Process for producing 1, 3-xylylenediamine by continuous method

Abstract

The invention provides a process for producing 1, 3-xylylenediamine by a continuous method, and relates to the field of xylylenediamine preparation, and the process comprises the following steps: S1, mixing a raw material for producing 1, 3-xylylenediamine and a catalyst through a mixing device to obtain a mixed raw material; s2, the mixed raw materials are input into a reaction device through a first conveying pipe, hydrogen is input into the reaction device from a hydrogen supply system through a second conveying pipe, outlets of the first conveying pipe and the second conveying pipe are both connected to the bottom of the reaction device, the raw materials for producing 1, 3-xylylenediamine react with a catalyst in the reaction device under pushing of hydrogen pressure, and 1, 3-xylylenediamine is obtained. A separator is arranged at the top of the reaction device, and residual hydrogen after reaction is separated by the separator and then is output through the top of the reaction device; in the step S2, an air pressure monitoring and early warning module carries out monitoring and early warning. In the reaction process, the air pressure monitoring and early warning module carries out monitoring and early warning, timely early warning and reminding adjustment are facilitated when the air pressure is abnormal, and it is guaranteed that the reaction state is more reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of the preparation of phthalyl diamine, and specifically to a process for continuously producing 1,3 - phthalyl diamine. Background Art

[0002] The molecular formula of 1,3 - phthalyl diamine is C8H12N2. It is a colorless liquid at room temperature and is an important chemical raw material. It is used as a room - temperature and low - toxicity curing agent for epoxy resin, and also as a raw material for photosensitive plastics, rubber auxiliaries, polyurethane resins and coatings production, and as an intermediate for organic synthesis.

[0003] In the prior art, 1,3 - phthalyl diamine (i.e., m - xylylenediamine) is prepared by hydrogenating m - phthalonitrile. For example, the method for hydrogenating m - phthalonitrile to m - xylylenediamine in CN103539676A has the following problems:

[0004] The monitoring and early warning of the production process are not disclosed. For example, the monitoring and early warning of the air pressure state in the reaction zone during the reaction are not disclosed, which is likely to affect the reaction effect. Summary of the Invention

[0005] The present invention provides a process for continuously producing 1,3 - phthalyl diamine to solve the technical problems raised in the above - mentioned background art.

[0006] To solve the above - mentioned technical problems, the present invention discloses a process for continuously producing 1,3 - phthalyl diamine, including:

[0007] Step S1: After mixing the raw materials for producing 1,3 - phthalyl diamine and a catalyst through a mixing device, the mixed raw materials are obtained.

[0008] Step S2: The mixed raw materials are input into the reaction device through a first conveying pipe. A first conveying pump is connected to the first conveying pipe. Hydrogen is input into the reaction device from a hydrogen supply system through a second conveying pipe. The outlets of the first conveying pipe and the second conveying pipe are both connected to the bottom of the reaction device. The raw materials for producing 1,3 - phthalyl diamine react with the catalyst in the reaction device under the push of hydrogen pressure. The top of the reaction device is a separator. The remaining hydrogen after the reaction is separated by the separator and output through the top of the reaction device.

[0009] During step S2, monitoring and early warning are carried out based on an air pressure monitoring and early warning module.

[0010] Preferably, the raw materials for producing 1,3 - phthalyl diamine include: m - phthalonitrile, a solvent and a reaction assistant.

[0011] Preferably, the catalyst is a granular solid catalyst.

[0012] During step S2, the intelligent hydrogen supply process of the hydrogen supply system includes:

[0013] Step S21: Obtain the standard hydrogen gas pressure corresponding to the current mixed raw material that matches the first parameter of the current mixed raw material and the target flow rate range of the current mixed raw material;

[0014] Step S22: Control the hydrogen supply system to work based on the standard hydrogen gas pressure corresponding to the current mixed raw material, and supply hydrogen to the reaction device.

[0015] Preferably, step S21 includes:

[0016] Step S211: Obtain the first parameter of the current mixed raw material and determine the stacking state parameter of the current mixed raw material; the first parameter of the current mixed raw material includes: the density of the granular solid catalyst in the current mixed raw material; the weight percentage of the granular solid catalyst in the current mixed raw material; in the formula of the current mixed raw material, the density of the other materials after mixing except the granular solid catalyst; the sum of the weight percentages of the other materials except the granular solid catalyst in the formula of the current mixed raw material;

[0017] ρ = A2ρ2 + A1ρ1;

[0018] ρ is the stacking state parameter of the current mixed raw material, ρ1 is the density of the granular solid catalyst in the current mixed raw material; A1 is the weight percentage of the granular solid catalyst in the current mixed raw material; ρ2 is the density of the other materials after mixing except the granular solid catalyst in the formula of the current mixed raw material; A2 is the sum of the weight percentages of the other materials except the granular solid catalyst in the formula of the current mixed raw material;

[0019] Step S212: Obtain the viscosity of the other materials after mixing except the granular solid catalyst in the formula of the current mixed raw material;

[0020] Step S213: Calculate the standard hydrogen gas pressure corresponding to the current mixed raw material based on step S211 and step S212;

[0021]

[0022] P is the standard hydrogen gas pressure corresponding to the current mixed raw material; is the minimum value of the target flow rate range of the current mixed raw materials; S is the cross-sectional area of the outlet of the first conveying pipe, ρ3 is the density of hydrogen; F is the reference hydrogen driving force required for the hydrogenation reaction of the mixed raw materials; d is the particle size of the granular solid catalyst; δ is the viscosity after mixing of other materials in the current formula of the mixed raw materials except the granular solid catalyst; θ1 is the angle between the axis of the outlet of the first conveying pipe and the horizontal direction; θ2 is the angle between the axis of the outlet of the second conveying pipe and the horizontal direction; sin is the sine; ρ0 is the reference raw material packing parameter of the mixed raw materials; ln is the natural logarithm.

