Ammoniation reaction device in glycine production process
By introducing a pre-reaction vessel and a main reaction vessel into glycine production, and carrying out the ammoniation reaction in steps, the problems of small heat exchange area and low catalyst concentration caused by low liquid level in traditional glycine production are solved, achieving efficient glycine production, improving yield and capacity, and simplifying equipment modification.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- FUHUA TONGDA CHEM CO LTD
- Filing Date
- 2025-04-23
- Publication Date
- 2026-05-15
AI Technical Summary
In traditional glycine production, the ammoniation reaction results in a small heat exchange area due to the low initial liquid level, making it difficult to control the reaction temperature. This leads to long reaction time, low production capacity, and low yield. Existing improvement methods, such as diluting the catalyst or increasing the water volume, reduce the catalyst concentration and affect the yield.
In the glycine production process, a pre-reaction vessel and a main reaction vessel are introduced. By increasing the liquid level and heat exchange area in the pre-reaction vessel, the ammoniation reaction is carried out in steps, ensuring a high liquid level and a high catalyst concentration, reducing side reactions, and improving heat exchange efficiency.
It effectively controls reaction temperature, shortens reaction time, increases glycine yield and production capacity, simplifies automated control systems, reduces raw material consumption, is suitable for upgrading old equipment, and has high engineering value.
Smart Images
Figure CN224236788U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of glycine production and preparation technology, and in particular to an ammoniation reaction device in the glycine production process. Background Technology
[0002] my country is currently a major consumer of glycine, with its industrial-grade glycine consumption ranking first globally. This is primarily because most of my country's glyphosate production processes utilize the alkylation method with glycine as a raw material. Traditional glycine production involves using hexamethylenetetramine as a catalyst, chloroacetic acid and ammonia as raw materials, followed by the addition of methanol to crystallize and obtain solid glycine.
[0003] Ammoniation is a key regulated process, and it is inherently exothermic. Traditional ammoniation uses an aqueous solution of hexamethylenetetramine as the substrate, with ammonia gas introduced simultaneously as chloroacetic acid is added. This is typically a batch reaction in a reactor, with a heat exchange jacket installed outside the reactor to remove heat generated and control the reaction temperature within a suitable range. Due to the inherent characteristics of the reaction, converting it to a continuous reaction can easily lead to a decrease in yield. This is because, within a certain range, catalyst concentration is positively correlated with reaction yield. The typical continuous reaction mode results in a low catalyst concentration, naturally leading to a lower reaction yield.
[0004] Currently, most companies still use batch reactors to produce glycine. However, since the catalyst is generally dissolved in the reaction system and is inconvenient to recover, in order to reduce production costs, the amount of catalyst used is minimized while meeting the most basic requirements of the reaction. At the beginning of the reaction, the catalyst is added to the reactor all at once, and chloroacetic acid is added dropwise. The current situation is: (1) At the beginning of the reaction, the initial liquid level in the reactor is low (there is only catalyst in the reactor, and the amount of catalyst is only 1 / 6 of the volume of the reactants after the reaction is completed. The raw material chloroacetic acid is added dropwise, and the amount added at the beginning of the reaction is small), which makes the heat exchange area between the reactants in the reactor and the heat exchanger small. As the reaction proceeds, the raw material chloroacetic acid is gradually added dropwise into the reactor, and the liquid level in the reactor gradually rises, and the heat exchange area gradually increases. Therefore, when the reaction liquid level is low at the beginning of the reaction, it is not convenient to control the temperature in the reactor. In order to maintain the reaction temperature, the feeding rate of chloroacetic acid is slow at the beginning of the reaction and fast at the end, which also leads to a long total reaction time and difficulty in temperature control, resulting in an increase in side reactions. This not only results in low production capacity but also low yield.
[0005] (2) In order to solve the problem of the initial liquid level of the reactor being too low and the heat exchange area being too small, and at the same time to avoid increasing the amount of catalyst, the common method in the prior art is to continue to add water to the hexamethylenetetramine solution to increase the initial liquid level of the reactor and increase the initial heat exchange area. Although this can shorten the feeding rate of chloroacetic acid, the reaction yield will also decrease due to the reduction in catalyst concentration.
