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Method for refining long-carbon chain dicarboxylic acid

A long-chain dibasic acid and dibasic carboxylic acid technology, which is applied in the separation/purification of carboxylic acid compounds, organic chemistry, etc., can solve the problems of harsh moisture requirements, large steam consumption, acetic acid loss, etc., and reduce the moisture content of raw materials Requirements, the effect of reducing energy consumption

Active Publication Date: 2015-04-08
山东广通新材料有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

It leads to high investment cost of rectification equipment, a large amount of steam is consumed in the process operation, and energy consumption increases
[0016] 2. The moisture requirements in the long-chain dibasic acid crude product to be refined are strict, and the crude product must be dried to a moisture content of ≤4%
[0017] 3. When dibasic acid crystallization is centrifugally filtered, it is washed with water. The content of acetic acid in the washing liquid is about 10%-15%. The recovery cost of this part of dilute acetic acid is extremely high and has no recovery value, resulting in a large loss of acetic acid and increased sewage processing load
[0018] 4. In the dibasic acid after purification and refinement by using acetic acid as a solvent, due to the high boiling point of acetic acid, it is difficult to elute, and there will be a small amount of acetic acid residue, which is not suitable for use as a raw material for synthesizing condensation monomers of polymer materials

Method used

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  • Method for refining long-carbon chain dicarboxylic acid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0073] A kind of refining method of dodecanedioic acid of the present invention

[0074] Add 700kg of dodecanedioic acid (water content 23%) and 4kg of activated carbon into 2000L of acetic acid solution with a purity of 98%, stir and heat up to 95°C, keep warm for half an hour for decolorization, and the dibasic acid solution obtained by plate and frame filtration enters the crystallization kettle , quickly and uniformly cool down to 85°C in the crystallization tank, control the cooling time for 1 hour, turn off the cooling water, and naturally cool down for 1 hour, the temperature in the crystallization tank reaches 80°C, turn on the cooling water and cool down to 25°C, the cooling speed gradually increases from slow, Control the cooling time for 4-5 hours. The crystal liquid is centrifuged and separated, and the material in the centrifuge is rinsed with 1800L of isopropyl acetate with a purity of 98%. After the rinse is completed, it is centrifuged for 15 minutes to obtain ...

example 2

[0076] A kind of recycling method of dodecanedioic acid refining solvent of the present invention

[0077] After mixing the centrifugal mother liquor 1800L obtained in Example 1 and the washing liquid 1750L, feed continuously to the middle part of the rectification column for rectification operation. During the rectification process, the temperature at the top of the tower was controlled at 77°C, and the reflux ratio was 3.2. After the azeotrope extracted from the top of the rectification tower is stratified, 1700L of the oil phase is recycled into the azeotrope storage tank. The measured purity of isopropyl acetate is 97.00%, the water content is 2.48%, and the acetic acid content is 0.52%, which can be continued. Detergent: get 200L of water phase, go to the evaporator for treatment, evaporate 5.8L of azeotrope, return it to the azeotrope storage tank, and the measured cod value of the wastewater in the evaporator is 62. The heavy component of acetic acid in the rectificati...

example 3

[0079] A kind of refining method of dodecanedioic acid of the present invention

[0080] 700kg of dodecanedioic acid (water content 22%) and 4kg of activated carbon were added in the 1780L acetic acid solution obtained in Example 2, stirred and heated up to 95°C, kept for half an hour for decolorization, and the dibasic acid solution obtained by plate and frame filtration entered the crystallization kettle , quickly and uniformly cool down to 85°C in the crystallization tank, control the cooling time for 1 hour, turn off the cooling water, and naturally cool down for 1 hour, the temperature in the crystallization tank reaches 80°C, turn on the cooling water and cool down to 25°C, the cooling speed gradually increases from slow, Control the cooling time for 4-5 hours. The crystallization liquid is centrifuged, and the 1705.8L isopropyl acetate solution recovered by Example 2 is used to rinse the material in the centrifuge. After the rinse is completed, it is centrifuged for 15 ...

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Abstract

The invention relates to a method for refining long-carbon chain dicarboxylic acid. A long-chain dicarboxylic acid crude product prepared by a fermentation method is used as a raw material, acetic acid is used as a solvent, and the refining and purification are performed by recrystallization treatment. The method comprises the process steps of bleaching filtration, cooling crystallization, centrifugal separation, centrifugal material washing, secondary centrifugation and drying, and is characterized in that a. the long-chain dicarboxylic acid crude product to be refined does not need to be dried; b. the acetic acid solvent is recycled by an azeotropic distillation method, and isopropyl acetate is used as an azeotropic dehydrating agent; and c. the isopropyl acetate is used as a centrifugal material washing solvent for replacing the acetic acid. The purification method of the long-carbon chain dicarboxylic acid provided by the invention has the advantages of distillation equipment investment conservation, low operating power consumption, good product color, high purity, high refining yield and low production cost, the long-carbon chain dicarboxylic acid to be refined does not need to be dried and dehydrated, and the acetic acid solvent is completely recyclable. The quality of the refined product can meet the technical requirements of use of condensed monomer raw materials used by synthesis of high polymer materials.

Description

technical field [0001] The invention is a method for refining long carbon chain dicarboxylic acids. It belongs to the purification treatment of acyclic dicarboxylic acids with more than 10 carbon atoms. Background technique [0002] Long-chain dicarboxylic acid (along-chain dicarboxylic acid)—a straight-chain dicarboxylic acid with more than 10 carbon atoms in the carbon chain, is an important class of fine chemical products. Main raw materials for synthesizing polyamide resins, polyester resins, hot melt adhesives, spices, weather-resistant plasticizers, lubricating oil additives, coatings, liquid crystals, etc. [0003] Use long-chain dicarboxylic acids as raw materials to develop plasticizers with excellent performance used in the production of PVC (polyvinyl chloride), such as long-chain dibasic acid dibutanol ester, dihexyl alcohol ester, dioctyl alcohol ester, etc. . Replace existing phthalic acid and aliphatic dibasic acid esters; develop long-chain dibasic acid di...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C55/21C07C55/02C07C51/42C07C51/46
CPCC07C51/42C07C51/43C07C51/46C07C55/21C07C55/02
Inventor 房宁张亮杨光耀
Owner 山东广通新材料有限公司
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