[0023] Preferably, the air pressure monitoring and warning module includes:

[0024] An air pressure sensor. The reaction zone of the reaction device is divided into multiple sub-reaction zones along the hydrogen flow direction, and multiple air pressure sensors are arranged in each sub-reaction zone. During the reaction process, the air pressure sensors detect the air pressure at their locations in real time;

[0025] A storage module for storing the detection values of the air pressure sensors;

[0026] A first control device, a first alarm and display device, a first timer, and a storage module. The first control device is electrically connected to the air pressure sensor, the first alarm and display device, the first timer, and the storage module respectively.

[0027] Preferably, the monitoring and warning based on the air pressure monitoring and warning module includes:

[0028] During the reaction process, at each interval duration, the first control device obtains the detection values of the air pressure sensors in the latest historical detection period, and calculates the first air pressure state value of each sub-reaction zone and the second air pressure state value of each sub-reaction zone based on the detection values of the air pressure sensors in the latest historical detection period;

[0029]

[0030] E ri is the first air pressure state value of the i-th sub-reaction zone in the r-th reaction zone of the latest historical detection period; P ri1 is the average detection value of the air pressure sensor in the i-th sub-reaction zone of the r-th reaction zone in the latest historical detection period; P ri0 is the standard air pressure of the i-th sub-reaction zone in the r-th reaction zone; Q ri is the second air pressure state value of the i-th sub-reaction zone in the r-th reaction zone of the latest historical detection period; P ri+11 is the average detection value of the air pressure sensor in the (i + 1)-th sub-reaction zone of the r-th reaction zone in the latest historical detection period; ∈1, ∈2, ∈3, ∈4 are the first air pressure evaluation weight, the second air pressure evaluation weight, the third air pressure evaluation weight, and the fourth air pressure evaluation weight respectively;

[0031] When E ri ≥ E ri1 , determine that the i-th sub-reaction zone of the r-th reaction zone in the current historical detection period is a clogging warning sub-reaction zone; E ri1 is the first preset air pressure state value of the i-th sub-reaction zone of the r-th reaction zone;

[0032] When Q ri ≤ Q ri1 , determine that the i-th sub-reaction zone of the r-th reaction zone in the current historical detection period is an air pressure insufficient sub-reaction zone; Q ri1 is the second preset air pressure state value of the i-th sub-reaction zone of the r-th reaction zone;

[0033] The first alarm and display device is used to alarm when there is a clogging warning sub-reaction zone and / or an air pressure insufficient sub-reaction zone, and display: the number of the clogging warning sub-reaction zone, the first air pressure state value and the second air pressure state value, the number of the air pressure insufficient sub-reaction zone, the first air pressure state value and the second air pressure state value.

[0034] Preferably, during the mixing process of step S1, a mixing evaluation process is performed periodically. The mixing evaluation process includes:

[0035] Step S10: Detect the temperature of the mixed raw materials in different mixing areas in the mixing device through a temperature detection device; detect the density of the mixed raw materials in different mixing areas in the mixing device through a first density detection device; detect the density of the part of the mixed raw materials in different mixing areas in the mixing device excluding the granular solid catalyst through a second density detection device; detect the viscosity of the mixed raw materials in different mixing areas in the mixing device through a viscosity detection device;

[0036] Step S11: Calculate the actual mixing uneven evaluation value based on the temperature detection device, the first density detection device, the second density detection device, and the viscosity detection device in step S10;

[0037]

[0038] D1 is the mixing uneven evaluation value; T max is the maximum value of the detection values of the temperature detection device in all mixing areas; T min is the minimum value of the detection values of the temperature detection device in all mixing areas; T1 is the standard deviation of the detection values of the temperature detection device in all mixing areas; R max is the maximum value of the detection values of the first density detection device in all mixing areas; R min is the minimum value of the detection values of the first density detection device in all mixing areas; R1 is the standard deviation of the detection values of the first density detection device in all mixing areas; Y maxis the maximum value of the detection values of the viscosity detection device in all mixing regions; Y min is the minimum value of the detection values of the viscosity detection device in all mixing regions; Y1 is the standard deviation of the detection values of the viscosity detection device in all mixing regions; Z max is the maximum value of the detection values of the second density detection device in all mixing regions; Z min is the minimum value of the detection values of the second density detection device in all mixing regions; Z1 is the standard deviation of the detection values of the second density detection device in all mixing regions; μ1, μ2, μ3, and μ4 are the first evaluation weight, the second evaluation weight, and the third evaluation weight, respectively;

[0039] Step S12: When the actual mixing unevenness evaluation value is greater than the preset mixing unevenness evaluation value, control the second alarm to give an alarm.

[0040] Preferably, during the mixing process of step S1, when the second alarm does not give an alarm during the latest mixing evaluation process, perform the first delivery pump regulation process, and the first delivery pump regulation process includes:

[0041] Step S101: Obtain the change curve of the delivery efficiency of the first delivery pump over time between the latest mixing evaluation process and the previous mixing evaluation process;

[0042] Step S102: Obtain the average detection values of all the first density detection devices, all the second density detection devices, and all the viscosity detection devices during the latest mixing evaluation process;

[0043] Step S103: Calculate the target input power of the first delivery pump from the completion of the latest mixing evaluation process to the next mixing evaluation process based on steps S101 and S102.

