WO2025076862A1 - Static mixing apparatus and method for phosgene and organic amine - Google Patents

Abstract

Disclosed in the present application are a static mixing apparatus and method for phosgene and organic amine. The static mixing apparatus comprises a conduit used for defining a fluid flow path, and a baffle region inside the conduit, the baffle region being a lengthwise region inside the conduit which is formed by baffle blocks and baffle plates distributed at intervals. Using the static mixing apparatus of the present application enables radial turbulence to be enhanced with less pressure energy loss, thereby comprehensively solving the technical problem proposed in the present application.

Description

A static mixing device and method for phosgene and organic amine Technical Field

The present application belongs to the field of organic synthesis, and relates to a mixing device and method, and in particular to a static mixing device and method for phosgene and organic amine.

Background Art

In industry, phosgene and polyamine compounds are usually used to react in a solvent to prepare isocyanates. In large-scale industrial processes, the amount of phosgene and solvent used is often greatly excessive to ensure that the reaction is fully carried out and to avoid the generation of by-products. However, phosgene and solvent often need to be removed in the subsequent process to obtain a high-purity isocyanate product, and this process often consumes a lot of energy. Therefore, reducing the excess rate of phosgene and solvent as much as possible is of great significance to reducing the production cost and process difficulty of isocyanates.

The reaction of phosgene with organic amines to produce isocyanates usually involves two reaction steps. The first step occurs mainly at low temperatures, and the main product is carbamoyl chloride. The second step occurs mainly at high temperatures, and carbamoyl chloride decomposes under heat to produce isocyanates.

The study found that the reaction of phosgene with organic amines to form isocyanates releases a byproduct of hydrogen chloride, which is easy to react with organic amines to form amine hydrochlorides with low solubility and precipitate in the solvent. The reaction rate of this solid substance with phosgene is significantly lower than that of the organic amine with phosgene, resulting in the unconverted amine hydrochlorides contacting with isocyanates in the subsequent reaction process to produce urea byproducts. When the side reaction is effectively suppressed, the excess rate of phosgene and solvent can be effectively reduced.

Patent CN102802773A discloses a static phosgene mixer, in which a guide element occupies the center of an otherwise tubular conduit, and when the phosgene passes through the guide element, the circular phosgene flow path is converted into an annular phosgene flow path; and organic polyamines are introduced through multiple nozzles located in the section where the annular phosgene flow path exists, thereby reducing the occurrence of side reactions by increasing the turbulence of the internal fluid.

Patent CN104010720A discloses a highly isolated jet mixer for phosgenation of amines. A conduit having injection holes on the inner or outer surface is provided, thereby improving the mixing speed and reducing the generation of undesirable by-products.

However, the lack of radial mixing effect in the existing design of the conduit leads to the inevitable formation of a stagnant flow zone near the wall, causing hydrogen chloride to react with organic amines to form amine hydrochlorides. On the other hand, the process of preparing isocyanates by the mixed reaction of phosgene and organic amines will produce a large amount of gas phase, mainly because the reaction exotherm causes the liquid phase temperature to rise, the flow in the mixer produces resistance loss, resulting in a pressure drop, and the phosgene dissolved in the liquid phase vaporizes. Phosgene vaporization will cause the phosgene concentration in the liquid phase to decrease, and the possibility of contact between organic amines and liquid phase phosgene will decrease. The energy barrier of the reaction between gas phase phosgene and organic amines is high, resulting in a decrease in the reaction rate, making the side reaction of organic amines and hydrogen chloride more likely to occur. Therefore, it is necessary not only to study how to enhance the mixing effect of phosgene and organic amines, but also to ensure that the pressure drop during the mixing process is small, thereby reducing the adverse effect of the vaporization process of the mixed stream on the reaction effect.

Summary of the invention

The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

In order to solve the above technical problems, the present application first proposes a static mixing device for phosgene and organic amine.

The present application also proposes a method for producing isocyanate using a static mixing device of phosgene and organic amine.

To achieve the above objectives, the technical solutions adopted in this application are as follows:

In a first aspect, the present application provides a static mixing device for phosgene and organic amines, comprising a conduit for defining a fluid flow path and a baffle region inside the conduit; the baffle region is a length region in a tube composed of baffle blocks 4 and baffle plates 5 distributed at intervals; the conduit comprises an inlet end for introducing an axially flowing raw material flow and an outlet end for removing a product flow;

The baffle block 4 is divided into an upper baffle block 41 and a lower baffle block 42, which are symmetrical up and down along the horizontal axis of the conduit and have a gap in the middle to form a fluid channel;

In the radial longitudinal section of the catheter with the midline of the baffle block 4 as the tangent, the upper baffle block 41 and the lower baffle block 42 are in an arc shape that is symmetrical up and down, and the arc of the arc is in close contact with the inner wall of the catheter;

