CN210314062U - Refining device for crude methyl methacrylate - Google Patents
Refining device for crude methyl methacrylate Download PDFInfo
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- CN210314062U CN210314062U CN201921097078.4U CN201921097078U CN210314062U CN 210314062 U CN210314062 U CN 210314062U CN 201921097078 U CN201921097078 U CN 201921097078U CN 210314062 U CN210314062 U CN 210314062U
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Abstract
The utility model belongs to the technical field of methyl methacrylate's preparation, specificly relate to a refining plant of thick methyl methacrylate. The device comprises an extraction tower, wherein the top of the extraction tower is connected with a light liquid line, the light liquid line is connected with a solvent recovery-deacidification coupling tower, a line extraction outlet of the solvent recovery-deacidification coupling tower is connected with a light component removal tower through a pipeline, the bottom of the solvent recovery-deacidification coupling tower is connected with a heavy component evaporation tower through a pipeline, the top of the light component removal tower is connected with a light component line, the bottom of the light component removal tower is connected with a heavy component removal tower through a pipeline, the top of the heavy component removal tower is connected with a fine MMA line, a tower kettle of the heavy component evaporation tower is connected with a thin film evaporator in series, and the thin film. The utility model discloses a two solvent extraction-refined method purifies, can effectively overcome because of MMA easily forms the difficult problem of rectification separation with methyl alcohol and water azeotrope to and the not thorough difficult problem of phase separation that water extraction exists, have the advantage that material consumption, energy consumption are low.
Description
Technical Field
The utility model belongs to the technical field of methyl methacrylate's preparation, specificly relate to a refining plant of thick methyl methacrylate.
Background
Methyl Methacrylate (MMA) is an important chemical raw material and an intermediate, and is widely applied to various fields of organic glass, coating, optical lenses, optical fibers and the like. With the continuous expansion of the MMA consumption field and the continuous improvement of the environmental protection requirement, all parties are actively improving the existing MMA production technology, and at present, the preparation of MMA by using isobutene or tert-butanol as a raw material and adopting a three-step method is a very competitive clean technical route: first to Methacrolein (MAL), second to methacrylic acid (MAA), and third to MAA and methanol esterification to produce MMA. The esterification reaction of MAA and methanol is a reversible reaction, and crude methyl methacrylate which is an esterification product contains MMA, MAA, methanol, water and oligomers, and needs to be refined. MMA has strict requirements on purity, impurities can reduce the transparency of organic glass (PMMA), and defects of the organic glass (PMMA) are caused, so that an MMA refining process becomes a research hotspot, and related researches are reported.
Chinese patents CN 105636929a and CN 106588654a wash crude MMA with water as extractant to cause phase separation, thereby obtaining aqueous phase and organic phase, and then use two rectification columns to remove light and heavy impurities in the organic phase respectively to obtain refined MMA. However, water and MMA have certain intersolubility, the existence of methanol can increase the solubility of MMA in the water phase at the bottom of the extraction tower, and the water extraction process has the defect of incomplete phase separation, so that material loss or overlarge equipment investment is caused.
In the Chinese patent CN 103833551A, crude MMA is extracted by taking water and n-hexane as solvents, and the refined MMA is obtained by three rectifications of an extract phase. However, materials enter a plurality of rectifying towers in sequence, and are easy to polymerize at the bottoms of the rectifying towers and at the reboiler, and the recovery rate of the methyl methacrylate is low. In addition, the raw material crude MMA of the patent does not contain MAA, and the details related to the separation of MAA and MMA are not mentioned, so that the method is suitable for purifying crude MMA generated by the oxidative esterification of Methacrylic Acid (MAL), and the application range of the method is narrow.
Chinese patents CN 108473412A and CN 108137475A adopt a dividing wall distillation tower to purify and purify crude MMA. The above technical documents are only suitable for refining and purifying crude MMA with low methanol and low water content, and in addition, the dividing wall distillation tower is sensitive to various parameters, the operation stability interval is small, and even slight changes of feed composition and temperature can cause great fluctuation of separation effect.
SUMMERY OF THE UTILITY MODEL
The utility model aims to overcome the defects of the prior art and provide a refining device for coarse methyl methacrylate. The refining device adopts a double-solvent extraction-refining method to purify MMA, can effectively overcome the problem that MMA is difficult to rectify and separate because the MMA is easy to generate an azeotrope with methanol and water, can effectively overcome the problem that the phase separation is not complete in water extraction, and has the advantages of low material consumption and low energy consumption.