[0006] The invention patent with publication number CN111187173B discloses a continuous method for synthesizing glycine, including the following steps: preparing ammonia water; then mixing chloroacetic acid solution and ammonia water to undergo a salt-forming reaction to obtain solution A; adding a mixed solution containing hexamethylenetetramine and ammonia water in multiple portions to solution A to undergo an ammoniation reaction, followed by cooling, crystallization, and separation to obtain mixed crystals of glycine and ammonium chloride and a mixed crystal mother liquor; using the mixed crystal mother liquor as a solvent to prepare the ammonia water in step (1) or the chloroacetic acid solution in step (2); continuing the above reaction to achieve continuous glycine synthesis. This invention breaks down the original one-step process into three parts: "ammonia dissolution," "salt-forming reaction," and "ammoniation reaction," so that ammonia water can be uniformly mixed with the feed solution in the required amount, avoiding the problem of excessive by-products caused by local overheating of ammonia absorption or excessively high pH of the feed solution in some areas, effectively avoiding the defects of conventional process methods, improving the glycine yield, and reducing hexamethylenetetramine consumption.
[0007] However, this patent mixes chloroacetic acid and ammonia water to generate ammonium chloroacetate in the absence of a catalyst. At the same time, the pH increases, and the ammoniation reaction is not carried out in time. This easily causes some chloroacetic acid to hydrolyze into glycolic acid. In addition, the solubility of ammonium chloroacetate is lower than that of chloroacetic acid, which requires more water. The utilization rate of the reaction vessel is low, and the catalyst concentration is low, resulting in a low actual reaction yield. Utility Model Content
[0008] This invention aims to provide an ammoniation reaction device in the production of glycine. By adding a pre-reaction vessel to the existing glycine synthesis reactor, the material level in the reactor can be increased at the beginning of the reaction, thereby increasing the average liquid level of the material in the reactor during the reaction process. This increases the average heat exchange area of the entire reaction process, thereby improving heat exchange efficiency and effectively reducing the feeding time of chloroacetic acid. It not only ensures a high catalyst concentration, suppresses side reactions, and improves yield, but also effectively increases production capacity, and has extremely high engineering value.
[0009] To achieve the above-mentioned objectives, the technical solution of this utility model is as follows:
[0010] An ammoniation reaction device for glycine production includes a pre-reaction vessel and a main reaction vessel. The top of both the main reaction vessel and the pre-reaction vessel is provided with a feed inlet, a chloroacetic acid dripping port, an ammonia inlet, and a tail gas outlet. The tail gas outlet is connected to a tail gas treatment mechanism. The bottom of both the main reaction vessel and the pre-reaction vessel is provided with a discharge port. The pre-reaction vessel and the main reaction vessel are the same size. The number of main reaction vessels is greater than or equal to the number of pre-reaction vessels. The discharge port of the pre-reaction vessel is connected to the feed inlet of the main reaction vessel through a pipeline.
[0011] The number of main reactors is 1-3 times the number of pre-reactors.
[0012] A transfer vessel is installed on the pipeline between the outlet of the pre-reaction vessel and the inlet of the main reaction vessel. When the reaction times of the main reaction vessel and the pre-reaction vessel are not matched, the reacted material in the pre-reaction vessel is transferred to the transfer vessel for temporary storage. Since the transfer vessel only serves the functions of metering and temporary storage of materials, the correspondence between the transfer vessel, the pre-reaction vessel, and the main reaction vessel can be that multiple pre-reaction vessels correspond to one transfer vessel, and one transfer vessel corresponds to multiple main reaction vessels.
[0013] Both the pre-reaction vessel and the main reaction vessel are jacketed enamel-lined reaction vessels.
[0014] The main reactor and the pre-reaction reactor are equipped with valves at their inlet, outlet, ammonia inlet, and chloroacetic acid droplet.
[0015] The main reactor and the pre-reactor are respectively equipped with an ammonia gas pipeline and a chloroacetic acid pipeline. One end of the ammonia gas pipeline is connected to the ammonia gas inlet, and the other end of the ammonia gas pipeline extends into the bottom of the main reactor or the pre-reactor. One end of the chloroacetic acid pipeline is connected to the chloroacetic acid drip inlet, and the other end of the chloroacetic acid pipeline extends into the bottom of the main reactor or the pre-reactor. Both the ammonia gas pipeline and the chloroacetic acid pipeline extend into the reactants and are introduced into the reaction system from below the liquid surface of the reactants.
