CN103864676A - Methods for improving production process of paraquat and obtaining crystals - Google Patents
Methods for improving production process of paraquat and obtaining crystals Download PDFInfo
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- CN103864676A CN103864676A CN201210567365.3A CN201210567365A CN103864676A CN 103864676 A CN103864676 A CN 103864676A CN 201210567365 A CN201210567365 A CN 201210567365A CN 103864676 A CN103864676 A CN 103864676A
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D213/00—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members
- C07D213/02—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members
- C07D213/04—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom
- C07D213/06—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom containing only hydrogen and carbon atoms in addition to the ring nitrogen atom
- C07D213/22—Heterocyclic compounds containing six-membered rings, not condensed with other rings, with one nitrogen atom as the only ring hetero atom and three or more double bonds between ring members or between ring members and non-ring members having three double bonds between ring members or between ring members and non-ring members having no bond between the ring nitrogen atom and a non-ring member or having only hydrogen or carbon atoms directly attached to the ring nitrogen atom containing only hydrogen and carbon atoms in addition to the ring nitrogen atom containing two or more pyridine rings directly linked together, e.g. bipyridyl
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- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
- A01N43/00—Biocides, pest repellants or attractants, or plant growth regulators containing heterocyclic compounds
- A01N43/34—Biocides, pest repellants or attractants, or plant growth regulators containing heterocyclic compounds having rings with one nitrogen atom as the only ring hetero atom
- A01N43/40—Biocides, pest repellants or attractants, or plant growth regulators containing heterocyclic compounds having rings with one nitrogen atom as the only ring hetero atom six-membered rings
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- Agronomy & Crop Science (AREA)
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Abstract
The invention relates to methods for improving a synthetic production process of a herbicide and obtaining crystals and particularly relates to methods for improving the synthetic process of a paraquat herbicide and obtaining paraquat crystals (wet products). According to the methods, by mainly controlling a dehydration crystallization process of a paraquat solution, the problem that a paraquat raw medicament or the crystal is difficult to obtain due to the high solubility of the paraquat raw medicament in water is solved.
Description
Technical field
The present invention relates to a kind of method that improvement of weedicide synthesis technique and xln obtain, particularly the synthetic process modification of a kind of Paraquat weedicide and the preparation method of Paraquat xln (wet product).
Background technology
Paraquat is second largest kind in weedicide in the world, and annual global marketing volume is more than 1,000,000,000 dollars.At home, the output of Paraquat occupies second, but is first weedicide kind by domestic consumption, and its output and demand increase year by year, and market competition is also very strong.
Paraquat is produced two kinds of sodium method and ammonia cyanogen methods, and sodium method is because yield is low, and the dangerous defect such as large of technique, substantially superseded.Obtain after important breakthrough in ammonia cyanogen method production technique, domestic enterprise generally adopts ammonia cyanogen method.In ammonia cyanogen method production technique, generally first obtain intermediate 1,1 '-dimethyl-4,4 '-dihydro dipyridyl, in its aqueous solution, pass into chlorine again, reaction obtains the synthetic liquid of Paraquat (Paraquat two villaumite weight percents are), and this step total recovery is generally 95% at present, add after stink agent, emetic, obtain the female medicine of Paraquat after meeting national standard etc.Intermediate 1,1 '-dimethyl-4, the equation that 4 '-dihydro dipyridyl and chlorine reaction are produced Paraquat is:
At present, the former medicine of Paraquat still former capital is the female medicine of liquid, and degree is 42% (in Paraquat two villaumites) substantially, there is no the former medicine registration of Paraquat solid and sells.The female medicine of Paraquat liquid, thus many-sided inconveniences such as packaging, transport and storage brought owing to comprising a large amount of aqueous solvent, increased cost simultaneously.Along with development and the needs in market, particularly carrying out of the Paraquat restricted control measures of substep, Paraquat aqua will rise and stop selling at home and using on July 1st, 2016, this has brought opportunity to exploitation of Paraquat solid and colloid formulation, more and more urgent to obtaining the technical need of the former medicine of high-content Paraquat solid.
In actual production, Paraquat is difficult to crystallization and obtains the former medicine of high content of solid, and its major cause is that Paraquat solubleness in water is larger, and its soltion viscosity is very large, has increased its crystallization difficulty.
