JP2020023488A - Manufacturing method of methanol - Google Patents

Abstract

To provide a method for efficiently manufacturing methanol by installing a separation membrane in a methanol synthesis reactor by a conjugation method having good sealing property and durability under high temperature and high pressure in a presence of methanol steam.SOLUTION: There is provided a manufacturing method of methanol to obtain methanol by reacting a raw material gas containing at least hydrogen, carbon monoxide and/or carbon dioxide in the presence of a catalyst in a reactor, in which the reactor has a methanol permselective membrane which is conjugated with a dense member by a conjugation material mainly containing inorganic oxide and having linear expansion coefficient of 30×10/K to 90×10/K installed, and methanol generated by the reaction penetrates through the permselective membrane and is taken out.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing methanol.

A method for producing methanol from a gas containing hydrogen and carbon monoxide (hereinafter referred to as synthesis gas) has been known for a long time, and examples thereof include a method using a copper catalyst (copper-zinc catalyst, copper-chromium catalyst). Can be
The reaction for producing methanol from synthesis gas is an equilibrium reaction, and the lower the temperature and the higher the pressure, the more advantageous. Since the reaction rate is reduced when the temperature is lowered, a general methanol production process is performed under the severe conditions of 200 to 300 ° C. and 5 to 10 MPaG (or higher pressure), so that a large amount of energy is consumed during methanol production. In addition, the process has many restrictions on equipment.

  As a method for efficiently producing methanol, there have been proposed a plurality of methods for removing the methanol from the reaction system, shifting the gas composition in the reactor from the equilibrium composition, and performing the reaction at a conversion rate exceeding the equilibrium conversion rate. I have.

  Further, in Patent Documents 1, 2, 3, and 4, a separation membrane is installed in a methanol synthesis reactor, and methanol and water are removed from the reaction system using the separation membrane, so that the conversion rate is higher than the equilibrium conversion rate. A method of raising has been proposed.

  Further, Non-Patent Document 1 reports a method of installing a separation membrane sealed with graphite packing in a high-temperature and high-pressure methanol reactor.

Japanese Patent Publication No. Hei 9-511509 JP-A-2006-117726 JP-A-2006-174996 JP 2007-55970 A

Chem. Eng. Process. 43 (2004), 1029

In a method of installing a separation membrane in a methanol synthesis reactor as proposed in Patent Literatures 1, 2, 3, and 4, a gas supply side (high pressure) is applied to a gas at a high temperature and a high pressure and in the presence of methanol vapor. It is necessary to seal the permeation side (low pressure) for a long time, and a method of joining the separation membrane to other members is an issue. However, Patent Literatures 1, 2, and 3 do not describe a specific joining method, and do not describe Examples under high-temperature and high-pressure conditions.
Patent Document 4 describes an example in which water is removed from a methanol synthesis reactor using a separation membrane under high-temperature and high-pressure conditions of 200 ° C. and 3 MPaG, but a specific bonding method is also described. No sealability and durability are unknown.

The mechanical sealing method using graphite packing or the like described in Non-Patent Document 1 requires time and effort to tighten one by one when installing a membrane, requires a graphite packing casing, and has a large joint volume. Therefore, it is not suitable for industrial use. Further, the auxiliary agent used for molding graphite as a packing does not have durability against methanol vapor, and cannot be used for a long time.

  The present invention has been made under such circumstances, and a separation membrane is installed in a methanol synthesis reactor by a bonding method having good sealing properties and durability under high temperature, high pressure and in the presence of methanol vapor. Therefore, an object of the present invention is to provide a method for efficiently producing methanol.

  When producing methanol from a raw material gas containing hydrogen and carbon monoxide and / or carbon dioxide, the present inventors use a specific bonding material to form a methanol permselective membrane bonded to a dense member in a reactor. The present inventors have found that the above-mentioned problems can be solved by installing the present invention, and have completed the present invention.

