Reactor Module

Abstract

A reactor module (15) comprises: a pre-reactor (20); and a membrane reactor (30) which is disposed downstream of the pre-reactor (20) and includes separation membranes (34). The pre-reactor (20) generates an intermediate gas from a raw material gas. The intermediate gas contains a liquid fuel, water vapour and the remaining raw material gas. The membrane reactor (30) generates a liquid fuel and water vapour from the remaining raw material gas. The separation membranes (34) allow the water vapour to pass therethrough, the water vapour being one of the products generated from the water vapour and the remaining raw material gas which are contained in the intermediate gas.

Description

[Technical field]

[0001] The present invention relates to a reactor module. [Background technology]

[0002] In recent years, membrane reactors have been developed that can improve the efficiency of conversion by separating the products in the conversion reaction from a feed gas containing hydrogen and carbon oxides to liquid fuels (such as methanol and ethanol).

[0003] Patent Document 1 discloses a membrane reactor that includes a flow path through which a raw material gas flows, a catalyst disposed in the flow path, and a separation membrane that allows permeation of water vapor, which is one of the products. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-008940 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the membrane reactor described in Patent Document 1, the amount of water vapor generated in the upstream region of the flow channel is small, and the separation membrane cannot be fully utilized, resulting in low cost performance of the separation membrane.

[0006] An object of the present invention is to provide a reactor module capable of improving the cost performance of a separation membrane. [Means for solving the problem]

[0007] The reactor module according to the present invention comprises a pre-reactor and a membrane reactor having a separation membrane, disposed downstream of the pre-reactor. The pre-reactor produces an intermediate gas containing liquid fuel, water vapor and remaining raw material gas from a raw material gas containing hydrogen and carbon oxides. The membrane reactor produces liquid fuel and water vapor from the remaining raw material gas. The separation membrane allows the water vapor contained in the intermediate gas and the water vapor produced from the remaining raw material gas to permeate. Effect of the Invention

[0008] According to the present invention, it is possible to provide a reactor module capable of improving the cost performance of a separation membrane. [Brief description of the drawings]

[0009] [Figure 1] Schematic diagram of a reactor module according to an embodiment. [Diagram 2] Schematic diagram of a reactor module according to a modified example. [Diagram 3] Schematic diagram of a reactor module according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] (Reactor System 100) A reactor system 100 according to an embodiment will be described below. Fig. 1 is a schematic diagram showing the configuration of the reactor system 100. The reactor system 100 includes a raw material gas source 10 and a reactor module 15.

[0011] The reactor module 15 includes a pre-reactor 20 and a membrane reactor 30. The pre-reactor 20 and the membrane reactor 30 may be housed in separate pressure-resistant containers, or may be housed together in one pressure-resistant container. It is more preferable to house the pre-reactor 20 and the membrane reactor 30 in separate pressure-resistant containers, since the temperatures of the pre-reactor 20 and the membrane reactor 30 can be controlled individually. Note that cross sections of the pre-reactor 20 and the membrane reactor 30 are shown in schematic form in FIG. 1.

[0012] [Raw gas source 10] The raw material gas source 10 is disposed upstream of the pre-reactor 20. The raw material gas source 10 stores a raw material gas. The raw material gas source 10 supplies the raw material gas to the pre-reactor 20. The raw material gas contains at least hydrogen and carbon oxide. At least one of carbon monoxide and carbon dioxide can be used as the carbon oxide. The raw material gas may be so-called synthesis gas (Syngas).

[0013] [Prereactor 20] The pre-reactor 20 is disposed downstream of the raw gas source 10. The pre-reactor 20 is disposed upstream of the membrane reactor 30. The raw gas is supplied to the pre-reactor 20 from the raw gas source 10. The pre-reactor 20 generates an intermediate gas by carrying out a conversion reaction from the raw gas to a liquid fuel. The pre-reactor 20 supplies the intermediate gas to the membrane reactor 30.

