a respective sensor element may be arranged downstream of each sorption bed along a flow path, such as along the sorption flow path, or such as along the desorption flow path. Alternatively, the ammonia separation system may comprise fewer sensor elements than there are sorption beds in a functional unit.

The sensor elements may be used to determine the temperature of a gas stream flowing along the flow path (such as the sorption flow path). Especially, the temperature of the gas stream (such as the recycle stream) at the location where the one or more sensor elements are configured. As indicated above, the sorption by the sorption material may be temperature dependent. In the sorption mode, the sorption material may sorb ammonia from the recycle stream flowed over the sorption material comprised in one or more sorption beds. The sorption of ammonia on the sorption material 1s an exothermic process i.e. heat is released in the process of sorbing a gas by the sorption material. This may essentially heat the recycle stream as well as the sorption material. The sorption material may (essentially) sorb ammonia below a threshold temperature suitable for sorption. Hence, keeping the temperature of the sorption material below the threshold temperature may facilitate sorption (such as sorption of ammonia on the sorption material).

In embodiments, the saturation of the sorption material comprised by one or more sorption beds in the functional unit may be determined based on the temperature of the sorption material. When the sorption material is fully saturated with ammonia, the sorption material may be unable to (further) sorb ammonia i.e. the sorption material is saturated. As a consequence, the exothermic process may (essentially) no longer take place and (essentially) no further heat may be released. Hence, by configuring the sensor element (such as a temperature sensor) downstream of a sorption bed, it may be possible to determine the saturation of the sorption bed. Hence, in embodiments, the one or more sensor elements may be configured downstream of the one or more sorption beds.

In particular, in embodiments, the functional unit may comprise a plurality of sorption beds (such as the first sorption bed and the second sorption bed), which may especially be sequentially arranged along the sorption flow path. In such embodiments, the sorption system may comprise a sensor element, especially a temperature sensor, arranged downstream of the plurality of sorption beds with respect to (or “along””) the sorption flow path. In particular, the sensor element may be configured to detect a concentration-related parameter indicative of the concentration of ammonia in the (purified) recycle stream, and especially to provide a concentration-related signal to the control system. As saturation of the sorption material results in (essentially) no further sorption of ammonia, the concentration-related parameter, detected downstream of the sorption beds, may be indicative that the sorption beds are (close to being) saturated. Hence, detection of the concentration-related parameter may facilitate switching functional units between the sorption mode and the desorption mode in a timely fashion.

The term “concentration-related signal” may herein refer to a signal that is related to the detected ammonia concentration. In particular, the concentration-related signal may comprise raw and/or processed data related to the (detected) ammonia concentration. As described above, the temperature of the (purified) recycle stream may be indicative of the ammonia concentration in the (purified) recycle stream as sorption of ammonia results both in a decreased ammonia concentration and in an increased temperature.

In embodiments, the ammonia separation system, especially the control system, may be configured to control, especially to switch, the operational modes of the functional units based on the concentration-related signal. Essentially, the ammonia separation system, especially the control system, may be configured to switch a functional unit to the desorption mode when detecting that the functional unit is (nearly) saturated.

In further embodiments, the sensor element may comprise a temperature sensor configured to determine a temperature of the (purified) recycle stream downstream of the second subset of functional units, such as downstream of the first sorption beds and the second sorption beds of the functional unit(s) operated in the sorption mode, and to provide a temperature-related signal to the control system. In such embodiments, the control system may be configured to switch the operational modes of (at least part of) the first subset of functional units and (at least part of) the second subset of functional units when the purified recycle stream has a temperature (detected by the sensor element) of at least 50 °C, such as at least 60 °C, especially at least 80 °C. In further embodiments, the control system may be configured to switch the operational modes of (at least part of) the first subset of functional units and (at least part of) the second subset of functional units when the purified recycle stream has a temperature (detected by the sensor element) of at most 120 °C, such as at most 100 °C, especially at most 80 °C. In particular, in embodiments, the control system may be configured to switch the operational modes of (at least part of) the first subset of functional units and (at least part of) the second subset of functional units when the purified recycle stream has a temperature (detected by the sensor element) selected from the range of 50 — 120 °C, such as from the range of 50 — 100 °C, especially from the range of 50 — 80 °C.

The phrase “switching the operational modes of the functional units” and similar phrases herein may refer to switching the functional units from the sorption mode to the desorption mode and vice versa.

In specific embodiments, the sensor element may comprise a temperature sensor, and the ammonia separation system, especially the control system, may be configured to switch the operational modes of the first functional unit and the second functional unit when the purified recycle stream has a temperature (detected by the sensor element) of at least 50 °C, such as at least 60 °C, especially at least 70 °C. Hence, in embodiments, the control system may be configured to switch the operational modes of the first functional unit and the second functional unit when the purified recycle stream has a temperature (detected by the sensor element) of at most 120 °C, such as at most 100 °C, especially at most 80 °C.

In embodiments, during operation of the sorption system (i) a first proper subset of the functional units may be operated in the desorption mode and (ii) a second proper subset of the functional units may be operated in the sorption mode. This facilitates cycling between the two modes of operation for individual functional units, such that the sorption system may be continuously operated under both the sorption and desorption modes. In the sorption mode, ammonia may be continuously sorbed from the recycling stream (thus saturating the sorption material in the sorbent beds) and in the desorption mode ammonia may be continuously desorbed into the first gas stream (thus regenerating the sorption material). Thus, in embodiments, by operating the functional units in the sorption mode and desorption mode, a proper subset of the functional units may be regenerated (desorbing of ammonia) while another proper subset of the functional units may be saturated (sorbing of ammonia). This provides the advantage of continuous operation of the sorption system, by switching the saturated sorption material with the regenerated sorption material. In embodiments, this may be achieved by alternating the mode of operation of the functional units between the sorption mode and the desorption mode. Further, in embodiments, the sorption system may comprise control means, such as a series of on-off valves, configured at the unit inlet and the unit outlet of the functional units, that may allow the streams (first gas stream and the recycling stream) to be interchanged between the functional units. This provides the advantage of altering the mode of operation of the functional units without the requirement for physically altering any components or elements of the sorption system.

In embodiments, the recovery unit may be configured to separate the first gas stream into the recycle stream and an ammonia product stream. Especially, the recovery unit may separate ammonia as a liquid from the first gas stream. The first gas stream may, in embodiments, be separated into the ammonia product stream (comprising liquid ammonia) and the recycle stream (comprising the remainder gases which (also) comprises ammonia). Further, in embodiments, the recovery unit may be configured to provide the recycle stream to the sorption system, and yet further, the recovery unit may be configured to provide the ammonia product stream to the second outlet.