That is, the gist of the present invention is as follows.
[1] A method for producing methanol, comprising reacting a raw material gas containing at least hydrogen, carbon monoxide and / or carbon dioxide in the presence of a catalyst in a reactor to obtain methanol,
In the reactor for performing the above reaction, the dense member was joined with a joining material containing an inorganic oxide as a main component and having a coefficient of linear expansion of 30 × 10 ⁻⁷ / K or more and 90 × 10 ⁻⁷ / K or less. A method for producing methanol, wherein a methanol permselective membrane is provided, and methanol produced by the reaction is extracted through the permselective membrane.
[2] The method for producing methanol according to [1], wherein the methanol permselective membrane is a zeolite membrane.
[3] The method for producing methanol according to [1] or [2], wherein the dense member is a metal. [4] The method for producing methanol according to any one of [1] to [3], wherein a partial pressure of methanol on a gas supply side of the methanol selective permeable membrane in the reactor is 0.1 MPa or more and 6 MPa or less. .
[5] The method for producing methanol according to any one of [1] to [4], wherein the temperature inside the reactor is 200 ° C or higher and 300 ° C or lower.
[6] The method for producing methanol according to any one of [1] to [5], wherein the pressure on the gas supply side of the methanol selective permeable membrane in the reactor is 1 MPaG or more and 8 MPaG or less.
[7] The method for producing methanol according to any one of [1] to [6], wherein the linear expansion coefficient of the dense member is 30 × 10 ⁻⁷ / K or more and 200 × 10 ⁻⁷ / K or less.
[8] The method for producing methanol according to any one of [1] to [7], wherein the dense member is Kovar.
[9] The method for producing methanol according to any one of [1] to [8], wherein the inorganic oxide is an inorganic glass or an inorganic adhesive.
[10] A methanol production apparatus used in a production method in which a raw material gas containing at least hydrogen, carbon monoxide and / or carbon dioxide is reacted in a reactor in the presence of a catalyst to obtain methanol. hand,
In the reactor for performing the above reaction, the dense member was bonded to the dense member by a bonding material containing an inorganic oxide as a main component and having a coefficient of linear expansion of 30 × 10 ⁻⁷ / K or more and 90 × 10 ⁻⁷ / K or less. An apparatus for producing methanol, having a structure in which a methanol permselective membrane is installed and methanol generated by the reaction permeates through the permselective membrane.

  According to the present invention, when producing methanol, at a high temperature and high pressure, and in the presence of methanol vapor, by a bonding method having good sealing properties and durability, a separation membrane is installed in a methanol synthesis reactor, and the reaction is performed. A method for efficiently producing methanol is provided by allowing methanol generated by the above to permeate and be extracted through the permselective membrane.

It is a cross section showing an embodiment of a reactor. FIG. 3 is a schematic cross-sectional view showing one embodiment in which a zeolite membrane and a flange of a pipe are joined by a joining material. FIG. 3 is a schematic cross-sectional view showing one mode in which a zeolite membrane and a pipe are joined by a joining material. FIG. 3 is a schematic cross-sectional view showing an embodiment in which a zeolite membrane and a reactor are joined by a joining material.

  Hereinafter, typical embodiments for carrying out the present invention will be specifically described. However, the present invention is not limited to the following embodiments, and various modifications may be made without departing from the gist of the present invention. Can be.

An embodiment of the present invention is a method for producing methanol, in which a raw material gas containing at least hydrogen, carbon monoxide and / or carbon dioxide is reacted in a reactor in the presence of a catalyst to obtain methanol.
The content ratio of hydrogen (H ₂ ) and carbon monoxide and / or carbon dioxide (also collectively referred to as CO _x ) contained in the raw material gas is not particularly limited, but usually H ₂ : CO _x is 4 by volume. : 6 to 9: 1, preferably 5: 5 to 8: 2.

The source gas may include a gas other than H ₂ and CO _x . The gas other than H ₂ and _{CO x, CH 4, C 2} H 4, C 2 H 6, C 3 H 6, C 3 H 8, C 4 H 8, C 4 H 10, H 2 O and the like mentioned However, the content of gases other than H ₂ and CO _x is usually 50% by volume or less.

