Method for reducing content of impurities in 2-methylnaphthalene

A technology of impurity content and methyl naphthalene, applied in the field of impurities, can solve the problems of no better impurities, high energy consumption, etc., and achieve the effect of improving quality, high recovery rate and excellent product quality

Active Publication Date: 2009-11-11
BAOWU CHARCOAL MATERIAL TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0010] From the above-mentioned prior art, most of the means of high energy consumption such as distillation are used to obtain 2-methy

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] (1) 765.9 g of 2-methylnaphthalene with a content of 96.26% extracted from coal tar is placed in a crystallizer, and the circulating water gradually heats up, and the temperature of the crystallizer is raised to 65° C., and the heating rate is 3° C. / min , making the 2-methylnaphthalene raw material in the crystallizer all melt;

[0027] (2) After the 2-methylnaphthalene in the crystallizer is completely melted, the circulating water is cooled slowly at a cooling rate of 10°C / h, and the temperature of the crystallizer is cooled to 30.5°C, and the entire cooling and crystallization process lasts for 3 hours;

[0028] (3) discharge uncrystallized material in the crystallizer, duration 2 hours, discharge is 147.4g;

[0029] After the discharge was completed, the temperature of the circulating water was gradually increased to heat the crystallizer to 68° C., so that all the 2-methylnaphthalene in the crystallizer was melted and discharged, and the obtained product was 618.5 ...

Embodiment 2

[0037] (1) 760.8 g of 2-methylnaphthalene with a content of 96.26% extracted from coal tar is placed in a crystallizer, and the circulating heat transfer oil is gradually heated up, and the heating rate is 3 ° C / min, and the temperature of the crystallizer is raised to 68 ℃, so that the 2-methylnaphthalene raw material in the crystallizer is all melted;

[0038] (2) After the 2-methylnaphthalene in the crystallizer is completely melted, the circulating heat transfer oil is cooled slowly at a cooling rate of 9°C / h, and the temperature of the crystallizer is cooled to 30.0°C, and the entire cooling and crystallization process lasts for 4.5 hours;

[0039] (3) discharge uncrystallized material in the crystallizer, duration 2 hours, discharge is 144.4g;

[0040] After the discharge, the circulating heat-conducting oil was gradually heated to raise the temperature of the crystallizer to 70° C., so that all the 2-methylnaphthalene in the crystallizer was melted and discharged, and t...

Embodiment 3

[0048](1) 768.8 g of 2-methylnaphthalene 768.8 g extracted from coal tar with a content of 96.26% is placed in a crystallizer, and the circulating water is heated up gradually at a rate of 4° C. / min, and the crystallizer temperature is raised to 65° C. , making the 2-methylnaphthalene raw material in the crystallizer all melt;

[0049] (2) After the 2-methylnaphthalene in the crystallizer is completely melted, the circulating water cools down slowly at a cooling rate of 13°C / min, the temperature of the crystallizer is cooled to 31.0°C, and the entire cooling and crystallization process lasts for 4 hours;

[0050] (3) discharge uncrystallized material in the crystallizer, duration 2 hours, discharge is 153.3g;

[0051] After the discharge was completed, the temperature of the circulating water was gradually raised to heat the crystallizer to 68° C., so that all the 2-methylnaphthalene in the crystallizer was melted and discharged, and the obtained product was 615.5 g.

[0052]...

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Abstract

The invention discloses a method for reducing the content of impurities in 2-methylnaphthalene. 2-methylnaphthalene which is extracted from coal tar and has the content not lower than 96 percent is used as the raw material. A melt crystallization method is adopted, and the method comprises the following steps: (1) adding the 2-methylnaphthalene raw material in a crystallizer, and gradually raising the temperature of the 2-methylnaphthalene raw material by heating and raising the temperature of the crystallizer to 60-70 DEG C so that the 2-methylnaphthalene raw material in the crystallizer is thoroughly melted;(2) slowly lowering the temperature of the 2-methylnaphthalene raw material after the 2-methylnaphthalene raw material in the crystallizer is thoroughly melted, and cooling the crystallizer to 30-31 DEG C, wherein the whole cooling crystallization process lasts for 3-4.5h; and (3) discharging substances which are not crystallized in the crystallizer, wherein the remaining crystal is the purified 2-methylnaphthalene. The method can effectively reduce the content of such impurities as 1-methylnaphthalene, indole, 2-methyldibenzothiophene, 5-methyldibenzothiophene, and the like in the 2-methylnaphthalene, achieves higher recovery rate and is clean and environment-friendly.

Description

technical field [0001] The invention relates to a method for reducing the impurity content of 2-methylnaphthalene, in particular to a method for removing 1-methylnaphthalene, indole, benzothiophene and other impurities in 2-methylnaphthalene. Background technique [0002] 2-methylnaphthalene (also known as β-methylnaphthalene; English name: 2-methylnaphthalene; molecular formula: C 11 h 10 ; Molecular weight: 142.20; CAS No.: 91-57-6) is an important organic chemical raw material, which can be used to produce textile auxiliaries, lubricants and plant growth regulators. High-purity 2-methylnaphthalene is a synthetic vitamin K Raw materials for drugs and feed additives. With the development of medicine and feed industry in recent years, the quality requirements for 2-methylnaphthalene are getting higher and higher in the world, and the demand is also increasing. [0003] Japan's Kawasaki Iron and Steel Company has built a semi-industrial workshop for the production of 2-met...

Claims

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Application Information

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IPC IPC(8): C07C15/24C07C7/14
Inventor 袁康入
Owner BAOWU CHARCOAL MATERIAL TECH CO LTD
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