Chemical product synthesis system

Abstract

Provided is a chemical product synthesis system for synthesizing a chemical product from a raw material gas, the chemical product synthesis system comprising: a supply line capable of supplying the raw material gas; and a plurality of synthesis units connected in parallel to the supply line and performing a synthesis reaction of the chemical product using the raw material gas.

Description

Chemical product synthesis system

[0001] The present invention relates to a chemical product synthesis system.

[0002] Conventionally, various techniques have been proposed for the synthesis of chemical products such as hydrocarbons and ammonia. For example, Patent Document 1 discloses an ammonia production plant additionally provided with an ammonia production increase system for further producing ammonia using a purge gas. In addition, Patent Document 2 discloses an ammonia apparatus in which each of a hydrogen production unit, a nitrogen production unit and an ammonia production unit is containerized.

[0003] Japanese Unexamined Patent Application Publication No. 2018-203602 Japanese Translation of PCT International Application Publication No. 2024-520877

[0004] However, in Patent Document 1, when designing an ammonia production plant with a scale corresponding to a desired production scale, it is necessary to design the ammonia production plant together with the additionally installed ammonia production increase system, which may complicate the design of the ammonia production plant. Similarly, in Patent Document 2, when designing each of the hydrogen production unit, the nitrogen production unit and the ammonia production unit in accordance with a desired production scale, the design may also be complicated. Therefore, it has been desired to develop a chemical product synthesis system that can suppress complication of the design when designing the system in accordance with a desired production scale.

[0005] The present invention has been made to solve at least part of the above-mentioned problems, and an object of the present invention is to provide a technique capable of simplifying the design for accommodating the production scale.

[0006] The present invention has been made to solve at least part of the above-mentioned problems, and can be implemented as the following modes.

[0007] (1) According to one aspect of the present invention, a chemical product synthesis system is provided. This chemical product synthesis system is for synthesizing a chemical product from a raw material gas, and includes: a supply line capable of supplying the raw material gas; and a plurality of synthesis units connected in parallel to the supply line and configured to perform a synthesis reaction of the chemical product using the raw material gas.

[0008] According to this configuration, when designing a chemical product synthesis system with a scale corresponding to a desired production scale, various production scales can be accommodated by adjusting the number of synthesis units and designing supply lines in accordance with the number of synthesis units, whereby a chemical product synthesis system having a scale corresponding to the desired production scale can be easily designed. Therefore, according to this configuration, the design for accommodating production scales can be simplified.

[0009] (2) In the chemical product synthesis system of the above aspect, each of said synthesis units may have the same specifications. According to this configuration, since each of the synthesis units has the same specifications, the cost required for constructing the chemical product synthesis system can be reduced, whereby the manufacturing cost of the chemical product can be reduced.

[0010] (3) In the chemical product synthesis system of the above aspect, said synthesis unit includes: a reactor that accommodates a catalyst for promoting said synthesis reaction using said raw material gas; a separator that separates a delivery gas delivered from said reactor into said chemical product and a residual gas obtained by separating said chemical product from said delivery gas; and a purge line capable of discharging at least a part of said residual gas to the outside of said synthesis unit, and said chemical product synthesis system may further include: a residual gas collecting line that collects said residual gas discharged from each of said synthesis units via said purge line; and a downstream synthesis unit that performs said synthesis reaction using said residual gas supplied via said residual gas collecting line. According to this configuration, in the downstream synthesis unit, a chemical product synthesis reaction is performed using the residual gas discharged from each of the synthesis units, whereby a chemical product can be synthesized using unreacted raw material gas contained in the residual gas. Therefore, the conversion rate, which is the rate at which the raw material gas supplied to the chemical product synthesis system is converted into the chemical product, can be improved.

[0011] (4) In the chemical synthesis system of the above form, the downstream synthesis unit may be of the same specifications as each of the synthesis units. With this configuration, since the downstream synthesis unit is of the same specifications as the synthesis unit, there is no need to design a separate device for reusing residual gas, and thus a chemical synthesis system that can reuse residual gas can be easily designed.

