Vertical homogeneous reactor and oxamide production system using same
By controlling the liquid-phase reaction rate of oxalate esters and ammonia in a vertical homogeneous reactor, the problems of equipment blockage and ammonia waste in oxamide production were solved, achieving efficient and low-cost oxamide production.
Patent Information
- Application Number
- CN202520121444.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-17
- Publication Date
- 2026-02-13
- Estimated Expiration
- 2035-01-17
AI Technical Summary
In the existing oxalamide production process, the reaction between oxalate esters and ammonia can easily lead to equipment blockage and ammonia waste, and the reaction rate is too fast to control.
A vertical homogeneous reactor is used. By setting up first and second liquid material inlet pipes, dimethyl oxalate and ammonia are both in the liquid phase. Combined with a stirring unit and heat exchange jacket, the reaction rate is controlled and the residence time of the materials in the reactor is extended to avoid solid oxalamide clogging the pipes.
It has achieved efficient production of oxamide, with a raw material utilization rate of 100%, avoiding equipment blockage, reducing ammonia waste, and reducing production costs by recycling and reusing solvents.
Smart Images
Figure CN223901841U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the field of oxamide production, and specifically relates to a vertical homogeneous reactor and an oxamide production system using the same. BACKGROUND
[0002] Oxamide is a kind of slow-release nitrogen fertilizer with excellent performance. The molecular weight is 88.07, the nitrogen content is 31.8%, it is white powder, it is not hygroscopic in air, non-toxic, easy to store, the solubility in water is 0.016%, ammonia nitrogen and carbon dioxide are gradually released in the process of hydrolysis or biodegradation, and it is used as the nitrogen nutrient source for plant growth, and the nitrogen utilization rate is as high as 65%-80%. Compared with the current quick-acting fertilizer such as carbon ammonium, sulfur ammonium and urea, it has the advantages of high fertilizer efficiency, small pollution and long fertilizer efficiency period. At present, the synthesis of oxamide mainly includes hydrocyanic acid method, ammonium oxalate pyrolysis method and oxalate method. In recent years, with the gradual development of the chemical industry, the coal gasification CO synthesis oxalic acid dimethyl ester preparation ethylene glycol technology has achieved breakthrough and large-scale application, the cost of oxalic acid dimethyl ester has been greatly reduced, and the synthesis of oxamide by ammonolysis of oxalic acid dimethyl ester has become the mainstream choice. The oxalate method mainly uses the ammonolysis reaction of oxalate to generate oxamide and the corresponding alcohol. In the actual production process, oxalic acid dimethyl ester methanol solution and ammonia gas are often used for reaction. After the excess ammonia gas and oxalic acid dimethyl ester are fully reacted, oxamide is produced. The above reaction process has the characteristics of fast speed and intense heat release, and oxamide is solid, so it is easy to cause the defects of equipment and pipeline blockage. At the same time, a large amount of ammonia gas is wasted. CONTENT OF THE UTILITY MODEL
[0003] In order to make up for the above shortcomings, the utility model provides a vertical homogeneous reactor and an oxamide production system using the same to solve the technical problems existing in the prior art.
[0004] The utility model solves the technical problems by adopting the following technical scheme:
[0005] A vertical homogeneous reactor, comprising a reactor shell, a stirring unit for realizing uniform mixing of materials is arranged at the top middle position of the reactor shell, a material outlet pipeline is arranged at one side of the top of the reactor shell, and first and second liquid phase material inlet pipelines are arranged at the bottom of the reactor shell.
[0006] The utility model discloses beneficial effect is: through setting up first liquid phase material import pipeline and second liquid phase material import pipeline can realize make dimethyl oxalate and ammonia gas all be in liquid phase state, further, under the premise of adding solvent can reduce ammonia and oxalate unit area contact concentration, to reach the feature of slowing down the reaction rate, the utility model discloses simultaneously adopts the form of lower part feeding and upper part discharge can make material stay sufficient time in reactor shell, to reach the feature of improving raw material utilization rate and realizing raw material full reaction, and avoid the problem of solid oxamide blocking pipeline.
