KR102658377B1 - Device for producing methacrylic acid - Google Patents

Abstract

[Problem] To provide a methacrylic acid production device that can simplify equipment.
[Solution means] The first reactor 10, the second reactors R ₁ to R _n (n represents an integer of 2 or more), the outlet of the first reactor 10 and the inlet of the second reactors R ₁ to R _n It is connected to a line (LA) that branches off the flow from the outlet of the first reactor 10 and supplies it to the inlet of each of the second reactors R ₁ to R _n , and to each of the second reactors R ₁ to R _n . It is connected to the outlet and has a line (LB) for joining the flows from the outlets of the second reactors R ₁ to R _n , the height A of the bottom of the second reactors R ₁ to R _n , and the height A of the bottom of the second reactors R ₁ to R _n. Each height H, the pipe in the flow path from the branch of the line LA to the inlet of the second reactor R ₁ to R _n , and the confluence of the line LB from the outlet of the second reactor R ₁ to R _n A methacrylic acid production device in which the piping in the flow path satisfies predetermined conditions.

Description

Methacrylic acid manufacturing device {DEVICE FOR PRODUCING METHACRYLIC ACID}

The present invention relates to a production apparatus for methacrylic acid.

Patent Document 1 describes a method for producing methacrylic acid.

International Publication No. 2008/145417

It is preferable that the production equipment used for the production of methacrylic acid has simple equipment. Therefore, the purpose of the present invention is to provide a methacrylic acid production device that can simplify equipment.

The apparatus for producing methacrylic acid of the present invention includes a first reactor for obtaining methacrolein from isobutylene and/or tert-butyl alcohol (hereinafter referred to as “TBA”) and oxygen, and methacrolein and oxygen. It is connected to a plurality of second reactors R ₁ to R _n (n represents an integer of 2 or more) for obtaining methacrylic acid by reaction, the outlet of the first reactor and the inlet of the second reactors R ₁ to R _n , and the first It is connected to a line (LA) that branches off the flow from the outlet of the reactor and supplies it to each inlet of the second reactors R ₁ to R _n , and to each outlet of the second reactors R ₁ to R _n , and It is provided with a line (LB) for joining the flow from the outlet of the second reactor R ₁ to R _n , and the height A ₁ to A _n of the bottom of each of the second reactors R ₁ to R _n satisfies equation (2). , the second reactors R ₁ ~R _n are installed, the height H ₁ ~H _n of each of the second reactors R ₁ ~R _n satisfies equation (3), and the second reactor R from the branch of the line LA The inner diameter D _1i to D _ni and the length L _1i to L _ni of the pipe in each flow path C1i to Cni from the inlet R _1i to R _ni of ₁ to R _n satisfy the conditions of equations (4a) and (4b). and the inner diameter D _1j to D _nj and the length L _1j of the pipe in each flow path C1j to Cnj from the outlet R _1j to R _nj of the second reactor R ₁ to R _n to the confluence of the line LB. L _nj satisfies the conditions of equations (5a) and (5b).

(A _max -A _min )/A _ave ≤0.02 … (2)

[A _max represents the maximum value among A ₁ to A _n , A _min represents the minimum value among A ₁ to A _n , and A _ave represents the average value of A ₁ to A _n .]

(H _max -H _min )/H _ave ≤0.02 … (3)

[H _max represents the maximum value among H ₁ to H _n , H _min represents the minimum value among H ₁ to H _n , and H _ave represents the average value of H ₁ to H _n .]

(D _max(i) /D _min(i) )≤1.025 … (4a)

[D _max(i) represents the maximum value among D _1i to D _ni , and D _min(i) represents the minimum value among D _1i to D _ni .]

(L _max(i) /L _min(i) )≤1.05 … (4b)

[L _max(i) represents the maximum value among L _1i to L _ni , and L _min(i) represents the minimum value among L _1i to L _ni .]

(D _max(j) /D _min(j) )≤1.025 … (5a)

[D _max(j) represents the maximum value among D _1j to D _nj , and D _min(j) represents the minimum value among D _1j to D _nj .]

(L _max(j) /L _min(j) )≤1.05 … (5b)

[L _max(j) represents the maximum value among L _1j to L _nj , and L _min(j) represents the minimum value among L _1j to L _nj .]

