CN1328992A - Aminomethane separation method - Google Patents
Aminomethane separation method Download PDFInfo
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- CN1328992A CN1328992A CN 00116535 CN00116535A CN1328992A CN 1328992 A CN1328992 A CN 1328992A CN 00116535 CN00116535 CN 00116535 CN 00116535 A CN00116535 A CN 00116535A CN 1328992 A CN1328992 A CN 1328992A
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Abstract
The present invention relates to a separation method of methylamine, and it characterized by adopting four-tower process of deamination tower, extraction tower, dehydration tower and separation tower. The residue of dehydration tomor is passed through the reboiler of separation tower and heat-exchanged, then a part of material can be circulated, and used as a part of extraction agent, and the residue of separation tower can be circulated, and fed into the dehydration tower, so that the said invention can utilize the same flow path to obtain three kinds of products of monomethylamine, dimethylamine and trimethylamine simultaneously. It features less dosage of fresh water, less waste water and low energy consumption, and can be used in industrial production.
Description
The present invention relates to aminomethane separation method.
Methylamine is the raw material of medicine, agricultural chemicals, solvent, dyestuff, resin, rubber and explosive, also can be used as colour additive, catalyzer, stopper and oxidation inhibitor, and purposes is very extensive.
Industrial normally in the presence of the silica-alumina catalyst of aluminum oxide, silicon oxide one aluminum oxide and so on, methyl alcohol and ammonia successive reaction are made methylamine.Reaction generally is in high pressure and 300～500 ℃ of temperature ranges, carries out in gas phase.Reaction product Monomethylamine, dimethylamine and Trimethylamine 99 distribute and form near thermodynamic(al)equilibrium, and Trimethylamine 99 content is the highest, and Monomethylamine and dimethylamine are lower, and this class catalyzer is commonly referred to as equilibrium catalyst.Because dimethylamine is at the industrial chemical intermediate that is widely used as, therefore, the main purpose product of methyl alcohol or dme amination reaction is a dimethylamine.For improving dimethylamine output, reducing Monomethylamine and Trimethylamine 99 output, industrial common employing circulates unnecessary Monomethylamine and Trimethylamine 99, adjust the catalyzer of raw material nitrogen/carbon ratio and application enhancements.
The eighties mid-term, the industrial appearance uses zeolite catalyst to produce the method for methylamine.Methyl alcohol and ammonia are made methylamine by the zeolite catalyst of mordenite and so on, reaction product Monomethylamine, dimethylamine, Trimethylamine 99 are formed distribution away from thermodynamic equilibrium value, can generate dimethylamine by highly selective, greatly reduce the generation of Trimethylamine 99, this type of catalyzer is called the unbalanced type catalyzer.But the greatest drawback that this type of unbalanced type catalyzer exists is that Trimethylamine 99 can not be transformed into dimethylamine by circulation, can only go to be separated to subsequent processing, uses as the purpose product.In a sense, this method has limited the total turnout of dimethylamine greatly, and relevant technology in this respect has more document to mention.
No matter be to produce methylamine with equilibrium catalyst, still produce methylamine with the unbalanced type catalyzer, its reaction product is the mixture that contains ammonia, mixes methylamine, first alcohol and water, must adopt a kind of separation and purification technology that this mixture is separated, just can obtain pure Monomethylamine, dimethylamine and Trimethylamine 99 product, reclaim unreacted ammonia and methyl alcohol simultaneously and it is looped back the amination reaction device, to reduce consumption of raw materials.The technology of relevant methylamine separating and refining process aspect has more document to mention.In following paragraph, summarize relevant with the field of the invention representative document.
Aminomethane separation method early is to adopt azeotropic distillation technology.This technology has been extracted distil process at present and has replaced because energy consumption is big and can not get the Trimethylamine 99 product.
