CN111269089A - Method and system for recovering hydrolysis tail gas of glyphosate synthetic liquid - Google Patents
Method and system for recovering hydrolysis tail gas of glyphosate synthetic liquid Download PDFInfo
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Abstract
The invention relates to the technical field of glyphosate production, in particular to a method and a system for recovering tail gas generated by hydrolysis of glyphosate synthetic liquid. The continuous synthesis method comprises the following steps: carrying out primary hydrolysis reaction and secondary hydrolysis reaction on the acidified glyphosate synthetic solution, and condensing gas after the secondary hydrolysis reaction to obtain condensate and non-condensable gas; mixing gas, non-condensable gas and alkali liquor generated by the primary hydrolysis reaction, carrying out neutralization reaction, mixing the solution obtained after the neutralization reaction with the condensate, carrying out primary rectification on the mixed solution and the gas obtained by the neutralization reaction, and carrying out secondary rectification on the obtained tower bottom liquid to obtain methanol; and performing third rectification on the tower top low-boiling-point substance obtained by the first rectification to obtain the methyl chloride. The method for recovering the hydrolysis tail gas of the glyphosate synthetic liquid has simple process, can effectively recover byproducts and has lower cost.
Description
Technical Field
The invention relates to the technical field of glyphosate production, in particular to a method and a system for recovering tail gas generated by hydrolysis of glyphosate synthetic liquid.
Background
Glyphosate is a highly effective, low toxicity, broad spectrum, biocidal, non-selective herbicide with excellent biological properties. At present, the domestic main stream production process of glyphosate has two routes: alkyl ester process (glycine process) and iminodiacetic acid process (IDA process). The foreign production process is mainly the iminodiacetic acid method of Monsanto in America. The glyphosate in China is mainly produced by an alkyl ester method taking glycine and dimethyl phosphite as main raw materials, the method takes methanol as a reaction solvent, the glycine firstly reacts with polyformaldehyde in the presence of a catalyst triethylamine to form N, N-dimethylolglycine, then the N, N-dimethylolglycine reacts with dimethyl phosphite, and hydrochloric acid is added to hydrolyze the N, N-dimethylolglycine to generate the glyphosate and byproducts methylal and methyl chloride. The main components of the tail gas generated by hydrolyzing the glyphosate synthetic liquid by the glycine method are a mixture of water, methylal, methanol, hydrogen chloride and chloromethane, and the recovery process of the tail gas is referred to as solvent recovery in the glyphosate industry. The synthetic solution is a mixed solution of an organophosphorus intermediate (glyphosate precursor) such as N-methoxyalkyl ester methylglycine as a main component, which is obtained by depolymerizing, condensing and esterifying raw materials such as methanol, paraformaldehyde (or other formaldehyde sources), glycine (or other raw materials starting from chloroacetic acid), dimethyl phosphite (or other alkyl phosphates).
The existing glyphosate hydrolysis process is intermittent hydrolysis, after a synthetic solution and hydrochloric acid in a certain proportion are mixed in a hydrolysis kettle, steam is introduced to raise the temperature to the reaction end point, the hydrolysis reaction is carried out along with the raising of the hydrolysis temperature, the steam of methylal, methanol, chloromethane, water, hydrogen chloride and the like is evaporated out from the reaction kettle, three-stage condensation is carried out, the non-condensable gas of crude chloromethane (containing air and acidity) is treated by a chloromethane recovery device, and a condensate (diluted methanol) is treated by a solvent recovery device.
Patent CN103739625B discloses a continuous hydrolysis process for preparing glyphosate by a glycine method, which comprises the steps of separating gas from liquid of mixed acid, respectively feeding the liquid and the condensed gas into a methylal tower to recover methylal, feeding kettle bottom liquid recovered from the methylal into a methanol recovery tower to recover methanol, and feeding kettle bottom liquid discharged from the methanol recovery tower into a hydrolysis kettle to complete hydrolysis reaction. The method has the advantages of low recovery rate of methylal and high energy consumption.
The traditional recovery process is to condense hydrolysis steam, wherein methanol, methylal, water and a small amount of hydrogen chloride gas with relatively high boiling points are condensed into a liquid phase, which is called dilute methanol; the chloromethane is in gas phase, and is purified by water washing, alkali washing and sulfuric acid drying to obtain chloromethane gas, and the chloromethane product is obtained by compression and condensation. Adding alkali into the condensed dilute methanol for neutralization, respectively recovering methanol and methylal in the dilute methanol by two rectifying towers, recycling the methanol as a solvent to a glyphosate synthesis link, and taking the methylal as a byproduct.
Patent CN108380029A discloses a system and a process for recovering glyphosate solvent by alkyl ester method, the tail gas of glyphosate hydrolysis is sent to a condenser for condensation and separation after neutralization, pressure control and temperature control, the condensate is sent to a diluted methanol solution recovery tank, and the non-condensable gas is sent to a methyl chloride recovery device.
The two processes of hydrolysis and solvent recovery in the glyphosate production process are main processes of steam consumption, a large amount of materials such as methanol, methylal, water and the like are condensed into liquid state, and then enter the tower again to consume a large amount of steam for heating into a steam state, so that the heat of the hydrolyzed steam is wasted, a large amount of generated steam is additionally consumed, and great heat waste is caused.
Disclosure of Invention
In view of this, the technical problem to be solved by the present invention is to provide a method and a system for recovering tail gas from hydrolysis of glyphosate synthetic fluid, and the method for recovering tail gas from hydrolysis of glyphosate synthetic fluid provided by the present invention can effectively recover byproducts and has low cost.
The invention provides a method for recovering tail gas generated by hydrolyzing glyphosate synthetic liquid, which comprises the following steps:
A) carrying out primary hydrolysis reaction on the acidified glyphosate synthetic solution at 90-112 ℃ and-5-20 KPa;
B) performing secondary hydrolysis reaction on the product solution of the primary hydrolysis reaction at 115-130 ℃ and-10 KPa, and condensing the gas after the secondary hydrolysis reaction to obtain a condensate and a non-condensable gas;
mixing the gas generated by the primary hydrolysis reaction, the non-condensable gas and alkali liquor, and performing neutralization reaction;
C) mixing the solution after the neutralization reaction with the condensate, performing first rectification on the mixed solution and the gas obtained by the neutralization reaction at-10 to 10KPa and the tower kettle temperature of 70 to 100 ℃, and performing second rectification on the tower kettle liquid obtained by the first rectification at 0 to 0.8MPa and the tower kettle temperature of 90 to 170 ℃ to obtain methanol; and performing third rectification on the tower top low-boiling-point substances obtained by the first rectification at the temperature of 0-80 KPa, the tower kettle temperature of 45-70 ℃ and the tower top temperature of-10-20 ℃ to obtain methyl chloride and methylal.