[0014] The liquid fuel is a fuel that is in a liquid state at normal temperature and pressure, or a fuel that can be liquefied under normal temperature and pressure. Examples of fuel that is in a liquid state at normal temperature and pressure include methanol, ethanol, and C n H 2(m-2n) (m is an integer less than 90, and n is an integer less than 30), and mixtures thereof. The liquid fuel generated in the pre-reactor 20 is in a gaseous state when generated, and is maintained in a gaseous state at least until it flows out of the pre-reactor 20. Examples of fuels that can be liquefied under normal temperature and pressure include propane, butane, and mixtures thereof.

[0015] For example, the reaction formula (1) when methanol is synthesized by catalytic hydrogenation of a raw material gas containing hydrogen and carbon dioxide in the presence of a catalyst is as follows. CO2+3H2⇔CH3OH+H2O (1)

[0016] The intermediate gas contains the liquid fuel produced by the conversion reaction, water vapor which is one of the products of the conversion reaction, and the remaining raw material gas which was not used in the conversion reaction. The content of water vapor in the intermediate gas can be determined according to the permeability of the separation membrane 34 of the membrane reactor 30 which will be described later. The content of the remaining raw material gas in the intermediate gas can be determined according to the conversion efficiency in the membrane reactor 30.

[0017] The operating temperature of the pre-reactor 20 is preferably higher than that of the membrane reactor 30. Since the pre-reactor 20 does not have a separation membrane, the operating temperature can be set to a temperature suitable for the catalytic activity of the first catalyst 23 without considering the heat resistance of the separation membrane. The operating temperature of the pre-reactor 20 can be, for example, 180°C or higher and 350°C or lower. The operating temperature of the pre-reactor 20 means the temperature of the intermediate gas flowing inside the part (hereinafter referred to as the "pre-reactor adjacent part") of the connecting pipe (not shown) between the pre-reactor 20 and the membrane reactor 30 that is close to the pre-reactor 20. The operating temperature of the pre-reactor 20 can be measured using a thermocouple, a resistance temperature detector, a thermistor, or the like. If it is difficult to measure the temperature of the intermediate gas flowing inside the pre-reactor adjacent part, a measurement part may be provided on the outer surface of the pre-reactor adjacent part, covered with a heat insulating material to reduce the influence of the outside air temperature, etc., and the temperature of the intermediate gas flowing inside may be estimated based on the measured temperature.

[0018] The pre-reactor 20 includes a reaction tube 21, a first flow path 22, and a first catalyst 23. The pre-reactor 20 does not include a separation membrane.

[0019] A first flow path 22 is formed inside the reaction tube 21. A raw material gas flows through the first flow path 22. A first catalyst 23 is disposed in the first flow path 22. The first catalyst 23 promotes the above-mentioned conversion reaction. An intermediate gas generated by the conversion reaction is collected from the first flow path 22. Note that, although the pre-reactor 20 according to this embodiment has three first flow paths 22, the number of the first flow paths 22 may be one or more.

[0020] A known catalyst suitable for a conversion reaction to a desired liquid fuel can be used as the first catalyst 23. Examples of the first catalyst 23 include metal catalysts (copper, palladium, etc.), oxide catalysts (zinc oxide, zirconia, gallium oxide, etc.), and catalysts made by combining these (copper-zinc oxide, copper-zinc oxide-alumina, copper-zinc oxide-chromium oxide-alumina, copper-cobalt-titania, and catalysts made by modifying these with palladium, etc.).

[0021] Although the configuration of the pre-reactor 20 has been described above, it is possible to appropriately change the configuration of the pre-reactor 20. As the pre-reactor 20, a known reactor not equipped with a separation membrane (for example, JP-A-2005-298413, JP-A-2010-13422, etc.) can be used.

[0022] [Membrane Reactor 30] The membrane reactor 30 is disposed downstream of the pre-reactor 20. The membrane reactor 30 is supplied with the intermediate gas from the pre-reactor 20. The membrane reactor 30 separates the water vapor generated in the pre-reactor 20 from the water vapor generated in the membrane reactor 30 while carrying out a conversion reaction (see reaction formula (1) above) from the residual raw material gas contained in the intermediate gas into liquid fuel. In this way, by carrying out the conversion reaction while separating the product, the reaction equilibrium of the above formula (1) can be shifted to the product side by utilizing the equilibrium shift effect. The liquid fuel generated in the membrane reactor 30 is in a gaseous state when it is generated, and is maintained in a gaseous state at least until it flows out of the membrane reactor 30.