[0012] (5) In the chemical synthesis system of the above form, the synthesis unit further includes an internal supply line that can supply the raw material gas to the reactor from outside the synthesis unit, and a circulation line that can circulate the residual gas to the internal supply line, and the chemical synthesis system may further include a control unit that controls the proportion of the residual gas circulated to the internal supply line via the circulation line and the proportion of the residual gas discharged to the outside of the synthesis unit from the purge line in each of the synthesis units. With this configuration, the management of residual gas can be carried out according to the operating state of each of the synthesis units. Furthermore, since the amount of residual gas discharged via the purge line can be adjusted for each synthesis unit, the amount of residual gas used in the chemical synthesis reaction in the downstream synthesis unit can be finely adjusted.

[0013] Furthermore, the present invention can be realized in various forms, for example, as a chemical product synthesis plant, a chemical product synthesis apparatus, a chemical product manufacturing method, a chemical product synthesis method, a computer program for executing these apparatuses and methods, a server device for distributing this computer program, and a non-temporary storage medium storing the computer program.

[0014] This is an explanatory diagram illustrating the configuration of a chemical synthesis system according to an embodiment of the present invention. This is an explanatory diagram illustrating the internal configuration of the synthesis unit. This is an explanatory diagram illustrating the hydrogen flow rate in the synthesis of chemical products using the synthesis unit. This is an explanatory diagram showing the relationship between the inert gas concentration and the ratio of purge gas. This is an explanatory diagram showing the effect of the presence or absence of a downstream synthesis unit on the hydrogen utilization rate.

[0015] <Embodiment> Fig. 1 is an explanatory diagram illustrating the configuration of a chemical product synthesis system 1 as an embodiment of the present invention. The chemical product synthesis system 1 is an apparatus that synthesizes a chemical product from a raw material gas. In the present embodiment, the raw material gas contains hydrogen and nitrogen, and the chemical product is ammonia. The chemical product synthesis system 1 includes a supply line SL, a plurality of (n) synthesis units U １ , U ２ ...U ｎ－１ , U ｎ , a chemical product collection line GL1, a storage tank TN, a residual gas collection line GL2, a downstream synthesis unit U Ｄ , a chemical product delivery line DL1, a purge line DL2, and a control unit CT.

[0016] The supply line SL is connected to each of the synthesis units U １ , U ２ ...U ｎ－１ , U ｎ , and is a pipe that defines a flow path capable of supplying a raw material gas containing hydrogen and nitrogen. The downstream portion of the supply line SL is branched into a plurality of branches. Each of the synthesis units U １ , U ２ ...U ｎ－１ , U ｎ is connected in parallel to the supply line SL, and is a unit that performs a synthesis reaction of ammonia, which is a chemical product, using the raw material gas. Hereinafter, when the synthesis units U １ , U ２ ...U ｎ－１ , U ｎ are collectively referred to, they may be called synthesis units U. In the present embodiment, each of the synthesis units U has the same specifications. Details will be described later.

[0017] In each of the branched downstream portions of the supply line SL, regulating valves RV １ , RV ２ ...RV ｎ－１ , RV ｎ are provided. The regulating valves RV １ , RV ２ ...RV ｎ－１ , RV ｎ adjust the supply flow rate of the raw material gas to each of the synthesis units U.

[0018] Figure 2 is an explanatory diagram illustrating the internal configuration of the synthesis unit U. The synthesis unit U includes an internal supply line USL, a reactor 10, a discharge line OL, a separator 20, a chemical product discharge line UGL1, a circulation line CL, and a purge line UGL2.

[0019] The internal supply line USL connects the supply line SL to the reactor 10 and defines a flow path that allows the raw material gas to be supplied from the supply line SL, which is outside the synthesis unit U, to the reactor 10. The reactor 10 contains a catalyst that promotes the synthesis reaction of a chemical product (ammonia in this embodiment) using the raw material gas. In other words, the chemical product synthesis reaction in the synthesis unit U takes place in the reactor 10. The discharge line OL connects the reactor 10 to the separator 20 and defines a flow path that allows the gas discharged from the reactor 10 to be supplied to the separator 20. The gas discharged from the reactor 10 contains ammonia, which is a chemical product, as well as unreacted hydrogen and nitrogen. Hereafter, the gas discharged from the reactor 10 may be referred to as the discharge gas.

[0020] The separator 20 separates the discharge gas sent from the reactor 10 into a chemical product (ammonia in this embodiment) and the residual gas from which the chemical product has been separated. The residual gas contains unreacted hydrogen and nitrogen. In this embodiment, the separator 20 is a gas-liquid separator. The discharge gas sent from the reactor 10 to the separator 20, which is a gas-liquid separator, is cooled and separated into liquid ammonia, which is the chemical product, and the residual gas. Instead of a gas-liquid separator, the separator 20 may be an adsorbent containing an adsorbent material capable of adsorbing ammonia.