Preferably, in the step a), the glyphosate synthetic solution is prepared according to the following method:
a1) carrying out depolymerization reaction on methanol, triethylamine and paraformaldehyde at 40-55 ℃;
a2) performing addition reaction on the product after the depolymerization reaction and glycine at the temperature of 40-55 ℃;
a3) and carrying out condensation reaction on the product after the addition reaction and dialkyl phosphite at the temperature of 40-55 ℃ to obtain synthetic liquid.
Preferably, in the step A), the acidification temperature is 35-55 ℃, and the acidification pressure is-10 KPa.
Preferably, in the step B), the condensation is vacuum cooling, and the pressure of the vacuum cooling is more than or equal to-70 KPa; or the condensation is water adding and cooling, and the temperature after water adding and cooling is 30-90 ℃.
Preferably, in the step B), the temperature of the neutralization reaction is 70-90 ℃, and the pressure is-5-10 KPa.
Preferably, in the step C), the reflux ratio of the first rectification is 1-4: 1; the reflux ratio of the second rectification is 0-4: 1; the reflux ratio of the third rectification is 1-3.5: 1.
preferably, in step C), the second rectification comprises low-pressure methanol rectification and high-pressure methanol rectification;
the pressure of the low-pressure methanol rectification is 0.1-0.3 MPa, the temperature of a tower kettle is 85-120 ℃, and the reflux ratio is 1-4: 1;
the pressure of the high-pressure methanol rectification is 0.4-0.8 MPa, the temperature of a tower kettle is 135-170 ℃, and the reflux ratio is 1-4: 1.
the invention also provides a system for recovering the tail gas generated by hydrolyzing the glyphosate synthetic liquid, which comprises the following components:
a first-stage hydrolysis reaction device;
the second-stage hydrolysis reaction device is connected with a product solution outlet of the first-stage hydrolysis reaction device;
the hydrolysis tail gas condenser is connected with a gas outlet of the secondary hydrolysis reaction device;
the first gas inlet is connected with the gas outlet of the hydrolysis tail gas condenser; a second gas inlet of the alkaline tower is connected with a gas outlet of the primary hydrolysis reaction device;
the first liquid inlet is connected with the liquid outlet of the alkaline tower; a second liquid inlet of the mixing device is connected with a liquid outlet of the hydrolysis tail gas condenser;
the gas inlet is connected with the gas outlet of the alkaline tower; the liquid inlet of the separation tower is connected with the liquid outlet of the mixing device;
a methanol column connected to the liquid outlet of the separation column;
and the methane-removing tower is connected with the gas outlet of the separation tower.
Preferably, the first-stage hydrolysis reaction device comprises a first-stage hydrolysis reaction tower and a first-stage hydrolysis reaction kettle;
the product solution outlet of the first-stage hydrolysis reaction tower is connected with the product solution inlet of the first-stage hydrolysis reaction kettle;
the gas outlet of the primary hydrolysis reaction kettle is connected with the gas inlet of the primary hydrolysis reaction tower;
the second-stage hydrolysis reaction device is a second-stage hydrolysis reaction kettle;
the product solution inlet of the second-stage hydrolysis reaction kettle is connected with the product solution outlet of the first-stage hydrolysis reaction kettle;
and a gas inlet of the hydrolysis tail gas condenser is connected with a gas outlet of the secondary hydrolysis reaction kettle.
Preferably, the methanol tower comprises a low pressure methanol tower and a high pressure methanol tower;
the liquid inlet of the low-pressure methanol tower is connected with the liquid outlet of the separation tower;
and the liquid inlet of the high-pressure methanol tower is connected with the liquid outlet of the low-pressure methanol tower.
The invention provides a method for recovering tail gas generated by hydrolyzing glyphosate synthetic liquid, which comprises the following steps: A) carrying out primary hydrolysis reaction on the acidified glyphosate synthetic solution at 90-112 ℃ and-5-20 KPa; B) performing secondary hydrolysis reaction on the product solution of the primary hydrolysis reaction at 115-130 ℃ and-10 KPa, and condensing the gas after the secondary hydrolysis reaction to obtain a condensate and a non-condensable gas; mixing the gas generated by the primary hydrolysis reaction, the non-condensable gas and alkali liquor, and performing neutralization reaction; C) mixing the solution after the neutralization reaction with the condensate, performing first rectification on the mixed solution and the gas obtained by the neutralization reaction at-10 to 10KPa and the tower kettle temperature of 70 to 100 ℃, and performing second rectification on the tower kettle liquid obtained by the first rectification at 0 to 0.8MPa and the tower kettle temperature of 90 to 170 ℃ to obtain methanol; and performing third rectification on the tower top low-boiling-point substances obtained by the first rectification at the temperature of 0-80 KPa, the tower kettle temperature of 45-70 ℃ and the tower top temperature of-10-20 ℃ to obtain the methyl chloride. The method for recovering the hydrolysis tail gas of the glyphosate synthetic liquid has simple process, can effectively recover byproducts and has lower cost.
Drawings
FIG. 1 is a schematic flow diagram of a system for recovering tail gas from the hydrolysis of glyphosate synthesis solution according to an embodiment of the present invention;
FIG. 2 is a schematic flow chart of a system for recovering tail gas from the hydrolysis of glyphosate synthesis solution according to another embodiment of the present invention.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention provides a method for recovering tail gas generated by hydrolyzing glyphosate synthetic liquid, which comprises the following steps:
A) carrying out primary hydrolysis reaction on the acidified glyphosate synthetic solution at 90-112 ℃ and-5-20 KPa;
B) performing secondary hydrolysis reaction on the product solution of the primary hydrolysis reaction at 115-130 ℃ and-10 KPa, and condensing the gas after the secondary hydrolysis reaction to obtain a condensate and a non-condensable gas;
mixing the gas generated by the primary hydrolysis reaction, the non-condensable gas and alkali liquor, and performing neutralization reaction;
C) mixing the solution after the neutralization reaction with the condensate, performing first rectification on the mixed solution and the gas obtained by the neutralization reaction at-10 to 10KPa and the tower kettle temperature of 70 to 100 ℃, and performing second rectification on the tower kettle liquid obtained by the first rectification at 0 to 0.8MPa and the tower kettle temperature of 90 to 170 ℃ to obtain methanol; and performing third rectification on the tower top low-boiling-point substances obtained by the first rectification at the temperature of 0-80 KPa, the tower kettle temperature of 45-70 ℃ and the tower top temperature of-10-20 ℃ to obtain the methyl chloride.
In certain embodiments of the present invention, the glyphosate synthesis solution is prepared according to the following method:
under the action of triethylamine, glycine, paraformaldehyde and dialkyl phosphite are reacted in methanol to obtain glyphosate synthetic solution.