In order to solve the difficult problem of this crystallization, Chinese patent application 99119405.5 discloses a kind of taking the female medicine of Paraquat liquid as raw material, obtain the method for the former medicine of Paraquat solid by decompression, oven dry and pulverizing, but the method complex process, energy consumption are large, dry the waste gas or the waste water that produce and can carry a small amount of Paraquat, need to further process, increased production cost, the Paraquat powder that disintegrating process and pulverizing obtain, very easily produces and pollutes and human body is produced to harm.
In addition, be difficult at present find a kind of organic solvent of routine can from its system, extract the good solid of form.Therefore, be badly in need of addressing the above problem, to meet the demand of market development.
Summary of the invention
For above problems and shortcomings, the invention provides improving one's methods of the former medicine of a kind of Paraquat solid.
The technical solution used in the present invention is: Paraquat is synthesized to liquid or female medicine or Paraquat solution by the method for dehydration, obtain certain density Paraquat solution, then obtain Paraquat solid wet product and Paraquat mother liquor by crystallization, separation.Described Paraquat solution (taking Paraquat two villaumite weight percent meters) concentration is as 1-45%.
Paraquat solution dehydrates method described in the present invention comprises: the intensification thickening of decompression/normal pressure, bringing Selection In property water-retaining agent dewater, add the one or more combinations such as the heating azeotropic dehydration of organic solvent.
Wherein selectivity water-retaining agent comprises one or more of the high molecular polymerization water-retaining agents such as molecular sieve, gac, water-absorbing resin.Organic solvent comprise methyl alcohol, ethanol, acetone, toluene, dimethylbenzene, Virahol etc. one or more.
Because the Paraquat strength of solution obtaining is most important on the impact of crystallization, therefore in order effectively to obtain Paraquat xln (wet product), must strictly control dehydrating amount.As dehydrating amount very little, temperature reduce after, crystallizing system can not reach the saturation concentration of Paraquat, will cause does not have crystal to separate out; And dehydrating amount is too many, will cause Paraquat excessive concentration in crystallizing system, crystallized product is pulpous state, and the serious block that also can be bonded to, can not directly obtain Paraquat xln (wet product).
In the present invention, dehydration is strictly controlled dehydrating amount, and making the Paraquat strength of solution weight percent obtaining is 50%～80% (in Paraquat two villaumites), and preferably 55%～65%.
In the present invention, concentrated if the method for dehydration adopts decompression to heat up, thickening temperature should be controlled at more than 50 DEG C, preferably more than 60 DEG C.Thickening temperature is too low, in the time being concentrated to finite concentration, easily occurs too much thin crystalline substance in concentrated solution, and viscosity of sludge can be very large simultaneously, and when these are all unfavorable for crystallization, crystal grows up.
Crystallization described in the present invention comprises decrease temperature crystalline and condensing crystal.The condition such as control and stirring of rate of temperature fall, concentrated speed, thickening temperature all has very important impact to crystallisation process.
In the present invention, when decrease temperature crystalline, rate of temperature fall should be controlled at 2～20 DEG C/h, preferably 3～10 DEG C/h.Rate of temperature fall is too fast, can make that crystal is too fast separates out, and causes crystal grain meticulous, and when serious, crystal is clamminess, thereby crystal cannot separate smoothly.
In the present invention, when condensing crystal, after crystal occurs, concentrated speed should be controlled at concentrated solution concentration per hour increases by 1～10%, and preferably 2～7%.Concentrated speed is too fast, can make that crystal is too fast separates out, and causes crystal grain meticulous, and when serious, crystal is clamminess, thereby crystal cannot separate smoothly.
In the present invention, when condensing crystal, after crystal occurs, thickening temperature should be controlled at more than 70 DEG C, and thickening temperature is too low, causes when concentrated viscosity of sludge excessive, easy to foaming, is unfavorable for growing up of crystal.
It is necessary in the present invention, carrying out continuously stirring, but in the time of crystallization, should control stirring velocity at 20～500 revs/min, preferably 30～300 revs/min.Stirring velocity is too fast, can cause crystal meticulous, and when serious, crystal is clamminess, and affects later stage separation and crystal quality; Stirring velocity is excessively slow, crystal can not Effective Suspension in crystallizing system, be unfavorable for growing up of crystal.
Described in the present invention, scheme comprises, by the synthetic liquid of Paraquat or female medicine intensification thickening, control dehydrating amount, after dehydration, Paraquat weight percent is 50-80%, preferably 55-65%, cooling crystallization, control rate of temperature fall at 2～20 DEG C/h, preferably 3～10 DEG C/h, crystallization control stirring velocity 20-500 rev/min, preferably 30-300 rev/min, slowly obtains Paraquat crystallization wet product or solution.
