Process for producing a synthesis gas product containing hydrogen

Abstract

A process (100, 200) for producing a synthesis gas product comprising hydrogen from an endothermic decomposition reaction of an ammonia feed stream, said process comprising the following steps: venting an effluent gas stream produced by a heating step (109, 209) and / or by a primary catalytic endothermic conversion (103, 203); recovering heat from said effluent gas stream in a heat recovery step (111, 211); redirecting the recovered heat (113, 114, 213, 214) to at least one secondary reactor, the secondary reactor comprising a gas reaction section in which a secondary catalytic endothermic conversion of the ammonia feed stream takes place (104, 204); and transferring the redirected heat to the secondary catalytic endothermic conversion in a heat transfer step through a thermally conductive layer at least partially bounding the gas reaction section.

Description

[Technical Field]

[0001] The field of the invention is that of apparatus for producing a synthesis gas product. The invention particularly relates to apparatus for producing a synthesis gas product comprising hydrogen by endothermic reaction of an ammonia feed stream. The invention also relates to a process for producing a synthesis gas product comprising hydrogen. [Background technology]

[0002] The endothermic reaction of an ammonia feed stream to produce a synthesis gas product containing hydrogen can be carried out in a catalytic unit at high temperatures, generally between 400°C and 800°C. Such units typically include a metal shell, a catalyst, and an external heat source. To achieve the lowest possible CO2 footprint for the decomposition process, the external heat source is provided solely by the combustion of an ammonia fuel stream in a furnace. Heat is transferred to the catalyst to promote the decomposition reaction, which requires a large amount of heat and energy to promote the decomposition reaction. If the catalyst temperature is too low to promote the decomposition reaction, the ammonia conversion rate is significantly reduced. The disadvantages of such a process are that it requires a large amount of external energy and the conversion rate of the ammonia feed stream can be low. Summary of the Invention [Problem to be solved by the invention]

[0003] The present invention proposes a process for producing a synthesis gas product containing hydrogen from the endothermic decomposition reaction of an ammonia feed stream, with significantly reduced external energy requirements and significantly improved conversion of the decomposition reaction. [Means for solving the problem]

[0004] The present invention proposes a process for producing a synthesis gas product comprising hydrogen from an endothermic decomposition reaction of an ammonia feed stream, said process comprising the steps of: providing an ammonia feed stream; heating the primary reactor in a heating step; converting the partially converted ammonia stream in a heated primary reactor by primary catalytic endothermic conversion of said partially converted ammonia stream; venting an effluent gas stream produced by the heating step and / or by the primary catalytic endothermic conversion; recovering heat from the effluent gas stream in a heat recovery step; redirecting the heat recovered in the heat redirection step to at least one secondary reactor, the secondary reactor comprising a gas reaction section in which a secondary catalytic endothermic conversion of the ammonia feed stream occurs; transferring the redirected heat to a secondary catalytic endothermic conversion through a thermally conductive layer at least partially defining the gas reaction region in a heat transfer step. Includes:

[0005] In this disclosure, the primary catalytic endothermic conversion may also be referred to as the primary catalytic conversion, and the secondary catalytic endothermic conversion may also be referred to as the secondary catalytic conversion.

[0006] In one embodiment of the invention, the primary catalytic endothermic conversion is the primary cracking reaction of the partially converted feed stream.

[0007] The synthesis gas products include hydrogen and nitrogen.

[0008] In one embodiment of the present invention, the primary and secondary catalytic conversions occur sequentially in the direction of flow of the ammonia feed stream.

[0009] In one aspect of the invention, the secondary catalytic conversion is upstream of the main catalytic conversion in the flow direction of the ammonia feed stream, the ammonia feed stream being converted by the secondary catalytic endothermic conversion to a partially converted ammonia stream, and the partially converted ammonia stream being converted by the main catalytic endothermic conversion to a synthesis gas product.

[0010] In one aspect of the invention, the partially converted ammonia stream is a pre-cracked ammonia feed stream.

[0011] In one aspect of the invention, the secondary catalytic conversion is a pre-cracking reaction of an ammonia feed stream. A pre-cracking reaction is a reaction in which a feed, here an ammonia feed stream, is pre-cracking upstream of a cracking reaction, here a main cracking reaction.

[0012] In one aspect of the invention, the secondary catalyst conversion is carried out at a conversion rate similar to that of the main catalyst, and preferably the secondary catalyst conversion rate is lower than the main catalyst conversion rate.

[0013] In one embodiment of the invention, the secondary catalyst conversion is comprised between 15% and 90%, preferably between 15% and 50%, preferably between 15% and 20%.

[0014] In one aspect of the invention, the secondary catalytic conversion is achieved at a lower temperature than the primary catalytic conversion.

[0015] In one embodiment of the invention, the secondary catalytic conversion is carried out at a temperature comprised between 350° C. and 650° C., preferably at a temperature of about 550° C., and the main catalytic conversion is carried out at a temperature comprised between 600° C. and 900° C., preferably between 700° C. and 800° C., for example at a pressure of about 30 bar A. The lower temperature of the secondary catalytic conversion allows the use of a catalyst different from that of the main catalytic conversion, said catalyst requiring a lower temperature to operate, thus improving the total conversion of the cracking reactions.

[0016] In one embodiment of the invention, the primary catalytic conversion occurs in a primary reactor where a primary catalyst is present, and the secondary catalytic conversion occurs in a secondary reactor where a secondary catalyst is present.

[0017] In another aspect of the invention, the secondary catalyst has a different composition than the primary catalyst.

[0018] In one embodiment of the invention, the primary catalytic conversion and the secondary catalytic conversion are carried out over separate catalyst beds.

[0019] According to one aspect of the invention, the primary catalyst comprises nickel as the catalytically active material, in particular as the catalytically active material on a support, for example an aluminum oxide (Al2O3) support.

[0020] According to one embodiment of the present invention, the primary catalyst comprises 5-20 wt% nickel, preferably about 15 wt% nickel.

[0021] According to one aspect of the invention, the secondary catalyst comprises nickel as the catalytically active material, in particular as the catalytically active material on a support, for example an aluminum oxide (Al2O3) support.

[0022] According to one aspect of the invention, the secondary catalyst comprises a noble metal as catalytically active material, such as more than 20 wt% to more than 45 wt% nickel, preferably more than 35 wt% nickel, and / or ruthenium, preferably 1.5 wt% ruthenium.

[0023] In one aspect of the invention, the process includes a preheating step of the partially converted ammonia stream, and both the pre-decomposition and preheating steps occur in a secondary reactor.

[0024] According to one aspect of the invention, the preheating step is performed entirely by a secondary reactor.