[0007] Preferably, the reactor shell is externally provided with a heat exchange jacket.
[0008] Preferably, the stirring unit comprises a stirring motor arranged at the top of the reactor shell, the stirring motor is connected with a stirring shaft extending into the reactor shell, and the lower part of the stirring shaft is provided with stirring blades.
[0009] Preferably, the bottom of the reactor shell is provided with a discharge pipeline.
[0010] The utility model discloses still provide a kind of oxamide production system using vertical homogeneous phase reactor, first liquid phase material import pipeline is connected with dimethyl oxalate methanol solution production unit, second liquid phase material import pipeline is connected with methanol ammonia solution production unit, material outlet pipeline is connected with flash evaporator, the liquid phase outlet of flash evaporator is connected with centrifuge, and the solid phase outlet of centrifuge is connected with oxamide storage tank through dryer.
[0011] Preferably, the dimethyl oxalate methanol solution production unit comprises an oxalate storage tank and a methanol storage tank, the oxalate storage tank is connected with the inlet of oxalate methanol solution preparation kettle through a metering scale, the methanol storage tank is connected with the inlet of the oxalate methanol solution preparation kettle, and the outlet of the oxalate methanol solution preparation kettle is connected with the first liquid phase material import pipeline.
[0012] Preferably, the methanol ammonia solution production unit comprises a liquid ammonia storage tank, the liquid ammonia storage tank is connected with the inlet of a mixer, the methanol storage tank is connected with the inlet of the mixer, the outlet of the mixer is connected with the second liquid phase material import pipeline through a methanol ammonia buffer tank.
[0013] Preferably, the gas phase outlet of the flash evaporator is connected with the inlet of a methanol recycling storage tank through a flash gas condenser, the outlet of the methanol recycling storage tank is connected with the inlet of the mixer.
[0014] Preferably, the gas phase outlet of the dryer is connected with the inlet of the methanol recycling storage tank through a drying gas condenser.
[0015] Preferably, the liquid phase outlet of the centrifuge is connected with the inlet of the oxalate methanol solution preparation kettle through a centrifugal mother liquor storage tank and a centrifugal mother liquor recycling tank.
[0016] The utility model has the advantages of the following:
[0017] 1, the utility model adopts the form that liquid phase raw material enters the reactor shell and carries out the reaction, reduces the contact concentration of ammonia and oxalate per unit area under the premise of adding solvent, to reach the characteristics of slowing down the reaction rate, based on the above characteristics, the utility model discloses a heat exchange jacket can remove the reaction heat in time, so as to reach the characteristics of controlling the temperature in the reactor shell and realizing its continuous reaction.
[0018] 2, the utility model adopts the form of lower feeding and upper discharging, which can make the material stay in the reactor shell for sufficient time, to reach the characteristics of improving raw material utilization and realizing full reaction of raw materials, the conversion rate of raw materials can reach 100%, and the reactor shell is full of materials when discharging, which can avoid solid oxamide from blocking the pipeline.
[0019] 3, the utility model discloses a stirring unit, which can realize uniform temperature in the reactor shell and avoid local temperature being too high, and also can make the generated oxamide solid uniformly distributed in the liquid phase and avoid the phenomenon of material sticking to the inner wall of the reactor shell.
[0020] 4, the utility model discloses a oxamide production system matched with the vertical homogeneous phase reactor, which can dissolve oxalate and ammonia in methanol to realize the production of oxamide, and also can realize the recycling of methanol and mother liquor, so as to realize the characteristics of reducing production cost, further, the vertical homogeneous phase reactor and the matched oxamide production system can realize the continuous production of oxamide. BRIEF DESCRIPTION OF DRAWINGS
[0021] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description, obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained without creative labor under the premise of these drawings.
[0022] Figure 1 It is the structure schematic drawing of the vertical homogeneous phase reactor of the utility model;
[0023] Figure 2 It is the structure schematic drawing of the oxamide production system of the utility model.