Crude methyl methacrylate's refining plant, including the extraction tower, extraction tower top links to each other with the light liquid line, the light liquid line links to each other with solvent recovery-deacidification coupling tower, solvent recovery-deacidification coupling tower side line production mouth links to each other with the lightness-removing tower through the pipeline, solvent recovery-deacidification coupling tower bottom links to each other with the heavy ends evaporating tower through the pipeline, lightness-removing tower top is two the tunnel, flow back into lightness-removing tower all the way, another way converges into the light ends, lightness-removing tower bottom links to each other with the weight-removing tower through the pipeline, the weight-removing tower top is two the tunnel, reflux heavy ends tower all the way, another way converges into smart MMA line, heavy ends evaporating tower cauldron series connection film evaporator, film evaporator links to each other with the heavy ends.
Wherein:
the bottom of the extraction tower is connected with a heavy liquid line, the heavy liquid line is connected with a methanol recovery tower, the bottom of the methanol recovery tower is connected with a reboiler through a pipeline, the top of the methanol recovery tower is connected with a tower top condenser through a pipeline, the outlet of the tower top condenser is divided into two paths through a pipeline, one path of reflux enters the methanol recovery tower, the other path of reflux enters a regenerated methanol line, the bottom of the methanol recovery tower is connected with a regenerated water line, the regenerated water line is divided into two paths, the other path of reflux returns the extraction tower, and the other path of reflux.
The tower bottom of the solvent recovery-deacidification coupling tower is provided with a reboiler, the solvent recovery-deacidification coupling tower is connected with a tower top condenser through a pipeline, the outlet of the tower top condenser is divided into two paths through the pipeline, one path of the solution reflows into the solvent recovery-deacidification coupling tower, and the other path of the solution converges into an organic extractant line.
The bottom of the light component removal tower is provided with a reboiler, the light component removal tower is connected with a tower top condenser through a pipeline, the outlet of the tower top condenser is divided into two paths through a pipeline, one path of the light component removal tower reflows to the light component removal tower, and the other path of the light component removal tower converges to a light component.
The tower bottom of the heavy component removal tower is provided with a reboiler, the heavy component removal tower is connected with a tower top condenser through a pipeline, the outlet of the tower top condenser is divided into two paths through the pipeline, one path of the condenser flows back into the heavy component removal tower, the other path of the condenser converges into a refined MMA line, and the bottom of the heavy component removal tower is connected with a solvent recovery-deacidification coupling tower through the pipeline.
The heavy component evaporation tower is provided with a reboiler at the bottom, the heavy component evaporation tower is connected with a tower top condenser through a pipeline, the outlet of the tower top condenser is divided into two paths through a pipeline, one path of the heavy component evaporation tower reflows to the heavy component evaporation tower, and the other path of the heavy component evaporation tower converges to an MAA line.
The upper part of the extraction tower is connected with a waterline and a regeneration waterline, and the waterline and the regeneration waterline are opposite to the connection position of the extraction tower and the regeneration waterline and are positioned on a horizontal plane; the middle part of the extraction tower is connected with a crude MMA line, and the lower part of the extraction tower is connected with an organic extractant line.
The extraction tower is a rotary disc extraction tower, the rotary disc extraction tower is divided into 3 parts, the top and the bottom are purification chambers, the middle part is an extraction section, a grid is arranged between the purification chambers and the extraction section to be used as a ballast part, a series of fixing rings are arranged on the inner wall of the extraction section, the extraction section is divided into a plurality of small chambers by the fixing rings, each small chamber is provided with a rotatable disc, the discs are arranged on a rotating shaft positioned in the center of the rotary disc extraction tower, and the rotating shaft is driven by a motor arranged at the top of the rotary disc.
1-5 side line extraction outlets of the solvent recovery-deacidification coupling tower; the methanol recovery tower is one of a plate tower or a packed tower, and the plate tower is a composite hole miniature high-efficiency float valve tower tray; the solvent recovery-deacidification coupling tower, the light component removal tower, the heavy component removal tower and the heavy component evaporation tower are all composite towers, namely, a rectifying section adopts regular packing, and a stripping section adopts a plate-type tower tray.
The solvent recovery-deacidification coupling tower, the light component removal tower, the heavy component removal tower and the heavy component evaporation tower are connected with a uniform polymerization inhibitor line at the top of the tower; the methanol recovery tower, the solvent recovery-deacidification coupling tower, the light component removal tower, the heavy component removal tower and the heavy component evaporation tower are connected with a vacuum system through outlet pipelines of condensers at the tops of the towers.
Refining plant of thick methyl methacrylate, be applicable to MAA and the purification refining process of the thick MMA that the methanol esterification reaction generated, further say and be applicable to and use isobutene or tertiary butanol as the raw materials, adopt the purification of the thick MMA of three-step method preparation MMA in-process to purify.