Preferably, the method specifically comprises the following steps:
a1) carrying out depolymerization reaction on methanol, triethylamine and paraformaldehyde at 40-55 ℃;
a2) performing addition reaction on the product after the depolymerization reaction and glycine at the temperature of 40-55 ℃;
a3) and carrying out condensation reaction on the product after the addition reaction and dialkyl phosphite at the temperature of 40-55 ℃ to obtain synthetic liquid.
In certain embodiments of the present invention, the mass ratio of the methanol to the triethylamine to the paraformaldehyde is 4750 to 5700: 1615-1710: 950. in certain embodiments, the mass ratio of methanol, triethylamine, and paraformaldehyde is 5200: 1630: 950 or 5400: 1650: 950. in some embodiments of the invention, the mass ratio of glycine to paraformaldehyde is 1045-1250: 950. in certain embodiments, the mass ratio of glycine to paraformaldehyde is 1200: 950 or 1250: 950. in certain embodiments of the present invention, the mass ratio of the dialkyl phosphite to the paraformaldehyde is 1995-2185: 950. in certain embodiments, the mass ratio of dialkyl phosphite to paraformaldehyde is 2060: 950 or 2100: 950. in certain embodiments of the invention, the dialkyl phosphite is dimethyl phosphite.
In certain embodiments of the invention, the temperature of the depolymerization reaction is 45 ℃ or 50 ℃. In certain embodiments of the invention, the temperature of the addition reaction is 50 ℃ or 45 ℃. In certain embodiments of the invention, the temperature of the condensation reaction is 50 ℃ or 45 ℃.
In certain embodiments of the present invention, the synthesis of the glyphosate synthesis solution is performed in a synthesis kettle.
And after the synthetic solution is obtained, acidifying the synthetic solution to obtain acidified glyphosate synthetic solution.
In certain embodiments of the invention, the acidifying agent used for the acidification is hydrochloric acid. In some embodiments of the invention, the acidification temperature is 35-55 ℃, and the acidification pressure is-10 KPa. In some embodiments, the acidification temperature is 40-55 ℃, 50 ℃ or 40 ℃, and the acidification pressure is-5 KPa or 0KPa or 5 KPa.
In certain embodiments of the invention, the acidification is performed in an acidification device.
After obtaining the acidified glyphosate synthetic solution, carrying out primary hydrolysis reaction on the acidified glyphosate synthetic solution at 90-112 ℃ and-5-20 KPa.
In certain embodiments of the present invention, the acidified glyphosate synthesis solution further comprises, prior to performing the first stage hydrolysis reaction: and cooling the acidified glyphosate synthesis solution. In some embodiments of the invention, the cooling temperature is 15-30 ℃. In certain embodiments of the invention, the cooling is performed in an acidification cooler.
In some embodiments of the present invention, the temperature of the primary hydrolysis reaction is 100-110 ℃, 108 ℃ or 100 ℃, and the pressure is 3-12 KPa, 10KPa or 5 KPa. In certain embodiments of the present invention, the first hydrolysis reaction is conducted in a first hydrolysis reaction unit.
And after the first-stage hydrolysis reaction is finished, performing a second-stage hydrolysis reaction on the product solution of the first-stage hydrolysis reaction at 115-130 ℃ and-10 KPa.
In some embodiments of the invention, the temperature of the secondary hydrolysis reaction is 115-125 ℃, 120 ℃ or 115 ℃, and the pressure is-5 KPa, -5KPa or 0 KPa. In certain embodiments of the invention, the secondary hydrolysis reaction is carried out in a secondary hydrolysis reaction apparatus. In certain embodiments of the present invention, the slurry after the secondary hydrolysis reaction is subjected to a subsequent crystallization step to prepare glyphosate.
And after the secondary hydrolysis reaction is finished, condensing the gas after the secondary hydrolysis reaction to obtain condensate and non-condensable gas.
In some embodiments of the invention, the condensation of the gas after the secondary hydrolysis reaction is a vacuum cooling at a pressure of not less than-70 KPa; or the condensation is water adding and cooling, and the temperature after water adding and cooling is 30-90 ℃. In certain embodiments of the present invention, the vacuum ramping pressure is-60 KPa. In certain embodiments of the invention, the condensation is carried out in a hydrolysis tail gas condenser. In some embodiments of the invention, the condensed condensate may be collected to a dilute methanol buffer tank.
Mixing the gas generated by the primary hydrolysis reaction, the non-condensable gas and alkali liquor, and carrying out neutralization reaction. In certain embodiments of the present invention, the gas generated by the acidification, the gas generated by the primary hydrolysis reaction, the non-condensable gas and the alkali liquor are mixed to perform a neutralization reaction. In certain embodiments of the invention, the lye comprises a sodium hydroxide solution. In certain embodiments of the present invention, the concentration of the lye by mass is not higher than 48%, preferably not higher than 10%, more preferably not higher than 5%. In certain embodiments of the invention, the gas produced by the primary hydrolysis reaction comprises methanol, methylal, methyl chloride, water, and hydrogen chloride. In certain embodiments of the invention, the non-condensable gas comprises methanol, methylal, methyl chloride, water and hydrogen chloride.
In some embodiments of the invention, the temperature of the neutralization reaction is 70-90 ℃ and the pressure is-5-10 KPa. In certain embodiments of the invention, the temperature of the neutralization reaction is 74 ℃ or 85 ℃ and the pressure is 0KPa or 5 KPa.
In certain embodiments of the invention, the neutralization is performed in a caustic tower.
And after the neutralization reaction is finished, mixing the solution after the neutralization reaction with the condensate, and performing first rectification on the mixed solution and the gas obtained by the neutralization reaction at-10 to 10KPa and the tower kettle temperature of 70 to 100 ℃. In certain embodiments of the invention, the mixing of the neutralized solution and the condensate is performed in a mixing device. In certain embodiments of the invention, the pressure of the first rectification is 5KPa or 0KPa and the temperature is 76 ℃ or 80 ℃. In some embodiments of the invention, the reflux ratio of the first rectification is 1-4: 1. in certain embodiments, the reflux ratio of the first rectification is 2.2 to 2.3: 1 or 2.2: 1. in certain embodiments of the invention, the first rectification is performed in a separation column. In certain embodiments of the invention, the gas from the first rectification comprises methanol, methylal, and methyl chloride.
In the invention, the tower bottom liquid obtained by the second rectification is subjected to second rectification at the temperature of 90-170 ℃ and under the pressure of 0-0.8 MPa to obtain the methanol. In some embodiments of the invention, the reflux ratio of the second rectification is 0-4: 1.
in certain embodiments of the invention, the second rectification comprises low pressure methanol rectification and high pressure methanol rectification. In some embodiments of the invention, the pressure of the low-pressure methanol rectification is 0-0.1 MPa, the temperature of a tower kettle is 90-130 ℃, and the reflux ratio is 0-4: 1 or 1.5: 1. in certain embodiments, the low pressure methanol rectification has a pressure of 0.01MPa and a column bottom temperature of 110 ℃ or 100 ℃. In certain embodiments of the invention, the low pressure methanol rectification is performed in a low pressure methanol column.