[0044] Next, through the accompanying drawings and embodiments, the technical solutions of the present invention will be further described in detail.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] The present invention uses a continuous hydrogenation process to produce 1,3-benzenedimethanamine. By using a modified catalyst and adopting a three-phase hydrogenation technology, the catalyst regeneration step is omitted, and hydrogen loss is reduced. Thus, the operation is simplified, the time is shortened, the utilization rate of hydrogen and equipment is improved, and the reactor is easier to control. The advantages of this production process compared with the conventional single-kettle fixed-bed high-pressure operation production are high-quality, low-energy consumption, safe production, and efficient, automated, and uninterrupted operation; the conversion rate of isophthalonitrile is 100%, and the selectivity of 1,3-benzenedimethanamine is above 95%. At the same time, the consumption of the catalyst is reduced.

[0047] During the reaction process of the present invention, monitoring and early warning are carried out based on the air pressure monitoring and early warning module, which is convenient for timely early warning in case of abnormal air pressure, reminding adjustment, so as to ensure that the reaction state of the present invention is more reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention, and do not constitute a limitation to the present invention. In the drawings:

[0049] Figure 1 is a schematic flow chart of the present invention;

[0050] Figure 2 is a gas chromatograph for the content of isophthalonitrile and 1,3-benzenediamine (m-xylylenediamine) in the stock solution after the reaction. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0051] The following describes the preferred embodiments of the present invention with reference to the drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0052] In addition, in the present invention, descriptions such as "first" and "second" are only for descriptive purposes, and do not particularly refer to the order or sequence. Nor are they used to limit the present invention. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions and technical features between various embodiments can be combined with each other, but it must be based on the fact that those skilled in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0053] The present invention provides the following embodiments

[0054] Example 1. The embodiment of the present invention provides a process for continuously producing 1,3-benzenediamine, as Figure 1 shown, including:

[0055] Step S1: After mixing the raw materials and catalysts for producing 1,3-benzenediamine through a mixing device, the mixed raw materials are obtained;

[0056] Step S2: The mixed raw materials are input into the reaction device through the first conveying pipe. A first conveying pump is connected to the first conveying pipe. Hydrogen is input into the reaction device from the hydrogen supply system through the second conveying pipe. The outlets of the first conveying pipe and the second conveying pipe are both connected to the bottom of the reaction device. The raw materials for producing 1,3-benzenedimethanamine react with the catalyst in the reaction device under the push of hydrogen pressure. The top of the reaction device is a separator. The remaining hydrogen after the reaction is separated by the separator and output through the top of the reaction device;

[0057] During step S2, monitoring and early warning are carried out based on the air pressure monitoring and early warning module.

[0058] Preferably, the raw materials for producing 1,3-benzenedimethanamine include: isophthalonitrile, solvent and reaction auxiliary.

[0059] The pressure of the pressurized hydrogen is 2.0 - 6.0 MPa, and the hydrogen in the hydrogen supply system is provided after being compressed by a compressor; the remaining hydrogen after the reaction is separated by the separator and output through the top of the reaction device and also sent to the compressor for compression and recycling;

[0060] In the mixed solution of the isophthalonitrile and the solvent, the weight percentage of isophthalonitrile is 8 - 32%, and the solvent is at least one of methanol, ethanol, toluene, xylene, and water;

[0061] The solvent is 30 - 80% ethanol, 0 - 40% toluene, and 0 - 30% water; the reaction auxiliary is one of sodium hydroxide solution and potassium hydroxide solution, and the addition amount of the auxiliary is 0.05 - 5%;

[0062] The catalyst is a metal skeleton catalyst. This catalyst uses skeletal nickel-aluminum as the main catalyst, introduces at least one element among Pt, Ru, Pd, Cr, Sn, Fe, Cu, Co, and Zn as the co-catalyst, and also includes at least one rare earth metal element among Pt, Ru, Pd, and Sm. The main catalyst, co-catalyst, and rare earth elements are compounded to form a solid heterogeneous catalyst of fine grains of porous nickel-aluminum alloy. The dosage of the main catalyst nickel-aluminum is 95 - 98.5%, the dosage of the co-catalyst is 1 - 5%, the dosage of the rare earth metal is 0 - 0.5%, and the balance is aluminum;

[0063] The process conditions for the three-phase hydrogenation reaction are: temperature 70 - 90 °C, pressure 2 - 6 MPa, weight ratio of solid catalyst to liquid material (raw materials for producing 1,3-benzenedimethanamine) 0.5 - 30%, volume ratio of hydrogen to isophthalonitrile 3 - 15:1, and reaction time 1 - 15 min.

[0064] In the present invention, multiple reaction tubes are arranged in the reaction device. The reaction liquid and H2 are supplied from the bottom of the reaction tubes. The surplus H2 rises along with the reaction liquid in the reaction tubes and reaches the gas-liquid separator (located at the top of the reaction device). During this process, the reaction ends. Therefore, the inside of the reaction tubes is the reaction zone. The formation reaction of MXDA is an exothermic reaction. To eliminate the reaction heat, the outer jacket of the reaction tubes is cooled with cooling water. Since a large amount of hydrogen is in excess, it needs to be recycled. And the flow rate is fast when coming out of the compressor. The inlet at the bottom of the separator is tangential. When the hydrogen and the material flow upward, a negative pressure (siphon effect) is formed at the bottom of the separator, sucking the settled catalyst into the tubular reactor. The separation principle of the separator at the top of the tubular reactor: The gas-solid-liquid materials come up at high speed and enter the separator tangentially. In this way, a vortex is formed in the separator. Due to the different densities of the gas-solid-liquid three phases, the solid with a large density settles in the middle of the vortex. The gas is discharged from the upper part of the separator. After the liquid enters the static area at the lower part of the separator, it is discharged from the sampling outlet, achieving the purpose of gas-solid-liquid separation. The reaction device in the present invention can be referred to CN114671769A.

