Glyphosate continuous hydrolysis dealcoholization tail gas resource recycling grading process

Abstract

The present application relates to a kind of glyphosate continuous hydrolysis dealcoholization tail gas resourceization grading recovery process, acidolysis solution is sequentially subjected to gradient heating N-stage dealcoholization treatment after preheating, 3≤N≤6;Any one or more levels of dealcoholization treatment in the first stage, the second stage, the third stage is generated by gas phase, and methanol, methylal and chloromethane are obtained by rectification recovery;The gas phase generated after dealcoholization treatment in other stages is recovered to obtain water, methanol and chloromethane by rectification.The hydrogen chloride gas generated by hydrolysis enters dimethyl phosphite hydrogen chloride tail gas absorption tower, low-concentration hydrochloric acid generated after two-stage hydrogen chloride tail gas absorption tower, and hydrogen chloride gas is absorbed again as high-concentration hydrochloric acid by hydrogen chloride tail gas absorption tower, and other mixed tail gas generated by acidolysis is separated by gas-liquid separator through gas phase pipeline, and enters gas phase rectification system and chloromethane recovery system to recover methylal, methanol and chloromethane respectively.This method can greatly reduce the consumption level of liquid caustic soda, hydrochloric acid and other single factors and the replacement frequency of condenser, further reducing production cost.

Description

Technical Field

[0001] This invention discloses a graded recovery process and system for the resource utilization of glyphosate continuous hydrolysis deethanolation tail gas, belonging to the field of chemical production technology, specifically involving the recovery process of tail gas in continuous acid hydrolysis of glyphosate. Background Technology

[0002] The main components of the tail gas from the continuous hydrolysis and alcohol desulfurization process of glyphosate synthesis via the alkyl ester method are a mixture of water, methyl acetal, methanol, hydrogen chloride, and chloromethane.

[0003] The synthesis solution refers to a mixed solution obtained by depolymerization, condensation and esterification of raw materials such as methanol (anhydrous methanol), paraformaldehyde (or other formaldehyde sources), glycine (or other raw materials with chloroacetic acid as the starting material), and dimethyl phosphite (or other alkyl phosphates), with the main components being organophosphorus intermediates (glyphosate precursors) such as N-methoxyalkyl ester methylglycine.

[0004] The mainstream recovery route for the hydrolysis tail gas of glyphosate synthesis liquid via alkyl ester method is the gas phase recovery route. That is, the main components of glyphosate hydrolysis tail gas, which is water, methyl acetal, methanol, hydrogen chloride and chloromethane, are neutralized in the gas phase to remove hydrogen chloride gas. The remaining tail gas is a quaternary mixed gaseous system composed of methyl acetal-methanol-water-chloromethane. It is separated by a two-stage distillation column and a condenser. Specifically, water-methanol-methyl acetal-chloromethane are separated from the bottom of the column in order of the boiling point of the components.

[0005] This method involves fewer phase changes and lower energy consumption, but it suffers from poor operational stability: First, compared to the liquid phase route, the material is a mixture of multiple gaseous components, with a larger total material volume and a load 1.5 times that of the liquid phase. Furthermore, the high proportion of chloromethane (accounting for 30% of the total tail gas) leads to instability in the recovery system. Especially in the event of an emergency power outage, a large amount of flammable and explosive gases are released from the emergency pressure relief system, thus posing significant safety and environmental hazards due to poor operational stability. Second, the neutralization of the hydrolysis tail gas requires the addition of liquid alkali to raise the pH value, resulting in significant wear and corrosion of the neutralization tower. Third, the recovered methyl acetal has a high content of chloromethane and other organic impurities, resulting in poor methyl acetal quality and negative user experience in downstream solvent and paint industries, leading to numerous customer complaints. Fourth, the hydrolysis tail gas contains approximately 3% hydrogen chloride, which must be neutralized with liquid alkali before entering the gas phase distillation recovery system. This requires a large amount of liquid alkali, increasing production costs and complicating the later treatment of wastewater from the dehydration tower at the sewage treatment plant. Summary of the Invention