Described Paraquat crystallization wet product, adding the filler crushing to mix becomes solid, adds after the national regulation auxiliary agents such as tensio-active agent, emetic, stink agent, through granulation or compressing tablet post-drying, makes solid preparation.
Further comprise after adding solid adsorbent absorption and add the filler and the auxiliary agent etc. that crush, make solid preparation.
Described solid adsorbent includes but not limited to one or more in white carbon black, activated alumina, soluble resin, inorganic salt etc.; Inorganic salt sorbent material comprises one or more in pyrophosphate salt, poly-phosphate, vitriol, phosphoric acid salt, phosphite and inorganic compounding salt etc.
The present invention also comprises a kind of improvement preparation method of synthesizing paraquat by ammoniacal cyanide process.Owing to containing certain density Paraquat in concentrated waste water and mother liquor, in mother liquor, also contain in addition a small amount of 1,1 '-dimethyl-4,4 '-dihydro dipyridyl, has brought very large difficulty to wastewater treatment.
The present invention originates as moisture by Paraquat being synthesized to the Paraquat mother liquor that obtains obtaining after concentrated waste water and Crystallization Separation after the female medicine of liquid or liquid concentrates, add inward people a certain amount of 1,1 '-dimethyl-4,4 '-dihydro dipyridyl, after stirring and dissolving, pass into chlorine, reaction obtains the synthetic liquid of Paraquat.Service water consumption and wastewater treatment capacity are greatly reduced like this, in mother liquor, do not get transformed on a small quantity 1 of Paraquat simultaneously, 1 '-dimethyl-4,4 '-dihydro dipyridyl raw material is by applying mechanically, transform for Paraquat, improve the yield of Paraquat, made this step Paraquat total recovery bring up to 97%～98% by common 95%.
Advantage of the present invention is:
1, because Paraquat crystallization difficulty is large, also do not have on the market at present the former medicine of Paraquat solid to sell, only have the female medicine of Paraquat liquid and Paraquat aqua.The present invention, by changing precipitation and the 4 Crystallization of the synthetic liquid of Paraquat or the female medicine of liquid, has obtained Paraquat crystal (wet product), has solved the problem of Paraquat crystallization difficulty, is convenient to the exploitation of Paraquat solid dosage.
2, will separate concentrated waste water and the mother liquor that Paraquat crystal (wet product) produces, alternative water source is recovered in the synthesis technique of Paraquat, improve the yield of Paraquat, reduced service water consumption and wastewater treatment capacity simultaneously, reduced the production cost of Paraquat.
Specific implementation method
Embodiment
Following examples only, in order to the object of explanation, do not limit the scope of the invention, and these embodiment contribute to better to understand the present invention, understand the variation of its advantage and some skills.
Embodiment 1:
In the 2L reactor of band stirring and refrigerating unit, add the female medicine of Paraquat liquid of 1000g42% (in Paraquat two villaumites), under condition of normal pressure, heating concentrates, and striking point temperature is 120 DEG C, concentrates out the concentrated waste water of 350g, decrease temperature crystalline, while cooling to 55 DEG C, controlling rate of temperature fall is 10 DEG C/h, and stir speed (S.S.) is 300 revs/min, be cooled to 20 DEG C of filtrations, obtain 430.2g Paraquat crystal and 219.8g Paraquat mother liquor.Analyzing Paraquat crystalline content is 79.9% (in Paraquat two villaumites), and Paraquat mother liquor Paraquat content is 34.7%.
Embodiment 2:
In the reactor of 2L, add the female medicine of Paraquat liquid of 1000g42% (in Paraquat two villaumites), be warming up to 100 DEG C, add 5g selectivity water suction molecular sieve, filtered while hot after 20 minutes, filtration obtains 600.3g Paraquat solution, put it in the 1L reactor of band stirring and refrigerating unit, decrease temperature crystalline, while cooling to 75 DEG C, controlling rate of temperature fall is 9 DEG C/h, and stir speed (S.S.) is 280 revs/min, be cooled to 30 DEG C of filtrations, obtain 480.8g Paraquat crystal and 119.5g Paraquat mother liquor.Analyzing Paraquat crystalline content is 81.2% (in Paraquat two villaumites).