In some embodiments of the invention, the pressure of the high-pressure methanol rectification is 0.2-0.8 MPa, the temperature of a tower kettle is 135-170 ℃, and the reflux ratio is 1-4: 1. in certain embodiments of the invention, the pressure of the high pressure methanol distillation is 0.6MPa or 0.7MPa, the column bottom temperature is 165 ℃, and the reflux ratio is 2.5: 1. in certain embodiments of the invention, the high pressure methanol rectification is performed in a high pressure methanol column. In certain embodiments of the invention, the liquid after the high pressure methanol rectification may enter a wastewater treatment unit.
In the invention, the tower top low-boiling-point substance obtained by the first rectification is subjected to third rectification at the temperature of 0-80 KPa, the tower bottom temperature of 45-70 ℃ and the tower top temperature of-10-20 ℃ to obtain methyl chloride and methylal (a methyl chloride product is extracted from the tower top and a methylal product is extracted from the tower bottom). In certain embodiments of the invention, the pressure of the third rectification is 30KPa or 40KPa, the column still temperature is 55 ℃, and the overhead temperature is-14 ℃ or-17 ℃. In some embodiments of the invention, the reflux ratio of the third rectification is 0-3.5: 1. in certain embodiments, the reflux ratio of the third rectification is 1.0: 1 or 2: 1. in certain embodiments of the invention, the third rectification is performed in a demethanizer.
The source of the above-mentioned raw materials is not particularly limited in the present invention, and may be generally commercially available.
The method for recovering the hydrolysis tail gas of the glyphosate synthetic liquid has simple process, does not need steam stripping, can effectively recover byproducts and has lower cost.
The invention also provides a recovery system for the hydrolysis tail gas of the glyphosate synthetic fluid, which is used for implementing the recovery method and comprises the following steps:
a first-stage hydrolysis reaction device;
the second-stage hydrolysis reaction device is connected with a product solution outlet of the first-stage hydrolysis reaction device;
the hydrolysis tail gas condenser is connected with a gas outlet of the secondary hydrolysis reaction device;
the first gas inlet is connected with the gas outlet of the hydrolysis tail gas condenser; a second gas inlet of the alkaline tower is connected with a gas outlet of the primary hydrolysis reaction device;
the first liquid inlet is connected with the liquid outlet of the alkaline tower; a second liquid inlet of the mixing device is connected with a liquid outlet of the hydrolysis tail gas condenser;
the gas inlet is connected with the gas outlet of the alkaline tower; the liquid inlet of the separation tower is connected with the liquid outlet of the mixing device;
a methanol column connected to the liquid outlet of the separation column;
and the methane-removing tower is connected with the gas outlet of the separation tower.
See fig. 1. FIG. 1 is a schematic flow diagram of a system for recovering tail gas from the hydrolysis of glyphosate synthesis solution according to an embodiment of the present invention.
In some embodiments of the present invention, the recovery system of the hydrolysis tail gas of the glyphosate synthesis solution further comprises a synthesis kettle. The synthesis kettle is used for synthesizing glyphosate synthesis liquid. In an embodiment of the invention, the synthesis kettle is provided with a raw material inlet and a synthesis liquid outlet. The structure of the synthesis kettle is not particularly limited, and the synthesis kettle can be a conventional synthesis kettle.
In some embodiments of the present invention, the recovery system of the hydrolysis tail gas of the glyphosate synthetic fluid further comprises an acidification device. In certain embodiments of the invention, the acidification device is provided with a mixed liquor inlet, an acidulant inlet, an acidification liquor outlet, and a gas outlet. In certain embodiments of the invention, the mixed liquor inlet of the acidification device is connected to the mixed liquor outlet of the synthesis tank. The acidizing device is used for acidizing the synthetic fluid. In certain embodiments of the invention, the acidulation device is a tubular static mixer, model number SK, SV or SX, preferably SK.
In certain embodiments of the invention, the synthesis liquid discharged from the synthesis liquid outlet of the synthesis tank enters the acidification device through a synthesis liquid delivery pump. The structure of the synthetic liquid delivery pump is not particularly limited, and the synthetic liquid delivery pump can be a conventional centrifugal pump.
The recovery system of the glyphosate synthetic liquid hydrolysis tail gas provided by the invention comprises a primary hydrolysis reaction device. The first-stage hydrolysis reaction device is used for first-stage hydrolysis of the acidizing fluid and simultaneously separating light components such as methanol, methylal, methyl chloride and the like from the hydrolysis fluid. In certain embodiments of the present invention, the primary hydrolysis reaction device is provided with an acidified liquid inlet, a product solution outlet and a gas outlet. And an acidizing fluid inlet of the primary hydrolysis reaction device is connected with an acidizing fluid outlet of the acidizing device. In certain embodiments of the present invention, the first hydrolysis reaction device comprises a first hydrolysis reaction tower and a first hydrolysis reaction kettle.
In certain embodiments of the present invention, the first stage hydrolysis reaction tower is provided with an acidified liquid inlet, a product solution outlet, a gas outlet and a gas inlet. And an acidizing fluid inlet of the primary hydrolysis reaction tower is connected with an acidizing fluid outlet of the mixing device.
In certain embodiments of the present invention, the first stage hydrolysis reactor is provided with a product solution inlet, a product solution outlet and a gas outlet. And a product solution inlet of the first-stage hydrolysis reaction tower is connected with an acidizing fluid outlet of the acidizing device. And a product solution outlet of the primary hydrolysis reaction tower is connected with a product solution inlet of the primary hydrolysis reaction kettle. And a gas outlet of the primary hydrolysis reaction kettle is connected with a gas inlet of the primary hydrolysis reaction tower. And returning the gas discharged from the first-stage hydrolysis reaction kettle to the first-stage hydrolysis reaction tower.
The structures of the first-stage hydrolysis reaction tower and the first-stage hydrolysis reaction kettle are not particularly limited. In certain embodiments of the invention, the first hydrolysis reaction column is a corrosion-resistant packed column. In certain embodiments of the invention, the first hydrolysis reactor is an open glass lined reactor, a teflon lined reactor, or a graphite reactor.
In certain embodiments of the present invention, the recovery system of the hydrolysis tail gas of the glyphosate synthesis solution further comprises a hydrolysis reboiler. The hydrolysis reboiler is used for heating the first-stage hydrolysis reaction kettle. The connection mode of the hydrolysis reboiler is not particularly limited, and the first-stage hydrolysis reaction kettle can be heated. The structure of the hydrolysis reboiler is not particularly limited in the present invention, and in some embodiments of the present invention, the hydrolysis reboiler is a round block and hole graphite heat exchanger.