[0006] This invention provides a continuous hydrolysis deethanolation tail gas resource recovery and staged recovery process for glyphosate. It primarily uses methanol as a solvent, paraformaldehyde, glycine, and dimethyl phosphite as initial raw materials, and triethylamine as a catalyst. Heating generates a synthesis liquid, which is then acidified with hydrochloric acid to produce glyphosate acid hydrolysate. This acid hydrolysate undergoes further hydrolysis and acid hydrolysis upon heating, simultaneously releasing the byproducts of hydrolysis and acid hydrolysis, namely methylal and chloromethane, as well as the solvents methanol and water. Based on the mechanisms of hydrolysis and acid hydrolysis and the composition and properties of the tail gas, the tail gas is continuously hydrolyzed and deethanolated, and then fractionally fed into a gas-phase distillation recovery system.

[0007] The glyphosate continuous hydrolysis deethanolation tail gas resource utilization and graded recovery process includes the following steps: (1) After the acid hydrolysate is preheated, it is subjected to N-stage dealcoholization treatment with gradient temperature increase, 3≤N≤6; In some cases, the preheating temperature of the acid hydrolysate is controlled at 40-60℃ before it enters the primary dehydrogenation reactor. A pneumatic regulating valve is used to control the feed flow rate of the preheated acid hydrolysate, maintaining it at 10-15 m³ / h. 3 Within a range of / h, the acid hydrolysate transfer pump is interlocked with the lower liquid level of the acid hydrolysate storage tank and the upper liquid level of the first-stage dehydrogenation reactor. The pump will stop operating when the liquid level in the acid hydrolysate storage tank is low or the liquid level in the first-stage dehydrogenation reactor is high.

[0008] (2) The gas phase generated after any one or more of the first, second and third stages of alcohol removal treatment is recovered by distillation to obtain methanol, methyl acetal and chloromethane; (3) The gas phase generated after other stages of alcohol removal is recovered by distillation to obtain water, methanol and chloromethane.

[0009] The temperature gradient increases from 70°C to 130°C. The temperature gradient can be either constant or non-constant, and the temperature gradient is 5-20°C.

[0010] If N is 3, then the gradient heating process is 70~85℃, 90-100℃, and 120-130℃.

[0011] If N is 4, then the gradient heating process is 70~85℃, 90-95℃, 100-105℃, and 120-130℃.

[0012] If N is 5, then the gradient heating process is 60~75℃, 76-85℃, 86-95℃, 96-100℃, and 101-120℃.

[0013] The flow rate when the product enters the next stage for deethanolation is 180-300 m³ / h.

[0014] In some implementation cases, with attachment Figure 1Taking the 5th level described in the text as an example, the present invention uses the following process to achieve the above separation steps: (1) The acid hydrolysate from the K10000L mixing vessel is transferred by pump to the K40000L acid hydrolysate transfer tank, and then pumped into the acid hydrolysate preheater for initial heating and preheating. The preheating temperature of the acid hydrolysate is controlled at 40-60℃. After preheating, it enters the primary deethanolination vessel. The inlet and outlet of the shell side of the acid hydrolysate preheater are methanol wastewater at 100-120℃, and the flow rate of methanol wastewater is 40-50 m³ / h. 3 / h.

[0015] (2) A pneumatic regulating valve is used to control the feed flow rate of the preheated acid hydrolysate, and the feed flow rate of the acid hydrolysate is controlled at 10-15 m³ / h. 3 Within a range of / h, the acid hydrolysate transfer pump is interlocked with the lower liquid level of the acid hydrolysate storage tank and the upper liquid level of the first-stage dehydrogenation reactor. The pump will stop operating when the liquid level in the acid hydrolysate storage tank is low or the liquid level in the first-stage dehydrogenation reactor is high.

[0016] (3) The acid hydrolysate is transported to the external circulation graphite reboiler of the primary dehydration reactor via the external circulation pump for circulation heating, and then collected to the secondary dehydration reactor. After being heated to 61-75℃ by the external circulation graphite reboiler of the primary dehydration reactor, the pneumatic regulating valve to the secondary dehydration reactor is opened to transfer the solution to the secondary dehydration reactor. The valve opening is adjusted by the collection flow meter to ensure that the liquid level in the reactor is stable. The flow rate of the primary transfer pump is controlled in the range of 180-300 m³ / h, and the flow rate of the collection flow meter is controlled in the range of 10-15 m³ / h. The primary transfer pump is stopped and interlocked with the lower limit of the primary dehydration reactor and the upper limit of the secondary dehydration reactor.