[0025] The present invention proposes a process for producing a synthesis gas product comprising hydrogen from an endothermic decomposition reaction of an ammonia feed stream, said process comprising the following steps: providing an ammonia feed stream; heating the primary reactor in a heating step; converting an ammonia feed stream in a heated primary reactor by primary catalytic endothermic conversion of said ammonia feed stream; venting an effluent gas stream produced by the heating step and / or by the primary catalytic endothermic conversion; recovering heat from the effluent gas stream in a heat recovery step; redirecting the heat recovered in the heat redirection step to at least one secondary reactor, the secondary reactor comprising a gas reaction section in which a secondary catalytic endothermic conversion of the ammonia feed stream occurs; transferring the redirected heat to a secondary catalytic endothermic conversion through a thermally conductive layer at least partially defining the gas reaction region in a heat transfer step. Includes:

[0026] The synthesis gas product includes hydrogen and nitrogen.

[0027] In one embodiment of the present invention, the ammonia feed stream is split into at least two split ammonia feed streams, one of which is provided to the primary reactor and the other split ammonia feed stream is provided to the secondary reactor.

[0028] In one aspect of the invention, the secondary catalytic conversion is achieved simultaneously with the primary catalytic conversion.

[0029] In one embodiment of the invention, the primary catalytic conversion is carried out at the same conversion rate as the secondary catalytic conversion.

[0030] In one aspect of the invention, the primary catalytic conversion and the secondary catalytic conversion are achieved at the same temperature.

[0031] In another aspect of the invention, the secondary catalytic conversion is achieved at a lower temperature than the primary catalytic conversion.

[0032] In one embodiment of the invention, the secondary catalytic conversion and / or the main catalytic conversion is carried out at a temperature comprised between 500°C and 800°C, preferably between 600°C and 700°C, for example at a pressure below 30 bar A, preferably between 15 bar A and 20 bar A.

[0033] In one embodiment of the invention, the primary catalytic conversion takes place in a primary reactor in which a primary catalyst is present, and the secondary catalytic conversion takes place in a secondary reactor in which a secondary catalyst is present.

[0034] In one aspect of the invention, the secondary catalyst has the same composition as the primary catalyst.

[0035] In another aspect of the invention, the secondary catalyst has a different composition than the primary catalyst.

[0036] In one embodiment of the invention, the primary catalytic conversion and the secondary catalytic conversion are carried out over separate catalyst beds.

[0037] In one embodiment of the present invention, the primary catalyst and / or secondary catalyst comprises nickel as the catalytically active material, for example in the range of 5-20 wt% nickel, preferably about 15 wt% nickel.

[0038] In another embodiment of the invention, the secondary catalyst comprises nickel as catalytically active material, for example more than 20 wt.% to more than 45 wt.% nickel, preferably more than 35 wt.% nickel, and / or a noble metal as catalytically active material, such as ruthenium, preferably 1.5 wt.% ruthenium.

[0039] In one aspect of the present invention, the secondary reactor is a non-adiabatic reactor. In one aspect of the present invention, the secondary reactor is an isothermal reactor. Here, an adiabatic reactor refers to a reactor in which a reaction occurs while no heat exchange occurs between the reaction and the environment outside the reactor. In such an adiabatic reactor, in the case of an endothermic reaction, the temperature decreases from the inlet to the outlet of the reactor. Conversely, a non-adiabatic reactor is a reactor in which heat exchange occurs between the reaction and the environment outside the reactor. In other words, the non-adiabatic reactor is arranged for catalytic endothermic conversion and heat exchange of the ammonia feed stream. In an isothermal reactor, in the case of an endothermic reaction, there is no substantial decrease in temperature from the inlet to the outlet of the reactor.

[0040] In one aspect of the invention, the effluent gas stream comprises a tail gas stream and / or a synthesis gas product.

[0041] In one aspect of the invention, the step of venting the effluent gas stream comprises venting the effluent gas stream into an effluent gas conduit configured to discharge the effluent gas stream, and specifically, the step of recovering heat comprises recovering heat from the exhaust gas stream in the effluent conduit.

[0042] In one aspect of the invention, the heating step includes combusting a fuel gas stream into an exhaust gas stream in a combustion reaction carried out in a firing chamber.

[0043] In one aspect of the invention, the step of venting the effluent gas stream comprises venting the effluent gas stream, particularly into an exhaust gas conduit such as an effluent tunnel. Specifically, the process comprises discharging the exhaust gas stream from the calcination chamber, and the heat recovery step comprises recovering heat from the exhaust gas stream discharged from the calcination chamber, particularly in the exhaust gas conduit. In one aspect of the invention, the combustion reaction takes place outside the primary reactor.

[0044] In one aspect of the invention, the heating step comprises heating the primary reactor with an electric heating device.

[0045] In one aspect of the invention, the step of venting the effluent gas stream comprises venting the synthesis gas product, specifically venting the synthesis gas product in a synthesis gas conduit. Specifically, the process comprises venting the synthesis gas product from the primary reactor, and the heat recovery step comprises recovering heat from the vented synthesis gas product, specifically in the synthesis gas conduit.

[0046] In one aspect of the invention, the heat recovery and redirection steps are performed by convective heat transfer from the effluent gas stream to the secondary reactor.

[0047] In one aspect of the invention, convective heat transfer occurs towards and around the secondary reactor through the fluid motion of the exiting gas stream.

[0048] In one aspect of the invention, the heat transfer step is performed by thermal conduction from the effluent gas through the thermally conductive layer to the gas reaction section.

[0049] In one aspect of the invention, heat from the primary catalytic endothermic conversion is directed to the secondary catalytic conversion by heat exchange between at least a portion of the effluent gas stream and an ammonia feed stream that is converted in a secondary reactor.

[0050] In one aspect of the invention, the heat transfer step occurs through a heat exchanger.

[0051] In one aspect of the invention, the secondary reactor is a secondary reactor that heats the synthesis gas and includes a synthesis gas product recycle section disposed in heat exchange relationship with the gas reaction section, through which at least a portion of the synthesis gas product is circulated.

[0052] According to one aspect of the invention, the syngas product recycle section comprises at least one syngas recycle line.In one aspect of the invention, the heat exchanger is a fluid-fluid heat exchanger.

[0053] In one aspect of the invention, the process includes processing the syngas product, for example purifying the syngas product.

[0054] According to one aspect of the present invention, the ammonia feed stream contains sub-ppm levels of impurities such as sulfur, oil, chlorine, and water, in other words, the purity of the ammonia feed stream is high and does not allow impurities to deposit on the catalyst.