[0065] The beneficial effects of the above technical solutions are as follows: The present invention uses a continuous hydrogenation process to produce 1,3-benzenedimethanamine. By using a modified catalyst and adopting a three-phase hydrogenation technology, the catalyst regeneration step is omitted and hydrogen loss is reduced. Thus, the operation is simplified, the time is shortened, the utilization rate of hydrogen and equipment is improved, and the reactor is easier to control. The advantages of this production process compared with the conventional single-kettle fixed-bed high-pressure operation production are high-quality, low-energy consumption, safe production, and efficient automatic continuous operation; the conversion rate of isophthalonitrile is 100%, and the selectivity of 1,3-benzenedimethanamine is above 95%. At the same time, the consumption of the catalyst is reduced.

[0066] Moreover, during the reaction process of the present invention, monitoring and early warning are carried out based on the air pressure monitoring and early warning module, which is convenient for timely early warning when the air pressure is abnormal and reminds adjustment, so as to ensure that the reaction state of the present invention is more reliable.

[0067] Example 2, on the basis of Example 1, the catalyst is a granular solid catalyst:

[0068] During step S2, the intelligent hydrogen supply process of the hydrogen supply system includes:

[0069] Step S21: Obtain the standard hydrogen gas pressure corresponding to the currently mixed raw materials that matches the first parameter of the currently mixed raw materials and the target flow rate range of the currently mixed raw materials (which can be obtained based on the preset mapping table of the first parameter of the currently mixed raw materials - the target flow rate range of the currently mixed raw materials - the standard hydrogen gas pressure corresponding to the currently mixed raw materials, or obtained based on the following steps);

[0070] Step S22: Based on the standard hydrogen gas pressure corresponding to the current mixed raw materials, control the hydrogen supply system to supply hydrogen to the reaction device. The present invention can also be provided with a flow rate detection device at the outlet of the first delivery pipe to give an alarm when the detected value of the flow rate detection device is not within the target flow rate range of the corresponding mixed raw materials.

[0071] Optionally, step S21 includes:

[0072] Step S211: Obtain the first parameters of the current mixed raw materials and determine the stacking state parameters of the current mixed raw materials; the first parameters of the current mixed raw materials include: the density of the particulate solid catalyst in the current mixed raw materials; the weight percentage of the particulate solid catalyst in the current mixed raw materials; in the formula of the current mixed raw materials, the density of the other materials after mixing except the particulate solid catalyst; the sum of the weight percentages of the other materials except the particulate solid catalyst in the formula of the current mixed raw materials;

[0073] ρ = A2ρ2 + A1ρ1;

[0074] ρ is the stacking state parameter of the current mixed raw materials, ρ1 is the density of the particulate solid catalyst in the current mixed raw materials; A1 is the weight percentage of the particulate solid catalyst in the current mixed raw materials; ρ2 is the density of the other materials after mixing except the particulate solid catalyst in the formula of the current mixed raw materials; A2 is the sum of the weight percentages of the other materials except the particulate solid catalyst in the formula of the current mixed raw materials;

[0075] Step S212: Obtain the viscosity of the other materials after mixing except the particulate solid catalyst in the formula of the current mixed raw materials (which can be obtained based on detection);

[0076] Step S213: Calculate the standard hydrogen gas pressure corresponding to the current mixed raw materials based on step S211 and step S212;

[0077]

[0078] P is the standard hydrogen gas pressure corresponding to the current mixed raw materials; is the target flow rate range of the current mixed raw materials; S is the cross-sectional area of the outlet of the first delivery pipe, ρ3 is the density of hydrogen; F is the reference required hydrogen driving force for the hydrogenation reaction of the mixed raw materials; d is the particle size of the particulate solid catalyst; δ is the viscosity after mixing of other materials in the current formula of the mixed raw materials except the particulate solid catalyst; θ1 is the angle between the axis of the outlet of the first delivery pipe and the horizontal direction; θ2 is the angle between the axis of the outlet of the second delivery pipe and the horizontal direction; sin is the sine; ρ0 is the reference raw material packing parameter of the mixed raw materials; ln is the natural logarithm.

[0079] The reference required hydrogen driving force for the hydrogenation reaction of the mixed raw materials corresponds to the reference raw material packing parameter of the mixed raw materials. Based on tests, the hydrogen driving force (i.e., the reference required hydrogen driving force for the hydrogenation reaction of the mixed raw materials) that meets the requirements for the hydrogenation reaction effect can be obtained under the reference raw material packing parameter of the mixed raw materials. is the resistance coefficient;

[0080] The beneficial effects of the above technical solution are:

[0081] Based on the first parameter of the current mixed raw materials, determine the current packing state parameter of the mixed raw materials (reflecting the packing density state); based on: the current packing state parameter of the mixed raw materials and the viscosity after mixing of other materials in the current formula of the mixed raw materials except the particulate solid catalyst, calculate the standard hydrogen gas pressure corresponding to the current mixed raw materials, and control the hydrogen supply system to work based on the standard hydrogen gas pressure corresponding to the current mixed raw materials, supply hydrogen to the reaction device, ensure that the hydrogen gas pressure matches the current mixed raw materials, and ensure the hydrogenation reaction effect of the current mixed raw materials.

[0082] The present invention realizes intelligent adjustment of the hydrogen supply pressure of the hydrogen supply system according to different mixed raw materials, ensuring the reliability of hydrogen supply.

[0083] Example 3, based on Example 1 or 2, the air pressure monitoring and warning module includes:

[0084] Air pressure sensors. The reaction area of the reaction device is divided into multiple sub-reaction areas along the hydrogen flow direction. A plurality of air pressure sensors are arranged in each sub-reaction area. During the reaction process, the air pressure sensors detect the air pressure at their locations in real time; each reaction tube in the reaction device is a reaction area; the reaction tube can be a vertical reaction tube, and the reaction tube is divided into multiple sub-reaction areas at intervals up and down.