[0016] The chloroacetic acid dripping ports of the main reactor and the pre-reaction vessel are connected to chloroacetic acid delivery pumps, which drip chloroacetic acid into the main reactor and the pre-reaction vessel.
[0017] The main reactor and the pre-reactor are equipped with flow meters and regulating valve I at their chloroacetic acid drop inlets; temperature sensors are installed in the main reactor and the pre-reactor respectively; the chloroacetic acid feeding rate is controlled by regulating valve I; the chloroacetic acid feeding rate is determined by the temperature of the reaction process.
[0018] Both the main reactor and the pre-reaction vessel are equipped with pH sensors.
[0019] The ammonia inlet of the main reactor and the pre-reaction vessel is equipped with an ammonia vaporizer, through which ammonia gas is introduced into the main reactor and the pre-reaction vessel;
[0020] The ammonia inlet of the main reactor and the pre-reaction reactor is equipped with a pressure gauge and a regulating valve II. The ammonia feeding rate is controlled by the regulating valve II. The ammonia feeding rate is determined by the pH during the reaction process.
[0021] The beneficial effects of this utility model are:
[0022] 1. In this utility model, by setting up a pre-reaction vessel and a main reaction vessel, the ammoniation reaction is divided into two steps: a pre-reaction and a main reaction. The initial liquid level of the pre-reaction vessel is higher than that of the traditional mode, and the heat exchange area is greatly increased. In the early stage of the reaction, the reaction temperature can be effectively controlled, thereby increasing the dropping rate of chloroacetic acid, reducing the occurrence of side reactions, and achieving the goal of increasing production capacity and yield.
[0023] 2. In this invention, the ratio of the pre-reaction vessel to the main reaction vessel is 1:1 to 1:3. Two to three times the amount of catalyst required for the original batch reaction is added to the pre-reaction vessel to ensure a high liquid level. Then, a portion of chloroacetic acid is added dropwise, and ammonia is introduced for pre-reaction. The pre-reaction liquid is then transferred to a transfer vessel for the next batch of pre-reaction. The pre-reaction liquid is then evenly distributed to 2 to 3 reaction vessels without adding any more catalyst. Chloroacetic acid is added dropwise according to the designed material ratio, and ammonia is introduced to complete the ammoniation reaction. The ammoniation reaction liquid is then pumped into the alcohol precipitation process, and the main reaction vessel can then proceed with the next batch of ammoniation. This method ensures that the materials are kept at a high level during the reaction process, increases the average heat exchange area of the entire reaction process, effectively reduces the chloroacetic acid feeding time, suppresses side reactions, improves yield, and significantly increases production capacity, possessing extremely high engineering value.
[0024] 3. In this invention, the catalyst is added only to the pre-reaction vessel, and no further catalyst is added to the main reaction vessel. This reduces the need for corresponding pipelines, regulating valves, flow meters, etc., simplifies the automated control system, and lowers investment. It also shortens the reaction time, improves reaction efficiency, reduces the occurrence of side reactions, and lowers the consumption of raw materials.
[0025] 4. In this utility model, a common enamel-lined reactor is used as the ammoniation reactor, which can achieve a high ammoniation reaction efficiency. In particular, old equipment can be used for simple modification to increase production capacity. It is very suitable for the technological upgrading of production enterprises and has great engineering value. Attached Figure Description
[0026] Figure 1 This is a schematic diagram of the ammoniation reaction device in the glycine production process of this utility model.
[0027] Among them, 1. Main reactor; 2. Transfer reactor; 3. Pre-reaction reactor; 4. Tail gas treatment mechanism; 5. Chloroacetic acid drip inlet; 6. Ammonia inlet; 7. Tail gas outlet; 8. Ammonia pipeline; 9. Chloroacetic acid pipeline; 10. Flow meter; 11. Control valve I; 12. Pressure gauge; 13. Control valve II. Detailed Implementation
[0028] The present invention will be further described in detail below with reference to the embodiments, but the implementation of the present invention is not limited thereto.