In certain embodiments of the present invention, the recovery system of the glyphosate synthesis solution hydrolysis tail gas further comprises an acidification cooler. See fig. 2. FIG. 2 is a schematic flow chart of a system for recovering tail gas from the hydrolysis of glyphosate synthesis solution according to another embodiment of the present invention. The acidification cooler is used for cooling the acidification liquid. And an acidizing fluid inlet of the acidizing cooler is connected with an acidizing fluid outlet of the mixing device, and an acidizing fluid outlet of the acidizing cooler is connected with an acidizing fluid inlet of the primary hydrolysis reaction tower. The present invention is not limited to the structure of the acidification liquid cooler, and in some embodiments, the acidification liquid discharged from the acidification liquid outlet of the mixing device enters the acidification cooler through the acidification liquid pump. The structure of the acidizing fluid pump is not particularly limited, and the acidizing fluid pump can be a conventional centrifugal pump or a magnetic pump.
The recovery system of the glyphosate synthetic liquid hydrolysis tail gas also comprises a secondary hydrolysis reaction device connected with a product solution outlet of the primary hydrolysis reaction device. The secondary hydrolysis reaction device is used for carrying out secondary hydrolysis reaction on the product solution of the primary hydrolysis reaction, and simultaneously separating residual light components, water, hydrogen chloride and the like. In certain embodiments of the present invention, the secondary hydrolysis reaction device is a secondary hydrolysis reaction kettle.
In certain embodiments of the invention, the secondary hydrolysis reactor is provided with a product solution inlet, a slurry outlet and a gas outlet. And a product solution inlet of the second-stage hydrolysis reaction kettle is connected with a product solution outlet of the first-stage hydrolysis reaction kettle. In certain embodiments of the invention, the slurry outlet of the secondary hydrolysis reactor is connected to the inlet of the crystallizer. The structure of the crystallizer is not particularly limited in the present invention, and may be a conventional crystallizer.
The structure of the secondary hydrolysis reactor is not particularly limited, and in some embodiments of the invention, the secondary hydrolysis reactor is an open glass lining reactor, a teflon lining reactor or a graphite reactor.
The recovery system of the glyphosate synthetic liquid hydrolysis tail gas also comprises a hydrolysis tail gas condenser connected with the gas outlet of the secondary hydrolysis reaction device. And the hydrolysis tail gas condenser is used for cooling tail gas after the secondary hydrolysis reaction. In certain embodiments of the invention, the hydrolysis tail gas condenser is provided with a gas inlet, a gas outlet and a condensate outlet. In certain embodiments of the present invention, the gas inlet of the hydrolysis tail gas condenser is connected to the gas outlet of the secondary hydrolysis reaction device. In certain embodiments, the gas inlet of the hydrolysis tail gas condenser is connected with the gas outlet of the secondary hydrolysis reaction kettle. The present invention is not particularly limited in its structure, and in some embodiments, the hydrolysis offgas condenser may be an acid-proof heat exchanger.
The recovery system of the glyphosate synthetic liquid hydrolysis tail gas provided by the invention also comprises an alkaline washing tower. The hydrolysis tail gas is acid gas, and the acid and alkali in the alkaline washing tower neutralize the acid and alkali, so that the range of equipment material selection of the rear system is wide, and the cost is lower. The alkaline tower is provided with a first gas inlet, a second gas inlet, a third gas inlet, a liquid outlet and a gas outlet. In certain embodiments of the invention, the first gas inlet of the alkaline tower is connected with the gas outlet of the hydrolysis tail gas condenser, and the second gas inlet of the alkaline tower is connected with the gas outlet of the primary hydrolysis reaction device. In certain embodiments of the invention, the second gas inlet of the caustic tower is connected to the gas outlet of the primary hydrolysis reaction tower. In certain embodiments of the invention, the third gas inlet of the caustic tower is connected to the gas outlet of the acidulation unit. The structure of the caustic tower is not particularly limited in the present invention, and in certain embodiments of the present invention, the caustic tower may be a packed tower.
The recovery system of the glyphosate synthesis solution hydrolysis tail gas also comprises a mixing device connected with a liquid outlet of the alkaline washing tower. In an embodiment of the invention, the mixing device is provided with a first liquid inlet, a second liquid inlet and a liquid outlet. And a first liquid inlet of the mixing device is connected with a liquid outlet of the alkaline washing tower. And a second liquid inlet of the mixing device is connected with a liquid outlet of the hydrolysis tail gas condenser. In certain embodiments of the invention, the mixing device is a tubular static mixer, of the type SK, SV or SX, preferably SK.
The recovery system for the hydrolysis tail gas of the glyphosate synthetic liquid also comprises a separation tower connected with a gas outlet of the alkaline washing tower. The separation tower is used for carrying out the first rectification, and the tower kettle diluted methanol and the tower top low-boiling-point substance can be obtained through the first rectification. In certain embodiments of the invention, the separation column is provided with a gas inlet, a liquid outlet, and a gas outlet. In certain embodiments of the invention, the gas inlet of the separation tower is connected to the gas outlet of the caustic tower. In certain embodiments of the invention, the liquid inlet of the separation column is connected to the liquid outlet of the mixing device. The present invention is not particularly limited in its structure, and in certain embodiments of the present invention, the separation column may be a conventional packed rectification column.
The recovery system of the glyphosate synthetic liquid hydrolysis tail gas provided by the invention also comprises a methanol tower connected with the liquid outlet of the separation tower. And the dilute methanol in the tower kettle in the separation tower is discharged from a liquid outlet of the separation tower and enters a methanol tower. In certain embodiments of the invention, the methanol column is provided with a liquid inlet and a liquid outlet. And the liquid inlet of the methanol tower is connected with the liquid outlet of the separation tower. The present invention is not particularly limited as to the structure of the methanol column, which may be a conventional packed rectification column in some embodiments of the invention.
In certain embodiments of the invention, the methanol column comprises a low pressure methanol column and a high pressure methanol column. The low-pressure methanol tower is provided with a liquid inlet, a liquid outlet and a methanol outlet. The high-pressure methanol tower is provided with a liquid inlet, a liquid outlet and a methanol outlet. The liquid inlet of the low-pressure methanol tower is connected with the liquid outlet of the separation tower; and the liquid inlet of the high-pressure methanol tower is connected with the liquid outlet of the low-pressure methanol tower. The present invention is not particularly limited with respect to the structure of the low pressure methanol column and the high pressure methanol column, and in some embodiments of the present invention, the low pressure methanol column may be a conventional packed rectification column. In certain embodiments of the invention, the high pressure methanol column may be a conventional packed rectification column.