[0055] According to one aspect of the present invention, the secondary reactor is a single-pass reactor, i.e., the ammonia feed stream circulates once through the gas reaction section, thus facilitating the loading of catalyst into the secondary reactor.

[0056] According to one aspect of the invention, the ammonia feed stream circulates unidirectionally within the secondary reactor.

[0057] According to one aspect of the invention, the process includes controlling the rate of fuel gas flow depending on the flow rates of the feed streams, the calculated reaction heat requirement and / or the outlet temperature of the primary reactor.

[0058] According to one aspect of the invention, the flow rate of the fuel gas stream is reduced as the flow rate of the ammonia feed stream is reduced, and the flow rates are thus controlled to obtain the desired reaction temperatures in the primary and secondary endothermic cracking reactions and, therefore, the desired conversion rate of the synthesis gas product.

[0059] According to one aspect of the present invention, the production of by-product streams is reduced during catalytic conversion. Preferably, the production of by-product streams is avoided during catalytic conversion.

[0060] The present invention also relates to an apparatus for producing a synthesis gas product comprising hydrogen by endothermic decomposition of an ammonia feed stream, said apparatus comprising: a primary reactor configured to produce a synthesis gas product comprising hydrogen by primary endothermic catalytic conversion of the partially converted ammonia feedstream; a heating device positioned to provide heat to the primary reactor; an effluent gas conduit positioned to discharge an effluent gas stream from the primary reactor and / or from the heating device; at least one secondary reactor including a gas reaction section, the gas reaction section including a catalyst configured to promote a secondary endothermic catalytic conversion of the ammonia feed stream to a partially converted ammonia feed stream, the gas reaction section being at least partially bounded by a thermally conductive layer positioned in an outlet gas conduit to recover a portion of heat from the outlet gas stream and provide the recovered heat to the catalyst; Includes:

[0061] In one embodiment of the invention, the secondary reactor is located upstream of the primary reactor in the direction of flow of the ammonia feed stream.

[0062] In one aspect of the invention, the apparatus includes a partially converted ammonia feed conduit positioned to discharge the partially converted ammonia feed from the secondary reactor and to feed the discharged partially converted ammonia feed to the primary reactor.

[0063] In one aspect of the invention, the primary reactor includes a primary catalyst configured to promote a primary catalytic conversion, and the catalyst included in the secondary reactor is a secondary catalyst.

[0064] In one embodiment of the invention, the main catalyst is configured to enable main catalytic conversion of the partially converted ammonia feed stream at a temperature comprised between 600°C and 900°C, preferably between 700°C and 800°C, for example at a pressure of about 30 bar A.

[0065] Specifically, the primary catalyst comprises nickel as the catalytically active material, specifically on a support, such as an aluminum oxide (Al2O3) support.

[0066] According to one embodiment of the present invention, the primary catalyst comprises 5-20 wt% nickel, preferably about 15 wt% nickel.

[0067] In one aspect of the invention, the catalyst or secondary catalyst is configured for secondary catalytic conversion of the ammonia feed stream at a temperature comprised between 350°C and 650°C, preferably at a temperature of about 550°C, for example at a pressure of about 30 bar A.

[0068] According to one aspect of the invention, the catalyst or secondary catalyst comprises nickel as the catalytically active material, in particular as the catalytically active material on a support, for example an aluminum oxide (Al2O3) support.

[0069] According to one aspect of the invention, the catalyst or secondary catalyst comprises a noble metal as catalytically active material, such as more than 20 wt. % to more than 45 wt. % nickel, preferably more than 35 wt. % nickel, and / or ruthenium, preferably more than 1.5 wt. % ruthenium.

[0070] The present invention also relates to an apparatus for producing a synthesis gas product comprising hydrogen by endothermic decomposition of an ammonia feed stream, said apparatus comprising: a primary reactor configured to produce a synthesis gas product comprising hydrogen by primary endothermic catalytic conversion of an ammonia feedstream; a heating device positioned to provide heat to the primary reactor; an effluent gas conduit arranged to discharge effluent gas from the primary reactor and / or from the heating device; at least one secondary reactor including a gas reaction section, the gas reaction section including a catalyst configured to promote a secondary catalytic conversion of the ammonia feedstream to a synthesis gas product including hydrogen, the gas reaction section being at least partially bounded by a thermally conductive layer positioned in an outlet gas conduit to recover a portion of heat from the outlet gas stream and provide the recovered heat to the catalyst; Includes:

[0071] In one embodiment of the invention, the secondary reactor is fluidly positioned parallel to the primary reactor in the direction of flow of the ammonia feed stream.

[0072] In one aspect of the invention, the primary reactor includes a primary catalyst configured to promote a primary catalytic conversion, and the catalyst included in the secondary reactor is a secondary catalyst.

[0073] In one embodiment of the invention, the primary catalyst and the secondary catalyst have the same composition.

[0074] In another embodiment of the invention, the primary and secondary catalysts have different compositions.

[0075] According to one aspect of the invention, the primary catalyst and / or secondary catalyst or catalysts comprise nickel as the catalytically active material, specifically as the catalytically active material on a support, such as an aluminum oxide (Al2O3) support. Specifically, the primary catalyst comprises 5-20 wt% nickel, preferably about 15 wt% nickel.

[0076] In one aspect of the invention, the apparatus includes a separator positioned to divide the ammonia feed stream into at least two separate ammonia feed streams.

[0077] In one embodiment of the invention, the secondary reactor is a non-adiabatic reactor.

[0078] In one aspect of the invention, the apparatus includes a feed conduit positioned to deliver an ammonia feedstock to the primary reactor.

[0079] In one aspect of the invention, the gas reaction section is bounded by a thermally conductive layer configured to transfer heat to a secondary catalytic endothermic conversion.

[0080] In one aspect of the invention, the secondary reactor includes a heat exchanger configured to exchange heat between the gas reaction section and the external environment.

[0081] In one aspect of the invention, the heating device includes a firing chamber configured to combust a fuel gas stream into an exhaust gas stream. Specifically, the outlet gas conduit includes an exhaust gas conduit configured to exhaust the exhaust gas from the firing chamber. For example, the exhaust gas conduit includes an outlet tunnel.

[0082] In one aspect of the invention, the thermally conductive layer is positioned to recover a portion of heat from the exhaust gas flow in the exhaust gas conduit, particularly from the exhaust gas flow discharged from the firing chamber.

[0083] In one aspect of the invention, the heating device comprises an electric heating device.

[0084] In one aspect of the invention, the effluent gas conduit comprises a syngas conduit positioned to discharge syngas product from the primary reactor.