[0029] Example 1
[0030] This embodiment provides a method such as Figure 1 The ammoniation reaction apparatus shown in the glycine production process includes a pre-reaction vessel 3 and a main reaction vessel 1. Both the main reaction vessel 1 and the pre-reaction vessel 3 are equipped with a feed inlet, a chloroacetic acid dripping port 5, an ammonia inlet 6, and a tail gas outlet 7 at their tops. The tail gas outlet 7 is connected to a tail gas treatment mechanism 4. Both the main reaction vessel 1 and the pre-reaction vessel 3 are equipped with discharge ports at their bottoms. The pre-reaction vessel 3 and the main reaction vessel 1 are of the same size. There are two pre-reaction vessels 3 and two main reaction vessels 1. The discharge ports of the two pre-reaction vessels 3 are connected to the feed ports of the two main reaction vessels 1 via pipelines. Both the pre-reaction vessel 3 and the main reaction vessel 1 are jacketed enamel-lined reactors. The main reactor 1 and the pre-reaction vessel 3 are equipped with valves at their inlets, outlets, ammonia inlet 6, and chloroacetic acid droplet 5. Ammonia pipe 8 and chloroacetic acid pipe 9 are respectively installed inside the main reactor 1 and the pre-reaction vessel 3. One end of ammonia pipe 8 is connected to ammonia inlet 6, and the other end extends to the bottom of the main reactor 1 or the pre-reaction vessel 3. One end of chloroacetic acid pipe 9 is connected to chloroacetic acid droplet 5, and the other end extends to the bottom of the main reactor 1 or the pre-reaction vessel 3. Both ammonia pipe 8 and chloroacetic acid pipe 9 extend into the reactants, flowing into the reaction system below the surface of the reactants. A chloroacetic acid delivery pump is connected to the chloroacetic acid droplet 5 of the main reactor 1 and the pre-reaction vessel 3, through which chloroacetic acid is added dropwise into the main reactor 1 and the pre-reaction vessel 3. The ammonia inlet 6 of the main reactor 1 and the pre-reaction vessel 3 is equipped with an ammonia vaporizer, through which ammonia gas is introduced into the main reactor 1 and the pre-reaction vessel 3.
[0031] In this embodiment, by setting up a pre-reaction vessel 3 and a main reaction vessel 1, the ammoniation reaction is divided into two steps: a pre-reaction and a main reaction. A catalyst is added to the pre-reaction vessel 3 as the reaction substrate. The catalyst is a 25% (w / w) aqueous solution of hexamethylenetetramine. The volume ratio of the catalyst to the reactants after the reaction is completed is 1:6.
[0032] In this embodiment, twice the amount of catalyst required for the original batch reactor is added to a pre-reaction vessel 3. The catalyst volume in the pre-reaction vessel 3 is one-third of its volume, ensuring a higher liquid level and a larger heat exchange area within the reactor. Then, some chloroacetic acid is added dropwise, and ammonia gas is introduced for pre-reaction. When the reactants in the pre-reaction vessel 3 are equal to its volume,
[0033] After the chloroacetic acid is added, the pH of the material no longer decreases when ammonia gas is no longer introduced, indicating that the pre-reaction is complete. The reaction liquid in the pre-reaction vessel 3 is transferred to the main reaction vessel 1 via a transfer pump. The remaining chloroacetic acid is added dropwise according to the designed material ratio, and ammonia gas is introduced to complete the ammoniation reaction. When the volume of the reactants reaches the same as that of the main reaction vessel 1, the main reaction is judged to be complete when the pH no longer decreases after the chloroacetic acid is added and ammonia gas is no longer introduced.
[0034] The ammoniation reaction solution is then pumped to the subsequent alcohol precipitation process. The main reactor 1 can then proceed with the next batch of ammoniation reactions. This design ensures that the materials are kept at a high level throughout the reaction process, increasing the average heat exchange area and effectively reducing the chloroacetic acid feeding time. This not only suppresses side reactions and improves yield but also significantly increases production capacity. It possesses extremely high engineering value.
[0035] In this embodiment, at the start of the reaction, the two pre-reaction vessels are fed with materials at intervals. The substrate in each pre-reaction vessel 3 is 1 / 3 of the reactor volume; the substrate in each main reaction vessel 1 is 1 / 2 of the reactor volume. Therefore, the amount of chloroacetic acid added in each main reaction vessel 1 is more than that in the pre-reaction vessel 3. As a result, the reaction time in the main reaction vessel 1 is shorter than that in the pre-reaction vessel 3. Therefore, the transfer vessel 2 can be omitted, and the material in the pre-reaction vessel 3 can be directly transferred to the main reaction vessel 1 for reaction by a transfer pump.