In the axial longitudinal section of the catheter, the lower edge of the upper baffle block 41 is connected to two arcuate surfaces extending in opposite directions, and is smoothly connected to the inner wall of the upper end of the catheter through the arcuate surfaces; the upper edge of the lower baffle block 42 is connected to two arcuate surfaces extending in opposite directions, and is smoothly connected to the inner wall of the lower end of the catheter through the arcuate surfaces;

The baffle plate 5 is fixedly installed along the radial direction of the conduit, and its front and rear side surfaces are symmetrical convex surfaces; in the axial longitudinal section of the conduit, the baffle plate 5 is in the shape of a shuttle with sharp ends at the top and bottom and a wide middle;

In the radial longitudinal section of the conduit with the midline of the baffle 5 as the tangent, the baffle 5 is in an arc-shaped structure with the upper and lower parts being horizontal and the two ends being in contact with the inner wall of the conduit; arc-shaped gaps are formed between the upper and lower sides of the baffle 5 and the inner wall of the conduit, respectively, as fluid channels;

The front and rear ends of the deflection area are respectively provided with a front guide member 3 and a rear guide member 6; the front end of the deflection area is also provided with a plurality of nozzles 2, which are distributed in a ring shape along the side wall of the conduit.

As an optional solution in the static mixing device of the present application, the front guide member 3 and the rear guide member 6 are both conical, and they are aligned with the central axis of the conduit; the cone vertex angle of the front guide member 3 is in the front, and the cone vertex angle of the rear guide member 6 is in the rear, and the two are distributed in opposite directions; the front guide member 3 and the rear guide member 6 respectively form annular channels for feeding and discharging with the inner wall of the conduit;

In one embodiment, the cone vertex angles of the front guide member 3 and the rear guide member 6 are in the range of 25-75°, and may be 40-60°;

In one embodiment, the diameter of the conical bottom surface of the front flow guide 3 and the rear flow guide 6 is 90-95% of the inner diameter of the conduit, and can be optionally 92-93%.

As an optional solution in the static mixing device of the present application, the nozzle is located at the rear end of the front guide member 3. The vertical distance from the center point of the ring formed by the multiple nozzles to the bottom surface of the front guide member 3 is 20-40 mm;

In one embodiment, the number of the nozzles is 5-20;

In one embodiment, the diameter of the nozzle is 5-30 mm, and optionally 10-25 mm.

As an optional solution in the static mixing device of the present application, the baffle area starts from the first pair of baffle blocks and ends at the last pair of baffle blocks, so that the flow path formed after it is connected with the front guide member 3 and the rear guide member 6 is smooth;

In one embodiment, the number of the baffles is 4-9 pairs;

In one embodiment, adjacent baffles on the same side of the conduit are smoothly connected or spaced from each other;

In one embodiment, the spacing distance between adjacent baffles on the same side of the conduit is 0.1-0.8 times the inner diameter of the conduit.

As an optional solution in the static mixing device of the present application, in the radial longitudinal section of the conduit with the midline of the baffle (4) as the tangent, the gap area (i.e., the flow area) S1 between the upper baffle 41 and the lower baffle 42 is 10-30% of the conduit cross-sectional area S0;

In one embodiment, in the radial longitudinal section of the catheter with the center line of the baffle 5 as the tangent, the total area S2 of the arc-shaped notches on the upper and lower sides of the baffle 5 is greater than or equal to the notch area S1 between the upper baffle block 41 and the lower baffle block 42.

As an optional solution in the static mixing device of the present application, the height of the baffle plate 5 is greater than the spacing height between the lower edge of the upper baffle block 41 and the upper edge of the lower baffle block 42;

In one embodiment, the center thickness of the baffle 5 is 10-30 mm.

As an optional solution in the static mixing device of the present application, the axial length of the baffle area is 5-15 times the inner diameter of the conduit;

In one embodiment, the diameter of the conduit is 100-500 mm, and optionally 200-400 mm.

In a second aspect, the present application provides a method for producing isocyanate using the static mixing device of phosgene and organic amine as described in the first aspect, comprising the following steps:

An axially flowing phosgene flow is introduced from the inlet end of the conduit, and at the same time, an organic amine flow is injected into the conduit from a nozzle, so that the phosgene flow is mixed with the organic amine flow after diversion and fully mixed and reacted through multi-stage deflection to produce isocyanate.

As an optional solution in the static mixing device of the present application, the feed temperature of the phosgene flow is -20°C to 30°C, and the operating pressure is 0.3-4Mpag;

In one embodiment, the feed temperature of the organic amine stream is 45-120°C and the operating pressure is 0.35-4.05Mpag;

In one embodiment, the feed amounts of the phosgene flow and the organic amine flow are 1.1-4 in terms of the mass ratio of phosgene to organic amine.

