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Preparation method of high-purity MMA

A technology of high-purity, methyl methacrylate, applied in the field of preparation of high-purity MMA, can solve problems such as large proportion and waste of products, and achieve the effects of reducing discharge and processing, reducing energy consumption for separation, and facilitating rectification and separation

Pending Publication Date: 2022-04-08
WANHUA CHEM GRP CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, judging from the example data in the text, the impurity of MMA is removed by crystallization, and the ratio of the raffinate to the final crystallization product is too large, which also means that more products are wasted
Moreover, in the refined product obtained by final crystallization, there are still relatively large amounts of impurities

Method used

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  • Preparation method of high-purity MMA

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0067] According to the preparation method of the catalyst in the foregoing specific embodiment, 60 mL of a catalyst of type A was prepared, wherein the content of thorium in the carrier was 97 ppm, the content of manganese was 125 ppm, and the content of magnesium was 274 ppm. Methanol, methyl propionate, formaldehyde and water were fed at 40, 110, 11.25 and 1.35 g / hr respectively, and the reaction was controlled at 340° C. and 0.25 MPa (gauge pressure). The reaction gas was condensed at 150° C., and unreacted methanol and methyl propionate were distilled off in a methanol recovery tower to obtain a reaction liquid. After reacting for 20 hours, the contents of main impurities MIB and DEK in the obtained reaction liquid were 0.18wt% and 0.0092wt%, respectively. The reaction liquid first passes through the light component separation tower with a reflux ratio of 420 and an operating pressure of 40kPa absolute. Then in the heavy component separation tower, the MMA product is ext...

Embodiment 2

[0071] According to the preparation method of the catalyst in the foregoing specific embodiment, 60 mL of a type A catalyst was prepared, wherein the content of thorium in the carrier was 24 ppm, the content of manganese was 982 ppm, and the content of magnesium was 450 ppm. Methanol, methyl propionate, formaldehyde and water were fed at 40, 110, 11.25 and 1.35 g / hr respectively, and the reaction was controlled at 340° C. and 0.25 MPa (gauge pressure). The reaction gas was condensed at 150° C., and unreacted methanol and methyl propionate were distilled off in a methanol recovery tower to obtain a reaction liquid. After reacting for 20 hours, the contents of main impurities MIB and DEK in the obtained reaction solution were 0.19 wt% and 0.0079 wt%, respectively. The reaction liquid first passes through the light component separation tower with a reflux ratio of 350 and an absolute pressure of 38kPa. Then in the heavy component separation tower, the MMA product is extracted fr...

Embodiment 3

[0075] According to the preparation method of the catalyst in the foregoing specific embodiment, 60 mL of the B-type catalyst was prepared, wherein the content of thorium in the carrier was 19 ppm, the content of manganese was 416 ppm, and the content of magnesium was 2747 ppm. Methanol, methyl propionate, formaldehyde and water were fed at 40, 110, 11.25 and 1.35 g / hr respectively, and the reaction was controlled at 340° C. and 0.25 MPa (gauge pressure). The reaction gas was condensed at 150° C., and unreacted methanol and methyl propionate were distilled off in a methanol recovery tower to obtain a reaction liquid. After reacting for 20 hours, the contents of main impurities MIB and DEK in the obtained reaction solution were 0.17wt% and 0.0093wt%, respectively. The reaction liquid first passes through the light component separation tower with a reflux ratio of 480 and an operating pressure of 42kPa absolute. Then in the heavy component separation tower, the MMA product is e...

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Abstract

The invention provides a method for preparing high-purity MMA (methyl methacrylate). The method comprises the following steps: S1, reacting propionic acid or propionate with formaldehyde or a formaldehyde parent in a condensation reaction to generate a gas product flow I; s2, treating the gas product flow I to generate a liquid product flow II containing methyl methacrylate and near-boiling-point impurities; s3, carrying out light component rectification on the liquid product flow II under a negative pressure condition, and concentrating near-boiling-point impurities at the tower top and extracting; s4, carrying out heavy component rectification on the tower bottoms in the step S3, and extracting a liquid MMA product of which the impurities are less than those in the liquid product flow II from the top of the tower; wherein in the step S1, the content of thorium in the catalyst is controlled to be 1-100 ppm, the content of manganese is controlled to be 1-1000 ppm, and the content of magnesium is controlled to be 1-3000 ppm. According to the method, the content of impurities with boiling points close to that of MMA in reactants can be obviously reduced, the separation difficulty is reduced, and the purity of an MMA product is improved.

Description

technical field [0001] The invention belongs to the field of organic synthesis, and in particular relates to a preparation method of high-purity MMA. Background technique [0002] Methyl methacrylate (MMA) is an important organic chemical raw material, mainly used to produce polymethyl methacrylate (PMMA) and acrylic resin materials, and is also widely used in the manufacture of other resins, plastics, coatings, adhesives , lubricants, sizing agents, glazing agents, printing and dyeing auxiliaries and insulating filling materials, etc. [0003] MMA is largely used as a monomer for the production of polymethyl methacrylate (PMMA). PMMA is typically formed into sheets that can be molded into a variety of shapes as required for a particular application. It is important that in the preparation of PMMA, the MMA used is required to have the highest purity, even low levels of impurities can cause the PMMA product to have a cloudy or dull appearance or cause it to discolor. In a...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C67/343C07C69/653B01J23/18B01J23/30
Inventor 罗务习易光铨殷艳欣孙康王昀黎源
Owner WANHUA CHEM GRP CO LTD