[0021] The chemical product delivery line UGL1 connects the separator 20 to the chemical product collection line GL1 (described later), and is a piping system that defines a flow path for delivering the chemical products from the separator 20 to the chemical product collection line GL1. The circulation line CL connects the separator 20 to the unit supply line USL, and is a piping system that defines a flow path for circulating the residual gas delivered from the separator 20 to the unit supply line USL. The purge line UGL2 branches off from the circulation line CL and is a piping system that defines a flow path for discharging at least a portion of the residual gas delivered from the separator 20 to the outside of the synthesis unit U. The purge line UGL2 is equipped with a control valve URV that adjusts the discharge flow rate of the residual gas discharged to the outside of the synthesis unit U.

[0022] As described above, in this embodiment, each of the composite units U is of the same standard. This means that each composite unit U has the same configuration as shown in Figure 2, and that the overall size of the composite unit U, as well as the shape and dimensions of each component, are all the same product specifications. In other words, each composite unit U does not need to be manufactured individually according to different standards; they can all be manufactured according to the same standard. Furthermore, each composite unit U is formed into a transportable box (container) shape.

[0023] Returning to the explanation of Figure 1, the chemical product collection line GL1 connects each of the synthesis units U to the storage tank TN (described later), and defines a flow path that collects the chemical products discharged from each of the synthesis units U via the chemical product discharge line UGL1 and then discharges them to the storage tank TN. The storage tank TN is a tank for storing chemical products. The residual gas collection line GL2 defines a flow path that collects the residual gases discharged from each of the synthesis units U via the purge line UGL2. The residual gas collection line GL2 is connected to the downstream synthesis unit U (described later). Ｄ It is connected to the downstream synthesis unit U, and the collected residual gas is sent to the downstream synthesis unit U Ｄ It can be supplied to.

[0024] Downstream synthesis unit U ＤThe downstream side of each synthesis unit U is provided and carries out the chemical synthesis reaction using residual gas supplied via the residual gas collection line GL2. Ｄ This is the same standard as each of the composite units U. That is, the downstream composite unit U Ｄ It is possible to manufacture each of the synthesis units U in accordance with the same specifications. Downstream synthesis unit U Ｄ Similar to the synthesis unit U, it includes a reactor (similar to reactor 10 of the synthesis unit U) containing a catalyst that promotes the synthesis reaction of a chemical product (ammonia in this embodiment) using a raw material gas. Therefore, it is possible to carry out the chemical product synthesis reaction using residual gas containing unreacted hydrogen and nitrogen.

[0025] The chemical product delivery line DL1 is connected to the downstream synthesis unit U Ｄ Connected to the downstream synthesis unit U Ｄ The chemical product discharged from the separator (see Figure 2, similar to separator 20) in the downstream synthesis unit U Ｄ This is piping that defines a flow path that allows the product to be discharged to the outside. The chemical product discharge line DL1 may be connected to the storage tank TN, or it may be connected to a storage tank other than the storage tank TN. The purge line DL2 is connected to the downstream synthesis unit U Ｄ Connected to the downstream synthesis unit U Ｄ At least a portion of the residual gas discharged from the separator (see Figure 2, similar to separator 20) is transferred to the downstream synthesis unit U Ｄ This is a pipe with a defined flow path that allows for discharge to the outside.

[0026] The control unit CT is a computer comprising ROM, RAM, and CPU, and performs various controls of the chemical synthesis system 1. The control unit CT also controls the proportion of residual gas circulated to the internal supply line USL via the circulation line CL and the proportion of residual gas discharged to the outside of the synthesis unit U from the purge line UGL2 in each of the synthesis units U. Specifically, the control unit CT adjusts the circulation flow rate of residual gas circulating to the internal supply line USL and the discharge flow rate of residual gas discharged to the outside of the synthesis unit U by controlling the control valve URV provided in the purge line UGL2 with respect to the residual gas sent from the separator 20. Furthermore, the control unit CT controls the control valve RV provided in the supply line SL １ RV ２ ...RV ｎ－１ RV ｎ By controlling this, the supply flow rate of the raw material gas to each of the synthesis units U is also adjusted. Fn, Fn(1-a), Fna, additional raw material gas, F-Fna, F(1-a), and Fa shown in Figure 1 will be described later.