  Known catalysts can be used as the catalyst used when producing methanol from the raw material gas. For example, a copper-based catalyst (copper-zinc-based catalyst, copper-chromium-based catalyst), a zinc-based catalyst, a chromium-based catalyst, aluminum System catalyst, and the like.

In the present embodiment, in the reactor for obtaining the methanol, a bonding material having an inorganic oxide as a main component and a linear expansion coefficient of 30 × 10 ⁻⁷ / K or more and 90 × 10 ⁻⁷ / K or less is used. A methanol permselective membrane joined to the dense member is provided. This will be described with reference to the drawings. In this specification, the coefficient of linear expansion of the bonding material is the coefficient of linear expansion of the bonding material after bonding (after sintering), and indicates the rate of change in the length direction of the solid with increasing temperature. . It can be carried out according to the method described in JIS Z 2285 (metal material), JIS R 1618 (ceramics) and the like. In the present specification, the coefficient of linear expansion is an average value at 30 ° C to 300 ° C.

FIG. 1 is a schematic sectional view showing one embodiment of a reactor in which the present invention is carried out.
The reactor 10 has a raw material feed inlet a, a permeated gas outlet b, and a non-permeated gas outlet c. Since the methanol production reaction is performed at a high temperature and a high pressure, the reactor 10 is made of a material that can withstand such an environment. There is only one inlet a, outlet b, and outlet c in the figure, but there may be more than one.
In the reactor 10, a zeolite membrane composite 1, which is a methanol selective permeable membrane, is installed. The type of the methanol permselective membrane is not particularly limited as long as it can selectively permeate methanol, but a zeolite membrane is typically used in many cases. Details of the zeolite membrane composite will be described later.

  The zeolite membrane composite 1 becomes a composite by forming a zeolite membrane on a porous support. The shape of the porous support is not limited to a tubular shape, and may be a column, a hollow column, or a hollow honeycomb. One end of the zeolite membrane composite 1 is sealed by a cap 2. And another end is connected to the pipe 3. The connection between the pipe 3 and the zeolite composite 1 and the connection between the cap 2 and the zeolite composite 1 are joined by a joining material described later. The connection method of the zeolite membrane composite is not limited to the above. For example, both ends may be connected to a pipe so that the gas can flow inside.

  A catalyst 13 is disposed around the zeolite membrane composite 1 having a tubular shape. The raw material gas fed from the feed inlet a is brought into contact with the catalyst 13 to promote the production of methanol. Then, the generated methanol permeates through the zeolite membrane of the zeolite membrane composite 1, whereby higher purity methanol can be obtained. Furthermore, since methanol selectively permeates the zeolite composite 1, the concentration of methanol in the gas in contact with the catalyst 13 is reduced, and the production of methanol is promoted.

  Another end of the pipe 3 is connected to the permeated gas outlet b of the reactor, and transfers the methanol that has passed through the zeolite membrane of the zeolite membrane composite 1 to the permeated gas outlet b. Note that the zeolite membrane composite 1 may be directly connected to the permeated gas outlet b of the reactor without passing through the pipe 3.

In the present embodiment, the methanol selectively permeable membrane is bonded to the dense member by a bonding material having an inorganic oxide as a main component and a linear expansion coefficient of 30 × 10 ⁻⁷ / K or more and 90 × 10 ⁻⁷ / K or less. Is done.
What can be used as an inorganic adhesive can be suitably selected as an inorganic oxide.
Here, the inorganic adhesive is one that solidifies and adheres by a chemical reaction, and does not return to its original state even when heated. The inorganic adhesive is preferable because it can be generally bonded at 200 ° C. or lower, so that the zeolite membrane is hardly damaged.
Further, inorganic glass may be used. Examples of the inorganic oxide include alumina, titania, zirconia, silica, and magnesia. Examples of the inorganic glass include those containing SiO ₂ , Al ₂ O ₃ , ZnO, P ₂ O ₅ , Bi ₂ O ₃ , BaO, TiO ₂ , TeO ₂ , V ₂ O ₅ , B ₂ O ₃ , SnO, and the like as components. And a lead-free glass is preferable.
The main component means a component having the largest content (mass) of all components constituting the bonding material, and is usually 50% by mass or more of all components, and may be 70% by mass or more. It may be at least 90 mass%, and may be at least 90 mass%. A more preferable condition is that the softening point temperature is 550 ° C. or lower. Joining by glass is performed by setting the temperature to about 50 ° C. higher than the softening point temperature and then cooling. Therefore, if the softening point temperature exceeds 550 ° C., zeolite is damaged, which is not preferable. Such a phenomenon is because the separation membrane using the zeolite used in the present invention is a methanol permselective membrane that easily permeates large methanol as a molecular size and hardly permeates raw materials such as smaller carbon dioxide. When exposed to a temperature of 600 ° C. or more, the surface state of the zeolite changes, and the selectivity for methanol may be reduced.

