Method for recycling waste alkali liquor in polyformaldehyde device

A technology of waste lye and polyoxymethylene, applied in organic chemistry and other directions, can solve problems such as waste

Inactive Publication Date: 2014-02-05
TIANJIN BOHUA YONGLI CHEM IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Among them, in the production of dioxane, a large amount of waste lye will be produced, which will be sold at low prices, resulting in huge waste

Method used

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  • Method for recycling waste alkali liquor in polyformaldehyde device

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Effect test

Embodiment 1

[0015] (1) formaldehyde and ethylene glycol are respectively sent into the dioxane synthesis tower to prepare dioxane, and the reaction mol ratio of described formaldehyde and ethylene glycol is 1.01; (2) the dioxane synthesis tower is The gas phase material at the top of the tower is sent to the dioxane concentration tower to remove ethylene glycol and most of the formaldehyde in the dioxane. The bottom extraction amount is 150kg / h; (3) the gas phase discharge from the top of the dioxane concentration tower is cooled and then sent to the extraction tower for extraction with a sodium oxide solution with a mass percentage content greater than 45%; dioxane In the gas phase discharge at the top of the concentration tower, the mass percentage of dioxane is 91%, the mass percentage of ethylene glycol is zero, the mass percentage of formaldehyde and methanol is not more than 2%, and the remainder is water; (4 ) The dioxane that the mass percentage content obtained at the top of the ...

Embodiment 2

[0018] (1) formaldehyde and ethylene glycol are respectively sent into the dioxane synthesis tower to prepare dioxane, and the reaction mol ratio of described formaldehyde and ethylene glycol is 1.1; (2) the dioxane synthesis tower is The gas phase material at the top of the tower is sent into the dioxane concentration tower to remove ethylene glycol and most of the formaldehyde in the dioxane concentration tower. The bottom output is 120kg / h; (3) the gas phase discharge from the top of the dioxane concentration tower is cooled and then sent to the extraction tower for extraction with a sodium oxide solution with a mass percentage content greater than 45%; dioxane In the gas phase discharge at the top of the concentration tower, the mass percentage of dioxane is 90%, the mass percentage of ethylene glycol is zero, the mass percentage of formaldehyde and methanol is not more than 2%, and the remainder is water; (4 ) The dioxane that the mass percentage content obtained at the t...

Embodiment 3

[0021] (1) formaldehyde and ethylene glycol are respectively sent into the dioxane synthesis tower to prepare dioxane, and the reaction mol ratio of described formaldehyde and ethylene glycol is 1.05; (2) the dioxane synthesis tower is The gas phase material at the top of the tower is sent into the dioxane concentration tower to remove ethylene glycol and most of the formaldehyde in the dioxane concentration tower. The bottom extraction amount is 130kg / h; (3) the gas phase discharge from the top of the dioxane concentration tower is cooled and then sent to the extraction tower for extraction with a sodium oxide solution with a mass percentage content greater than 45%; dioxane In the gas phase discharge at the top of the concentration tower, the mass percentage of dioxane is 92%, the mass percentage of ethylene glycol is zero, the mass percentage of formaldehyde and methanol is not more than 2%, and the remainder is water; (4 ) The dioxane that the mass percentage content obtai...

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Abstract

The invention discloses a method for recycling waste alkali liquor in a polyformaldehyde device. The method comprises the following steps: (1) respectively delivering formaldehyde and ethanol into a dioxolane synthesizing tower; (2) delivering a gas phase material at the top of the dioxolane synthesizing tower into a dioxolane concentrating tower so as to remove ethylene glycol and the majority of formaldehyde in dioxolane; (3) cooling and delivering a gas phase discharged material at the top of the dioxolane synthesizing tower into an extraction tower, and extracting by adopting sodium hydroxide with mass percentage of greater than 45%; (4) delivering the dioxolane, with mass percentage of greater than 98%, obtained from the top of the extraction tower into a rectifying tower for purifying; and transporting the waste sodium hydroxide alkali liquor, with mass percentage of 30-35%, obtained from the bottom of the extraction tower to the polyformaldehyde device to prepare a sodium hydroxide solution with mass percentage of 10% below so as to be used for producing trioxymethylene. Any influence on the quality of trioxymethylene products can not be caused by adopting the method.

Description

technical field [0001] The invention relates to a method for recycling waste lye, in particular to a method for recycling waste lye in a polyoxymethylene device. Background technique [0002] Sodium hydroxide (concentration ≥ 45%) has two uses in the production of polyoxymethylene, one is used as an extractant in the production of intermediate product dioxane, and sodium hydroxide with a concentration of more than 45% is used as an extractant to remove A large amount of water in the dioxane is extracted to increase the concentration of the dioxane. Another use is to dilute sodium hydroxide with a concentration of 45% to a concentration of less than 10% as a formic acid neutralizer in the production of paraformaldehyde to remove formic acid in the system to reduce equipment corrosion. Among them, in the production of dioxane, a large amount of waste lye will be produced, which will be sold at low prices, resulting in huge waste. SUMMARY OF THE INVENTION [0003] The objec...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D323/06C07D317/12
CPCC07D317/12C07D323/06
Inventor 万情操龚光泽陈欣
Owner TIANJIN BOHUA YONGLI CHEM IND
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