Method for extracting high-purity 2-methylnaphthalene from wash oil

Abstract

The invention provides a method for extracting high-purity 2-methylnaphthalene from wash oil. The method comprises the following steps: rectifying and separating the wash oil to obtain a methylnaphthalene-enriched fraction; introducing the methylnaphthalene enriched fraction into an azeotropic distillation tower for azeotropic distillation to obtain an azeotropic distillate; introducing the azeotropic distillate into a separator to obtain a 2-methylnaphthalene crude product; and introducing the 2-methylnaphthalene crude product into a plurality of intermittent melt crystallizers which are arranged in parallel, and crystallizing and purifying the 2-methylnaphthalene. According to the method, the entrainer is recovered by adopting a water extraction and ultrasonic mixing combined method, so that the cost is low, the technical process is simple, the impurity content in the entrainer is low, and the entrainment amount of the entrainer in the 2-methylnaphthalene crude product is low. The process disclosed by the invention realizes continuous operation, is high in production efficiency and low in operation cost, does not involve strong acid and strong alkali, and is pollution-free, green and environment-friendly in the process. The 2-methylnaphthalene is extracted through azeotropic distillation and melt crystallization, and the obtained product is high in purity and high in yield.

Description

technical field [0001] The invention belongs to the technical field of separation and purification of fine chemicals, and in particular relates to a method for extracting 2-methylnaphthalene based on azeotropic distillation and melt crystallization. Background technique [0002] 2-Methylnaphthalene, also known as β-methylnaphthalene, is an important fine chemical and organic chemical raw material with a wide range of uses. 2-Methylnaphthalene is mainly derived from coal tar wash oil fraction, petroleum cracking by-product tar, and heavy aromatics. It is widely used in industries such as medicine, dyes, photosensitive materials, rubber, plastics, agricultural feed, and new polymer materials. 2-Methylnaphthalene can be used to produce fine chemical products such as vitamin K, textile auxiliaries, water reducers, plant growth regulators, surfactants, lubricants and feed additives. [0003] Due to the complexity of the washing oil fraction of coal tar, it is difficult to obtain...

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Problems solved by technology

[0007] The object of the present invention is to provide a kind of method that extracts high-purity 2-methylnaphthalene from coal tar washing oil, to solve the existing 2-methylnaphthalene separation and refining process, the production efficiency is low, complex process, product purity and Problems such as low yield, serious pollution and equipment corrosion

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