In embodiments, the sorption system may comprise a first functional unit and a second functional unit. Especially, in a first operational mode of the sorption system, the first functional unit may be operated in the sorption mode and the second functional unit may be operated simultaneously in the desorption mode. In an embodiment comprising only two functional units, one of them (such as first functional unit) may be operated in the sorption mode and the other (such as the second functional unit) may be operated simultaneously in the desorption mode. The simultaneous operation of the functional units in the sorption mode and the desorption mode provides the advantage of regenerating the sorption material in a functional unit, even as the sorption material in the other functional unit is saturated. This may provide the advantage of continuously operating the sorption system, as opposed to a conventional system where the operation of the sorption system may have to be halted while the sorption material is regenerated. Additionally, in embodiments, the sorption system may be operated in a second operational mode, where the first functional unit may be operated in the desorption mode and the second functional unit may be operated in the sorption mode. The second operational mode 1s analogous to the first operational mode, wherein the difference lies in altering the mode of operation of the functional units (i.e. sorption mode and desorption mode). The sorption system may, in embodiments, (be configured to) essentially switch between the first operational mode and the second operational mode. The on-off valves comprised by the sorption system may, in embodiments, be used to switch between the two operational modes. In particular, in further embodiments, the system may comprise a control system (see below) configured to switch the operational modes of the functional units by controlling control means, such as by controlling one or more valves, especially by controlling on-off valves.

Further, in embodiments, the ammonia separation system, especially the sorption system, may (be configured to), especially in the first operational mode, operate the first proper subset of the functional units in the sorption mode and the second proper subset of the functional units in the desorption mode simultaneously. Analogously, the ammonia separation system, especially the sorption system, may (be configured to), especially in a second operational mode, operate the first proper subset of the functional units in the desorption mode and the second proper subset of the functional units in the sorption mode simultaneously.

In embodiments, the temperature control element may be configured to cool the recycle stream between the first sorption bed and the second sorption bed along the sorption flow path. The sorption material may sorb or desorb ammonia in dependence of the temperature. Hence, the recycle stream may, in embodiments, beneficially be cooled to a temperature lower than the sorption temperature for the sorption of ammonia to facilitate sorption in both sorption beds. Hence, in embodiments, the temperature control element may be configured to cool the recycle stream between the first sorption bed and the second sorption bed. The recycle stream may, in embodiments, be provided by the recovery unit after the recovery of ammonia (from the first gas stream).

Further, cooling water may be used to lower the temperature of the sorption beds (comprised by the functional units). Especially, cooling water may be brought into contact with the functional units comprising the sorption beds, so as to lower their temperature, such as to reduce their temperature by 5 °C, especially by 10 °C, such as by 20 °C. Hence, in embodiments, the temperature control element may be configured to control the rate of flow of cooling water over the functional units comprising the sorption beds. In alternative embodiments, coolants other than water may also be used to cool the sorption beds. For example, cooling fans may be configured to blow air over the sorption beds. Hence, the temperature control element may cool the sorption beds, especially, the temperature control element may cool the sorption beds in dependence of a sensor element signal.

In embodiments, each functional unit may comprise a first sorption element and a second sorption element. Especially, the first sorption element may comprise the first sorption bed, such as a plurality of first sorption beds, and the second sorption element may comprise the second sorption bed, such as a plurality of second sorption beds. In embodiments, the first sorption element and the second sorption element may especially be physically separated.

Further, in such embodiments, the temperature control element may be configured to control the sorption temperature of at least part of the sorption flow path between the first sorption element and the second sorption element. Cooling between sorption elements, rather than between sorption beds within sorption elements, may be preferable as providing cooling within a sorption element may provide mechanical issues.

In further embodiments, (at least part of) the functional units may comprise three or more (respective) sorption elements. A plurality of sorption elements may provide the advantage of increasing the amount of ammonia sorbed from the recycling stream. Further, in embodiments, the temperature control system may comprise a plurality of temperature control elements, especially wherein each temperature control element is configured between (each set of two) respective sorption elements, and especially wherein each temperature control element may be configured to work in dependence of the one or more sensor elements.

In embodiments, the sorption temperature may be selected from the range of < °C, such as < 35 °C, especially < 30 °C. Therefore, (at least part of) the functional unit operated in the sorption mode may be cooled, such that the temperature along the sorption flow path between the first sorption element and the second sorption element is at a temperature equal to or lower than 40 °C, such as 35 °C, especially 30 °C.

Similarly, in the desorption mode, the temperature control element may be configured to control a desorption temperature of at least part of the desorption flow path between the first sorption element and the second sorption element. Similar to a sorption temperature for ammonia, the functional units (operated in the desorption mode) may (also) be operated at a suitable desorption temperature. Sorption material may desorb ammonia at (relatively) high temperatures. Especially, in embodiments, the desorption temperature may be selected from the range of 100-650 °C, such as from the range of 200-550 °C, especially from the range of 300-450 °C. Especially, the temperature control element may heat the first gas stream to a temperature of at least 250 °C, such as at least 300 °C, especially at least 400 °C.

In embodiments, the recovery unit may comprise a condensation unit configured to separate ammonia from the (ammonia enriched) first gas stream via condensation of the ammonia. Ammonia may have a condensation temperature of -33.6 °C at atmospheric pressure.

However, it is well known to the person skilled in the art that the condensation temperature may vary in dependence of pressure. For example, ammonia may have a condensation temperature of 25 °C at 10 bar.

In embodiments, the recovery unit may comprise a plurality of heat exchangers for precooling the first gas stream. Especially, the heat exchangers may be air or water cooled.

The enriched first gas stream may, in embodiments, be flowed along a path cooled by one or more heat exchangers. The one or more heat exchangers may provide the advantage of cooling the first gas stream to subsequently lower temperatures. The first gas stream may, in embodiments, be flowed through the desorption flow path (which is operated at high temperatures) and thus, may be provided at a high temperature. The one or more heat exchangers may cool the first gas stream, especially to a (suitable) temperature above the condensation temperature of ammonia (i.e. a temperature higher than the condensation temperature of ammonia), such as < 60 °C above the condensation temperature, especially < 50 °C, such as <40 °C. In embodiments, the recovery unit may be configured to (further) cool the first gas stream to a temperature below the condensation temperature of ammonia (especially downstream from the heat exchangers).

Recovery (or “separation”) of ammonia by condensation may be particularly suitable in the context of the present invention. In particular, condensation may involve (substantially) cooling the first gas stream to liquify the ammonia, thereby providing an ammonia product stream and a recycle stream. The recycle stream may thus also be (relatively) cold, which may facilitate the sorption of ammonia to the sorption material.

Further, in embodiments, the recovery unit may comprise a separator vessel, to which the first gas stream may be provided. Therefore, in embodiments, ammonia may be recovered as liquid ammonia from the first gas stream in the separator vessel by means of condensation. Hence, in embodiments, the recovery unit may separate ammonia from a gas stream (such as the first gas stream) by cooling the stream to a temperature lower than the condensation temperature of ammonia.

The ammonia separation system may be particularly beneficial in the context of an ammonia synthesis system, especially for an ammonia synthesis system configured to provide a continuous ammonia synthesis loop. Such ammonia separation system may especially operate at (relatively) mild operating conditions, such as with regards to pressure.

Hence, the present invention not only provides a method for the recovery of ammonia but also a method for the synthesis of ammonia (see below). In the synthesis of ammonia by the Haber-Bosch process, the mixture of gases comprising ammonia also comprises other gases such as dinitrogen, dihydrogen, byproducts of the reaction and trace amounts of other impurities. In the present invention, the synthesis and recovery of ammonia may be integrated in a single ammonia synthesis loop. In particular, the method for synthesis of ammonia benefits from the use of the separation method i.e. the unreacted gases such as dinitrogen and dihydrogen are flowed back (through the sorption system) to the feed stream or the reactor. Hence, using the method for recovery of ammonia, there may be less wastage of reactants. Therefore, improving the efficiency of the synthesis method. Additionally, the method of synthesis of ammonia provides the first gas stream i.e. a stream comprising ammonia at a high temperature (exiting the reactor). The desorption of ammonia may be temperature dependent. By providing a heated first gas stream, minimal to no additional heat may be required to operate the functional units in desorption mode. Hence, the synthesis method may provide the advantage of improving the efficiency of the separation method. Thus, the synthesis and the recovery of ammonia may work synergistically (or complementarily) in a manner that improves the efficiency of both.