In U.S. Pat 2998355, methylamine mixture is earlier through an extraction tower, water with part dehydration tower still is made extraction agent, extract the Trimethylamine 99 product from cat head, tower bottoms through with dehydration tower bottoms heat exchange after, enter dehydration tower, steam Monomethylamine, dimethylamine and a spot of ammonia of vapor phase ammonia (looping back synthesis reactor) and liquid phase from the dehydration cat head.This mixture enters knockout tower, isolates Monomethylamine and ammonia from cat head, and tower bottoms then arrives treating tower; Isolate the dimethylamine product from refining cat head, tower bottoms is portion water and unreacted methanol.This flow process can't obtain three kinds of methylamine products simultaneously to produce the dimethylamine product.
The clear 51-68506 of Japanese Patent JP has described the separation method of methylamine mixture.In this patent, Monomethylamine (MMA), Trimethylamine 99 (TMA) and NH
3Steam from the first azeotropic cat head with the azeotrope form, enter the second azeotropic tower.Steam MMA, TMA and NH from the second azeotropic cat head
3Azeotrope loops back synthesis reactor, is pure MMA product (99.9%) at the bottom of the tower.The logistics of coming out at the bottom of first tower enters the 3rd tower, and to steam purity from cat head be 99.8% TMA, and DMA of tower still (dimethylamine) and water enter last rectifying tower, and steam the DMA product from cat head.The steam of this separation process consumption can reduce more than 18% than four traditional column distillations.
In the clear 57-108041 of another piece Japanese Patent JP, the amination reaction mixture carries out component distillation, the azeotrope of cat head (about 82.3%NH through deammoniation tower earlier
3, 16.46%TMA and 1.23%MMA) phlegma is as the heat-eliminating medium of dehydration tower condenser, the logistics of tower still enters extraction tower.The TMA of extraction cat head is as the heating medium of MMA and DMA knockout tower reboiler.This separation process can reduce the consumption of steam and water coolant.
Full scale plant adopts methylamine separating and refining technical process shown in Figure 2 usually at present: contain Monomethylamine, dimethylamine, Trimethylamine 99, ammonia, methyl alcohol, water and a spot of heavy component 1, liquid phase enters deammoniation tower 2 middle parts, ammonia and part Trimethylamine 99 steam from cat head with the form of azeotrope, reflux in the condensation rear section; Another part logistics 3 loops back reactor.Deammoniation tower 2 tower still logistics 4 directly enter the middle part of extraction tower 5, and extraction tower utilizes the principle of extracting rectifying, is extraction agent with water 12, after interchanger 16 heat exchange, extracts Trimethylamine 99 product 6 from logistics 4.Extraction tower 5 tower still logistics 7 usefulness pumps are squeezed into the middle part of dehydration tower 8, and Monomethylamine and dimethylamine steam from cat head, reflux in the condensation rear section, and part logistics 9 enters knockout tower 13, and 11 of water, methyl alcohol and a spot of heavy components flow out from the tower still, go methanol distillation column to reclaim methyl alcohol.In knockout tower 13, Monomethylamine product 14 steams from cat head, and dimethylamine is extracted out from knockout tower bottom side line gas phase or liquid phase, after condensation, part is returned knockout tower 13, and part is separated tower bottoms 17 and followed back the material of deammoniation tower 2 middle parts as raw material 1 as product dimethylamine 15.But this technical process exists fresh extraction water consumption big, and energy consumption is big, the shortcoming that waste water is many.
The objective of the invention is that Monomethylamine in the conventional art, dimethylamine and Trimethylamine 99 product can not obtain in same flow process simultaneously or to produce waste water many in order to overcome, the fresh water consumption is big, and the shortcoming that energy consumption is high provides a kind of new aminomethane separation method.This method have in same flow process, can obtain Monomethylamine, dimethylamine and three kinds of products of Trimethylamine 99 simultaneously and have a fresh water consumption little, characteristic of low energy consumption.