[0017] (4) The acid hydrolysate in the secondary alcoholysis reactor is transported to the external circulation graphite reboiler of the secondary alcoholysis reactor for circulation heating via the external circulation pump of the secondary alcoholysis reactor, and then collected to the tertiary alcoholysis reactor. After being heated to 76-85℃ by the reboiler, the pneumatic valve to the tertiary alcoholysis reactor is opened to transfer the solution to the tertiary alcoholysis reactor. The valve opening is adjusted by the collection flow meter to ensure a stable liquid level in the reactor. The flow rate of the external circulation pump of the secondary alcoholysis reactor is controlled in the range of 180-200 m³ / h, and the flow rate of the collection flow meter is controlled in the range of 8-13 m³ / h. The stop of the external circulation pump of the secondary alcoholysis reactor is interlocked with the lower limit of the secondary alcoholysis reactor and the upper limit of the tertiary alcoholysis reactor.

[0018] (5) The tail gas from the primary and secondary alcohol removal reactors is finally collected in the gas-liquid separator through their respective gas phase pipelines. The gas phase then enters the gas phase distillation system and is separated by the methanol tower to obtain methanol, methyl acetal and chloromethane.

[0019] (6) The acid hydrolysate in the tertiary dehydrogenation reactor is transported to the external circulation graphite reboiler of the tertiary dehydrogenation reactor for circulation heating via a tertiary transfer pump, and then collected to the tertiary dehydrogenation reactor. After being heated to 86-95℃ by the external circulation graphite reboiler of the tertiary dehydrogenation reactor, the pneumatic regulating valve to the tertiary dehydrogenation reactor is opened to transfer the solution to the tertiary dehydrogenation reactor. The flow rate of the tertiary transfer pump is controlled within the range of 180-200 m³ / h, and the flow rate of the collection flow meter is controlled within the range of 6-11 m³ / h. The tertiary transfer pump is stopped and interlocked with the lower limit of the tertiary dehydrogenation reactor and the upper limit of the tertiary dehydrogenation reactor.

[0020] (7) The acid hydrolysate in the fourth-stage dehydration reactor is transported to the external circulation graphite reboiler of the fourth-stage dehydration reactor for circulation heating via a fourth-stage transfer pump, and then collected to the fifth-stage dehydration reactor. After being heated to 95-100℃ by the external circulation graphite reboiler of the fourth-stage dehydration reactor, the pneumatic regulating valve to the fifth-stage dehydration reactor is opened to transfer the solution to the fifth-stage dehydration reactor. The flow rate of the fourth-stage transfer pump is controlled in the range of 180-200 m³ / h, and the flow rate of the collection flow meter is controlled in the range of 4-9 m³ / h. The stop of the fourth-stage transfer pump is interlocked with the lower limit of the fourth-stage dehydration reactor and the upper limit of the fifth-stage dehydration reactor.

[0021] (8) The tail gas from the three-stage and four-stage dehydrogenation reactors is finally collected in the gas-liquid separator through their respective matching gas phase pipelines. The gas phase then enters the dehydration tower of the gas phase distillation system to distill and separate methanol, methyl acetal, chloromethane and water.

[0022] (9) The acid hydrolysate in the fifth-stage dealcoholization reactor is transported to the external circulation graphite reboiler of the fifth-stage dealcoholization reactor for circulating heating via a fourth-stage transfer pump. The temperature is first raised through the external circulation graphite reboiler of the fifth-stage dealcoholization reactor. The flow rate of the external circulation pump is controlled within the range of 180-200 m³ / h, and the temperature inside the fifth-stage dealcoholization reactor is controlled within 101-120℃. After the liquid level in the fifth-stage dealcoholization reactor reaches the upper limit, the pneumatic valve from the fifth-stage dealcoholization reactor to the crystallization reactor is opened to transfer the solution to the crystallization reactor. The feed inlet of the crystallization reactor is controlled by a pneumatic valve, with a flow rate controlled at 30-50 m³ / h and a feed rate set at 3-6 m³ / reactor. After feeding a single reactor, the feed valve of that dealcoholization reactor is automatically closed. Then, after the liquid level in the dealcoholization reactor reaches the upper limit, the feed valve of the next dealcoholization reactor is opened via the central control system.