The recovery system for the glyphosate synthesis solution hydrolysis tail gas provided by the invention also comprises a methane-removing tower connected with the gas outlet of the separation tower. The chloromethane is refined by rectification of a chloromethane removing tower, so that the post-system treatment cost is reduced, and the methylal is recovered, so that the methanol consumption is reduced. In certain embodiments of the invention, the gas inlet of the de-chloromethane column is connected to the gas outlet of the separation column. The present invention is not particularly limited in terms of the structure of the demethanizer, and in some embodiments of the present invention, the demethanizer may be a conventional packed rectification column.
The recovery system for the hydrolysis tail gas of the glyphosate synthetic fluid provided by the invention is simple in process, does not contain a stripping tower, can effectively recover byproducts, and is low in cost.
In order to further illustrate the present invention, the following will describe the method and system for recovering tail gas from the hydrolysis of glyphosate synthesis solution in detail with reference to the examples, but they should not be construed as limiting the scope of the present invention.
The starting materials used in the following examples are all generally commercially available.
Example 1
Experiments were conducted on the recovery system for the tail gas from the hydrolysis of glyphosate synthesis solution as described in figure 2:
synthesizing glyphosate synthetic solution in a synthesis kettle:
the raw materials comprise: 5200 parts by weight of methanol, 1630 parts by weight of triethylamine, 950 parts by weight of paraformaldehyde, 1200 parts by weight of glycine and 2060 parts by weight of dimethyl phosphite.
a1) Carrying out depolymerization reaction on methanol, triethylamine and paraformaldehyde at 45 ℃;
a2) performing addition reaction on the product after the depolymerization reaction and glycine at 50 ℃;
a3) and carrying out condensation reaction on the product after the addition reaction and dialkyl phosphite at 50 ℃ to obtain synthetic liquid.
The synthetic solution and hydrochloric acid were mixed in an acidification device (static mixer) and acidified at 50 ℃ under 0 KPa. After acidification is completed, the mixture is cooled in an acidification cooler. And (3) feeding the cooled acidified liquid into a first-stage hydrolysis reaction tower and a first-stage hydrolysis kettle to perform a first-stage hydrolysis reaction, wherein the temperature of the first-stage hydrolysis reaction is 108 ℃, and the pressure is 10 KPa. And performing secondary hydrolysis reaction on the product solution of the primary hydrolysis reaction in a secondary hydrolysis kettle, wherein the temperature of the secondary hydrolysis reaction is 120 ℃, and the pressure is-5 KPa.
And (3) carrying out vacuum cooling on the gas after the secondary hydrolysis reaction in a hydrolysis tail gas condenser, wherein the pressure of the vacuum cooling is-60 KPa. And (2) gas (comprising methanol, methylal, methyl chloride, water and hydrogen chloride) discharged from the hydrolysis tail gas condenser, gas (comprising methanol, methylal, methyl chloride, water and hydrogen chloride) discharged from the primary hydrolysis reaction tower and gas discharged from the static mixer enter an alkaline tower, and are subjected to neutralization reaction with a sodium hydroxide solution with the mass concentration of 5% in the alkaline tower, wherein the temperature of the neutralization reaction is 74 ℃ and the pressure is 0 KPa.
Mixing the solution after the neutralization reaction with the condensate, and then feeding the mixture into a separation tower; and (2) gas discharged from the top of the alkaline tower also enters a separation tower for first rectification separation, the temperature of the tower kettle of the separation tower is 76 ℃, the pressure of the top of the separation tower is 5KPa, and the reflux ratio of the top of the separation tower is 2.2: 1.
and (2) introducing gas (comprising methanol, methylal and methyl chloride) evaporated from the top of the separation tower into a methane-dechlorinating tower, recovering the methyl chloride and the methylal, wherein the temperature of the top of the methane-dechlorinating tower is-14 ℃, the temperature of a tower kettle is 55 ℃, the pressure of the top of the tower is 30KPa, and the reflux ratio is 1.5: 1.
the tower bottom components of the separation tower sequentially enter a low-pressure methanol tower and a high-pressure methanol tower to recover methanol, the pressure of the low-pressure methanol tower is 0.01MPa, the temperature of a tower kettle is 110 ℃, and the reflux ratio is 1.5: 1, the pressure of a high-pressure methanol tower is 0.6MPa, the temperature of a tower kettle is 165 ℃, and the reflux ratio is 2.5: 1.
the detection shows that the recovery rate of the chloromethane is more than 99 percent, the purity (without air) is about 97.5 percent, and the dimethyl ether is about 2.5 percent; the recovery rate of methylal is more than 99 percent, and the purity is more than 85 percent; the recovery rate of the methanol is more than 99 percent, and the purity is more than 99.5 percent; the methanol consumption of each ton of glyphosate is 260kg, the steam consumption of each ton of glyphosate is 6.2t, and the sulfuric acid consumption of each ton of chloromethane is 55 kg.
Example 2
Experiments were conducted on the recovery system for the tail gas from the hydrolysis of glyphosate synthesis solution as described in figure 2:
synthesizing glyphosate synthetic solution in a synthesis kettle:
the raw materials comprise: 5400 parts by weight of methanol, 1650 parts by weight of triethylamine, 950 parts by weight of paraformaldehyde, 1250 parts by weight of glycine and 2100 parts by weight of dimethyl phosphite.
a1) Carrying out depolymerization reaction on methanol, triethylamine and paraformaldehyde at 50 ℃;
a2) performing addition reaction on the product after the depolymerization reaction and glycine at the temperature of 45 ℃;
a3) and carrying out condensation reaction on the product after the addition reaction and dialkyl phosphite at the temperature of 45 ℃ to obtain synthetic liquid.
The synthetic solution and hydrochloric acid were mixed in an acidification device (static mixer) and acidified at 40 ℃ under a pressure of 5 KPa. After acidification is completed, the mixture is cooled in an acidification cooler. And (3) feeding the cooled acidified liquid into a first-stage hydrolysis reaction tower and a first-stage hydrolysis kettle to perform a first-stage hydrolysis reaction, wherein the temperature of the first-stage hydrolysis reaction is 100 ℃, and the pressure is 5 KPa. And performing secondary hydrolysis reaction on the product solution of the primary hydrolysis reaction in a secondary hydrolysis kettle, wherein the temperature of the secondary hydrolysis reaction is 115 ℃, and the pressure is-5 KPa.
And (3) carrying out vacuum cooling on the gas after the secondary hydrolysis reaction in a hydrolysis tail gas condenser, wherein the pressure of the vacuum cooling is-60 KPa. And (2) gas (comprising methanol, methylal, methyl chloride, water and hydrogen chloride) discharged from the hydrolysis tail gas condenser, gas (comprising methanol, methylal, methyl chloride, water and hydrogen chloride) discharged from the primary hydrolysis reaction tower and gas discharged from the static mixer enter an alkaline tower, and are subjected to neutralization reaction with a sodium hydroxide solution with the mass concentration of 5% in the alkaline tower, wherein the temperature of the neutralization reaction is 85 ℃, and the pressure is 5 KPa.