[0085] In one aspect of the invention, the thermally conductive layer is positioned to recover a portion of heat from the syngas product stream in the syngas conduit, specifically from the syngas product stream discharged from the primary reactor.

[0086] In one aspect of the invention, the at least one secondary reactor comprises a synthesis gas heated secondary reactor, and the synthesis gas conduit comprises a synthesis gas product circulation section disposed in heat exchange relationship with the gas reaction section, the gas reaction section being delimited from the synthesis gas product circulation section by a thermally conductive layer. In other words, the thermally conductive layer is disposed to exchange heat between the ammonia feed stream and the synthesis gas product from the primary catalytic endothermic conversion. In other words, in this embodiment, the heat exchanger is a fluid / fluid heat exchanger.

[0087] Specifically, the synthesis gas product circulation section includes at least one synthesis gas circulation pipe arranged to circulate the synthesis gas product.

[0088] In one aspect of the invention, the thermally conductive layer comprises a wall of a syngas recycle pipe.

[0089] Specifically, the gas reaction section includes a shell, the shell is filled with a catalyst or a secondary catalyst, and at least one syngas circulation tube extends inside the shell. Preferably, a plurality of syngas circulation tubes extend inside the shell. In other words, the heat exchanger is a tube / shell heat exchanger.

[0090] In one embodiment of the present invention, the at least one secondary reactor comprises a secondary reactor heated by exhaust gas. The gas reaction section comprises at least one feed circulation pipe arranged to circulate and react an ammonia feed stream, the feed circulation pipe being filled with a catalyst or a secondary catalyst and arranged to exchange heat with the exhaust gas discharged from the calcination chamber in the exhaust gas conduit, the feed circulation pipe preferably having a coil shape. In other words, the effluent gas circulates around the feed circulation pipe, and heat is transferred from the effluent gas to the secondary catalytic conversion.

[0091] Specifically, the feed recycle pipe extends through a recycle portion of the exhaust gas conduit, and the exhaust gas conduit is configured to distribute the exhaust gas flow around the feed recycle pipe.

[0092] Specifically, the raw material circulation pipe has a diameter of 2 to 4 inches (0.0508 m to 0.1016 m), preferably about 3 inches (0.0762 m).

[0093] Specifically, the fuel circulation pipe has a length comprised between 2 and 12 meters.

[0094] Specifically, the secondary reactor heat exchanger that heated the effluent gas is oriented vertically within the effluent gas flow conduit.

[0095] In one embodiment of the invention, the apparatus includes at least two secondary reactors, the apparatus including a syngas heated secondary reactor as described above, and a tail gas heated secondary reactor as described above.

[0096] In one aspect of the invention, the secondary reactor includes a feed distribution header and a collection header.

[0097] In one embodiment of the invention, a feed distribution header is located at one end of the secondary reactor and a collection header is located at the opposite end of the secondary reactor.

[0098] In one embodiment of the invention, the feed distribution header is located at the top end of the secondary reactor and the collection header is located at the bottom end of the secondary reactor, so that the flow direction of the ammonia feed stream is downward to prevent fluidization of the catalyst.

[0099] In one aspect of the invention, the feed distribution header and the collection header are at the same end as the secondary reactor.

[0100] In one aspect of the invention, the secondary reactor is supported by one of its ends and the other end of said secondary reactor is unsupported. In other words, the other end is free and can expand freely inside the exit gas flow conduit to compensate for thermal elongation. This also reduces the need for auxiliary supports and any other suspension measures.

[0101] In one aspect of the invention, the secondary reactor comprises an opening at one end of the heat exchanger arranged to load the catalyst into the heat exchanger, specifically into the first gas circulation section.

[0102] In one aspect of the invention, the opening is located in the supply distribution header.

[0103] In one aspect of the invention, the primary catalyst and / or secondary catalyst are selected from among the pellet catalysts of the constructed catalyst.

[0104] Further features, details and advantages of the invention will become more apparent upon reading the description given below and with reference to the drawings. [Brief explanation of the drawings]

[0105] [Figure 1] FIG. 1 is a schematic diagram of the process of the present invention according to a first embodiment. [Figure 2] FIG. 2 is a schematic diagram of the process of the present invention according to a second embodiment. [Figure 3] FIG. 3 is a schematic diagram of an apparatus of the present invention according to a first embodiment. [Figure 4] FIG. 4 is a schematic diagram of an apparatus of the present invention according to a second embodiment. [Figure 5] FIG. 5 is a schematic diagram of a secondary reactor of the apparatus of FIG. 3 or FIG. 4 according to a first embodiment. [Figure 6] FIG. 6 is a schematic diagram of a secondary reactor of the apparatus of FIG. 3 or FIG. 4 according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0106] It should first be noted that the drawings disclose the invention in detail as it is put into practice, and said drawings may of course serve to define the invention more clearly where necessary.

[0107] 1 is a schematic diagram of a process for producing a synthesis gas product comprising hydrogen from the endothermic decomposition reaction of an ammonia feedstream according to a first embodiment of the present invention. In this embodiment, the process 100 comprises the following steps: providing an ammonia feed stream 101; heating the primary reactor in a heating step 109 by a combustion reaction 106 of the fuel gas stream into a combustion reaction effluent gas stream, said combustion occurring in a calcination chamber; converting the partially converted ammonia stream in a heated primary reactor by primary catalytic endothermic conversion of the partially converted ammonia stream 103; Venting the effluent gas stream produced by the heating step 109 and / or by the primary catalytic endothermic conversion 103; recovering heat from the effluent gas stream in a heat recovery step 111; redirecting the recovered heat 113, 114 to at least one secondary reactor in which a secondary catalytic endothermic conversion of the ammonia feed stream occurs 104; transferring the redirected heat to a secondary catalytic endothermic conversion through a thermally conductive layer at least partially defining the gas reaction region in a heat transfer step. Includes:

[0108] In this embodiment, the secondary catalytic conversion 104 is a pre-cracking reaction, where the secondary catalytic conversion 104 is upstream of the main catalytic conversion 103 in the flow direction of the ammonia feed stream, and the ammonia feed stream is converted by the secondary catalytic conversion 104 to a partially converted ammonia stream, which is then converted by the main catalytic endothermic conversion 103 to a synthesis gas product.

[0109] The secondary catalytic conversion 104 is carried out here at a temperature comprised between 350°C and 650°C, preferably at a temperature of about 550°C, and the main catalytic conversion 103 is carried out at a temperature comprised between 600°C and 900°C, preferably between 700°C and 800°C, for example at a pressure of about 30 bar A. The lower temperature of the secondary catalytic conversion makes it possible to use a catalyst different from that of the main catalytic conversion and thus to improve the field of the cracking reaction.