According to this methacrylic acid manufacturing apparatus, equipment can be simplified.

In the above methacrylic acid production device, when the same fluid is passed through the flow paths C1i to Cni at the same flow rate, the pressure loss ΔP _1i to ΔP _ni between the inlet and outlet in each flow path C1i to Cni is expressed by the formula When (1a) is satisfied and the same fluid is passed through the flow paths C1j to Cnj at the same flow rate, the pressure loss ΔP _1j to ΔP _nj between the inlet and outlet in each flow path C1j to Cnj is expressed in equation (1b). It is desirable to satisfy.

(ΔP _max(i) -ΔP _min(i) )/ΔP _ave(i) ≤0.10 … (1a)

[ΔP _max(i) represents the maximum value among ΔP _1i to ΔP _ni , ΔP _min(i) represents the minimum value among ΔP _1i to ΔP _ni , and ΔP _ave(i) represents the average value of ΔP _1i to ΔP _ni . represents.]

(ΔP _max(j) -ΔP _min(j) )/ΔP _ave(j) ≤0.10 … (lb)

[ΔP _max(j) represents the maximum value among ΔP _1j to ΔP _nj , ΔP _min(j) represents the minimum value among ΔP _1j to ΔP _nj , and ΔP _ave(j) represents the average value of ΔP _1j to ΔP _nj . represents.]

Thereby, the equipment can be further simplified.

According to the present invention, an apparatus for producing methacrylic acid that can simplify equipment is provided.

1 is a diagram showing an example of a methacrylic acid production apparatus of the present embodiment.

In this specification, isobutylene refers to 2-methylpropene.

First, with reference to FIG. 1, the methacrylic acid manufacturing apparatus 100 according to this embodiment will be described. 1 is a diagram showing an example of the methacrylic acid production apparatus of this embodiment.

This production device 100 is an example of a production device when the second reactor consists of two reactors. That is, the production apparatus 100 represents an embodiment in which n is 2 in a plurality of second reactors R ₁ to R _n (n represents an integer of 2 or more). In the description of the manufacturing device 100, “A ₁ ~A _n ”, “H ₁ ~H _n ”, “D _1i ~D _ni ”, “L _1i ~L _ni ”, “D _1j ~D _nj ”, The descriptions of “L _1j to L _nj ”, “ΔP _1i to ΔP _ni ” and “ΔP _1j to ΔP _nj ” are respectively “A ₁ and A ₂ ”, “H ₁ and H ₂ ”, and “D _1i and D _2i ”, “L _1i and L _2i ”, “D _1j and D _2j ”, “L _1j and L _2j ”, “ΔP _1i and ΔP _2i ”, and “ΔP _1j and ΔP _2j ”.

The manufacturing apparatus 100 is mainly equipped with a first reactor 10, a second reactor 20, a separation means 60, and lines LA and LB. Line LA is provided with a gas mixer 50b. The second reactor 20 consists of reactors R ₁ and R ₂ .

A supply source S0 of a gas containing isobutylene and/or TBA and oxygen is connected to the inlet 10i of the first reactor 10 via a line L10.

The first reactor 10 is a reactor for obtaining methacrolein from isobutylene and/or TBA and oxygen.

The first reactor 10 is preferably a reactor filled with a catalyst in a container. The first reactor 10 may be a fixed bed reaction device in which a container is filled with a catalyst. There are no restrictions on the direction of flow, and it can be either up flow or down flow. Examples of catalysts used in the reaction to synthesize methacrolein from isobutylene and/or TBA and oxygen are metal oxides containing molybdenum and bismuth.

When methacrolein is obtained from isobutylene and oxygen, isobutylene and oxygen react, thereby producing methacrolein. It is also possible to use TBA instead of isobutylene. When methacrolein is obtained from TBA and oxygen, it is thought that isobutylene is produced through a dehydration reaction of TBA, and methacrolein is produced by the reaction between the produced isobutylene and oxygen. The reason why TBA can be used instead of isobutylene is thought to be that, in the first reactor 10, the oxidation reaction of isobutylene is rate-limiting. Isobutylene and TBA can also be used together.

