CN216427170U - Deep recovery system for chloromethane - Google Patents
Deep recovery system for chloromethane Download PDFInfo
- Publication number
- CN216427170U CN216427170U CN202121805803.6U CN202121805803U CN216427170U CN 216427170 U CN216427170 U CN 216427170U CN 202121805803 U CN202121805803 U CN 202121805803U CN 216427170 U CN216427170 U CN 216427170U
- Authority
- CN
- China
- Prior art keywords
- tower
- methyl chloride
- gas
- sulfuric acid
- concentrated sulfuric
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Treating Waste Gases (AREA)
Abstract
The utility model discloses a deep recovery system of methyl chloride, which belongs to the technical field of chemical industry and comprises a methyl chloride crude product recovery device, a methyl chloride crude product refining device and a methyl chloride deep recovery device, wherein the methyl chloride deep recovery device comprises: the absorption tower is connected with a non-condensable gas outlet of the condensing device; the desorption tower is connected with the tower liquid outlet of the absorption tower; with the scrubbing tower that absorption tower top gas port links to each other for methyl chloride gas can carry out follow-up drying, compression, condensation, and burn tail gas, thereby ensure that tail gas treatment is thorough, solved among the prior art in the clean recovery process of methyl chloride, the separation recovery effect is not good enough problem.
Description
Technical Field
The utility model belongs to the technical field of chemical industry, and particularly relates to a deep recovery system of methyl chloride.
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 company in America, and the glyphosate in China is mainly produced by adopting an alkyl ester method taking glycine and dimethyl phosphite as main raw materials. The alkyl ester method for producing glyphosate generates a large amount of tail gas in the production of raw materials, namely dimethyl phosphite and glyphosate generated by hydrolysis (the tail gas generated in the production of dimethyl phosphite and the tail gas generated in the hydrolysis of glyphosate synthetic fluid are both methyl chloride mixed gas).
Methyl chloride is colorless, easy to liquefy and combustible toxic gas and is used for synthesizing methyl chlorosilane monomers, producing carboxymethyl cellulose, chloroprene rubber and other products. If the glyphosate hydrolysis tail gas and the dimethyl phosphite production tail gas are directly discharged, not only is the resource waste caused, but also the production cost of enterprises is increased; but also has adverse effect on the environment, and violates the idea of green chemical industry.
Patent CN101012146B discloses a method for separating and recovering methyl chloride from a mixed gas of methyl chloride, in which at least two adsorption tower systems filled with adsorbents are used, the mixed gas containing methyl chloride is subjected to pressure swing adsorption processes of adsorption, pressure equalization and desorption in each adsorption tower in a time sequence staggered manner to remove impurities so as to obtain a methyl chloride product, but the method has insufficient gas treatment, and the methyl chloride cannot be completely compressed into a gas state due to the limitation of gas compression ratio, and the methyl chloride tail gas also contains methyl chloride which cannot be recovered.
Disclosure of Invention
In order to overcome the problem that in the prior art, in the clean recovery process of methyl chloride, separation recovery efficiency and effect are poor, provide a degree of depth recovery system of methyl chloride, it is through the further advanced treatment to gaseous behind the methyl chloride processing, improves the effect of tail gas treatment, can retrieve more methyl chloride, environmental protection more.
The utility model discloses a deep recovery system of methyl chloride, which comprises a methyl chloride crude product recovery device, a methyl chloride crude product refining device and a methyl chloride deep recovery device, wherein the methyl chloride crude product recovery device comprises a methyl chloride removal tower, and the methyl chloride crude product refining device comprises: the concentrated sulfuric acid drying tower is connected with a discharge port at the top of the methane-removing tower and a gas outlet of a chloromethane alkali washing tower; the condensing device is connected with the gas outlet of the concentrated sulfuric acid drying tower; the methyl chloride degree of depth recovery unit includes: the absorption tower is connected with a non-condensable gas outlet of the condensing device; the desorption tower is connected with the tower liquid outlet of the absorption tower; and the water washing tower is connected with the top air outlet of the absorption tower.
Drying the gaseous chloromethane crude product in a concentrated sulfuric acid drying tower to obtain dry gaseous chloromethane; then, condensing the dry gaseous methyl chloride in a condensing device to obtain a liquid methyl chloride product; the methyl chloride tail gas enters an absorption tower again and is absorbed by methanol to obtain tower bottom liquid and tail gas of the absorption tower; then the tower bottom liquid enters a desorption tower, and the temperature is raised by a reboiler to desorb the methyl chloride, so that the tower bottom liquid (methanol) of the desorption tower and the methyl chloride gas are obtained; carrying out subsequent drying, compression and condensation on the chloromethane gas; and the gas phase tail gas of the absorption tower enters a water washing tower to wash off methanol and is conveyed to an incineration device for incineration, so that the tail gas is ensured to be thoroughly treated.
Preferably, the device for recovering the crude methyl chloride product comprises a device for recovering the crude methyl chloride product from the tail gas generated in the glyphosate production and a device for recovering the crude methyl chloride product from the tail gas generated in the dimethyl phosphite production.
Preferably, the device for recovering the crude methyl chloride product from the glyphosate production tail gas comprises: a neutralization tower; the stripper is connected with the tower bottom liquid outlet of the neutralization tower, and a hydrolysis condensate liquid inlet is formed in a connecting pipeline between the tower bottom liquid outlet of the neutralization tower and the stripper; the separation tower is respectively connected with the gas outlet of the neutralization tower and the gas outlet of the stripping tower; and the methane-removing tower is connected with a discharge hole at the top of the separation tower.
Tail gas generated in a hydrolysis procedure in the production process of glyphosate is firstly mixed with alkali liquor in a neutralization tower for reaction to obtain tower bottom liquid of the neutralization tower and neutralized tail gas; then, regulating the pH value of the tower bottom liquid discharged from the neutralizing tower by using a glyphosate acidification synthetic liquid hydrolysis condensate (dilute methanol) (the pH value is controlled to be 6-14), and carrying out steam stripping on the tower bottom liquid of the neutralizing tower after the pH value regulation in a stripping tower to obtain a gas phase product and the tower bottom liquid of the stripping tower; then, rectifying and separating the neutralized tail gas and the gas-phase product in a separation tower to obtain a gas phase at the top of the separation tower and a tower bottom liquid of the separation tower; then, rectifying and separating the gas phase at the top of the separation tower in a methane-removing tower to obtain a gaseous chloromethane crude product and a methane-removing tower bottom liquid; the chloromethane crude product obtained by the scheme has lower moisture, methanol, methylal and other components, and the use amount of sulfuric acid in a drying process and the treatment amount of waste sulfuric acid are reduced.
Preferably, the device for recovering the crude methyl chloride product from the tail gas generated in the dimethyl phosphite production comprises: a concentrated acid absorption tower; the concentrated hydrochloric acid absorption tower is connected with an air outlet at the top of the concentrated acid absorption tower; the dilute hydrochloric acid absorption tower is connected with a gas outlet at the top of the concentrated hydrochloric acid absorption tower; the water absorption tower is connected with a gas outlet at the top of the dilute hydrochloric acid absorption tower; the alkaline washing tower is connected with an air outlet of the water absorption tower; a chloromethane water scrubber connected with the top gas outlet of the alkaline tower; and the methyl chloride alkaline washing tower is connected with an air outlet of the methyl chloride water washing tower.