Since the bonding material has a linear expansion coefficient of 30 × 10 ⁻⁷ / K or more and 90 × 10 ⁻⁷ / K or less, the adhesiveness between the methanol selectively permeable membrane and the dense member is enhanced, and good sealing properties and durability are achieved. Properties can be imparted. The linear expansion coefficient of the joining material is preferably 40 × 10 ⁻⁷ / K or more, and more preferably 80 × 10 ⁻⁷ / K or less.
The coefficient of linear expansion of the joining material generally depends on the coefficient of linear expansion of the main component, but can be adjusted by mixing other additives. In order to make the coefficient of linear expansion 30 × 10 ⁻⁷ / K or more and 90 × 10 ⁻⁷ / K or less, alumina, zirconia, silica, graphite, P ₂ O ₅ , Bi ₂ O ₃ , SnO or the like is mainly used. Good to use.

  As the bonding material, commercially available products may be used. For example, "TB3732" manufactured by Three Bond Co., "Aron Ceramic D", "Aron Ceramic E" manufactured by Toagosei Co., Ltd., "FP-74", "KP312E" manufactured by AGC, "KP312E", " “FP-67”, “BNL115BB”, “ASF-1094”, “ASF-1098”, “ASF-1109”, “Ceramabond 552” manufactured by Alemco, and the like can be used.

  The dense member to be joined to the methanol selective permeable membrane by the joining material is a member having denseness (confidentiality) such that a gas to be used for reaction or a reacted gas does not leak from the member. A cap for sealing the portion, a pipe connected to the end of the tubular member, and the like. The member is not particularly limited as long as it is a member having such denseness, and a metal is typically used. Examples of the metal here include SUS material made of stainless steel, ceramics such as alumina and zirconia, and alloys such as Kovar.

In the present embodiment, the dense member preferably has a linear expansion coefficient of 30 × 10 ⁻⁷ / K or more and 200 × 10 ⁻⁷ / K or less. When the linear expansion coefficient of the dense member is within the above range, the difference between the linear expansion coefficient of the bonding material and the linear expansion coefficient is small, and good sealing properties and durability can be maintained.
The difference in the coefficient of linear expansion between the joining material and the dense member is preferably 50 × 10 ⁻⁷ / K or less, more preferably 40 × 10 ⁻⁷ / K or less, and 30 × 10 ⁻⁷ / K. It is more preferably at most K. As described above, when the difference in the coefficient of linear expansion between the bonding material and the dense member is small, it is possible to suppress a bonding failure due to contraction of the material during sintering of the bonding material.

FIGS. 2 to 4 show examples in which the zeolite membrane composite and the dense member are joined via a joining material as a methanol-permeable membrane.
FIG. 2 is a schematic cross-sectional view showing an example in which the zeolite membrane composite and the dense member are joined via a joining material. The zeolite membrane composite 1 is joined to the pipe 3 via the joining material 4. The pipe 3 is joined so as to cover the zeolite membrane composite 1.
On the other hand, as shown in FIG. 3, the zeolite membrane composite 1 and the pipe 3 may be simply joined via a joining material. Since the joining material of the present embodiment has high sealing properties and durability, such joining is also possible.

