Separation purification process for 2-methylnaphthalene

Abstract

The invention relates to a method for separating and purifying 2-methylnaphthalene (Beta-methylnaphthalene). The method comprises the main steps: 70 wt% of 2-methylnaphthalene fraction is used as original material, and is subjected to fused crystallization at 34 DEG C to -15 DEG C for at least four times to obtain a target product. The method has the advantages of easily-accessible material, simple operation, low energy consumption, environment friendliness, etc.

Description

Separation and purification method of 2-methylnaphthalene Technical field The invention relates to a method for separating and purifying 2-methylnaphthalene (also known as β-methylnaphthalene), in particular to a washing oil fraction from coal tar (the content of 2-methylnaphthalene is about 70% by weight) The method for separating and purifying 2-methylnaphthalene. Background technique 2-Methylnaphthalene (β-methylnaphthalene) is an important chemical raw material and intermediate. For example, 2-methylnaphthalene can be used to prepare 2,6-naphthalenedicarboxylic acid (the carboxylic acid is a key component in the production of high-temperature polymers); it is used to synthesize vitamins K1, K3 and K4. In addition, 2-methylnaphthalene can also be used in the production of spices and other fine chemicals. Therefore, its commercial preparation has attracted much attention from chemists. US 3,219,719 discloses a method for isomerizing and purifying 2-methylnaphthalene. Under th...

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Problems solved by technology

The disadvantage of this method is that (1) the starting material is difficult to obtain, (2) when the temperature of the operating environment is high, it is quite difficult to separate the 2-methylnaphthalene crystal from the mother liquor, and it is necessary to reclaim the alcohol simultaneously Also increase investment in equipment

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