CN107245057A - The Joint Production of pentamethylol melamine and hexamethylolmelamine - Google Patents
The Joint Production of pentamethylol melamine and hexamethylolmelamine Download PDFInfo
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- CN107245057A CN107245057A CN201710696029.1A CN201710696029A CN107245057A CN 107245057 A CN107245057 A CN 107245057A CN 201710696029 A CN201710696029 A CN 201710696029A CN 107245057 A CN107245057 A CN 107245057A
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- melamine
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D251/00—Heterocyclic compounds containing 1,3,5-triazine rings
- C07D251/02—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings
- C07D251/12—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members
- C07D251/26—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members with only hetero atoms directly attached to ring carbon atoms
- C07D251/40—Nitrogen atoms
- C07D251/54—Three nitrogen atoms
- C07D251/64—Condensation products of melamine with aldehydes; Derivatives thereof
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Abstract
The Joint Production of pentamethylol melamine and hexamethylolmelamine, including：Melamine, formaldehyde and water input five is hydroxylated in reactor according to stoichiometric proportion；Reactant is centrifuged, waste water is sloughed and finished product pentamethylol melamine is obtained after drying；A part for above-mentioned waste water is returned to five and is hydroxylated reactor to carry out duplication of production, remainder is introduced six hydroxylation reaction kettles as partial mother liquid to produce hexamethylolmelamine.According to the joint production process of the present invention so that pentahydroxy- waste water and six hydroxyl waste water can be used for circulating coproduction, so that the production cost of the production cost, especially pentahydroxy- product of pentahydroxy- product and six hydroxyl products is considerably reduced, while realizing no pollution discharge.
Description
Technical field
The present invention relates to pentamethylol melamine and the combined producing process of hexamethylolmelamine.
Background technology
Pentamethylol melamine can be used as producing the raw material of the high imino-type etherified amino resins of Multiple Type, but it is given birth to
Produce cost height and environmental pollution is serious.
The content of the invention
It is an object of the invention to provide the joint production process of a kind of pentamethylol melamine and hexamethylolmelamine or
Method, it can overcome above mentioned problem.
According to the pentamethylol melamine of the present invention and the combined producing process of hexamethylolmelamine, including：
1.1) according to melamine: formaldehyde: water mol ratio is 1: (4.5~6.0): (8~20) are into five hydroxylation reactors
Feed intake, the process of feeding intake is：The water of above-mentioned metering is first added into reactor；Adjust reactor agitator rotating speed be 60~120 turns/
Minute, the formaldehyde of above-mentioned metering is added, formaldehyde used is the formalin of mass fraction 40% or so；Plus alkali regulation pH value
To 8.0 or so, adjust temperature to add the melamine of above-mentioned metering after 25~50 DEG C；40 are warming up to after 20~50min of stirring
~75 DEG C, pH is kept to be 8.0 or so with alkali again；
1.2) after melamine is completely dissolved reduce reactor mixing speed, regulation agitator speed be 30~90 turns/
Minute, react 1~4h；
1.3) stop stirring, stand 1~3h of crystallization, centrifuge, slough waste water, be drying to obtain the methylol trimerization of finished product five
Cyanamide；
1.4) using step 1.3) wastewater produced at least a portion introduce six hydroxylation reaction kettles as partial mother liquid and after
It is continuous to perform following processing steps：
2.1) mother liquor or water are added in six hydroxylation reaction kettles；
2.2) add formalin in a kettle. again, and cause content of formaldehyde to remain 10%~25%；
2.3) stirring and heating kettle in solution to 40~80 DEG C；
2.4) alkali is added into reactor, solution ph is between 8.5 to 9.5 in preconditioning kettle；
2.5) melamine and then into reactor is added so that the mol ratio of melamine and formaldehyde is 1：6~15；
2.6) alkali is added again into reactor, solution ph is between 8.5 to 10.0 in regulation kettle；
2.7) reaction solution temperature in kettle is risen to 60~85 DEG C, and is incubated 1~4 hour；
2.8) it is introduced into centrifuge after solution in kettle is cooled to below 40 DEG C to be centrifuged, obtains hexamethylol
Melamine wet feed and mother liquor；
2.9) hexamethylolmelamine wet feed is sent into drying system to carry out subsequently being dried to obtain finished product hexamethylol three
Poly cyanamid；
2.10) mother liquor is returned in reactor；And
Repeat the above steps 2.1) to 2.10) circulation production hexamethylolmelamine,
Wherein step 2.2) in the formalin that is added to be prepared in situ and concentration is higher than 55%.