MAA esterification is a reversible reaction, contains MMA, MAA, methyl alcohol, water and other accessory substances in the thick MMA, wherein MMA and water, methyl alcohol generate ternary heterogeneous azeotrope easily, can not pass through the rectification separation, to this, thick methyl methacrylate's refining plant, at first adopt the method of extraction to carry out initial separation to thick MMA, the water and the methyl alcohol in the thick MMA of desorption, then carry out a series of rectification purifications to thick MMA, successively remove MAA, light component and heavy component in the thick MMA, obtain refined MMA.
In view of the heterogeneous azeotropic system of thick MMA has organic phase and aqueous phase simultaneously, according to the kind of extractant and the special materialization nature of azeotrope, crude methyl methacrylate's refining plant, adopt the method of two solvent extractions, adopt water and organic extractant extraction to separate water and methanol in the thick MMA promptly, the organic extractant of adoption is n-hexane or cyclohexane. Compared with the methods in CN 105636929A and CN 106588654A, the technology can effectively overcome the defect of incomplete phase separation, meet the separation requirement of MMA, and has the characteristic of high product yield.
The working principle and the process of the refining device of the coarse methyl methacrylate are as follows:
the extraction water from the water line, the crude MMA from the crude MMA line and the extraction solvent from the organic extractant line respectively enter the extraction tower from the upper part, the middle part and the lower part, under the extraction action of the double solvents, MMA, MAA and organic by-products in the crude MMA enter an organic extraction phase, enter the solvent recovery-deacidification coupling tower from the top of the extraction tower along the pipeline, and water and methanol in the crude MMA enter an extraction water phase and enter the methanol recovery tower from the bottom of the extraction tower.
The extraction tower is a rotary disc extraction tower, a series of fixing rings are arranged on the inner wall of the extraction section, the fixing rings divide the extraction section into a plurality of small chambers, each small chamber is provided with a rotatable disc, the discs are arranged on a rotating shaft positioned in the center of the tower, and the rotating shaft is driven by a motor arranged at the top of the tower. A certain gap is formed between the inner hole of the fixing ring and the periphery of the turntable so as to facilitate the loading of the turntable. The top and bottom of the tower are clean rooms, which are designed with large height and volume to ensure good mass transfer and separation of the two liquid phases, so that the retention time is long enough. A grid is arranged between the purification chamber and the extraction section as a ballast part to eliminate the rotational kinetic energy of the fluid obtained in the extraction section and improve the separation effect of the upper and lower purification chambers.
The materials in the heavy liquid line at the bottom of the extraction tower are methanol and water, the materials enter a methanol recovery tower, the methanol and the water are separated by utilizing the difference of relative volatility of the methanol and the water under the action of the thermal drive of a reboiler, the methanol material obtained at the top of the tower partially flows back after being cooled by a tower top condenser, part of the methanol material is externally extracted along a regenerated methanol line, and the externally extracted methanol can be reused as MAA esterification raw materials. And part of the water material obtained from the tower bottom is used as extraction water and returns to the extraction tower along the regeneration water line, and part of the water material is discharged along the sewage line. The regeneration water line and the connection part of the water line and the extraction tower are positioned at a horizontal plane.
The materials in the light liquid line at the top of the extraction tower are MMA, MAA, an organic extractant and esterification byproducts, the materials enter a solvent recovery-deacidification coupling tower, fraction separation is realized by utilizing the difference of relative volatility of the materials of each part under the action of thermal drive of a reboiler, the organic extractant obtained at the top of the tower partially flows back after being cooled by a condenser at the top of the tower, part of the organic extractant as a circulating organic extractant enters an organic extractant line, the materials containing MMA obtained by side mining enter a lightness-removing tower for further refining treatment, the tower bottom materials mainly comprise MAA, oligomer, polymerization inhibitor and other impurities, and the materials enter a heavy component evaporation tower along the pipeline for further treatment. The number of side line extraction outlets of the solvent recovery-deacidification coupling tower is 1-5.
The light-weight removal tower mainly has the effects that light impurities such as methyl isobutyrate, methyl propionate, methyl acrylate and the like in MMA are removed, the light impurities obtained at the tower top are partially refluxed after being condensed by a condenser at the tower top under the action of thermal driving of a reboiler, part of the light impurities are externally extracted along a light component line, and materials at the tower bottom enter a heavy-weight removal tower along a pipeline for next treatment.
The heavy component removal tower mainly removes the heavy components such as dimers in MMA, refined MMA obtained at the tower top is partially refluxed after being condensed by a condenser at the tower top under the action of heat drive of a reboiler, and part of refined MMA is discharged along a refined MMA line. The tower bottom material enters a solvent recovery-deacidification coupling tower along a pipeline.