Tail gas generated in the production process of dimethyl phosphite firstly passes through a concentrated acid absorption tower, a concentrated hydrochloric acid absorption tower, a dilute hydrochloric acid absorption tower and a water absorption tower to be connected in series to absorb hydrogen chloride therein, so as to obtain hydrochloric acid with different concentrations in a tower kettle and a tower top gas phase; the gas phase at the tower top is ensured to be completely absorbed by the hydrogen chloride through an alkali washing tower; then the gas phase of the alkaline washing tower enters a chloromethane water washing tower to absorb methanol in the mixed gas, so that a tower top gas phase and a tower kettle liquid phase are obtained; then absorbing methanol and acid gas in the mixed gas by a liquid phase at the top of a chloromethane water washing tower through a chloromethane alkaline washing tower to obtain a liquid phase at the bottom of the tower and a gaseous chloromethane crude product at the top of the tower; the hydrogen chloride can be recycled by the scheme.
Preferably, the methyl chloride washing tower comprises a plurality of stages of methyl chloride washing towers which are arranged in series, and the air outlet of the upper stage of methyl chloride washing tower is connected with the air inlet of the lower stage of methyl chloride washing tower.
Preferably, the concentrated sulfuric acid drying tower comprises a plurality of stages of concentrated sulfuric acid drying towers which are connected in series, and an air outlet of the upper stage of concentrated sulfuric acid drying tower is connected with an air inlet of the lower stage of concentrated sulfuric acid drying tower.
Preferably, the condensing device comprises multistage condensers which are arranged in series, and a non-condensable gas outlet of the upper-stage condenser is connected with a gas port of the lower-stage condenser.
Preferably, the system is still including setting up the top of the tower discharge gate of dechlorination methane tower with methyl chloride buffer tank between the concentrated sulfuric acid drying tower, methyl chloride buffer tank's feed inlet with the top of the tower discharge gate of dechlorination methane tower is connected, methyl chloride buffer tank's discharge gate with the air inlet of concentrated sulfuric acid drying tower is connected.
Preferably, the system further comprises a methyl chloride gas cabinet arranged between a discharge port of the methyl chloride alkaline tower and the concentrated sulfuric acid drying tower, a feed port of the methyl chloride gas cabinet is connected with a discharge port of the top of the dechlorination methane tower, and a discharge port of the methyl chloride gas cabinet is connected with an air inlet of the concentrated sulfuric acid drying tower.
Therefore, the utility model has the following beneficial effects: (1) by neutralizing, stripping and multi-effect rectifying tail gas in glyphosate production, the recovery rate of methyl chloride is improved, the content of water, methanol and methylal in a methyl chloride crude product is greatly reduced, the rectified methyl chloride gas crude product does not contain other components except methyl chloride, dimethyl ether and air basically, the quality of the methyl chloride crude product is improved, the problem of higher sulfuric acid consumption in the subsequent sulfuric acid drying of the methyl chloride crude product caused by mixing low-boiling-point substances such as methanol and methylal into the methyl chloride gas can be avoided, and the use amount of sulfuric acid in a downstream sulfuric acid drying process and the treatment amount of waste sulfuric acid can be reduced by more than 55%; moreover, the rectified chloromethane crude product does not need water washing and alkali washing processes, so that the amount of wastewater can be reduced, the investment of equipment and electrometers in corresponding processes can be reduced, and the investment cost can be reduced; (2) the water-solubility difference of the hydrogen chloride and the chloromethane is utilized, and the hydrogen chloride in the tail gas generated in the production of the dimethyl phosphite is absorbed and separated by water, so that the separation method is simple, and the byproduct hydrochloric acid is obtained simultaneously, thereby saving the cost; (3) the deep recovery of the chloromethane tail gas reduces the waste of resources and further saves the cost; the safety of tail gas incineration treatment is improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
FIG. 1 is a simplified flow diagram of a methyl chloride cleaning and recycling system provided by an embodiment of the utility model.
FIG. 2 is a flow chart of a process for recovering methyl chloride crude product from glyphosate production tail gas according to an embodiment of the present invention.
FIG. 3 is a process flow diagram of the first half of the process for recovering crude methyl chloride from the tail gas from dimethyl phosphite production according to the embodiment of the present invention.
FIG. 4 is a flow chart of a latter half process for recovering crude methyl chloride from tail gas from dimethyl phosphite production according to the embodiment of the present invention.
FIG. 5 is a flow chart of a process for refining crude chloromethane provided by the embodiment of the present invention.
Fig. 6 is a process flow diagram of a methyl chloride deep recovery system provided by the embodiment of the utility model.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious 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 utility model provides a deep recovery system of methyl chloride, which comprises:
device for recovering methyl chloride crude product from glyphosate production tail gas comprises: a neutralization tower; the stripper is connected with the tower bottom liquid outlet of the neutralization tower, and a hydrolysis condensate liquid inlet is formed in a connecting pipeline between the tower bottom liquid outlet of the neutralization tower and the stripper; the separation tower is respectively connected with the gas outlet of the neutralization tower and the gas outlet of the stripping tower; the methane-removing tower is connected with a discharge hole at the top of the separation tower;
methyl chloride crude product device is retrieved to dimethyl phosphite production tail gas includes: a concentrated acid absorption tower; the concentrated hydrochloric acid absorption tower is connected with an air outlet at the top of the concentrated acid absorption tower; the dilute hydrochloric acid absorption tower is connected with a gas outlet at the top of the concentrated hydrochloric acid absorption tower; the water absorption tower is connected with a gas outlet at the top of the dilute hydrochloric acid absorption tower; the alkaline washing tower is connected with an air outlet of the water absorption tower; a chloromethane water scrubber connected with the top gas outlet of the alkaline tower; and the methyl chloride alkaline washing tower is connected with an air outlet of the methyl chloride water washing tower.
Dry condensing equipment of methyl chloride crude includes: the concentrated sulfuric acid drying tower is connected with a discharge port at the top of the methane-removing tower and a gas outlet of the chloromethane alkali washing tower; and the condensing device is connected with the gas outlet of the concentrated sulfuric acid drying tower.
Methyl chloride degree of depth recovery unit includes: the absorption tower is connected with a non-condensable gas outlet of the condensing device; the desorption tower is connected with the tower liquid outlet of the absorption tower; and the water washing tower is connected with the top air outlet of the absorption tower.
Referring to fig. 1, fig. 1 is a simplified flow diagram of a methyl chloride cleaning and recycling system provided by an embodiment of the utility model. Wherein 1 represents a neutralization tower, 2 represents a stripping tower, 3 represents a separation tower, 4 represents a methane-removing tower, 5 represents a concentrated acid absorption tower, 6 represents a concentrated hydrochloric acid absorption tower, 7 represents a dilute hydrochloric acid absorption tower, 8 represents a water absorption tower, 9 represents an alkaline tower, 10 represents a methyl chloride water washing tower, 11 represents a methyl chloride alkaline washing tower, 12 represents a concentrated sulfuric acid drying tower, 13 represents a condensing device, 14 represents an absorption tower, 15 represents a desorption tower, and 16 represents a water washing tower.