[0024] In the figure: 1, methanol ammonia buffer tank; 2, oxalate methanol solution preparation kettle; 3, reactor shell; 4, flash evaporator; 5, centrifuge; 6, dryer; 7, oxamide storage tank; 8, flash gas condenser; 9, centrifugal mother liquor storage tank; 10, dry gas condenser; 11, methanol reuse storage tank; 12, centrifugal mother liquor reuse tank; 13, liquid ammonia storage tank; 14, mixer; 15, oxalate storage tank; 16, metering scale; 17, methanol storage tank; 18, material outlet pipeline; 19, first liquid phase material inlet pipeline; 20, second liquid phase material inlet pipeline; 21, heat exchange jacket; 22, stirring motor; 23, stirring shaft; 24, stirring blade; 25, discharge pipeline. DETAILED DESCRIPTION
[0025] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0026] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. Figure 1To make further detailed description of the application, a vertical homogeneous phase reactor, including reactor shell 3, the top of the reactor shell 3 is provided with a stirring unit for realizing the uniform mixing of materials, the top of the reactor shell 3 is provided with material outlet pipe 18, the bottom of the reactor shell 3 is provided with first liquid phase material inlet pipe 19 and second liquid phase material inlet pipe 20 respectively. The utility model is used for oxamide production, wherein the first liquid phase material inlet pipe 19 and the second liquid phase material inlet pipe 20 are used for entering liquid phase material, namely oxalate methanol solution and methanol ammonia solution, under the premise that raw materials appear in liquid phase form and methanol solvent is used, the contact concentration of ammonia and oxalate per unit area can be reduced, so as to slow down the reaction rate; the controllable temperature of the reactor shell 3 inside can be realized by slowing down the reaction rate, so as to realize the purpose of continuously and stably producing oxamide; the stirring unit in the utility model can be a conventional stirring structure, which can promote the uniform mixing of oxalate methanol solution and methanol ammonia solution, realize the continuous and stable reaction, and realize the uniform temperature of the solution, avoiding the local high temperature; the first liquid phase material inlet pipe 19 and the second liquid phase material inlet pipe 20 are arranged at the bottom of the reactor shell 3, and the material outlet pipe 18 is arranged at the top of the reactor shell 3, which can make the material stay in the reactor shell 3 for a long time, so as to realize the full reaction of the materials and improve the utilization rate of raw materials; further, when the solution after reaction is large and fills the inside of the reactor shell 3, the solution enters the material outlet pipe 18 by its own pressure and is discharged; the utility model is a continuous production device, so the material in the reactor shell 3 is in a full state, and a large amount of solution can dilute the heat generated by the reaction in time, so as to realize the controllable temperature of the reactor shell 3.
[0027] Further, the reactor shell 3 is provided with a heat exchange jacket 21. As the oxamide synthesis reaction proceeds, the material in the reactor shell 3 gradually warms up, and the heat exchange jacket 21 can remove the reaction heat in time, so as to better control the temperature of the reactor shell 3.
[0028] Further, the stirring unit includes a stirring motor 22 arranged at the top of the reactor shell 3, the stirring motor 22 is connected with a stirring shaft 23 extending into the reactor shell 3, and the lower part of the stirring shaft 23 is provided with stirring blades 24. The above-mentioned arrangement can make the generated oxamide solid uniformly distributed in the liquid phase, avoid the phenomenon of material sticking to the inner wall of the reactor shell, and realize the purpose of convenient discharge.
[0029] Further, the bottom of the reactor shell 3 is provided with a discharge pipe 25. The discharge pipe 25 can timely discharge the material in the reactor shell 3 when the device is stopped.
[0030] Reference Figure 1 、 2 The utility model also provides a kind of oxamide production system using vertical homogeneous reactor, the first liquid phase material import pipeline 19 is connected with oxalic acid dimethyl ester methanol solution production unit, second liquid phase material import pipeline 20 is connected with methanol ammonia solution production unit, material outlet pipeline 18 is connected with flash evaporator 4, the liquid phase outlet of flash evaporator 4 is connected with centrifuge 5, and the solid phase outlet of centrifuge 5 is connected with oxamide storage tank 7 by dryer 6.By the above-mentioned setting, the configuration of oxalic acid dimethyl ester methanol solution and methanol ammonia solution can be realized, and vertical homogeneous reactor is used for the synthesis of oxamide.