The outlet 10j of the first reactor 10 and the inlet R _1i and R _2i of the second reactor 20 are connected by a line LA. The inlets (R _1i and R _2i ) of the second reactor 20 are the inlets of the reactors (R ₁ and R ₂ ), respectively. The line LA is a line that branches the flow from the outlet 10j of the first reactor 10 and supplies it to the respective inlets of the reactors R ₁ and R ₂ .

A line L22 is connected to the inlet 50b _m of the gas mixer 50b of the line LA. The line L22 is a line connecting the line LA and the oxygen source S1, and a compressor 55 is provided in a part of the line.

The second reactor 20 is a reactor for obtaining methacrylic acid by reacting methacrolein and oxygen. The reactor constituting the second reactor 20 is preferably a reactor filled with a catalyst in a container. The reactor constituting the second reactor 20 may be a fixed bed reaction device in which a container is filled with a catalyst. The fixed bed reaction device may be, for example, a device in which each tube of a shell-and-tube heat exchanger is filled with solid particles including catalyst particles and, if necessary, inert particles. There is no particular limitation on the direction of flow, and it may be up flow or down flow. An example of a catalyst used in the reaction to synthesize methacrylic acid from methacrolein and oxygen is a heteropoly acid compound containing phosphorus and molybdenum.

The outlet (R _1j and R _2j ) of the second reactor 20 and the inlet 60i of the separation means 60 are connected by a line LB. The outlets (R _1j and R _2j ) of the second reactor 20 are the outlets of the reactors (R ₁ and R ₂ ), respectively. The line LB is a line that merges the flows from the outlets of the reactors R ₁ and R ₂ and supplies them to the separation means 60 .

The reactors R ₁ and R ₂ are installed so that the heights A ₁ and A ₂ of the respective bottoms satisfy equation (2). The heights H ₁ and H ₂ of the reactors (R ₁ and R ₂ ), respectively, satisfy equation (3). Here, height means the length in the vertical direction. The height A of the bottom of the reactor refers to the height from the ground surface to the bottom of the reactor, and the height H of the reactor refers to the height of the reactor itself.

(A _max -A _min )/A _ave ≤0.02 … (2)

[A _max represents the maximum value among A ₁ to A _n , A _min represents the minimum value among A ₁ to A _n , and A _ave represents the average value of A ₁ to A _n .]

(H _max -H _min )/H _ave ≤0.02 … (3)

[H _max represents the maximum value among H ₁ to H _n , H _min represents the minimum value among H ₁ to H _n , and H _ave represents the average value of H ₁ to H _n .]

_Ave may be, for example, 1 to 15 m, 2 to 12 m, or 4 to 10 m.

H _ave may be, for example, 1 to 12 m, 2 to 10 m, or 4 to 8 m.

The inner diameter D _1i and length L _1i of the pipe in the flow path C1i from the branch Xa of the line LA to the inlet R _1i of the reactor R ₁ and the branch part of the line LA ( The inner diameter D _2i and length _{L 2i of} the pipe in the flow path C2i from Xa) to the inlet R _2i of the reactor R 2 satisfy the conditions of equations (4a) and (4b).

(D _max(i) /D _min(i) )≤1.025 … (4a)

[D _max(i) represents the maximum value among D _1i to D _ni , and D _min(i) represents the minimum value among D _1i to D _ni .]

(L _max(i) /L _min(i) )≤1.05 … (4b)

[L _max(i) represents the maximum value among L _1i to L _ni , and L _min(i) represents the minimum value among L _1i to L _ni .]

The inner diameter D _1j and length L _1j of the pipe in the flow path C1j from the outlet R _1j of the reactor R ₁ to the confluence Xb of the line LB, and the outlet of the reactor R ₂ ( The inner diameter D _2j and the length L _2j of the pipe in the flow path C2j from R _2j ) to the confluence Xb of the line LB satisfy the conditions of equations (5a) and (5b).

(D _max(j) /D _min(j) )≤1.025 … (5a)

[D _max(j) represents the maximum value among D _1j to D _nj , and D _min(j) represents the minimum value among D _1j to D _nj .]

(L _max(j) /L _min(j) )≤1.05 … (5b)

[L _max(j) represents the maximum value among L _1j to L _nj , and L _min(j) represents the minimum value among L _1j to L _nj .]