[0027] Figure 3 is an explanatory diagram of the hydrogen flow rate in the synthesis of chemical products using the synthesis unit U. In the explanation of Figure 3, if F is the flow rate of hydrogen in the raw material gas supplied to one synthesis unit U, and a is the proportion of residual gas discharged from the purge line UGL2 to the outside of the synthesis unit U in one synthesis unit U, then the flow rate of hydrogen in the residual gas discharged from the purge line UGL2 to the outside of the synthesis unit U is expressed as Fa. Hereafter, the residual gas discharged from the purge line UGL2 to the outside of the synthesis unit U may be called purge gas. On the other hand, the flow rate of hydrogen in the chemical product discharged from the chemical product discharge line UGL1 to the outside of the synthesis unit U is expressed as F(1-a).

[0028] Figure 4 is an explanatory diagram showing the relationship between the inert gas concentration in the raw material gas supplied to the reactor 10 and the proportion of purge gas. In Figure 4, the vertical axis represents the inert gas concentration in the raw material gas supplied to the reactor 10, and the horizontal axis represents the proportion of purge gas among the residual gas discharged from the separator 20.

[0029] Chemical synthesis system 1 is a system for producing ammonia as a chemical product. Generally, the conversion rate of ammonia synthesis is low, so in chemical synthesis system 1, residual gas containing unreacted hydrogen and nitrogen is supplied again to reactor 10 as raw material gas via the circulation line CL and the unit supply line USL. At this time, inert gases such as argon contained in the raw material gas are not used in the ammonia synthesis reaction in reactor 10 and are not sent out of the synthesis unit U from the chemical product delivery line UGL1. Therefore, the concentration of inert gas in the raw material gas circulating in the circulation line CL and the unit supply line USL increases each time the raw material gas is circulated. This increase in the concentration of inert gas in the raw material gas is undesirable because it inhibits the ammonia synthesis reaction.

[0030] Considering the inert gas concentration in the raw material gas, the control unit CT in the chemical synthesis system 1 controls the proportion of residual gas circulated to the in-unit supply line USL via the circulation line CL and the proportion of residual gas (purge gas) discharged to the outside of the synthesis unit U from the purge line UGL2. That is, by making at least a portion of the residual gas sent from the separator 20 into purge gas, the increase in the inert gas concentration in the raw material gas circulating within the synthesis unit U is suppressed. As shown in Figure 4, the higher the proportion of purge gas, the lower the value of the inert gas concentration in the raw material gas circulating within the synthesis unit U. On the other hand, since the purge gas contains unreacted hydrogen and nitrogen, the higher the proportion of purge gas, the more raw materials (hydrogen and nitrogen) for the synthesis reaction are discarded.

[0031] In this regard, in the chemical synthesis system 1, the residual gas discharged from each of the synthesis units U is collected by the residual gas collection line GL2, and then the collected residual gas is used as a raw material gas in the downstream synthesis unit U Ｄ It is used in the ammonia synthesis reaction in [location]. Therefore, even if the proportion of purge gas is increased to suppress the increase in the inert gas concentration in the raw material gas circulating within the synthesis unit U, that purge gas will be absorbed by the downstream synthesis unit U. ＤBecause it can be reused in the ammonia synthesis reaction, the amount of waste generated from the synthesis reaction can be reduced.

[0032] Furthermore, in the chemical synthesis system 1, the purge gas is supplied to the downstream synthesis unit U Ｄ Since it will be reused in the synthesis reaction, it is also possible to operate with a high proportion of purge gas in the synthesis unit U. In such operation, because the proportion of purge gas is set high, the inert gas concentration in the raw material gas circulating in the circulation line CL and the in-unit supply line USL is kept low, so that the ammonia synthesis reaction in the synthesis unit U can be carried out efficiently. Furthermore, when the proportion of purge gas is set high, the downstream synthesis unit U Ｄ Since the inert gas concentration in the purge gas supplied to the downstream synthesis unit U is also kept low, Ｄ The ammonia synthesis reaction in this region can also be carried out efficiently.