The cleaning and recycling system provided by the utility model comprises a neutralization tower 1, a stripping tower 2, a separation tower 3, a methane-removing tower 4, a concentrated acid absorption tower 5, a concentrated hydrochloric acid absorption tower 6, a dilute hydrochloric acid absorption tower 7, a water absorption tower 8, an alkaline washing tower 9, a chloromethane water washing tower 10, a chloromethane alkaline washing tower 11, a concentrated sulfuric acid drying tower 12, a condensing device 13, an absorption tower 14, a desorption tower 15 and a water washing tower 16. Wherein, the neutralization tower 1 is used for removing hydrogen chloride in the tail gas generated in the glyphosate production, and is provided with a hydrolysis tail gas inlet, an alkali liquor inlet, an air outlet and a tower bottom liquid outlet. In one embodiment provided by the utility model, the neutralization tower 1 is a spray tower, and the spray tower is provided with a tower bottom liquid circulating spray pipeline, so that the hydrolysis tail gas can be circularly absorbed by the tower bottom liquid.
In the utility model, the stripping tower 2 is used for stripping and separating the glyphosate acidification synthetic liquid hydrolysis condensate (dilute methanol) generated in the upstream process and the tower bottom liquid discharged from the neutralization tower 1, and is provided with a liquid inlet, a steam inlet, a gas outlet and a wastewater outlet, wherein the liquid inlet of the stripping tower 2 is connected with the tower bottom liquid outlet of the neutralization tower 1, and a connection pipeline thereof is provided with a hydrolysis condensate liquid inlet. In the utility model, the hydrolysis condensate of the glyphosate acidification synthetic solution generated in the upstream process can enter a system through a liquid inlet of the hydrolysis condensate and is mixed with the tower bottom liquid discharged from the neutralization tower 1, so as to realize the pH value adjustment (the pH value is controlled to be 6-14) of the tower bottom liquid of the neutralization tower 1.
In the utility model, the separation tower 3 is used for rectifying and separating the neutralization tail gas discharged from the neutralization tower 1 and the gas-phase product discharged from the stripping tower 2, and is provided with a gas inlet, a tower top discharge hole and a tower bottom liquid outlet, and the gas inlet of the separation tower 3 is respectively connected with a gas outlet of the neutralization tower 1 and a gas outlet of the stripping tower 2.
In the present invention, the methane-removing column 4 is used for rectifying and separating the top gas phase separated by the separation column 3, and recovering the methyl chloride therein. The methane-removing tower 4 is provided with a feed inlet, a tower top discharge port and a tower bottom liquid outlet, and the feed inlet of the methane-removing tower 4 is connected with the tower top discharge port of the separation tower 3.
In the utility model, a concentrated acid absorption tower 5, a concentrated hydrochloric acid absorption tower 6, a dilute hydrochloric acid absorption tower 7 and a water absorption tower 8 are used for removing hydrogen chloride in the tail gas generated in the production of dimethyl phosphite, and are provided with an air inlet, an air outlet, an absorption liquid inlet and a tower bottom liquid outlet. The gas outlet of concentrated hydrochloric acid absorption tower 5 links to each other with the air inlet of concentrated hydrochloric acid absorption tower 6, and the gas outlet of concentrated hydrochloric acid absorption tower 6 links to each other with the air inlet of thin hydrochloric acid absorption tower 7, and the gas outlet of thin hydrochloric acid absorption tower 7 links to each other with the air inlet of water absorption tower 8. In one embodiment provided by the utility model, the concentrated acid absorption tower 5, the concentrated hydrochloric acid absorption tower 6, the dilute hydrochloric acid absorption tower 7 and the water absorption tower 8 are spray towers, the spray towers are provided with tower bottom liquid circulating spray pipelines, so that the tower bottom liquid can circularly absorb the production tail gas, circulating pumps of the four absorption towers are connected through pipelines, the tower bottom liquid can enter the upper-stage absorption tower through the pipeline, the concentrated acid absorption tower 5 is provided with a discharge pipeline behind the circulating pump, and the concentrated acid in the tower bottom is discharged through the corresponding pipeline.
In the utility model, the alkaline tower 9 is used for removing residual hydrogen chloride absorbed by the four-stage absorption tower in the tail gas generated in the dimethyl phosphite production, an air inlet, an air outlet, an alkali liquor inlet and a tower kettle discharge hole are arranged on the alkaline tower 9, and the air inlet of the alkaline tower 9 is connected with the air outlet of the water absorption tower 8. In one embodiment provided by the present invention, the caustic washing tower 9 is a spray tower, and the spray tower is provided with a tower bottom liquid circulating spray pipeline, so that the tower bottom liquid can circularly absorb the production tail gas.
In the utility model, a methyl chloride water scrubber 10 is used for removing methanol in tail gas generated in dimethyl phosphite production, a water inlet, an air outlet, an air inlet and a tower bottom liquid outlet are arranged on the methyl chloride water scrubber 10, and the air inlet of the methyl chloride water scrubber 10 is connected with an air outlet of an alkaline tower 9. In one embodiment provided by the present invention, the methyl chloride washing tower 10 is a spray tower, and the spray tower is provided with a tower bottom liquid circulating spray pipeline, so that the tower bottom liquid can circularly absorb the production tail gas. In one embodiment of the present invention, the methyl chloride water scrubber 10 comprises a plurality of water scrubbers connected in series, and the air outlet of the upper water scrubber is connected to the air inlet of the lower water scrubber.
In the utility model, the methyl chloride alkaline washing tower 11 is used for removing residual methanol and acid gas, and is provided with an air inlet, an air outlet, an alkali liquor inlet and a tower kettle discharge hole, wherein the air inlet of the methyl chloride alkaline washing tower 11 is connected with the air outlet of the methyl chloride water washing tower 10. In one embodiment provided by the utility model, the spray tower is provided with a tower bottom liquid circulating spray pipeline, so that the tower bottom liquid can circularly absorb the production tail gas.
In the present invention, the concentrated sulfuric acid drying tower 12 is used for drying the gaseous crude chloromethane separated from the chloromethane dechlorination tower 4 and the chloromethane alkali washing tower 11 by concentrated sulfuric acid, and is provided with an air inlet, an air outlet, a concentrated sulfuric acid inlet and a tower bottom liquid outlet. In one embodiment provided by the present invention, the concentrated sulfuric acid drying tower 12 is a spray tower, and the spray tower is provided with a tower bottom liquid circulating spray pipeline, so that the tower bottom liquid can circularly dry the gaseous methyl chloride crude product. In an embodiment provided by the present invention, the concentrated sulfuric acid drying tower 12 includes multiple stages of concentrated sulfuric acid drying towers connected in series, and an air outlet of an upper stage of concentrated sulfuric acid drying tower is connected to an air inlet of a lower stage of concentrated sulfuric acid drying tower.
In the present invention, the condensing unit 13 is used for condensing the dry gaseous methyl chloride discharged from the concentrated sulfuric acid drying tower 12 into liquid methyl chloride. The condensing device 13 is provided with an air inlet, a condensate outlet and a non-condensable gas outlet. In one embodiment of the present invention, the condensing unit 13 comprises a plurality of condensers connected in series, and the non-condensable gas outlet of the condenser in the previous stage is connected to the gas port of the condenser in the next stage.