[0023] (10) The gas phase pipeline of the fifth-stage alcohol removal reactor is connected to the inlet of the first-stage hydrogen chloride tail gas absorption tower, and the hydrogen chloride tail gas from the alcohol removal reactor... The hydrogen chloride tail gas is absorbed by a primary hydrogen chloride tail gas absorption tower and a secondary hydrogen chloride tail gas absorption tower, respectively. The absorbent liquid in the secondary absorption tower is pumped and controlled by a regulating valve. Part of it is returned to the top of the tower to continue absorbing hydrogen chloride tail gas, and part of it is pumped to the top of the primary absorption tower to absorb hydrogen chloride tail gas. The hydrochloric acid concentration in the primary hydrogen chloride tail gas absorption tower is detected online. Once it reaches 31%, it is pumped into the glyphosate acid hydrolysis process by the absorbent liquid feeding pump.

[0024] To achieve the objectives of this invention, the following data were obtained by detecting and analyzing the gas phase components at different dealcoholization temperatures: 0-75℃, methyl acetal 35-50%, methanol 10-20%, chloromethane 18-30%.

[0025] 75-80℃, 28-45% methyl acetal, 19-30% methanol, 20-25% chloromethane.

[0026] 81-85℃, 20-25% methyl acetal, 40-55% methanol, 18-25% chloromethane.

[0027] 86-90℃, 10-15% methyl acetal, 25-50% methanol, 10-25% chloromethane, 8-10% water.

[0028] 91-95℃, methyl acetal 3.5-5%, methanol 35-45%, chloromethane 25-35%, water 10-15%.

[0029] 96-100℃, 0.3-0.5% methyl acetal, 20-30% methanol, 20-30% chloromethane, 18-29.5% water.

[0030] 101-105℃, trace amounts of methyl acetal, 1-5% methanol, 12-20% chloromethane, 72-73% water, and 2-3% hydrogen chloride.

[0031] Based on the existing methods described above, which exhibit different separation effects at different temperatures, this application adjusts the process conditions accordingly. Achieving efficient separation makes it easier to classify and recover useful components from exhaust gases.

[0032] 1. Compared with the original de-alcohol tail gas recovery system, the process and system developed in this invention realize the resource recovery and separation of de-alcohol tail gas. According to the material composition of de-alcohol tail gas at different temperature ranges, it selectively enters the material inlet of different columns of the original gas phase distillation system, effectively reducing the energy consumption of the tail gas recovery stage and saving 10% of steam consumption.

[0033] 2. The high-temperature section of the de-alcoholization tail gas contains a small amount of hydrogen chloride. The original treatment process involves alkali neutralization followed by gas-phase distillation to recover methanol, methyl acetal, and chloromethane. The process and system developed in this invention do not require an alkali neutralization step, reducing liquid alkali consumption by 140 kg per batch. It also avoids the need for subsequent recovery and treatment of sodium chloride in the wastewater. The 31% hydrochloric acid formed by absorption through the two-stage hydrogen chloride tail gas absorption tower can be used for glyphosate acid hydrolysis, effectively reducing hydrochloric acid consumption. 401 kg of 31% hydrochloric acid can be recovered per batch, allowing for repeated reuse and significant economic benefits.

[0034] 3. Compared with the traditional batch reactor process, this new process is a continuous process, with a large capacity per unit volume of reactor and more significant economies of scale.