In another aspect, the invention may provide a system comprising the ammonia separation system. The system may especially be for ammonia synthesis. In embodiments, the system may comprise a reactor and a feed supply (or “feed supply system”). Especially, the reactor may comprise an ammonia synthesis catalyst. Further, in embodiments, the feed supply may be configured to provide a feed stream to the reactor. The feed stream may, in embodiments, comprise dihydrogen and dinitrogen. Moreover, in embodiments, the outlet (of the ammonia separation system) may be configured to provide the recycle stream to the feed supply, the reactor, or both. Especially, the reactor may be configured to receive the feed stream, and to provide the first gas stream to the inlet.

Reactors are well known in the art and the skilled person will be aware that the reactor may be an enclosed chamber with one or more inlets and one or more outlets and may be configured to carry out a chemical reaction with (or without) the supply of, for instance, fuel and/or heat. In embodiments of the system, the reactor may comprise one or more reactor inlets and one or more reactor outlets. Especially, the reactor may be configured for the synthesis of ammonia.

Arrangements and methods for the synthesis of ammonia may be known in the art. Ammonia may, for instance, be synthesized by the Haber-Bosch process or variations of such. The term “Haber-Bosch process” may herein refer to a process for reacting dinitrogen and dihydrogen over an ammonia synthesis catalyst at a high temperature and pressure. In this process, dinitrogen and dihydrogen may be reacted according to the equation N2(g)+3Ha(g) == 2NHs(g). Hence, in embodiments, the reactor may have an inlet for receiving the feed stream, which may comprise dinitrogen and dihydrogen. Further, the reactor may comprise a reactor outlet, from which ammonia (produced by reacting dinitrogen and dihydrogen) may be provided. In particular, the reactor outlet may be configured to provide a first gas stream comprising ammonia and (unreacted) dinitrogen and dihydrogen.

In embodiments, the feed supply may comprise additional elements to facilitate providing the feed stream. In embodiments, the feed supply may comprise a storage system.

Especially, the storage system may comprise storage tanks or cylinders which may store (compressed) dinitrogen and dihydrogen. In embodiments, the feed supply may comprise a dinitrogen feed supply and/or a dihydrogen feed supply, especially at least a dinitrogen feed supply, or especially at least a dihydrogen feed supply. In specific embodiments, the dinitrogen and dihydrogen may be provided directly from a network for providing these gaseous streams, such as from a distribution network or an alternative process for providing dinitrogen and/or dihydrogen.

Another benefit of this configuration may be the more efficient use of heat in the system i.e. the heat from an exothermic ammonia synthesis reaction may be used to facilitate desorption. By desorption using the heat from the first gas stream, ammonia may accumulate in the first gas stream before condensation, which may further facilitate operating an ammonia synthesis loop at (much) milder pressure conditions.

In embodiments, the reactor may be configured to receive the feed stream comprising dihydrogen and dinitrogen. Especially, the dihydrogen and dinitrogen may be reacted in the reactor at a pressure of at least 50 bar and a temperature of at least 250 °C over an ammonia synthesis catalyst to provide the first gas stream. The temperature at which the dinitrogen and dihydrogen may be reacted may depend on the ammonia synthesis catalyst. For example, an iron-based catalyst may typically operate at a temperature of at least 350 °C.

Hence, in embodiments, during operation, dinitrogen and dihydrogen may be reacted at a temperature of at least 250 °C, such as at least 300 °C, especially at least 350 °C.

Especially, the first gas stream may comprise ammonia, such as at least 8 mol .%, such as at least 10 mol.%, especially at least 15 mol .%, such as at least 20 mol .%, especially at least 23 mol.%. In further embodiments, the first gas stream may comprise at most 40 mol.% ammonia, such as at most 30 mol.% ammonia, especially at most 25 mol.% ammonia. In embodiments, the first gas stream may be flowed through the functional unit(s) along the desorption flow path. Thereby, the first gas stream may be enriched in ammonia content to provide an enriched first gas stream. Hence, in embodiments, the (enriched) first gas stream may comprise ammonia, such as at least 13 mol.%, such as at least 18 mol.% ammonia, especially at least 23 mol.%, such as at least 35 mol.%, especially at least 45 mol.%. That is, in embodiments, the content of ammonia in the first gas stream may be increased by at least 5 mol.%, such as at least 10 mol.%, especially at least 15 mol.%, thereby providing an enriched first gas stream.

Further, the first gas stream may (also) comprise unreacted dinitrogen, dihydrogen, and trace amounts of other reaction products. In embodiments, the sorption system along the desorption flow path may enrich the first gas stream i.e. the ammonia content in the first gas stream may be increased. Further, the recovery unit may separate the ammonia from the first gas stream to provide the recycling stream comprising the unreacted dinitrogen, dihydrogen, (unrecovered) ammonia and other trace products. Furthermore, the recycle stream may be flowed through a sorption path, where ammonia may be removed from the recycle stream. Hence, the (purified) recycle stream may essentially comprise unreacted dinitrogen and dihydrogen. Therefore, in embodiments, the recycle stream (comprising unreacted dinitrogen and dihydrogen) provided at the outlet (of the sorption system) may be provided to the feed stream, or to the reactor inlet, or both. This may provide the advantage of improving the efficiency of the system by reusing the unreacted dihydrogen and dinitrogen. Further, in embodiments, the system may comprise additional elements (for ex: scrubbers, dryers, deoxizers, etc) for the removal of impurities or undesired biproducts produced during ammonia synthesis.

Hence, the system comprising the ammonia separation system may be configured in a synthesis loop. In embodiments, the feed supply may be configured to provide a feed stream to the reactor, which may provide the first gas stream to the sorption unit, which may then provide the (ammonia enriched) first gas stream to the recovery unit, which may provide a recycle stream back to the sorption system, which may then provide the (purified) recycle stream back to the reactor or the feed supply. Thus, completing the synthesis loop for the production and recovery of ammonia.

Further, in embodiments, the system may comprise a second temperature control element. Especially, the second temperature control element may be configured to heat the feed stream before the feed stream is provided to the reactor. Especially, the feed stream may be heated to a temperature in the range of 100-300 °C, such as in the range of 150-280 °C, especially in the range of 285-315 °C. The reaction of dihydrogen and dinitrogen according to the Haber-Bosch process may be carried out typically in the temperature range of 250-600 °C, such as in the range of 300-500 °C. Hence, in embodiments, the system may comprise a heater to heat the feed stream to a temperature in the range of 200-600 °C, such as in the range of 250- 500 °C, especially in the range of 300-450 °C, such as in the range of 350-400 °C. In specific embodiments, the heater may be an electrical heater. Hence, in embodiments, the second temperature control element may be configured to control the heater (comprised by the system and configured to heat the feed stream). The temperature at which the feed stream is provided to the reactor, especially to a catalyst bed comprised by the reactor, may be selected to facilitate the production of ammonia.

