KR20200056315A - Device for producing methacrylic acid - Google Patents

Abstract

The present invention provides an apparatus for producing methacrylic acid which can simplify facilities. The apparatus for producing methacrylic acid includes: a first reactor (10); second reactors R_1-R_n (wherein n is an integer of 2 or more); a line (LA) linked to the outlet of the first reactor (10) and the inlets of the second reactors R_1-R_n, and dividing the flow discharged from the outlet of the first reactor (10) to supply the divided flows to each of the inlets of the second reactors R_1-R_n; and a line (LB) linked to each of the outlets of the second reactors R_1-R_n to combine the flows discharged from the outlets of the second reactors R_1-R_n. In the apparatus, the height A of the bottom of each of the second reactors R_1-R_n, the height H of the second reactors R_1-R_n, piping in the flow path from the intersection of the line (LA) to the inlets of the second reactors R_1-R_n, and the piping in the flow path from the outlets of the second reactors R_1-R to the confluence of the line (LB) satisfy predetermined conditions.

Description

Manufacturing device for methacrylic acid {DEVICE FOR PRODUCING METHACRYLIC ACID}

The present invention relates to an apparatus for producing methacrylic acid.

Patent Document 1 describes a method for producing methacrylic acid.

International Publication No. 2008/145417

It is preferable that the manufacturing apparatus used for the production of methacrylic acid has a simple facility. Therefore, it is an object of the present invention to provide an apparatus for producing methacrylic acid which can simplify equipment.

The methacrylic acid production apparatus of the present invention comprises 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 (where n represents an integer of 2 or more) to obtain methacrylic acid by reaction, and to the outlet of the first reactor and the inlets of the second reactors R ₁ to R _n , the first to branch the flow (流) out from the outlet of the reactor, the second reaction vessel R ₁ ~ R _n each line to be supplied to the inlet (LA) of the second is connected to each outlet of the reactor R ₁ ~ R _n, a 2 so as to provided with a reactor R ₁ ~ line (LB) that join the out flow from the outlet of the R _n, and the second reactor, _{R 1 ~ R n 1 ~ a} n a respective bottom portion height meets the formula (2) , The second reactor R ₁ ~ R _n is installed, the height H ₁ ~ H _n of each of the second reactors R ₁ ~ R _n meets the formula (3), and the second reactor R from the branch of the line LA The inner diameters D _1i to D _ni and the lengths L _1i to L _ni of the pipes in the respective flow paths C1i to Cni from the inlets R _1i to R _ni of ₁ to R _n satisfy the conditions of equations (4a) and (4b). Satisfying, the inner diameters D _1j ~ D _nj and the length L _1j ~ of the pipes in each flow path C1j ~ Cnj from the outlets R _1j ~ R _nj of the second reactors R ₁ ~ 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 such an apparatus for producing methacrylic acid, the equipment can be simplified.

In the methacrylic acid production apparatus, 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 the outlet in each flow path C1i to Cni is 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 the outlet in each flow path C1j to Cnj is expressed by equation (1b). It is preferable 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 Indicates.]

(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 Indicates.]

Thereby, the facility can be further simplified.

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

1 is a view showing an example of an apparatus for producing methacrylic acid of the present embodiment.

In this specification, isobutylene refers to 2-methylpropene.

First, with reference to FIG. 1, the methacrylic acid manufacturing apparatus 100 which concerns on this embodiment is demonstrated. 1 is a view showing an example of an apparatus for producing methacrylic acid of the present embodiment.