[0035] 4. Compared with traditional processes, this process does not have the problem of acidic solution corroding the gas phase distillation system. The requirements for equipment materials can be reduced, which reduces fixed asset investment and thus reduces the fixed asset depreciation cost of glyphosate, thereby improving the market competitiveness of the product. Attached Figure Description

[0036] Figure 1 A flow chart of a graded recovery process for the continuous hydrolysis deethanolation tail gas of glyphosate. The system includes: 1. Acid hydrolysis liquid transfer tank; 2. Acid hydrolysis liquid transfer pump; 3. Acid hydrolysis preheater; 4. First-stage dehydrogenation kettle; 5. First-stage dehydrogenation kettle external circulation pump; 6. First-stage dehydrogenation kettle external circulation graphite reboiler; 7. Second-stage dehydrogenation kettle; 8. Second-stage dehydrogenation kettle external circulation graphite reboiler; 9. Second-stage dehydrogenation kettle external circulation pump; 10. Third-stage dehydrogenation kettle; 11. Third-stage dehydrogenation kettle external circulation graphite reboiler; 12. Third-stage dehydrogenation kettle external circulation pump; 13. Fourth-stage dehydrogenation kettle; 14. Fourth-stage dehydrogenation kettle external circulation graphite reboiler; 15. Fifth-stage dehydrogenation kettle; 16. Fifth-stage dehydrogenation kettle external circulation graphite reboiler; 17. Fifth-stage dehydrogenation kettle external circulation pump; 18. First-stage hydrogen chloride tail gas absorption tower; 19. Second-stage hydrogen chloride tail gas absorption tower; 20. Absorbent liquid feed pump; 21. Absorbent liquid feed pump; 22. Gas-liquid separator; 23. Detailed Implementation

[0037] The embodiments of the present invention are used to further illustrate the substantive content of the invention, but are not intended to limit the invention: Example 1 A glyphosate continuous hydrolysis deethanolation tail gas resource utilization and graded recovery system, wherein the acid hydrolysis liquid transfer and storage tank 1 is connected to the acid hydrolysis preheater 3 via the acid hydrolysis liquid transfer pump 2, and the acid hydrolysis preheater 3 is connected to the acid hydrolysis liquid inlet of the primary deethanolation reactor 4 via a pipeline. The bottom valve of the primary dehydrogenation vessel 4 is connected to the primary dehydrogenation vessel external circulation pump 5, which is connected to the primary dehydrogenation vessel external circulation graphite reboiler 6 and the secondary dehydrogenation vessel 7, respectively. The bottom valve of the secondary dehydrogenation vessel 7 is connected to the external circulation graphite reboiler 8 of the secondary dehydrogenation vessel and the tertiary dehydrogenation vessel 10 via the external circulation pump 9 of the secondary dehydrogenation vessel; The bottom valve of the tertiary dehydrogenation vessel 10 is connected to the external circulation graphite reboiler 11 of the tertiary dehydrogenation vessel and the tertiary dehydrogenation vessel 13 via the external circulation pump 12 of the tertiary dehydrogenation vessel. The bottom valve of the fourth-stage alcohol removal vessel 13 is connected to the fourth-stage alcohol removal vessel external circulation pump 15, which is connected to the fourth-stage alcohol removal vessel external circulation graphite reboiler 14 and the fifth-stage alcohol removal vessel 16 respectively. The bottom valve of the fifth-stage dehydrogenation vessel 16 is connected to the external circulation graphite reboiler 17 and the top of the fifth-stage dehydrogenation vessel 16 via the external circulation pump 18.

[0038] The outlet of the 6-tube side of the external circulation graphite reboiler of the primary dehydrogenation reactor is connected to the inlet of the 4-circulation material of the primary dehydrogenation reactor via a pipeline. The outlet of the external circulation graphite reboiler 8 of the secondary dehydrogenation reactor is connected to the inlet of the circulating material inlet 7 of the secondary dehydrogenation reactor via a pipeline. The tube side outlet of the external circulation graphite reboiler 11 of the tertiary dehydrogenation reactor is connected to the circulating material inlet of the tertiary dehydrogenation reactor 10 via a pipeline. The outlet of the external circulation graphite reboiler 14 of the fourth-stage dehydrogenation reactor is connected to the inlet of the circulating material of the fourth-stage dehydrogenation reactor 13 via a pipeline. The outlet of the external circulation pump 18 of the five-stage dehydrogenation reactor is connected to the inlet of the crystallization reactor via a regulating valve.