As an optional solution in the static mixing device of the present application, the phosgene flow is pure phosgene or a mixture of phosgene and a solvent; in one embodiment, the mass content of phosgene in the phosgene flow is 60-99%, optionally 70-80%;

In one embodiment, the organic amine stream is a mixture of an organic amine and a solvent, wherein the mass content of the organic amine is 35-75%, and optionally 55-65%;

In one embodiment, the organic amine is selected from one or more of toluenediamine, diphenylmethanediamine, 1,6-hexanediamine, polymethylene polyphenyl polyamines, and meta-xylylenediamine;

In one embodiment, the solvent is selected from at least one of chlorobenzene, dichlorobenzene, diethyl carbonate, dimethyl carbonate, and toluene.

Research has found that simply increasing the turbulence in the radial direction of the conduit by setting baffles will lead to a large loss of pressure energy, which will cause the phosgene dissolved in the solvent to vaporize and deteriorate the reaction effect. The static mixing device of the present application can enhance the radial turbulence with a small loss of pressure energy, thereby comprehensively solving the problem of Solve the technical problems raised in this application.

Other aspects will be apparent upon reading and understanding the drawings and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are used to provide further understanding of the technical solution of this article and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of this article and do not constitute a limitation on the technical solution of this article.

FIG. 1 is a schematic diagram of the internal structure of an axial longitudinal section of a conduit in a static mixing device in Example 1.

Figure 2 is a schematic structural diagram of a radial longitudinal section of a conduit at the midline of a baffle in a static mixing device in Example 1.

3 is a schematic structural diagram of a radial longitudinal section of a conduit at the center line of a baffle in a static mixing device in Example 1.

FIG4 is a schematic diagram of the internal structure of the axial longitudinal section of the conduit in the static mixing device of Comparative Example 1.

Figure 5 is a schematic diagram of the internal structure of the axial longitudinal section of the conduit in the static mixing device of Comparative Example 2.

Figure 6 is a schematic diagram of the internal structure of the axial longitudinal section of the conduit in the static mixing device of Comparative Example 3.

In the figure: 1, conduit; 2, nozzle; 3, front guide piece; 4, deflector; 41, upper deflector; 42, lower deflector; 5, deflector plate; 6, rear guide piece.

DETAILED DESCRIPTION

The present application is further described below through specific embodiments. The embodiments described in the present application are only used as an explanation of the present application and do not limit the scope of the present application.

Unless otherwise specified, the raw materials in this application can be purchased from commercial sources.

The main test methods used in the following examples of this application are as follows:

(1) Determination of hydrochloride content in the reaction liquid at the outlet of the static mixer: The hydrochloride content in the cold reaction was determined by liquid phase, chromatographic conditions: Agilent 1620, chromatographic column waters C18 (4.6*250mm), DAD detector, detection wavelength 254nm; mobile phase: acetonitrile and water gradient elution. Pretreatment method: take 0.2g sample, add 2.5g methanol, derivatize at 70 degrees for 60min, pass through 0.45μm organic membrane, put into liquid phase vial, wait for liquid phase analysis. The results are quantitatively analyzed by area percentage.

(2) Method for determining the content of acyl chloride in the reaction liquid at the outlet of the static mixer: The acyl chloride was determined by GPC chromatography. Chromatographic conditions: Agilent 1620, chromatographic column PLgel 5μm 300*7.5mm, RID detector detection. Pretreatment method: Take 0.1g sample in a liquid phase bottle, add 1mL THF, shake well and analyze by GPC. The results were quantitatively analyzed by the area percentage method.

(3) Method for measuring pressure energy loss: Add pressure monitoring instruments at 2 pipe diameters upstream and 2 pipe diameters downstream of the static mixer. The pressure energy loss is characterized by the ratio of the difference in the pressure monitoring values at the two locations (static mixer pressure drop) to the inlet pressure of the phosgene flow.

Example 1

As shown in FIG1 , a static mixing device for phosgene and organic amines comprises a conduit for defining a fluid flow path and a baffle region inside the conduit; the baffle region is a length region in the tube composed of baffle blocks 4 and baffle plates 5 distributed at intervals; the conduit comprises an inlet end for introducing an axially flowing raw material flow and an outlet end for removing a product flow;

The baffle block 4 is divided into an upper baffle block 41 and a lower baffle block 42, which are symmetrical up and down along the horizontal axis of the conduit and have a gap in the middle to form a fluid channel;

As shown in FIG. 2 , in the radial longitudinal section of the catheter with the midline of the baffle block 4 as the tangent, the upper baffle block 41 and the lower baffle block 42 are in an arc shape that is symmetrical up and down, and the arc of the arc is in close contact with the inner wall of the catheter;