[0085] Storage module, storing the detection values of the air pressure sensors.

[0086] The first control device, the first alarm and display device, the first timer, and the storage module, where the first control device is electrically connected to the pressure sensor, the first alarm and display device, the first timer, and the storage module respectively.

[0087] The beneficial effects of the above technical solution are as follows: The monitoring and early warning based on the pressure monitoring and early warning module includes: During the reaction in the reaction device, the pressure sensor detects the pressure at its location in real time. When the detected value of the pressure sensor is not within the corresponding preset standard pressure range, the first control device controls the first alarm and display device to alarm and display the number of the pressure sensor whose detected value is not within the corresponding preset standard pressure range. This facilitates the maintenance and adjustment (such as cleaning) of the reaction tube according to the number and detected value of the pressure sensor not within the corresponding preset standard pressure range, or the maintenance and adjustment of the first conveying pipe, or the adjustment of the pressure of the hydrogen supply system.

[0088] Example 4, based on the embodiment 3, the monitoring and early warning based on the pressure monitoring and early warning module includes:

[0089] During the reaction process, at every interval duration, the first control device obtains the detected values of the pressure sensors in the latest historical detection period, and calculates the first pressure state value and the second pressure state value of each sub-reaction zone based on the detected values of the pressure sensors in the latest historical detection period.

[0090]

[0091] E ri is the first pressure state value of the i-th sub-reaction zone in the r-th reaction zone of the latest historical detection period; P ri1 is the average detected value of the pressure sensor in the i-th sub-reaction zone in the r-th reaction zone of the latest historical detection period; P ri0 is the standard pressure of the i-th sub-reaction zone in the r-th reaction zone (the standard pressure is the average pressure of the corresponding sub-reaction zone obtained by testing with the standard hydrogen pressure corresponding to the mixed raw materials in the latest historical detection period when the reaction device and the hydrogen supply system are initially used, to obtain the standard pressure of the sub-reaction zone); Q ri is the second pressure state value of the i-th sub-reaction zone in the r-th reaction zone of the latest historical detection period; P ri+11 is the average detected value of the pressure sensor in the (i + 1)-th sub-reaction zone in the r-th reaction zone of the latest historical detection period; ∈1, ∈2, ∈3, ∈4 are the first pressure evaluation weight (the value is greater than 0 and less than 1, and can be taken as 0.5), the second pressure evaluation weight (the value is greater than 0 and less than 1, and can be taken as 0.5), the third pressure evaluation weight (the value is greater than 0 and less than 1, and can be taken as 0.5), and the fourth pressure evaluation weight (the value is greater than 0 and less than 1, and can be taken as 0.5) respectively;

[0092] When E ri ≥ E ri1 , determine that the i-th sub-reaction area of the r-th reaction area in the current historical detection period is a blocked warning sub-reaction area; E ri1 is the first preset air pressure state value of the i-th sub-reaction area of the r-th reaction area;

[0093] When Q ri ≤ Q ri1 , determine that the i-th sub-reaction area of the r-th reaction area in the current historical detection period is an air pressure insufficient sub-reaction area; Q ri1 is the second preset air pressure state value of the i-th sub-reaction area of the r-th reaction area;

[0094] The first alarm and display device is used to alarm when there is a blocked warning sub-reaction area and / or an air pressure insufficient sub-reaction area, and display: the number of the blocked warning sub-reaction area, the first air pressure state value and the second air pressure state value, the number of the air pressure insufficient sub-reaction area, the first air pressure state value and the second air pressure state value.

[0095] Preferably, the interval duration can be calculated based on the following formula:

[0096]

[0097] where B rj is the duration of the j-th interval duration of the r-th reaction area; B j-1 is the duration of the (j - 1)-th interval duration of the r-th reaction area; max represents the maximum value; Q rij-10 is the second preset air pressure state value of the i-th sub-reaction area of the r-th reaction area calculated for the (j - 1)-th interval duration of the r-th reaction area; E rij-10 is the first preset air pressure state value of the i-th sub-reaction area of the r-th reaction area calculated for the (j - 1)-th interval duration of the r-th reaction area; max represents the maximum value; B1 is the preset duration; min represents the minimum value; the j-th interval duration is after the (j - 1)-th interval duration; is calculated for all sub-reaction areas of the r-th reaction area the minimum value of;

[0098] The duration of the j-th interval duration of the r-th reaction area is the time interval from obtaining the latest historical detection period air pressure sensor detection value of the (j - 1)-th interval duration of the r-th reaction area to obtaining the latest historical detection period air pressure sensor detection value of the r-th reaction area next time.

[0099] The beneficial effects of the above technical solutions are:

[0100] The reaction zone is inside the reaction tube. When the reaction tube is used for a long time, it may be blocked at the position of the sub-region due to the impact and accumulation of materials, resulting in abnormal air pressure in the sub-region; it may also be caused by abnormal hydrogen supply system or abnormal first delivery pipe, resulting in insufficient hydrogen supply pressure, resulting in a significant decrease in the air pressure of some sub-reaction zones.

[0101] The present invention displays the numbers of the blocked warning sub-reaction zones, the first air pressure state values and the second air pressure state values, the numbers of the sub-reaction zones with insufficient air pressure, the first air pressure state values and the second air pressure state values; it is convenient to take targeted treatment measures according to the above display content (such as cleaning the blocked warning sub-reaction zone, and adjusting the hydrogen supply pressure according to the number of the sub-reaction zone with insufficient air pressure).

[0102] Adjust the next interval duration according to the preset air pressure state value two and the preset air pressure state value one of the sub-reaction zone calculated from the previous interval duration to ensure the reliability of the selection of the next interval duration.