In the utility model, the absorption tower 14 is used for absorbing the chloromethane in the non-condensable gas of the condensing device 13, and is provided with a methanol inlet, a non-condensable gas inlet, an air outlet and a tower bottom liquid outlet.
In the utility model, the desorption tower 15 is used for desorbing methyl chloride in tower bottom liquid of the absorption tower 14, a fresh methanol inlet, a liquid inlet, a gas inlet, a tower bottom liquid outlet and a gas outlet are arranged on the desorption tower 15, and the liquid inlet of the desorption tower 15 is connected with the tower bottom liquid outlet of the absorption tower 14. In one embodiment provided by the present invention, the bottom liquid of the absorption tower 14, which absorbs the methyl chloride, can enter the desorption tower 15 through the liquid inlet; and the tower bottom liquid enters a reboiler through the tower bottom liquid outlet, the tower bottom liquid is heated and vaporized through the reboiler, the gas enters a desorption tower through a gas inlet to bring heat, and the tower bottom liquid of the absorption tower 15 is heated to resolve the chloromethane gas.
In the utility model, the water scrubber 16 is used for removing the methanol in the gas phase at the top of the absorption tower 14, and is provided with an industrial water inlet, a gas outlet and a tower bottom liquid outlet, wherein the gas inlet of the water scrubber 16 is connected with the gas outlet of the absorption tower 14. In one embodiment provided by the present invention, the water scrubber 16 absorbs methanol in the gas phase at the top of the absorption tower 14, and the gas enters the incineration device from the gas outlet at the top of the tower for treatment.
Referring to fig. 2, fig. 2 is a process flow diagram for recovering methyl chloride crude product from glyphosate production tail gas provided by the embodiment of the utility model. Wherein 1 represents a neutralization tower, 2 represents a stripping tower, 2-1 represents a stripping tower first-stage preheater, 2-2 represents a stripping tower second-stage preheater, 2-3 represents a stripping tower third-stage preheater, 2-4 represents a stripping tower cooler, 3 represents a separation tower, 3-1 represents a separation tower condenser, 3-2 represents a separation tower reflux tank, 3-3 represents a low-boiling fan, 3-4 represents a fan post-condenser, 3-5 represents a low-boiling substance intermediate tank, 3-6 represents a separation tower reboiler, 4 represents a methane-removing tower, 4-1 represents a methane-removing tower condenser, 4-2 represents a methane-removing tower reflux tank, 4-3 represents a methane-removing tower reboiler, 4-4 represents a methane-removing buffer tank, and LS represents low-pressure steam.
In one embodiment provided by the present invention, the recovery system further comprises a stripper first-stage preheater 2-1, a stripper second-stage preheater 2-2, and a stripper third-stage preheater 2-3. In the utility model, tower bottom liquid discharged from a neutralization tower 1 is mixed with hydrolysis condensate of glyphosate acidification synthetic liquid, and then is preheated by a first-stage preheater 2-1, a second-stage preheater 2-2 and a third-stage preheater 2-3 of a stripping tower in sequence, and then enters the stripping tower 2 for stripping separation. Wherein, the heat source of the first-stage preheater 2-1 of the stripping tower is preferably a methanol product separated from a low-pressure methanol rectifying tower at the downstream, the heat source of the second-stage preheater 2-2 of the stripping tower is preferably a methanol product separated from a high-pressure methanol rectifying tower at the downstream, and the heat source of the third preheater 2-3 of the stripping tower is preferably steam condensate water.
In one embodiment provided by the utility model, the recovery system further comprises a stripping tower cooler 2-4, and tower bottoms (wastewater) discharged from the stripping tower 2 are cooled by the stripping tower cooler 2-4 and then conveyed to a downstream wastewater treatment device by a pump.
In one embodiment provided by the utility model, the recovery system further comprises a separation tower condenser 3-1, a separation tower reflux tank 3-2, a low-boiling fan 3-3, a fan post-condenser 3-4 and a low-boiling substance intermediate tank 3-5. In the utility model, the gas phase at the top of the separation tower 3 is partially condensed by a separation tower condenser 3-1, the condensate is collected to a separation tower reflux tank 3-2 and then is conveyed by a pump, part of the condensate flows back, and the other part of the condensate enters a chloromethane removal tower 4; the gas phase which is not condensed by the condenser 3-1 of the separation tower is pressurized by a low-boiling fan 3-3 and then is conveyed to a fan rear condenser 3-4, and the condensate is collected to a low-boiling substance intermediate tank 3-5; the gas phase which is not condensed by the blower rear condenser 3-4 is conveyed to the methane-removing tower 4, and the condensate in the low-boiling-point substance intermediate tank 3-5 is also conveyed to the methane-removing tower 4 by a pump.
In an embodiment provided by the present invention, the recycling system further includes a separation tower reboiler 3-6, which is used for heating the bottom liquid of the separation tower 3 to raise the temperature of the bottom liquid for gasification. The heat source of the reboiler 3-6 of the separation column is preferably methanol vapor discharged from the top of a low-pressure methanol rectifying tower at the downstream.
In one embodiment provided herein, the recovery system further includes a demethanizer condenser 4-1 and a demethanizer reflux drum 4-2. In the utility model, the gas at the top of the methane-removing tower 4 is conveyed to a condenser 4-1 of the methane-removing tower through a pipeline for condensation, the condensate generated by condensation is recycled to a reflux tank 4-2 of the methane-removing tower and then refluxed to the methane-removing tower 4; the uncondensed non-condensable gas and the gas phase extracted from the top of the methane dechlorinating tower 4 are conveyed to a concentrated sulfuric acid drying tower 12 as a methyl chloride product.
In one embodiment provided by the utility model, the recovery system further comprises a demethanizer reboiler 4-3, which is used for heating the tower bottom liquid of the demethanizer 4 to heat and gasify the tower bottom liquid. The heat source for the demethanizer reboiler 4-3 is preferably steam condensate.
In an embodiment provided by the present invention, the recycling system further includes a methyl chloride buffer tank 4-4 for buffering gaseous crude methyl chloride discharged from the top of the methyl chloride removal tower 4, a feed inlet of the methyl chloride buffer tank 4-4 is connected to a discharge outlet of the top of the methyl chloride removal tower 4, and a discharge outlet of the methyl chloride buffer tank 4-4 is connected to an air inlet of the concentrated sulfuric acid drying tower 12.
Referring to fig. 3 and 4, fig. 3 is a process flow diagram of a first half section of a process for recovering a crude methyl chloride product from a tail gas generated in the production of dimethyl phosphite according to an embodiment of the present invention, and fig. 4 is a process flow diagram of a second half section of the process for recovering a crude methyl chloride product from a tail gas generated in the production of dimethyl phosphite according to an embodiment of the present invention. Wherein 5 represents a concentrated acid absorption tower, 6 represents a concentrated hydrochloric acid absorption tower, 7 represents a dilute hydrochloric acid absorption tower, 8 represents a water absorption tower, 9 represents an alkaline washing tower, 9-1 represents a cooler before a vacuum pump, 9-2 represents a buffer tank before the vacuum pump, 9-3 represents a vacuum pump set, 9-4 represents a vacuum rear buffer tank, 10-1 represents a condenser before the water washing tower, 10-2 represents a primary methyl chloride water washing tower, 10-3 represents a secondary methyl chloride water washing tower, 10-4 represents a tertiary methyl chloride water washing tower, 10-5 represents a quaternary methyl chloride water washing tower, 11 represents a methyl chloride alkaline washing tower, 11-1 represents a fan buffer tank before a gas holder, and 11-2 represents a gas holder.