Under the action of heat drive of a reboiler, MAA obtained at the top of the tower is partially refluxed after being condensed by a condenser at the top of the tower, and part of MAA is discharged along an MAA line. Heavy components are obtained at the bottom of the column, for example: the utility model discloses in polymerization inhibitor, the bottom of each tower reboiler thermal action that each tower top added dimerization methacrylic acid, poly methacrylic acid and with the esterification product and the Michael addition product of methyl alcohol that generate down. Therefore, the utility model discloses at a heavy ends evaporation tower cauldron series connection film evaporator, further concentrate the heavy ends of tower cauldron, partial heavy matter is decomposed in film evaporator, retrieves methacrylic acid, methyl methacrylate to reduce methacrylic acid's consumption, all the other heavy matters are arranged outward along the recombination separated time. In order to avoid the polymerization and carbonization of the heavy components, the thin-film evaporator is operated in vacuum, and the outlet of the thin-film evaporator is connected with a vacuum system.
MMA is a heat-sensitive compound and is easily polymerized by heating at the bottom of the rectifying tower and the reboiler, and for this purpose, the methanol recovery tower, the solvent recovery-deacidification coupling tower, the light component removal tower, the heavy component removal tower and the heavy component evaporation tower adopt low-pressure rectification to reduce the internal temperature of each tower and prevent MMA polymerization. The above-mentioned overhead condenser outlet lines of each column are connected to a vacuum system, which may consist of any known type of vacuum pump, such as a liquid ring vacuum pump or a dry compressor system or any other equivalent device.
In the production process, as MMA is polymerized, the surface tension between phases is reduced, emulsification is easy to occur, and the concentration of the polymerization inhibitor is ensured to be not lower than 300PPM in actual operation. Polymerization inhibitor lines are additionally arranged on the overhead pipelines (the part between the overhead and the overhead condenser) of the solvent recovery-deacidification coupling tower, the light component removal tower, the heavy component removal tower and the heavy component evaporation tower. The polymerization inhibitor is selected from one or more of 2, 4-dimethyl-6-tert-butylphenol, hydroquinone, phenothiazine, copper dibutyldithiocarbamate, nitroxide radical piperidinol or tetramethyl piperidine nitroxide radical phosphite triester.
The methanol recovery tower is one of a plate tower or a packed tower, preferably a plate tower, and further preferably a composite hole micro high-efficiency float valve tray.
The solvent recovery-deacidification coupling tower, the light component removal tower, the heavy component removal tower and the heavy component evaporation tower are combined towers, namely, regular packing is adopted in the rectification section, stainless steel corrugated wire mesh packing is preferably adopted, and a plate-type tower tray is adopted in the stripping section. The advantages of the above design are: the requirements of the separation precision of the rectifying section can be met, and the characteristics of high viscosity, easiness in blockage and enrichment in the stripping section of heavy component materials are considered, so that the maintenance of the stripping section is facilitated.
Compared with the prior art, the utility model, following beneficial effect has:
(1) crude methyl methacrylate's refining plant, adopt two solvent extraction-refined method purification MMA, can effectively overcome because of MMA easily generates the difficult problem of rectification separation with methyl alcohol and water azeotrope, can effectively overcome the not thorough difficult problem of phase separation that water extraction exists, have the advantage that material consumption, energy consumption are low.
(2) Crude methyl methacrylate's refining plant, the MAA that methanol and water, heavy ends evaporating tower that the separation of methanol recovery tower obtained can both recycle, further reduced the device material consumption.
(3) Crude methyl methacrylate's refining plant, solvent recovery-deacidification coupling tower, take off the light tower, take off heavy tower and heavy ends evaporation tower and be combined type tower, can satisfy the requirement of rectification section separation precision, consider again that heavy ends material viscosity is big, easily block up and at the characteristics of stripping section enrichment, make things convenient for the stripping section to overhaul.
(4) Thick methyl methacrylate's refining plant, add and establish heavy ends evaporation tower and film evaporator, to dimerization methacrylic acid, poly methacrylic acid that each tower bottom reboiler thermal action produced down and carry out recycle once more with the esterification product and the michael addition product of methyl alcohol, improved the MMA rate of recovery.
Drawings
FIG. 1 is a schematic view of a crude methyl methacrylate refining apparatus;
FIG. 2 is a schematic diagram of an extraction column.
In the figure: 1. an organic extractant line; 2. coarse MMA lines; 3. a waterline; 4. an extraction tower; 5. a methanol recovery tower; 6. a sewage line; 7. regenerating a methanol line; 8. a solvent recovery-deacidification coupling tower; 9. a light component removal tower; 10. light component lines; 11. a de-weighting tower; 12. fine MMA lines; 13. a heavy component evaporation column; 14. MAA line; 15. a thin film evaporator; 16. recombining the branch lines; 17. A vacuum system; 18. a polymerization inhibitor line; 19. a regeneration waterline; 20. a motor; 21. a light liquid line; 22. a clean room; 23. a grid; 24. a fixing ring; 25. a disc; 26. heavy liquid line.
Detailed Description
The present invention will be further described with reference to the following examples.