[0033] The terms Fn, Fn(1-a), Fna, additional raw material gas, F-Fna, F(1-a), and Fa shown in Figure 1 will be explained below. Similar to the explanation in Figure 3, when F is the flow rate of hydrogen in the raw material gas supplied to one synthesis unit U, and the chemical synthesis system 1 has n synthesis units U, Fn represents the total flow rate of hydrogen in the raw material gas supplied to each of the synthesis units U. Similar to the explanation in Figure 3, when a is the proportion of residual gas (purge gas) discharged from the purge line UGL2 to the outside of the synthesis unit U, and the chemical synthesis system 1 has n synthesis units U, Fna represents the total flow rate of hydrogen in the residual gas discharged from each of the synthesis units U. On the other hand, Fn(1-a) represents the total flow rate of hydrogen in the chemical product delivered from each of the synthesis units U.

[0034] The control unit CT adjusts the flow rate of additional raw material gas supplied to the residual gas collection line GL2 from piping (not shown) by referring to the amount of chemical product produced delivered to the storage tank TN, the flow rate and composition of the purge gas circulating in the residual gas collection line GL2. The various information referenced by the control unit CT is transmitted from sensors installed in the storage tank TN and the residual gas collection line GL2, respectively. In Figure 1, F-Fna shown below the additional raw material gas represents the flow rate of hydrogen in the supplied additional raw material gas. The supply of additional raw material gas to the collected residual gas causes the downstream synthesis unit U Ｄ The flow rate of hydrogen in the residual gas supplied to the system is F (= Fna + F - Fna).

[0035] Downstream synthesis unit U Ｄ Since the flow rate of hydrogen in the residual gas supplied to the downstream synthesis unit U is F, Ｄ The flow rate of hydrogen in the residual gas discharged from is denoted as Fa. Meanwhile, the downstream synthesis unit U Ｄ The flow rate of hydrogen in the chemical product discharged from is expressed as F(1-a).

[0036] Here, we will explain the hydrogen utilization rate in the chemical synthesis system 1. The total flow rate of hydrogen supplied to the chemical synthesis system 1 as a whole is the sum of the total flow rate Fn of hydrogen in the raw material gas supplied to each synthesis unit U and the flow rate F-Fna of hydrogen in the additional raw material gas supplied, so it can be expressed as Fn + F-Fna = F(n-na+1). On the other hand, the total flow rate of hydrogen used for the synthesis of chemicals in the chemical synthesis system 1 as a whole is the sum of the total flow rate Fn(1-a) of hydrogen in the chemicals delivered from each synthesis unit U and the downstream synthesis unit U Ｄ Since it is the sum of the flow rate F(1-a) of hydrogen in the chemical product discharged from the system, it can be expressed as Fn(1-a) + F(1-a) = F(1-a)(n+1). The hydrogen utilization rate corresponds to the value obtained by dividing the total flow rate F(1-a)(n+1) of hydrogen used in the synthesis of chemical products in the chemical product synthesis system 1 as a whole by the total flow rate F(n-na+1) of hydrogen supplied to the chemical product synthesis system 1 as a whole, and can be expressed as (1-a)(n+1) / (n-na+1) × 100 (%).

[0037] Figure 5 shows the downstream composite unit U Ｄ This diagram illustrates the impact of the presence or absence of a certain element on the hydrogen utilization rate. In Figure 5, the vertical axis represents the hydrogen utilization rate, and the horizontal axis represents the number of synthesis units U installed in the chemical synthesis system.

[0038] The solid line S shows the hydrogen utilization rate of the chemical synthesis system 1 of this embodiment. The dashed line D shows the hydrogen utilization rate of the chemical synthesis system of the comparative example. The chemical synthesis system of the comparative example consists of a residual gas collection line GL2 and a downstream synthesis unit U Ｄ The difference from the chemical synthesis system 1 of this embodiment is that it does not have a purge gas. That is, in the chemical synthesis system of the comparative example, the purge gas is supplied to the downstream synthesis unit U Ｄ It is discarded without being reused. Therefore, the hydrogen utilization rate in the comparative example's chemical synthesis system corresponds to the value obtained by dividing the total flow rate Fn(1-a) of hydrogen in the chemical product delivered from each of the synthesis units U by the total flow rate Fn of hydrogen in the raw material gas supplied to each of the synthesis units U, and is expressed as (1-a) / 1 × 100 (%).