[0110] The conversion rate of the secondary catalytic conversion is comprised between 15% and 90%, preferably between 15% and 50%, preferably between 15% and 20%. The conversion rate of the primary catalytic conversion is about 93%.

[0111] The primary catalytic conversion 103 is carried out in the presence of an active catalyst that promotes the conversion of the ammonia stream partially converted during the cracking reaction, with heat provided to the catalytic conversion 109. The primary catalyst comprises nickel as the catalytically active material, specifically on a support of, for example, aluminum oxide (Al2O3). The primary catalyst comprises 5-20 wt% nickel, preferably about 15 wt% nickel.

[0112] The secondary catalytic conversion 104 occurs in the presence of a catalyst that promotes the conversion of the ammonia feed stream into a partially converted ammonia feed stream during the pre-cracking reaction. The secondary catalytic conversion occurs in a secondary reactor in the presence of a catalyst that includes nickel as the catalytically active material, specifically on a support, for example, of aluminum oxide (Al2O3). The secondary catalyst includes more than 20 wt% to more than 45 wt% nickel, preferably more than 35 wt% nickel, and / or a noble metal-based catalyst, such as a ruthenium-based catalyst, preferably 1.5 wt% ruthenium. The use of noble metal catalysts is facilitated because the feedstock primarily contains ammonia with sub-ppm levels of impurities.

[0113] The secondary catalytic conversion occurs in a secondary reactor arranged within the effluent gas conduit, where the effluent gas stream is heated and configured to distribute the effluent gas stream around the heated secondary reactor to recover 111 heat for directing 113 the effluent gas stream from the effluent gas conduit to the secondary catalytic conversion 104.

[0114] Following primary catalytic conversion 104, a synthesis gas product includes hydrogen, nitrogen, and possibly a portion of the unrecovered ammonia feedstock. Synthesis gas is the product of the endothermic decomposition reaction of ammonia. Thus, "synthesis gas product" refers to the cracked gas product containing hydrogen and nitrogen. The synthesis gas product is hot due to the heat provided to the catalytic reaction. The process includes recovering heat from the synthesis gas product 112 and directing the recovered heat from the synthesis gas product to secondary catalytic conversion 104 in another secondary reactor, referred to herein as the synthesis gas heated secondary reactor, in step 114. During this step, the synthesis gas product circulates within the synthesis gas heated secondary reactor and exchanges heat with an ammonia feed stream that also circulates within the synthesis gas heated secondary reactor. For example, the synthesis gas product circulates in a first portion of a heat exchanger contained in the synthesis gas product of the secondary reactor, and the ammonia feed stream circulates in another portion of the heat exchanger, with the first and second portions separated by a thermally conductive layer that allows heat exchange between the two fluids. These steps can reduce the amount of bleed gas required.

[0115] The process of the present invention includes a secondary reaction taking place in a synthesis gas heated secondary reactor, which now includes a heat exchanger for exchanging heat between the synthesis gas product and an ammonia feed stream, and a secondary reaction taking place in an effluent gas heated secondary reactor arranged to exchange heat between the effluent gas stream circulating in an effluent gas stream conduit and the ammonia feed stream.

[0116] The process may also include controlling the rate of the fuel gas flow depending on the flow rates of the feedstock streams. As the flow rate of the ammonia feedstock stream decreases, the flow rate of the fuel gas stream also decreases. The flow rates are thus controlled to obtain the desired temperatures at the primary and secondary catalytic conversions and, therefore, the desired synthesis gas product rates.

[0117] The process 100 also includes conditioning the ammonia feed stream 102, for example, by vaporizing the ammonia feed stream.

[0118] The process 100 can also include a step of discharging a synthesis gas product 107. During this step, the synthesis gas product is discharged from the reactor where the catalytic reaction occurs for processing, if necessary, in a processing step 108. For example, this processing step can be a purification step. This purification step uses traditional purification methods such as PSA, cryogenic separation, membrane, TSA, etc. Purified hydrogen is thus obtained.

[0119] 2 is a schematic diagram of a process for producing a synthesis gas product comprising hydrogen from the endothermic decomposition reaction of an ammonia feedstream according to a first embodiment of the present invention. In this embodiment, process 200 includes the following steps: providing an ammonia feed stream 201; heating the primary reactor in a heating step 209 in a combustion reaction 206 of the fuel gas stream into a combustion reaction effluent gas stream, said combustion occurring in a calcination chamber; converting an ammonia stream by primary catalytic endothermic conversion of an ammonia feed stream 203 in a primary reactor; venting the effluent gas stream 210 produced by the heating step 209 and / or by the primary catalytic endothermic conversion 203; recovering heat from the effluent gas stream in a heat recovery step 211; redirecting the heat 213, 214 recovered in the heat redirection step to at least one secondary reactor, the secondary reactor including a gas reaction section in which a secondary catalytic endothermic conversion of the ammonia feed stream occurs; transferring the redirected heat to a secondary catalytic endothermic conversion through a thermally conductive layer at least partially defining the gas reaction region in a heat transfer step. Includes:

[0120] In this embodiment, the secondary catalytic conversion 204 occurs in parallel with the main catalytic conversion 203. In this case, the ammonia feed stream is split 215 into two split ammonia feed streams, one of which is provided to the main reactor for the main catalytic endothermic conversion 203, and the other split ammonia feed stream is provided to the secondary reactor for the secondary catalytic endothermic conversion 204. The secondary catalytic conversion 204 is achieved simultaneously with the main catalytic conversion 203. The ammonia feed stream is then converted to synthesis gas products by the main catalytic conversion 203 and the secondary catalytic conversion 204.

[0121] In this case, the main catalytic conversion 203 can be carried out at the same temperature as the secondary catalytic conversion 204. The main catalytic conversion 203 can also be carried out at a different temperature than the secondary catalytic conversion 204. The main catalytic conversion 203 and the secondary catalytic conversion 204 can be carried out in the presence of the same catalyst or different catalysts. The catalyst is a catalyst comprising nickel as a catalytically active material, specifically on a support of, for example, aluminum oxide (Al2O3). For example, the catalyst comprises 5-20 wt% nickel, preferably about 15 wt% nickel. Preferably, the conversion rates of the secondary catalytic conversion 204 and the main catalytic conversion 203 are similar.

[0122] The secondary catalytic conversion 204 and the main catalytic conversion 203 are carried out here at temperatures comprised between 600 and 700°C.

[0123] The secondary catalytic conversion occurs in a secondary reactor, referred to as the effluent gas heated secondary reactor, arranged within an effluent gas conduit configured to distribute the effluent gas stream around the effluent gas heated secondary reactor for heat recovery 211 for discharging and redirecting 213 the effluent gas stream from the effluent gas stream conduit to secondary catalytic conversion 204.

