Hydrofining method of crude 2, 6-naphthalic acid

A naphthalene dicarboxylic acid, hydrogenation refining technology, applied in the direction of carboxylate preparation, chemical instruments and methods, preparation of organic compounds, etc., can solve the problem of high naphthalene production

Pending Publication Date: 2022-05-03
CHINA PETROLEUM & CHEM CORP +1
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] The technical problem to be solved by the present invention is the problem that the impurity 2,6-dicarboxy-1,2,3,4-tetrahydronaphthalene is produced in a large amount during the hydrogenation refining process of crude 2,6-naphthalene dicarboxylic acid in the prior art

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  • Hydrofining method of crude 2, 6-naphthalic acid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] 1. Preparation of crude 2,6-naphthalenedicarboxylic acid samples

[0034] 311.25g Co(OAc) 2 ·4H 2 O, 306.25g Mn(OAc) 2 ·4H 2 O, 297.5g KBr, 367.5g CH 3 COOK and 7760g acetic acid are mixed and added in the reactor, then open and stir and be warming up to 185 ℃, the reactor pressure is controlled at 2.75MPa, 1000g 2,6-diisopropylnaphthalene is first warming up to molten state, then with 6g / min The speed enters the reaction kettle, and at the same time, a sufficient amount of air is introduced for the reaction. After the feeding is completed, the reaction temperature and pressure are maintained to continue the reaction for 1 h. Filter, and respectively adopt 60 ℃ of acetic acid washing, 80 ℃ of water washing, the consumption of washing acetic acid is 1000g, and the consumption of washing water is 1000g, after sampling and drying, analyze the impurities 2-formyl-6-naphthoic acid and 2-acetyl- 6-naphthoic acid content. After analysis, the content of 2-formyl-6-naphtho...

Embodiment 2

[0041] 1. Preparation of crude 2,6-naphthalenedicarboxylic acid samples

[0042] 311.25g Co(OAc) 2 ·4H 2 O, 306.25g Mn(OAc) 2 ·4H 2 O, 297.5g KBr, 367.5g CH 3 COOK and 7760g acetic acid are mixed and added in the reactor, then open and stir and be warming up to 185 ℃, the reactor pressure is controlled at 2.75MPa, 1000g 2,6-diisopropylnaphthalene is first warming up to molten state, then with 6g / min The rate enters the reaction kettle, and at the same time, a sufficient amount of air is introduced for the reaction. After the feeding is completed, the reaction temperature and pressure are maintained to continue the reaction for 1 h. Filter, and adopt 60 ℃ of acetic acid washing respectively, 80 ℃ of water washing, the consumption of washing acetic acid is 1000g, the consumption of washing water is 1000g, after sampling and drying, analyze the impurities 2-formyl-6-naphthoic acid and 2-acetyl- 6-naphthoic acid content. After analysis, the content of 2-formyl-6-naphthoic ac...

Embodiment 3

[0049] 1. Preparation of crude 2,6-naphthalenedicarboxylic acid samples

[0050] 311.25g Co(OAc) 2 ·4H 2 O, 306.25g Mn(OAc) 2 ·4H 2 O, 297.5g KBr, 367.5g CH 3 COOK and 7760g acetic acid are mixed and added in the reactor, then open and stir and be warming up to 185 ℃, the reactor pressure is controlled at 2.75MPa, 1000g 2,6-diisopropylnaphthalene is first warming up to molten state, then with 6g / min The rate enters the reaction kettle, and at the same time, a sufficient amount of air is introduced for the reaction. After the feeding is completed, the reaction temperature and pressure are maintained to continue the reaction for 1 h. Filter, and adopt 60 ℃ of acetic acid washing respectively, 80 ℃ of water washing, the consumption of washing acetic acid is 1000g, the consumption of washing water is 1000g, after sampling and drying, analyze the impurities 2-formyl-6-naphthoic acid and 2-acetyl- 6-naphthoic acid content. After analysis, the content of 2-formyl-6-naphthoic ac...

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Abstract

The invention relates to a hydrofining method of crude 2, 6-naphthalic acid, and mainly solves the problem that in the prior art, during hydrofining of crude 2, 6-naphthalic acid, a large amount of impurity 2, 6-dicarboxyl-1, 2, 3, 4-tetrahydronaphthalene is generated. The crude 2, 6-naphthalic acid hydrofining method comprises the following steps: in the presence of a hydrofining catalyst, water is taken as a solvent, crude 2, 6-naphthalic acid reacts with hydrogen to obtain refined 2, 6-naphthalic acid, the catalyst comprises a carrier and a noble metal loaded on the carrier, the noble metal comprises palladium, and the noble metal comprises palladium. The average grain size of palladium is 2-5nm through X-ray diffraction analysis, so that the problem is well solved, and the method can be used for producing refined 2, 6-naphthalic acid.

Description

technical field [0001] The present invention relates to a hydrorefining method of crude 2,6-naphthalenedicarboxylic acid. Background technique [0002] At present, 2,6-NDA is mainly synthesized by air-liquid phase oxidation of dialkylnaphthalene under Co-Mn-Br catalyst in industry, especially the synthesis route using 2,6-dimethylnaphthalene as raw material is the most common, such as US Patent US 5183933 (titled: Process for preparing 2,6-naphthalene-dicarboxylic acid) uses 2,6-dimethylnaphthalene (2,6-DMN) to prepare 2,6-NDA in 93% yield. However, due to the similar physical and chemical properties of 2,6-dimethylnaphthalene and 2,7-dimethylnaphthalene, separation is difficult, resulting in high cost to obtain high-purity 2,6-dimethylnaphthalene ; In contrast, 2,6-diisopropylnaphthalene (2,6-DIPN) is easy to separate and purify from the raw material (isomer mixture), and the operating cost is relatively low, but there are many oxidation by-products, and the subsequent Th...

Claims

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Application Information

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IPC IPC(8): C07C51/487C07C51/265C07C63/38B01J23/44B01J37/02B01J37/18
CPCC07C51/487C07C51/265B01J23/44B01J37/0201B01J37/18B01J35/393B01J35/23C07C63/38
Inventor 朱庆才张海涛司丹
Owner CHINA PETROLEUM & CHEM CORP
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