[0039] The hydrogen utilization rates shown by the solid line S and the dashed line D are all values ​​when the purge gas ratio a is 5% (a = 0.05). As shown by the dashed line D, in the comparative example's chemical synthesis system, the hydrogen utilization rate remains constant regardless of whether the number of synthesis units U increases or decreases. Specifically, the hydrogen utilization rate in the comparative example's chemical synthesis system is constant at (1 - a) / 1 × 100 (%) = (1 - 0.05) / 1 × 100 (%) = 95 (%), regardless of the number of synthesis units U.

[0040] On the other hand, as shown by the solid line S, in the chemical synthesis system 1 of this embodiment, the hydrogen utilization rate increases as the number of synthesis units U increases. For example, when the number of synthesis units U is 1 (n=1), the hydrogen utilization rate in the chemical synthesis system 1 of this embodiment is (1-a)(n+1) / (n-na+1)×100(%) = (1-0.05)(1+1) / (10-10・0.05+1)×100(%) ≈ 97.4(%). When the number of synthesis units U is 10 (n=10), the hydrogen utilization rate in the chemical synthesis system 1 of this embodiment is (1-a)(n+1) / (n-na+1)×100(%) = (1-0.05)(10+1) / (10-10・0.05+1)×100(%) ≈ 99.5(%). Therefore, from the comparison of the dashed line D and the solid line S, the residual gas collection line GL2 and the downstream synthesis unit U Ｄ The advantages of having this feature were demonstrated.

[0041] According to the chemical synthesis system 1 described above, when designing a chemical synthesis system 1 on a scale corresponding to a desired production scale, various production scales can be accommodated by adjusting the number of synthesis units U and designing the supply line SL, chemical collection line GL1, and residual gas collection line GL2 according to the number of synthesis units U. Therefore, a chemical synthesis system 1 on a scale corresponding to a desired production scale can be easily designed. Accordingly, the chemical synthesis system 1 of this embodiment simplifies the design process to accommodate different production scales.

[0042] Furthermore, since each of the synthesis units U in the chemical synthesis system 1 is of the same specifications, the cost required to construct the chemical synthesis system 1 can be reduced, thereby lowering the manufacturing cost of the chemical products.

[0043] Furthermore, the chemical synthesis system 1 includes a residual gas collection line GL2 and a downstream synthesis unit U Ｄ It is equipped with the downstream synthesis unit U ＤIn this system, the chemical synthesis reaction is carried out using the residual gas (purge gas) discharged from each of the synthesis units U. Therefore, the chemical products can be synthesized using unreacted hydrogen and nitrogen contained in the residual gas (purge gas). This makes it possible to improve the conversion rate, which is the rate at which the raw material gas supplied to the chemical synthesis system 1 is converted into chemical products.

[0044] Furthermore, in the chemical synthesis system 1, the downstream synthesis unit U Ｄ Since it conforms to the same specifications as synthesis unit U, there is no need to design a separate device for reusing residual gas, making it possible to easily design a chemical synthesis system 1 that can reuse residual gas.

[0045] Furthermore, in the chemical synthesis system 1, the control unit CT controls the proportion of residual gas circulated to the in-unit supply line USL via the circulation line CL and the proportion of residual gas (purge gas) discharged to the outside of the synthesis unit U from the purge line UGL2 in each synthesis unit U. This allows for the management of residual gas according to the operating status of each synthesis unit U. The operating status here refers to, for example, the conversion rate. In synthesis units U with a high conversion rate, a large amount of chemicals are separated in the separator 20, and the concentration of inert gas in the residual gas tends to be high. Therefore, it is conceivable to suppress the increase in the concentration of inert gas in the raw material gas circulating within the synthesis unit U by setting a higher proportion of purge gas compared to synthesis units U with a low conversion rate.

[0046] Furthermore, in a chemical synthesis system 1 equipped with such a control unit CT, the amount of residual gas (purge gas) discharged via the purge line UGL2 can be adjusted for each synthesis unit U, so the downstream synthesis unit U ＤThe amount of residual gas (purge gas) used in the chemical synthesis reaction can also be finely adjusted. In other words, since the amount of residual gas (purge gas) discharged from each synthesis unit U can be individually adjusted for each synthesis unit U, for example, by finely adjusting the amount of residual gas (purge gas) discharged from one synthesis unit U while keeping the amount of residual gas (purge gas) discharged from other synthesis units U constant, the amount of residual gas (purge gas) discharged from the downstream synthesis unit U Ｄ This means that the amount of residual gas (purge gas) supplied can be precisely adjusted.