The objective of the invention is to realize by following technical scheme: a kind of aminomethane separation method in turn includes the following steps:
A) contain the raw material of ammonia, Monomethylamine, dimethylamine, Trimethylamine 99, first alcohol and water, liquid phase enters the deammoniation tower middle part, and ammonia and part Trimethylamine 99 steam from the deammoniation tower cat head with the azeotrope form, reflux through the condensation rear section, and another part loops back reactor;
B) logistics of deamination Tata still enters the extraction tower middle part, and extraction agent enters from extraction tower top, extracts Trimethylamine 99 at the extraction tower top, and extraction agent is made up of fresh water and partial dehydration tower bottoms;
C) logistics of extraction tower still and from the knockout tower still logistics converges the back as dehydration tower middle part feed material, Monomethylamine and dimethylamine steam from dehydration column overhead, a part passes back into dehydration tower, a part is as knockout tower middle part feed material, a part is as extraction agent after the knockout tower reboiler reclaims heat for the logistics of dehydration tower still, and another part goes methanol distillation column to reclaim methyl alcohol;
D) enter the material of knockout tower, after knockout tower separated, Monomethylamine steamed from the knockout tower cat head, and dimethylamine is extracted out from knockout tower bottom side line gas phase or liquid phase, wherein the heat of heating and separating tower still partly comes from the heat that the knockout tower reboiler reclaims the logistics of dehydration tower still.
The tower top pressure of deammoniation tower is counted 1.5～2.0MPa with gauge pressure in the technique scheme, and tower still temperature is 105～160 ℃, and stage number is 14～65 blocks of theoretical trays, cat head material partial reflux, and reflux ratio is 0.5～3.0; The tower top pressure of extraction tower is counted 0.7～1.1MPa with gauge pressure, tower still temperature is 135～195 ℃, and stage number is 15～63 blocks of theoretical trays, cat head material Trimethylamine 99 partial reflux, reflux ratio is 0.5～5.0, and the extraction water position is the 1st～8 block of theoretical tray on tower top; The tower top pressure of dehydration tower is counted 0.4～0.8MPa with gauge pressure, and tower still temperature is 145～195 ℃, and stage number is 18～65 blocks of theoretical trays, cat head material partial reflux, and reflux ratio is 2.5～6.0; The tower top pressure of knockout tower is counted 0.4～0.8MPa with gauge pressure, tower still temperature is 65～150 ℃, and stage number is 25～70 blocks of theoretical trays, cat head material partial reflux, reflux ratio is 3.0～12.0, side line gas phase or liquid phase extract out the position the total stage number of knockout tower 80～98% between; The flow through temperature difference of reboiler of dehydration tower still logistics is 5～100 ℃.
The present invention obtains Monomethylamine, dimethylamine and Trimethylamine 99 by adopting four-column process flow simultaneously in same flow process.In addition because the tower bottoms of dehydration tower is moisture, methyl alcohol and a small amount of heavy component reclaims the heat rear section as cycling extraction water through the knockout tower reboiler, saved the consumption of fresh water on the one hand in a large number, reduce the generation of a large amount of waste water, can not cause the accumulation of a small amount of heavy component in extraction tower and dehydration tower; Owing to utilized the higher damp and hot thermal source of dehydration tower still liquid temp, reduced the steam consumption of methylamine tripping device on the other hand, obtained effect preferably as the heating of separation tower bottoms.
Fig. 1 is a methylamine separation process scheme of the present invention.