In the axial longitudinal section of the catheter, the lower edge of the upper baffle block 41 is connected to two arcuate surfaces extending in opposite directions, and is smoothly connected to the inner wall of the upper end of the catheter through the arcuate surfaces; the upper edge of the lower baffle block 42 is connected to two arcuate surfaces extending in opposite directions, and is smoothly connected to the inner wall of the lower end of the catheter through the arcuate surfaces;

The baffle plate 5 is fixedly installed along the radial direction of the conduit, and its front and rear sides are symmetrical convex surfaces; In the axial longitudinal section of the catheter, the baffle 5 is in the shape of a shuttle with sharp ends at the top and bottom and wide in the middle;

As shown in FIG3 , in the radial longitudinal section of the conduit with the midline of the baffle 5 as the tangent, the baffle 5 is in an arc-shaped structure with the upper and lower sides being horizontal and the two ends being in contact with the inner wall of the conduit; arc-shaped notches are formed between the upper and lower sides of the baffle 5 and the inner wall of the conduit, respectively, as fluid channels;

The front and rear ends of the deflection area are respectively provided with a front guide member 3 and a rear guide member 6; the front end of the deflection area is also provided with a plurality of nozzles 2, which are distributed in a ring shape along the side wall of the conduit.

The front guide piece 3 and the rear guide piece 6 are both conical, and they are aligned with the central axis of the conduit; the cone vertex angle of the front guide piece 3 is in the front, and the cone vertex angle of the rear guide piece 6 is in the rear, and the two are distributed in opposite directions; the front guide piece 3 and the rear guide piece 6 form annular channels for feeding and discharging materials with the inner wall of the conduit respectively;

Specifically, the angle range of the cone vertex angle of the front guide member 3 and the rear guide member 6 is 45°, and the diameter of their cone bottom surface is 90% of the inner diameter of the conduit;

Specifically, the nozzle is located at the rear end of the front guide member 3, and the vertical distance from the center point of the ring surrounded by the multiple nozzles to the bottom surface of the front guide member 3 is 20 mm;

Specifically, the number of the nozzles 2 is 12, and the nozzles are circular with a diameter of 15 mm.

Specifically, the baffle area starts from the first pair of baffle blocks and ends with the last pair of baffle blocks, so that the flow path formed after the baffle blocks are connected with the front guide member 3 and the rear guide member 6 is smooth; the number of the baffle blocks is 7 pairs;

Specifically, adjacent baffle blocks on the same side of the conduit are spaced apart from each other; and the spacing distance between adjacent baffle blocks on the same side of the conduit is 0.4 times the inner diameter of the conduit.

Specifically, in the radial longitudinal section of the conduit with the midline of the baffle block 4 as the tangent, the gap area (i.e., the flow area) S1 between the upper baffle block 41 and the lower baffle block 42 is 20% of the conduit cross-sectional area S0;

Specifically, in the radial longitudinal section of the catheter with the midline of the baffle 5 as the tangent, the total area S2 of the arc-shaped gaps on the upper and lower sides of the baffle 5 is equal to the gap area between the upper baffle block 41 and the lower baffle block 42. S1.

Specifically, the height of the baffle plate 5 is greater than the spacing height between the lower edge of the upper baffle block 41 and the upper edge of the lower baffle block 42;

Specifically, the center thickness of the baffle plate 5 is 10 mm.

Specifically, the axial length of the baffle area is 15 times the inner diameter of the catheter;

Specifically, the diameter of the conduit is 200 mm.

Example 2

A static mixing device for phosgene and organic amines, comprising a conduit for defining a fluid flow path and a baffle area inside the conduit; the baffle area is a length area in the tube composed of baffle blocks 4 and baffle plates 5 distributed at intervals; the conduit comprises an inlet end for introducing an axially flowing raw material flow and an outlet end for removing a product flow;

The baffle block 4 is divided into an upper baffle block 41 and a lower baffle block 42, which are symmetrical up and down along the horizontal axis of the conduit and have a gap in the middle to form a fluid channel;

In the radial longitudinal section of the catheter with the midline of the baffle block 4 as the tangent, the upper baffle block 41 and the lower baffle block 42 are in an arc shape that is symmetrical up and down, and the arc of the arc is in close contact with the inner wall of the catheter;

In the axial longitudinal section of the catheter, the lower edge of the upper baffle block 41 is connected to two arcuate surfaces extending in opposite directions, and is smoothly connected to the inner wall of the upper end of the catheter through the arcuate surfaces; the upper edge of the lower baffle block 42 is connected to two arcuate surfaces extending in opposite directions, and is smoothly connected to the inner wall of the lower end of the catheter through the arcuate surfaces;