[0047] The chemical synthesis system 1 of this embodiment is a device for synthesizing ammonia as a chemical product. Conventionally, the Haber-Bosch process has been used as a method for synthesizing ammonia on a large scale and intensively. However, since hydrogen in the Haber-Bosch process is derived from fossil fuels, it generates a large amount of greenhouse gases, making the Haber-Bosch process a method with a high environmental burden. In recent years, as a countermeasure, a method of synthesizing hydrogen by water electrolysis using renewable energy has attracted attention. According to this method, since water and renewable energy are used in the production of hydrogen, no greenhouse gases are generated. However, since the supply of renewable energy fluctuates depending on the weather, etc., it is not suitable for use in large-scale, intensive ammonia synthesis that requires a stable energy supply.

[0048] In ammonia synthesis using renewable energy, a method of small-scale, decentralized ammonia synthesis can be considered. Specifically, it is conceivable to construct small-scale facilities corresponding to the expected renewable energy supply scale in each location. As such small-scale facilities, the chemical synthesis system 1 of this embodiment is suitable because, by adjusting the number of synthesis units U of the same specifications during the design phase, it can be easily designed to scale according to the expected renewable energy supply scale in each location. Therefore, when synthesizing ammonia on a small-scale, decentralized basis using renewable energy, adopting the chemical synthesis system 1 of this embodiment as a small-scale facility can reduce the cost required to construct multiple small-scale facilities, thereby also reducing the manufacturing cost of ammonia as a chemical product.

[0049] <Modifications of this Embodiment> The present invention is not limited to the above-described embodiments, and can be implemented in various forms without departing from the spirit of the invention. For example, the following modifications are also possible.

[0050] In the above embodiment, the chemical synthesis system is a device for synthesizing ammonia as a chemical product, and its raw material gas is hydrogen or nitrogen, but it is not limited to these. For example, the chemical synthesis system is a device for synthesizing hydrocarbons, alcohols, gasoline, etc., as chemical products, and its raw material gas may be hydrogen or carbon dioxide.

[0051] In the above embodiment, the circulation line CL was connected to the separator 20 and the purge line UGL2 branched off from the circulation line CL, but this is not limited to this configuration. For example, the purge line UGL2 may be connected to the separator 20 and the circulation line CL may branch off from the purge line UGL2. Also, in the above embodiment, a control valve URV was provided on the purge line UGL2, but instead of the control valve URV, or in addition to the control valve URV, a control valve may be provided on the part of the circulation line CL downstream of the point where it is connected to the purge line UGL2. The control unit CT may control the ratio of purge gas by controlling this control valve or the control valve URV.

[0052] In the above embodiment, one downstream synthesis unit U Ｄ While such a system was provided, it is not limited to this. The chemical synthesis system may be provided with multiple downstream synthesis units. In such a case, the downstream portion of the residual gas manifold line GL2 is branched into multiple parts, and each of the downstream synthesis units is connected in parallel to its downstream portion of the residual gas manifold line GL2.

[0053] In the above embodiment, each of the synthesis units U was of the same specifications, but this is not limited to this. Of course, from the viewpoint of reducing the cost required to construct the chemical synthesis system 1, it is preferable that each of the synthesis units U be of at least similar specifications, and even more preferably the same specifications. However, among the multiple (n units) of synthesis units U, there may be synthesis units U of different specifications from the other synthesis units U. Different specifications mean at least one of the following: the configuration is different from the configuration of the other synthesis units U (see Figure 2), or at least some of the product specifications, such as the overall size of the synthesis unit U and the shape and dimensions of each component, are different. Different configurations from the other synthesis units U include a different number of components, or even if the number of components is the same, some of the components are different (for example, different catalysts housed in the reactor).

[0054] In the above embodiment, the downstream synthesis unit U Ｄ The specifications were the same as those of synthesis unit U, but are not limited to this. Of course, from the standpoint of simply designing a chemical synthesis system 1 that can reuse residual gas, the downstream synthesis unit U Ｄ It is preferable that the downstream synthesis unit U is of the same specifications as the synthesis unit U. Ｄ The downstream synthesis unit U may be of a different standard. Ｄ In the residual gas used in the chemical synthesis reaction, the inert gas in the residual gas may become highly concentrated depending on the proportion of purge gas discharged to the outside of the synthesis unit U, therefore, the downstream synthesis unit U ＤThis may include a reactor containing a catalyst different from the catalyst contained in the reactor included in the synthesis unit U. Ｄ This can be said to be a different standard from the synthetic unit U.