Mixing the solution after the neutralization reaction with the condensate, and then feeding the mixture into a separation tower; gas discharged from the top of the alkaline tower also enters a separation tower for first rectification separation, the temperature of a tower kettle of the separation tower is 80 ℃, the pressure of the top of the separation tower is 0KPa, and the reflux ratio of the top of the separation tower is 2.2: 1.
and (2) introducing gas (comprising methanol, methylal and methyl chloride) evaporated from the top of the separation tower into a methane-dechlorinating tower, recovering the methyl chloride and the methylal, wherein the temperature of the top of the methane-dechlorinating tower is-17 ℃, the temperature of a tower kettle is 55 ℃, the pressure of the top of the tower is 40KPa, and the reflux ratio is 2: 1.
the tower bottom components of the separation tower sequentially enter a low-pressure methanol tower and a high-pressure methanol tower to recover methanol, the pressure of the low-pressure methanol tower is 0.01MPa, the temperature of a tower kettle is 100 ℃, and the reflux ratio is 1.5: 1, the pressure of a high-pressure methanol tower is 0.7MPa, the temperature of a tower kettle is 165 ℃, and the reflux ratio is 2.5: 1.
the detection shows that the recovery rate of the chloromethane is more than 99 percent, the purity (without air) is about 97.5 percent, and the dimethyl ether is about 2.5 percent; the recovery rate of methylal is more than 99 percent, and the purity is more than 85 percent; the recovery rate of the methanol is more than 99 percent, and the purity is more than 99.5 percent; 265kg of methanol is consumed by each ton of glyphosate, 6.1t of steam is consumed by each ton of glyphosate, and 55kg of sulfuric acid is consumed by each ton of methyl chloride.
Comparative example 1
After carrying out neutralization reaction on dilute methanol and liquid caustic soda with the mass concentration of 40% in a static mixer, preheating to 60-80 ℃ by using recovered methanol and steam condensate water, rectifying in a partition wall tower through gas-liquid two phases, controlling the temperature of the top of a methylal side tower at 42 ℃, keeping the pressure at normal pressure and the reflux ratio at 5, condensing gas phase extracted from the top of the tower to obtain a methylal product, and removing chloromethane from non-condensable gas (crude chloromethane) to obtain a chloromethane recovery device; the temperature of the top of the methanol side tower is controlled at 64 ℃, the pressure is normal, the reflux ratio is 1.5, the methanol product is extracted from the top of the tower, and the mixture of methanol and water is extracted from the middle lower side of the tower to the high-pressure methanol tower; removing the tower kettle waste water to an environment-friendly station after heat exchange; the temperature at the top of the high-pressure methanol tower is controlled at 120 ℃, the pressure is controlled at 0.55MPa, the reflux ratio is 3.5, the gas phase at the top of the high-pressure methanol tower is used as a heat source for the partition wall tower, the condensate is a methanol product, and the waste water at the bottom of the tower is subjected to heat exchange and then is discharged to an environmental protection station.
The recovery rate of methanol is more than 98%, the purity is more than 99.5%, 330kg of methanol is consumed by each ton of glyphosate, 7.0t of steam is consumed by each ton of glyphosate, and 130kg of sulfuric acid is consumed by each ton of methyl chloride.
The results of comparing the mass of methyl chloride and methylal obtained in examples 1 to 2 with that obtained in comparative example 1 are shown in tables 1 and 2:
TABLE 1 comparison of the quality of methyl chloride obtained in examples 1-2 and comparative example 1
| Methyl chloride | Dimethyl ether | Methylal | Methanol | Water (W) | |
| Example 1 | 97.5 | 2.5 | Not detected out | Not detected out | Not detected out |
| Comparative example 1 | 93.3 | 2.5 | 2.5 | 1.5 | 0.2 |
TABLE 2 results of comparing the qualities of the formals obtained in examples 1 to 2 and comparative example 1
| Methyl chloride | Methylal | Methanol | Water (W) | |
| Example 1 | <0.1 | 85 | 14.8 | 0.1 |
| Comparative example 1 | ≈3 | 85 | 11.9 | 0.1 |
The above description of the embodiments is only intended to facilitate the understanding of the method of the invention and its core idea. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. A method for recovering tail gas generated by hydrolyzing glyphosate synthetic liquid comprises the following steps:
A) carrying out primary hydrolysis reaction on the acidified glyphosate synthetic solution at 90-112 ℃ and-5-20 KPa;
B) performing secondary hydrolysis reaction on the product solution of the primary hydrolysis reaction at 115-130 ℃ and-10 KPa, and condensing the gas after the secondary hydrolysis reaction to obtain a condensate and a non-condensable gas;
mixing the gas generated by the primary hydrolysis reaction, the non-condensable gas and alkali liquor, and performing neutralization reaction;
C) mixing the solution after the neutralization reaction with the condensate, performing first rectification on the mixed solution and the gas obtained by the neutralization reaction at-10 to 10KPa and the tower kettle temperature of 70 to 100 ℃, and performing second rectification on the tower kettle liquid obtained by the first rectification at 0 to 0.8MPa and the tower kettle temperature of 90 to 170 ℃ to obtain methanol; and performing third rectification on the tower top low-boiling-point substances obtained by the first rectification at the temperature of 0-80 KPa, the tower kettle temperature of 45-70 ℃ and the tower top temperature of-10-20 ℃ to obtain methyl chloride and methylal.
2. The recovery method as set forth in claim 1, wherein in the step a), the glyphosate synthetic fluid is prepared according to the following method:
a1) carrying out depolymerization reaction on methanol, triethylamine and paraformaldehyde at 40-55 ℃;
a2) performing addition reaction on the product after the depolymerization reaction and glycine at the temperature of 40-55 ℃;
a3) and carrying out condensation reaction on the product after the addition reaction and dialkyl phosphite at the temperature of 40-55 ℃ to obtain synthetic liquid.
3. The recovery method according to claim 1, wherein the acidification temperature in step A) is 35-55 ℃, and the acidification pressure is-10 KPa.
4. The recovery method according to claim 1, wherein in the step B), the condensation is vacuum cooling, and the pressure of the vacuum cooling is not less than-70 KPa; or the condensation is water adding and cooling, and the temperature after water adding and cooling is 30-90 ℃.
5. The recovery method according to claim 1, wherein in the step B), the temperature of the neutralization reaction is 70 to 90 ℃ and the pressure is-5 to 10 KPa.
6. The recovery method according to claim 1, wherein in the step C), the reflux ratio of the first rectification is 1-4: 1; the reflux ratio of the second rectification is 0-4: 1; the reflux ratio of the third rectification is 1-3.5: 1.
