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A method for separating and reusing acrolein in the process of preparing 1,3-propanediol

A technology for acrolein and hydroxypropionaldehyde, which is applied in the chemical industry, can solve the problems affecting the selectivity and service life of hydrogenation catalysts, and achieve the effects of uniform material distribution and heat transfer, high reaction efficiency and convenient operation.

Active Publication Date: 2022-07-08
ZHEJIANG HENGYI PETROCHEMICAL RES INST CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The inventors found in the research on the hydration and hydrogenation of acrolein to produce 1,3-propanediol that after the hydration reaction, an aqueous solution of acrolein, 3-hydroxypropionaldehyde and a small amount of acetaldehyde will be obtained. If acrolein and 3-hydroxypropionaldehyde cannot be Complete separation of propionaldehyde will affect the selectivity and service life of subsequent hydrogenation catalysts; if acrolein and acetaldehyde cannot be completely separated, acetaldehyde will continue to accumulate in the hydration system with the reuse of acrolein, thus affecting the hydration reaction The selectivity and service life of the catalyst

Method used

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  • A method for separating and reusing acrolein in the process of preparing 1,3-propanediol
  • A method for separating and reusing acrolein in the process of preparing 1,3-propanediol
  • A method for separating and reusing acrolein in the process of preparing 1,3-propanediol

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Embodiment 1

[0107] use figure 1 Shown process: in the seasoning tank, add 0.1 wt % polymerization inhibitor hydroquinone to 15 wt % acrolein solution to obtain a raw material liquid for hydration reaction; pass the raw material liquid into a hydration reactor, 45 ~ Hydration reaction at 55°C; the reaction product containing acrolein, water, 3-hydroxypropionaldehyde and acetaldehyde is discharged from the upper end of the hydration reactor, and enters the acrolein rectifying tower to separate acrolein and 3-hydroxypropionaldehyde, and acrolein The column top pressure of the rectifying tower is 18~20kPa(A), the column top temperature is 55~60℃, and the tower kettle temperature is 63~70℃; The bottom of the distillation column is discharged into the subsequent hydrogenation reaction unit; the separated steam is discharged from the top of the column, mixed with the polymerization inhibitor solution containing 0.05wt% acrolein steam and atomized, and then subjected to two-stage condensation (t...

Embodiment 2

[0129] and figure 1 The process shown is the same: acrolein raw material, water and 0.1% polymerization inhibitor solution are mixed into a 15% acrolein solution in the mixing tank, pumped into the lower end of the hydration reactor, discharged from the upper end after the reaction, and discharged from the upper end of the tower. The upper part enters the acrolein distillation column. Control tower top pressure 18~20kPa(A), tower top temperature 55~60℃, tower kettle temperature 63~70℃. The output of the tower kettle is 3-hydroxypropionaldehyde solution, wherein the content of acrolein is 37ppm. 77% of the top vapor of the tower is condensed, part of it is returned to the tower, part of it is pumped into the mixing tank for batching, and 23% of the gas is directly fed from the middle of the acrolein recovery tower through a vacuum pump, and the content of acetaldehyde is 5%. The (mass) flow rate is 240kg / h, the number of theoretical plates is 15, the material is fed from the...

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Abstract

The invention relates to the field of chemical industry, and discloses a method for separating and reusing acrolein in the process of preparing 1,3-propylene glycol. The method includes: adding a polymerization inhibitor to an acrolein solution to carry out a hydration reaction; Separating acrolein and 3-hydroxypropionaldehyde; 3-hydroxypropionaldehyde solution enters the hydrogenation reaction unit; after the steam is discharged, it is mixed with the polymerization inhibitor solution and atomized, and then condensed in two stages, and the condensate is partially refluxed to acrolein rectification The tower is partly used for batching, and the non-condensable gas is vacuumed out and incorporated into the polymerization inhibitor, and then enters the acrolein recovery tower in the gas phase state; after stripping, the acrolein aqueous solution is continuously discharged from the tower kettle for batching, and the acetaldehyde liquid is discharged from the tower. The top is extracted and collected after condensation. The method of the invention adopts a rectifying tower to separate 3-hydroxypropionaldehyde, so that it can meet the requirements of the subsequent hydrogenation reaction, and the steam stripping method is applied to the separation of acetaldehyde and acrolein, which can completely separate the entrained acetaldehyde, which is convenient for propylene Recycling of aldehyde solutions.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a method for separating and reusing acrolein in the process of preparing 1,3-propanediol. Background technique [0002] The main use of 1,3-propanediol (1,3-PDO) is as a monomer and terephthalic acid to synthesize a new type of polyester material - polytrimethylene terephthalate (PTT). It can also be used as a solvent, antifreeze Agents, plasticizers, emulsifiers, preservatives or protective agents, etc., can also be used in the synthesis of medicines and as intermediates in organic synthesis. PTT fibers have the advantages of high elastic recovery ability, good colorability, resistance to internal stress, low water adsorption, low static electricity, good biodegradation, and recyclability, showing broad application prospects. Therefore, 1,3-propanediol also has a good market prospect. [0003] At this stage, the production technology of 1, 3-propanediol mainly includes chemica...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C45/64C07C45/82C07C47/19C07C47/22
CPCC07C45/64C07C45/82C07C47/19C07C47/22Y02P20/10
Inventor 柳铭轩张保勇彭华峰贾振宇冯连芳
Owner ZHEJIANG HENGYI PETROCHEMICAL RES INST CO LTD