[0055] The embodiments of this specification have been described above based on the embodiments and modifications described above. The embodiments described above are for the purpose of facilitating understanding of this specification and do not limit it. This specification may be modified and improved without departing from its spirit and the scope of the claims, and equivalents thereof are included in this specification. Furthermore, any technical features that are not described as essential in this specification may be deleted as appropriate.

[0056] The present invention can also be realized in the following forms: [Example 1] A chemical synthesis system for synthesizing a chemical product from a raw material gas, comprising: a supply line capable of supplying the raw material gas; and a plurality of synthesis units connected in parallel to the supply line and performing a synthesis reaction of the chemical product using the raw material gas. [Example 2] The chemical synthesis system according to Example 1, wherein each of the synthesis units is of the same specifications. [Application Example 3] A chemical synthesis system according to Application Example 1 or Application Example 2, wherein the synthesis unit includes: a reactor containing a catalyst that promotes the synthesis reaction using the raw material gas; a separator that separates the discharged gas sent from the reactor into the chemical product and the residual gas from which the chemical product has been separated from the discharged gas; and a purge line that can discharge at least a portion of the residual gas to the outside of the synthesis unit, and the chemical synthesis system further includes: a residual gas collection line that collects the residual gas discharged from each of the synthesis units via the purge line; and a downstream synthesis unit that performs the synthesis reaction using the residual gas supplied via the residual gas collection line. [Application Example 4] A chemical synthesis system according to any one of Application Examples 1 to 3, wherein the downstream synthesis unit is of the same specifications as each of the synthesis units. [Application Example 5] A chemical synthesis system according to any one of Application Examples 1 to 4, wherein the synthesis unit further includes: an internal supply line capable of supplying the raw material gas from outside the synthesis unit to the reactor; and a circulation line capable of circulating the residual gas to the internal supply line, and the chemical synthesis system further includes: a control unit in each of the synthesis units that controls the proportion of the residual gas circulated to the internal supply line via the circulation line and the proportion of the residual gas discharged from the purge line to the outside of the synthesis unit.

[0057] 1...Chemical synthesis system 10...Reactor 20...Separator CL...Circulation line CT...Control unit DL1...Chemical product delivery line DL2...Purge line GL1...Chemical product collection line GL2...Residual gas collection line OL...Delivery line RV １ RV ２ ...RV ｎ－１ RV ｎ ...Control valve SL...Supply line TN...Storage tank U １ , U ２ ...U ｎ－１ , U ｎ ...Synthesis Unit U Ｄ ...downstream synthesis unit UGL1...chemical product delivery line UGL2...purge line URV...control valve USL...in-unit supply line

Claims

1. A chemical synthesis system for synthesizing chemical products from a raw material gas, comprising: a supply line capable of supplying the raw material gas; and a plurality of synthesis units connected in parallel to the supply line and performing a synthesis reaction of the chemical product using the raw material gas.

2. A chemical synthesis system according to claim 1, wherein each of the synthesis units is of the same standard.

3. A chemical synthesis system according to claim 1 or claim 2, wherein the synthesis unit includes: a reactor containing a catalyst that promotes the synthesis reaction using the raw material gas; a separator that separates the discharge gas discharged from the reactor into the chemical product and the residual gas from which the chemical product has been separated from the discharge gas; a purge line that can discharge at least a portion of the residual gas to the outside of the synthesis unit; the chemical synthesis system further includes: a residual gas collection line that collects the residual gas discharged from each of the synthesis units via the purge line; and a downstream synthesis unit that carries out the synthesis reaction using the residual gas supplied via the residual gas collection line.

4. A chemical synthesis system according to claim 3, wherein the downstream synthesis unit is of the same specifications as each of the synthesis units.

5. A chemical synthesis system according to claim 3, wherein the synthesis unit further includes: an internal supply line capable of supplying the raw material gas from outside the synthesis unit to the reactor; and a circulation line capable of circulating the residual gas to the internal supply line, and the chemical synthesis system further includes: a control unit in each of the synthesis units that controls the proportion of the residual gas circulated to the internal supply line via the circulation line and the proportion of the residual gas discharged from the purge line to the outside of the synthesis unit.

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