Example 1
A refining device of crude methyl methacrylate comprises an extraction tower 4, wherein the top of the extraction tower 4 is connected with a light liquid line 21, the light liquid line 21 is connected with a solvent recovery-deacidification coupling tower 8, a side line extraction port of the solvent recovery-deacidification coupling tower 8 is connected with a lightness-removing tower 9 through a pipeline, the bottom of the solvent recovery-deacidification coupling tower 8 is connected with a heavy component evaporation tower 13 through a pipeline, the top of the lightness-removing tower 9 is divided into two paths, one path reflows into the lightness-removing tower 9, the other path merges into a light component line 10, the bottom of the lightness-removing tower 9 is connected with a heavy component removal tower 11 through a pipeline, the top of the heavy component removal tower 11 is divided into two paths, the other path reflows into a fine MMA line 12, the bottoms of the heavy component evaporation tower 13 are connected with a thin film evaporator 15 in series, and the thin film evaporator 15 is connected with.
Wherein:
4 bottoms of extraction tower are continuous with heavy liquid line 26, heavy liquid line 26 links to each other with methanol recovery tower 5, 5 bottoms of methanol recovery tower link to each other with the reboiler through the pipeline, 5 tops of the tower of methanol recovery tower are continuous with the overhead condenser through the pipeline, overhead condenser export is divided into two the tunnel through the pipeline, reflux all the way goes into methanol recovery tower 5, another way is imported regeneration methyl alcohol line 7, 5 bottoms of methanol recovery tower are continuous with regeneration waterline 19, regeneration waterline 19 is divided into two the tunnel, return extraction tower 4 all the way, converge into sewage line 6 all the way.
The tower bottom of the solvent recovery-deacidification coupling tower 8 is provided with a reboiler, the solvent recovery-deacidification coupling tower 8 is connected with a tower top condenser through a pipeline, the outlet of the tower top condenser is divided into two paths through a pipeline, one path of the condenser reflows into the solvent recovery-deacidification coupling tower 8, the other path of the condenser converges into the organic extractant line 1, the side draw-out port of the solvent recovery-deacidification coupling tower 8 is connected with a lightness-removing tower 9 through a pipeline, and the bottom of the solvent recovery-deacidification coupling tower 8 is connected with a heavy component evaporation tower 13 through a pipeline.
The bottom of the light component removal tower 9 is provided with a reboiler, the light component removal tower 9 is connected with a tower top condenser through a pipeline, the outlet of the tower top condenser is divided into two paths through the pipeline, one path of the condenser reflows to the light component removal tower 9, and the other path of the condenser converges to a light component line 10.
The tower bottom of the heavy component removal tower 11 is provided with a reboiler, the heavy component removal tower 11 is connected with a tower top condenser through a pipeline, the outlet of the tower top condenser is divided into two paths through a pipeline, one path of the condenser flows back into the heavy component removal tower 11, the other path of the condenser converges into a refined MMA line 12, and the bottom of the heavy component removal tower 11 is connected with the solvent recovery-deacidification coupling tower 8 through a pipeline.
The bottom of the heavy component evaporation tower 13 is provided with a reboiler, the heavy component evaporation tower 13 is connected with a tower top condenser through a pipeline, the outlet of the tower top condenser is divided into two paths through a pipeline, one path of the heavy component evaporation tower reflows to the heavy component evaporation tower 13, and the other path of the heavy component evaporation tower converges to an MAA line 14.
The upper part of the extraction tower 4 is connected with a water line 3 and a regeneration water line 19, and the connecting positions of the water line 3 and the regeneration water line 19 and the extraction tower 4 are opposite and are positioned on a horizontal plane; the middle part of the extraction tower 4 is connected with a crude MMA line 2, and the lower part of the extraction tower 4 is connected with an organic extractant line 1.
The extraction tower 4 is a rotary disc extraction tower, the rotary disc extraction tower is divided into 3 parts, the top and the bottom are provided with purification chambers 22, the middle part is provided with an extraction section, a grid 23 serving as a ballast part is arranged between the purification chambers 22 and the extraction section, the inner wall of the extraction section is provided with a series of fixing rings 24, the extraction section is divided into a plurality of small chambers by the fixing rings 24, each small chamber is provided with a rotatable disc 25, the disc 25 is arranged on a rotating shaft positioned in the center of the rotary disc extraction tower, and the rotating shaft is driven by a motor 20 arranged at the top of the.
1-5 side line extraction outlets of the solvent recovery-deacidification coupling tower are arranged; the methanol recovery tower 5 is one of a plate tower or a packed tower, and the plate tower is a composite hole miniature high-efficiency float valve tower tray; the solvent recovery-deacidification coupling tower 8, the light component removal tower 9, the heavy component removal tower 11 and the heavy component evaporation tower 13 are all composite towers, namely, a rectification section adopts regular packing, and a stripping section adopts a plate tray.