[0031] Further, the oxalic acid dimethyl ester methanol solution production unit includes oxalate storage tank 15 and methanol storage tank 17, the oxalate storage tank 15 is connected with the import of oxalate methanol solution preparation kettle 2 by metering scale 16, the methanol storage tank 17 is connected with the import of oxalate methanol solution preparation kettle 2, and the outlet of oxalate methanol solution preparation kettle 2 is connected with the first liquid phase material import pipeline 19.
[0032] Further, the methanol ammonia solution production unit includes liquid ammonia storage tank 13, the liquid ammonia storage tank 13 is connected with the import of mixer 14, the methanol storage tank 17 is connected with the import of mixer 14, and the outlet of mixer 14 is connected with the second liquid phase material import pipeline 20 by methanol ammonia buffer tank 1.
[0033] Further, the gas phase outlet of flash evaporator 4 is connected with the import of methanol reuse storage tank 11 by flash gas condenser 8, and the outlet of methanol reuse storage tank 11 is connected with the import of mixer 14.By the above-mentioned setting, methanol and unreacted ammonia can be recycled and reused.
[0034] Further, the gas phase outlet of dryer 6 is connected with the import of methanol reuse storage tank 11 by drying gas condenser 10.By the above-mentioned setting, methanol can be recycled and reused to reduce production cost.
[0035] Further, the liquid phase outlet of centrifuge 5 is connected with the import of oxalate methanol solution preparation kettle 2 by centrifugal mother liquor storage tank 9 and centrifugal mother liquor reuse tank 12.By the above-mentioned setting, mother liquor can be recycled and reused to reduce production cost.
[0036] The utility model discloses a working principle for: step one: the methanol ammonia buffer groove 1 is with the liquid ammonia from liquid ammonia storage tank 13 and with the methanol from methanol storage tank 17 through mixer 14 form certain concentration methanol ammonia solution into methanol ammonia buffer groove 1, and through second liquid phase material import pipeline 20 send into reactor shell 3, the oxalate methanol solution preparation kettle 2 is with the dimethyl oxalate from dimethyl oxalate storage tank 15 and with the methanol from methanol storage tank 17 prepare dimethyl oxalate methanol solution, and through first liquid phase material import pipeline 19 send into reactor shell 3, the concentration of dimethyl oxalate solution is 20%~50%, and the methanol ammonia solution concentration is 15%~25%. The temperature of methanol ammonia buffer groove 1 is 15~25 DEG C, and the pressure is 0.16MPa~0.25MPa. The temperature of oxalate methanol solution preparation kettle 2 is 25~45 DEG C. Step two: the dimethyl oxalate methanol solution in reactor shell 3 and methanol ammonia solution in reactor carry out homogeneous mixing reaction through the stirring of stirring unit, form oxamide methanol suspension, and through material export pipeline 18 send into flash evaporator 4. The temperature in reactor shell 3 is 25~80 DEG C, and the pressure is 0.16MPa~0.25MPa, and the reaction residence time is 10s~15min, and the stirring speed is 100rmp~700rmp. The amount-of-substance ratio of liquid ammonia and dimethyl oxalate is 2~2.7: 1. Step three: the oxamide methanol suspension of step two carries out flash evaporation, and part of methanol and unreacted ammonia gas are condensed into liquid after the flash condenser 8, enter the methanol recycling storage tank 11 and carry out cyclic utilization, and the suspension after flash evaporation enters centrifuge 5 and carries out centrifugal treatment. The pressure of flash evaporator 4 is -0.06~0.09MPa. Step four: the centrifuge 5 is the oxamide and methanol solid-liquid mixture after the flash evaporation of step three carry out separation, and the oxamide solid and centrifugal mother liquor are obtained after separation. The oxamide solid enters the dryer 6 and carries out drying, and the centrifugal mother liquor flows to the centrifugal mother liquor storage tank 9, and finally enters the centrifugal mother liquor recycling tank 12 and carries out cyclic utilization. The solid content in the oxamide solid of centrifuge 5 is 70%~85%. Step five: the dryer 6 is the oxamide solid of step four carries out drying, and the oxamide finished product after drying enters the oxamide storage tank 7. The methanol and a small amount of ammonia are condensed after the drying gas condenser 10, and the condensed liquid enters the methanol recycling storage tank 11 and carries out cyclic utilization. The temperature of drying device 6 is 40~65 DEG C, and the pressure is -0.06~0.09MPa.
