CN101973948A - Method for producing melamine - Google Patents
Method for producing melamine Download PDFInfo
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- CN101973948A CN101973948A CN2010102827025A CN201010282702A CN101973948A CN 101973948 A CN101973948 A CN 101973948A CN 2010102827025 A CN2010102827025 A CN 2010102827025A CN 201010282702 A CN201010282702 A CN 201010282702A CN 101973948 A CN101973948 A CN 101973948A
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- trimeric cyanamide
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Abstract
The invention discloses a method for producing melamine. Aiming to solve the problem of huge energy consumption in a tail gas circular pressurizing process in the production process of the melamine, through an optimized process design, the invention provides the method in which the production of melamine is carried out in different pressure sections and in a composite process of plural circulation and non-circulation, wherein primary tail gas is taken as carrier gas by secondary tail gas, and the secondary tail gas is not pressurized by a compressor and directly enters a reactor by utilizing over-bottom pressure of the tail gas, and thus, the compression process of the part of the gas is omitted, and the power consumption of the part of the gas is correspondingly reduced.
Description
Technical field
The invention belongs to chemical production technical field, relate in particular to a kind of Production of Cyanuramide technology.
Background technology
Present liquid phase method Melamine Production Technology that generally adopts in the world and domestic single stage method gas phase quenching, two step method recrystallization production technology, the building-up process of trimeric cyanamide is all finished under (referring to that reactor inlet pressure is to the tail gas washing tower top hole pressure) between same pressure zone.The production technique of prior art is: fusing urea is pumped to reactor urea through urine and adds under inlet, the effect in atomization gas atomizing and go forward side by side in the reactor, and under the high temperature of a MPa gauge pressure and 390 ℃, through catalyst action, reaction generates trimeric cyanamide.The heat that reacts required is provided by the fused salt system.The fluidized-bed carrier gas hang oneself purification, cool off and the preheating of boosting after ammonia, carbon dioxide gas mixture.Reacted gaseous product, by product and carrier gas enter interchanger, hot gas filtration device, the solid impurities such as catalyzer in the filtering air-flow after cyclonic separator reclaims the catalyst particle that most of air-flow carries secretly.The hot gas filtration device is a pocket type blowback structure, is provided with two, and when filter resistance rose to prescribed value, each continued operation with strainer to switch to another.The dustless gas that comes out from strainer is entered in the crystallizer by the crystallizer top, mixes with 140 ℃ of cold process gas of coming up from the bottom.Temperature is reduced to 210 ℃ by 320 ℃, the trimeric cyanamide crystallization is separated out, enter together in the finished product cyclonic separator with gas mixture, the separated whirlwind bottom that gathers of trimeric cyanamide, sent separator by scraper and pressure spiral, through gas blower gas delivery, cooling, promptly get the trimeric cyanamide product through fly-ash separator separation, packing.
The trimeric cyanamide dust and the urea of complete reaction not that contain trace from the gas that comes out in finished product cyclonic separator top enter after blower fan boosts in the liquid urine washing tower, and by liquid urine washing, purifying and cooling back branch three tunnel: the first via is after the carrier gas compressor boosts
Carrier gas recycles as reaction bed, and the second the tunnel returns crystallizer recycles as quenching gas, and Third Road advances exhaust treatment system.
The problem that the production technique of prior art exists is: the building-up process of trimeric cyanamide is all finished under (referring to that reactor inlet pressure is to the tail gas washing tower top hole pressure) between same pressure zone, partial reaction tail gas after the separation of melamine is returned reactor and is done the reaction carrier gas after recycle compressor boosts, the a large amount of electric energy of tail gas circulating pressurized process consumption, cause energy dissipation, and product cost is raise.
Summary of the invention
Purpose of the present invention is exactly the tail gas circulation pressure process that exists at preparation technology of melamine in the prior art, consume the problem of a large amount of energy, by optimizing technological design, provide a kind of make Production of Cyanuramide in the different pressures interval, a plurality of circulation+do not carry out under the round-robin recombination process, energy-saving and cost-reducing novel process.