In one embodiment provided by the utility model, the system for recovering the methyl chloride crude product from the dimethyl phosphite further comprises a cooler 9-1 before the vacuum pump, a buffer tank 9-2 before the vacuum pump, a vacuum pump group 9-3 and a buffer tank 9-4 after the vacuum pump. In the utility model, a vacuum pump set 9-3 pulls tail gas produced by dimethyl phosphite to sequentially pass through a concentrated acid absorption tower 5, a concentrated hydrochloric acid absorption tower 6, a dilute hydrochloric acid absorption tower 7, a water absorption tower 8 and an alkaline washing tower 9 to remove hydrogen chloride in the tail gas, then the water content of the tail gas is reduced through a vacuum pump front cooler 9-1, the tail gas is buffered in a vacuum pump front buffer tank 9-2 and then enters a vacuum pump set 9-3, the tail gas is conveyed to a vacuum rear buffer tank 9-4 through the vacuum pump set to be buffered, and then the tail gas enters a water washing system.
In one embodiment provided by the utility model, the system for recovering the crude methyl chloride from the dimethyl phosphite further comprises a condenser 10-1 before the water washing tower, and the water in the tail gas is removed again.
In an embodiment provided by the present invention, the methyl chloride washing tower 10 in the system for recovering a crude methyl chloride product from dimethyl phosphite specifically comprises a first-level methyl chloride washing tower 10-2, a second-level methyl chloride washing tower 10-3, a third-level methyl chloride washing tower 10-4, and a fourth-level methyl chloride washing tower 10-5, which are connected in series, wherein an air outlet of the first-level methyl chloride washing tower 10-2 is connected with an air inlet of the second-level methyl chloride washing tower 10-3, an air outlet of the second-level methyl chloride washing tower 10-3 is connected with an air inlet of the third-level methyl chloride washing tower 10-4, and an air outlet of the third-level methyl chloride washing tower 10-4 is connected with an air inlet of the fourth-level methyl chloride washing tower 10-5. In the utility model, gas from a condenser in front of a water washing tower sequentially passes through a first-stage methyl chloride water washing tower 10-2, a second-stage methyl chloride water washing tower 10-3, a third-stage methyl chloride water washing tower 10-4 and a fourth-stage methyl chloride water washing tower 10-5 to remove methanol in the gas, the tower kettles of the four methyl chloride water washing towers are communicated through pipelines, and water in the tower kettle can enter the tower kettle of the upper-stage methyl chloride water washing tower through the pipelines.
In an embodiment provided by the present invention, the system for recovering the crude methyl chloride product from dimethyl phosphite further comprises a buffer tank 11-1 of a front gas holder blower, which is used for reducing the non-uniformity of the flow rate of the crude methyl chloride product in a gas phase from the methyl chloride caustic tower 11 and improving the suction performance of the front gas holder blower, wherein the gas inlet of the front gas holder blower is connected with the gas outlet of the methyl chloride caustic tower 11, and the gas outlet of the front gas holder blower is connected with the gas inlet of the front gas holder blower.
In one embodiment provided by the utility model, the system for recovering the crude methyl chloride from the dimethyl phosphite further comprises a gas holder 11-2. And the gas-phase methyl chloride crude product coming out of the gas outlet of the methyl chloride alkaline washing tower 11 is sent to a gas holder 11-2 for caching through a gas holder front fan.
Referring to fig. 5, fig. 5 is a flow chart of a crude chloromethane refining process provided in the embodiment of the utility model. Wherein 12-1 represents a cooler in front of a drying tower, 12-2 represents a first-stage concentrated sulfuric acid drying tower, 12-3 represents a second-stage concentrated sulfuric acid drying tower, 12-4 represents a third-stage concentrated sulfuric acid drying tower, 12-5 represents a fourth-stage concentrated sulfuric acid drying tower, 12-6 represents a concentrated sulfuric acid drying tower rear demister, 12-7 represents a dry methyl chloride buffer tank, 13-1 represents a methyl chloride compressor, 13-2 represents a first-stage condenser, 13-3 represents a second-stage condenser, 13-4 represents a third-stage condenser, 13-5 represents a condensing device rear demister, and 13-6 represents a methyl chloride condensate tank.
In one embodiment of the present invention, the refining of the crude methyl chloride further comprises a pre-drying tower cooler 12-1. The gaseous chloromethane crude product is precooled and enters a concentrated sulfuric acid drying tower 12.
In an embodiment provided by the present invention, the concentrated sulfuric acid drying tower 12 in the recovery system specifically includes a first concentrated sulfuric acid drying tower 12-2, a second concentrated sulfuric acid drying tower 12-3, a third concentrated sulfuric acid drying tower 12-4 and a fourth concentrated sulfuric acid drying tower 12-5 which are serially connected, an air outlet of the first concentrated sulfuric acid drying tower 12-2 is connected to an air inlet of the second concentrated sulfuric acid drying tower 12-3, an air outlet of the second concentrated sulfuric acid drying tower 12-3 is connected to an air inlet of the third concentrated sulfuric acid drying tower 12-4, and an air outlet of the third concentrated sulfuric acid drying tower 12-4 is connected to an air inlet of the fourth concentrated sulfuric acid drying tower 12-5. In the utility model, gaseous chloromethane crude products from a dechlorination methane tower 4 and a chloromethane alkali washing tower 11 are sequentially subjected to concentrated sulfuric acid drying treatment in a first-stage concentrated sulfuric acid drying tower 12-2, a second-stage concentrated sulfuric acid drying tower 12-3, a third-stage concentrated sulfuric acid drying tower 12-4 and a fourth-stage concentrated sulfuric acid drying tower 12-5, tower kettles of the four concentrated sulfuric acid drying towers are communicated through pipelines, and concentrated sulfuric acid in the tower kettle can enter a tower kettle of a previous-stage concentrated sulfuric acid drying tower through the pipelines.
In one embodiment of the present invention, the recovery system further comprises a concentrated sulfuric acid drying tower rear demister 12-6 and a dry methyl chloride buffer tank 12-7. In the utility model, dry gaseous methyl chloride discharged from a concentrated sulfuric acid drying tower 12 passes through a concentrated sulfuric acid drying tower rear demister 12-6 for defoaming and then enters a dry methyl chloride buffer tank 12-7, liquid phases collected in the concentrated sulfuric acid drying tower rear demister 12-6 and the dry methyl chloride buffer tank 12-7 return to the concentrated sulfuric acid drying tower 12, and a gas phase (dry gaseous methyl chloride) in the dry methyl chloride buffer tank 12-7 enters a condensation process. In the utility model, the operation temperature of the demister 12-6 behind the concentrated sulfuric acid drying tower is preferably controlled to be less than or equal to-5 ℃.