[0039] The gas phase outlets of the first-stage dealcoholization vessel 4, the second-stage dealcoholization vessel 7, the third-stage dealcoholization vessel 10, the first-stage dealcoholization vessel external circulation graphite reboiler 6, the second-stage dealcoholization vessel external circulation graphite reboiler 8, and the third-stage dealcoholization vessel external circulation graphite reboiler 11 are combined and connected to the gas phase inlet of the gas-liquid separator 23. The gas phase outlet of the gas-liquid separator 23 is connected to the gas phase inlet of the methanol tower of the gas phase distillation system. The gas phase outlets of the fourth-stage dealcoholization vessel 13 and the fourth-stage dealcoholization vessel external circulation graphite reboiler 14 are combined and connected to the gas phase inlet of the dehydration tower of the gas phase distillation system.

[0040] The top of the fifth-stage dehydrogenation reactor 16 and the gas phase outlet of the external circulation graphite reboiler 17 of the fifth-stage dehydrogenation reactor are connected to the inlet of the first-stage hydrogen chloride tail gas absorption tower 19, and the outlet of the first-stage hydrogen chloride tail gas absorption tower 19 is connected to the inlet of the second-stage hydrogen chloride tail gas absorption tower 20. After the bottom absorbent outlet pipeline of the primary hydrogen chloride tail gas absorption tower 19 is connected to the absorbent feed pump 21, it enters the dimethyl phosphite hydrochloric acid tail gas absorption system through the pipeline.

[0041] The bottom absorbent outlet pipeline of the secondary hydrogen chloride tail gas absorption tower 20 is connected to the absorbent feed pump 22, and is connected via pipeline to the absorbent return pipelines of the primary hydrogen chloride tail gas absorption tower 19 and the secondary hydrogen chloride tail gas absorption tower 20 respectively. The top gas phase outlet of the secondary hydrogen chloride tail gas absorption tower 20 is connected via pipeline to the chloromethane recovery device.

[0042] The shell-side inlets of the primary-stage dehydrogenation reactor external circulation graphite reboiler 6, the secondary-stage dehydrogenation reactor external circulation graphite reboiler 8, the tertiary-stage dehydrogenation reactor external circulation graphite reboiler 11, the quaternary-stage dehydrogenation reactor external circulation graphite reboiler 14, and the quinary-stage dehydrogenation reactor external circulation graphite reboiler 17 are connected to steam pipelines; the shell-side outlets of the primary-stage dehydrogenation reactor external circulation graphite reboiler 6, the secondary-stage dehydrogenation reactor external circulation graphite reboiler 8, the tertiary-stage dehydrogenation reactor external circulation graphite reboiler 11, the quaternary-stage dehydrogenation reactor external circulation graphite reboiler 14, and the quinary-stage dehydrogenation reactor external circulation graphite reboiler 17 are connected to steam condensate pipelines.

[0043] The gas phase outlet of the fourth-stage dehydrogenation vessel 13 and the external circulation graphite reboiler 14 of the fourth-stage dehydrogenation vessel are connected to the gas phase inlet pipe of the gas phase distillation system.

[0044] The gas phase outlet of the 16 external circulation graphite reboiler in the fifth-stage dehydrogenation reactor is connected to the gas phase inlet of the first-stage hydrogen chloride tail gas absorption tower via a pipeline.

[0045] Example 2 (75℃, 85℃, 95℃, 105℃, 120℃) The acid hydrolysate is stored in an acid hydrolysate transfer tank. The acid hydrolysate in the transfer tank is then pumped into an acid hydrolysate preheater for initial heating and preheating to 60°C. It then enters the primary alcohol removal reactor. The feed flow rate of the acid hydrolysate is controlled at 20 m³ / s. 3 The acid hydrolysate is fed into the primary alcohol removal reactor via a feed pump and heated by an external graphite heat exchanger, maintaining the primary reactor temperature at 75°C. The acid hydrolysate is then fed into the second alcohol removal cycle system via the primary reactor feed pump and a pneumatic regulating valve; this process continues sequentially, with the acid hydrolysate entering the secondary, tertiary, and quaternary alcohol removal reactors, where temperatures are controlled at 85°C, 95°C, and 105°C, respectively. The flow rates of the external circulation pumps for the secondary, tertiary, and quaternary alcohol removal reactors are controlled at 300 m³ / h. The acid hydrolysate from the quaternary alcohol removal reactor, after alcohol removal, is fed into the quaternary alcohol removal reactor via the quaternary alcohol removal reactor external circulation pump and a pneumatic regulating valve, maintaining the final reaction temperature at 120°C; the flow rate of the quaternary alcohol removal reactor external circulation pump is also controlled at 300 m³ / h. The gaseous phases escaping from the primary, secondary, and tertiary alcohol removal reactors enter a gas-phase distillation recovery unit, where methanol, methylal, and chloromethane are separated sequentially. The gaseous phases escaping from the quaternary solvent removal reactor enter a gas-phase distillation methanol recovery unit, where water, methanol, and chloromethane are separated sequentially. The tail gas from the quinary alcohol removal reactor, after absorbing hydrogen chloride gas in the primary and secondary water washing towers, is then sent to the chloromethane recovery system by a blower. The flow rate of the absorbent pump in the primary hydrogen chloride tail gas absorption tower is controlled at 5 m³ / s. 3 / h, the flow rate of the absorbent feed pump in the secondary hydrogen chloride tail gas absorption tower is controlled at 3m³ / h. 3 / h.