[0023] The operating temperature of the membrane reactor 30 is set in consideration of the heat resistance of the separation membrane 34. The operating temperature of the membrane reactor 30 may be lower than the operating temperature of the pre-reactor 20. The operating temperature of the membrane reactor 30 may be, for example, 160°C or higher and 300°C or lower. The operating temperature of the membrane reactor 30 means the temperature of the liquid fuel flowing inside a portion (hereinafter referred to as the "membrane reactor adjacent portion") of an exhaust pipe (not shown) that discharges the liquid fuel from the membrane reactor 30 to the outside, which is adjacent to the membrane reactor 30. The operating temperature of the membrane reactor 30 can be measured using a thermocouple, a resistance temperature detector, a thermistor, or the like. If it is difficult to measure the temperature of the liquid fuel flowing inside the membrane reactor adjacent portion, a measurement portion may be provided on the outer surface of the membrane reactor adjacent portion, covered with a heat insulating material, and the temperature may be measured in a state where the influence of the outside air temperature, etc. is reduced, and the temperature of the liquid fuel flowing inside the portion may be estimated based on the measured temperature.

[0024] The membrane reactor 30 includes a porous support 31, a second flow path 32, a second catalyst 33, a separation membrane , and a third flow path .

[0025] The porous support 31 is made of a porous material. As the porous material, a ceramic material, a metal material, a resin material, or the like can be used, and a ceramic material is particularly suitable. Examples of aggregates of the ceramic material include alumina (Al2O3), titania (TiO2), mullite (Al2O3·SiO2), cerium oxide, and cordierite (Mg2Al4Si5O 18 ) can be used. As the inorganic binder for the ceramic material, for example, at least one of titania, mullite, sinterable alumina, silica, glass frit, clay mineral, and sinterable cordierite can be used. However, the ceramic material does not have to contain an inorganic binder.

[0026] The second flow passage 32 is formed in the porous support 31. The second flow passage 32 penetrates the porous support 31. Therefore, both ends of the second flow passage 32 open to the outer surface of the porous support 31. The second flow passage 32 is a space on the non-permeation side of the separation membrane 34.

[0027] An intermediate gas is passed through the second flow path 32. The intermediate gas contains the liquid fuel produced in the pre-reactor 20, the steam produced in the pre-reactor 20, and the remaining raw material gas that was not used in the conversion reaction in the pre-reactor 20. The membrane reactor 30 according to this embodiment has two second flow paths 32, but the number of the second flow paths 32 may be one or more.

[0028] The second catalyst 33 is disposed in the second flow path 32. The second catalyst 33 may be a known catalyst suitable for a conversion reaction to a desired liquid fuel. The second catalyst 33 promotes the conversion reaction. Examples of the second catalyst 33 include metal catalysts (copper, palladium, etc.), oxide catalysts (zinc oxide, zirconia, gallium oxide, etc.), and catalysts made by combining these (copper-zinc oxide, copper-zinc oxide-alumina, copper-zinc oxide-chromium oxide-alumina, copper-cobalt-titania, and catalysts made by modifying these with palladium, etc.).

[0029] Here, the second catalyst 33 is used for the conversion reaction of the remaining raw material gas contained in the intermediate gas. Therefore, the load on the second catalyst 33 can be reduced compared to when the second catalyst 33 is directly used for the conversion reaction of all the raw material gas. In this way, by having the first catalyst 23 of the pre-reactor 20 bear part of the load required for the conversion reaction of the raw material gas, the load on the second catalyst 33 of the membrane reactor 30 can be reduced, and the life of the second catalyst 33 can be extended.

[0030] The separation membrane is supported by the porous support 31. The separation membrane surrounds the second flow path 32. The separation membrane is disposed between the second flow path 32 and the third flow path .

