A production system for recycling methylamine in a production process of sarcosine sodium

Abstract

The utility model relates to a kind of methylamine removal and cyclic recovery production system of sarcosine sodium production process, wherein, including: raw material pretreatment unit, steam unit, first condensing recovery unit and secondary suction condensing unit are sequentially connected;Raw material pretreatment unit is used to pretreat and heat sarcosine sodium reaction liquid;Reaction liquid after raw material pretreatment unit enters steam unit and is heated steam;Gas obtained by steam, enters first condensing recovery unit;First condensing recovery unit condenses part of amine and steam into liquid, and is collected;Secondary suction condensing unit receives the amine gas that is not condensed by first condensing recovery unit, and secondary suction condensing unit cools and recovers residual amine gas.The production device system of the utility model has good amine removal effect, and realizes amine recovery with low energy consumption.

Description

Technical Field

[0001] This utility model belongs to the field of chemical production equipment technology, specifically relating to a production system for removing and reusing amine substances in the sodium sarcosinate production process. Background Technology

[0002] Sodium sarcosinate, an important fine chemical product, is widely used in daily chemicals, pharmaceuticals, and food additives. Its production process mainly involves an amination reaction between sodium chloroacetate and an aqueous solution of methylamine under alkaline conditions. The reaction equation is as follows:

[0003] ClCH2COONa + CH3NH2 → (CH3) NHCH2COONa + NaCl

[0004] In actual production, methylamine is usually required in excess by several times to improve the conversion rate of sodium chloroacetate. After the reaction, in addition to the target product sodium sarcosinate, the system contains a large amount of unreacted methylamine, a small amount of sodium chloride, and impurities such as sodium disarcosinate. The presence of these amines leads to a decrease in product purity, abnormal odor, and adverse effects on subsequent processing, severely restricting the product's market competitiveness.

[0005] Existing amine removal processes mainly employ direct distillation, which has the following drawbacks:

[0006] 1. High energy consumption: Directly heating and distilling the reaction solution requires a large amount of heat energy;

[0007] 2. Incomplete amine removal: Conventional distillation can only remove 85%-90% of amines, leaving a relatively high residual amount;

[0008] 3. Complex operation: It requires frequent adjustment of temperature and pressure parameters, and the control system is complex;

[0009] 4. Low amine recovery rate: Most of the volatile amine gases are directly absorbed and treated, making it difficult to efficiently recover and reuse them;

[0010] Therefore, developing an efficient, energy-saving, easy-to-operate amine removal device that can recover amine substances is of great significance for improving the quality of sodium sarcosinate products and reducing production costs. Utility Model Content

[0011] The purpose of this invention is to overcome the problems of low amine removal efficiency, high energy consumption, and difficulty in recovering amines in the production process of sodium sarcosinate in the prior art, and to provide a production device system with reasonable structure, good amine removal effect, low energy consumption, and the ability to recover amines.

[0012] This utility model relates to a methylamine removal and recycling production system for sodium sarcosinate production, comprising: a raw material pretreatment unit, an amine stripping unit, a primary condensation and recovery unit, and a secondary suction and condensation unit connected in sequence; the raw material pretreatment unit is used to pretreat and heat the sodium sarcosinate reaction solution; the reaction solution after passing through the raw material pretreatment unit enters the amine stripping unit for heating and amine stripping; the gas obtained from amine stripping enters the primary condensation and recovery unit; the primary condensation and recovery unit condenses part of the amine and vapor into liquid and collects it; the secondary suction and condensation unit receives the uncondensed amine gas from the primary condensation and recovery unit and cools and recovers the residual amine gas.

[0013] According to an embodiment of the methylamine removal and recycling production system of the sodium sarcosinate production process of this utility model, the raw material pretreatment unit of the system specifically includes a preheater and a raw material delivery pump. The raw material delivery pump sends the sodium sarcosinate reaction solution into the preheater, and after being heated in the preheater, it is output to the amine stripping unit.

[0014] According to an embodiment of the methylamine removal and recycling production system for sodium sarcosinate production according to this utility model, the amine stripping unit includes a first pump, a second pump, a heater, and an amine stripper. The reaction liquid from the raw material pretreatment unit enters the amine stripper. The circulation outlet of the amine stripper is connected to the first pump, the first pump is connected to the heater, and the heater is connected to the circulation inlet of the amine stripper. The sodium sarcosinate reaction liquid is circulated by the first pump and heated by the heater. The waste heat pipe of the heater is connected to a preheater for waste heat heating. The second pump is connected to another outlet of the amine stripper and is used to transport the amine-removed sodium sarcosinate solution to the next process after the amine residue in the sodium sarcosinate solution in the amine stripping unit is lower than a certain threshold.