  Further, as shown in FIG. 4, the zeolite membrane composite 1 and the reactor 10 can be directly bonded via the bonding material 4. In such an embodiment, since no piping is used, it is possible to reduce the cost of the manufacturing apparatus and reduce the risk of gas leakage due to the deterioration with time of the connection between members.

The methanol permselective membrane of the present embodiment is typically a zeolite membrane, but is not particularly limited as long as it can selectively permeate methanol. Various porous membranes, various MOFs (Metal Organic Framework) and the like can be used. It can also be used.
In one embodiment, the zeolite membrane is formed on a porous support member such as alumina and used as a zeolite membrane composite.

The main zeolite constituting the zeolite membrane preferably contains a zeolite having a pore structure of 12 or less oxygen rings and 6 or more oxygen rings.
Here, the value of n of the zeolite having an oxygen n-membered ring is such that the number of oxygen is the largest among pores formed of oxygen forming the zeolite skeleton and T element (element other than oxygen forming the skeleton). Show things. For example, when pores having a 12-membered oxygen ring and an 8-membered ring exist as in a MOR-type zeolite, it is regarded as a zeolite having a 12-membered oxygen ring.

The zeolite having a pore structure of 12 or less oxygen rings and 6 or more oxygen rings is a code defined by International Zeolite Association (IZA), for example, AEI, AEL, AFI, AFG, ANA, ATO, BEA, BRE, CAS, CDO, CHA, CON, DDR, DOH, EAB, EPI, ERI, ESV,
EUO, FAR, FAU, FER, FRA, HEU, GIS, GIU, GME, GOO, ITE, KFI, LEV, LIO, LOS, LTA, LTL, LTN, MAR, MEP, MER, MEL, MFI, MON, MOR, MSO, MTF, MTN, MTW, MWW, NON, NES, OFF, PAU, PHI, RHO, RTE, RTH, RUT, SGT, OD, STI, STT, TOL, TON, TSC, UFI, VNI, WEI, YUG, etc. Is raised. It is preferably one selected from these.

Since zeolite has poor flexibility, when it is formed into a film, it is formed while being supported on some substrate. The support is porous so that gas molecules can enter, and has, for example, a large number of fine pores connected in three dimensions.
The material constituting the support is preferably a chemically stable material that does not react with untreated gas and has excellent mechanical strength. Specifically, various types of alumina, silica, silica-alumina, and mullite , Oxide ceramics such as cordierite and zirconia, silicon carbide, carbon and glass can be used.
The shape of the support varies depending on the use of the zeolite membrane. In particular, the zeolite membrane on the cylindrical support has high strength against pressure from the outside, and is easily used in a batch process or a distribution process (recycle process). Is preferred.

  In the present embodiment, a zeolite membrane composite having a zeolite membrane formed on a support can be used. For the zeolite membrane composite, for example, a cylindrical support is prepared, and first, microcrystals of zeolite are supported in pores. A dipping method, a rubbing method, a suction method, an impregnation method, or the like can be used as a method for carrying the particles. The microcrystal serves as a nucleus when growing a crystal constituting the zeolite membrane, and is also referred to as a seed crystal. Hydrothermal synthesis can be used for the growth of zeolite, as in the case of zeolite synthesis.

  The thickness of the zeolite membrane in the zeolite membrane composite is not particularly limited, but is usually 0.1 μm or more, preferably 0.5 μm or more, and usually 50 μm or less, preferably 20 μm or less. When the film thickness is a certain value or more, sufficient denseness is obtained, and the selectivity of the film is kept high. By setting the film thickness to a certain value or less, a sufficient gas permeation amount can be obtained.

  In the present embodiment, a raw material gas containing at least hydrogen, carbon monoxide and / or carbon dioxide is reacted in a reactor in the presence of a catalyst to obtain methanol. The reaction conditions are not particularly limited, but the reaction temperature is preferably 200 ° C. or more and 300 ° C. or less. The reaction temperature means the temperature inside the reactor. By setting the reaction temperature to 200 ° C. or higher, the reaction rate increases, and the productivity increases. By setting the reaction temperature to 300 ° C. or lower, the chemical equilibrium of the reaction becomes advantageous for obtaining methanol, so that the conversion can be increased even if the performance of the membrane is somewhat inferior. Also, the allowable range of heat resistance required for the bonding agent is expanded.