The baffle plate 5 is fixedly installed along the radial direction of the conduit, and its front and rear side surfaces are symmetrical convex surfaces; in the axial longitudinal section of the conduit, the baffle plate 5 is in the shape of a shuttle with sharp ends at the top and bottom and a wide middle;

In the radial longitudinal section of the conduit with the midline of the baffle 5 as the tangent, the baffle 5 is in an arc-shaped structure with the upper and lower parts being horizontal and the two ends being in contact with the inner wall of the conduit; arc-shaped gaps are formed between the upper and lower sides of the baffle 5 and the inner wall of the conduit, respectively, as fluid channels;

The front and rear ends of the deflection area are respectively provided with a front guide member 3 and a rear guide member 6; the front end of the deflection area is also provided with a plurality of nozzles 2, which are distributed in a ring shape along the side wall of the conduit.

The front guide piece 3 and the rear guide piece 6 are both conical, and they are aligned with the central axis of the conduit; the cone vertex angle of the front guide piece 3 is in the front, and the cone vertex angle of the rear guide piece 6 is in the rear, and the two are distributed in opposite directions; the front guide piece 3 and the rear guide piece 6 form annular channels for feeding and discharging materials with the inner wall of the conduit respectively;

Specifically, the angle range of the cone vertex angle of the front flow guide 3 and the rear flow guide 6 is 25°, and the diameter of their cone bottom surface is 95% of the inner diameter of the conduit;

Specifically, the nozzle is located at the rear end of the front guide member 3, and the vertical distance from the center point of the ring surrounded by the multiple nozzles to the bottom surface of the front guide member 3 is 30 mm;

Specifically, the number of the nozzles 2 is 5, and the nozzles are circular with a diameter of 30 mm.

Specifically, the baffle area starts from the first pair of baffle blocks and ends with the last pair of baffle blocks, so that the flow path formed after the baffle blocks are connected with the front guide member 3 and the rear guide member 6 is smooth; the number of the baffle blocks is 5 pairs;

Specifically, adjacent baffle blocks on the same side of the conduit are spaced apart from each other; and the spacing distance between adjacent baffle blocks on the same side of the conduit is 0.8 times the inner diameter of the conduit.

Specifically, in the radial longitudinal section of the conduit with the midline of the baffle block 4 as the tangent, the gap area (i.e., the flow area) S1 between the upper baffle block 41 and the lower baffle block 42 is 10% of the conduit cross-sectional area S0;

Specifically, in the radial longitudinal section of the catheter with the center line of the baffle 5 as the tangent, the total area S2 of the arc-shaped notches on the upper and lower sides of the baffle 5 is equal to the notch area S1 between the upper baffle block 41 and the lower baffle block 42.

Specifically, the height of the baffle plate 5 is greater than the spacing height between the lower edge of the upper baffle block 41 and the upper edge of the lower baffle block 42;

Specifically, the center thickness of the baffle plate 5 is 30 mm.

Specifically, the axial length of the baffle area is 5 times the inner diameter of the catheter;

Specifically, the diameter of the conduit is 100 mm.

Example 3

A static mixing device for phosgene and organic amines, comprising a conduit for defining a fluid flow path and a baffle area inside the conduit; the baffle area is a length area in the tube composed of baffle blocks 4 and baffle plates 5 distributed at intervals; the conduit comprises an inlet end for introducing an axially flowing raw material flow and an outlet end for removing a product flow;

The baffle block 4 is divided into an upper baffle block 41 and a lower baffle block 42, which are symmetrical up and down along the horizontal axis of the conduit and have a gap in the middle to form a fluid channel;

In the radial longitudinal section of the catheter with the midline of the baffle block 4 as the tangent, the upper baffle block 41 and the lower baffle block 42 are in an arc shape that is symmetrical up and down, and the arc of the arc is in close contact with the inner wall of the catheter;

In the axial longitudinal section of the catheter, the lower edge of the upper baffle block 41 is connected to two arcuate surfaces extending in opposite directions, and is smoothly connected to the inner wall of the upper end of the catheter through the arcuate surfaces; the upper edge of the lower baffle block 42 is connected to two arcuate surfaces extending in opposite directions, and is smoothly connected to the inner wall of the lower end of the catheter through the arcuate surfaces;

The baffle plate 5 is fixedly installed along the radial direction of the conduit, and its front and rear side surfaces are symmetrical convex surfaces; in the axial longitudinal section of the conduit, the baffle plate 5 is in the shape of a shuttle with sharp ends at the top and bottom and a wide middle;

In the radial longitudinal section of the conduit with the midline of the baffle 5 as the tangent, the baffle 5 is in an arc-shaped structure with the upper and lower parts being horizontal and the two ends being in contact with the inner wall of the conduit; arc-shaped gaps are formed between the upper and lower sides of the baffle 5 and the inner wall of the conduit, respectively, as fluid channels;

The front and rear ends of the deflection area are respectively provided with a front guide member 3 and a rear guide member 6; the front end of the deflection area is also provided with a plurality of nozzles 2, which are distributed in a ring shape along the side wall of the conduit.