In embodiments, the feed stream may be provided to the reactor and the dinitrogen and dihydrogen comprised by the feed stream may be reacted in the reactor.

Especially, no further heating may be provided to the reactor during operation. The reaction of dinitrogen and dihydrogen to ammonia is an exothermic reaction, and the heat released from the reaction may facilitate further reaction of dinitrogen and dihydrogen with no additional heat supplied externally. Further, the reaction of dinitrogen and dihydrogen to produce ammonia may, for example, raise the temperature within the reactor to a temperature in the range 300- 400 °C.

Further, in embodiments, the (heated) feed stream may be provided over the catalyst bed comprised by the reactor. Especially, the reactor may comprise a catalyst bed comprising the ammonia synthesis catalyst. Hence, in embodiments, the feed stream may be provided over the ammonia synthesis catalyst at a temperature in the range 300-400 °C.

During the startup of the reactor, the temperature within the reactor may be insufficient to continuously sustain the reaction for the production of ammonia. Hence, in embodiments, the reactor may comprise one or more heating elements. Further, in embodiments, the heating elements may be electrical heating coils or heat exchangers. The heating elements may facilitate initiating the ammonia synthesis reaction. These heating elements may be configured to (be) turn(ed) off during continued operation (after the startup).

Particularly, electrical heating coils may be advantageous to use in small scale reactors.

However, the heat exchangers may be preferred for larger scale reactors, such as for large-scale industrial production of ammonia.

The ammonia synthesis catalyst may, in principle, comprise any catalyst suitable for the synthesis of ammonia. In embodiments, the ammonia synthesis catalyst may, for instance, be selected from the group comprising calcium, potassium, silicon, cesium, bismuth, ruthenium, palladium, molybdenum, rhodium, iridium, platinum, nickel, cobalt, iron, zinc, aluminum, sodium, lithium, magnesium, and copper, or oxides, nitrides, carbides, hydrides or amides thereof. Any catalyst that may (substantially) promote the reaction of dihydrogen and dinitrogen to produce ammonia may be referred to as an ammonia synthesis catalyst, and in embodiments, may be used in the reactor.

As the ammonia synthesis catalyst may (at least partially) inform the operational temperature of ammonia synthesis and, thereby, the temperature of the first gas stream, and as the (de)sorption of ammonia to the sorption material may be temperature-dependent, the ammonia synthesis catalyst and the sorption material may be selected to have suitably matching temperature profiles. For instance, in embodiments, the ammonia synthesis catalyst may comprise a iron-based catalyst and the sorption material may comprise manganese chloride.

Such a combination of catalyst and sorption material may provide the benefit of long-term stable operation. In further embodiments, for example, the ammonia synthesis catalyst may comprise an iron-based catalyst and the sorption material may comprise CaCl:.

In embodiments, the system, especially the feed supply, may comprise a compressor. Especially, the compressor may be configured to compress the feed stream to a pressure in the range of 50-300 bar. Typically, higher pressure shifts the equilibrium of the chemical reactions (in the Haber-Bosch process) in the direction of ammonia production.

Therefore, in embodiments, the compressor may be configured to pressurize the feed stream to a pressure of at least 50 bar, such as at least 100 bar, especially at least 200 bar.

Additionally, in embodiments, the system may comprise a recycle compressor.

Especially, the recycle compressor may compress the recycle stream to a pressure of at least 50 bar, such as at least 100 bar, especially at least 200 bar. This may be particularly advantageous in providing the (pressurized) recycle stream (comprising dinitrogen and dihydrogen) to the reactor, and/or for combining the recycle stream with a fresh feed stream.

Further, in embodiments, the system, especially the ammonia recovery system, may comprise a control system. Especially, the control system may (be configured to) control the one or more temperature control elements.

In another aspect, the invention may provide a separation method for recovering ammonia from a first gas stream using a sorption system. Especially, the sorption system may comprise a plurality of functional units, wherein each functional unit may comprise a first sorption bed and a second sorption bed. Further, in embodiments, the first sorption bed and the second sorption bed may comprise a sorption material suitable for the sorption of ammonia.

The separation method may, in embodiments, comprise simultaneously operating a first proper subset of the functional units in a desorption mode and operating a second proper subset of the functional units in a sorption mode. Especially, the separation method may comprise passing the first gas stream through a first functional unit of the first proper subset of the functional units to provide an ammonia enriched first gas stream. Additionally, in embodiments, the separation method may comprise separating the ammonia enriched first gas stream into a recycle stream and an ammonia product stream. Further, the separation method may comprise passing the recycle stream through a second functional unit of the second subset to provide a purified recycle stream. Further, in embodiments, the separation method may comprise controlling a sorption temperature of at least part of a sorption flow path between the first sorption bed and the second sorption bed of the second functional unit. Especially, the separation method may comprise operating each functional unit alternatingly in the sorption mode and in the desorption mode.

In specific embodiments, the invention may provide a separation method for recovering ammonia from a first gas stream using a sorption system, wherein the sorption system may comprise a plurality of functional units, wherein each functional unit may comprise a first sorption bed and a second sorption bed, wherein the first sorption bed and the second sorption bed comprise a sorption material suitable for the sorption of ammonia, wherein the separation method comprises simultaneously operating a first proper subset of the functional units in a desorption mode and operating a second proper subset of the functional units in a sorption mode, wherein the separation method comprises passing the first gas stream through the first proper subset of the functional units to provide an ammonia enriched first gas stream, wherein the separation method comprises separating the ammonia enriched first gas stream into a recycle stream and an ammonia product stream, wherein the separation method comprises passing the recycle stream through a second functional unit of the second subset to provide a purified recycle stream, and controlling a sorption temperature of at least part of a sorption flow path between the first sorption bed and the second sorption bed of the second functional unit, wherein the separation method comprises operating each functional unit alternatingly in the sorption mode and in the desorption mode.

In embodiments, the separation method may comprise simultaneously operating a first proper subset of the functional units in a desorption mode and operating a second proper subset of the functional units in a sorption mode. The functional units may, in embodiments, be operated both in a sorption and a desorption mode (alternatingly). Operating the functional units in the desorption mode may provide the advantage of regenerating the sorption units comprised by the functional units, thereby making them suitable for further sorption. Hence, operating the first proper subset of functional units in the sorption mode and the second proper subset of the functional units in the desorption mode, and then operating them vice versa, may provide the advantage of regenerating a proper subset of functional units even as a proper subset of functional units is being loaded. Here the term “loaded” may refer to the saturation of the sorption material (with ammonia).

Further, in embodiments, the separation method may comprise passing the first gas stream through the first proper subset of the functional units to provide an ammonia enriched first gas stream. The functional units operated in the desorption mode may essentially release gaseous ammonia from the sorption material into the stream flowed over the sorption beds. Hence, the first gas stream (comprising ammonia) may be further enriched by providing additional ammonia from the sorption material (comprised by the functional units). In embodiments, the separation method may comprise enriching the first gas stream, such that the enriched first gas stream may essentially have more ammonia than the (non-enriched) first gas stream, such as at least 5% more ammonia content, especially at least 10% more ammonia content, such as at least 15% more ammonia content.