[0015] According to an embodiment of the methylamine removal and recycling production system of the sodium sarcosinate production process of this utility model, the amine stripper is filled with stainless steel Pall ring packing.

[0016] According to an embodiment of the methylamine removal and recycling production system of the sodium sarcosinate production process of this utility model, the primary condensation and recovery unit includes: a first storage tank and a first cooler; the first cooler receives the gas obtained from amine distillation and condenses it into liquid; the first storage tank collects the condensed liquid.

[0017] According to an embodiment of the methylamine removal and recycling production system of the sodium sarcosinate production process of this utility model, the primary condensation and recovery unit further includes: a third pump, the outlet of the first storage tank is connected to the third pump, and the third pump pumps the liquid from the first storage tank into the second storage tank.

[0018] According to an embodiment of the methylamine removal and recycling production system for sodium sarcosinate production process of this utility model, the secondary suction and condensation unit includes: an ejector, a second storage tank, a second cooler, a fourth pump, and a fifth pump; the ejector is connected to the first cooler and is used to draw in the gas that has not been condensed by the first cooler and send it into the second storage tank; the fourth pump is connected to the circulating liquid outlet of the second storage tank, pumps the liquid in the second storage tank out, and after the material is cooled by the second cooler, it is provided to the ejector as working fluid; the fifth pump is connected to the outlet of the second storage tank to output the amine water from the second storage tank.

[0019] According to an embodiment of the methylamine removal and recycling production system of the sodium sarcosinate production process of this utility model, a balance pipe is connected between the pipe between the first cooler and the injector and the top of the first storage tank to balance the pressure between the pipes and facilitate the flow of liquid from the first cooler into the first storage tank.

[0020] According to an embodiment of the methylamine removal and recycling production system for sodium sarcosinate production process of this utility model, it further includes: a PLC control system, which is connected to the raw material pretreatment unit, the amine stripping unit, the primary condensation and recovery unit and the secondary suction and condensation unit respectively, so as to control the working process of the raw material pretreatment unit, the amine stripping unit, the primary condensation and recovery unit and the secondary suction and condensation unit.

[0021] According to an embodiment of the methylamine removal and recycling production system of the sodium sarcosinate production process of this utility model, the output port of the fifth pump is connected to the chloroacetic acid and methylamine reaction device in the sodium sarcosinate production process, so as to output the amine water from the second storage tank to the chloroacetic acid and methylamine reaction device.

[0022] This invention achieves an amine removal rate of over 99.5%, significantly improving product purity. Utilizing raw material preheating and waste heat recovery, along with staged cooling and concentration, it greatly reduces cooling consumption, lowering energy consumption by 30%-40% compared to traditional processes. The recovered amine solution achieves a mass concentration of up to 70%, eliminating the generation of low-concentration amine solution. The amine solution concentration meets the requirements for subsequent reactions, reducing raw material consumption. Attached Figure Description

[0023] Figure 1 The diagram shown is a flowchart of the production device system of this utility model.

[0024] Figure 2 The diagram shown is a schematic diagram of an embodiment of the present invention. Detailed Implementation

[0025] To make the objectives, contents, and advantages of this utility model clearer, the specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples.

[0026] Figure 1 The diagram shown is a flowchart of a methylamine removal and recycling production system for sodium sarcosinate production according to this invention. Figure 1 As shown, the system consists of raw material pretreatment unit 1, amine stripping unit 2, primary condensation and recovery unit 3, and secondary suction and condensation unit 4. Figure 1 As shown, the sodium sarcosinate reaction solution is fed into the system's raw material pretreatment unit 1. After pretreatment and heating in the system's raw material pretreatment unit 1, it is sent to the amine distillation unit 2 for heating and amine distillation. The methylamine and other gases obtained from amine distillation are sent to the primary condensation and recovery unit 3, where some of the amine and water vapors are condensed into liquid and collected. The uncondensed amine gas from the primary condensation and recovery unit 3 is sent to the secondary suction and condensation unit 4. The secondary suction and condensation unit 4 cools and recovers the residual amine gas. The cooled and recovered amine water can be output from the secondary suction and condensation unit 4 to the preceding reaction process (the reaction process of chloroacetic acid and methylamine).

[0027] This invention adopts a staged condensation design. The first-stage condensation and recovery unit 3 achieves preliminary condensation of some amine gas, and the second-stage suction and condensation unit 4 performs secondary suction and recovery of uncondensed amine gas. Combined with deep cooling, this ensures zero emission of amine substances.

