Process for preparing methyl methacrylate according to aldol condensation method

A technology for the preparation of methyl methacrylate and aldol condensation, which is applied in the field of aldol condensation to prepare methyl methacrylate, can solve the problems of short catalyst life, loss, easy carbonization and deactivation, etc., and improve the single cycle Long service life, ensure online regeneration, and reduce the effect of carbon shrinkage

Active Publication Date: 2017-05-17
PUJING CHEM IND SHA +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the alkali metal catalyst used in aldol condensation is prone to carbon formation and deactivation under high temperature conditions, thus resulting in a short service life of the catalyst. Under this condition, only the fluidized bed process application of Risun Chemical, such as CN102775302A, CN104513163A, is expected Catalyst activity recovery by continuous regeneration
However, compared with the fixed bed, the conversion rate of the fluidized bed is relatively low, and the strength of the

Method used

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  • Process for preparing methyl methacrylate according to aldol condensation method
  • Process for preparing methyl methacrylate according to aldol condensation method
  • Process for preparing methyl methacrylate according to aldol condensation method

Examples

Experimental program
Comparison scheme
Effect test

Example Embodiment

[0023] Example 1

[0024] Such as figure 1 As shown, both X series and Y series have three reactors, that is, n=3, so the formaldehyde source is equally divided into 3 feeds. In this embodiment, methyl propionate and formaldehyde are used as raw materials, which are realized by connecting multiple reactors in series and in parallel, which specifically includes the following steps:

[0025] The X series reactor was put into operation, and the Y series reactor was waiting to be put into use.

[0026] Methyl propionate 1 and the first strand of formaldehyde 2 are heated by the heat exchanger HA1 and enter the X series first reactor A1. The reaction temperature is 330℃, the reaction pressure is 0.6MPa, and the molar ratio of methyl propionate to formaldehyde is 10:1, the liquid hourly space velocity is 1.8 / h; the reacted materials in the first reactor A1 of the X series are cooled by the heat exchanger EA1 and enter the second reactor A2 of the X series together with the second strand o...

Example Embodiment

[0042] Example 2

[0043] As a comparison, the single-cycle service life of the catalyst after the formaldehyde is not fed in stages, that is, the case of n=1, is also investigated. The effect is as follows.

[0044] The reactor reaction operating conditions are shown in the table below.

[0045] temperature reflex Reaction pressure Liquid hourly space velocity Ester-aldehyde ratio A1 reactor345℃ 0.6MPa0.6 / h 3.33:1

[0046] The results of the reactor reaction operation are shown in the table below.

[0047]

[0048] Note: Y MMA Is the space-time yield of methyl methacrylate, g / (Kg.cat.h);

[0049] X HCHO Is the effective conversion rate of formaldehyde, %.

[0050] The experimental results of Example 1 and Example 2 show that the catalyst load is reduced to 1 / 3 of the original (1.8 / h reduced to 0.6 / h), and the ester-aldehyde ratio is reduced from 10:1 to 3.33:1, which guarantees the reactor The unit treatment capacity of the catalyst is the same as the unit treatment capacity of...

Example Embodiment

[0051] Example 3

[0052] Consider the case of n=5, and the catalyst position is 20% Cs / SiO2.

[0053] The reaction operating conditions of each reactor of the X and Y series are shown in the table below.

[0054] A series temperature reflex Reaction pressure Liquid hourly space velocity Ester-aldehyde ratio A1 reactor330℃ 0.6MPa2.5 / h 15:1 A2 reactor340℃ 0.5MPa2.5 / h 14:1 A3 reactor360℃ 0.4MPa2.5 / h 13:1 A4 reactor380℃ 0.3MPa2.5 / h 12:1 A5 reactor400℃ 0.2MPa2.5 / h 11:1 B1 reactor330℃ 0.6MPa2.5 / h 15:1 B2 reactor340℃ 0.5MPa2.5 / h 14:1 B3 reactor360℃ 0.4MPa2.5 / h 13:1 B4 reactor380℃ 0.3MPa2.5 / h 12:1 B5 reactor 400℃ 0.2MPa2.5 / h 11:1

[0055] The regeneration conditions are similar to Example 1.

[0056] According to the above conditions, the reaction results of each reactor are as follows:

[0057]

[0058]

[0059] Note: C MMA Is the space-time yield of methyl methacrylate, g / (Kg.cat.h);

[0060] X HCHO Is the effective conversion rate of formaldehyde, %.

[0061] The X and Y serie...

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PUM

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Abstract

The invention relates to production of methyl methacrylate, in particular to a process for preparing methyl methacrylate according to an aldol condensation method, wherein the process is realized by connecting multiple reactors in series and in parallel. According to the process, the multiple reactors are connected in series, and a methyl propionate stream and multiple formaldehyde streams are fed, so that the effective conversion rate of a raw material formaldehyde can be well increased, and the single-cycle service life of a catalyst can be prolonged; the reactors of two series are connected in parallel, so that regeneration operation over the catalyst which is deactivated is realized without shutdown, and the whole system can run normally. Compared with the prior art, the process has the advantages that unfavorable factors such as the short service life of the aldol condensation catalyst and the high requirement on the catalyst during use of a fluidized bed are well eliminated, and the process has high application value and good economic benefits.

Description

technical field [0001] The invention relates to a production process of methyl methacrylate, in particular to a process for preparing methyl methacrylate by an aldol condensation method with long catalyst service life and high raw material utilization rate. Background technique [0002] Methyl methacrylate (MMA) is an important organic chemical raw material, mainly used in the production of plexiglass (PMMA), and also widely used in the production of resins, plastics, coatings, adhesives and various industrial additives. From 2009 to 2013, the production capacity and demand of my country's MMA industry both increased rapidly, and the production capacity increased from 420,000 tons / year to 590,000 tons / year, with an average annual compound growth rate of 7.0%; the demand increased from 470,000 tons / year to 690,000 tons / year, with an average annual compound growth rate of 8.0%. Domestically, demand is higher than production capacity growth. Driven by the downstream industry, ...

Claims

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Application Information

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IPC IPC(8): C07C67/343C07C69/54
CPCC07C67/343C07C69/54Y02P20/584
Inventor 骆念军贺俊陈长军
Owner PUJING CHEM IND SHA
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