The front guide member 3 and the rear guide member 6 are both conical, and they are aligned with the central axis of the conduit; the cone vertex angle of the front guide member 3 is at the front, and the cone vertex angle of the rear guide member 6 is at the rear, and the two are distributed in opposite directions; The front guide piece 3 and the rear guide piece 6 respectively form an annular channel for feeding and discharging materials with the inner wall of the conduit;

Specifically, the angle range of the cone vertex angle of the front guide member 3 and the rear guide member 6 is 75°, and the diameter of their cone bottom surface is 93% of the inner diameter of the conduit;

Specifically, the nozzle is located at the rear end of the front guide member 3, and the vertical distance from the center point of the ring surrounded by the multiple nozzles to the bottom surface of the front guide member 3 is 40 mm;

Specifically, the number of the nozzles 2 is 20, and the nozzles are circular with a diameter of 5 mm.

Specifically, the baffle area starts from the first pair of baffle blocks and ends with the last pair of baffle blocks, so that the flow path formed after the baffle blocks are connected with the front guide member 3 and the rear guide member 6 is smooth; the number of the baffle blocks is 7 pairs;

Specifically, adjacent baffles on the same side of the conduit are connected with a smooth transition.

Specifically, in the radial longitudinal section of the conduit with the midline of the baffle block 4 as the tangent, the gap area (i.e., the flow area) S1 between the upper baffle block 41 and the lower baffle block 42 is 30% of the conduit cross-sectional area S0;

Specifically, in the radial longitudinal section of the catheter with the center line of the baffle 5 as the tangent, the total area S2 of the arc-shaped notches on the upper and lower sides of the baffle 5 is equal to the notch area S1 between the upper baffle block 41 and the lower baffle block 42.

Specifically, the height of the baffle plate 5 is greater than the spacing height between the lower edge of the upper baffle block 41 and the upper edge of the lower baffle block 42;

Specifically, the center thickness of the baffle 5 is 20 mm.

Specifically, the axial length of the baffle area is 8 times the inner diameter of the catheter;

Specifically, the diameter of the conduit is 500 mm.

Example 4

A method for producing isocyanate using the static mixing device in Example 1 comprises the following steps:

The axially flowing phosgene stream is introduced from the inlet end of the conduit, and at the same time, the organic amine stream is injected into the conduit from the nozzle. In the process, the phosgene flow is guided and mixed with the organic amine flow, and the mixture is fully mixed and reacted through multi-stage deflection to produce isocyanate.

The phosgene stream comprises 60 wt% of phosgene and 40 wt% of o-dichlorobenzene; the feed flow rate of the phosgene stream is 26 kg/s, the feed temperature is -20°C, and the operating pressure is 0.3 Mpag;

The organic amine logistics includes 75wt% toluenediamine and 25wt% solvent chlorobenzene; the feed flow rate of the organic amine logistics is 6.5kg/s, the feed temperature is 45°C, and the operating pressure is 0.35Mpag;

After the reaction was completed, the acyl chloride, amine hydrochloride in the reaction solution at the outlet of the static mixer and the pressure drop of the static mixer were monitored. The results are shown in Table 1.

Example 5

A method for producing isocyanate using the static mixing device in Example 2 comprises the following steps:

An axially flowing phosgene flow is introduced from the inlet end of the conduit, and at the same time, an organic amine flow is injected into the conduit from a nozzle, so that the phosgene flow is mixed with the organic amine flow after diversion and fully mixed and reacted through multi-stage deflection to produce isocyanate.

The phosgene stream comprises 70 wt% phosgene and 30 wt% chlorobenzene; the feed flow rate of the phosgene stream is 26 kg/s, the feed temperature is 15° C., and the operating pressure is 3 Mpag;

The organic amine logistics includes 35 wt% of diphenylmethanediamine and 65 wt% of solvent chlorobenzene; the feed flow rate of the organic amine logistics is 10 kg/s, the feed temperature is 120° C., and the operating pressure is 3.2 Mpag.

After the reaction was completed, the acyl chloride, amine hydrochloride in the reaction solution at the outlet of the static mixer and the pressure drop of the static mixer were monitored. The results are shown in Table 1.

Example 6

A method for producing isocyanate using the static mixing device in Example 3 comprises the following steps:

An axially flowing phosgene stream is introduced from the inlet end of the conduit, and at the same time, an organic amine stream is injected into the conduit from the nozzle, so that the phosgene stream is mixed with the organic amine stream after being guided and fully mixed and reacted through multi-stage deflection to produce Produces isocyanates.