A solvent recovery-deacidification coupling tower 8, a light component removal tower 9, a heavy component removal tower 11 and a heavy component evaporation tower 13 are connected with a uniform polymerization inhibitor line 18 at the top of the tower; the outlet pipelines of the top condensers of the methanol recovery tower 5, the solvent recovery-deacidification coupling tower 8, the light component removal tower 9, the heavy component removal tower 11 and the heavy component evaporation tower 13 are all connected with a vacuum system 17.
The working principle and the process of the refining device of the coarse methyl methacrylate are as follows:
the extraction water from the water line 3, the crude MMA from the crude MMA line 2 and the extraction solvent from the organic extractant line 1 respectively enter the extraction tower 4 from the upper part, the middle part and the lower part, under the extraction action of the double solvent, MMA, MAA and organic by-products in the crude MMA enter an organic extraction phase, enter the solvent recovery-deacidification coupling tower 8 from the top of the extraction tower 4 along a pipeline, while water and methanol in the crude MMA enter an extraction water phase, and enter the methanol recovery tower 5 from the bottom of the extraction tower 4.
The extraction column 4 is a rotating disc extraction column, and a series of retaining rings 24 are mounted on the inner wall of the extraction section, the retaining rings 24 dividing the extraction section into a plurality of cells, each cell having a rotatable disc 25, the discs 25 being mounted on a shaft located in the center of the column, the shaft being driven by a motor 20 mounted at the top of the column. A certain gap is formed between the inner hole of the fixing ring 24 and the periphery of the turntable so as to facilitate the loading of the turntable. The top and bottom of the column are clean rooms 22, and to ensure good mass transfer and separation of the two liquid phases, the height and volume of the clean room 22 are designed to be large, so that the residence time is long enough. A grid 23 is installed between the clean room 22 and the extraction section as a ballast to eliminate the rotational kinetic energy of the fluid in the extraction section and improve the separation of the upper and lower clean rooms 22.
The materials in the heavy liquid line 26 at the bottom of the extraction tower 4 are methanol and water, the materials enter the methanol recovery tower 5, the methanol and the water are separated by utilizing the difference of relative volatility of the methanol and the water under the action of the thermal drive of a reboiler, the methanol material obtained at the top of the tower partially flows back after being cooled by a condenser at the top of the tower, part of the methanol material is externally extracted along the regenerated methanol line 7, and the externally extracted methanol can be reused as MAA esterification raw materials. The water material obtained from the bottom of the tower is partially returned to the extraction tower 4 as extraction water along a regeneration water line 19, and is partially discharged along a sewage line 6. The regeneration water line 19 and the connection of the water line 3 and the extraction column 4 are at a level.
The materials in the light liquid line 21 at the top of the extraction tower 4 are MMA, MAA, an organic extracting agent and esterification reaction byproducts, the partial materials enter a solvent recovery-deacidification coupling tower 8, under the action of thermal drive of a reboiler, fraction separation is realized by utilizing the difference of relative volatility of the materials of each part, the organic extracting agent part obtained at the top of the tower is cooled by a condenser at the top of the tower and then partially flows back, part of the organic extracting agent part is taken as a circulating organic extracting agent to enter an organic extracting agent line 1, the material containing MMA obtained by side mining enters a lightness-removing tower 9 for further refining treatment, the tower bottom materials mainly comprise MAA, oligomer, a polymerization inhibitor and other impurities, and the partial materials enter a heavy component evaporation tower 13 along a pipeline for further treatment. The number of the side extraction ports of the solvent recovery-deacidification coupling tower is 1-5.
The light-weight removal tower 9 mainly removes light impurities such as methyl isobutyrate, methyl propionate, methyl acrylate and the like in MMA, the light impurities obtained at the tower top partially reflux after being condensed by a condenser at the tower top under the action of heat drive of a reboiler, part of the light impurities are extracted along a light component line 10, and materials at the tower bottom enter a heavy-weight removal tower 11 along a pipeline for further treatment.
The heavy component removal tower 11 mainly removes the heavy components such as the dimer in the MMA, and under the action of thermal drive of a reboiler, the refined MMA obtained at the tower top is partially refluxed after being condensed by a condenser at the tower top, and is partially discharged along a refined MMA line 12. The tower bottom material enters a solvent recovery-deacidification coupling tower 8 along a pipeline.