The manufacturing apparatus 100 is an example of a manufacturing apparatus when the second reactor is composed of two reactors. That is, the manufacturing apparatus 100 shows one aspect when 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 apparatus 100, "A ₁ ~ A _n ", "H ₁ ~ H _n ", "D _1i ~ D _ni ", "L _1i ~ L _ni ", "D _1j ~ D _nj ", The descriptions of ` <sub>`</sub> L _1j ~ L _nj '', ` <sub>`</sub> ΔP _1i ~ ΔP _ni '' and ` <sub>`</sub> ΔP _1j ~ ΔP _nj '' are ` <sub>`</sub> A ₁ and A ₂ '', _{``</sub> H <sub>1</sub> and H <sub>2</sub> '', <sub>``} D _1i and D _{2i, respectively.} , "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 mainly includes a first reactor 10, a second reactor 20, a separation means 60, and lines LA and LB. Line LA has a gas mixer 50b. The second reactor 20 is composed of reactors R ₁ and R ₂ .

A 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.

It is preferable that the 1st reactor 10 is a reactor filled with a catalyst in a container. The first reactor 10 may be a fixed bed reaction apparatus filled with a catalyst in a container. There is no restriction on the direction of the flow, and it may be either upflow or downflow. Examples of catalysts used in the reaction for synthesizing 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 by dehydration reaction of TBA, and metachlorolane is produced by reaction of the produced isobutylene and oxygen. It is thought that the reason why TBA can be used instead of isobutylene is that in the first reactor 10, the oxidation reaction of isobutylene is at a rate. Isobutylene and TBA can also be used together.

The outlet 10j of the first reactor 10 and the inlets 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 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 each inlet of the reactors R ₁ and R ₂ .

The 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 supply 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 vessel. The reactor constituting the second reactor 20 may be a fixed bed reaction device in which a catalyst is filled in a container. The stationary phase reaction device may be, for example, a device in which catalyst particles and, if necessary, solid particles containing inert particles are filled in each tube of the multi-tube heat exchanger. The direction of the flow is not particularly limited, and may be an up flow or a down flow. Examples of catalysts used in the reaction for synthesizing methacrylic acid from methacrolein and oxygen are heteropoly acid compounds containing phosphorus and molybdenum.

The outlets R _1j and R _2j of the second reactor 20 and the inlet 60i of the separating means 60 are connected by a line LB. The outlets R _1j and R _2j of the second reactor 20 are outlets of the reactors R ₁ and R ₂ , respectively. The line LB is a line that joins 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 such that the heights A ₁ and A ₂ of each bottom portion satisfy equation (2). The heights H ₁ and H ₂ of each of the reactors R ₁ and R ₂ satisfy equation (3). Here, the height means the length in the vertical direction. The height A of the bottom of the reactor means the height from the ground surface to the bottom of the reactor, and the height H of the reactor means 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 .]

A _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 the length L _1i of the pipe in the flow path C1i from the branch part 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 the 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 the formulas (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 the length L _1j of the pipe in the flow path C1j from the outlet R _1j of the reactor R _{1 to} the confluence part 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 portion 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 integral in the longitudinal direction in the inner diameter of the pipe. In addition, 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 1 to 40 m, for example, 5 to 35 m, or 10 to 30 m.

The manufacturing apparatus 100 is a pressure loss ΔP _1i between the inlet and the outlet in the flow path C1i when the same fluid is passed through the flow paths C1i and C2i at the same flow rate from the viewpoint of simpler simplification of the equipment. And when the pressure loss ΔP _2i between the inlet and the outlet in the flow path C2i satisfies Expression (1a) and passes the same fluid through the flow paths C1j and C2j at the same flow rate, it flows into the flow path C1j. It is preferable that the pressure loss ΔP _1j between the inlet and the outlet in and the pressure loss ΔP _2j between the inlet and the outlet in the flow path C2j satisfies Expression (1b). Here, the same fluid means a fluid having 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 Indicates.]

(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 Indicates.]