[0028] Figure 2 The diagram shown is a schematic representation of an embodiment of the present invention. Figure 2 As shown, the raw material pretreatment unit 1 of this embodiment specifically includes a preheater 11. The amine stripping unit 2 includes a first pump 21, a second pump 22, a heater 23, and an amine stripper 24. The primary condensation and recovery unit 3 includes a first storage tank 31, a first cooler 32, and a third pump 33. The secondary suction and condensation unit 4 includes an ejector 41, a second storage tank 42, a second cooler 43, a fourth pump 44, and a fifth pump 45.

[0029] like Figure 2 As shown, the sodium sarcosinate reaction solution is pumped into the preheater 11 at a certain flow rate by a raw material transfer pump. In the preheater 11, it is heated to 40℃-70℃ by waste hot water before entering the amine stripper 24. The amine stripper 24 can be filled with stainless steel Pall ring packing. The bottom of the amine stripper 24 has an outlet connected to a first pump 21, which is connected to a heater 23. The heater 23 is connected to the circulation inlet of the amine stripper 24. The material is circulated through the first pump 21 and heated by the heater 23, preferably to 70-100℃. The waste heat from the heater 23 can be circulated back to the preheater 11 for further heating. The waste heat from the preheater 11 is not limited to that from the heater 23; it can also be supplied by other waste heat from the production system.

[0030] like Figure 2As shown, the first cooler 32 uses circulating cooling water to condense some of the amine and water vapors into liquid, which is then collected in the first storage tank 31. In one embodiment, the operating pressure of the amine vaporizer 24 is controlled at a minimum vacuum of -0.05 MPa (gauge pressure), and the bottom temperature is controlled to be less than 100°C. Under these conditions, amines such as methylamine in the reaction liquid volatilize into gas and enter the first-stage first cooler 32 through the top. The first cooler 32 uses circulating cooling water to condense some of the amine and water vapors into liquid, which is then collected in the first storage tank 31. The outlet of the first storage tank 31 is connected to a third pump 33, which pumps the liquid from the first storage tank 31 into the second storage tank 42.

[0031] like Figure 2 As shown, uncondensed amine gas in the first cooler 32 is drawn into the second storage tank 42 by the suction of the injector 41. Through injection absorption, the amine can be dissolved in the aqueous solution, thus increasing the concentration in the second storage tank 42. A balance pipe connects the pipe between the first cooler 32 and the injector 41 to the top of the first storage tank 31 to balance the pressure between the pipes. This facilitates the flow of liquid from the first cooler 32 into the first storage tank 31. The fourth pump 44 is connected to the circulating liquid outlet of the second storage tank 42. The fourth pump 44 pumps out the liquid from the second storage tank 42 and provides 0.2 MPa of material as working fluid to the injector 41, creating a negative pressure that draws in residual amine gas. The second cooler 43 is connected between the fourth pump 44 and the injector 41. The second cooler 43 uses 10°C chilled water to further cool the material, ensuring a lower temperature of the material entering the injector 41, which is more conducive to the absorption of amine gas, allowing the remaining uncondensed amine gas to be recovered into the second storage tank 42. The high-concentration amine water collected in the second storage tank 42 is pumped by the fifth pump 45 at a certain flow rate to the preceding reaction process (the reaction process of chloroacetic acid and methylamine).

[0032] After the above treatment, the residual amine content in the sodium sarcosinate solution was reduced to below 10 ppm, and the total recovery rate of amine substances reached 99.9%. The amine-free sodium sarcosinate solution was then transported to the next process by the second pump 22 at a certain flow rate.

[0033] The entire system is connected to a PLC control system (not shown) to achieve automated control. All parameters can be displayed and adjusted in real time on the operation panel, and the system operates stably.

[0034] This invention achieves fully automated operation from raw material pretreatment to efficient amine recovery by optimizing and integrating processes such as amine removal, recovery condensation, and concentration. The system integrates existing equipment and is particularly suitable for removing excess methylamine during the reaction of sodium chloroacetate and methylamine to prepare sodium sarcosinate. The integrated system includes a staged condensation design: a primary condensation and recovery unit uses a tubular cooler to achieve initial condensation of some amine gas; a secondary suction condensation unit utilizes the negative pressure generated by a Venturi ejector to re-suction and recover uncondensed amine gas, combined with deep cooling with chilled water to ensure zero emission of amine substances. The device uses a thermal energy cascade utilization technology to preheat the raw materials with the waste heat generated in the amine distillation process, and dynamically adjusts the heating power with an automated temperature control system, reducing unit product energy consumption by 30%-40% compared to existing processes. The recovered amine solution concentration can reach up to 70%, which can be directly reused in the condensation reaction of chloroacetic acid and methylamine, forming a closed-loop production system. The entire process can be operated in a closed loop, eliminating amine leakage problems. The entire operation is fully automated, simple to operate, and has low operating costs.