[0037] The basic principle, main features and advantages of the present application are shown and described above. Those skilled in the art should understand that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application.
Claims
1. A vertical, homogeneous reactor comprising a reactor housing (3), characterized in that: The reactor shell (3) is provided with a stirring unit in the middle of the top for uniform mixing of the materials, one side of the top of the reactor shell (3) is provided with a material outlet pipeline (18), and the bottom of the reactor shell (3) is provided with a first liquid phase material inlet pipeline (19) and a second liquid phase material inlet pipeline (20) respectively.
2. A vertical homogeneous reactor according to claim 1, characterized in that: The reactor shell (3) is provided with a heat exchange jacket (21) outside.
3. A vertical homogeneous reactor according to claim 1, characterized in that: The stirring unit includes a stirring motor (22) provided at the top of the reactor shell (3), the stirring motor (22) is connected with a stirring shaft (23) extending into the reactor shell (3), and the lower part of the stirring shaft (23) is provided with stirring blades (24).
4. A vertical homogeneous reactor according to claim 1, characterized in that: The bottom of the reactor shell (3) is provided with a discharge pipeline (25).
5. An oxamide production system using the vertical homogeneous reactor according to any one of claims 1 to 4, characterized by: The first liquid phase material inlet pipeline (19) is connected with a dimethyl oxalate methanol solution production unit, the second liquid phase material inlet pipeline (20) is connected with a methanol ammonia solution production unit, the material outlet pipeline (18) is connected with a flash evaporator (4), the liquid phase outlet of the flash evaporator (4) is connected with a centrifuge (5), and the solid phase outlet of the centrifuge (5) is connected with an oxamide storage tank (7) through a dryer (6).
6. An oxamide production system according to claim 5, characterized in that: The dimethyl oxalate methanol solution production unit includes an oxalate ester storage tank (15) and a methanol storage tank (17), the oxalate ester storage tank (15) is connected with the inlet of an oxalate ester methanol solution preparation kettle (2) through a metering scale (16), the methanol storage tank (17) is connected with the inlet of the oxalate ester methanol solution preparation kettle (2), and the outlet of the oxalate ester methanol solution preparation kettle (2) is connected with the first liquid phase material inlet pipeline (19).
7. The oxamide production system of claim 6, wherein: The methanol ammonia solution production unit includes a liquid ammonia storage tank (13), the liquid ammonia storage tank (13) is connected with the inlet of a mixer (14), the methanol storage tank (17) is connected with the inlet of the mixer (14), and the outlet of the mixer (14) is connected with the second liquid phase material inlet pipeline (20) through a methanol ammonia buffer tank (1).
8. The oxamide production system of claim 7, wherein: The gas phase outlet of the flash evaporator (4) is connected with the inlet of a methanol recycling storage tank (11) through a flash gas condenser (8), and the outlet of the methanol recycling storage tank (11) is connected with the inlet of the mixer (14).
9. The oxamide production system of claim 8, wherein: The gas phase outlet of the dryer (6) is connected with the inlet of the methanol recycling storage tank (11) through a drying gas condenser (10).
10. The oxamide production system of claim 6, wherein: The liquid phase outlet of the centrifuge (5) is connected with the inlet of the oxalate ester methanol solution preparation kettle (2) through a centrifugal mother liquor storage tank (9) and a centrifugal mother liquor recycling tank (12).