The objective of the invention is to be achieved through the following technical solutions: fusing urea is pumped to reactor urea through urine and adds inlet, atomizing is gone forward side by side in the reactor under the effect of atomization gas, through interchanger, the hot gas filtration device, crystallizer, isolate the trimeric cyanamide product at the trimeric cyanamide separator, the trimeric cyanamide dust and the urea of complete reaction not that from the gas that comes out in trimeric cyanamide separator top, contain trace, after boosting, blower fan enters in the urine washing tower, divided three the tunnel by urine washing, purifying and cooling back: carrier gas recycles the first via as reaction bed after the carrier gas compressor boosts, the second the tunnel returns crystallizer recycles as quenching gas, and Third Road advances the next stage production system.
The pressure that carrier gas enters reactor is a MPa, is b MPa to the tail gas pressure that goes out behind the urine washing tower.
The pressure that preferred carrier gas enters reactor is 1.2MPa, is 1.0MPa to the tail gas pressure that goes out behind the urine washing tower.
Tail gas enters next production cycle system under b MPa pressure, enter reactor by the reactor bottom inlet after heating.Fusing urea adds inlet through being pumped to reactor urea, atomizing is gone forward side by side in the reactor under the effect of atomization gas, pass through the hot gas filtration device again, crystallizer, the trimeric cyanamide separator, a part forms finished product, some contains the trimeric cyanamide dust and the urea of complete reaction not of trace from the gas that comes out in trimeric cyanamide separator top, after boosting, blower fan enters in the urine washing tower, divided two the tunnel by urine washing, purifying and cooling back: the first via is returned crystallizer and is recycled as quenching gas, and the second the tunnel advances next stage production cycle system or exhaust treatment system.
The pressure that carrier gas enters reactor is approximately b MPa, is c MPa to the tail gas pressure that goes out behind the urine washing tower.
The pressure that preferred carrier gas enters reactor is approximately 1.0MPa, is 0.8MPa to the tail gas pressure that goes out behind the urine washing tower.The gaseous tension that promptly advances next stage production system or exhaust treatment system is c MPa, by that analogy.
Tail gas behind the second stage is done carrier gas,, directly utilizes the tail gas overbottom pressure to enter the next stage reactor without compressor pressurizes,
According to the size of height and every grade of pressure reduction of first step pressure, multistage Production of Cyanuramide process can be set as mentioned above.
Beneficial effect of the present invention: the tail gas behind the second stage is done carrier gas,, directly utilize the tail gas overbottom pressure to enter reactor, then saved the compression process of this portion gas, saved the power consumption of this portion gas compression accordingly without compressor pressurizes.
Description of drawings
Describe embodiments of the invention in detail below in conjunction with accompanying drawing
Fig. 1 is the preparation technology of melamine schema of prior art
Fig. 2 is a preparation technology of melamine schema of the present invention
Embodiment
Fusing urea is pumped to reactor urea through urine and adds under population, the effect in atomization gas atomizing and go forward side by side in the reactor, and under the high temperature of 1.2MPa gauge pressure and 390 ℃, through catalyst action, reaction generates trimeric cyanamide.The heat that reacts required is provided by the fused salt system.The fluidized-bed carrier gas hang oneself purification, cool off and the preheating of boosting after ammonia, carbon dioxide gas mixture.Reacted gaseous product, by product and carrier gas enter interchanger, hot gas filtration device, the solid impurities such as catalyzer in the filtering air-flow after cyclonic separator reclaims the catalyst particle that most of air-flow carries secretly.The hot gas filtration device is a pocket type blowback structure, is provided with two, when filter resistance rises to prescribed value, switches to another reserve filter and continues operation.The dustless gas that comes out from strainer is entered in the crystallizer by the crystallizer top, mixes with 140 ℃ of cold process gas of coming up from the bottom.Temperature is reduced to 210 ℃ by 320 ℃, the trimeric cyanamide crystallization is separated out, enter together in the finished product cyclonic separator with gas mixture, the separated whirlwind bottom that gathers of trimeric cyanamide, sent separator by scraper and pressure spiral, through gas blower gas delivery, cooling, promptly get the trimeric cyanamide product through fly-ash separator separation, packing.
The trimeric cyanamide dust and the urea of complete reaction not that from the gas that comes out in finished product cyclonic separator top, contain trace, after boosting, blower fan enters in the liquid urine washing tower, divided three the tunnel by liquid urine washing, purifying and cooling back: carrier gas recycles the first via as reaction bed after the carrier gas compressor boosts, the second the tunnel returns crystallizer recycles as quenching gas, and Third Road tail gas advances the next stage production system.