[0036] In this embodiment, the pre-reaction time is 80 minutes; the main reaction time is 40 minutes. The two pre-reaction vessels 3 are fed with materials at 40-minute intervals. The two pre-reaction vessels are fed at these intervals to coordinate with the two main reaction vessels, ensuring that the reaction times of the pre-reaction vessels 3 and the main reaction vessels 1 are compatible. Both the pre-reaction vessels 3 and the main reaction vessels 1 are modified from old enamel-lined reactors used in batch reactors. In this embodiment, the volume of the enamel-lined reactor is 3 m³. At the beginning of the reaction, 1 m³ of a 25% hexamethylenetetramine aqueous solution is added to the pre-reaction vessel. After the catalyst is added, chloroacetic acid is added dropwise, and excess ammonia is introduced. When the reaction temperature reaches 65-70°C, the jacket cooling water is turned on. When the amount of chloroacetic acid added is 1.5 m³, the reactants in the pre-reaction vessel 3 reach 3 m³. Ammonia is continued to be introduced. When the pH of the material no longer decreases when ammonia is no longer introduced, it indicates that the pre-reaction is complete. The reaction liquid in the pre-reaction vessel 3 is transferred to the main reaction vessel 1 by a transfer pump. According to the designed material ratio, 0.75 m³ of chloroacetic acid is added dropwise to each of the two main reaction vessels 1 until the reaction is completed.
[0037] The yield in this embodiment is 83%. Compared with the original batch reactor, the pre-reaction liquid produced by the alternating reaction of the two main reactors 1 in this embodiment is used as the initial material for the two main reactors 1, which is equivalent to using 4 reactors. Two batches are discharged every 40 minutes, and one batch is discharged every 20 minutes. The original batch reactor takes about 110 minutes per batch. Using 4 reactors is equivalent to discharging one batch every 27.5 minutes. The production efficiency of this embodiment is significantly improved.
[0038] Compared with the original batch reactor, if the batch reactor is further diluted with catalyst to increase the initial liquid level, the production efficiency can reach the level of this embodiment, but the glycine yield can only reach 79%~80%, which is significantly lower than the method used in this embodiment.
[0039] Example 2
[0040] Compared with Example 1, the difference in this embodiment is that there is one pre-reaction vessel 3 and three main reaction vessels 1 in this embodiment, and the rest of the structure is the same as in Example 2.
[0041] In this embodiment, at the initial stage of the reaction, 1.5 m³ of a 25% hexamethylenetetramine aqueous solution was added to the primary reaction vessel. After the catalyst was added, chloroacetic acid was added dropwise while excess ammonia was introduced. When the reaction temperature reached 65-70°C, the jacket cooling water was turned on. When the amount of chloroacetic acid added was 1.125 m³, the reactants in the pre-reaction vessel 3 reached 3 m³. Ammonia was continued to be introduced. When the pH of the material stopped decreasing after the ammonia was stopped, it indicated that the pre-reaction was complete. The reaction liquid in the pre-reaction vessel 3 was transferred to the main reaction vessel 1 via a transfer pump. According to the designed material ratio, 1.125 m³ of chloroacetic acid was added dropwise to each of the three main reaction vessels 1 until the reaction was completed.
[0042] In this embodiment, the reaction time of the pre-reaction was 60 min; the reaction time of the main reaction was 60 min; and the yield was 83%.
[0043] Compared to the original batch reactor, in this embodiment, the pre-reaction liquid produced by one main reactor 1 is used as the initial material for three main reactors 1, which is equivalent to using four reactors. Three batches are discharged every 60 minutes, and one batch is discharged every 20 minutes. The original batch reactor took approximately 110 minutes per batch; using four reactors is equivalent to discharging one batch every 27.5 minutes. This embodiment shows a significant improvement in production efficiency.
[0044] Compared with the original batch reactor, if the batch reactor is further diluted with catalyst to increase the initial liquid level, the production efficiency can reach the level of this embodiment, but the glycine yield can only reach 79%~80%, which is significantly lower than the method used in this embodiment.
[0045] Example 3
[0046] The difference between this embodiment and embodiment 1 is that, in this embodiment, a transfer vessel 2 is installed on the pipeline between the outlet of the pre-reaction vessel 3 and the inlet of the main reaction vessel 1, and the rest of the structure is the same as in embodiment 1.