The methanol obtained by the above reaction permeates through the methanol selective permeable membrane in the reactor, and the methanol is recovered from the permeated gas outlet of the reactor.
The pressure in the reactor at the time of permeating the produced methanol through the methanol selective permeable membrane, that is, the pressure (gauge pressure) on the gas supply side of the methanol selective permeable membrane in the reactor is preferably 1 MPaG or more, preferably 2 MPaG. It is more preferably at least 8 MPaG, more preferably at most 5 MPaG. By setting the pressure in an appropriate range, the equilibrium restriction of the reaction is reduced, and the reaction rate is improved, so that higher productivity is easily achieved. Further, it is possible to suppress an increase in the production cost of the reactor and an increase in the cost of increasing the pressure of the raw material gas due to the pressure being too high.
In the reaction vessel, the methanol partial pressure (absolute pressure) on the gas supply side of the methanol selective permeable membrane is preferably 0.1 MPaA or more, more preferably 0.2 MPaA or more, and 6 MPaA or less. And more preferably 5 MPaA or less. By setting the methanol partial pressure in this range, a sufficient amount of methanol permeating the membrane can be obtained, and the effect of the membrane is sufficiently exhibited. On the other hand, in this range, the joining can be performed easily and in a large amount without increasing the durability and sealing properties required for the joining portion more than necessary.
The gauge pressure in the reactor can be measured from a pressure gauge provided in the reactor. The absolute pressure of methanol in the reactor changes from upstream to downstream of the reactor.Here, the value calculated from the analysis result of the gas composition at the outlet of the reactor by gas chromatography and the gauge pressure is used as the value in the reactor. Methanol absolute pressure.

  Hereinafter, the present invention will be described in more detail with reference to Examples, but it goes without saying that the scope of the present invention is not limited to the embodiments shown in the following Examples.

<Example 1>
A porous alumina support to which seed crystals were previously attached was prepared using a composition 100SiO ₂ : 27.8N.
a ₂ O: 0.021 Al ₂ O ₃ : Dipped vertically in an inner tube made of Teflon (registered trademark) containing an aqueous reaction mixture of 4000 H ₂ O, the autoclave was sealed, and hydrothermal synthesis was performed at 180 ° C. for 12 hours. Was done. After elapse of a predetermined time, the mixture was allowed to cool to room temperature, and then the porous support-zeolite composite was taken out of the reaction mixture, washed, and dried at 120 ° C. for 4 hours or more to obtain a composite of the MFI zeolite and the porous alumina support. (Hereinafter, referred to as a membrane composite). The membrane complex was cut and used as needed.

A Kovar cap (linear expansion coefficient 52 × 10 ⁷ / K), a Kovar connection pipe (linear expansion coefficient 52 × 10 ⁷ / K), and a membrane composite are combined with a glass frit “BNL115BB (a linear expansion coefficient after firing) manufactured by AGC. 74 × 10 ⁷ / K), and baked in a muffle furnace at 500 ° C. for 30 minutes to join the membrane composite with the cap and the connection tube. The effective membrane length of the membrane composite after bonding was 34 mm.

<Manufacture of methanol>
The production of methanol was carried out using a SUS316L fixed bed reactor (internal volume 120 mL). A connecting pipe made of Kovar having the membrane composite bonded thereto was connected to the reactor using a Swagelok (R) union. Around the membrane composite, 75 g of a Cu-Zn-based composite oxide catalyst F07J (containing 49% by weight of CuO, 45% by weight of ZnO, and 5.6% by weight of Al ₂ O ₃ ) manufactured by Nikki Shokubai Kasei Co., Ltd. was charged, and the reactor was filled. Sealed.
Before the reaction, H ₂ diluted with N ₂ (H ₂ / N ₂ = 25/75, molar concentration) was passed through the reactor at 100 mL / min, and the catalyst was reduced at 300 ° C. and normal pressure for 6 hours. .
After the reduction of the catalyst was completed, the reactor was allowed to cool, and then the flow gas was switched to 332 mL / min of synthesis gas (raw gas: H ₂ /CO=66.9/33.1, molar ratio), and the reactor temperature was changed to 250. A reaction with membrane separation was carried out at a temperature of 3 ° C. and a pressure inside the reactor of 3 MPaG. Note that the partial pressure of methanol in the reactor was 0.55 MPaA.