[0124] Following primary catalytic conversion 204, a synthesis gas product comprises hydrogen, nitrogen, and possibly a portion of the unrecovered ammonia feedstock. Synthesis gas is the product of the endothermic decomposition reaction of ammonia. Thus, "synthesis gas product" refers to the cracked gas product comprising hydrogen and nitrogen. The synthesis gas product is hot due to the heat provided to the catalytic reaction. The process includes recovering heat from the synthesis gas product 212 and directing the recovered heat from the synthesis gas product to secondary catalytic conversion 204 in another secondary reactor, referred to as the synthesis gas heated secondary reactor, in step 214. During this step, the synthesis gas product circulates within the synthesis gas heated secondary reactor and exchanges heat with an ammonia feed stream that also circulates within the synthesis gas heated secondary reactor. For example, the synthesis gas product circulates in a first portion of a heat exchanger contained within the synthesis gas heated secondary reactor, and the ammonia feed stream circulates in another portion of the heat exchanger, with the first and second portions separated by a thermally conductive layer that allows heat exchange between the two fluids. These steps can reduce the amount of bleed gas required.

[0125] The process of the present invention includes a secondary reaction taking place in a synthesis gas heated secondary reactor, which now includes a heat exchanger for exchanging heat between the synthesis gas product and the ammonia feed stream, and a secondary reaction taking place in an effluent gas heated secondary reactor arranged to exchange heat between the effluent gas stream and the ammonia feed stream.

[0126] The process may also include controlling the rate of the fuel gas flow depending on the flow rates of the feed streams. As the flow rate of the ammonia feed stream decreases, the flow rate of the fuel gas stream also decreases. The flow rates are thus controlled to obtain the desired temperatures in the primary and secondary endothermic decomposition reactions and, therefore, the desired synthesis gas product rate.

[0127] The process 200 also includes conditioning the ammonia feed stream 202, for example, vaporizing the ammonia feed stream.

[0128] Process 200 can also include a step of discharging synthesis gas product 207. During this step, synthesis gas product is discharged from the primary and secondary reactors where catalytic reactions occur for processing, if necessary, in processing step 208. For example, this processing step can be a purification step. This purification step uses traditional purification methods such as PSA, cryogenic separation, membrane, TSA, etc. Purified hydrogen is thus obtained.

[0129] FIG. 3 is a schematic diagram of an apparatus according to a first embodiment.

[0130] In this embodiment, an apparatus 1 for producing a synthesis gas product comprising hydrogen by endothermic decomposition of an ammonia feed stream, said apparatus comprising: a primary reactor 2 configured to produce a synthesis gas product comprising hydrogen by primary endothermic catalytic conversion of the partially converted ammonia feedstream; a heating device, here a calcination chamber 4, arranged to provide heat to the primary reactor 2; an outlet gas conduit 5, 23 arranged to discharge an outlet gas stream from the primary reactor and / or from the heating device; at least one secondary reactor (3a, 3b) including a gas reaction section (19, 21) arranged to produce a partially converted ammonia feed stream by secondary endothermic catalytic conversion of the ammonia feed stream, said gas reaction section (19, 21) being at least partially bounded by a thermally conductive layer (20, 22) arranged to recover a portion of heat from the outlet gas stream in the outlet gas conduit (5, 23) and provide the recovered heat to the secondary catalytic conversion, said gas reaction section (19, 21) comprising a catalyst configured to promote the secondary catalytic conversion of the ammonia feed stream;

[0131] In this embodiment, secondary reactors 3 a, 3 b are positioned upstream of primary reactor 2 in the direction of flow of the ammonia feed stream. Apparatus 1 includes an ammonia feed stream inlet 9 positioned for the inlet of the ammonia feed stream. Apparatus 1 includes a partially converted ammonia feed stream conduit 14 positioned to deliver the partially converted ammonia feed stream from the secondary catalytic conversion, here a pre-cracking reaction, taking place in secondary reactors 3 a, 3 b, to primary reactor 2. Syngas product conduit 15 is positioned to discharge syngas product from primary reactor 2.

[0132] The secondary reactors 3a, 3b are here non-adiabatic reactors.

[0133] The syngas-heated secondary reactor 3a includes a heat exchanger 8 arranged to exchange heat between the syngas product from the main catalytic conversion and the feed gas stream circulating inside the secondary reactor 3. Here, the outlet gas conduit includes a syngas conduit 23 arranged to discharge the syngas product from the main reactor 2. In other words, the outlet gas includes the syngas product. Heat from the syngas product is thus transferred to the secondary reactor 8. For example, the heat exchanger 8 of the syngas secondary reactor 3a can be a fluid / fluid heat exchanger 8. In this case, the heat exchanger 8 includes a portion configured to circulate the ammonia feed stream and another portion configured to circulate the syngas product from the main catalytic conversion, the portions being separated by a heat-conducting layer arranged to exchange heat between the ammonia feed stream and the syngas product from the main catalytic conversion. The heat exchanger 8 can be, for example, a tube-and-shell heat exchanger. The heat exchanger includes a syngas conduit arranged to circulate the syngas product and a shell forming a conduit for circulating the ammonia feed stream.

[0134] The apparatus includes a calcination chamber 2, which includes a combustion zone 12 in which a fuel gas stream is combusted to produce a combustion reaction effluent gas. A fuel gas inlet 10 is configured to inject fuel gas into the calcination chamber 2. An effluent gas conduit includes an exhaust gas conduit 5 arranged to discharge the effluent, here an exhaust gas stream, and distribute the effluent gas around a heated secondary reactor 3b. The heated secondary reactor 3b is arranged vertically inside the effluent gas stream conduit 5.

[0135] The apparatus includes two partially converted ammonia feed conduits 24a, 24b arranged to discharge the partially converted ammonia feed from the secondary reactor and to feed the discharged partially converted ammonia feed to the primary reactor.

[0136] The secondary reactors 3a, 3b include a feed distribution header 6 and a partially converted ammonia feed stream collection header 7, which are disclosed in FIGS.

[0137] Primary reactor 2 contains a catalyst configured to promote catalytic conversion of the partially converted ammonia feed stream at a temperature comprised between 350°C and 650°C, preferably at a temperature of about 550°C.

[0138] The secondary reactors 3a, 3b are filled with a catalyst comprising nickel as catalytically active material, in particular on a support of aluminum oxide (Al2O3), for example, and containing more than 20 wt% to more than 45 wt% nickel, preferably more than 35 wt% nickel, and / or a catalyst comprising a noble metal, such as ruthenium, preferably on a support, preferably more than 1.5 wt% ruthenium, as catalytically active material.