In one embodiment of the present invention, the recycling system further comprises a methyl chloride compressor 13-1, and gaseous methyl chloride to be introduced into the condensing unit 13 is first compressed in the methyl chloride compressor 13-1 and then condensed in the condensing unit 13.
In an embodiment provided by the present invention, the condensing device 13 in the recovery system specifically includes a first-stage condenser 13-2, a second-stage condenser 13-3, and a third-stage condenser 13-4, which are arranged in series, wherein a non-condensable gas outlet of the first-stage condenser 13-2 is connected to an air inlet of the second-stage condenser 13-3, and a non-condensable gas outlet of the second-stage condenser 13-3 is connected to an air inlet of the third-stage condenser 13-4. In the utility model, dry gaseous methyl chloride from a concentrated sulfuric acid drying tower 12 or a methyl chloride compressor 13-1 enters a first-stage condenser 13-2 for condensation, uncondensed noncondensable gas enters a second-stage condenser 13-3 for continuous condensation, uncondensed noncondensable gas enters a third-stage condenser 13-4 for continuous condensation, and condensate obtained by condensation of each stage of condenser is the liquid methyl chloride product recovered by the utility model.
In one embodiment provided by the utility model, the recovery system further comprises a condensation device rear demister 13-5 for defoaming the non-condensable gas discharged from the condensation device 13, and the liquid phase generated in the condensation device 13 is conveyed to a methyl chloride condensate tank 13-6 through a pipeline. In the present invention, the operation temperature of the demister 13-5 after the condensing unit is preferably controlled to-5 ℃.
In one embodiment of the present invention, the recycling system further comprises a methyl chloride condensate tank 13-6 for collecting condensate (liquid methyl chloride) generated by the condensing unit 13.
Referring to fig. 6, fig. 6 is a process flow diagram of a methyl chloride deep recovery system provided by the embodiment of the utility model. Wherein 14 denotes an absorption column, 15 denotes a desorption column, 15-1 denotes a reboiler, 15-2 denotes a methanol cooler, 15-3 denotes a methanol condenser, and 16 denotes a water washing column.
In an embodiment provided by the present invention, the methyl chloride deep recovery system further includes a reboiler 15-1, which is used for heating the bottom liquid of the desorption tower 15 to raise the temperature of the bottom liquid and gasify the bottom liquid.
In one embodiment provided by the utility model, the methyl chloride deep recovery system further comprises a methanol cooler 15-2 and a methanol condenser 15-3, which are used for cooling the methanol from the bottom of the desorption tower 15 so that the methanol can absorb more methyl chloride.
For the sake of clarity, taking the methyl chloride cleaning and recycling system described in fig. 2, fig. 3, fig. 4, fig. 5 and fig. 6 as an example, the specific operation process of the recycling system is as follows:
hydrolysis tail gas generated in the production process of glyphosate is conveyed to a neutralization tower 1 through a pipeline, the hydrolysis tail gas and fresh liquid caustic soda and circulating alkali liquor are subjected to gas-liquid neutralization reaction in the tower, a gas phase at the top of the tower is conveyed to a separation tower 3 through a pipeline, and tower bottoms are conveyed to a stripping tower 2.
Mixing tower bottom liquid from a neutralization tower 1 and hydrolyzed condensate of glyphosate acidized synthetic liquid, conveying the mixture to a first-stage preheater 2-1 of a stripping tower by a pump, preheating the mixture by hot methanol, conveying the mixture to a second-stage preheater 2-2 of the stripping tower by a pipeline, preheating the mixture by the hot methanol, conveying the mixture to a third-stage preheater 2-3 of the stripping tower by the pipeline, preheating the mixture by steam condensate water, and conveying the mixture to the stripping tower 2 by the pipeline. Low-pressure steam (LS) is introduced into a tower kettle of the stripping tower 2 to strip materials in the tower, a gas phase at the top of the tower is conveyed to the separation tower 3 by a pipeline, and waste water at the bottom of the tower is conveyed to a downstream waste water treatment device by a pump after being cooled by a stripper cooler 2-4.
The gas phases from the neutralization tower 1 and the stripping tower 2 are separated in a separation tower 3, the gas phase at the top of the tower is partially condensed by a separation tower condenser 3-1, the condensate is collected in a separation tower reflux tank 3-2 and then is conveyed by a pump, part of the condensate flows back, and the other part of the condensate flows into a chloromethane removal tower 4; and (3) after the uncondensed gas phase enters a low-boiling fan 3-3 to be pressurized, conveying the gas phase to a fan rear condenser 3-4 by using a pipeline, collecting the condensate to a low-boiling substance intermediate tank 3-5, conveying the gas phase to a methane dechlorinating tower 4 by using a pipeline, and conveying the collected condensate in the low-boiling substance intermediate tank 3-5 to the methane dechlorinating tower 4 by using a pump. The diluted methanol in the tower bottom of the separation tower 3 is heated by methanol steam in a reboiler 3-6 of the separation tower and then is conveyed to a low-pressure methanol rectifying tower at the downstream by a pump.
Non-condensable gas and low-boiling-point substances from a separation tower 3 are rectified in a methane-removing column 4, partial gas at the top of the column is conveyed to a condenser 4-1 of the methane-removing column, condensate is recycled to a reflux tank 4-2 of the methane-removing column, and the non-condensable gas and gas phase extracted from the top of the column are conveyed to a methane chloride buffer tank 4-4 together by a pipeline as a crude product of methane chloride; and the condensate collected by the reflux tank 4-2 of the methane-removing tower flows back to the methane-removing tower 4. And heating the tower bottom liquid in a dechlorination methane tower reboiler 4-3 by using steam condensate water, and conveying the tower bottom liquid to a downstream methylal rectifying tower by using a pump. And conveying the crude chloromethane from the top of the chloromethane dechlorinating tower 4 to a chloromethane buffer tank 5-1 for buffering through a pipeline.
Tail gas from the production process of dimethyl phosphite is conveyed to a concentrated acid absorption tower 5 through a pipeline, hydrogen chloride gas in the tower is absorbed by mixed liquid of tower bottom liquid of the concentrated acid absorption tower and tower bottom liquid of a concentrated hydrochloric acid absorption tower, gas phase at the tower top is conveyed to a concentrated hydrochloric acid absorption tower 6, part of the tower bottom liquid is conveyed out as finished hydrochloric acid, and the other part of the tower bottom liquid is used as circulating absorption liquid.
The gas phase at the top of the tower from the concentrated hydrochloric acid absorption tower 5 enters a concentrated hydrochloric acid absorption tower 6, the hydrogen chloride gas in the tower is absorbed by the mixed solution of the tower bottom liquid of the concentrated hydrochloric acid absorption tower and the tower bottom liquid of the dilute hydrochloric acid absorption tower, the gas phase at the top of the tower is conveyed to a concentrated hydrochloric acid absorption tower 7, part of the tower bottom liquid is used as absorption liquid to be supplemented to the concentrated hydrochloric acid absorption tower 5, and the rest is used as circulating absorption liquid of the concentrated hydrochloric acid absorption tower.