[0046] The recovered hydrochloric acid concentration is 30.3%, and 380 kg of 30.3% hydrochloric acid can be recovered. The recovered hydrochloric acid is returned to the dimethyl ester workshop as an esterification tail gas absorbent, reducing steam consumption in the tail gas recovery stage by 8.7% and reducing liquid alkali consumption by 120 kg.

[0047] Example 3 (75℃, 100℃, 120℃) The acid hydrolysate is stored in an acid hydrolysate transfer tank. The acid hydrolysate in the transfer tank is then pumped into an acid hydrolysate preheater for initial heating and preheating to 60°C. It then enters the primary alcohol removal reactor. The feed flow rate of the acid hydrolysate is controlled at 20 m³ / s.3 The acid hydrolysate is fed into the primary alcohol removal reactor via a feed pump and heated by an external graphite heat exchanger. The temperature of the primary alcohol removal reactor is controlled at 85℃. The acid hydrolysate is then fed into the second alcohol removal circulating reaction system via the primary alcohol removal reactor feed pump and a pneumatic regulating valve. This process is repeated sequentially, with the acid hydrolysate entering the secondary and tertiary alcohol removal reactors, respectively. The temperatures of each reactor are controlled at 100℃ and 120℃, respectively. The flow rates of the external circulation pumps for the secondary and tertiary alcohol removal reactors are controlled at 300 m³ / h. The escaping gas from the primary and secondary alcohol removal reactors enters a gas-phase distillation recovery unit, where methanol, methylal, and chloromethane are separated sequentially. The escaping gas from the secondary solvent removal reactor enters a gas-phase distillation methanol recovery unit, where water, methanol, and chloromethane are separated sequentially. The tail gas from the tertiary alcohol removal reactor is then sent to the chloromethane recovery system via a blower after absorbing hydrogen chloride gas in the primary and secondary water washing towers. The flow rate of the absorbent pump in the primary hydrogen chloride tail gas absorption tower is controlled at 5 m³ / s. 3 / h, the flow rate of the absorbent feed pump in the secondary hydrogen chloride tail gas absorption tower is controlled at 3m³ / h. 3 / h.

[0048] The recovered hydrochloric acid concentration is 30.8%, and 398 kg of 30.8% hydrochloric acid can be recovered. The recovered hydrochloric acid is returned to the dimethyl ester workshop as an esterification tail gas absorbent, reducing steam consumption in the tail gas recovery stage by 5.2% and reducing liquid alkali consumption by 135 kg.