The logistics 1 that comes from the aminating reaction device among Fig. 1 contains monomethyl amine, dimethylamine, trimethylamine, ammonia, methyl alcohol, water and a small amount of Heavy component, liquid phase enters deammoniation tower 2 middle parts, ammonia and part trimethylamine steam from cat head with the form of azeotropic mixture, after the condensation Partial reflux, logistics 3 loops back reactor. Deammoniation tower 2 tower reactor logistics 4 directly enter the middle part of extraction tower 5, extraction tower Utilize the principle of extracting rectifying, take water as extractant, from logistics 4, extract trimethylamine product 6. Extraction tower 5 tower reactor things Stream 7 usefulness pumps are squeezed into the middle part of dehydrating tower 8, and monomethyl amine and dimethylamine steam from cat head, reflux in the condensation rear section, and logistics 9 is advanced Enter knockout tower 13, water, methyl alcohol and a small amount of heavy component then flow out from tower reactor, go knockout tower reboiler 18 to carry out heat exchange, Be divided into two bursts of logistics 10 and logistics 11 after reclaiming heat, logistics 10 circulations are as extraction water, and Methanol Recovery is gone in 11 of logistics Tower reclaims methyl alcohol. After recycling waste water logistics 10 and the fresh water 12 of adding mix, be cooled to 70～90 ℃ through cooler 16 Temperature enters the top of extraction tower 5. At knockout tower 13, monomethyl amine product 14 steams from cat head, and dimethylamine is under knockout tower Section's side line gas phase is extracted out, and after condensation, part is returned knockout tower 13, and part is separated tower bottoms as dimethylamine finished product 15 17 return the dehydrating tower charging aperture; Knockout tower has two reboilers, the still liquid heating of reboiler 18 usefulness dehydrating towers 8, in addition Reboiler 19 usefulness steam 20 heat, and control the sensitive spot temperature of knockout tower hypomere with the heating steam flow.
The invention will be further elaborated below by embodiment: [embodiment 1]
Certain methylamine device reaction liquid contains 596.3 kilograms/hour of ammonia, 9.8 kilograms/hour of methyl alcohol, 257.9 kilograms/hour of Monomethylamines, 300.6 kilograms/hour of dimethylamine, 343.0 kilograms/hour of Trimethylamine 99s, 313.7 kilograms/hour in water, 65 ℃ of temperature, liquid phase enters deammoniation tower.This cat head working pressure is 1.5MPa, 41.8 ℃ of top temperature, 125.4 ℃ of still temperature.596.3 kilogram/hour unreacted ammonia and 130.9 kilograms of/hour Trimethylamine 99s steam from cat head with the form of azeotrope, and loop back reactive system; Tower still extraction liquid is to extraction tower.Extracting rectifying cat head working pressure is 0.9MPa, and the top temperature is 82.3 ℃, 163.3 ℃ of still temperature.Mix and after being cooled to 85 ℃ through 611.3 kilograms/hour of 1222.6 kilograms/hour and 32 ℃ additional fresh waters of knockout tower reboiler heat exchange 90 ℃ of cycling extraction water afterwards from the dehydration tower still, enter the top of extraction tower, cat head obtains 212.2 kilograms/hour of the Trimethylamine 99 products of 99.5% (weight), tower bottoms with enter dehydration tower after the knockout tower still mixes.The dehydration column overhead working pressure is 0.6MPa, and the top temperature is 55.2 ℃, 166.3 ℃ of still temperature.The cat head discharging is added to the knockout tower middle part, tower still discharging material to the knockout tower reboiler heating tower reclaims the sensible heat of dehydration tower high-temperature kettle liquid, and temperature is reduced to 90 ℃ from 166.3 ℃, 1222.6 kilogram/hour as cycling extraction water, 933.0 kilograms of/hour tower bottomss advance methanol distillation column.Knockout tower cat head working pressure is 0.6MPa, and the top temperature is 49.6 ℃, 68.7 ℃ of still temperature.256.3 kilograms/hour of the anhydrous Monomethylamine products of cat head extraction, 300.6 kilograms/hour of bottom side line extraction anhydrous dimethyl amine.Tower bottoms loops back the dehydration tower charging.The knockout tower reboiler heats with the dehydration tower bottoms, and knockout tower hypomere sensitive spot temperature is by the heating steam flow control of another reboiler, and the sensitive spot temperature is controlled to be 65.5 ℃ to 67.5 ℃.