[0103] Example 5, on the basis of any one of Examples 1-4, during the mixing process of step S1, a mixing evaluation process is carried out periodically. The mixing evaluation process includes:

[0104] Step S10: Detect the temperature of the mixed raw materials in different mixing areas in the mixing device through a temperature detection device; detect the density of the mixed raw materials in different mixing areas in the mixing device through a first density detection device; detect the density of the part of the mixed raw materials in different mixing areas in the mixing device excluding the granular solid catalyst through a second density detection device; detect the viscosity of the mixed raw materials in different mixing areas in the mixing device through a viscosity detection device;

[0105] Step S11: Calculate the actual mixing uneven evaluation value based on the temperature detection device, the first density detection device, the second density detection device, and the viscosity detection device in step S10;

[0106]

[0107] D1 is the mixing uneven evaluation value; T max is the maximum value of the detection values by the temperature detection device in all mixing areas; T min is the minimum value of the detection values by the temperature detection device in all mixing areas; T1 is the standard deviation of the detection values by the temperature detection device in all mixing areas; R max is the maximum value of the detection values by the first density detection device in all mixing areas; R min is the minimum value of the detection values by the first density detection device in all mixing areas; R1 is the standard deviation of the detection values by the first density detection device in all mixing areas; Y max is the maximum value of the detection values by the viscosity detection device in all mixing areas; Y minis the minimum value of the detection values of the viscosity detection device in all mixing regions; Y1 is the standard deviation of the detection values of the viscosity detection device in all mixing regions; Z max is the maximum value of the detection values of the second density detection device in all mixing regions; Z min is the minimum value of the detection values of the second density detection device in all mixing regions; Z1 is the standard deviation of the detection values of the second density detection device in all mixing regions; μ1, μ2, μ3, μ4 are the first evaluation weight, the second evaluation weight, and the third evaluation weight (all take values greater than 0 and less than 1), respectively;

[0108] Step S12: When the actual mixing unevenness evaluation value is greater than the preset mixing unevenness evaluation value, control the second alarm to give an alarm.

[0109] The beneficial effects of the above technical solution are as follows: During the mixing process of step S1, the mixing evaluation process is carried out periodically, and the temperature of the mixed raw materials, the density of the mixed raw materials, the density of the part of the mixed raw materials excluding the granular solid catalyst, and the viscosity of the mixed raw materials in different mixing regions in the mixing device are detected. Based on the detection results, the actual mixing unevenness evaluation value is determined. When the actual mixing unevenness evaluation value is greater than the preset mixing unevenness evaluation value, control the second alarm to give an alarm to remind to adjust the mixing device, so as to ensure the mixing uniform state; and only when the second alarm does not give an alarm, continue to transport the mixed raw materials to the reaction device through the first delivery pump to ensure the reaction effect.

[0110] Embodiment 6, on the basis of Embodiment 5, during the mixing process of step S1, when the second alarm does not give an alarm during the latest mixing evaluation process, carry out the first delivery pump regulation process. The first delivery pump regulation process includes:

[0111] Step S101: Obtain the change curve of the delivery efficiency of the first delivery pump with time (the abscissa is time, the ordinate is the delivery efficiency of the delivery pump, and the delivery efficiency of the delivery pump is the ratio of the output power to the input power of the delivery pump) between the latest mixing evaluation process and the previous mixing evaluation process;

[0112] Step S102: Obtain the average detection values of all the first density detection devices, all the second density detection devices, and all the viscosity detection devices during the latest mixing evaluation process;

[0113] Step S103: Calculate the target input power of the first delivery pump from the completion of the latest mixing evaluation process to the next mixing evaluation process based on Step S101 and Step S102;

[0114]

[0115] U is the target input power of the first delivery pump when the latest hybrid evaluation process is completed until the next hybrid evaluation process; A is the average detection value of all the first density detection devices calculated in the latest step S101; g is the acceleration due to gravity; S is the cross-sectional area of the outlet of the first delivery pipe; H is the average head of the first delivery pump between the latest hybrid evaluation and the previous hybrid evaluation; is the minimum value of the target flow rate range of the currently mixed raw materials; is the minimum delivery efficiency of the change curve of the delivery efficiency of the first delivery pump with time obtained in the latest step S101; t is the time interval from the completion of the latest hybrid evaluation to the next hybrid evaluation; K1 is the absolute value of the maximum slope of the change curve of the delivery efficiency of the first delivery pump with time obtained in the latest step S101; ρ 11 is the average detection value of all the second density detection devices obtained in step S101 of the previous hybrid evaluation process; δ1 is the average detection value of all the viscosity detection devices obtained in step S101 of the previous hybrid evaluation process; ρ 12 is the average detection value of all the second density detection devices obtained in step S101 of the latest hybrid evaluation process; δ2 is the average detection value of all the viscosity detection devices obtained in step S101 of the latest hybrid evaluation process; ∈ is the difference between the absolute value of the maximum slope and the absolute value of the minimum slope of the change curve of the delivery efficiency of the first delivery pump with time obtained in the latest step S101; ∈0 is the absolute value of the minimum slope of the change curve of the delivery efficiency of the first delivery pump with time obtained in the latest step S101.

[0116] can be the target output power of the first delivery pump when the latest hybrid evaluation process is completed until the next hybrid evaluation process;

[0117] The beneficial effects of the above technical solution are: and only when the second alarm does not alarm, the mixed raw materials are continuously delivered to the reaction device through the first delivery pump to ensure the reaction effect.