In this specification, the inner diameter of the pipe means the average value of the longitudinal integral of the inner diameter of the pipe. Additionally, the length of the pipe means the length of the central axis of the pipe.

D _max(i) may be, for example, 200 to 1800 mm, 400 to 1500 mm, or 600 to 1300 mm.

L _max(i) may be, for example, 1 to 40 m, 5 to 35 m, or 10 to 30 m.

D _max(j) may be, for example, 200 to 1800 mm, 400 to 1500 mm, or 600 to 1300 mm.

L _max(j) may be, for example, 1 to 40 m, 5 to 35 m, or 10 to 30 m.

From the viewpoint of further simplifying the equipment, the manufacturing apparatus 100 has a pressure loss ΔP _1i between the inlet and outlet of the flow path C1i when the same fluid is passed through the flow paths C1i and C2i at the same flow rate. and the pressure loss ΔP _2i between the inlet and outlet in the flow path C2i satisfies equation (1a), and when the same fluid is passed through the flow paths C1j and C2j at the same flow rate, the pressure loss ΔP 2i in the flow path C2i is It is preferable that the pressure loss ΔP _1j between the inlet and the outlet in the channel C2j and the pressure loss ΔP _2j between the inlet and the outlet in the flow path C2j satisfy equation (1b). Here, the same fluid means a fluid with the same composition, temperature, and pressure.

(ΔP _max(i) -ΔP _min(i) )/ΔP _ave(i) ≤0.10 … (1a)

[ΔP _max(i) represents the maximum value among ΔP _1i to ΔP _ni , ΔP _min(i) represents the minimum value among ΔP _1i to ΔP _ni , and ΔP _ave(i) represents the average value of ΔP _1i to ΔP _ni . represents.]

(ΔP _max(j) -ΔP _min(j) )/ΔP _ave(j) ≤0.10 … (lb)

[ΔP _max(j) represents the maximum value among ΔP _1j to ΔP _nj , ΔP _min(j) represents the minimum value among ΔP _1j to ΔP _nj , and ΔP _ave(j) represents the average value of ΔP _1j to ΔP _nj . represents.]

The flow path C1i from the branch Xa to the inlet R _1i of the reactor R ₁ and the flow path C2i from the branch Xa to the inlet R _2i of the reactor R ₂ are, In its shape, it may be approximately congruent. As a result, the manufacturing apparatus 100 tends to easily satisfy the range of equation (1a). The flow path C1j from the outlet R _1j of the reactor R ₁ to the confluence part Xb and the flow path C2j from the outlet R _2j of the reactor R ₂ to the confluence part Xb are, In its shape, it may be approximately congruent. As a result, the manufacturing apparatus 100 tends to easily satisfy the range of equation (1b). The shape of the piping included between the branch portion

The separation means 60 separates a stream F35 containing carbon monoxide, carbon dioxide, nitrogen, argon, light components and oxygen from the first outlet, and a stream F31 containing methacrylic acid and heavy components from the second outlet. , the stream F23 containing methacrolein is discharged from the third outlet, respectively. A line L35 is connected to the first outlet, a line L31 is connected to the second outlet, and a line L23 is connected to the third outlet.

Line L23 is connected to line LA.

Examples of the separation means 60 include distillation columns, extraction columns, absorption columns, and combinations thereof. When the separation means 60 consists of one distillation column, it is preferable that the line L35 is provided at the top of the distillation column, the line L31 is provided at the bottom of the distillation column, and the line L23 is provided on the side of the distillation column. .

Next, a method for producing methacrylic acid according to the present embodiment will be described.

(source)

Prepare a stream containing isobutylene and/or TBA and oxygen (F10) as a source of gas containing isobutylene and/or TBA and oxygen (S0).

Stream F10 may contain components other than isobutylene, TBA, and oxygen. Components other than isobutylene, TBA, and oxygen include, for example, C5 olefins such as isoprene, isobutane, 1-butene, 2-butene (cis, trans), propane, propylene, n-butane, and methyl-tert. - Examples include butyl ether, methanol, dimethyl ether, butadiene, propadiene, diisobutylene, nitrogen, carbon dioxide, carbon monoxide, water, and argon.