Additionally, the separation method may comprise separating the ammonia enriched first gas stream into a recycle stream and an ammonia product stream. Especially, the separation method may comprise providing the ammonia recovered by the recovery unit as the ammonia product stream. Additionally, the separation method may comprise providing a recycle stream (comprising unreacted gases such as dihydrogen, dinitrogen, ammonia, and trace amounts of other compounds) back to the sorption system. This may provide the advantage of reusing the unreacted products. Especially, the separation method may comprise providing the ammonia product stream to the outlet and providing the recycle stream to the functional unit(s) operated in the sorption mode (in the sorption system). These functional units when operated in the desorption mode may (at a later stage) enrich the first gas stream.

Further, in embodiments, the separation method may comprise passing the recycle stream through a second functional unit of the second subset to provide a purified recycle stream. Especially, the separation method may comprise controlling a sorption temperature of at least part of a sorption flow path between the first sorption bed and the second sorption bed of the second functional unit. The recycle stream may comprise ammonia that has not been separated by the recovery unit. Hence, in embodiments, the separation method may comprise separating this ammonia from the recycle stream by means of the functional unit operated in the sorption mode.

Especially, the separation method may comprise operating each functional unit alternatingly in the sorption mode and in the desorption mode. Here, operating the functional units alternatingly refers to operating the functional units first in the sorption mode and subsequently in the desorption mode. Hence, this may provide the advantage of alternatively loading and regenerating the functional units.

The temperature at which ammonia may be sorbed from the recycling stream may be dependent on the type of sorption material used. Hence, the sorption temperature may be selected from the range of < 40 °C, such as from the range of < 30 °C, especially from the range of <20 °C.

Further, the separation method may comprise controlling a desorption temperature of at least part of a desorption flow path between the first sorption bed and the second sorption bed of the first functional unit. Especially, the desorption temperature may be selected from the range of 200-500 °C. Especially, the first gas stream may be flowed through a functional unit operated in the desorption mode. Similar to the sorption temperature, the sorption material may also comprise a desorption temperature beyond which the sorption material may desorb ammonia. Especially, the first gas stream may (already) be provided at the reactor outlet at a high temperature. However, the temperature of the first gas stream may decrease on flowing past the first sorption bed. Hence, in embodiments, the desorption temperature may be controlled in the range 200-500 °C, such as especially in the range 250- 450 °C, such as especially in the range 300-400 °C. The desorption temperature may be controlled by providing heated gas over the sorption material. In embodiments, the first gas stream may be heated before it is flowed through the second sorption bed (in the desorption flow path). Therefore, in embodiments, the temperature control element may heat the first gas stream at one or more locations downstream of the sorption bed (and upstream of the subsequent sorption bed) along the desorption flow path. Hence, in embodiments, the temperature control element may comprise one or more heat exchangers. Especially, these heat exchangers (comprised by the temperature control element) may be configured to heat the first gas stream. Especially, the first gas stream may be heated by heating the first sorption bed that the first gas stream contacts (or is flowed through). Further, in embodiments, the first gas stream may also be heated along the flow path between the reactor and the ammonia recovery system.

Analogous to sorption, desorption of gas decreases the temperature of the sorption material and consequently, the gas flowed over the sorption material. Hence, heating the first gas stream after it is flowed through a first sorption bed may facilitate desorbing ammonia from a second sorption bed arranged downstream from the first sorption bed along a desorption flow path.

In embodiments, the separation method may comprise separating the ammonia enriched first gas stream into the recycle stream and the ammonia product stream by condensation of ammonia. In embodiments, the separation method may comprise separating ammonia from the first gas stream by means of condensation. Especially, the separation method may comprise separating ammonia in a pressurized vessel, pressurized to a pressure selected from the range of a range of at least 1 bar, such as at least 5 bar, especially at least 10 bar.

Note that the pressure at which ammonia may be condensed is dependent (also) on the temperature in the pressurized vessel. It is apparent to the skilled person that the condensation pressure of a gas may depend on the temperature. Hence, ammonia may be separated out from the pressurized vessel at a lower pressure by lowering the temperature of the (enriched) first gas stream. Hence, in embodiments, the pressure within the pressurized vessel may be selected in dependence of the temperature within the pressurized vessel.

Further, for large-capacity ammonia production, refrigerated ammonia storage may be applied. That is, in embodiments, a further separation system, arranged downstream of the separation unit, with a refrigeration unit may be used. Hence, in embodiments, the separation unit may be configured to provide the ammonia product stream to a refrigeration unit.

In a further aspect, the invention may provide a synthesis method for ammonia synthesis. Especially, the synthesis method may comprise exposing a feed stream to an ammonia synthesis catalyst to provide a first gas stream, wherein the feed stream may comprise dihydrogen and dinitrogen. Further, in embodiments, the synthesis method may comprise separating the first gas stream into an ammonia product stream and a recycle stream according to the separation method of the invention. Yet further, the synthesis method may comprise combining a fresh feed stream and the recycle stream to provide the feed stream.

In embodiments, the synthesis method may comprise exposing a feed stream (comprising dinitrogen and dihydrogen) to an ammonia synthesis catalyst to provide a first gas stream. Especially, the first gas stream may comprise ammonia (produced from the reaction of dinitrogen and dihydrogen), unreacted dinitrogen and unreacted dihydrogen. Further, the synthesis method may comprise providing the first gas stream to the sorption system, wherein the first gas stream may be enriched (by the desorption of ammonia into the first gas stream).

In embodiments, the synthesis method may comprise providing the enriched first gas stream to the recovery unit. Especially, the synthesis method may comprise separating the first gas stream into the ammonia product stream and the recycle stream. The recycle stream comprising ammonia may, in embodiments, be provided back to the sorption system, wherein the ammonia from the recycle stream may be sorbed by the sorption material (comprised by the functional unit). Yet further, the synthesis method may comprise providing the recycle stream (after the sorption of ammonia) back to the feed stream or the reactor. Hence, the synthesis method may provide an ammonia synthesis loop for the continuous production of ammonia.

In embodiments, the synthesis method may comprise compressing the feed stream to a pressure in the range of 50-300 bar. In embodiments, the synthesis method may comprise providing dinitrogen and dihydrogen at a pressure higher than 50 bar, such as especially higher than 100 bar, especially higher than 200 bar. The synthesis method may, in embodiments, comprise controlling a feed temperature of the feed stream in the range of 100- 300 °C (right) before the feed stream is provided to the reactor. The reaction of dihydrogen and dinitrogen according to the Haber-Bosch process may be carried out typically in the temperature range of 250-600 °C. Hence, in embodiments, the synthesis method may comprise heating the feed stream to a temperature in the range of 200-600 °C, such as in the range of 250-500 °C, especially in the range of 300-450 °C, such as in the range of 350-400 °C.

The term “downstream” may herein be defined in the context of a flow path. A first element configured “downstream” of a second element 1s configured further along the flow path than the second element. The term “upstream” may herein be defined in the context of a flow path. A first element configured “upstream” of a second element may be configured before the second element along a flow path.