[0047] In this embodiment, at the initial stage of the reaction, 1 m³ of a 25% hexamethylenetetramine aqueous solution was added to the main reactor. After the catalyst was added, chloroacetic acid was added dropwise while excess ammonia was introduced. When the reaction temperature reached 65-70°C, the jacket cooling water was turned on. When the amount of chloroacetic acid added was 1.5 m³, the reactants in the pre-reaction vessel 3 reached 3 m³. Ammonia was continued to be introduced. When the pH of the material stopped decreasing after the ammonia was stopped, it indicated that the pre-reaction was complete. The reaction liquid in the pre-reaction vessel 3 was transferred to the main reactor 1 via a transfer pump. According to the designed material ratio, 0.75 m³ of chloroacetic acid was added dropwise to each of the three main reactors 1 until the reaction was completed.
[0048] In this embodiment, the reaction time of the pre-reaction was 80 min; the reaction time of the main reaction was 40 min; and the yield was 83%.
[0049] In this embodiment, the two pre-reaction vessels are fed simultaneously at the start of the reaction and the reactions end simultaneously. One batch of pre-reaction liquid is directly and evenly distributed to the two main reaction vessels for further addition of chloroacetic acid. The remaining batch of pre-reaction liquid is temporarily stored in the transfer vessel. After the main reaction is completed, the material in the temporary storage vessel is then evenly distributed to the two main reaction vessels. Since the transfer vessel 2 only serves the functions of metering and temporary material storage, the correspondence between the transfer vessel 2, the pre-reaction vessel 3, and the main reaction vessel 1 can be such that multiple pre-reaction vessels 3 correspond to one transfer vessel 2, and one transfer vessel 2 corresponds to multiple main reaction vessels 1. Furthermore, the pre-reaction vessel requires 80 minutes, but in practice, due to control reasons, fluctuations in cooling water flow, etc., some batches may only take 75 minutes, while other batches may take 85 minutes. In this case, the transfer vessel can also play a role in balancing the pre-reaction and the main reaction.
[0050] In this embodiment, a transfer pump is installed between the pre-reaction vessel 3 and the intermediate vessel 2, and a transfer pump is installed in the connecting pipeline between the intermediate vessel 2 and the main reaction vessel 1. After the reaction in the pre-reaction vessel 3 is completed, the discharge valve of the pre-reaction vessel 3 and the inlet valve of the intermediate vessel 2 are opened, and the material in the pre-reaction vessel 3 is transported to the intermediate vessel 2 by the transfer pump. When it is necessary to transport material to the main reaction vessel 1, the discharge valve of the intermediate vessel 2 and the inlet valve of the main reaction vessel 1 are opened, and the material is transported from the intermediate vessel 2 to the main reaction vessel 1 by the transfer pump for further reaction.
[0051] Compared to the original batch reactor, this embodiment uses the pre-reaction liquid produced by the alternating reactions of the two main reactors 1 as the initial material for both reactors 1. This is equivalent to using four reactors, producing two batches every 40 minutes and one batch every 20 minutes. The original batch reactor took approximately 110 minutes per batch, while using four reactors is equivalent to producing one batch every 27.5 minutes. This embodiment significantly improves production efficiency.
[0052] Compared with the original batch reactor, if the batch reactor is further diluted with catalyst to increase the initial liquid level, the production efficiency can reach the level of this embodiment, but the glycine yield can only reach 79%~80%, which is significantly lower than the method used in this embodiment.
[0053] Example 4
[0054] Compared with Example 1, the difference in this embodiment is that, in this embodiment, the chloroacetic acid dripping port 5 of the main reaction vessel 1 and the pre-reaction vessel 3 is equipped with a flow meter 10 and a regulating valve I11; a temperature sensor is installed in the main reaction vessel 1 and the pre-reaction vessel 3 respectively; a pH sensor is installed in both the main reaction vessel 1 and the pre-reaction vessel 3; and a pressure gauge 12 and a regulating valve II13 are installed in the ammonia gas inlet 6 of the main reaction vessel 1 and the pre-reaction vessel 3. The rest of the structure is the same as in Example 2.