According to a particular embodiment of the invention, wherein in step 1.4) in a wastewater produced part can also be returned
Five hydroxylation reactors.In addition, in the case of discontinuous batch production even stopping production pentamethylol melamine, will can also give up
Water all be used for produce hexamethylolmelamine without discharge cause environmental pollution.
According to a particular embodiment of the invention, wherein in step 1.1) in can use sodium hydroxide, potassium carbonate or sodium carbonate
It is used as alkali.
According to a particular embodiment of the invention, wherein in step 1.1) in agitator speed can be 80~100 revs/min
Clock, in step 1.2) in agitator speed can be 50~70 revs/min.
According to a preferred embodiment of the invention, in step 1.1) in can adjust temperature and rear add above-mentioned meters for 45 DEG C or so
The melamine of amount；55 DEG C or so are warming up to after stirring 30min or so.
According to the present invention each preferred embodiment, step 2.2) in content of formaldehyde be preferably maintained at 20% or so；Step
2.3) temperature in is preferably 50 DEG C~70 DEG C, more preferably 60 DEG C or so；Step 2.3) in pH value be preferably 9.0 or so；
Step 2.5) in mol ratio be preferably 1：8~10, more preferably 1：8.5 left and right；Step 2.6) in pH value be preferably 9.0
Left and right；Step 2.7) in, temperature is preferably 80 DEG C or so, and is preferably incubated 3 hours or so.
High concentration formaldehyde solution concentration according to prepared by the present invention is preferably 58%.
According to one embodiment of present invention, wherein reactor is arranged on centrifuge, step 2.9) in come from centrifugation
The mother liquor of machine is pumped back in reactor.
According to a preferred embodiment of the invention, the process that is prepared in situ of high concentration formaldehyde solution includes：
Methanol and air are passed through evaporator；
The gas and dispensing steam that go out flash-pot are imported into superheater together；
The gas for coming from superheater is passed through into fire-retardant filter；
The gas for coming from fire-retardant filter is imported into oxidator；
The formaldehyde gas for coming from oxidator is imported into the first spray column；
The formaldehyde gas for coming from the first spray column is imported into the second spray column；
The formaldehyde gas for coming from the second spray column is imported into the 3rd spray column；And
The formaldehyde tail gas for coming from the 3rd spray column is imported into tail gas boiler,
External shower water wherein is imported from the tower top of the 3rd spray column, is imported from the tower top of the second spray column from the 3rd spray
The absorption water of the bottom of towe of tower, and the absorption water of bottom of towe of the tower top importing from the second spray column from the first spray column are drenched,
The absorption water of the bottom of towe of first spray column is circulated the tower top that is pumped to the first spray column to be made as circulated sprinkling water
With, until discharged it after reaching predetermined formalin concentration,
The absorption water of the bottom of towe of second spray column is circulated the tower top that is pumped to the second spray column to be made as circulated sprinkling water
With, and the tower top of the first spray column is pumped into after repeatedly circulation,
The absorption water of the bottom of towe of 3rd spray column is circulated the tower top that is pumped to the 3rd spray column to be made as circulated sprinkling water
With, and it is discharged into the tower top of the second spray column after repeatedly circulation.
According to a preferred embodiment of the present invention, wherein preparing dispensing steam using the heat produced by tail gas boiler.
According to the joint production process of the present invention so that pentahydroxy- waste water and six hydroxyl waste water (or also referred to as " mother liquor ") can be by
For circulating production, so as to considerably reduce production cost (the especially life of pentahydroxy- product of pentahydroxy- product and six hydroxyl products
Produce cost), while realizing no pollution discharge.In addition, according to the joint production process of the present invention, the production of pentamethylol melamine
Conversion ratio can be up to 85% (in terms of melamine), and the production conversion ratio of hexamethylolmelamine even can be up to 90%
(in terms of melamine).
Embodiment
The present invention is described in detail with reference to specific embodiment.