After using the present invention, recyclable 193.4 kilowatts heat energy is amounted to steam consumption and is reduced by 347.8 kilograms/hour (vapor pressure 1.0MPa), reduces 7.2 kilograms/hour of recirculated cooling waters.It is 3102.8 kilograms/hour (vapor pressure 1.0MPa) that this device centrifugal station consumes steam, consumes recirculated cooling water 146.0 * 10
3Kilogram/hour (temperature difference is 10.0 ℃) consumes fresh water (temperature is 32.0 ℃) 611.3 kilograms/hour, and wastewater discharge (advancing methanol distillation column) is 933.0 kilograms/hour.[comparative example 1]
Certain methylamine device reaction liquid contains 596.3 kilograms/hour of ammonia, 9.8 kilograms/hour of methyl alcohol, 257.9 kilograms/hour of Monomethylamines, 300.6 kilograms/hour of dimethylamine, 343.0 kilograms/hour of Trimethylamine 99s, 313.7 kilograms/hour in water, 65 ℃ of temperature, liquid phase enters deammoniation tower.This cat head working pressure is 1.5MPa, 41.8 ℃ of top temperature, 125.4 ℃ of still temperature.596.3 kilogram/hour unreacted ammonia and 130.9 kilograms of/hour Trimethylamine 99s steam from cat head with the form of azeotrope, and loop back reactive system; Tower still extraction liquid is to extraction tower.Extracting rectifying cat head working pressure is 0.9MPa, and the top temperature is 82.3 ℃, 163.3 ℃ of still temperature.1833.9 kilograms/hour of fresh extraction water enter the top of extraction tower after being steam heated to 85 ℃, cat head obtains 212.2 kilograms/hour of the Trimethylamine 99 products of 99.5% (weight), tower bottoms with enter dehydration tower after the knockout tower still mixes.The dehydration column overhead working pressure is 0.6MPa, and the top temperature is 55.2 ℃, 166.3 ℃ of still temperature.The cat head discharging is added to the knockout tower middle part, and 2155.6 kilograms of/hour tower bottomss do not circulate and directly advance methanol distillation column as extraction water.Knockout tower cat head working pressure is 0.6MPa, and the top temperature is 49.6 ℃, 68.7 ℃ of still temperature.256.3 kilograms/hour of the anhydrous Monomethylamine products of cat head extraction, 300.6 kilograms/hour of bottom side line extraction anhydrous dimethyl amine.Tower bottoms loops back the dehydration tower charging.
It is 3600.1 kilograms/hour (vapor pressure 1.0MPa) that this device centrifugal station consumes steam, consumes recirculated cooling water 146.0 * 10
3Kilogram/hour (temperature difference is 10.0 ℃) consumes fresh water (temperature is 32.0 ℃) 1833.9 kilograms/hour, and wastewater discharge (advancing methanol distillation column) is 2155.6 kilograms/hour.
Claims (6)
1, a kind of aminomethane separation method in turn includes the following steps:
A) contain the raw material of ammonia, Monomethylamine, dimethylamine, Trimethylamine 99, first alcohol and water, liquid phase enters the deammoniation tower middle part, and ammonia and part Trimethylamine 99 steam from the deammoniation tower cat head with the azeotrope form, reflux through the condensation rear section, and another part loops back reactor;
B) logistics of deamination Tata still enters the extraction tower middle part, and extraction agent enters from extraction tower top, extracts Trimethylamine 99 at the extraction tower top, and extraction agent is made up of fresh water and partial dehydration tower bottoms;
C) logistics of extraction tower still and from the knockout tower still logistics converges the back as dehydration tower middle part feed material, Monomethylamine and dimethylamine steam from dehydration column overhead, a part passes back into dehydration tower, a part is as knockout tower middle part feed material, a part is as extraction agent after the knockout tower reboiler reclaims heat for the logistics of dehydration tower still, and another part goes methanol distillation column to reclaim methyl alcohol;
D) enter the material of knockout tower, after knockout tower separated, Monomethylamine steamed from the knockout tower cat head, and dimethylamine is extracted out from knockout tower bottom side line gas phase or liquid phase, wherein the heat of heating and separating tower still partly comes from the heat that the knockout tower reboiler reclaims the logistics of dehydration tower still.