[0055] In this embodiment, the chloroacetic acid delivery pump is a corrosion-resistant centrifugal pump; the flow meter 10 is an electromagnetic flow meter; the regulating valve I11 is a corrosion-resistant ceramic valve; the temperature sensor is a resistance temperature detector (RTD) or thermocouple temperature sensor; the pH sensor is a glass electrode online pH meter; the pressure gauge 12 is a diaphragm pressure gauge; and the regulating valve II13 is a common carbon steel valve. In this embodiment, before the reaction reaches the target reaction temperature of 70-85°C, the material heating rate is controlled at 3-4°C / min by controlling the ammonia addition rate. If the heating rate is slow, the ammonia flow rate is increased; if the heating rate is fast, the ammonia addition rate is decreased. The pH of the material is controlled between 5 and 7 by the chloroacetic acid flow rate. If the pH value is too high, the chloroacetic acid addition rate is increased; if the pH value is too low, the chloroacetic acid addition rate is slowed down. When the temperature reaches the target reaction temperature range, all the cooling water in the jacket is turned on. The reaction temperature is maintained by adjusting the ammonia addition rate, and the pH value of the reactants is maintained by adjusting the chloroacetic acid addition rate.
[0056] It is understood that this utility model has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this utility model. Furthermore, under the teachings of this utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of this utility model.
Claims
1. An ammoniation reaction apparatus for glycine production, characterized in that: The reactor includes a pre-reaction vessel (3) and a main reaction vessel (1). The top of the main reaction vessel (1) and the pre-reaction vessel (3) are respectively provided with a feed inlet, a chloroacetic acid dripping port (5), an ammonia inlet (6) and a tail gas outlet (7). The tail gas outlet (7) is connected to a tail gas treatment mechanism (4). The bottom of the main reaction vessel (1) and the pre-reaction vessel (3) are respectively provided with a discharge port. The pre-reaction vessel (3) and the main reaction vessel (1) are the same size. The number of main reaction vessels (1) is greater than or equal to the number of pre-reaction vessels (3). The discharge port of the pre-reaction vessel (3) is connected to the feed inlet of the main reaction vessel (1) through a pipeline.
2. The ammoniation reaction apparatus in the glycine production process according to claim 1, characterized in that: The number of main reactors (1) is 1-3 times the number of pre-reactors (3).
3. The ammoniation reaction apparatus in the glycine production process according to claim 1, characterized in that: A transfer vessel (2) is installed on the pipeline between the outlet of the pre-reaction vessel (3) and the inlet of the main reaction vessel (1).
4. The ammoniation reaction apparatus in the glycine production process according to claim 2 or 3, characterized in that: Both the pre-reaction vessel (3) and the main reaction vessel (1) are jacketed enamel-lined reaction vessels.
5. The ammoniation reaction apparatus in the glycine production process according to claim 2 or 3, characterized in that: The main reactor (1) and the pre-reactor (3) are respectively equipped with an ammonia gas pipeline (8) and a chloroacetic acid pipeline (9). One end of the ammonia gas pipeline (8) is connected to the ammonia gas inlet (6), and the other end of the ammonia gas pipeline (8) extends to the bottom of the main reactor (1) or the pre-reactor (3). One end of the chloroacetic acid pipeline (9) is connected to the chloroacetic acid dripping port (5), and the other end of the chloroacetic acid pipeline (9) extends to the bottom of the main reactor (1) or the pre-reactor (3).
6. The ammoniation reaction apparatus in the glycine production process according to claim 5, characterized in that: The chloroacetic acid droplet (5) of the main reactor (1) and the pre-reaction reactor (3) are connected to chloroacetic acid delivery pumps.
7. The ammoniation reaction apparatus in the glycine production process according to claim 6, characterized in that: The chloroacetic acid drip inlet (5) of the main reactor (1) and the pre-reaction vessel (3) is equipped with a flow meter (10) and a regulating valve I (11); a temperature sensor is installed in the main reactor (1) and the pre-reaction vessel (3); a pH sensor is installed in both the main reactor (1) and the pre-reaction vessel (3).
8. The ammoniation reaction apparatus in the glycine production process according to claim 5, characterized in that: The ammonia inlet (6) of the main reactor (1) and the pre-reactor (3) is equipped with an ammonia vaporizer.
9. The ammoniation reaction apparatus in the glycine production process according to claim 8, characterized in that: The ammonia inlet (6) of the main reactor (1) and the pre-reactor (3) is equipped with a pressure gauge (12) and a regulating valve II (13).