The pressure that carrier gas enters reactor is 1.2MPa, is 1.0MPa to the tail gas pressure that goes out behind the urine washing tower.
Tail gas directly enters next production system under 1.0MPa pressure, enter reactor by the reactor bottom inlet after heating.Fusing urea adds under population, the effect in atomization gas atomizing and goes forward side by side in the reactor through being pumped to reactor urea, and under the high temperature of approximate 1.0MPa gauge pressure and 390 ℃, through catalyst action, reaction generates trimeric cyanamide.The heat that reacts required is provided by the fused salt system.The fluidized-bed carrier gas hang oneself purification, cool off and the preheating of boosting after ammonia, carbon dioxide gas mixture.Reacted gaseous product, by product and carrier gas enter interchanger, hot gas filtration device, the solid impurities such as catalyzer in the filtering air-flow after cyclonic separator reclaims the catalyst particle that most of air-flow carries secretly.The hot gas filtration device is a pocket type blowback structure, is provided with two, when filter resistance rises to prescribed value, switches to another reserve filter and continues operation.The dustless gas that comes out from strainer is entered in the crystallizer by the crystallizer top, mixes with 140 ℃ of cold process gas of coming up from the bottom.Temperature is reduced to 210 ℃ by 320 ℃, the trimeric cyanamide crystallization is separated out, enter together in the finished product cyclonic separator with gas mixture, the separated whirlwind bottom that gathers of trimeric cyanamide, sent separator by scraper and pressure spiral, through gas blower gas delivery, cooling, promptly get the trimeric cyanamide product through fly-ash separator separation, packing.
The trimeric cyanamide that from the gas that comes out in finished product cyclonic separator top, contains trace.
Claims (4)
1. method for producing melamine, fusing urea is pumped to reactor urea through urine and adds inlet, atomizing is gone forward side by side in the reactor under the effect of atomization gas, the pressure that carrier gas enters reactor is a MPa, through interchanger, the hot gas filtration device, enter the trimeric cyanamide separator behind the crystallizer, the trimeric cyanamide dust and the urea of complete reaction not that from the gas that comes out in trimeric cyanamide separator top, contain trace, after boosting, blower fan enters in the urine washing tower, by liquid urine washing, purifying and cooling back tail gas pressure is b MPa, and divides three the tunnel: carrier gas recycles the first via as reaction bed after the carrier gas compressor boosts.The second the tunnel returns crystallizer recycles as quenching gas.It is characterized in that Third Road tail gas need not pass through the carrier gas compressor pressurizes, directly under b MPa pressure, enter the next stage production system, after heating, enter reactor by next stage reactor bottom inlet, fusing urea adds inlet through being pumped to reactor urea, atomizing is gone forward side by side in the reactor under the effect of atomization gas, pass through interchanger again, the hot gas filtration device, crystallizer, isolate the trimeric cyanamide finished product at the trimeric cyanamide separator, the trimeric cyanamide dust and the urea of complete reaction not that from the gas that comes out in trimeric cyanamide separator top, contain trace, after boosting, blower fan enters in the urine washing tower, after urine washing, purifying and cooling, tail gas pressure is c MPa, and divide two the tunnel: the first via is returned crystallizer and is recycled as quenching gas, and the second the tunnel enters next stage production cycle system or exhaust treatment system.Promptly the tail gas behind the second stage is done carrier gas,, directly utilize the tail gas overbottom pressure to enter the next stage reactor without compressor pressurizes.
2. a kind of Production of Cyanuramide method according to claim 1 is characterized in that the pressure that carrier gas enters reactor is 1.2MPa, is 1.0MPa to the tail gas pressure that goes out behind the urine washing tower, and its tail gas directly enters the next stage production system.
3. a kind of Production of Cyanuramide method according to claim 1 is characterized in that the pressure that carrier gas enters reactor is b MPa, is c MPa to the tail gas pressure that goes out behind the urine washing tower, and its tail gas directly enters the next stage production system.
