Production method for industrial naphthalene

Abstract

The invention belongs to the chemical industry technical field, in particular to a production method for industrial naphthalene. The production method for the industrial naphthalene is as follows: raw material tar tri-mixed fractions are processed in a reduced-pressure distillation step to respectively obtain naphthalene washing fraction and product carbolic oil; after carbolic oil is cooled, a part thereof returns to the reduced-pressure distillation step and participates in backflow; remaining carbolic oil is used as the product to be output; one part in the naphthalene washing fraction returns to the reduced-pressure distillation and serves as the heat source; the remaining naphthalene washing fraction is processed by a rectification step to respectively obtain product naphthalene and washing oil; a part of washing oil returns to the rectification step and serves as the heat source; naphthalene and washing oil respectively exchange heat with the raw material tar tri-mixed fractionsin the reduced-pressure distillation and cool down, and then the product is output. The method can obtain industrial naphthalene with more than 96% purity; after naphthalene is removed, phenol content of washing oil is about 200mg / L and the content of naphthalene is 2500mg / L. The production method has low operational cost, little investment, reduces the separation cost, has high product yield andgood quality, and is beneficial to the further development of follow-up products.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, in particular to a production method of industrial naphthalene. Background technique [0002] At present, the production methods of industrial naphthalene are mainly double-furnace double-tower process and single-furnace single-tower process. The double-furnace double-tower process is suitable for large-scale production and low-naphthalene-containing raw materials. It is the most widely used process in China. Specifically: the naphthalene-containing fraction after static dehydration is pumped from the raw material to the industrial naphthalene heat exchanger , the temperature rises from 80 to 90°C to about 200°C, and enters the initial distillation tower. The phenol oil vapor that escapes from the top of the initial distillation tower enters the reflux tank after being condensed and cooled and separated from oil and water. Most of it is used as the reflux of the initial distillation to...

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Problems solved by technology

This process only uses one heater and one rectification tower, which has the advantages of simple process, easy operation, and advanced technology. However, the single furnace and single tower process requires high naphthalene content in raw materials, and cutting industrial naphthalene from the side line requires a large number of theoretical plates. , the separation efficiency is low, the yield of industrial naphthalene obtained is small, and the naphthalene content is relatively low

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