[0139] FIG. 4 is a schematic diagram of an apparatus according to a second embodiment.

[0140] In this embodiment, there is provided an apparatus 1' for producing a synthesis gas product comprising hydrogen by endothermic decomposition of an ammonia feed stream, the apparatus comprising: a primary reactor 2' configured to produce a synthesis gas product comprising hydrogen by primary endothermic catalytic conversion of an ammonia feed stream; a heating device, here a calcination chamber 4′, arranged to provide heat to the main reactor 2′; an outlet gas conduit 5' arranged to discharge an outlet gas stream from the primary reactor 2' and / or from the heating device 4'; at least one secondary reactor (3a, 3b) including a gas reaction section (19', 21') arranged to produce a synthesis gas product comprising hydrogen by secondary endothermic catalytic conversion of an ammonia feed stream, said gas reaction section (19', 21') being at least partially bounded by a thermally conductive layer (20', 22') arranged to recover a portion of heat from an outlet gas stream in an outlet gas conduit and provide the recovered heat to the secondary catalytic conversion, said gas reaction section (19', 21') including a catalyst configured to promote the secondary catalytic conversion of the ammonia feed stream;

[0141] In this embodiment, secondary reactors 3a', 3b' are fluidly arranged parallel to primary reactor 2' in the direction of flow of the ammonia feed stream. The apparatus includes an ammonia feed stream inlet 9' arranged for the inlet of the ammonia feed stream. Apparatus 1' includes a first syngas product conduit 14' arranged to discharge syngas product from secondary reactors 3a', 3b' to primary unit 2'. A syngas product conduit 15' is arranged to discharge syngas product from primary reactor 2'.

[0142] The secondary reactors 3a', 3b' are here non-adiabatic reactors.

[0143] The syngas-heated secondary reactor 3a' includes a heat exchanger 8' arranged to exchange heat between the syngas product from the main catalytic conversion and the feed gas stream circulating within the secondary reactor 3'. Here, the effluent gas conduit includes a syngas conduit 23' arranged to discharge the syngas product from the main reactor 2'. In other words, the effluent gas includes the syngas product. Heat from the syngas conduit is thus transferred to the secondary reactor 8'. For example, the heat exchanger 8' of the syngas-heated secondary reactor 3a' can be a fluid / fluid heat exchanger 8'. In this case, the heat exchanger 8' includes a portion configured to circulate the ammonia feed stream and another portion configured to circulate the syngas product from the main catalytic conversion, the portions being separated by a thermally conductive layer arranged to exchange heat between the ammonia feed stream and the syngas product from the main catalytic conversion. The heat exchanger 8' can be, for example, a tube-and-shell heat exchanger as illustrated in FIG. 3.

[0144] The apparatus 1' includes an ammonia feed stream splitting zone 16' arranged to split the ammonia feed stream into at least two split ammonia feed streams, one of which is distributed to the primary reactor 2' and the other split ammonia feed stream is distributed to the secondary reactors 3a', 3b'.

[0145] The apparatus includes a calcination chamber 2', which includes a combustion zone 12' where combustion of a fuel gas stream into a flue gas occurs. A fuel gas inlet 10' is configured to inject a fuel gas stream into the calcination chamber. A fuel gas conduit is positioned to distribute fuel gas from the fuel gas inlet 10' to the calcination chamber 4'. Combustion generates heat, which is directed to a primary reactor 2' for primary catalytic conversion.

[0146] The apparatus includes an outlet gas conduit 5', including an exhaust gas conduit 5', positioned to exhaust an outlet gas stream, here an exhaust gas stream, from the calcination chamber and distribute the outlet gas around the heated secondary reactor 3b', which is positioned vertically inside the outlet gas stream conduit 5'.

[0147] The secondary reactors 3a', 3b' include a feed distribution header 6' and a syngas product collection header 7', which are disclosed in FIGS.

[0148] The primary reactor 2' and secondary reactors 3a', 3b' comprise catalysts configured to promote primary and secondary catalytic conversion of the ammonia feed stream at temperatures comprised between 600°C and 900°C, preferably between 700°C and 800°C, and at pressures comprised between, for example, 15 and 20 bar A. The primary reactor 2' and secondary reactors 3a', 3b' are filled with catalysts having the same composition.

[0149] The secondary reactors 3a', 3b' are filled with a catalyst comprising nickel as catalytically active material in the range of 5-20 wt% nickel, preferably about 15 wt% nickel, and / or a catalyst comprising a noble metal such as ruthenium as catalytically active material, preferably 1.5 wt% ruthenium.

[0150] Figures 5 and 6 are schematic diagrams of secondary reactors in an apparatus according to Figure 3 or 4. The secondary reactors 3a, 3b, 3a', 3b' are here arranged in the outlet gas conduits 5, 5'. In another embodiment, the secondary reactors are not arranged in the outlet gas flow conduits.

[0151] The secondary reactors 3a, 3b, 3a', 3b' comprise feed distribution headers 6, 6' and collection headers 7, 7'. The secondary reactors are filled with catalysts 17, 17'. The secondary reactors 3a, 3b, 3a', 3b' comprise heat exchangers 8, 8', which can be coil exchangers of fluid-fluid heat exchangers. The heat exchanger here comprises two tubes (FIG. 5) or three tubes (FIG. 6). The heat exchanger tubes have a diameter comprised between 1 and 3 inches and a length comprised between 2 and 12 meters.

[0152] The feed distribution headers 6, 6' are located at the ends of the secondary reactors 3a, 3b, 3a', 3b', and the collection headers 7, 7' are located at the opposite ends of the secondary reactors 3a, 3b, 3a', 3b'. The feed distribution headers 6, 6' are located at the top ends of the secondary reactors 3a, 3b, 3a', 3b', and the collection headers 7, 7' are located at the bottom ends of the secondary reactors 3a, 3b, 3a', 3b'. Therefore, the flow direction of the ammonia feed stream is downward to prevent fluidization of the catalysts 17, 17'.

[0153] In Figures 5 and 6, the secondary reactors 3a, 3b, 3a', 3b' are supported by one of their ends and the other end is unsupported. In other words, the other end is free to expand inside the outlet gas flow conduit to compensate for thermal expansion. This reduces the need for auxiliary supports and any other suspension means.

[0154] In Figure 5, secondary reactors 3a, 3b, 3a', 3b' include openings 18, 18' positioned to load catalyst into secondary reactors 3, 3'. Openings 18, 18' are positioned in feed distribution headers 6, 6'.