Embodiment 3:
In the 2L reactor of band stirring and refrigerating unit, add the female medicine of Paraquat liquid of 1000g42% (in Paraquat two villaumites), be under 0.05mPa in vacuum tightness, heating is concentrated, concentrates out after the concentrated waste water of 200g, temperature is 60 DEG C, now have a small amount of crystal to separate out, controlling concentrated speed is 55g/h, and stir speed (S.S.) is 280 revs/min, concentrate out filtered while hot after the concentrated waste water of 275g, obtain 391g Paraquat crystal and 134g Paraquat mother liquor.Analyzing Paraquat crystalline content is 90% (in Paraquat two villaumites).
Embodiment 4:
In the 2L reactor of band stirring and refrigerating unit, add the synthetic liquid of Paraquat and the 500g toluene of 1000g43.5% (in Paraquat two villaumites), under condition of normal pressure, heating is concentrated, concentrate out the concentrated waste water of 800g, decrease temperature crystalline, while cooling to 80 DEG C, controlling rate of temperature fall is 5 DEG C/h, stir speed (S.S.) is 200 revs/min, is cooled to 30 DEG C of filtrations, obtains 298.2g Paraquat crystal and 401.8g Paraquat mother liquor.Analyzing Paraquat crystalline content is 92% (in Paraquat two villaumites).
Embodiment 5:
In the 2L reactor of band stirring and refrigerating unit, add the synthetic liquid of Paraquat and the 300g methyl alcohol of 1000g44% (in Paraquat two villaumites), under condition of normal pressure, heating is concentrated, concentrate out after the concentrated waste water of 650g, temperature is 90 DEG C, now has a small amount of crystal to separate out, controlling concentrated speed is 55g/h, stir speed (S.S.) is 280 revs/min, concentrates out filtered while hot after the concentrated waste water of 100g, obtains 348g Paraquat crystal and 202g Paraquat mother liquor.Analyzing Paraquat crystalline content is 89% (in Paraquat two villaumites).
Embodiment 6:
In the reactor of 2L, add the synthetic liquid of Paraquat of 1000g45% (in Paraquat two villaumites), be warming up to 100 DEG C, add 5g selectivity water suction molecular sieve, filtered while hot after 20 minutes, filtration obtains 605.5g Paraquat solution, put it in the 1L reactor of band stirring and refrigerating unit, decrease temperature crystalline, while cooling to 75 DEG C, controlling rate of temperature fall is 8 DEG C/h, and stir speed (S.S.) is 270 revs/min, be cooled to 30 DEG C of filtrations, obtain 485.3g Paraquat crystal and 120.2g Paraquat mother liquor.Analyzing Paraquat crystalline content is 81.3% (in Paraquat two villaumites).
: embodiment 7:
The concentrated waste water of 219.8g Paraquat mother liquor, 350g that 73g service water and embodiment 1 are obtained join that band stirs and the 2L reactor of refrigerating unit in, add 255g1,1 '-dimethyl-4,4 '-dihydro dipyridyl, open and stir, at 40 DEG C, pass into chlorine, process on-line monitoring pH value, reach at 4 o'clock until pH value and be reaction end, obtain the synthetic liquid of Paraquat.Weight is 1000g, and content is 42% (in Paraquat two villaumites), and Paraquat yield is 97.5%.
By synthetic this 1000g Paraquat liquid, join in the 2L reactor of band stirring and refrigerating unit, under reduced pressure, heating concentrates, and striking point temperature is 80 DEG C, concentrates out the concentrated waste water of 350g, decrease temperature crystalline, while cooling to 55 DEG C, controlling rate of temperature fall is 10 DEG C/h, and stir speed (S.S.) is 300 revs/min, be cooled to 20 DEG C of filtrations, obtain 422.4g Paraquat crystal and 227.6g Paraquat mother liquor.Analyzing Paraquat crystalline content is 80.2% (in Paraquat two villaumites), and Paraquat mother liquor content is 35.7%.
Embodiment 8:
The concentrated waste water of 227.6g Paraquat mother liquor, 350g that 73g service water and embodiment 7 are obtained join that band stirs and the 2L reactor of refrigerating unit in, add 255g1,1 '-dimethyl-4,4 '-dihydro dipyridyl, open and stir, at 40 DEG C, pass into chlorine, process on-line monitoring pH value, reach at 4 o'clock until pH value and be reaction end, obtain the synthetic liquid of Paraquat.Weight is 1020.6g, and content is 41.7% (in Paraquat two villaumites), and Paraquat yield is 97.8%.