[0035] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A methylamine removal and recycling production system for sodium sarcosinate production, characterized in that, include: The raw material pretreatment unit, the amine stripping unit, the primary condensation and recovery unit, and the secondary suction and condensation unit are connected in sequence. The raw material pretreatment unit is used for pretreatment and heating of the sodium sarcosinate reaction solution; The reaction liquid from the raw material pretreatment unit enters the amine stripping unit for heating and amine stripping; the gas obtained from amine stripping enters the primary condensation and recovery unit. The primary condensation and recovery unit condenses a portion of the amine and vapor into liquid and collects it. The secondary suction and condensation unit receives the amine gas that has not been condensed by the primary condensation and recovery unit, and cools and recovers the residual amine gas.

2. The methylamine removal and recycling production system for sodium sarcosinate production as described in claim 1, characterized in that, The system's raw material pretreatment unit specifically includes a preheater and a raw material delivery pump. The raw material delivery pump sends the sodium sarcosinate reaction solution into the preheater, where it is heated and then output to the amine distillation unit.

3. The methylamine removal and recycling production system for sodium sarcosinate production as described in claim 2, characterized in that, The amine stripping unit includes a first pump, a second pump, a heater, and an amine stripper; The reaction liquid after passing through the raw material pretreatment unit enters the amine distiller. The circulation outlet of the amine distiller is connected to the first pump, the first pump is connected to the heater, and the heater is connected to the circulation inlet of the amine distiller. The sodium sarcosinate reaction liquid is circulated through the first pump and heated by the heater. The waste heat pipe of the heater is connected to the preheater so that the preheater can use waste heat for heating. The second pump is connected to another outlet of the amine stripper and is used to transport the amine-removed sodium sarcosinate solution to the next process after the residual amine content in the sodium sarcosinate solution in the amine stripper unit is lower than a certain threshold.

4. The methylamine removal and recycling production system for sodium sarcosinate production as described in claim 3, characterized in that, The amine steamer is filled with stainless steel Pall ring packing.

5. The methylamine removal and recycling production system for sodium sarcosinate production as described in claim 1, characterized in that, The primary condensation recovery unit includes: a first storage tank and a first cooler; The first cooler receives the gas obtained from amine distillation and condenses it into a liquid; The first storage tank collects the condensed liquid.

6. The methylamine removal and recycling production system for sodium sarcosinate production as described in claim 5, characterized in that, The primary condensate recovery unit also includes a third pump, the outlet of the first storage tank is connected to the third pump, and the third pump pumps the liquid from the first storage tank into the second storage tank.

7. The methylamine removal and recycling production system for sodium sarcosinate production as described in claim 5, characterized in that, The secondary suction and condensation unit includes: an ejector, a second storage tank, a second cooler, a fourth pump, and a fifth pump; The injector is connected to the first cooler and is used to draw in the gas that has not been condensed by the first cooler and send it into the second storage tank. The fourth pump is connected to the circulating liquid outlet of the second storage tank, pumps out the liquid in the second storage tank, and after the material is cooled by the second cooler, it is supplied to the injector as working fluid. The fifth pump is connected to the outlet of the second storage tank to output the amine water from the second storage tank.

8. The methylamine removal and recycling production system for sodium sarcosinate production as described in claim 7, characterized in that, A balance pipe is connected between the pipe between the first cooler and the injector and the top of the first storage tank to balance the pressure between the pipes, so that the liquid from the first cooler can flow into the first storage tank.

9. The methylamine removal and recycling production system for sodium sarcosinate production as described in claim 1, characterized in that, Also includes: The PLC control system is connected to the raw material pretreatment unit, the amine stripping unit, the primary condensation and recovery unit, and the secondary suction and condensation unit to control the operation of these units.

10. The methylamine removal and recycling production system for sodium sarcosinate production as described in claim 8, characterized in that, The outlet of the fifth pump is connected to the chloroacetic acid and methylamine reaction unit in the sodium sarcosinate production process, so as to output the amine water from the second storage tank to the chloroacetic acid and methylamine reaction unit.

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