The concentration of isobutylene and/or TBA in the flow (F10) is the sum of the concentrations of isobutylene and TBA, for example, 1% by mass or more, 2% by mass or more, or 4% by mass or more. The total concentration of isobutylene and TBA in stream F10 is, for example, 21 mass% or less, 19 mass% or less, or 17 mass% or less. The total concentration of isobutylene and TBA in the stream (F10) is preferably 1 to 21 mass%, more preferably 2 to 19 mass%, and still more preferably 4 to 17 mass%.

The oxygen concentration in the flow F10 is, for example, 7 mass% or more, 8 mass% or more, or 10 mass% or more. The oxygen concentration in the flow F10 is, for example, 24 mass% or less, 23 mass% or less, or 21 mass% or less. The oxygen concentration in the flow (F10) is preferably 7 to 24 mass%, more preferably 8 to 23 mass%, and still more preferably 10 to 21 mass%.

Additionally, a flow (F22) containing oxygen as the oxygen source (S1) is prepared.

The concentration of oxygen in the flow F22 is, for example, 15% by mass or more. The concentration of oxygen in the flow (F22) is preferably 16 mass% or more, more preferably 17 mass% or more, and even more preferably 20 mass% or more. The upper limit of the oxygen concentration in the flow F22 can be, for example, 35% by mass. The concentration of oxygen in the flow F22 may be, for example, 30 mass% or less or 25 mass% or less. The oxygen concentration in the flow (F22) is preferably 16 to 35 mass%, more preferably 17 to 30 mass%, and still more preferably 18 to 25 mass%.

(reaction process)

The stream F10 is supplied to the first reactor 10, and the isobutylene and oxygen in the stream F10 are reacted in the first reactor 10. The stream (F11) containing methacrolein obtained by the reaction of isobutylene and oxygen is discharged from the line (LA).

The reaction temperature of the first reactor 10 can be 300 to 400°C. The reaction pressure of the first reactor 10 can be 0.004 to 0.6 MPaG (gauge pressure).

The stream F11 discharged from the first reactor 10 is mixed with the stream F23 containing methacrolein through the line L23, and the stream containing oxygen is mixed through the line L22 ( F22) is mixed. As a result, the obtained flow F21 is supplied to each reactor R ₁ and R ₂ of the second reactor 20 through the line LA.

The concentration of methacrolein in the stream (F23) is preferably 0.1 mass% or more, more preferably 3 mass% or more, and even more preferably 7 mass% or more. The concentration of methacrolein in the stream (F23) is preferably 32 mass% or less, more preferably 23 mass% or less, and still more preferably 16 mass% or less. The concentration of methacrolein in the flow (F23) may be 0.1 to 32 mass%, 3 to 23 mass%, or 7 to 16 mass%. Stream F23 may contain, for example, nitrogen, water, and carbon dioxide as components other than methacrolein.

In the second reactor 20, methacrylic acid is obtained by reacting methacrolein and oxygen, and a stream F30 containing methacrylic acid is discharged through the line LB.

Stream (F30) usually contains unreacted methacrolein. Stream F30 may contain components other than methacrylic acid and methacrolein. These ingredients include acrylic acid, acrolein, nitrogen, argon, oxygen, water, carbon monoxide, carbon dioxide, acetaldehyde, propionaldehyde, terephthalic acid, maleic acid, fumaric acid, diacetyl, isophthalic acid, isobutyric acid, methylfurfural, acetic acid, propionic acid, etc. can be mentioned.

The reaction temperature of the second reactor 20 can be 200 to 350°C. The reaction pressure in the second reactor 20 is, for example, 0.01 to 0.3 MPaG.

(Separation process and recycling process)

The flow F30 is supplied to the separation means 60 via the line LB. The streams are separated in the separation means 60 to produce a stream F35 containing carbon monoxide, carbon dioxide, nitrogen, argon, light components and oxygen from line L35, and a stream F35 containing methacrylic acid and heavy components from line L31. The flow F31 containing methacrolein and the flow F23 containing methacrolein are discharged from line L23, respectively.

The flow F23 containing methacrolein is joined to the flow F11 through the line L23.