Synthetic this Paraquat liquid is joined in the 2L reactor of band stirring and refrigerating unit, under reduced pressure, heating is concentrated, striking point temperature is 80 DEG C, concentrate out the concentrated waste water of 361.8g, decrease temperature crystalline, while cooling to 55 DEG C, controlling rate of temperature fall is 10 DEG C/h, stir speed (S.S.) is 300 revs/min, is cooled to 20 DEG C of filtrations, obtains 435.3g Paraquat crystal and 223.5g Paraquat mother liquor.Analyzing Paraquat crystalline content is 80.1% (in Paraquat two villaumites), and Paraquat mother liquor content is 34.5%.
Claims (10)
1. the improvement preparation method of the former medicine of Paraquat solid, it is characterized in that the synthetic liquid with paraquat produced by cyanamideprocess or the female medicine of Paraquat or Paraquat solution, through dewater to Paraquat weight percent be 50-80%, preferably 55-65%, crystallization, crystallization control stirring velocity 20-500 rev/min, preferably 30-300 rev/min, separates and obtains Paraquat solid crystal wet product and Paraquat mother liquor.
2. the method for claim 1, is characterized in that described dehydration, comprises one or more combinations such as decompression/normal pressure intensification thickening, the dehydration of selectivity water-retaining agent, organic solvent heating azeotropic dehydration.
3. method as claimed in claim 2, is characterized in that described selectivity water-retaining agent comprises one or more combinations of the high molecular polymerization water-retaining agents such as molecular sieve, gac, water-absorbing resin.
4. method as claimed in claim 2, is characterized in that described organic solvent comprises one or more combinations in methyl alcohol, ethanol, acetone, toluene, dimethylbenzene, Virahol etc.
5. method as claimed in claim 2, is characterized in that described decompression heats up concentrated, controls dehydration temperaturre and is greater than 50 DEG C, is preferably greater than 60 DEG C.
6. the method for claim 1, is characterized in that described crystallization comprises decrease temperature crystalline and or condensing crystal.
7. method as claimed in claim 6, while it is characterized in that adopting decrease temperature crystalline, controls rate of temperature fall at 2-20 DEG C/h, preferably 3-10 DEG C/h; While adopting condensing crystal, controlling concentrated speed is that concentrated solution percentage concentration per hour increases 1-10%, preferably 2-7%, and thickening temperature control is greater than 70 DEG C.
8. the method for claim 1, it is characterized in that synthetic Paraquat liquid or female medicine by intensification thickening, controlling dehydrating amount to Paraquat weight percent is 50-80%, preferably 55-65%, then cools, and controls rate of temperature fall at 2～20 DEG C/h, preferably 3～10 DEG C/h, crystallization control stirring velocity 20-500 rev/min, preferably 30-300 rev/min, slowly obtains Paraquat crystallization wet product or solution.
9. the method for claim 1, is characterized in that further adding filler to mix Paraquat crystallization wet product, adds tensio-active agent, emetic, stink agent etc., through granulation or compressing tablet post-drying, makes Paraquat solid preparation.
10. an ammonia cyanogen legal system is improved one's methods for the production of Paraquat, it is characterized in that the concentrated waste water and the mother liquor that produce separating Paraquat crystal (wet product), Substitute For Partial water source, add 1 of calculated amount, 1 '-dimethyl-4,4 '-dihydro dipyridyl, passes into chlorine after stirring and dissolving, reaction obtains the synthetic liquid of Paraquat.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105348175A (en) * | 2015-12-23 | 2016-02-24 | 山东胜邦绿野化学有限公司 | Paraquat purification method |
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| CN1247026A (en) * | 1999-09-21 | 2000-03-15 | 尹智铉 | Solid or semi-solid parataf preparation and its preparing method |
| CN101628890A (en) * | 2009-08-14 | 2010-01-20 | 山东省农药研究所 | Method for synthesizing paraquat by ammoniacal cyanide process |
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2012
- 2012-12-15 CN CN201210567365.3A patent/CN103864676A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN1247026A (en) * | 1999-09-21 | 2000-03-15 | 尹智铉 | Solid or semi-solid parataf preparation and its preparing method |
| CN101628890A (en) * | 2009-08-14 | 2010-01-20 | 山东省农药研究所 | Method for synthesizing paraquat by ammoniacal cyanide process |
Non-Patent Citations (1)
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN105348175A (en) * | 2015-12-23 | 2016-02-24 | 山东胜邦绿野化学有限公司 | Paraquat purification method |
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