The term “controlling” and similar terms especially refer at least to determining the behavior or supervising the running of an element. Hence, herein “controlling” and similar terms may e.g. refer to imposing behavior to the element (determining the behavior or supervising the running of an element), etc., such as e.g. measuring, displaying, actuating, opening, shifting, changing temperature, etc. Beyond that, the term “controlling” and similar terms may additionally include monitoring. Hence, the term “controlling” and similar terms may include imposing behavior on an element and also imposing behavior on an element and monitoring the element. The controlling of the element can be done with a control system, which may also be indicated as “controller”. The control system and the element may thus at least temporarily, or permanently, functionally be coupled. The element may comprise the control system. In embodiments, the control system and element may not be physically coupled.

The system, or apparatus, or device may execute an action in a “mode” or “operation mode” or “mode of operation” or “operational mode”. The term “operational mode may also be indicated as “controlling mode”. Likewise, in a method an action or stage, or step may be executed in a “mode” or “operation mode” or “mode of operation” or “operational mode”. This does not exclude that the system, or apparatus, or device may also be adapted for providing another controlling mode, or a plurality of other controlling modes. Likewise, this may not exclude that before executing the mode and/or after executing the mode one or more other modes may be executed. However, in embodiments a control system may be available, that is adapted to provide at least the controlling mode. Would other modes be available, the choice of such modes may especially be executed via a user interface, though other options, like executing a mode in dependence of a sensor signal or a (time) scheme, may also be possible. The operation mode may in embodiments also refer to a system, or apparatus, or device, that can only operate in a single operation mode (i.e. “on”, without further tunability).

Hence, in embodiments, the control system may control in dependence of one or more of an input signal of a user interface, a sensor signal (of a sensor), and a timer. The term “timer” may refer to a clock and/or a predetermined time scheme.

The embodiments described herein are not limited to a single aspect of the invention. For example, an embodiment describing the separation method (or the synthesis method) may, for example, further relate to the ammonia separation system (or the system), especially to an operational mode of the system, or especially to the control system. Similarly, an embodiment of the system describing an operation of the system may further relate to embodiments of the method. In particular, an embodiment of the method describing an operation (of the system) may indicate that the system may, in embodiments, be configured for and/or be suitable for the operation. Similarly, an embodiment of the system describing actions of (a stage in) an operational mode may indicate that the method may, in embodiments, comprise those actions.

In particular, in embodiments, the ammonia separation system may (be configured to) execute the separation method of the invention. Similarly, the separation method may comprise using the ammonia separation system of the invention.

In further embodiments, the system may (be configured to) execute the synthesis method of the invention. Similarly, the synthesis method may comprise using the system of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which: Fig. 1 schematically depicts an embodiment of the ammonia separation system. Fig. 2 schematically depicts an embodiment of the system. The schematic drawings are not necessarily on scale.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Fig. 1 schematically depicts an embodiment of the ammonia separation system 1000. The ammonia separation system 1000 may be configured for separating ammonia from a first gas stream 120, wherein the ammonia separation system 1000 may comprise a recovery unit 200 and a sorption system 400. Especially, the sorption system 400 may comprise an inlet 410, an outlet 420, and a plurality of functional units 450. Further, the inlet 410 may be configured to receive the first gas stream 120. Yet further, each functional unit 450 may comprise a first sorption bed 510, a second sorption bed 520, and a temperature control element 430. Furthermore, the first sorption bed 510 and the second sorption bed 520 may comprise a sorption material 455 suitable for the sorption of ammonia, and wherein each functional unit 450 may be operable in a desorption mode and in a sorption mode. Especially, in the desorption mode the functional unit 450 may be configured to provide a desorption flow path for the first gas stream 120 from the inlet 410 to the recovery unit 200 via the first sorption bed 510 and the second sorption bed 520, and in the sorption mode the functional unit 450 may be configured to provide a sorption flow path for the recycle stream 210 from the recovery unit 200 to the outlet 420 via the first sorption bed 510 and the second sorption bed 520. Further, in embodiments, the temperature control element 430 may be configured to control a sorption temperature of at least part of the sorption flow path between the first sorption bed 510 and the second sorption bed 520. Especially, during operation (1) a first (proper) subset 451 of the functional units 450 may be operated in the desorption mode and (ii) a second (proper) subset

452 of the functional units 450 may be operated in the sorption mode. Additionally, the recovery unit 200 may be configured to separate the first gas stream 120 into a recycle stream 210 and an ammonia product stream 220. Particularly, the recovery unit 200 may be configured to provide the recycle stream 210 to the sorption system 400. Further, the recovery unit 200 may be configured to provide the ammonia product stream 220 to a second outlet 230.

In embodiments, the sorption system 400 may comprise a first functional unit 456 and a second functional unit 457. Especially, in a first operational mode, the first functional unit 456 may be operated in the sorption mode and the second functional unit 457 may be operated simultaneously in the desorption mode. Furthermore, in a second operational mode, the first functional unit 456 may be operated in the desorption mode and the second functional unit 457 may be operated in the sorption mode.

The temperature control element 430 may, in embodiments, be configured to cool the recycle stream 210 between the first sorption bed 510 and the second sorption bed 520 along the sorption flow path.

In embodiments, in the desorption mode, the temperature control element 430 may be configured to control a desorption temperature of at least part of the sorption flow path between the first sorption bed 510 and the second sorption bed 520. Further, the desorption temperature may be selected from the range of 200 — 550 °C.

Especially, the recovery unit 200 may comprise a condensation unit configured to separate ammonia from the ammonia enriched first gas stream 120,121 via condensation of the ammonia.

Fig. 1 further schematically depicts an embodiment of the separation method 1 for recovering a first gas stream 120 using a sorption system 400. Further, the sorption system 400 may comprise a plurality of functional units 450, wherein each functional unit 450 may comprise a first sorption bed 510 and a second sorption bed 520. Especially, the first sorption bed 510 and the second sorption bed 520 may comprise a sorption material 455 suitable for the sorption of ammonia. In embodiments, the separation method 1 may comprise simultaneously operating a first (proper) subset 451 of the functional units 450 in a desorption mode and operating a second (proper) subset 452 of the functional units 450 in a sorption mode.

Especially, the separation method 1 may comprise passing the first gas stream 120 through a first functional unit 456 of the first subset to provide an ammonia enriched first gas stream 120.

Yet further, the separation method 1 may comprise separating the ammonia enriched first gas stream 120 into a recycle stream 210 and an ammonia product stream 220. Especially, the separation method 1 may comprise passing the recycle stream 210 through a second functional unit 457 of the second subset to provide a purified recycle stream211. Further, the separation method 1 may comprise controlling a sorption temperature of at least part of a sorption flow path between the first sorption bed 510 and the second sorption bed 520 of the second functional unit 457. Subsequently, the separation method 1 may (also) comprise operating each functional unit 450 alternatingly in the sorption mode and in the desorption mode. Furthermore, the separation method 1 may comprise selecting the sorption temperature, wherein the sorption temperature may be selected from the range of <40 °C.

In embodiments, the separation method 1 may comprise controlling a desorption temperature of at least part of a desorption flow path between the first sorption bed 510 and the second sorption bed 520 of the first functional unit 456. Especially, the desorption temperature may be selected from the range of 200 — 500 °C. Further, in embodiments, the method may comprise separating the ammonia enriched first gas stream 120 into the recycle stream 210 and the ammonia product stream 220 by condensation of ammonia.

