The crystallization separation process of aminobenzoic ether mixture
Technical field
The invention belongs to the fine chemical technology field, specifically, the crystallization separation process that relates to a kind of aminobenzoic ether mixture is that raw material carries out the technology that Crystallization Separation is produced Para-Anisidine and Ortho Anisidine in methanol solvate with the aminobenzoic ether mixture promptly.
Background technology
The normal fractionation by distillation that adopts anisidine in the prior art, anisidine exists facility investment and drawbacks such as process cost is big, operational condition harshness in the fractionation by distillation process.
Solution crystallization is a liquid phase production solid crystal product unit process commonly used, and the Crystallization Separation technology has wide development space in modern industry.Crystallization technique is compared with other unit processes has following advantage:
(1) less energy consumption: the crystallization of most compounds is exothermic process, and with rectifying, the unit operation that energy consumptions such as drying are big is compared, and crystallization phases changes potential and only is 1/3~1/7 of rectifying, and separating energy consumption only is 10~30% of rectifying.
(2) be applicable to the separation of complicated systems such as azeotrope: nearly 90% organism compound system is the eutectic type, and the boiling point difference is little, uses the conventional distillation method to be difficult to reach the purpose of separating and purifying.Use extraction,, be subjected to the restriction of physical conditions such as selection of Extractant in operating and be difficult to reach complete isolating purpose though methods such as azeotropic distillation can be separated in theory; Moreover the introducing of other components such as extraction agent increases operational path, increases investment and process cost, and inevitably influences the quality of the finished product.With extraction, rectifying is compared, and does not have the introducing of other materials in the crystallisation process, and the selectivity height of crystallization operation can be produced highly purified product.
(3) the crystallization operation temperature is lower, and is little to the equipment corrosion degree.Particularly to the boiling point height, the system of blast separates easily, the safety performance of crystallization operation, good reliability.
(4) improve operating environment, reduce environmental pollution.The physicochemical property of aminobenzoic ether mixture: the boiling point of the isomers of various anisidines is all than higher, and low temperature is stable down, and pyrolytic decomposition is emitted poisonous gas, especially anisidine is inflammable, and chance naked light, high heat, friction, bump have the incendiary of causing danger.Emit deleterious irritating smog during burning.Form explosive mixture with the oxygenant mixing energy.Therefore crystallization process separates the separation method that the anisidine mixture is a first-selection.
Summary of the invention
The crystallization separation process that the purpose of this invention is to provide a kind of aminobenzoic ether mixture, this technology is fully used fusing point difference (fusing point of Ortho Anisidine, an amino-chloro-benzene and Para-Anisidine sees Table 1) and their dissolubility properties in methyl alcohol of Para-Anisidine and Ortho Anisidine, has overcome anisidine and have facility investment and drawbacks such as process cost is big, operational condition harshness in the fractionation by distillation process.
The technical scheme that realizes above-mentioned purpose is: the aminobenzoic ether mixture adopts the Crystallization Separation method to obtain Para-Anisidine and Ortho Anisidine crude product in methanol solvate, Para-Anisidine and Ortho Anisidine crude product carry out the recrystallization separation and purification respectively in methanol solvate, produce Para-Anisidine and o-amino benzoyl ether product.The described technology step is poly-as follows:
The first step, in stirring and dissolving equipment, add aminobenzoic ether mixture and methyl alcohol, heating makes temperature reach 50 ℃~methanol eddy temperature while stirring, make material dissolution, the aminobenzoic ether mixture contains Para-Anisidine, Ortho Anisidine and a spot of impurity;
Add the removal of impurities discoloring agent in second step, the material after dissolving and decolour except that miscellaneous operation, filtered while hot, filtrate enters cooling crystallizer for the first time, and filter cake is recyclable after treatment to be used again;
The 3rd step, in first time cooling crystallizer, will make with extra care material and be cooled to 7~20 ℃, the Para-Anisidine crystallization is separated out, is filtered, filtrate enters cooling crystallizer for the second time, filter cake enters the Para-Anisidine recrystallizer;
The 4th step, in second time cooling crystallizer, the previous step feed liquid is continued to be cooled to 0-6 ℃, the Ortho Anisidine crystallization is separated out, is filtered, filtrate turns back in the first step stirring and dissolving equipment, filter cake enters the Ortho Anisidine recrystallizer;
The 5th step, in the Para-Anisidine recrystallizer, add a certain amount of methyl alcohol, rising temperature for dissolving, crystallisation by cooling, filtration then, filtrate turned back to for the 3rd step for the first time in the crystallisation by cooling separator, filter cake gets the Para-Anisidine product through vacuum-drying;
The 6th step, in the Ortho Anisidine recrystallizer, add a certain amount of methyl alcohol, rising temperature for dissolving, crystallisation by cooling, filtration then, filtrate turned back to for the 4th step for the second time in the cooling crystallizer, filter cake gets the o-amino benzoyl ether product through vacuum-drying.