[0031] The separation membrane 34 allows water vapor to permeate. Specifically, the separation membrane 34 allows water vapor originally contained in the intermediate gas and water vapor newly generated from the remaining raw material gas contained in the intermediate gas to permeate.

[0032] Here, in the upstream region of the second flow path 32, the amount of water vapor newly generated from the residual raw material gas is relatively small compared to the downstream region of the second flow path 32. Therefore, the upstream portion of the separation membrane 34 is mainly used for the permeation of water vapor originally contained in the intermediate gas, and the downstream portion of the separation membrane 34 is mainly used for the permeation of water vapor newly generated from the residual raw material gas. In this way, since the upstream portion of the separation membrane 34 can be utilized by performing the conversion reaction using the intermediate gas containing water vapor, the entire separation membrane 34 can be effectively utilized evenly. Therefore, the cost performance of the separation membrane 34 can be improved.

[0033] An inorganic membrane can be used as the separation membrane 34. Inorganic membranes are preferable because they have heat resistance, pressure resistance, and water vapor resistance. Examples of inorganic membranes include zeolite membranes, silica membranes, alumina membranes, and composite membranes of these. In particular, an LTA-type zeolite membrane in which the molar ratio (Si / Al) of silicon element (Si) to aluminum element (Al) is 1.0 or more and 3.0 or less is preferable because it has excellent water vapor permeability.

[0034] The separation membrane 34 has a molecular weight of 100 nmol / (s·Pa·m 2 The water vapor permeability coefficient can be determined by a known method (see Ind. Eng. Chem. Res., 40, 163-175 (2001)).

[0035] The separation membrane 34 preferably has a separation factor of 100 or more. The larger the separation factor, the easier it is for water vapor to permeate and the harder it is for components other than water vapor (such as hydrogen, carbon dioxide, and liquid fuel) to permeate. The separation factor can be determined by a known method (see FIG. 1 in "Separation and Purification Technology 239 (2020) 116533").

[0036] The third flow path 35 is formed in the porous support 31. The third flow path 35 penetrates the porous support 31. Therefore, both ends of the third flow path 35 are open. Third flow path 35 is the space on the permeate side of the separation membrane 34.

[0037] A sweep gas for sweeping the water vapor that has permeated the separation membrane 34 is passed through the third flow path 35. As the sweep gas, an inert gas (e.g., nitrogen) or air can be used. The membrane reactor 30 according to this embodiment has one third flow path 35, but the number of the third flow paths 35 may be one or more. No catalyst is disposed in the third flow path 35.

[0038] Although the configuration of the membrane reactor 30 has been described above, the configuration of the membrane reactor 30 can be appropriately changed. As the membrane reactor 30, a well-known tube-type reactor equipped with a separation membrane (for example, JP 2018-008940 A) or a monolith-type reactor can be used. The monolith means a structure having a plurality of holes penetrating in the longitudinal direction, and is a concept including a honeycomb.

[0039] (Modification of the embodiment) Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the gist of the invention.

[0040] [Variation 1] In the above embodiment, the reactor module 15 includes only one membrane reactor 30, but may include a plurality of membrane reactors 30.

[0041] For example, as in the reactor module 15a shown in Fig. 2, a plurality of membrane reactors 30 can be arranged in parallel. In this case, each membrane reactor 30 is connected to a pre-reactor 20. The intermediate gas generated in the pre-reactor 20 is distributed to each membrane reactor 30.

[0042] Also, as in the reactor module 15b shown in Fig. 3, a plurality of membrane reactors 30 can be arranged in series. In this case, the membrane reactor 30 located at the most upstream among the plurality of membrane reactors 30 is connected to the pre-reactor 20, and the remaining membrane reactors 30 are connected downstream thereof. The intermediate gas generated in the pre-reactor 20 is supplied to the membrane reactor 30 located at the most upstream. The product gas generated in each membrane reactor 30 is supplied to the other membrane reactors 30 located downstream. The product gas includes the liquid fuel and the remaining raw material gas. The product gas may include water vapor.