The flow path C1i from the branch portion Xa to the inlet R _1i of the reactor R ₁ and the flow path C2i from the branch portion Xa to the inlet R _2i of the reactor R ₂ are: In the shape, it may be approximately congruent. Thereby, the manufacturing apparatus 100 tends to be easy to satisfy the range of Expression (1a). The flow path C1j from the outlet R _1j of the reactor R ₁ to the confluence section Xb and the flow path C2j from the outlet R _2j of the reactor R ₂ to the confluence section Xb are: In the shape, it may be approximately congruent. Thereby, the manufacturing apparatus 100 tends to be easy to satisfy the range of equation (1b). The shape of the pipe included between the branching part Xa and the joining part Xb may be substantially symmetrical with respect to any one of the surfaces including the line connecting the branching part Xa and the joining part Xb.

The separating means 60 comprises a flow (F35) comprising carbon monoxide, carbon dioxide, nitrogen, argon, light components and oxygen from the first outlet, and a flow (F31) comprising methacrylic acid and heavy components from the second outlet. , The flow (F23) containing metacrolein 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.

The line L23 is connected to the line LA.

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

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

(Source)

A stream (F10) comprising isobutylene and / or TBA and oxygen as a source (S0) of gas containing isobutylene and / or TBA and oxygen is prepared.

Flow (F10) may contain components other than isobutylene, TBA, and oxygen. As components other than isobutylene, TBA and oxygen, for example, C5 olefins such as isoprene, isobutane, 1-butene, 2-butene (cis, trans), propane, propylene, n-butane, methyl-tert -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 the flow (F10) is, for example, 21% by mass or less, 19% by mass or less, or 17% by mass or less. The sum of the concentrations of isobutylene and TBA in the flow (F10) is preferably 1 to 21% by mass, more preferably 2 to 19% by mass, and still more preferably 4 to 17% by mass.

The oxygen concentration in the flow F10 is, for example, 7% by mass or more, 8% by mass or more, or 10% by 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 even more preferably 10 to 21 mass%.

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

(Reaction process)

The flow (F10) is supplied to the first reactor (10), and isobutylene and oxygen in the flow (F10) are reacted in the first reactor (10). The flow (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).

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

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

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

The flow F30 usually contains unreacted methacrolein. The flow (F30) may contain components other than methacrylic acid and methacrolein. As such components, 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 heard.

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 provided to the separating means 60 via the line LB. Separating means 60 separates the flow, from line L35 a flow (F35) comprising carbon monoxide, carbon dioxide, nitrogen, argon, light components and oxygen, including methacrylic acid and heavy components from line L31 The flow (F31) to be performed is discharged from the line (L23), the flow (F23) containing methacrolein, respectively.

The flow F23 containing methacrolein joins the flow F11 via 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 agents for obtaining methacrylic acid by reacting methacrolein and oxygen. 2 reactor 20 (R ₁ and R ₂ ), the first reactor 10 is connected to the outlet 10j and the inlet of the second reactor 20 (R ₁ and R ₂ ), the first reactor 10 ) Branching the flow from the outlet (10j) of the second reactor (20) (R ₁ and R ₂ ) to the line (LA) for supplying to each inlet, and the second reactor 20 (R ₁ and R ₂₎ ) Is connected to each outlet, and has a line (LB) for joining the flow from the outlet of the second reactor 20 (R ₁ and R ₂ ), the bottom portion of each of the reactor (R ₁ and R ₂ ) The heights A ₁ and A ₂ are installed to meet equation (2), the heights H ₁ and H ₂ of each of the reactors (R ₁ and R ₂ ) meet 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 the respective flow paths C1i and C2i from (Xa) to the inlets R _1i and R _2i of the reactors R ₁ and R ₂ are The flow paths C1j from the outlets R _1j and R _2j of the reactors R ₁ and R _{2 to} the confluence section Xb of the line LB satisfy the conditions of equations (4a) and (4b), And the inner diameters D _1j and D _2j and the lengths L _1j and L _2j of the pipe in C2j) satisfy the conditions of equations (5a) and (5b). Thereby, even if a valve or the like is not installed in the line LA, since it is easy to spread the fluid evenly in the reactors R ₁ and R ₂ , the equipment can be simplified and long-term operation without particularly complicated operation. It is thought that you can drive stably throughout. In addition, since a valve or the like is not necessarily required at the above-mentioned position, it is considered that it is also possible to prevent clogging of the piping at a site having a complicated shape such as a valve. In addition, the methacrylic acid production apparatus 100 has a plurality of second reactors, and thus tends to easily charge the catalyst amount of the second reactor more than necessary. It is considered that it is easy to maintain the productivity of the second reactor even if the catalytic activity of the second reactor is lower than the catalytic activity of the first reactor by filling the catalyst amount of the second reactor more than necessary.