The gas product was analyzed by on-line gas chromatography using N ₂ as an internal standard for both the membrane non-permeable component and the membrane permeable component. When the analysis result became stable, the CO _x conversion was calculated by the following equation (1).
Formula (1): CO _x conversion rate = 1− (non-permeate gas outlet CO flow rate + non-permeate gas outlet CO ₂ flow rate + permeate gas outlet CO flow rate + permeate gas outlet CO ₂ flow rate) / (raw material feed inlet CO flow rate + raw material) Feed inlet CO ₂ flow)
Further, the equilibrium CO _x conversion is determined from the equilibrium of the methanol synthesis reaction formulas shown in the formulas (2) and (3), and the CO _x conversion / equilibrium is used as an index indicating the rate of increase in the conversion from the equilibrium conversion. The CO _x conversion was determined.
Formula (2): 2H ₂ + CO ← → CH ₃ OH
Formula (3): 3H ₂ + CO ₂ ← → CH ₃ OH + H ₂ O

<Example 2>
Example 2 was performed in the same manner as in Example 1 except that the pressure in the reactor was 1.5 MPaG. The methanol partial pressure in the reactor was 0.33 MPaA.

<Example 3>
Example 3 was performed in the same manner as in Example 1 except that the temperature in the reactor was set to 230 ° C and the flow rate of the raw material gas was set to 83 mL / min. The methanol partial pressure in the reactor was 0.87 MPaA.

<Example 4>
Using a membrane composite of another lot synthesized under the same conditions as in Example 1, a glass frit "FP-74" (linear thermal expansion coefficient of 63 × 10 ⁷ / K after firing) was used for joining with a Kovar cap and a connecting pipe. )), The firing temperature was changed to 480 ° C., and the membrane composite was bonded to the cap and the connection pipe in the same manner as in Example 1. The effective membrane length of the membrane composite after bonding was 38 mm.
In the production of methanol, the amount of the catalyst was set to 75 g, and the flowing raw material gas was set to 147 mL / min of a synthesis gas containing CO ₂ (H ₂ / CO / CO ₂ = 69.5 / 23.2 / 7.3, molar ratio). Except for this, Example 4 was performed in the same manner as Example 1. The partial pressure of methanol in the reactor was 0.71 MPaA.

<Example 5>
The composition distribution to gas and _{H 2 / CO 2 = 75/} 25 ( molar ratio), except that the flow rate 131 mL / min the same manner as in Example 4, was that of Example 5. The partial pressure of methanol in the reactor was 0.22 MPaA.

<Example 6>
Using a membrane lot of another lot synthesized under the same conditions as in Example 1, an inorganic adhesive “Ceramar Bond 552 (linear expansion coefficient after firing: 77 × 10 ⁷ / K) ", and baked at 93 ° C. for 2 hours, and further baked at 260 ° C. for 2 hours to perform bonding. The effective membrane length of the membrane composite after bonding was 28 mm.
Methanol was produced in the same manner as in Example 1 except that the amount of the catalyst was 30 g and the flow rate of the flowing raw material gas was 321 mL / min. The methanol partial pressure in the reactor was 0.32 MPaA.

In Table 1, the CO _x conversion / equilibrium CO _x conversion exceeds 1 in all examples, and it can be seen that the methanol synthesis reaction is proceeding above the equilibrium. That is, according to the present invention, methanol can be efficiently produced at a conversion rate exceeding the equilibrium conversion rate.