[0043] Furthermore, although not shown, multiple membrane reactors 30 may be arranged in a combination of parallel and series.

[0044] As described above, when multiple membrane reactors 30 are arranged downstream of the pre-reactor 20, part of the load required for the conversion reaction of the raw material gas can be borne by the first catalyst 23 of the pre-reactor 20, thereby reducing the load on the second catalyst 33 of each of the multiple membrane reactors 30.

[0045] [Variation 2] In the above embodiment, the sweep gas is caused to flow through the third flow passage 35, but the sweep gas does not necessarily have to be caused to flow through the third flow passage 35.

[0046] [Variation 3] In the above embodiment, the intermediate gas is directly supplied from the pre-reactor 20 to the membrane reactor 30, but it may be cooled before being supplied to the membrane reactor 30. For example, a cooling device (heat radiator or heat exchanger) may be disposed between the pre-reactor 20 and the membrane reactor 30, and the intermediate gas may be cooled in the cooling device.

[0047] [Variation 4] In the above embodiment, the separation membrane 34 is permeable to the water vapor generated in the pre-reactor 20 and the water vapor generated in the membrane reactor 30, but is not limited to this. The separation membrane 34 may be permeable to the liquid fuel that is the product in the pre-reactor 20 and the liquid fuel that is the product in the membrane reactor 30. Even in this case, the reaction equilibrium of the above formula (1) can be shifted to the product side.

[0048] In addition, when the separation membrane 34 allows liquid fuel to permeate, even when the liquid fuel is produced by a reaction that does not produce water vapor (for example, 2H2+CO⇔CH3OH), the reaction equilibrium can be shifted to the product side.

[0049] [Variation 5] In the above embodiment, the raw material gas containing hydrogen and carbon oxide is directly supplied to the pre-reactor 20. However, the raw material gas may be generated in the pre-reactor 20 and the generated raw material gas may be used to generate a liquid fuel.

[0050] For example, when ammonia and carbon dioxide are supplied to the pre-reactor 20, hydrogen, which is a part of the raw material gas, is produced from ammonia according to the following reaction formula (2), and methanol is produced from the raw material gas (hydrogen and carbon dioxide) according to reaction formula (3). Note that reaction formula (4) summarizes reaction formulas (2) and (3).

[0051] NH3 → 1 / 2N2O+3 / 2H2(2) CO2+4H2→ CH4+2H2O (3) CO2+8 / 3NH3→ CH4+4 / 3N2+2H2O (4) [Explanation of symbols]

[0052] 10. Raw gas source 15 Reactor Module 20 Pre-reactor 21 Reaction tube 22 First Channel 23 First Catalyst 30 Membrane Reactor 31 Porous support 32 Second flow path 33 Second Catalyst 34 Separation membrane 35 Third Stream

Claims

1. A pre-reactor; a membrane reactor disposed downstream of the pre-reactor and having a separation membrane; Equipped with The pre-reactor generates an intermediate gas containing a liquid fuel, water vapor, and a remaining raw material gas from a raw material gas containing hydrogen and carbon oxides; The membrane reactor produces liquid fuel and water vapor from the remaining raw material gas; the separation membrane allows a product produced in the pre-reactor and contained in the intermediate gas and a product produced from the remaining raw material gas in the membrane reactor to permeate; The pre-reactor and the membrane reactor are housed in separate pressure-resistant vessels. Reactor module.

2. The operating temperature of the pre-reactor is higher than the operating temperature of the membrane reactor; The reactor module of claim 1 .

3. the pre-reactor has a first flow path through which the raw material gas flows and a first catalyst disposed in the first flow path, The membrane reactor has a second flow path through which the intermediate gas flows, and a second catalyst disposed in the second flow path. The reactor module according to claim 1 or 2.

4. A plurality of the membrane reactors are provided, The plurality of membrane reactors are arranged in parallel. The reactor module according to claim 1 or 2.

5. A plurality of the membrane reactors are provided, The plurality of membrane reactors are arranged in series. The reactor module according to claim 1 or 2.

Images