Under the action of the heat drive of the reboiler, MAA obtained at the top of the tower is partially refluxed after being condensed by the condenser at the top of the tower, and part of MAA is discharged along an MAA line 14. Heavy components are obtained at the bottom of the column, for example: the utility model discloses in polymerization inhibitor, the bottom of each tower reboiler thermal action that each tower top added dimerization methacrylic acid, poly methacrylic acid and with the esterification product and the Michael addition product of methyl alcohol that generate down. Therefore, the utility model discloses at heavy ends evaporation tower 13 tower cauldron series connection a film evaporator 15, further concentrate the heavy ends of tower cauldron, partial heavy matter is decomposed in film evaporator 15, retrieves methacrylic acid, methyl methacrylate to reduce methacrylic acid's consumption, all the other heavy matters are arranged outward along recombination separated time 16. In order to avoid the polymerization and carbonization of the heavy components, the thin-film evaporator 15 is operated under vacuum, the outlet of the thin-film evaporator 15 being connected to a vacuum system 17.
MMA is a heat-sensitive compound and is easily polymerized by heating at the bottom of the rectifying column and at the reboiler, and for this purpose, the methanol recovery column 5, the solvent recovery-deacidification coupling column 8, the light component removal column 9, the heavy component removal column 11 and the heavy component evaporation column 13 are subjected to low-pressure rectification to lower the internal temperature of each column and thereby prevent MMA polymerization. The above-mentioned overhead condenser outlet lines of each column are connected to a vacuum system 17, which vacuum system 17 may consist of any known type of vacuum pump, such as a liquid ring vacuum pump or a dry compressor system or any other equivalent device.
In the production process, as MMA is polymerized, the surface tension between phases is reduced, emulsification is easy to occur, and the concentration of the polymerization inhibitor is ensured to be not lower than 300PPM in actual operation. A polymerization inhibitor line 18 is additionally arranged on the top pipelines (the part between the top of the tower and the top of the tower condenser) of the solvent recovery-deacidification coupling tower 8, the light component removing tower 9, the heavy component removing tower 11 and the heavy component evaporating tower 13. The polymerization inhibitor is selected from one or more of 2, 4-dimethyl-6-tert-butylphenol, hydroquinone, phenothiazine, copper dibutyldithiocarbamate, nitroxide radical piperidinol or tetramethyl piperidine nitroxide radical phosphite triester.
The methanol recovery tower 5 is one of a plate tower or a packed tower, preferably a plate tower, and further preferably a composite hole micro high-efficiency float valve tray.
The solvent recovery-deacidification coupling tower 8, the light component removal tower 9, the heavy component removal tower 11 and the heavy component evaporation tower 13 are combined towers, namely, regular packing is adopted in the rectification section, stainless steel corrugated wire mesh packing is preferably selected, and a plate tray is adopted in the stripping section. The advantages of the above design are: the requirements of the separation precision of the rectifying section can be met, and the characteristics of high viscosity, easiness in blockage and enrichment in the stripping section of heavy component materials are considered, so that the maintenance of the stripping section is facilitated.
Claims (10)
1. A crude methyl methacrylate refining device, characterized in that: the device comprises an extraction tower (4), wherein the top of the extraction tower (4) is connected with a light liquid line (21), the light liquid line (21) is connected with a solvent recovery-deacidification coupling tower (8), a side line extraction port of the solvent recovery-deacidification coupling tower (8) is connected with a lightness-removing tower (9) through a pipeline, the bottom of the solvent recovery-deacidification coupling tower (8) is connected with a heavy component evaporation tower (13) through a pipeline, the top of the lightness-removing tower (9) is divided into two paths, one path of light component flows back into the lightness-removing tower (9), the other path of light component flows back into a light component line (10), the bottom of the lightness-removing tower (9) is connected with a heavy component removal tower (11) through a pipeline, the top of the heavy component removal tower (11) is divided into two paths, one path of light component flows back into the heavy component removal tower (11), the other path of light component removal tower (13) is merged into an MMA line (12), a tower.
2. The purification apparatus of crude methyl methacrylate as claimed in claim 1, wherein: extraction tower (4) bottom links to each other with heavy liquid line (26), heavy liquid line (26) link to each other with methyl alcohol recovery tower (5), it links to each other with the reboiler to pass through the pipeline at the bottom of methyl alcohol recovery tower (5) tower, methyl alcohol recovery tower (5) top of the tower passes through the pipeline and links to each other with the overhead condenser, overhead condenser export is divided into two the tunnel through the pipeline, go back to methyl alcohol recovery tower (5) all the way, another way converges into regeneration methyl alcohol line (7), methyl alcohol recovery tower (5) bottom of the tower links to each other with regeneration waterline (19), regeneration waterline (19) divide into two the tunnel, return extraction tower (4) all the way, converge into sewage line (6).
3. The purification apparatus of crude methyl methacrylate as claimed in claim 1, wherein: the tower bottom of the solvent recovery-deacidification coupling tower (8) is provided with a reboiler, the solvent recovery-deacidification coupling tower (8) is connected with a tower top condenser through a pipeline, the outlet of the tower top condenser is divided into two paths through a pipeline, one path of the condenser reflows to the solvent recovery-deacidification coupling tower (8), and the other path of the condenser converges to the organic extractant line (1).