Fig. 2 schematically depicts an embodiment of a system 10 comprising the ammonia separation system 1000. Especially, the system may comprise a feed supply 100 further comprising a dinitrogen supply 150 and a dihydrogen supply 140. Hence, in embodiments, the feed supply 100 may be configured to provide a feed stream 110 to the reactor 600, wherein the feed stream 110 may comprise dihydrogen and dinitrogen. In embodiments, the feed supply 100 may be configured to provide a feed stream 110 to the reactor 600. Here, the feed stream 110 may comprise a combination of a fresh feed stream 115 and the recycle stream 210. In embodiments, the system 10 may comprise a compressor 800. Especially, the compressor 800 may be configured to compress the feed stream 110 to a pressure in the range of 50-300 bar. Further, in embodiments, the system 10 may comprise a second temperature control element 130, which may be configured to heat the feed stream to a temperature in the range of 100-300 °C. Especially, the reactor 600 may be configured to receive the feed stream 110, and to provide the first gas stream 120 to the inlet 410. Further, the outlet 420 may be configured to provide the recycle stream 210 to the feed supply 100 and/or the reactor 600.

Further, in embodiments, the system 10 may comprise an air supply 710. Especially, the air supply may be provided using an air blower 720. Especially, an air stream 721 may be provided by the air blower 720 to the reactor 600. Further, a (used) air stream 602 may be provided to the air chimney exit 730. Yet further, impure gases separated from the ammonia separation system 1000 may be separated and provided to a gas chimney 740.

In embodiments, the system 10 may comprise a control system 300. The control system 300 may, for instance, be configured to control the sorption system 400. Further, in embodiments, the sorption system 400 may comprise a sensor element 330. Especially, the sensor element 330 may comprise a temperature sensor configured to determine a temperature of the (purified) recycle stream 211 downstream of the second subset 452 of functional units 450, and to provide a temperature-related signal to the control system 300. In embodiments, the control system 300 may be configured to switch the operational modes of the first subset 451 of functional units 450 and the second subset 452 of functional units 450 when the purified recycle stream 211 has a temperature selected from the range of 50 — 120 °C.

In the depicted embodiment, the sorption system 400 comprises a plurality of sensor elements 330. In particular, the sorption system 400 comprises a sensor element 330 arranged downstream of the second subset 452 of functional units 450, near the outlet 420.

Further, the sorption system 400 comprises sensor elements 330 arranged between the first sorption element 540 and the second sorption element 550 of the plurality of functional units 450. Especially, for each functional unit 450, a respective sensor element 330 may be arranged between the first sorption bed 510 and the second sorption bed 520 along a flow path, such as along a sorption flow path, and/or such as along a desorption flow path.

In embodiments, the ammonia separation system may be used for recovering a first gas stream 120 using a sorption system 400. Further, the sorption system 400 may comprise a plurality of functional units 450, wherein each functional unit 450 may comprise a first sorption bed 510 and a second sorption bed 520. Especially, the first sorption bed 510 and the second sorption bed 520 may comprise a sorption material 455 suitable for the sorption of ammonia.

In embodiments, the separation method 1 may comprise simultaneously operating a first (proper) subset 451 of the functional units 450 in a desorption mode and operating a second (proper) subset 452 of the functional units 450 in a sorption mode.

Especially, the separation method | may comprise passing the first gas stream 120 through a first functional unit 456 of the first subset to provide an ammonia enriched first gas stream 120.

Yet further, the separation method 1 may comprise separating the ammonia enriched first gas stream 120 into a recycle stream 210 and an ammonia product stream 220. Especially, the separation method 1 may comprise passing the recycle stream 210 through a second functional unit 457 of the second subset to provide a purified recycle stream211. Further, the separation method 1 may comprise controlling a sorption temperature of at least part of a sorption flow path between the first sorption bed 510 and the second sorption bed 520 of the second functional unit 457. The separation method 1 may (also) comprise operating each functional unit 450 alternatingly in the sorption mode and in the desorption mode. Furthermore, the separation method 1 may comprise selecting the sorption temperature, especially wherein the sorption temperature may be selected from the range of <40 °C.

In the depicted embodiment, each functional unit 450 may comprise a first sorption element 540 and a second sorption element 550, wherein the first sorption element 540 may comprise the respective first sorption bed 510, and wherein the second sorption element 550 may comprise the respective second sorption bed 520. Additionally, the temperature control element 430 may be configured to control the sorption temperature of at least part of the sorption flow path between the first sorption element 540 and the second sorption element 550. Especially, the sorption temperature may be selected from the range of <40 °C.

Fig. 2 further schematically depicts an embodiment of the synthesis method 2 for ammonia synthesis. In embodiments, the feed supply may comprise a dihydrogen supply 140 and a dinitrogen supply 150. Further, the feed supply may be configured to provide a feed stream 110. Especially, the synthesis method 2 may comprise exposing a feed stream 110 to an ammonia synthesis catalyst to provide a first gas stream 120, wherein the feed stream 110 comprises dihydrogen and dinitrogen. Further, the synthesis method 2 may comprise separating the first gas stream 120 into an ammonia product stream 220 and a recycle stream 210 using the separation method 1. Especially, the synthesis method 2 may comprise combining a fresh feed stream 115 and the recycle stream 210 to provide the feed stream 110. In embodiments, the synthesis method 2 may comprise compressing the feed stream 110 to a pressure in the range of 50-300 bar. Further, the synthesis method 2 may comprise controlling a feed temperature of the feed stream 110 in the range of 100-300 °C. Especially, the feed stream 110 may be heated by means of a second temperature control element 130. Yet further, in embodiments, the method may comprise controlling the temperature control element 430 (comprised by the ammonia separation system 1000) and the second temperature control element 130 comprised by the system 10.

The term “plurality” refers to two or more. Furthermore, the terms “a plurality of” and “a number of” may be used interchangeably.

The terms “substantially” or “essentially” herein, and similar terms, will be understood by the person skilled in the art. The terms “substantially” or “essentially” may also include embodiments with “entirely”, “completely”, “all”, etc. Hence, in embodiments the adjective substantially or essentially may also be removed. Where applicable, the term “substantially” or the term “essentially” may also relate to 90% or higher, such as 95% or higher, especially 99% or higher, even more especially 99.5% or higher, including 100%.

Moreover, the terms “about” and “approximately” may also relate to 90% or higher, such as 95% or higher, especially 99% or higher, even more especially 99.5% or higher, including 100%. For numerical values it is to be understood that the terms “substantially”, “essentially”, “about”, and “approximately” may also relate to the range of 90% - 110%, such as 95%-105%, especially 99%-101% of the values(s) it refers to.

The term “comprise” also includes embodiments wherein the term “comprises” means “consists of”.

The term “and/or” especially relates to one or more of the items mentioned before and after “and/or”. For instance, a phrase “item 1 and/or item 2” and similar phrases may relate to one or more of item 1 and item 2. The term "comprising" may in an embodiment refer to "consisting of" but may in another embodiment also refer to "containing at least the defined species and optionally one or more other species”.

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

The devices, apparatus, or systems may herein amongst others be described during operation. As will be clear to the person skilled in the art, the invention is not limited to methods of operation, or devices, apparatus, or systems in operation.

The term “further embodiment” and similar terms may refer to an embodiment comprising the features of the previously discussed embodiment but may also refer to an alternative embodiment.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim.