The methacrylic acid production apparatus 100 includes a first reactor 10 for obtaining methacrolein from isobutylene and/or TBA and oxygen, and a plurality of reactors for producing methacrylic acid by reacting methacrolein and oxygen. Connected to the second reactor 20 (R ₁ and R ₂ ), the outlet 10j of the first reactor 10 and the inlet of the second reactor 20 (R ₁ and R ₂ ), the first reactor 10 ) and a line (LA) that branches off the flow from the outlet (10j) and supplies it to each inlet of the second reactor (20) (R ₁ and R ₂ ), and the second reactor (20) (R ₁ and R ₂ ) is connected to each outlet of the second reactor 20 (R ₁ and R ₂ ), and has a line (LB) for joining the flows from the outlets of the second reactor 20 (R 1 and R 2 ), and at the bottom of each of the reactors (R ₁ and R ₂ ). The heights A ₁ and A ₂ are installed to satisfy equation (2), the heights H ₁ and H ₂ of the reactors (R ₁ and R ₂ ) respectively satisfy equation (3), and the branch of the line (LA) The inner diameters D _1i and D _2i and the lengths L _1i and L _2i of the pipes in each passage (C1i and C2i) from (Xa) to the inlet (R _1i and R _2i ) of the reactor (R ₁ and R ₂ ) are The conditions of equations (4a) and (4b) are satisfied, and each flow path (C1j) from the outlet (R _1j and R _2j ) of the reactor (R ₁ and R ₂ ) to the confluence (Xb) of the line (LB) and C2j), the inner diameters D _1j and D _2j and the lengths L _1j and L _2j of the pipe satisfy the conditions of equations (5a) and (5b). As a result, it is easy to spread the fluid evenly in the reactors R ₁ and R ₂ even without installing a valve in the line LA, so the equipment can be simplified and long-term operation can be achieved even without particularly complicated operations. I think you can drive stably. In addition, since a valve or the like is not necessarily required at the above-mentioned position, it is thought that clogging of the piping at a complex-shaped portion such as a valve can be prevented. In addition, the methacrylic acid production apparatus 100 has a plurality of second reactors, so there is a tendency to easily charge the second reactor with a greater amount of catalyst than necessary. By charging the second reactor with more catalyst than necessary, it is thought that it is easy to maintain the productivity of the second reactor even if, for example, the catalyst activity of the second reactor decreases before that of the first reactor.

Since the device of this embodiment is excellent in continuous operation, it is thought that it is possible to reduce raw materials and energy during long-term operation.

The present invention is not limited to the above embodiments, and various modifications are possible.

For example, separation and purification means such as a distillation column or an extraction column may be added to each line.

The gas mixer 50b can also be omitted. In this case, the line L22 can be directly connected to the pipe of the line L21.

Line (L23) may or may not be present. In the methacrylic acid production apparatus 100, the line L23 is connected to the separation means 60, but the line L23 does not need to be connected to the separation means 60. That is, the flow supplied to line LA via line L23 does not have to be the flow recycled from separation means 60.

The second reactor may be composed of three or more reactors. That is, in the plurality of second reactors R ₁ to R _n , n may be 3 or more. In this case, at the branch of the line LA, it branches into n flow paths, and at the confluence of the line LB, n flow paths join. In addition, the reactors R ₁ to R _n are installed so that the heights of each bottom A ₁ to A _n satisfy equation (2), and the heights H ₁ to H _n satisfy equation (3), and the line The inner diameter D _1i to D _ni and the length L _1i to L _ni of the pipes in each flow path C1i to Cni from the branch of (LA) to the inlet R _1i to R _ni of the reactor R ₁ to R _n are expressed in equation (4a) ) and the conditions of equation (4b) are satisfied, and the inner diameter D _1j of the pipe in each flow path C1j to Cnj from the outlet R _1j to R nj of the reactor R ₁ to R _n to the confluence of the line _LB A device such that D _nj and length L _1j to L _nj satisfy the conditions of equations (5a) and (5b) can be used.

Additionally, even in the case where n is 3 or more, when the same fluid is passed through the flow paths C1i to Cni at the same flow rate, the pressure loss ΔP _1i to ΔP _ni between the inlet and outlet in each flow path C1i to Cni is expressed by the equation When (1a) is satisfied and the same fluid is passed through the flow paths C1j to Cnj at the same flow rate, the pressure loss ΔP _1j to ΔP _nj between the inlet and outlet in each flow path C1j to Cnj is expressed in equation (1b). It is desirable to satisfy.