Embodiment 1
1.1) according to melamine: formaldehyde: water mol ratio feeds intake for 1: 4.5: 10 into five hydroxylation reactors.First to reaction
The water of above-mentioned metering is added in kettle；It is 70 revs/min to adjust reactor agitator rotating speed, adds the formaldehyde of above-mentioned metering, institute
With the formalin that formaldehyde is mass fraction 37%；Plus 30% sodium hydrate aqueous solution adjust pH value to 8.0, regulation temperature is
The melamine of above-mentioned metering is added after 30 DEG C；45 DEG C are warming up to after stirring 30min, is protected again with 30% sodium hydrate aqueous solution
It is 8.0 to hold pH；
1.2) reactor mixing speed is reduced after melamine is completely dissolved, regulation agitator speed is 50 revs/min,
Keep reaction 3h；
1.3) stop stirring, stand crystallization 1h, centrifuge, slough waste water, be drying to obtain the methylol melamine of finished product five
Amine, it is white granular solid, and conversion ratio is 70% (in terms of melamine)；
1.4) by step 1.3) wastewater produced 1/3rd return to five and be hydroxylated reactors and repeat the above steps 1.1)
To 1.3)；Using step 1.3) wastewater produced remainder introduces six hydroxylation reaction kettles as part (circulation) mother liquor and performs
The production technology of following hexamethylolmelamines, its generally include in six hydroxylation reaction kettles add formaldehyde, melamine with
And alkali is reacted, centrifuge and product is obtained after drying and is packed.Waste gas produced by centrifugation and drying process leads to
Exhaust gas treating tower carries out subsequent treatment.The mother liquor centrifuged out is recycled as raw materials for production again in whole process, specifically
Cycle production process is as follows：
2.1) (circulation) mother liquor or water are added in six hydroxylation reaction kettles；
2.2) add formalin in a kettle. again so that content of formaldehyde remains 10%~25%, be preferably
15%~20%；
2.3) stir and solution is to 40~80 DEG C in heating kettle, preferably 50 DEG C~70 DEG C, more preferably 60 DEG C or so：
The temperature range will not both make formaldehyde excessively volatilize, and melamine can be quickly dissolved again；
2.4) into reactor add alkali such as sodium hydroxide solution, preconditioning kettle in solution ph be 8.5 to 9.5 it
Between, preferably 9.0 or so：Precondition pH value very crucial, it can accurately control reactive chemistry metering ratio in subsequent step
And the decline of extent of reaction, in addition pH value selection pH value when 9.0 or so can be adapted to follow-up addition melamine well, make
Alkali addition when obtaining Secondary Control is very small consequently facilitating regulation and control；
2.5) melamine and then into reactor is added so that the mol ratio of melamine and formaldehyde is 1：6~15, it is excellent
Elect 1 as：8~10, more preferably 1：8.5 left and right；
2.6) add alkali (sodium hydroxide solution) again into reactor, in regulation kettle solution ph be 8.5 to 10.0 it
Between, preferably 9.0 or so：Secondary Control keeps basically identical with preregulated pH value；
2.7) reaction solution temperature in kettle is risen to 60~85 DEG C such as 80 DEG C, and is incubated such as 3 hours 1~4 hour left sides
It is right；
2.8) it is introduced into centrifuge after solution in kettle is cooled to below 40 DEG C to be centrifuged, obtains hexamethylol
Melamine wet feed and (circulation) mother liquor：Reactor can be arranged on centrifuge, so that reaction product relies on gravity certainly
The dynamic centrifuge that flows into is separated, and the mother liquor after separation can be pumped back in reactor；
2.9) hexamethylolmelamine wet feed is sent into drying system to carry out subsequently drying (and packaging)；
2.10) (circulation) mother liquor (pumping) is returned in reactor；And
Repeat the above steps 2.2) to 2.10) progress circulation production.
According to the present invention, in above-mentioned hexamethylolmelamine circulation production process, the formalin added is
It is prepared in situ and concentration is higher than 55%, preferably 56% to 60%, more preferably 58%.It is prepared in situ by automatic production line
Carry out, obtained high-concentration formaldehyde supplements the above-mentioned circulation production process of participation on the spot.High-concentration formaldehyde is used so that in volume
In up to 10 cubic metres of reactor, each material stoichiometric proportion during above-mentioned cycle production process still can be stably
Preset range is maintained, realizes using pentahydroxy- and six hydroxyl waste water or mother liquor to industrialize Joint Production hexamethylolmelamine
Possibility.
As an example, the high-concentration formaldehyde of the present invention is prepared in situ technique and can included：
Methanol is pumped into head tank by metering from measuring tank, then evaporator is flowed into from head tank；
In addition, air is also passed into evaporator, evaporator after water scrubber again after air cleaner by roots blower
Temperature is set between 60 DEG C to 70 DEG C；
On the one hand, the gas come out from evaporator is passed through superheater, and on the other hand, dispensing steam is after vapor filter
Superheater is also passed into, superheater temperature is set in 110 DEG C between 120 temperature；
The mixed gas come out from superheater enters oxidator after fire-retardant filter and carries out silver-colored catalytic reaction and generate
Formaldehyde gas；
The formaldehyde gas for coming from oxidator is imported into the first spray column；
The formaldehyde gas for coming from the first spray column is imported into the second spray column；
The formaldehyde gas for coming from the second spray column is imported into the 3rd spray column；And
The formaldehyde tail gas for coming from the 3rd spray column is imported into tail gas boiler.