Use of the verb "to comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, “include”, “including”, “contain”, “containing” and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.

The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In a device claim, or an apparatus claim, or a system claim, enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

The invention also provides a control system that may control the device, apparatus, or system, or that may execute the herein described method or process. Yet further, the invention also provides a computer program product, when running on a computer which is functionally coupled to or comprised by the device, apparatus, or system, controls one or more controllable elements of such device, apparatus, or system.

The invention further applies to a device, apparatus, or system comprising one or more of the characterizing features described in the description and/or shown in the attached drawings. The invention further pertains to a method or process comprising one or more of the characterizing features described in the description and/or shown in the attached drawings.

Moreover, if a method or an embodiment of the method is described being executed in a device, apparatus, or system, it will be understood that the device, apparatus, or system is suitable for or configured for (executing) the method or the embodiment of the method, respectively.

The various aspects discussed in this patent can be combined in order to provide additional advantages. Further, the person skilled in the art will understand that embodiments can be combined, and that also more than two embodiments can be combined. Furthermore, some of the features can form the basis for one or more divisional applications.

Claims

Conclusions

1. An ammonia separation system (1000) for separating ammonia from a first gas stream (120), the ammonia separation system (1000) comprising a recovery unit (200) and a sorption system (400), the sorption system (400) having an inlet (410) , an outlet (420), and a plurality of functional units (450), wherein: - the inlet (410) is configured to receive the first gas flow (120); - each functional unit (450) comprises a first sorption bed (510), a second sorption bed (520), and a temperature control element (430), wherein the first sorption bed (510) and the second sorption bed (520) contain a sorption material (455) suitable for the sorption of ammonia, and wherein each functional unit (450) is operable in a desorption mode and in a sorption mode, where: - in the desorption mode the functional unit (450) is configured to provide a desorption flow path from the inlet through the first sorption bed (510 ) and the second sorption bed (520) to the recovery unit (200); - in sorption mode the functional unit (450) is configured to provide a sorption flow path from the recovery unit (200) through the first sorption bed (510) and the second sorption bed (520) to the outlet (420), wherein the temperature control element (430) configured to control a sorption temperature of at least a portion of the sorption flow path between the first sorption bed (510) and the second sorption bed (520); - during use (i) a first subset (451) of the functional units (450) is operated in the desorption mode and (11) a second subset (452) of the functional units (450) is operated in the sorption mode; - the recovery unit (200) is configured to separate the first gas stream (120) into a recycle stream (210) and an ammonia product stream (220), and the recovery unit (200) is configured to supply the recycle stream (210) to the sorption system (400) ), and wherein the recovery unit (200) is configured to provide the ammonia product stream (220) to a second outlet (230).

The ammonia separation system (1000) according to claim 1, wherein: - the sorption system (400) comprises a first functional unit (456) and a second functional unit (457); - in a first operational mode the first functional unit (456) is operated in the sorption mode and the second functional unit (457) is operated in the desorption mode; - in a second operational mode the first functional unit (456) is operated in the desorption mode and the second functional unit (457) is operated in the sorption mode.

The ammonia separation system (1000) according to any one of the preceding claims, wherein the temperature control element (430) is configured to cool the recycle stream (210) along the sorbent flow path between the first sorbent bed (510) and the second sorbent bed (520).

The ammonia separation system (1000) according to any one of the preceding claims, wherein each functional unit (450) comprises a first sorption element (540) and a second sorption element (550), the first sorption element (540) being the first sorption bed (510), and wherein the second sorption element (550) includes the second sorption bed (520), and wherein the temperature control element (430) is configured to control the sorption temperature of at least a portion of the sorption flow path between the first sorption element (540) and the second sorption element (550).

The ammonia separation system (1000) according to any of the preceding claims, wherein the sorption temperature is selected from the range of < 40 °C.

The ammonia separation system (1000) according to any one of the preceding claims, wherein the recovery unit (200) includes a condensation unit configured to separate ammonia from the first gas stream (120) via condensation.

The ammonia separation system (1000) according to any one of the preceding claims, wherein the ammonia separation system (1000) comprises a control system (300), wherein the sorption system (400) comprises a sensor element (330), wherein the sensor element (33) comprises a temperature sensor that configured to determine the temperature of the recycle stream (210) downstream of the second subset (452) of functional units (450), and to provide a temperature-related signal to the control system (300), wherein the control system (300) configured to switch the operational modes of the first subset (451) of functional units (450) and the second subset (452) of functional units (450) when the recycle stream (210) reaches a temperature selected from the range 50 - 120 °C has.

A system (10) comprising the ammonia separation system (1000) according to any preceding claim, wherein the system (10) comprises a reactor (600) and a feed supply (100), the reactor (600) comprising an ammonia synthesis catalyst, and wherein: - the power supply (100) is configured to provide a feed stream (110) to the reactor (600), the feed stream (110) comprising dihydrogen and dinitrogen; - the outlet (420) is configured to provide the recycle stream (210) to the power supply (100); and - the reactor (600) is configured to receive the feed stream (110) and to provide the first gas stream (120).

The system (10) of claim 8, wherein the system (10) includes a compressor (800); wherein the compressor (800) is configured to compress the feed stream (110) to a pressure in the range of 50-300 bar.

10. A separation method (1) for separating ammonia from a first gas stream (120) using a sorption system (400), wherein the sorption system (400) comprises a plurality of functional units (450), each functional unit (450) ) comprises a first sorbent bed (510) and a second sorbent bed (520), wherein the first sorbent bed (510) and the second sorbent bed (520) comprise a sorbent material (455) suitable for the sorption of ammonia, wherein the separation method (1) comprises : - operating a first subset (451) of the functional units (450) in a desorption mode and simultaneously operating a second subset (452) of the functional units (450) in a desorption mode; - passing the first gas flow (120) through a first functional unit (456) of the first subset; - separating the first gas stream (120) into a recycle stream (210) and an ammonia product stream (220); - passing the recycle stream (210) through a second functional unit (457) of the second subset, and controlling a sorption temperature of at least part of a sorption flow path between the first sorption bed (510) and the second sorption bed (520) of the second functional unit (457); - alternately operating each functional unit (450) in the sorption mode and in the desorption mode.

The separation method (1) according to claim 10, wherein the sorption temperature is selected from the range of < 40 °C.

The separation method (1) according to any of the preceding claims 10-11, wherein the separation method (1) comprises separating the first gas stream (120) via condensation of ammonia in the recycle stream (210) and the ammonia product stream (220).

A synthesis method (2) for ammonia synthesis, the synthesis method comprising: - exposing a feed stream (110) to an ammonia synthesis catalyst to provide a first gas stream (120), the feed stream (110) comprising dihydrogen and dinitrogen; - separating the first gas stream (120) into an ammonia product stream (220) and a recycle stream (210) according to the recovery method (1) of any of the preceding claims 9-11; - combining a fresh feed stream (115) and the recycle stream (210) to provide the feed stream (110).

The synthesis method (2) according to claim 13, wherein the synthesis method (2) comprises compressing the feed stream (110) to a pressure in the range of 50-300 bar.

The synthesis method (2) according to any of the preceding claims 13-14, wherein the synthesis method (2) comprises heating the feed stream to a temperature in the range of 200-700°C.