[0118] And based on: the change curve of the delivery efficiency of the first delivery pump with time between the latest hybrid evaluation process and the previous hybrid evaluation process, obtain the average detection value of all the first density detection devices, the average detection value of all the second density detection devices, and the average detection value of all the viscosity detection devices in the latest hybrid evaluation process, and calculate the target input power of the first delivery pump when the latest hybrid evaluation process is completed until the next hybrid evaluation process, to ensure the reliable delivery of the mixed raw materials when the latest hybrid evaluation process is completed until the next hybrid evaluation process, and ensure that the flow rate of the mixed raw materials at the outlet of the first delivery pipe meets the requirements.

[0119] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A process for producing 1,3-phenylenediamine by a continuous process, characterized in that: include: Step S1: mixing the raw material for producing 1,3-phenylenediamine and the catalyst through a mixing device to obtain a mixed raw material; Step S2: the mixed raw materials are input into the reaction device through a first delivery pipe, the first delivery pipe is connected to a first delivery pump, hydrogen is input into the reaction device from a hydrogen supply system through a second delivery pipe, the outlets of the first delivery pipe and the second delivery pipe are both connected to the bottom of the reaction device, the raw materials for producing 1,3-phenylenediamine react with the catalyst in the reaction device under the pressure of hydrogen, the top of the reaction device is a separator, and the remaining hydrogen after the reaction is separated by the separator and then output through the top of the reaction device; During step S2, monitoring and warning are performed based on the air pressure monitoring and warning module.

2. A process for producing 1,3-phenylenediamine by a continuous process according to claim 1, characterized in that: The raw materials for producing 1,3-phenylenediamine include isophthalonitrile, solvent and reaction aid.

3. A process for producing 1,3-phenylenediamine by a continuous process according to claim 1, characterized in that: The catalyst is a granular solid catalyst: In step S2, the intelligent hydrogen supply process of the hydrogen supply system includes: Step S21: obtaining a standard hydrogen pressure corresponding to the current mixed raw material that matches the first parameter of the current mixed raw material and the target flow rate range of the current mixed raw material; Step S22: Based on the standard hydrogen pressure corresponding to the current mixed raw materials, the hydrogen supply system is controlled to supply hydrogen to the reaction device.

4. A process for producing 1,3-phenylenediamine by a continuous process according to claim 3, characterized in that: Step S21 includes: Step S211: obtaining the first parameter of the current mixed raw material, and determining the current mixed raw material stacking state parameter; the first parameter of the current mixed raw material includes: the density of the granular solid catalyst in the current mixed raw material; the weight percentage of the granular solid catalyst in the current mixed raw material; the density of the mixed materials other than the granular solid catalyst in the current mixed raw material formula; the sum of the weight percentages of the other materials other than the granular solid catalyst in the current mixed raw material formula; ρ=A2ρ2+A1ρ1; ρ is the current mixed raw material stacking state parameter, ρ1 is the density of the granular solid catalyst in the current mixed raw material; A1 is the weight percentage of the granular solid catalyst in the current mixed raw material; ρ2 is the density of the other materials in the current mixed raw material formula except the granular solid catalyst after mixing; A2 is the sum of the weight percentages of the other materials in the current mixed raw material formula except the granular solid catalyst; Step S212: obtaining the viscosity of other materials in the current mixed raw material formula except the granular solid catalyst after mixing; Step S213: Calculate the standard hydrogen pressure corresponding to the current mixed raw materials based on step S211 and step S212; P is the standard hydrogen pressure corresponding to the current mixed raw materials; is the minimum value of the target flow rate range of the current mixed raw material; S is the cross-sectional area of ​​the outlet of the first delivery pipe, ρ3 is the density of hydrogen; F is the baseline hydrogen driving force required for the hydrogenation reaction of the mixed raw material; d is the particle size of the granular solid catalyst; δ is the viscosity of the other materials in the current mixed raw material formula except the granular solid catalyst after mixing; θ1 is the angle between the axis of the outlet of the first delivery pipe and the horizontal direction; θ2 is the angle between the axis of the outlet of the second delivery pipe and the horizontal direction; sin is sine; ρ0 is the baseline raw material stacking parameter of the mixed raw material; ln is the natural logarithm.

5. The process for producing 1,3-phenylenediamine by a continuous process according to claim 1, characterized in that: The air pressure monitoring and warning module includes: Air pressure sensor: the reaction area of ​​the reaction device is divided into multiple sub-reaction areas along the flow direction of hydrogen, and each sub-reaction area is provided with multiple air pressure sensors. During the reaction process, the air pressure sensor detects the air pressure at its location in real time; A storage module for storing the detection value of the air pressure sensor; A first control device, a first alarm and display device, a first timer, and a storage module. The first control device is electrically connected to the air pressure sensor, the first alarm and display device, the first timer, and the storage module respectively.

6. A process for continuously producing 1,3-phenylenediamine according to claim 5, characterized in that: Monitoring and early warning based on the air pressure monitoring and early warning module include: During the reaction process, at intervals, the first control device obtains the latest pressure sensor detection value of the historical detection period, and calculates the first pressure state value of each sub-reaction area and the second pressure state value of each sub-reaction area based on the latest pressure sensor detection value of the historical detection period; E ri is the first gas pressure state value of the ith sub-reaction zone of the rth reaction zone in the latest historical detection period; P ri1 is the average detection value of the air pressure sensor of the ith sub-reaction zone of the rth reaction zone during the latest historical detection period; P ri0 is the standard pressure of the ith sub-reaction zone of the rth reaction zone; Q ri is the second gas pressure state value of the ith sub-reaction zone of the rth reaction zone in the latest historical detection period; P r(i+1)1 is the average detection value of the air pressure sensor of the i+1th sub-reaction zone of the rth reaction zone in the latest historical detection period; ∈1, ∈2, ∈3, ∈4 are the first air pressure evaluation weight, the second air pressure evaluation weight, the third air pressure evaluation weight, and the fourth air pressure evaluation weight respectively; When E ri ≥E ri1 , determine the i-th sub-reaction area of ​​the r-th reaction area in the current historical detection period as the congestion warning sub-reaction area; E ri1 The preset gas pressure state value of the i-th sub-reaction zone of the r-th reaction zone is one; When Q ri ≤Q ri1 , determine that the i-th sub-reaction zone of the r-th reaction zone in the current historical detection period is the sub-reaction zone with insufficient gas pressure; Q ri1 is the preset gas pressure state value 2 of the i-th sub-reaction zone of the r-th reaction zone; The first alarm and display device is used to give an alarm when there is a blockage warning sub-reaction area and / or an insufficient air pressure sub-reaction area, and to display: the number of the blockage warning sub-reaction area, the first air pressure state value and the second air pressure state value, and the number of the insufficient air pressure sub-reaction area, the first air pressure state value and the second air pressure state value.