[0049] Example 4 (85℃, 95℃, 100℃, 120℃) The acid hydrolysate is stored in an acid hydrolysate transfer tank. The acid hydrolysate in the transfer tank is then pumped into an acid hydrolysate preheater for initial heating and preheating to 60°C. It then enters the primary alcohol removal reactor. The feed flow rate of the acid hydrolysate is controlled at 20 m³ / s. 3The acid hydrolysate is heated by an external graphite heat exchanger in the primary alcohol removal reactor via a feed pump, maintaining the reactor temperature at 85°C. The acid hydrolysate then enters the second alcohol removal circulating reaction system via the feed pump and pneumatic regulating valve; this process continues sequentially, with the acid hydrolysate entering the secondary and tertiary alcohol removal reactors, where temperatures are controlled at 95°C and 100°C respectively. The external circulation pumps for the secondary and tertiary alcohol removal reactors are maintained at 300 m³ / h. The acid hydrolysate from the tertiary alcohol removal reactor, after alcohol removal, enters the crystallization reactor via the external circulation pump and pneumatic regulating valve, maintaining the final reaction temperature at 120°C; the external circulation pump flow rate for the tertiary alcohol removal reactor is also maintained at 300 m³ / h. The gaseous phase escaping from the primary and secondary alcohol removal reactors enters the methanol tower inlet of the gas-phase distillation recovery unit, where methanol, methylal, and chloromethane are separated sequentially. The gaseous phase escaping from the tertiary solvent removal reactor enters the dehydration tower of the gas-phase distillation recovery unit, where water, methanol, and chloromethane are separated sequentially. The tail gas from the quaternary alcohol removal reactor, after absorbing hydrogen chloride gas in the primary and secondary water washing towers, is sent to the chloromethane recovery system by a blower. The flow rate of the absorbent pump in the primary hydrogen chloride tail gas absorption tower is controlled at 5 m³ / s. 3 / h, the flow rate of the absorbent feed pump in the secondary hydrogen chloride tail gas absorption tower is controlled at 3m³ / h. 3 / h.

[0050] The recovered hydrochloric acid concentration is 31.5%, and 396 kg of 31.3% hydrochloric acid can be recovered. The recovered hydrochloric acid is returned to the dimethyl ester workshop as an esterification tail gas absorbent, reducing steam consumption in the tail gas recovery stage by 10.6% and reducing liquid alkali consumption by 140 kg.

Claims

1. A continuous hydrolysis deethanolification tail gas resource recovery and staged recycling process for glyphosate, characterized in that, Includes the following steps: The acid hydrolysate is stored in an acid hydrolysate transfer tank. The acid hydrolysate in the transfer tank is then pumped into an acid hydrolysate preheater for initial heating and preheating to 60°C. It then enters the primary dehydrogenation reactor. The feed flow rate of the acid hydrolysate is controlled at 20 m³ / s. 3 / h, the acid hydrolysate is fed into the first-stage dehydrogenation reactor via a feed pump and heated by an external graphite heat exchanger. The temperature of the first-stage dehydrogenation reactor is controlled at 85℃. The acid hydrolysate is then fed into the second dehydrogenation circulation reaction system via the feed pump and a pneumatic regulating valve. This process is repeated sequentially, with the acid hydrolysate entering the second-stage and third-stage dehydrogenation reactors, where the temperatures are controlled at 95℃ and 100℃, respectively. The flow rates of the external circulation pumps for the secondary and tertiary alcohol removal reactors are controlled at 300 m³ / s. 3 / h; The acid hydrolysate from the fourth-stage dealcoholization reactor is controlled to enter the crystallization reactor via an external circulation pump and a pneumatic regulating valve, maintaining the final reaction temperature at 120℃; the flow rate of the external circulation pump is controlled at 300 m³ / s. 3 / h; The gas phase escaping from the primary and secondary alcohol removal reactors enters the methanol tower material inlet of the gas phase distillation and recovery unit, where methanol, methyl acetal, and chloromethane are separated in sequence. The gas phase escaping from the three-stage alcohol removal reactor enters the dehydration tower in the gas phase distillation recovery unit, where water, methanol, and chloromethane are separated in sequence. The tail gas from the fourth-stage alcohol removal reactor is sent to the chloromethane recovery system after absorbing hydrogen chloride gas through the first-stage and second-stage water washing towers and then being blowered. The flow rate of the feed pump for the absorbent liquid in the primary hydrogen chloride tail gas absorption tower is controlled at 5m³ / h. 3 / h, the flow rate of the absorbent feed pump in the secondary hydrogen chloride tail gas absorption tower is controlled at 3m³ / h. 3 / h; The acid hydrolysate is prepared by using methanol as a solvent, paraformaldehyde, glycine, and dimethyl phosphite as initial raw materials, and triethylamine as a catalyst. The synthesis liquid is generated by heating, and the synthesis liquid is then acidified with hydrochloric acid to produce the acid hydrolysate.

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