The phosgene stream comprises 90 wt% of phosgene and 10 wt% of diethyl carbonate; the feed flow rate of the phosgene stream is 26 kg/s, the feed temperature is 30° C., and the operating pressure is 4.0 Mpag;

The organic amine stream includes 45 wt% of diphenylmethanediamine and 55 wt% of solvent diethyl carbonate; the feed flow rate of the organic amine stream is 23.6 kg/s, the feed temperature is 80° C., and the operating pressure is

After the reaction was completed, the acyl chloride, amine hydrochloride in the reaction solution at the outlet of the static mixer and the pressure drop of the static mixer were monitored. The results are shown in Table 1.

Comparative Example 1

A static mixing device for phosgene and organic amines, the structure of which is substantially the same as that of the static mixing device in Example 1, except that, in the axial longitudinal section of the conduit, the baffle is in the shape of a straight strip and does not have an arc surface. A schematic diagram of the internal structure of the axial longitudinal section of the conduit in the static mixing device is shown in FIG4 .

Comparative Example 2

A static mixing device for phosgene and organic amines, the structure of which is substantially the same as that of the static mixing device in Example 1, except that, in the axial longitudinal section of the conduit, the baffle is in the shape of a straight strip and does not have two convex surfaces. A schematic diagram of the internal structure of the axial longitudinal section of the conduit in the static mixing device is shown in FIG5 .

Comparative Example 3

A static mixing device for phosgene and organic amines, the structure of which is substantially the same as that of the static mixing device in Example 1, except that, in the axial longitudinal section of the conduit, the baffle is in the shape of a straight strip and does not have a curved surface; meanwhile, the baffle is in the shape of a straight strip and does not have two convex surfaces. A schematic diagram of the internal structure of the axial longitudinal section of the conduit in the static mixing device is shown in FIG6 .

Comparative Example 4

Isocyanate was produced in substantially the same manner as in Example 4, except that the static mixing device provided in Comparative Example 1 was used in the method.

After the reaction was completed, the acyl chloride, amine hydrochloride in the reaction solution at the outlet of the static mixer and the pressure drop of the static mixer were monitored. The results are shown in Table 1.

Comparative Example 5

Isocyanate was produced in substantially the same manner as in Example 4, except that the static mixing device provided in Comparative Example 2 was used in the method.

After the reaction was completed, the acyl chloride, amine hydrochloride in the reaction solution at the outlet of the static mixer and the pressure drop of the static mixer were monitored. The results are shown in Table 1.

Comparative Example 6

Isocyanate was produced in substantially the same manner as in Example 4, except that the static mixing device provided in Comparative Example 3 was used in the method.

After the reaction was completed, the acyl chloride, amine hydrochloride in the reaction solution at the outlet of the static mixer and the pressure drop of the static mixer were monitored. The results are shown in Table 1.

Table 1. Performance test results

It can be concluded from the results in Table 1 that the use of the static mixing device of the present application can effectively reduce the pressure loss during the static mixing process, while obtaining an outlet mixed solution with a higher content of acyl chloride and a lower content of hydrochloride, effectively improving the reaction effect.

The above is only a preferred embodiment of the present application. It should be noted that a person skilled in the art can make several improvements and additions without departing from the method of the present application. Improvements and supplements should also be considered as the protection scope of this application.

Claims (10)