4. according to claim 1 or 3 described a kind of Production of Cyanuramide methods, it is characterized in that the pressure that carrier gas enters reactor is 1.0MPa, be 0.8MPa to the tail gas pressure that goes out behind the urine washing tower, its tail gas directly enters the next stage production system.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010282702 CN101973948B (en) | 2010-09-11 | 2010-09-11 | Method for producing melamine |
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| Application Number | Priority Date | Filing Date | Title |
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| CN 201010282702 CN101973948B (en) | 2010-09-11 | 2010-09-11 | Method for producing melamine |
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| CN101973948A true CN101973948A (en) | 2011-02-16 |
| CN101973948B CN101973948B (en) | 2013-03-27 |
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| CN 201010282702 Expired - Fee Related CN101973948B (en) | 2010-09-11 | 2010-09-11 | Method for producing melamine |
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102489095A (en) * | 2011-10-27 | 2012-06-13 | 山东省舜天化工集团有限公司 | Method for purifying melamine tail gas |
| CN102558079A (en) * | 2011-12-30 | 2012-07-11 | 南通紫鑫实业有限公司 | Process for producing melamine |
| CN102584730A (en) * | 2012-03-12 | 2012-07-18 | 李靖铭 | Equipment and process for producing melamine under low pressure |
| CN104292173A (en) * | 2014-09-08 | 2015-01-21 | 山东省舜天化工集团有限公司 | Melamine crystallizer-based gas heat recovery method |
| CN111983136A (en) * | 2020-07-30 | 2020-11-24 | 青岛惠城环保科技股份有限公司 | Melamine catalyst performance evaluation equipment |
| CN115073389A (en) * | 2022-07-01 | 2022-09-20 | 山东省舜天化工集团有限公司 | Energy-saving melamine production system and production method |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1188761A (en) * | 1998-02-24 | 1998-07-29 | 蒋大洲 | Preparation technology of melamine and its device |
| CN1657526A (en) * | 2004-02-17 | 2005-08-24 | 山东海化魁星化工有限公司 | Process for preparing melamine |
| WO2009080176A2 (en) * | 2007-12-20 | 2009-07-02 | Dsm Ip Assets B.V. | Process for the preparation of melamine |
| WO2009138450A1 (en) * | 2008-05-14 | 2009-11-19 | Urea Casale S.A. | Process for producing high-quality melamine from urea |
-
2010
- 2010-09-11 CN CN 201010282702 patent/CN101973948B/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1188761A (en) * | 1998-02-24 | 1998-07-29 | 蒋大洲 | Preparation technology of melamine and its device |
| CN1657526A (en) * | 2004-02-17 | 2005-08-24 | 山东海化魁星化工有限公司 | Process for preparing melamine |
| WO2009080176A2 (en) * | 2007-12-20 | 2009-07-02 | Dsm Ip Assets B.V. | Process for the preparation of melamine |
| WO2009138450A1 (en) * | 2008-05-14 | 2009-11-19 | Urea Casale S.A. | Process for producing high-quality melamine from urea |
Non-Patent Citations (1)
| Title |
|---|
| 郭慧 等: "常压法三聚氰胺生产工艺", 《辽宁化工》 * |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102489095A (en) * | 2011-10-27 | 2012-06-13 | 山东省舜天化工集团有限公司 | Method for purifying melamine tail gas |
| CN102558079A (en) * | 2011-12-30 | 2012-07-11 | 南通紫鑫实业有限公司 | Process for producing melamine |
| CN102558079B (en) * | 2011-12-30 | 2014-06-25 | 南通紫鑫实业有限公司 | Process for producing melamine |
| CN102584730A (en) * | 2012-03-12 | 2012-07-18 | 李靖铭 | Equipment and process for producing melamine under low pressure |
| CN102584730B (en) * | 2012-03-12 | 2014-08-27 | 李靖铭 | Equipment and process for producing melamine under low pressure |
| CN104292173A (en) * | 2014-09-08 | 2015-01-21 | 山东省舜天化工集团有限公司 | Melamine crystallizer-based gas heat recovery method |
| CN111983136A (en) * | 2020-07-30 | 2020-11-24 | 青岛惠城环保科技股份有限公司 | Melamine catalyst performance evaluation equipment |
| CN115073389A (en) * | 2022-07-01 | 2022-09-20 | 山东省舜天化工集团有限公司 | Energy-saving melamine production system and production method |
| CN115073389B (en) * | 2022-07-01 | 2023-10-31 | 山东省舜天化工集团有限公司 | Energy-saving melamine production system and production method |
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| CN101973948B (en) | 2013-03-27 |
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