The gas phase at the top of the tower from the concentrated hydrochloric acid absorption tower 6 enters a dilute hydrochloric acid absorption tower 7, the hydrogen chloride gas in the tower is absorbed by the mixed liquid of the tower bottom liquid of the dilute hydrochloric acid absorption tower and the tower bottom liquid of the water absorption tower, the gas phase at the top of the tower is conveyed to a water absorption tower 8, a part of the tower bottom liquid is used as absorption liquid to be supplemented to the concentrated hydrochloric acid absorption tower 6, and the rest is used as circulating absorption liquid of the dilute hydrochloric acid absorption tower.
The gas phase at the top of the tower from the dilute hydrochloric acid absorption tower 7 enters a water absorption tower 8, the hydrogen chloride gas in the tower is absorbed by the mixed liquid of tower bottom liquid of the water absorption tower and water, the gas phase at the top of the tower is conveyed to an alkaline washing tower 9, a part of the tower bottom liquid is used as absorption liquid to be supplemented to the dilute hydrochloric acid absorption tower 7, and the rest is used as circulating absorption liquid of the water absorption tower.
The gas phase at the top of the tower from the water absorption tower 8 is removed with liquid caustic soda in an alkaline washing tower 9, the gas phase at the top of the alkaline washing tower 9 is conveyed to a methyl chloride water washing tower 10, and the tower bottom liquid is circulated to the top of the tower as absorption liquid.
The gas phase from the alkaline tower 9 enters a condenser 10-1 in front of a methyl chloride water scrubber through a pipeline, water in the gas phase is removed by condensation, then methanol in the gas phase is removed by water washing in a first-level methyl chloride water scrubber 10-2, a second-level methyl chloride water scrubber 10-3, a third-level methyl chloride water scrubber 10-4 and a fourth-level methyl chloride water scrubber 10-5, and finally the gas phase enters a methyl chloride alkaline scrubber 11 to remove residual acid gas to obtain a gaseous methyl chloride crude product. And conveying the gaseous chloromethane crude product to a gas holder 11-2 for caching through a gas holder front fan.
The crude chloromethane from the buffer tank 4-4 and the gas holder 11-2 enters a front cooler 12-1 of a concentrated sulfuric acid drying tower through pipelines to be cooled and then enters a first-stage concentrated sulfuric acid drying tower 12-2, the chloromethane in the tower is subjected to concentrated sulfuric acid pickling and then is conveyed to a second-stage concentrated sulfuric acid drying tower 12-3 through a pipeline, and then sequentially passes through a third-stage concentrated sulfuric acid drying tower 12-4 and a fourth-stage concentrated sulfuric acid drying tower 12-5 and then enters a concentrated sulfuric acid drying tower and a foam remover 12-6; the gas phase in the demister 12-6 after the concentrated sulfuric acid drying tower enters a dry methyl chloride buffer tank 12-7, and the liquid phase returns to a four-stage concentrated sulfuric acid drying tower 12-5; the liquid phase in the dry methyl chloride buffer tank 12-7 returns to the four-stage concentrated sulfuric acid drying tower 12-5, and the gas phase enters a methyl chloride compressor 13-1.
The dry gaseous chloromethane from the dry chloromethane buffer tank 12-7 is subjected to heat exchange and then compressed in a chloromethane compressor 13-1, compressed gas is subjected to water cooling in a primary condenser 13-2, condensate is conveyed to a chloromethane condensate tank 13-6, and non-condensable gas enters a secondary condenser 13-3; the non-condensable gas is subjected to salt cooling in a secondary condenser 13-3, the condensate is conveyed into a chloromethane condensate tank 13-6, and the non-condensable gas enters a tertiary condenser 13-4; the non-condensable gas is subjected to deep cooling in a three-stage condenser 13-4, the condensate is conveyed into a chloromethane condensate tank 13-6, and the non-condensable gas enters a condenser and then a demister 13-5; the non-condensable gas is defoamed in a demister 13-5 behind the condensing device, the generated liquid phase is sent to a methyl chloride condensate tank 13-6, and the gas is sent to an absorption tower 14.
The gas from the demister 13-5 enters an absorption tower 14 from the tower bottom, the methanol enters the absorption tower from the tower top through a water-cooled cooler 15-3 and a salt-cooled cooler 15-2, the methyl chloride is sprayed and absorbed, the gas phase at the tower top is conveyed to a water washing tower 16 through a pipeline, and the tower bottom liquid is conveyed to a desorption tower 15.
Tower bottom liquid from the absorption tower 14 enters a desorption tower 15 from the top of the tower, methyl chloride gas in the tower is desorbed by heating through a reboiler 15-1 connected with the tower bottom, the methyl chloride gas is condensed by a condenser connected with the top of the tower to obtain methanol, the methyl chloride gas enters a methyl chloride crude product refining system again for recovery, and the tower bottom liquid is conveyed to the absorption tower 14 through a pump to absorb methyl chloride; the condenser at the top of the tower utilizes frozen brine to condense methanol; the reboiler connected with the tower kettle heats the tower kettle liquid by using the steam condensate water.
The gas phase at the top of the tower from the absorption tower 14 is in a water washing tower 16, industrial water is sprayed from the top of the tower to absorb methanol, so that the gas phase at the top of the tower and tower bottom liquid are obtained, the gas phase at the top of the tower is conveyed to an incineration device through a pipeline to be incinerated, and the tower bottom liquid is conveyed to an environmental protection station to be treated.
The recovery system provided by the utility model can be used for neutralizing, stripping, multi-effect rectifying and deeply recovering the glyphosate production tail gas, so that the quality and recovery rate of the recovered chloromethane crude product are improved, and the recovery system has good economic and environmental benefits. Specifically, the recovery system and the recovery process provided by the utility model have at least the following advantages:
1) the recovery rate of the chloromethane is improved;
2) the content of water, methanol and methylal in the crude chloromethane obtained by recovering the tail gas in glyphosate production is greatly reduced, the rectified crude chloromethane gas does not contain other components except chloromethane, dimethyl ether and air basically, the quality of the crude chloromethane recovered by glyphosate is improved, the problem of higher sulfuric acid consumption in the subsequent sulfuric acid drying of the crude chloromethane caused by mixing low-boiling-point substances such as methanol and methylal into the chloromethane gas can be avoided, and the usage amount of sulfuric acid in the downstream sulfuric acid drying process and the treatment amount of waste sulfuric acid can be reduced by more than 55 percent;
3) the chloromethane crude product obtained by recovering the glyphosate production tail gas does not need water washing and alkali washing processes during subsequent treatment, so that the waste water amount can be reduced, the equipment and electric instrument investment of the corresponding process can be reduced, and the investment cost can be reduced;
4) when the methyl chloride is recovered from the tail gas generated in the dimethyl phosphite production, the hydrogen chloride in the tail gas is also recovered and utilized, so that the cost is further reduced;
5) deep recovery is carried out on the refined tail gas of the crude chloromethane product, so that the recovery rate of the chloromethane is further improved, and the resource utilization rate is improved; and in the tail gas burning process, the influence of the chloromethane on the burning device is reduced, and the tail gas burning device is safer.