Further, the aminobenzoic ether mixture also contains water, methyl alcohol, and the ratio of solid materials and methyl alcohol is in the Crystallization Separation process: 100g: 100ml is to 500g: between the 500ml.
Further, the service temperature in the Crystallization Separation process is 0 ℃ and arrives between the reflux temperature of methyl alcohol that working pressure is between 0.1 to 10.0MPa.
Further, the sorbent material that the adsorption bleaching removal of impurities is adopted is activated carbon, diatomite, adsorbent of molecular sieve or the mixture of two components or three components wherein, and decolouring removal of impurities and filtering temperature are 50~65 ℃, and adsorption and decoloration device is a stirring tank.
After adopting the invention described above to adopt the Crystallization Separation technical scheme, have the following advantages:
(1) less energy consumption: separating energy consumption only is 10~30% of rectifying.
(2) the selectivity height of crystallization operation, the purity height of product.
(3) the crystallization operation temperature is lower, and is little to the equipment corrosion degree.Safety performance, the good reliability of operation.
(4) improve operating environment, reduce environmental pollution.The physicochemical property of aminobenzoic ether mixture: the boiling point of the isomers of various anisidines is all than higher, and low temperature is stable down, and pyrolytic decomposition is emitted poisonous gas, especially anisidine is inflammable, and chance naked light, high heat, friction, bump have the incendiary of causing danger.Emit deleterious irritating smog during burning.Form explosive mixture with the oxygenant mixing energy.Therefore crystallization process separates the separation method that the anisidine mixture is a first-selection.
In addition, select for use methyl alcohol to make the Crystallization Separation solvent three advantages arranged:
(1) boiling point of methyl alcohol is lower, is easy to reclaim.
(2) the direct recycled of the recovery liquid of methyl alcohol.
(3) viscosity of methanol solution is lower, the mixture of anisidine Crystallization Separation in methanol solution, and crystal formation is relatively more perfect.
The fusing point of table 1 Ortho Anisidine and Para-Anisidine
Chemical substance |
Ortho Anisidine |
Para-Anisidine |
Between amino-chloro-benzene |
Fusing point/℃ |
6.22 |
57.2 |
46 |
Description of drawings
Accompanying drawing is the process flow sheet of the Crystallization Separation of a kind of aminobenzoic ether mixture of the present invention.
Embodiment
The present invention is further detailed explanation below in conjunction with drawings and Examples.
Embodiment one
A kind of crystallization separation process of aminobenzoic ether mixture is a raw material with the aminobenzoic ether mixture promptly, produces the separating technology of Para-Anisidine and Ortho Anisidine, and processing step is as follows:
In the stirring and dissolving still, add aminobenzoic ether mixture and methyl alcohol, the ratio of aminobenzoic ether mixture and methyl alcohol is: 100g: 500ml, heat while stirring, be warming up to the methanol eddy temperature, make material dissolution; In the dissolving material, add adsorbent of molecular sieve and decolour except that miscellaneous operation, filtered while hot, filtrate enters crystallisation by cooling still for the first time; In first time cooling crystallizer, will make with extra care material and be cooled to 10 ℃, the Para-Anisidine crystallization is separated out, is filtered, and filtrate enters crystallisation by cooling still for the second time, and filter cake enters the Para-Anisidine recrystallizer; In second time cooling crystallizer, the previous step feed liquid is continued to be cooled to 0 ℃, the Ortho Anisidine crystallization is separated out, is filtered, and filter cake enters the Ortho Anisidine recrystallizer; In the Para-Anisidine recrystallizer, the ratio that adds Para-Anisidine and methyl alcohol is: 100g: 500ml, under agitation condition, be warming up to the methanol eddy temperature, make material dissolution, be cooled to 10 ℃ of crystallizations, filtration then, filter cake gets the Para-Anisidine product through vacuum-drying, and purity reaches more than 98%; In the Ortho Anisidine recrystallizer, the ratio that adds Ortho Anisidine and methyl alcohol is: 100g: 500ml under agitation condition, makes material dissolution, be cooled to 2 ℃ of crystallizations, filtration then, filter cake gets the Ortho Anisidine product purity through vacuum-drying and reaches more than 98%.