10… first reactor
20… second reactor
50b… gas mixer
60… means of separation
100… Methacrylic acid manufacturing device

Claims (2)

a first reactor for obtaining methacrolein from isobutylene and/or tert-butyl alcohol and oxygen;
A plurality of second reactors R ₁ to R _n (n represents an integer of 2 or more) for producing methacrylic acid by reacting methacrolein and oxygen;
A line (LA) connected to the outlet of the first reactor and the inlet of the second reactor R ₁ to R _n , and branches the flow from the outlet of the first reactor and supplies it to each inlet of the second reactor R ₁ to R _n . class,
It is connected to each outlet of the second reactors R ₁ to R _n and has a line LB for joining the flows from the outlets of the second reactors R ₁ to R _n ,
The second reactors R ₁ to R _n are installed so that the height A ₁ to A _n of the bottom of each of the second reactors R ₁ to R _n satisfies equation (2),
The height H ₁ ~H _n of each of the second reactors R ₁ ~R _n satisfies equation (3),
The inner diameter D _1i to D _ni and the length L _1i to L _ni of the pipes in each flow path C1i to Cni from the branch of the line LA to the inlet R _1i to R _ni of the second reactor R ₁ to R _n are Satisfies the conditions of equations (4a) and (4b),
The inner diameter D _1j to D _nj and the length L _1j to L _nj of the pipes in each flow path C1j to Cnj from the outlet R _1j to R _nj of the second reactor R ₁ to R _n to the confluence of the line LB are A production device for methacrylic acid that satisfies the conditions of Formula (5a) and Formula (5b).
(A _max -A _min )/A _ave ≤0.02 … (2)
[A _max represents the maximum value among A ₁ to A _n , A _min represents the minimum value among A ₁ to A _n , and A _ave represents the average value of A ₁ to A _n .]
(H _max -H _min )/H _ave ≤0.02 … (3)
[H _max represents the maximum value among H ₁ to H _n , H _min represents the minimum value among H ₁ to H _n , and H _ave represents the average value of H ₁ to H _n .]
(D _max(i) /D _min(i) )≤1.025 … (4a)
[D _max(i) represents the maximum value among D _1i to D _ni , and D _min(i) represents the minimum value among D _1i to D _ni .]
(L _max(i) /L _min(i) )≤1.05 … (4b)
[L _max(i) represents the maximum value among L _1i to L _ni , and L _min(i) represents the minimum value among L _1i to L _ni .]
(D _max(j) /D _min(j) )≤1.025 … (5a)
[D _max(j) represents the maximum value among D _1j to D _nj , and D _min(j) represents the minimum value among D _1j to D _nj .]
(L _max(j) /L _min(j) )≤1.05 … (5b)
[L _max(j) represents the maximum value among L _1j to L _nj , and L _min(j) represents the minimum value among L _1j to L _nj .] According to claim 1,
When the same fluid is passed through the flow paths C1i to Cni at the same flow rate, the pressure loss ΔP _1i to ΔP _ni between the inlet and outlet in each flow path C1i to Cni satisfies equation (1a),
When the same fluid is passed through flow paths C1j to Cnj at the same flow rate, the pressure loss ΔP _1j to ΔP _nj between the inlet and outlet in each flow path C1j to Cnj satisfies equation (1b). Methacrylic acid manufacturing equipment.
(ΔP _max(i) -ΔP _min(i) )/ΔP _ave(i) ≤0.10 … (1a)
[ΔP _max(i) represents the maximum value among ΔP _1i to ΔP _ni , ΔP _min(i) represents the minimum value among ΔP _1i to ΔP _ni , and ΔP _ave(i) represents the average value of ΔP _1i to ΔP _ni . represents.]
(ΔP _max(j) -ΔP _min(j) )/ΔP _ave(j) ≤0.10 … (lb)
[ΔP _max(j) represents the maximum value among ΔP _1j to ΔP _nj , ΔP _min(j) represents the minimum value among ΔP _1j to ΔP _nj , and ΔP _ave(j) represents the average value of ΔP _1j to ΔP _nj . represents.]