7. A process for continuously producing 1,3-phenylenediamine according to claim 6, characterized in that: The interval duration is calculated based on the following formula: Among them, B rj is the duration of the jth interval of the rth reaction zone; B j-1 is the duration of the j-1th interval of the rth reaction zone; max represents the maximum value; Q ri(j-1)0 The preset gas pressure state value 2 of the i-th sub-reaction zone of the r-th reaction zone calculated for the j-1-th interval duration of the r-th reaction zone; E ri(j-1)0 The preset gas pressure state value of the i-th sub-reaction zone of the r-th reaction zone calculated for the j-1-th interval duration of the r-th reaction zone is one; max represents the maximum value; B1 is the preset duration; min represents the minimum value; the j-th interval duration is after the j-1-th interval duration.

8. The process for producing 1,3-phenylenediamine by a continuous process according to claim 1, characterized in that: In the mixing process of step S1, a mixing evaluation process is performed periodically, and the mixing evaluation process includes: Step S10: detecting the temperature of the raw materials mixed in different mixing zones in the mixing device by a temperature detection device; detecting the density of the raw materials mixed in different mixing zones in the mixing device by a first density detection device; detecting the density of the part of the raw materials mixed in different mixing zones in the mixing device except the particulate solid catalyst by a second density detection device; detecting the viscosity of the raw materials mixed in different mixing zones in the mixing device by a viscosity detection device; Step S11: calculating the actual uneven mixing evaluation value based on the temperature detection device, the first density detection device, the second density detection device, and the viscosity detection device in step S10; D1 is the uneven mixing evaluation value; T max is the maximum value of the temperature detection device in all mixed areas; T min is the minimum value of the temperature detection device in all mixed areas; T1 is the standard deviation of the temperature detection device in all mixed areas; R max is the maximum value of the detection value of the first density detection device in all mixed areas; R min is the minimum value of the detection values ​​of the first density detection device in all mixed areas; R1 is the standard deviation of the detection values ​​of the first density detection device in all mixed areas; Y max Y is the maximum value of the viscosity detection device in all mixed areas; min is the minimum value of the viscosity detection device in all mixed areas; Y1 is the standard deviation of the viscosity detection device in all mixed areas; Z max is the maximum value of the detection value of the second density detection device in all mixed areas; Z min is the minimum value of the detection values ​​of the second density detection device in all mixed areas; Z1 is the standard deviation of the detection values ​​of the second density detection device in all mixed areas; μ1, μ2, μ3, and μ4 are the first evaluation weight, the second evaluation weight, and the third evaluation weight, respectively; Step S12: When the actual uneven mixing evaluation value is greater than the preset uneven mixing evaluation value, the second alarm is controlled to sound an alarm.

9. The process for producing 1,3-phenylenediamine by a continuous process according to claim 8, characterized in that: In the mixing process of step S1, when the second alarm does not sound an alarm in the latest mixing evaluation process, the first delivery pump control process is performed, and the first delivery pump control process includes: Step S101: obtaining a curve of a change in the delivery efficiency of a first delivery pump over time between the latest mixing evaluation process and the previous mixing evaluation process; Step S102: obtaining the average detection value of all first density detection devices, the average detection value of all second density detection devices, and the average detection value of all viscosity detection devices in the latest mixing evaluation process; Step S103: Calculating the target input power of the first delivery pump when the latest mixing evaluation process is completed to the next mixing evaluation process based on steps S101 and S102; U is the target input power of the first delivery pump when the latest mixing evaluation process is completed to the next mixing evaluation process; A is the average detection value of all first density detection devices calculated in the latest step S101; g is the acceleration of gravity; S is the cross-sectional area of ​​the outlet of the first delivery pipe; H is the average head of the first delivery pump between the latest mixing evaluation and the previous mixing evaluation; is the minimum value of the target flow rate range of the current mixed raw materials; is the minimum delivery efficiency of the curve of the delivery efficiency of the first delivery pump obtained in the latest step S101 over time; t is the time interval from the latest completion of the mixing evaluation to the next mixing evaluation; K1 is the absolute value of the maximum slope of the curve of the delivery efficiency of the first delivery pump obtained in the latest step S101 over time; ρ 11 is the average detection value of all the second density detection devices obtained in step S101 of the previous mixed evaluation process; δ1 is the average detection value of all the viscosity detection devices obtained in step S101 of the previous mixed evaluation process; ρ 12 is the average detection value of all the second density detection devices obtained in step S101 of the latest mixing evaluation process; δ2 is the average detection value of all the viscosity detection devices obtained in step S101 of the latest mixing evaluation process; ∈ is the difference between the maximum slope absolute value and the minimum slope absolute value of the curve of the change of the delivery efficiency of the first delivery pump over time obtained in the latest step S101; ∈0 is the minimum slope absolute value of the curve of the change of the delivery efficiency of the first delivery pump over time obtained in the latest step S101.

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