The device of the present embodiment is considered to be capable of reducing raw materials and energy during long-term operation because of its excellent continuous operability.

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

For example, separate purification means such as a distillation column and 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 piping of the line L21.

The 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 have to be connected to the separation means 60. That is, the flow supplied to the line LA via the line L23 may not be the flow recycled from the 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, in the branching portion of the line LA, it branches into n flow paths, and n flow paths join in the joining portion of the line LB. And, the reactors R ₁ to R _n are installed such that the heights A ₁ to A _n of each bottom portion satisfy Expression (2), and the heights H ₁ to H _n satisfy Expression (3), and the line The inner diameters D _1i to D _ni and the lengths L _1i to L _ni of the pipes in the respective flow paths C1i to Cni from the branch of (LA) to the inlets R _1i to R _ni of the reactors R ₁ to R _n are expressed as equations (4a). ) And the condition of formula (4b), and the inner diameter D _1j ~ of the pipes in the respective flow paths C1j to Cnj from the outlets R _1j to R _nj of reactors R ₁ to R _n to the confluence of the line LB. It is _{sufficient if} D _nj and length L _1j to L _nj satisfy the conditions of equations (5a) and (5b).

Further, even when 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 inlets and outlets in each flow path C1i to Cni is 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 the outlet in each flow path C1j to Cnj is expressed by equation (1b). It is preferable to satisfy.

10… First reactor
20… Second reactor
50b… Gas mixer
60… Separation means
100… Methacrylic acid production equipment

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 (where n represents an integer of 2 or more) to obtain methacrylic acid by reacting methacrolein and oxygen;
The line to be supplied to the respective inlet of the second reactor, R ₁ ~ R _n one reactor exit and a second reactor, R is connected to the inlet of the ₁ ~ R _n of, branches to flow out from the outlet of the first reactor (LA) and,
A second reactor R is connected to each outlet of the R ₁ ~ _n, and a second line (LB) for joining the flow out from the outlet of the reactor R ₁ ~ R _n,
The second reaction vessel R ₁ ~ R _n and the second reaction vessel R ₁ ~ R _n is installed, so that a height of the bottom of A ₁ ~ A _n meets the following formula (2),
The height H ₁ to H _n of each of the second reactors R ₁ to R _n satisfies Expression (3),
The inner diameter D _1i to D _ni and the length L _1i to L _ni of the pipes in the respective flow paths C1i to Cni from the branch of the line LA to the inlets R _1i to R _ni of the second reactors R ₁ to R _n are Satisfying the conditions of equations (4a) and (4b),
The inner diameter D _1j ~ D _nj and the length L _1j ~ L _nj of the pipe in each flow path C1j ~ Cnj from the outlets R _1j ~ R _nj of the second reactors R ₁ ~ R _n to the confluence of the line LB A device for producing methacrylic acid that satisfies the conditions of formulas (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 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 the outlet in each flow path C1i to Cni satisfies Expression (1a),
When the same fluid is passed through the flow paths C1j to Cnj at the same flow rate, methacrylic acid, in which pressure loss ΔP _1j to ΔP _nj between the inlet and the outlet in each flow path C1j to Cnj satisfies Expression (1b), 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 Indicates.]
(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 Indicates.]

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