<Reference Example 1>
As a joining material, a durability test of an O-ring that is often used for a mechanical seal was performed. As the O-ring, Kalrez (R) 6375, 7075, 0090, 7090 was used. The durability test was performed by encapsulating 5 mL of methanol and 5 mL of water and a bonding material in a 70-mL high-pressure container made of SUS316 or Hastelloy, replacing the inside of the container with N ₂ , and then heating at 250 ° C. for a predetermined time.
After the test, the durability of Kalrez (R) was evaluated by a hardness test (JIS K6253-2: 2012). Since the hardness of Kalrez (R) 6375 and 0090 decreased over time, it was determined that it could not be used at high temperature, high pressure and in the presence of methanol vapor. Further, Kalrez (R) 7075 and 7090 were significantly deformed during the test, making it impossible to carry out a hardness test, and similarly judged to be unusable at high temperature, high pressure and in the presence of methanol vapor.

<Reference Example 2>
As a bonding material, a durability test of a graphite packing often used for a mechanical seal was performed. As the graphite packing, TOMBO No. 2200-P, 2250 manufactured by Nichias was used. The durability test was performed in the same manner as in Reference Example 1.
After the test, graphite was separated from each other, so it was determined that the graphite could not be used at high temperature, high pressure and in the presence of methanol vapor.

<Reference Example 3>
A durability test was conducted on Alemco Bond 631, which is an epoxy adhesive for high vacuum, as a bonding material. Using a sample obtained by bonding an alumina plate and porous alumina with Alemco Bond 631, the same method as in Reference Example 1 was used.
After the test, the bonded alumina plate and the porous alumina were separated from each other. Therefore, it was judged that they could not be used at high temperature, high pressure and in the presence of methanol vapor.

  As described above, the bonding method shown in Reference Example was determined to be unusable under high temperature, high pressure and in the presence of methanol vapor, and thus could not be used for the production of methanol.

DESCRIPTION OF SYMBOLS 1 Zeolite membrane composite 2 Cap 3 Piping 4 Bonding material 10 Reactor 13 Catalyst

Claims (10)

A method for producing methanol, comprising reacting a raw material gas containing at least hydrogen, carbon monoxide and / or carbon dioxide in the presence of a catalyst in a reactor to obtain methanol,
In the reactor for performing the above reaction, the dense member was joined with a joining material containing an inorganic oxide as a main component and having a coefficient of linear expansion of 30 × 10 ⁻⁷ / K or more and 90 × 10 ⁻⁷ / K or less. A method for producing methanol, wherein a methanol permselective membrane is provided, and methanol produced by the reaction is extracted through the permselective membrane.   The method for producing methanol according to claim 1, wherein the methanol selective permeable membrane is a zeolite membrane.   The method for producing methanol according to claim 1, wherein the dense member is a metal.   The method for producing methanol according to any one of claims 1 to 3, wherein a partial pressure of methanol on the gas supply side of the methanol selective permeable membrane in the reactor is 0.1 MPa or more and 6 MPa or less.   The method for producing methanol according to any one of claims 1 to 4, wherein the temperature inside the reactor is 200C or more and 300C or less.   The method for producing methanol according to any one of claims 1 to 5, wherein a pressure on the gas supply side of the methanol selective permeable membrane in the reactor is 1 MPaG or more and 8 MPaG or less. The method for producing methanol according to any one of claims 1 to 6, wherein the linear expansion coefficient of the dense member is 30 × 10 ⁻⁷ / K or more and 200 × 10 ⁻⁷ / K or less.   The method for producing methanol according to any one of claims 1 to 7, wherein the dense member is Kovar.   The method for producing methanol according to any one of claims 1 to 8, wherein the inorganic oxide is an inorganic glass or an inorganic adhesive. A methanol production apparatus used in a production method for producing methanol by reacting a raw material gas containing at least hydrogen, carbon monoxide and / or carbon dioxide in the presence of a catalyst in a reactor,
In the reactor for performing the above reaction, the dense member was joined with a joining material containing an inorganic oxide as a main component and having a coefficient of linear expansion of 30 × 10 ⁻⁷ / K or more and 90 × 10 ⁻⁷ / K or less. An apparatus for producing methanol, having a structure in which a methanol permselective membrane is installed and methanol generated by the reaction permeates through the permselective membrane.