Embodiment two
A kind of crystallization separation process of aminobenzoic ether mixture is a raw material with the aminobenzoic ether mixture promptly, produces the separating technology of Para-Anisidine and Ortho Anisidine, and processing step is as follows:
In the stirring and dissolving still, add aminobenzoic ether mixture and methyl alcohol, the ratio of aminobenzoic ether mixture and methyl alcohol is: 200g: 500ml, heat while stirring, be warming up to 80 ℃, make material dissolution; In the dissolving material, add adsorbent of molecular sieve and decolour except that miscellaneous operation, filtered while hot, filtrate enters crystallisation by cooling still for the first time; In first time cooling crystallizer, will make with extra care material and be cooled to 18 ℃, the Para-Anisidine crystallization is separated out, is filtered, and filtrate enters crystallisation by cooling still for the second time, and filter cake enters the Para-Anisidine recrystallizer; In second time cooling crystallizer, the previous step feed liquid is continued to be cooled to 5 ℃, the Ortho Anisidine crystallization is separated out, is filtered, and filter cake enters the Ortho Anisidine recrystallizer; In the Para-Anisidine recrystallizer, the ratio that adds Para-Anisidine and methyl alcohol is: 200g: 500ml, under agitation condition, be warming up to the methanol eddy temperature, make material dissolution, be cooled to 10 ℃ of crystallizations, filtration then, filter cake gets the Para-Anisidine product through vacuum-drying, and purity reaches more than 98%; In the Ortho Anisidine recrystallizer, the ratio that adds Ortho Anisidine and methyl alcohol is: 200g: 500ml under agitation condition, makes material dissolution, be cooled to 2 ℃ of crystallizations, filtration then, filter cake gets the Ortho Anisidine product purity through vacuum-drying and reaches more than 98%.
Embodiment three
A kind of crystallization separation process of aminobenzoic ether mixture is a raw material with the aminobenzoic ether mixture promptly, produces the separating technology of Para-Anisidine and Ortho Anisidine, and processing step is as follows:
In the stirring and dissolving still, add aminobenzoic ether mixture and methyl alcohol, the ratio of aminobenzoic ether mixture and methyl alcohol is: 300g: 500ml, heat while stirring, be warming up to the methanol eddy temperature, make material dissolution; In the dissolving material, add adsorbent of molecular sieve and decolour except that miscellaneous operation, filtered while hot, filtrate enters crystallisation by cooling still for the first time; In first time cooling crystallizer, will make with extra care material and be cooled to 7 ℃, the Para-Anisidine crystallization is separated out, is filtered, and filtrate enters crystallisation by cooling still for the second time, and filter cake enters the Para-Anisidine recrystallizer; In second time cooling crystallizer, the previous step feed liquid is continued to be cooled to 1 ℃, the Ortho Anisidine crystallization is separated out, is filtered, and filter cake enters the Ortho Anisidine recrystallizer; In the Para-Anisidine recrystallizer, the ratio that adds Para-Anisidine and methyl alcohol is: 300g: 500ml, under agitation condition, be warming up to the methanol eddy temperature, make material dissolution, be cooled to 10 ℃ of crystallizations, filtration then, filter cake gets the Para-Anisidine product through vacuum-drying, and purity reaches more than 99%; In the Ortho Anisidine recrystallizer, the ratio that adds Ortho Anisidine and methyl alcohol is: 300g: 500ml under agitation condition, makes material dissolution, be cooled to 2 ℃ of crystallizations, filtration then, filter cake gets the Ortho Anisidine product purity through vacuum-drying and reaches more than 98%.