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A kind of reaction method of paraformaldehyde and its production method

A technology of paraformaldehyde and production methods, applied in the direction of organic chemistry, etc., can solve the problems of tank reactor corrosion, product purity decrease, increase of reaction time and reaction cost, etc.

Active Publication Date: 2022-04-26
CHINA CHEM TECH RES INST +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] However, since the reaction of formaldehyde polymerization to generate paraformaldehyde is a reversible reaction, the equilibrium conversion rate and the single-pass conversion rate of the reaction are low, thereby making the energy consumption of preparing paraformaldehyde high
And because the catalyst used in the reaction is concentrated sulfuric acid, a liquid homogeneous reaction occurs in the tank reactor, making it difficult to separate the catalyst and the reaction materials, resulting in a decrease in product purity, and simultaneously causing corrosion to the tank reactor, improving the production capacity of the tank reactor. Reaction time and reaction cost

Method used

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  • A kind of reaction method of paraformaldehyde and its production method
  • A kind of reaction method of paraformaldehyde and its production method
  • A kind of reaction method of paraformaldehyde and its production method

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Embodiment 1

[0085] This embodiment takes the production system of paraformaldehyde with an annual output of 50,000 tons as an example. The annual operating hours are calculated by 8000h, and the use concentration is 75% formaldehyde solution as raw material, and the solid acid catalyst bed is made of strong acid cation exchange resin. Solid acid catalyst bed, the mass percentage composition of each stream main component in the production system of this paraformaldehyde is shown in Table 1:

[0086] Table 1 Mass content table

[0087] logistics components 101 102 103 104 105 106 107 108 109 110 Formaldehyde (wt%) 75 67 25 45 0.1 1 56.8 38.4 - 60 Water (wt%) 25 33 20 55 99.9 1.5 43.2 61.6 - 40 Paraformaldehyde (wt%) - - 55 - - 44 - - 99.8 - Dichloroethane (wt%) - - - - - 53.5 - - - - Others (wt%) - - - - - - - - 0.2 -

[0088] The 50,000 tons / year paraformaldehyde production system needs to cons...

Embodiment 2

[0092] In this embodiment, the production system of paraformaldehyde with an annual output of 50,000 tons is taken as an example. The annual operating hours are calculated as 8000h, and the use concentration is 65% formaldehyde solution as raw material, and the solid acid catalyst bed is a solid acid containing ZSM5 molecular sieve. Catalyst bed, the mass percentage composition of each stream main component in the production system of this paraformaldehyde is shown in Table 2:

[0093] Table 2 Mass content table

[0094] logistics components 101 102 103 104 105 106 107 108 109 110 Formaldehyde (wt%) 65 63 25 42.2 0.1 1 56.8 38.4 - 60 Water (wt%) 35 37 20 57.8 99.9 1.5 43.2 61.6 - 40 Paraformaldehyde (wt%) - - 55 - - 44 - - 99.7 - Dichloroethane (wt%) - - - - - 53.5 - - - - Others (wt%) - - - - - - - - 0.3 -

[0095] The 50,000 tons / year paraformaldehyde production system needs to...

Embodiment 3

[0099] In this embodiment, the production system of paraformaldehyde with an annual output of 50,000 tons is taken as an example. The annual operating hours are calculated as 8000h, and the use concentration is 70% formaldehyde solution as raw material, and the solid acid catalyst bed is solid acid containing Beta molecular sieves. Catalyst bed, the mass percentage composition of each stream main component in the production system of this paraformaldehyde is shown in Table 3:

[0100] Table 3 Mass content table

[0101] logistics components 101 102 103 104 105 106 107 108 109 110 Formaldehyde (wt%) 70 65 25 43.3 0.1 1 56.8 38.4 - 60 Water (wt%) 30 35 20 56.7 99.9 1.5 43.2 61.6 - 40 Paraformaldehyde (wt%) - - 55 - - 44 - - 99.7 - Dichloroethane (wt%) - - - - - 53.5 - - - - Others (wt%) - - - - - - - - 0.3 -

[0102] The 50,000 tons / year paraformaldehyde production system needs to ...

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Abstract

The invention discloses a reaction method of paraformaldehyde and a production method thereof, relates to the technical field of polyoxymethylene production technology, and aims to solve the problems of low purity and high cost of the paraformaldehyde prepared by reaction. The reaction method of paraformaldehyde comprises: sending formaldehyde solution into the catalytic rectification tower to obtain a ternary azeotrope. Wherein, the solid acid catalyst bed is used to catalyze the trimerization and ring-forming reaction of the formaldehyde solution to obtain a liquid phase reaction product containing paraformaldehyde, and the gas-liquid phase mass transfer structure is used to obtain a liquid phase reaction product from the liquid phase reaction Part of the paraformaldehyde was isolated from the product. The production method of the paraformaldehyde comprises the reaction method of the paraformaldehyde mentioned in the technical scheme. The reaction method of paraformaldehyde provided by the invention and the production method thereof are used for preparing paraformaldehyde.

Description

technical field [0001] The invention relates to the technical field of polyoxymethylene production technology, in particular to a reaction method of paraformaldehyde and a production method thereof. Background technique [0002] At present, a tank reactor can be used to use 65%~75% formaldehyde solution as a raw material, and under the catalysis of concentrated sulfuric acid, the formaldehyde solution undergoes a trimerization and ring formation reaction to generate a reaction product containing paraformaldehyde. The concentration of paraformaldehyde in the reaction product is 15%-20%. When purifying paraformaldehyde from the reaction product, the reaction product can first enter the concentration tower to increase the concentration of paraformaldehyde to more than 50%, thereby obtaining the ternary azeotrope of formaldehyde, water and paraformaldehyde, and then the The ternary azeotrope is sent to the extraction tower, and benzene is used as the extractant to extract the p...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07D323/06
CPCC07D323/06
Inventor 李克景王帆张小明邓兆敬李琳琳雷骞陈洪林
Owner CHINA CHEM TECH RES INST