External shower water is imported from the tower top of the 3rd spray column, shower water uses the soft water pumped from soft water pond, from second
The tower top of spray column imports the absorption water of the bottom of towe from the 3rd spray column, and is imported from the tower top of the first spray column from the
The absorption water of the bottom of towe of two spray columns.
Second spray column is set directly under the 3rd spray column so that the absorption water of the bottom of towe of the 3rd spray column can be according to
The tower top of the second spray column is automatically flowed into by gravity.This characteristics of compact layout and water pump can be saved.
The absorption water of the bottom of towe of first spray column is circulated the tower top that is pumped to the first spray column to be made as circulated sprinkling water
With until detection is exported to formaldehyde measuring tank after reaching predetermined formalin concentration, as high concentration used in the present invention
Formalin.
The tower top that the absorption water of the bottom of towe of second spray column is pumped to the second spray column is used as circulated sprinkling water, directly
The tower top of the first spray column is pumped into after to some circulate such as three times.
The absorption water of the bottom of towe of 3rd spray column is circulated the tower top that is pumped to the 3rd spray column to be made as circulated sprinkling water
With the tower top up to being discharged into the second spray column after some circulate such as three times.
In each spray column in addition to circulating pump is installed, it is additionally provided with plate type heat exchanger to reduce formaldehyde gas temperature and return
Receipts utilize heat.
The present invention absorbs formaldehyde gas step by step by three-level absorption tower, concentration of formaldehyde is improved step by step, so as to provide height
Up to 60% formalin, the upper limit of concentration of general formalin is breached so that hexamethylolmelamine of the invention
Circulation production is able to realization of industrialization, so as to considerably reduce production cost and realize no pollution discharge.
Embodiment 2
Above-mentioned steps 1.1) in, fed intake by melamine, formaldehyde and water mol ratio for 1: 5.5: 20 mol ratio.Wherein institute
It is 40% formalin with formaldehyde, alkali is replaced by 30% wet chemical, and other conditions are constant；
In above-mentioned steps 1.2) in, keep reacting 4h, it is other constant；
In above-mentioned steps 1.3) in, crystallization 3h is stood, finished product pentamethylol melamine white granular solid is obtained, converted
Rate is 80% (in terms of melamine)；
In above-mentioned steps 1.4) in, by above-mentioned steps 1.3) wastewater produced collect for producing hexamethylol melamine
Amine.
Embodiment 3
Above-mentioned steps 1.1) in, fed intake by melamine, formaldehyde and water mol ratio for 1: 6.0: 20 mol ratio.Wherein institute
It is 37% formalin with formaldehyde, alkali is replaced by 30% aqueous sodium carbonate, and other conditions are constant；
In above-mentioned steps 1.2) in, keep reacting 3.5h, it is other constant；
In above-mentioned steps 1.3) in, crystallization 2h is stood, finished product pentamethylol melamine white granular solid is obtained, converted
Rate is 85% (in terms of melamine)；
In above-mentioned steps 1.4) in, by above-mentioned steps 1.3) wastewater produced collect for producing hexamethylol melamine
Amine.
It will be appreciated by those skilled in the art that foregoing description is intended merely to more fully understand the present invention, it is not intended to this
Any limitation is made in invention.