7. the recovery method according to claim 1, wherein in step C), the second rectification comprises low pressure methanol rectification and high pressure methanol rectification;
the pressure of the low-pressure methanol rectification is 0.1-0.3 MPa, the temperature of a tower kettle is 85-120 ℃, and the reflux ratio is 1-4: 1;
the pressure of the high-pressure methanol rectification is 0.4-0.8 MPa, the temperature of a tower kettle is 135-170 ℃, and the reflux ratio is 1-4: 1.
8. a recovery system of glyphosate synthetic fluid hydrolysis tail gas includes:
a first-stage hydrolysis reaction device;
the second-stage hydrolysis reaction device is connected with a product solution outlet of the first-stage hydrolysis reaction device;
the hydrolysis tail gas condenser is connected with a gas outlet of the secondary hydrolysis reaction device;
the first gas inlet is connected with the gas outlet of the hydrolysis tail gas condenser; a second gas inlet of the alkaline tower is connected with a gas outlet of the primary hydrolysis reaction device;
the first liquid inlet is connected with the liquid outlet of the alkaline tower; a second liquid inlet of the mixing device is connected with a liquid outlet of the hydrolysis tail gas condenser;
the gas inlet is connected with the gas outlet of the alkaline tower; the liquid inlet of the separation tower is connected with the liquid outlet of the mixing device;
a methanol column connected to the liquid outlet of the separation column;
and the methane-removing tower is connected with the gas outlet of the separation tower.
9. The recycling system according to claim 8, wherein the primary hydrolysis reaction device comprises a primary hydrolysis reaction tower and a primary hydrolysis reaction kettle;
the product solution outlet of the first-stage hydrolysis reaction tower is connected with the product solution inlet of the first-stage hydrolysis reaction kettle;
the gas outlet of the primary hydrolysis reaction kettle is connected with the gas inlet of the primary hydrolysis reaction tower;
the second-stage hydrolysis reaction device is a second-stage hydrolysis reaction kettle;
the product solution inlet of the second-stage hydrolysis reaction kettle is connected with the product solution outlet of the first-stage hydrolysis reaction kettle;
and a gas inlet of the hydrolysis tail gas condenser is connected with a gas outlet of the secondary hydrolysis reaction kettle.
10. A recovery system as claimed in claim 8, in which the methanol column comprises a low pressure methanol column and a high pressure methanol column;
the liquid inlet of the low-pressure methanol tower is connected with the liquid outlet of the separation tower;
and the liquid inlet of the high-pressure methanol tower is connected with the liquid outlet of the low-pressure methanol tower.
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Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1629112A (en) * | 2002-07-23 | 2005-06-22 | 浙江新安化工集团股份有限公司 | Clean reclaiming process for byproduct chloromethane of glyphosate acid |
| CN1939927A (en) * | 2006-09-19 | 2007-04-04 | 浙江新安化工集团股份有限公司 | Continuous synthesis of glyphosate by dimethyl ester |
| CN101786938A (en) * | 2010-03-15 | 2010-07-28 | 衡阳莱德生物药业有限公司 | Method for recycling chloromethane during production of glyphosate by using glycine method |
| CN101875596A (en) * | 2009-04-28 | 2010-11-03 | 苏州佳辉化工有限公司 | Process for reclaiming chloromethane |
| CN102757462A (en) * | 2012-07-30 | 2012-10-31 | 浙江金帆达生化股份有限公司 | Continuous production method of glyphosate crystal |
| CN103736384A (en) * | 2014-01-27 | 2014-04-23 | 山东潍坊润丰化工股份有限公司 | Treatment process of glyphosate hydrolyzing tail gas |
| CN103752158A (en) * | 2014-01-27 | 2014-04-30 | 山东潍坊润丰化工股份有限公司 | Method for treating glyphosate hydrolyzing tail gas |
| CN104353339A (en) * | 2014-10-30 | 2015-02-18 | 江西金龙化工有限公司 | Method for continuously recovering by-products from tail gas obtained by hydrolyzing glyphosate |
| CN108404637A (en) * | 2018-04-20 | 2018-08-17 | 湖北泰盛化工有限公司 | A kind of alkyl esterification method glyphosate hydrolyzing tail gas reclaimer and technique |
| CN110698320A (en) * | 2019-11-05 | 2020-01-17 | 山东潍坊润丰化工股份有限公司 | Continuous recovery device and continuous recovery process for glyphosate hydrolyzed gas phase |
| CN211753891U (en) * | 2020-03-16 | 2020-10-27 | 浙江新安化工集团股份有限公司 | Recovery system of tail gas is hydrolysised to glyphosate synthetic liquid |
-
2020
- 2020-03-16 CN CN202010182047.XA patent/CN111269089A/en active Pending
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1629112A (en) * | 2002-07-23 | 2005-06-22 | 浙江新安化工集团股份有限公司 | Clean reclaiming process for byproduct chloromethane of glyphosate acid |
| CN1939927A (en) * | 2006-09-19 | 2007-04-04 | 浙江新安化工集团股份有限公司 | Continuous synthesis of glyphosate by dimethyl ester |
| CN101875596A (en) * | 2009-04-28 | 2010-11-03 | 苏州佳辉化工有限公司 | Process for reclaiming chloromethane |
| CN101786938A (en) * | 2010-03-15 | 2010-07-28 | 衡阳莱德生物药业有限公司 | Method for recycling chloromethane during production of glyphosate by using glycine method |
| CN102757462A (en) * | 2012-07-30 | 2012-10-31 | 浙江金帆达生化股份有限公司 | Continuous production method of glyphosate crystal |
| CN103736384A (en) * | 2014-01-27 | 2014-04-23 | 山东潍坊润丰化工股份有限公司 | Treatment process of glyphosate hydrolyzing tail gas |
| CN103752158A (en) * | 2014-01-27 | 2014-04-30 | 山东潍坊润丰化工股份有限公司 | Method for treating glyphosate hydrolyzing tail gas |
| CN104353339A (en) * | 2014-10-30 | 2015-02-18 | 江西金龙化工有限公司 | Method for continuously recovering by-products from tail gas obtained by hydrolyzing glyphosate |
| CN108404637A (en) * | 2018-04-20 | 2018-08-17 | 湖北泰盛化工有限公司 | A kind of alkyl esterification method glyphosate hydrolyzing tail gas reclaimer and technique |
| CN110698320A (en) * | 2019-11-05 | 2020-01-17 | 山东潍坊润丰化工股份有限公司 | Continuous recovery device and continuous recovery process for glyphosate hydrolyzed gas phase |
| CN211753891U (en) * | 2020-03-16 | 2020-10-27 | 浙江新安化工集团股份有限公司 | Recovery system of tail gas is hydrolysised to glyphosate synthetic liquid |
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