[0155] In FIG. 6, the secondary reactor 3a, 3b, 3a', 3b' includes two openings 18, 18' at one end of the heat exchanger, said openings 18, 18' being positioned to load the catalyst into the secondary reactor 3a, 3b, 3a', 3b'.

Claims

1. A process (100, 200) for producing a synthesis gas product comprising hydrogen from an endothermic decomposition reaction of an ammonia feedstream, comprising the steps of: providing an ammonia feed stream (101, 201); heating the primary reactor in a heating step (109, 209); converting the ammonia feed stream or the partially converted ammonia stream in the heated primary reactor by primary catalytic endothermic conversion (103, 203) of the ammonia feed stream or the partially converted ammonia stream; Venting an effluent gas stream produced by said heating step (109, 209) and / or by said primary catalytic endothermic conversion (103, 203); recovering heat from said effluent gas stream in a heat recovery step (111, 211); redirecting the recovered heat (113, 114, 213, 214) in a heat redirection step to at least one secondary reactor, the secondary reactor including a gas reaction section in which a secondary catalytic endothermic conversion of the ammonia feed stream occurs (104, 204); transferring the redirected heat to the secondary catalytic endothermic conversion through a thermally conductive layer at least partially defining the gas reaction region in a heat transfer step. Steps (100, 200) comprising:

2. 2. The process of claim 1, wherein the secondary catalytic conversion is upstream of the primary catalytic conversion in a flow direction of the ammonia feed stream, the ammonia feed stream being converted to the partially converted ammonia stream by the secondary catalytic endothermic conversion, and the partially converted ammonia stream being converted to the synthesis gas product by the primary catalytic endothermic conversion.

3. 3. The process (100) according to claim 1 or 2, wherein the secondary catalytic conversion (104) is carried out at a temperature comprised between 350°C and 650°C, preferably at a temperature of about 550°C, and the main catalytic conversion is carried out at a temperature comprised between 600°C and 900°C, preferably between 700°C and 800°C, for example at a pressure of about 30 bar A.

4. The process (100) of any one of claims 1 to 3, wherein the primary catalytic conversion (103) occurs in the primary reactor where a primary catalyst is present and the secondary catalytic conversion occurs in the secondary reactor where a secondary catalyst is present.

5. 1. An apparatus (1,1) for producing a synthesis gas product comprising hydrogen by endothermic decomposition of an ammonia feed stream, comprising: a primary reactor (2, 2') arranged to produce a synthesis gas product comprising hydrogen by primary endothermic catalytic conversion of said ammonia feed stream or partially converted ammonia stream; a heating device (4, 4') arranged to provide heat to said primary reactor; an outlet gas conduit (5, 5', 23, 23') arranged to discharge an outlet gas stream from said primary reactor (2, 2') and / or from said heating device (4, 4'); 1. An apparatus (1, 1) comprising at least one secondary reactor (3a, 3b, 3a', 3b') comprising a gas reaction section (19, 21, 19', 21') comprising a catalyst configured to promote a secondary catalytic conversion of the ammonia feed stream to the synthesis gas product or to the partially converted ammonia stream, the gas reaction section (19, 21, 19', 21') being at least partially bounded by a thermally conductive layer (20, 22, 20', 22') arranged to recover a portion of the heat from the effluent gas stream in the effluent gas conduit and provide the recovered heat to the catalyst.

6. 6. The apparatus (1) according to claim 5, wherein the secondary reactors (3a, 3b) are arranged upstream of the primary reactor (2) in the direction of flow of the ammonia feed stream.

7. 7. The apparatus (1) according to claim 5 or 6, comprising a partially converted ammonia feed conduit (24a, 24b) arranged to discharge partially converted ammonia feed from the secondary reactor (3a, 3b) and to feed the discharged partially converted ammonia feed to the primary reactor.

8. 8. Apparatus (1) according to any one of claims 5 to 7, wherein the primary reactor comprises a primary catalyst configured to promote the primary catalytic conversion, and the catalyst contained in the secondary reactor is a secondary catalyst, the primary catalyst (2) being configured to enable the primary catalytic conversion of the partially converted ammonia feed stream at a temperature comprised between 600°C and 900°C, preferably between 700°C and 800°C, for example at a pressure of about 30 bar A.

9. 9. Apparatus (1) according to any one of claims 5 to 8, wherein the catalyst (3a, 3b) is configured to enable the secondary catalytic conversion of the ammonia feed stream at a temperature comprised between 350°C and 650°C, preferably at a temperature of about 550°C, for example at a pressure of about 30 bar A.

10. 10. Apparatus (1) according to any one of claims 5 to 9, wherein the catalyst comprises a noble metal as catalytically active material, such as more than 20 wt% to more than 45 wt% nickel, preferably more than 35 wt% nickel, and / or ruthenium, preferably more than 1.5 wt% ruthenium.

11. 11. The apparatus (1) according to any one of claims 5 to 10, wherein the outlet gas conduit comprises a synthesis gas conduit arranged to discharge the synthesis gas product from the primary reactor, and the at least one secondary reactor comprises a synthesis gas heated secondary reactor (3a, 3b), and the synthesis gas conduit comprises a synthesis gas product circulation section arranged in heat exchange relationship with the gas reaction section, the gas reaction section being delimited from the synthesis gas product circulation section by the thermally conductive layer.

12. The apparatus (1) according to any one of claims 5 to 11, wherein the heating device comprises a calcination chamber (4, 4') configured for the combustion of a fuel gas stream into an exhaust gas stream, and the outlet gas conduit comprises an exhaust gas conduit (5, 5') configured for discharging the exhaust gas from the calcination chamber (4, 4').

13. 13. The apparatus (1) according to any one of claims 5 to 12, wherein the at least one secondary reactor comprises an exhaust gas heated secondary reactor (3b, 3b'), and the gas reaction section comprises at least one feed circulation pipe arranged for the circulation and reaction of the ammonia feed stream, the feed circulation pipe being filled with the catalyst and arranged to exchange heat with the exhaust gas discharged from the calcination chamber in the exhaust gas conduit (5, 5'), the feed circulation pipe preferably having a coil shape.

14. 14. The apparatus (1) according to any one of claims 5 to 13, wherein the feed circulation pipe extends through a circulation section of the exhaust gas conduit (5, 5'), the exhaust gas conduit (5, 5') being configured to distribute the exhaust gas flow around the feed circulation pipe.

15. The apparatus (1) according to any one of claims 13 or 14 and claim 11, wherein the apparatus comprises at least two secondary reactors, one of which is a tail gas heated secondary reactor according to any one of claims 13 or 14, and another of which is a synthesis gas heated secondary reactor according to claim 11.

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