Claims (5)
1. the combined producing process of a kind of pentamethylol melamine and hexamethylolmelamine, including：
1.1) according to melamine: formaldehyde: water mol ratio is 1: (4.5~6.0): (8~20) feed intake into five hydroxylation reactors,
The process of feeding intake is：The water of above-mentioned metering is first added into reactor；It is 60~120 revs/min to adjust reactor agitator rotating speed,
The formaldehyde of above-mentioned metering is added, formaldehyde used is the formalin of mass fraction 40% or so；Plus alkali adjusts pH value to 8.0
Left and right, adjusts temperature to add the melamine of above-mentioned metering after 25~50 DEG C；40~75 are warming up to after 20~50min of stirring
DEG C, keep pH to be 8.0 or so with alkali again；
1.2) reactor mixing speed is reduced after melamine is completely dissolved, regulation agitator speed is 30~90 revs/min,
React 1~4h；
1.3) stop stirring, stand 1~3h of crystallization, centrifuge, slough waste water, be drying to obtain the methylol melamine of finished product five
Amine；
1.4) using step 1.3) six hydroxylation reaction kettles are as partial mother liquid and continue to hold for wastewater produced at least a portion introducing
The following processing steps of row：
2.1) mother liquor or water are added in six hydroxylation reaction kettles；
2.2) add formalin in a kettle. again, and cause content of formaldehyde to remain 10%~25%；
2.3) stirring and heating kettle in solution to 40~80 DEG C；
2.4) alkali is added into reactor, solution ph is between 8.5 to 9.5 in preconditioning kettle；
2.5) melamine and then into reactor is added so that the mol ratio of melamine and formaldehyde is 1：6~15；
2.6) alkali is added again into reactor, solution ph is between 8.5 to 10.0 in regulation kettle；
2.7) reaction solution temperature in kettle is risen to 60~85 DEG C, and is incubated 1~4 hour；
2.8) it is introduced into centrifuge after solution in kettle is cooled to below 40 DEG C to be centrifuged, obtains hexamethylol trimerization
Cyanamide wet feed and mother liquor；
2.9) hexamethylolmelamine wet feed is sent into drying system to carry out subsequently being dried to obtain finished product hexamethylol melamine
Amine；
2.10) mother liquor is returned in reactor；And
Repeat the above steps 2.1) to 2.10) circulation production hexamethylolmelamine,
Wherein step 2.2) in the formalin that is added to be prepared in situ and concentration is higher than 55%.
2. production technology according to claim 1, wherein in step 1.4) in by step 1.3) wastewater produced one
Divide return five to be hydroxylated reactors and continue to participate in production pentamethylol melamine.
3. production technology according to claim 1, wherein in step 1.1) middle sodium hydroxide, potassium carbonate or sodium carbonate work
For alkali.
4. production technology according to claim 1, wherein in step 1.1) in agitator speed be 80~100 revs/min,
In step 1.2) in agitator speed be 50~70 revs/min.
5. production technology according to claim 1, wherein in step 1.1) in regulation temperature be in 45 DEG C or so rear additions
State the melamine of metering；55 DEG C or so are warming up to after stirring 30min or so.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201710696029.1A CN107245057B (en) | 2017-08-15 | 2017-08-15 | Combined production of pentamethylol melamine and hexamethylol melamine |
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| CN201710696029.1A CN107245057B (en) | 2017-08-15 | 2017-08-15 | Combined production of pentamethylol melamine and hexamethylol melamine |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108440432A (en) * | 2018-04-11 | 2018-08-24 | 重庆建峰浩康化工有限公司 | The environmental protection production of trimethylol melamine |
| CN110357825A (en) * | 2018-04-11 | 2019-10-22 | 重庆建峰浩康化工有限公司 | The coproduction of pentahydroxy- and hexamethylolmelamine improves |
| CN110357826A (en) * | 2018-04-11 | 2019-10-22 | 重庆建峰浩康化工有限公司 | The coproduction technique of tetra methylol melamine |
| CN115253973A (en) * | 2022-08-01 | 2022-11-01 | 重庆建峰浩康化工有限公司 | Method for producing wastewater-free hydroxymethyl melamine |
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| CN106117155A (en) * | 2016-06-23 | 2016-11-16 | 重庆建峰浩康化工有限公司 | A kind of trimethylol melamine and hexakis(hydroxymethyl)melamine co-production |
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| EP1607391A1 (en) * | 2004-06-17 | 2005-12-21 | Melamin Kemicna tovarna d.d. Kocevje | Continuous process for production of methylol melamines and use thereof for production of highly etherified melamine resins |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108440432A (en) * | 2018-04-11 | 2018-08-24 | 重庆建峰浩康化工有限公司 | The environmental protection production of trimethylol melamine |
| CN110357825A (en) * | 2018-04-11 | 2019-10-22 | 重庆建峰浩康化工有限公司 | The coproduction of pentahydroxy- and hexamethylolmelamine improves |
| CN110357826A (en) * | 2018-04-11 | 2019-10-22 | 重庆建峰浩康化工有限公司 | The coproduction technique of tetra methylol melamine |
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| CN110357825B (en) * | 2018-04-11 | 2023-01-24 | 重庆建峰浩康化工有限公司 | Improved co-production of pentahydroxy and hexamethylol melamine |
| CN110357826B (en) * | 2018-04-11 | 2023-01-31 | 重庆建峰浩康化工有限公司 | Process for coproducing tetrahydroxymethyl melamine |
| CN115253973A (en) * | 2022-08-01 | 2022-11-01 | 重庆建峰浩康化工有限公司 | Method for producing wastewater-free hydroxymethyl melamine |
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| Publication number | Publication date |
|---|---|
| CN107245057B (en) | 2020-10-27 |
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