A static mixing device for phosgene and organic amines, comprising a conduit for defining a fluid flow path and a baffle region inside the conduit; the baffle region is a length region inside the tube formed by baffle blocks (4) and baffle plates (5) distributed at intervals; The baffle block (4) is divided into an upper baffle block (41) and a lower baffle block (42), which are symmetrical up and down along the horizontal axis of the conduit and have a gap in the middle to form a fluid channel; In a radial longitudinal section of the catheter with the midline of the baffle block (4) as a tangent, the upper baffle block (41) and the lower baffle block (42) are in an arc shape that is symmetrical up and down, and the arc of the arc is in close contact with the inner wall of the catheter; In the axial longitudinal section of the catheter, the lower edge of the upper baffle block (41) is connected to two arcuate surfaces extending in opposite directions, and is smoothly connected to the inner wall of the upper end of the catheter through the arcuate surfaces; the upper edge of the lower baffle block (42) is connected to two arcuate surfaces extending in opposite directions, and is smoothly connected to the inner wall of the lower end of the catheter through the arcuate surfaces; The baffle (5) is fixedly installed along the radial direction of the conduit, and its front and rear side surfaces are symmetrical convex surfaces; in the axial longitudinal section of the conduit, the baffle (5) is in the shape of a shuttle with pointed upper and lower ends and a wide middle; In a radial longitudinal section of the conduit with the midline of the baffle (5) as a tangent, the baffle (5) is in an arc-shaped structure with the upper and lower sides being horizontal and the two ends being in close contact with the inner wall of the conduit; arc-shaped notches are respectively formed between the upper and lower sides of the baffle (5) and the inner wall of the conduit to serve as a fluid channel; A front guide piece (3) and a rear guide piece (6) are respectively arranged at the front and rear ends of the baffle area; a plurality of nozzles (2) are also arranged at the front end of the baffle area, and the plurality of nozzles are distributed in a ring shape along the side wall of the conduit. The static mixing device of phosgene and organic amine according to claim 1, wherein the front flow guide (3) and the rear flow guide (6) are both conical, and they are aligned with the central axis of the conduit; the cone vertex angle of the front flow guide (3) is at the front, and the cone vertex angle of the rear flow guide (6) is at the rear, and the two are distributed in opposite directions; Optionally, the cone vertex angles of the front guide member (3) and the rear guide member (6) are in the range of 25-75°, and can further be in the range of 40-60°; Optionally, the diameter of the conical bottom surface of the front guide member (3) and the rear guide member (6) is equal to the inner diameter of the conduit. 90-95%, further optionally 92-93%. The static mixing device of phosgene and organic amine according to claim 1 or 2, wherein the nozzle is located at the rear end of the front guide member (3), and the vertical distance from the center point of the ring formed by the multiple nozzles to the bottom surface of the front guide member (3) is 20-40 mm; Optionally, the number of the nozzles is 5-20; Optionally, the diameter of the nozzle is 5-30 mm, further optionally 10-25 mm. The static mixing device for phosgene and organic amine according to any one of claims 1 to 3, wherein the baffle area starts from the first pair of baffle blocks and ends with the last pair of baffle blocks, so that the flow path formed after the baffle area is connected with the front guide member (3) and the rear guide member (6) is smooth; Optionally, the number of the baffles is 4-9 pairs; Optionally, adjacent baffles on the same side of the conduit are smoothly connected or spaced from each other; Optionally, the spacing distance between adjacent baffles on the same side of the conduit is 0.1-0.8 times the inner diameter of the conduit. The static mixing device for phosgene and organic amine according to any one of claims 1 to 4, wherein, in the radial longitudinal section of the conduit with the center line of the baffle block (4) as the tangent, the gap area S1 between the upper baffle block (41) and the lower baffle block (42) is 10-30% of the conduit cross-sectional area S0; Optionally, in a radial longitudinal section of the catheter with the center line of the baffle (5) as the tangent, the total area S2 of the arc-shaped notches on the upper and lower sides of the baffle (5) is greater than or equal to the notch area S1 between the upper baffle block (41) and the lower baffle block (42). The static mixing device for phosgene and organic amine according to any one of claims 1 to 5, wherein the height of the baffle plate (5) is greater than the spacing height between the lower edge of the upper baffle block (41) and the upper edge of the lower baffle block (42); Optionally, the center thickness of the baffle (5) is 10-30 mm. The static mixing device of phosgene and organic amine according to any one of claims 1 to 6, wherein: The axial length of the baffle area is 5-15 times the inner diameter of the catheter; Optionally, the diameter of the conduit is 100-500 mm, further optionally 200-400 mm. A method for producing isocyanate using the static mixing device of phosgene and organic amine according to any one of claims 1 to 7, comprising the following steps: An axially flowing phosgene flow is introduced from the inlet end of the conduit, and at the same time, an organic amine flow is injected into the conduit from a nozzle, so that the phosgene flow is mixed with the organic amine flow after diversion and fully mixed and reacted through multi-stage deflection to produce isocyanate. The method according to claim 8, wherein the feed temperature of the phosgene stream is -20°C to 30°C and the operating pressure is 0.3-4Mpag; Optionally, the feed temperature of the organic amine stream is 45-120°C and the operating pressure is 0.35-4.05Mpag; Optionally, the feed amounts of the phosgene flow and the organic amine flow are 1.1-4 based on the mass ratio of phosgene to organic amine. The method according to claim 8, wherein the phosgene flow is pure phosgene or a mixture of phosgene and a solvent; Optionally, the mass content of phosgene in the phosgene flow is 60-99%, further optionally 70-80%; Optionally, the organic amine stream is a mixture of an organic amine and a solvent, wherein the mass content of the organic amine is 35-75%, and further optionally 55-65%; Optionally, the organic amine is selected from one or more of toluenediamine, diphenylmethanediamine, 1,6-hexanediamine, polymethylene polyphenyl polyamines, and meta-xylylenediamine; Optionally, the solvent is selected from at least one of chlorobenzene, dichlorobenzene, diethyl carbonate, dimethyl carbonate and toluene.