4. The purification apparatus of crude methyl methacrylate as claimed in claim 1, wherein: the tower bottom of the light component removing tower (9) is provided with a reboiler, the light component removing tower (9) is connected with a tower top condenser through a pipeline, the outlet of the tower top condenser is divided into two paths through the pipeline, one path of the condenser reflows to the light component removing tower (9), and the other path of the condenser converges to a light component line (10).
5. The purification apparatus of crude methyl methacrylate as claimed in claim 1, wherein: the tower bottom of the heavy component removal tower (11) is provided with a reboiler, the heavy component removal tower (11) is connected with a tower top condenser through a pipeline, the outlet of the tower top condenser is divided into two paths through a pipeline, one path of the outlet flows back into the heavy component removal tower (11), the other path of the outlet converges into a refined MMA line (12), and the bottom of the heavy component removal tower (11) is connected with the solvent recovery-deacidification coupling tower (8) through a pipeline.
6. The purification apparatus of crude methyl methacrylate as claimed in claim 1, wherein: the tower bottom of the heavy component evaporation tower (13) is provided with a reboiler, the heavy component evaporation tower (13) is connected with a tower top condenser through a pipeline, the outlet of the tower top condenser is divided into two paths through a pipeline, one path of the outlet flows back to the heavy component evaporation tower (13), and the other path of the outlet flows back to an MAA line (14).
7. The purification apparatus of crude methyl methacrylate as claimed in claim 1, wherein: the upper part of the extraction tower (4) is connected with a waterline (3) and a regeneration waterline (19), and the connecting positions of the waterline (3) and the regeneration waterline (19) and the extraction tower (4) are opposite and are positioned on a horizontal plane; the middle part of the extraction tower (4) is connected with a crude MMA line (2), and the lower part of the extraction tower (4) is connected with an organic extractant line (1).
8. The purification apparatus of crude methyl methacrylate as claimed in claim 1, wherein: the extraction tower (4) is a rotary disc extraction tower, the rotary disc extraction tower is divided into 3 parts, the top and the bottom are purification chambers (22), the middle part is an extraction section, a grid (23) is arranged between the purification chambers (22) and the extraction section to serve as a ballast part, a series of fixing rings (24) are arranged on the inner wall of the extraction section, the extraction section is divided into a plurality of small chambers by the fixing rings (24), each small chamber is provided with a rotatable disc (25), the disc (25) is arranged on a rotating shaft positioned at the center of the rotary disc extraction tower, and the rotating shaft is driven by a motor (20) arranged at the top of the rotary disc extraction.
9. The purification apparatus of crude methyl methacrylate as claimed in claim 1, wherein: 1-5 side line extraction outlets of the solvent recovery-deacidification coupling tower (8); the methanol recovery tower (5) is one of a plate tower or a packed tower, and the plate tower is a composite hole micro high-efficiency float valve tower tray; the solvent recovery-deacidification coupling tower (8), the light component removal tower (9), the heavy component removal tower (11) and the heavy component evaporation tower (13) are all composite towers, namely, a rectification section adopts regular packing, and a stripping section adopts a plate tray.
10. The purification apparatus of crude methyl methacrylate as claimed in claim 1, wherein: the tops of the solvent recovery-deacidification coupling tower (8), the light component removal tower (9), the heavy component removal tower (11) and the heavy component evaporation tower (13) are connected with a polymerization inhibitor line (18); the outlet pipelines of the condenser at the top of the methanol recovery tower (5), the solvent recovery-deacidification coupling tower (8), the light component removing tower (9), the heavy component removing tower (11) and the heavy component evaporating tower (13) are all connected with a vacuum system (17).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921097078.4U CN210314062U (en) | 2019-07-12 | 2019-07-12 | Refining device for crude methyl methacrylate |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201921097078.4U CN210314062U (en) | 2019-07-12 | 2019-07-12 | Refining device for crude methyl methacrylate |
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| CN210314062U true CN210314062U (en) | 2020-04-14 |
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| CN201921097078.4U Active CN210314062U (en) | 2019-07-12 | 2019-07-12 | Refining device for crude methyl methacrylate |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111574374A (en) * | 2020-06-22 | 2020-08-25 | 北京旭阳科技有限公司 | Separation method and separation equipment for methyl methacrylate crude product |
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2019
- 2019-07-12 CN CN201921097078.4U patent/CN210314062U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111574374A (en) * | 2020-06-22 | 2020-08-25 | 北京旭阳科技有限公司 | Separation method and separation equipment for methyl methacrylate crude product |
| CN111574374B (en) * | 2020-06-22 | 2022-08-23 | 北京旭阳科技有限公司 | Separation method and separation equipment for methyl methacrylate crude product |
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