2, according to the described aminomethane separation method of claim 1, the tower top pressure that it is characterized in that deammoniation tower is counted 1.5～2.0MPa with gauge pressure, tower still temperature is 105～160 ℃, and stage number is 14～65 blocks of theoretical trays, and the reflux ratio of cat head material partial reflux is 0.5～3.0.
3, according to the described aminomethane separation method of claim 1, the tower top pressure that it is characterized in that extraction tower is counted 0.7～1.1MPa with gauge pressure, tower still temperature is 135～195 ℃, stage number is 15～63 blocks of theoretical trays, cat head material Trimethylamine 99 partial reflux, reflux ratio is 0.5～5.0, and the extraction water position is the 1st～8 block of theoretical tray on tower top.
4, according to the described aminomethane separation method of claim 1, the tower top pressure that it is characterized in that dehydration tower is counted 0.4～0.8MPa with gauge pressure, and tower still temperature is 145～195 ℃, and stage number is 18～65 blocks of theoretical trays, cat head material partial reflux, reflux ratio are 2.5～6.0.
5, according to the described aminomethane separation method of claim 1, the tower top pressure that it is characterized in that knockout tower is counted 0.4～0.8MPa with gauge pressure, tower still temperature is 65～150 ℃, stage number is 25～70 blocks of theoretical trays, cat head material partial reflux, reflux ratio is 3.0～12.0, side line gas phase or liquid phase extract out the position the total stage number of knockout tower 80～98% between.
6,, it is characterized in that the flow through temperature difference of knockout tower reboiler of dehydration tower still logistics is 5～100 ℃ according to the described aminomethane separation method of claim 1.
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| CNB001165356A CN1163468C (en) | 2000-06-15 | 2000-06-15 | Aminomethane separation method |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102942488A (en) * | 2012-11-02 | 2013-02-27 | 天津大学 | Regeneration technology of recovered methylamine solution and device thereof |
| CN107311871A (en) * | 2017-05-16 | 2017-11-03 | 天津大学 | The process for separation and purification of monomethyl amine diformazan amine blends in a kind of synthetic methylamine system |
| CN111732515A (en) * | 2020-06-30 | 2020-10-02 | 北京诺维新材科技有限公司 | Method for separating methylamine |
| CN111792998A (en) * | 2020-06-30 | 2020-10-20 | 北京诺维新材科技有限公司 | Method for separating methylamine |
| CN113842852A (en) * | 2021-10-29 | 2021-12-28 | 聊城鲁西甲胺化工有限公司 | Process and system for annual production of 20 ten thousand tons of methylamine |
| WO2023123523A1 (en) * | 2021-12-27 | 2023-07-06 | 山东天成万丰投资有限公司 | Device for producing trimethylamine for synthesizing cation etherifying agent |
-
2000
- 2000-06-15 CN CNB001165356A patent/CN1163468C/en not_active Expired - Lifetime
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102942488A (en) * | 2012-11-02 | 2013-02-27 | 天津大学 | Regeneration technology of recovered methylamine solution and device thereof |
| CN102942488B (en) * | 2012-11-02 | 2014-10-15 | 天津大学 | Regeneration technology of recovered methylamine solution and device thereof |
| CN107311871A (en) * | 2017-05-16 | 2017-11-03 | 天津大学 | The process for separation and purification of monomethyl amine diformazan amine blends in a kind of synthetic methylamine system |
| CN111732515A (en) * | 2020-06-30 | 2020-10-02 | 北京诺维新材科技有限公司 | Method for separating methylamine |
| CN111792998A (en) * | 2020-06-30 | 2020-10-20 | 北京诺维新材科技有限公司 | Method for separating methylamine |
| CN113842852A (en) * | 2021-10-29 | 2021-12-28 | 聊城鲁西甲胺化工有限公司 | Process and system for annual production of 20 ten thousand tons of methylamine |
| WO2023123523A1 (en) * | 2021-12-27 | 2023-07-06 | 山东天成万丰投资有限公司 | Device for producing trimethylamine for synthesizing cation etherifying agent |
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