Claims (8)
1. The utility model provides a degree of depth recovery system of methyl chloride, characterized by, including retrieving methyl chloride crude device, methyl chloride crude refining plant, methyl chloride degree of depth recovery unit, retrieve methyl chloride crude device including dechlorination methane tower, methyl chloride crude refining plant includes: the concentrated sulfuric acid drying tower is connected with a discharge port at the top of the methane-removing tower and a gas outlet of a chloromethane alkali washing tower; the condensing device is connected with the gas outlet of the concentrated sulfuric acid drying tower; the methyl chloride degree of depth recovery unit includes: the absorption tower is connected with a non-condensable gas outlet of the condensing device; the desorption tower is connected with the tower liquid outlet of the absorption tower; and the water washing tower is connected with the top air outlet of the absorption tower.
2. The deep recovery system of methyl chloride as claimed in claim 1, wherein the device for recovering crude methyl chloride comprises a device for recovering crude methyl chloride from tail gas generated in glyphosate production and a device for recovering crude methyl chloride from tail gas generated in dimethyl phosphite production.
3. The deep recovery system of methyl chloride as set forth in claim 2, wherein the device for recovering crude methyl chloride from the tail gas of glyphosate production comprises: a neutralization tower; the stripper is connected with the tower bottom liquid outlet of the neutralization tower, and a hydrolysis condensate liquid inlet is formed in a connecting pipeline between the tower bottom liquid outlet of the neutralization tower and the stripper; the separation tower is respectively connected with the gas outlet of the neutralization tower and the gas outlet of the stripping tower; and the methane-removing tower is connected with a discharge hole at the top of the separation tower.
4. The deep recovery system of methyl chloride as set forth in claim 2, wherein the crude methyl chloride product recovery device from the tail gas from dimethyl phosphite production comprises: a concentrated acid absorption tower; the concentrated hydrochloric acid absorption tower is connected with an air outlet at the top of the concentrated acid absorption tower; the dilute hydrochloric acid absorption tower is connected with a gas outlet at the top of the concentrated hydrochloric acid absorption tower; the water absorption tower is connected with a gas outlet at the top of the dilute hydrochloric acid absorption tower; the alkaline washing tower is connected with an air outlet of the water absorption tower; a chloromethane water scrubber connected with the top gas outlet of the alkaline tower; and the methyl chloride alkaline washing tower is connected with an air outlet of the methyl chloride water washing tower.
5. The deep recovery system of methyl chloride as claimed in claim 4, wherein the methyl chloride washing tower comprises multiple stages of methyl chloride washing towers which are connected in series, and the gas outlet of the upper stage of methyl chloride washing tower is connected with the gas inlet of the lower stage of methyl chloride washing tower.
6. The deep recovery system of methyl chloride, according to any one of claims 1 to 4, wherein the concentrated sulfuric acid drying tower comprises a plurality of stages of concentrated sulfuric acid drying towers arranged in series, and the gas outlet of the previous stage of concentrated sulfuric acid drying tower is connected with the gas inlet of the next stage of concentrated sulfuric acid drying tower.
7. The deep recovery system of methyl chloride as claimed in claim 3, further comprising a methyl chloride buffer tank disposed between the top discharge port of the de-chloromethane tower and the concentrated sulfuric acid drying tower, wherein the feed inlet of the methyl chloride buffer tank is connected with the top discharge port of the de-chloromethane tower, and the discharge port of the methyl chloride buffer tank is connected with the air inlet of the concentrated sulfuric acid drying tower.
8. The deep recovery system of methyl chloride as claimed in claim 4, further comprising a methyl chloride gas cabinet disposed between the top discharge port of the methyl chloride alkaline tower and the concentrated sulfuric acid drying tower, wherein the feed port of the methyl chloride gas cabinet is connected with the top discharge port of the dechlorination methane tower, and the discharge port of the methyl chloride gas cabinet is connected with the gas inlet of the concentrated sulfuric acid drying tower.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121805803.6U CN216427170U (en) | 2021-08-04 | 2021-08-04 | Deep recovery system for chloromethane |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121805803.6U CN216427170U (en) | 2021-08-04 | 2021-08-04 | Deep recovery system for chloromethane |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN216427170U true CN216427170U (en) | 2022-05-03 |
Family
ID=81314827
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202121805803.6U Active CN216427170U (en) | 2021-08-04 | 2021-08-04 | Deep recovery system for chloromethane |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN216427170U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115501723A (en) * | 2022-09-29 | 2022-12-23 | 山东海科创新研究院有限公司 | Method for recovering methane chloride waste gas |
-
2021
- 2021-08-04 CN CN202121805803.6U patent/CN216427170U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115501723A (en) * | 2022-09-29 | 2022-12-23 | 山东海科创新研究院有限公司 | Method for recovering methane chloride waste gas |
| CN115501723B (en) * | 2022-09-29 | 2023-11-03 | 山东海科创新研究院有限公司 | Method for recycling methane chloride waste gas |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104311383B (en) | A kind of method of the hydrogen chloride production monochloro methane that utilizes by-product in tetrachloro-ethylene production process | |
| CN110698320B (en) | Continuous recovery device and continuous recovery process for glyphosate hydrolyzed gas phase | |
| CN1199921C (en) | Technique for cleanly recovering byproduct methyl chloride of glyphosate acid | |
| CN212864613U (en) | Synthetic leather waste water treatment and DMF recovery system | |
| CN103589462A (en) | Technological method for purifying coal oven gas and recovering chemical products | |
| CN107438475A (en) | The method of Energy Efficient recovery carbon dioxide and the equipment suitable for running this method from absorbent | |
| CN216427170U (en) | Deep recovery system for chloromethane | |
| CN108409532B (en) | System and process for recycling solvent for producing glyphosate by alkyl ester method based on secondary condensation | |
| CN108380029A (en) | A kind of alkyl esterification method glyphosate solvent recovering system and technique | |
| CN105647583B (en) | Novel absorption stabilizing process and system | |
| CN100491245C (en) | Method for preparing liquid carbon dioxide in foodstuff level by using tail gas of cement kiln | |
| CN110342717A (en) | Gasification energy couples ammonia recovery system and method | |
| CN103657136A (en) | Method and equipment for evaporative crystallization of aluminium chloride | |
| CN216427171U (en) | Clean recovery system of methyl chloride in glyphosate and dimethyl phosphite production tail gas | |
| CN1289448C (en) | Clean reclaiming process for byproduct chloromethane of glyphosate acid | |
| CN205528524U (en) | Utilize phenol sodium salt to prepare device of crude carbolic acid | |
| CN211753891U (en) | Recovery system of tail gas is hydrolysised to glyphosate synthetic liquid | |
| CN108083984A (en) | For glyphosate solvent and the method for by-product recovery | |
| CN111393257A (en) | Method for recovering chloroethane from chloroethane-containing waste gas in production of ethyl maltol and homologues thereof | |
| CN108358763B (en) | Alkyl ester method glyphosate solvent recovery system and process based on three-stage condensation | |
| CN101544530B (en) | Method for deep removal of water in ethyne and chlorine hydride mixed gas | |
| CN106744720B (en) | The circulation recycling system and its operation process of trichloroacetaldehyde by-product dilute sulfuric acid | |
| CN111170826A (en) | Clean recovery system and clean recovery process for chloromethane in glyphosate production tail gas | |
| CN215312268U (en) | High-efficient dilute hydrochloric acid deep analysis's optimizing apparatus | |
| CN211921377U (en) | Clean recovery system of methyl chloride in glyphosate production tail gas |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |