CN104892463A - Process for producing biurea through optimized urea method - Google Patents
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- CN104892463A CN104892463A CN201510180600.5A CN201510180600A CN104892463A CN 104892463 A CN104892463 A CN 104892463A CN 201510180600 A CN201510180600 A CN 201510180600A CN 104892463 A CN104892463 A CN 104892463A
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Abstract
The present invention discloses a process for producing biurea through an optimized urea method. The process comprises that: during the biurea preparing, the crude solution of hydrazine hydrate produced through the urea method is adopted as a raw material and is subjected to repeated evaporation concentration and freezing crystallization for a plurality of times to respectively separate out sodium chloride and sodium carbonate so as to obtain a fine hydrazine solution of the hydrazine hydrate; the sodium chloride is separated at the evaporation section and the sodium carbonate decahydrate is separated at the freezing crystallization section during each evaporation, a salt extracting pump is used to extract, and the solid sodium chloride is separated out by a salt separation centrifuge; and the liquid is subjected to freezing crystallization, is separated, and then returns to the cold hydrazine solution at the evaporation section, pre-cooling is performed, and then the obtained material is conveyed to the crystallization kettle. The process of the present invention has the following beneficial effects that: the hydrazine hydrate-containing crude solution produced through the urea method is adopted as the raw material, alkali removing through freezing is performed while the cold energy and the heat energy are recovered, the repeated circulating method is used, the hydrazine hydrate concentration is improved in the low cost manner, and the process has characteristics of less raw material consumption, less energy source consumption, low cost, and high single-kettle yield during condensation.
Description
Technical field
The present invention relates to the technical field of hydrazo-dicarbonamide, be specifically related to a kind of technique optimizing Wyler's process production hydrazo-dicarbonamide.
Background technology
Hydrazo-dicarbonamide is white solid or powder, molecular formula: C
2h
6n
4o
2, molecular weight: 118, water fast, fusing point 247-250 DEG C, hydrazo-dicarbonamide is mainly for the production of ADC whipping agent.
Conventional Wyler's process is produced hydrazo-dicarbonamide technique and is divided into acid system and pure hydrazine method two kinds.
Conventional acid system mainly adopt produced by Wyler's process after freezing and crystallizing cutting out partial Sodium carbonate decahydrate, obtain concentration of hydrazine hydrate containing the thick solution of < 70g/L hydrazine hydrate and bring up to the rare smart hydrazine liquid being less than about 10%, to add in sulfuric acid or hydrochloric acid and after react under the temperature condition of > 100 DEG C with urea again and generate hydrazo-dicarbonamide.Because carbonate content in smart hydrazine liquid is still at 45-60g/L, need a large amount of consumption sulfuric acid or hydrochloric acid, simultaneously because hydrazine hydrate content is low, when condensation, each still yields poorly, and under identical condensation temp and reaction times, certainly will for reaction heat the heat that consume and manpower and materials all high.
And the smart hydrazine liquid that this law is produced is containing hydrazine hydrate 15-40%, it is 3-6 times of ordinary method concentration of hydrazine hydrate, thus when condensation, the output of each still is high 3 to 5 times, simultaneously because carbonate content in smart hydrazine liquid is low, with middle strong acid sulfuric acid, hydrochloric acid, phosphoric acid, weak acetic acid, propionic acid etc. neutralize, thus can reclaim the by products such as valuable ammonium salt.Product also can separately and urea condensation produce hydrazo-dicarbonamide.
Conventional hydrazine concentrate method mainly adopt by Wyler's process produce containing the thick solution of < 70g/L hydrazine hydrate after freezing and crystallizing cutting out partial Sodium carbonate decahydrate, 40% hydrazine hydrate is obtained again through evaporation (rest materials is gas by vaporizing liquid except nonvolatile salt), rectifying, after adding acid neutralization again, or generate hydrazo-dicarbonamide with urea reaction under acid-free condition.The caustic soda that must add 0.3-0.5 ton/ton hydrazo-dicarbonamide in this evaporative process just can steam hydrazine hydrate in thick solution, and (effect adding caustic soda is that the complete urea reaction of the unreacted in vaporizer in caustic soda and thick solution generates sodium carbonate, and be just conducive to the evaporation of hydrazine hydrate under remaining on highly basic situation), thereby increase the consumption of caustic soda.
Summary of the invention
Object of the present invention is just in order to overcome the deficiency of above-mentioned technology, draw the advantage of acid system and pure hydrazine method two kinds of methods, and a kind of technique that Wyler's process produces hydrazo-dicarbonamide of optimizing is provided, it is Wyler's process hydrazine hydrate concentrate novel process, mainly with the thick solution containing hydrazine hydrate that Wyler's process is produced, through repeated multiple times evaporation concentration, freezing and crystallizing obtains the smart hydrazine liquid of hydrazine content 15 ~ 40%.This technique is that thick for the hydrazine hydrate produced by Wyler's process solution is isolated concentrate after sodium-chlor and sodium carbonate to the smart hydrazine liquid containing 15-40% hydrazine hydrate respectively through repeated multiple times evaporation concentration, freezing and crystallizing.Thus the hydrazine hydrate production raw material of method concentrate and energy consumption few, the single-autoclave yield rate producing hydrazo-dicarbonamide condensation kettle is high, and cost is low.
The object of the invention is to have come by following technical solution.This optimization Wyler's process produces the technique of hydrazo-dicarbonamide, and the method concrete steps are as follows: adopt the thick solution containing < 70g/L hydrazine hydrate produced by Wyler's process to be that raw material isolates through repeated multiple times evaporation concentration, freezing and crystallizing the smart hydrazine liquid obtaining containing 15-40% hydrazine hydrate after sodium-chlor and sodium carbonate respectively when preparing hydrazo-dicarbonamide; When evaporating at every turn, cycles of concentration is 1:0.5-0.6, repeatedly carrying out evaporating, freezing and crystallizing, isolates sodium-chlor at evaporator section and isolates Sodium carbonate decahydrate in freezing and crystallizing section; The precipitated sodium chloride during hydrazine hydrate obtained after at every turn evaporating thick solution, send a point salt whizzer to isolate solid sodium chloride with adopting salt pump extraction; Liquid via be separated after freezing and crystallizing return the cold hydrazine liquid precooling of evaporator section after send in crystallization kettle, then be sent from scheming after being cooled to 0--2 DEG C and isolate Sodium carbonate decahydrate.
Further, the method specifically comprises the steps:
(1) the thick solution containing 46g/L heat by hydrazine hydrate reactor temperature being out 120-130 DEG C is directly sent in vaporizer, carry out evaporation concentration under vacuum to the thick solution containing 70-140g/L hydrazine hydrate, cycles of concentration 1:0.5-0.7, the sodium-chlor of precipitation is sent from scheming simultaneously and isolates solid sodium chloride, now separate out sodium carbonate amount little.
(2) the thick solution obtained by step (1) is after being pre-chilled to 35-45 DEG C, send in crystallization kettle and carry out being cooled to 0 DEG C with chilled brine---after 2 DEG C, the Sodium carbonate decahydrate of separating out is sent from scheming and isolates Sodium carbonate decahydrate xln, obtain the smart hydrazine liquid containing 110-180g/L hydrazine hydrate, now precipitated sodium chloride amount is few.
(3) the smart hydrazine liquid that step (2) obtains is sent in another vaporizer again carry out heating evaporation, be concentrated to the thick solution containing 180-260g/L hydrazine hydrate, cycles of concentration 1:0.5-0.7, is sent from scheming by the sodium-chlor of precipitation simultaneously and isolates solid sodium chloride;
(4) thick solution step (3) obtained is after being pre-chilled to 35-45 DEG C, send in crystallization kettle and carry out being cooled to 0 DEG C with chilled brine again---after 2 DEG C, the Sodium carbonate decahydrate of separating out is sent from scheming and isolates Sodium carbonate decahydrate xln, obtains the smart hydrazine liquid containing 210-230g/L hydrazine hydrate;
(5) by the smart hydrazine liquid repeating step (3) that obtains and step (4) repeatedly, until obtain the refined soln containing 40% hydrazine hydrate.
Further, the method specifically comprises the steps:
(1) will be that 120-130 DEG C send into after precooling in crystallization kettle containing the thick solution of < 70g/L hydrazine hydrate carries out being cooled to 0 DEG C with chilled brine by hydrazine hydrate reactor temperature out---after 2 DEG C, the Sodium carbonate decahydrate of separating out is sent from the part Sodium carbonate decahydrate xln that crystallization is isolated in scheming, obtains the smart hydrazine liquid containing 50-75g/L hydrazine hydrate;
(2) the smart hydrazine liquid that step (1) obtains is sent in vaporizer after preheating, carry out evaporation concentration under vacuum to the thick solution containing 75-160g/L hydrazine hydrate, cycles of concentration 1:0.5-0.7, is sent from scheming by the sodium-chlor of precipitation simultaneously and isolates solid sodium chloride;
(3) the thick solution obtained by step (2) is after being pre-chilled to 35-45 DEG C, send in crystallization kettle and carry out being cooled to 0 DEG C with chilled brine---after 2 DEG C, the Sodium carbonate decahydrate of separating out is sent from scheming and isolates Sodium carbonate decahydrate xln, obtains the smart hydrazine liquid containing 90-200g/L hydrazine hydrate;
(4) the smart hydrazine liquid that step (3) obtains is sent in another vaporizer again evaporate, be concentrated to the thick solution containing 160-250g/L hydrazine hydrate, cycles of concentration 1:0.5-0.7, is sent from scheming by the sodium-chlor of precipitation simultaneously and isolates solid sodium chloride;
(5) thick solution step (4) obtained is after being pre-chilled to 35-45 DEG C, send in crystallization kettle and carry out being cooled to 0 DEG C with chilled brine---after 2 DEG C, the Sodium carbonate decahydrate of separating out is sent from scheming and isolates Sodium carbonate decahydrate xln, obtains the smart hydrazine liquid containing 180-300g/L hydrazine hydrate;
(6) smart hydrazine liquid repeating step (4) and step (5) will be obtained repeatedly, until obtain the refined soln containing 40% hydrazine hydrate.
Repeatedly when evaporation and concentrating and freezing and crystallizing concentrate, there is the alternately heat transfer process of heating and cooling, in order to save energy, heat exchanger can be utilized to realize thermal exchange, thus save energy.The concentration of hydrazine hydrate statement that in above two approach processes, each step is mentioned is conventional value, freely can control, do not affect right of the present invention according to actual production situation.
Beneficial effect of the present invention is: the present invention uses the thick solution containing hydrazine hydrate produced by Wyler's process as raw material, 40% hydrazine hydrate is not produced by existing simple employing rectification process, omit and remove alkali by the thick solution of hydrazine hydrate through freezing, evaporative desalination, rectifying obtain 40% hydrazine hydrate operation, but first evaporate desalination by thick hydrazine, freezing except alkali, reclaim cold and heat simultaneously, the method of iterative cycles, the raising concentration of hydrazine hydrate of low cost, with explained hereafter hydrazo-dicarbonamide of the present invention, raw material and energy consumption few, cost is low, and during condensation, single-autoclave yield rate is high.
Embodiment
Below by embodiment, the present invention is further elaborated, and help is understood the present invention by embodiment better, but the present invention is not limited only to following embodiment.
This optimization Wyler's process of the present invention produces the technique of hydrazo-dicarbonamide, and the method concrete steps are as follows: adopt the thick solution containing < 70g/L hydrazine hydrate produced by Wyler's process to be that raw material isolates through repeated multiple times evaporation concentration, freezing and crystallizing the smart hydrazine liquid obtaining containing 15-40% hydrazine hydrate after sodium-chlor and sodium carbonate respectively when preparing hydrazo-dicarbonamide; When evaporating at every turn, cycles of concentration is 1:0.5-0.6, and repeatedly carrying out evaporating, freezing and crystallizing, isolate sodium-chlor at evaporator section and isolate Sodium carbonate decahydrate in freezing and crystallizing section, evaporation is good with freezing cycle index with 2-4 time.The precipitated sodium chloride during hydrazine hydrate obtained after at every turn evaporating thick solution, send a point salt whizzer to isolate solid sodium chloride with adopting salt pump extraction; Liquid via be separated after freezing and crystallizing return the cold hydrazine liquid precooling of evaporator section after send in crystallization kettle, then be sent from scheming after being cooled to 0--2 DEG C and isolate Sodium carbonate decahydrate.The volume of the thick solution of the hydrazine hydrate obtained after at every turn carrying out evaporation concentration is only the 50-60% of original volume, reduces 40-50% in the chilling requirement consumption of freezing and crystallizing operation institute.Thick hydrazine liquid is replacing in heating and cooling process repeatedly, adopts equipment heat exchanger to carry out thermal exchange, thus save energy.
This technique isolates through repeated multiple times evaporation concentration, freezing and crystallizing the smart hydrazine liquid obtaining containing 15-40% hydrazine hydrate after sodium-chlor and Sodium carbonate decahydrate containing the thick solution of < 70g/L hydrazine hydrate respectively by what produced by Wyler's process.The present invention uses the thick solution containing hydrazine hydrate produced by Wyler's process as raw material, thick hydrazine liquid not in accordance with routine removes alkali through freezing, evaporative desalination, rectifying obtain the operation of 40% hydrazine hydrate, but by repeatedly evaporate, freezing, the concentration of hydrazine hydrate is brought up to 15 ~ 40%.
The present invention produces hydrazo-dicarbonamide, omits and obtains 40% hydrazine hydrate operation by the thick solution of hydrazine hydrate through evaporation, desalination, rectifying, avoids simultaneously and supplements caustic soda when evaporating, thus decrease caustic soda raw material and energy consumption.Technology described in this law is adopted to also achieve the raising of concentration of hydrazine hydrate.
Embodiment 1:
(1) send in hydrazine hydrate reactor after clorox being mixed with urea soln (adding catalyzer), by steam heating to 125 DEG C, the thick solution containing being about 46g/L hydrazine hydrate is obtained after reaction, this solution is directly sent in vaporizer, carry out evaporation concentration under vacuum to the thick solution containing 85g/L hydrazine hydrate, cycles of concentration 1:0.58, concentrated sodium-chlor of separating out is sent from scheming centrifugation and goes out sodium-chlor.What steam to enter in rectifying tower concentrate to the hydrazine hydrate of 10-15% containing the steam of a small amount of hydrazine hydrate.
(2) the thick solution extraction from vaporizer obtained by (1), send after being under agitation cooled with circulating water 35-45 DEG C in pre-cold trap, send after carrying out being cooled to 0 DEG C with chilled brine in crystallization kettle, isolate the Sodium carbonate decahydrate forming xln, obtain the smart hydrazine liquid containing 106g/L hydrazine hydrate.
(3) the smart hydrazine liquid (2) obtained is sent in another vaporizer after preheating again, carries out evaporation concentration under vacuum to the thick solution containing 145g/L hydrazine hydrate, cycles of concentration 1:0.78.What steam to enter in rectifying tower concentrate to the hydrazine hydrate of 10-15% containing the steam of a small amount of hydrazine hydrate.Concentrated sodium-chlor of separating out is sent from scheming centrifugation and goes out sodium-chlor.
(4) the thick solution extraction from vaporizer obtained by (3), send after being under agitation cooled with circulating water 35-45 DEG C in pre-cold trap, send after carrying out being cooled to 0 DEG C with chilled brine in crystallization kettle, isolate the Sodium carbonate decahydrate forming xln, obtain the smart hydrazine liquid containing 175g/L hydrazine hydrate.
(5) repeating step (3) and (4) are until obtain the smart hydrazine liquid containing 40% hydrazine hydrate.
(6) the smart hydrazine liquid obtained by (5) adds after sulfuric acid or hydrochloric acid or phosphoric acid neutralize pH value 2-5 and adds urea reaction generation hydrazo-dicarbonamide in condensation kettle again.Condensation kettle slurry out through suction filtration, washing, centrifugal, be drying to obtain hydrazo-dicarbonamide product.
(7) solution of the hydrazine hydrate obtained through step (1)-(5) each step, all can be used for step
Embodiment 2:
(1) by after by hydrazine hydrate reactor temperature being out 125 DEG C send into after precooling and carry out being cooled to 0 DEG C with chilled brine containing the thick solution of 46g/L hydrazine hydrate in crystallization kettle, the Sodium carbonate decahydrate of separating out is sent from scheming and isolates Sodium carbonate decahydrate xln, obtains the smart hydrazine liquid containing 53g/L hydrazine hydrate.
(2) the smart hydrazine liquid (1) obtained is sent in vaporizer after preheating, carry out evaporation concentration under vacuum to the thick solution containing 85g/L hydrazine hydrate, cycles of concentration 1:0.65, is sent from scheming by the sodium-chlor of precipitation simultaneously and isolates solid sodium chloride.What steam to enter in rectifying tower concentrate to the hydrazine hydrate of 10-15% containing the steam of a small amount of hydrazine hydrate.
(3) the thick solution obtained by (2) is after being pre-chilled to 35-45 DEG C, send after being cooled to 0 DEG C with chilled brine in crystallization kettle, the Sodium carbonate decahydrate of separating out is sent from scheming and isolates Sodium carbonate decahydrate xln, obtains the smart hydrazine liquid containing 108g/L hydrazine hydrate.
(4) the smart hydrazine liquid (3) obtained is sent in another vaporizer again and is evaporated, and is concentrated to the thick solution containing 170g/L hydrazine hydrate, cycles of concentration 1:0.65, the sodium-chlor of precipitation is sent from scheming simultaneously and isolates solid sodium chloride.
(5) the thick solution (4) obtained is after being pre-chilled to 35-45 DEG C, send after being cooled to 0 DEG C with chilled brine in crystallization kettle, the Sodium carbonate decahydrate of separating out is sent from scheming and isolates Sodium carbonate decahydrate xln, obtains the smart hydrazine liquid containing 188g/L hydrazine hydrate.
(6) (5) are obtained smart hydrazine liquid repeating step (4) and step (5) repeatedly, until obtain the refined soln containing 40% hydrazine hydrate.
(7) the smart hydrazine liquid obtained by (6) adds after acidic substance are neutralized to pH value 2-5, then adds urea reaction and generate hydrazo-dicarbonamide, is drying to obtain hydrazo-dicarbonamide product through separating, washing.
(8) through the hydrazine hydrate solution that step (1)-(6) obtain, all can be used for step (7).
The present invention uses the thick hydrazine liquid produced by Wyler's process as raw material, directly do not use merely by 40% hydrazine hydrate of evaporation rectifying means acquisition, can omit like this and remove alkali, evaporation desalination by the thick solution of hydrazine hydrate through freezing, rectifying obtains a series of highly energy-consuming operations such as 40% hydrazine hydrate.Hydrazo-dicarbonamide is produced by the present invention, do not need thick solution all to evaporate at evaporization process, only by each for thick solution evaporation concentration to the 40-60% of original volume, steam consumption 40-50% needed for the former evaporation of such saving, decrease 40%-50% by long-pending for the thick hydrazine liquid after at every turn concentrated simultaneously, 40-50% is decreased in each cold requirement of Crystallization Procedure, and gradually reducing because of volume, thus the valuable Sodium carbonate decahydrate than the many 80-95% of former technique can be isolated.The present invention has saved a large amount of energy consumptions than traditional pure hydrazine method, does not need to add caustic soda simultaneously, thus saved the consumption of raw material caustic soda when evaporating thick solution; The present invention is also better than traditional freezing technique except directly synthesizing hydrazo-dicarbonamide after alkali with acid system, mainly be because of hydrazine hydrate content in smart hydrazine liquid be the 3-6 of former technique doubly, improve the single-autoclave yield rate of condensation kettle when condensation, the steam consumption of corresponding condensation kettle saves 3 ~ 6 times; Again due to the minimizing of volume, in smart hydrazine liquid, the amount of sodium carbonate decreases 80-95%, thus the amount adding acidic substance decreases 80-95%, and the consumption of acid declines to a great extent.And the selectivity adding acid strengthens, in also can using except employing strong acid, strong acid is if phosphoric acid, weak acid are as acetic acid, propionic acid; Another advantage is that the Sodium carbonate decahydrate yield reclaimed to 80 ~ 95%, can add the performance of enterprises.The present invention be draw acid system and pure hydrazine method two kinds of methods advantage and this law is proposed.The present invention declines to a great extent in raw material and energy consumption than traditional acid system or pure hydrazine method, and cost is low.
Claims (3)
1. optimizing the technique that Wyler's process produces hydrazo-dicarbonamide, it is characterized in that: the method concrete steps are as follows: adopting when preparing hydrazo-dicarbonamide the thick solution containing < 70g/L hydrazine hydrate produced by Wyler's process to be that raw material isolates through repeated multiple times evaporation concentration, freezing and crystallizing the smart hydrazine liquid obtaining containing 15-40% hydrazine hydrate after sodium-chlor and sodium carbonate respectively; When evaporating at every turn, cycles of concentration is 1:0.5-0.6, repeatedly carrying out evaporating, freezing and crystallizing, isolates sodium-chlor at evaporator section and isolates Sodium carbonate decahydrate in freezing and crystallizing section; The precipitated sodium chloride during hydrazine hydrate obtained after at every turn evaporating thick solution, send a point salt whizzer to isolate solid sodium chloride with adopting salt pump extraction; Liquid via be separated after freezing and crystallizing return the cold hydrazine liquid precooling of evaporator section after send in crystallization kettle, then be sent from scheming after being cooled to 0--2 DEG C and isolate Sodium carbonate decahydrate.
2. optimization Wyler's process according to claim 1 produces the technique of hydrazo-dicarbonamide, it is characterized in that: the method specifically comprises the steps:
(1) the thick solution containing 46g/L heat by hydrazine hydrate reactor temperature being out 120-130 DEG C is directly sent in vaporizer, carry out evaporation concentration under vacuum to the thick solution containing 70-140g/L hydrazine hydrate, cycles of concentration 1:0.5-0.7, is sent from scheming by the sodium-chlor of precipitation simultaneously and isolates solid sodium chloride;
(2) the thick solution obtained by step (1) is after being pre-chilled to 35-45 DEG C, send in crystallization kettle and carry out being cooled to 0 DEG C with chilled brine--after-2 DEG C, the Sodium carbonate decahydrate of separating out is sent from scheming and isolates Sodium carbonate decahydrate xln, obtains the smart hydrazine liquid containing 110-180g/L hydrazine hydrate;
(3) the smart hydrazine liquid that step (2) obtains is sent in another vaporizer again carry out heating evaporation, be concentrated to the thick solution containing 180-260g/L hydrazine hydrate, cycles of concentration 1:0.5-0.7, is sent from scheming by the sodium-chlor of precipitation simultaneously and isolates solid sodium chloride;
(4) thick solution step (3) obtained is after being pre-chilled to 35-45 DEG C, send in crystallization kettle and carry out being cooled to 0 DEG C with chilled brine again--after-2 DEG C, the Sodium carbonate decahydrate of separating out is sent from scheming and isolates Sodium carbonate decahydrate xln, obtains the smart hydrazine liquid containing 210-230g/L hydrazine hydrate;
(5) by the smart hydrazine liquid repeating step (3) that obtains and step (4) repeatedly, until obtain the refined soln containing 40% hydrazine hydrate.
3. optimization Wyler's process according to claim 1 produces the technique of hydrazo-dicarbonamide, it is characterized in that: the method specifically comprises the steps:
(1) will be that 120-130 DEG C send into after precooling in crystallization kettle containing the thick solution of < 70g/L hydrazine hydrate carries out being cooled to 0 DEG C with chilled brine by hydrazine hydrate reactor temperature out--after-2 DEG C, the Sodium carbonate decahydrate of separating out is sent from the part Sodium carbonate decahydrate xln that crystallization is isolated in scheming, obtains the smart hydrazine liquid containing 50-75g/L hydrazine hydrate;
(2) the smart hydrazine liquid that step (1) obtains is sent in vaporizer after preheating, carry out evaporation concentration under vacuum to the thick solution containing 75-160g/L hydrazine hydrate, cycles of concentration 1:0.5-0.7, is sent from scheming by the sodium-chlor of precipitation simultaneously and isolates solid sodium chloride;
(3) the thick solution obtained by step (2) is after being pre-chilled to 35-45 DEG C, send in crystallization kettle and carry out being cooled to 0 DEG C with chilled brine--after-2 DEG C, the Sodium carbonate decahydrate of separating out is sent from scheming and isolates Sodium carbonate decahydrate xln, obtains the smart hydrazine liquid containing 90-200g/L hydrazine hydrate;
(4) the smart hydrazine liquid that step (3) obtains is sent in another vaporizer again evaporate, be concentrated to the thick solution containing 160-250g/L hydrazine hydrate, cycles of concentration 1:0.5-0.7, is sent from scheming by the sodium-chlor of precipitation simultaneously and isolates solid sodium chloride;
(5) thick solution step (4) obtained is after being pre-chilled to 35-45 DEG C, send in crystallization kettle and carry out being cooled to 0 DEG C with chilled brine--after-2 DEG C, the Sodium carbonate decahydrate of separating out is sent from scheming and isolates Sodium carbonate decahydrate xln, obtains the smart hydrazine liquid containing 180-300g/L hydrazine hydrate;
(6) smart hydrazine liquid repeating step (4) and step (5) will be obtained repeatedly, until obtain the refined soln containing 40% hydrazine hydrate.
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| CN105859592A (en) * | 2016-06-23 | 2016-08-17 | 青海盐湖工业股份有限公司 | Method for recycling coproduct hydrochloric acid in ADC (azodicarbonamide) foaming agent preparation process |
| CN105924666A (en) * | 2016-04-15 | 2016-09-07 | 佛山市聚成生化技术研发有限公司 | Efficient foaming agent and preparation method thereof |
| CN106349119A (en) * | 2016-08-26 | 2017-01-25 | 衡阳市锦轩化工有限公司 | Method for co-production of biurea and sodium fluoride |
| CN107055581A (en) * | 2017-03-31 | 2017-08-18 | 衡阳市锦轩化工有限公司 | A kind of method of coproduction hexafluoro sodium aluminate and biruea |
| CN110775950A (en) * | 2019-11-21 | 2020-02-11 | 江苏索普化工股份有限公司 | Method for recovering and refining saline-alkali from high-salt hydrazine hydrate solution |
| CN112250049A (en) * | 2020-09-24 | 2021-01-22 | 江苏索普化工股份有限公司 | Method for separating saline and alkaline byproduct of hydrazine hydrate by urea method |
| CN112479221A (en) * | 2020-12-21 | 2021-03-12 | 河北昊德生物科技有限公司 | Production and synthesis process of sodium octaborate tetrahydrate |
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN105924666A (en) * | 2016-04-15 | 2016-09-07 | 佛山市聚成生化技术研发有限公司 | Efficient foaming agent and preparation method thereof |
| CN105859592A (en) * | 2016-06-23 | 2016-08-17 | 青海盐湖工业股份有限公司 | Method for recycling coproduct hydrochloric acid in ADC (azodicarbonamide) foaming agent preparation process |
| CN106349119A (en) * | 2016-08-26 | 2017-01-25 | 衡阳市锦轩化工有限公司 | Method for co-production of biurea and sodium fluoride |
| CN106349119B (en) * | 2016-08-26 | 2018-08-03 | 衡阳市锦轩化工有限公司 | The method of coproduction biruea and sodium fluoride |
| CN107055581A (en) * | 2017-03-31 | 2017-08-18 | 衡阳市锦轩化工有限公司 | A kind of method of coproduction hexafluoro sodium aluminate and biruea |
| CN110775950A (en) * | 2019-11-21 | 2020-02-11 | 江苏索普化工股份有限公司 | Method for recovering and refining saline-alkali from high-salt hydrazine hydrate solution |
| CN112250049A (en) * | 2020-09-24 | 2021-01-22 | 江苏索普化工股份有限公司 | Method for separating saline and alkaline byproduct of hydrazine hydrate by urea method |
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Application publication date: 20150909 |