Technology for extracting and purifying naphthalene from coal tar

Abstract

The invention relates to a deep processing technology for coal tar, and specifically relates to a technology for extracting and purifying naphthalene from the coal tar. The technology solves the technical problems of utilizing efficiency of the coal tar and purifying and deep processing of the naphthalene, so the technology for extracting and purifying the naphthalene from the coal tar is provided. The technology comprises an alkali washing step, dephenolizing the naphthalene distillation oil through the alkali washing step, and a dehydrating step, heating the material to a temperature between 210-215 DEG C and inputting the material into a primary distillation tower, preliminarily separating the raw material in the primary distillation tower, letting phenol oil to overflow from the top of the primary distillation tower and to enter a condenser for cooling followed by entering an oil-water separator for separating of the water, obtaining the phenol oil and inputting the phenol oil to the primary distillation tower again, letting the naphthalene oil and wash oil fraction distillated from the primary distillation tower to flow to a storage tank at the bottom of the primary distillation tower, and inputting a portion of the oil to a tube heating furnace of the primary distillation tower for heating and returning back to the bottom of the primary distillation tower after the oil is heated; inputting the rest of the oil into a rectifying tower, circulatingly heating the oil in the rectifying tower and a tube heating furnace of the rectifying tower to keep the oil at a temperature of 215-220 DEG C, letting gas naphthalene to overflow from the top of the rectifying tower and to pass through a heat exchanger and a condenser to become a liquid state naphthalene oil, and filling the oil into a collecting groove and sending the oil to a crystallization technology section for processing.

Description

technical field [0001] The invention relates to a coal tar deep processing technology, in particular to a process for extracting and purifying naphthalene from coal tar. Background technique [0002] Shanxi is my country's largest coal-producing province, as well as a coking coal-producing province. The amount of tar produced by coking every year is very large, and the direct discharge of tar without treatment will cause considerable damage to the surrounding environment. Tar contains a large amount of chemical raw materials. If it is further processed, developed and utilized, it can protect the environment, improve economic benefits, and promote enterprise transformation. The composition of coal tar is extremely complex. In most cases, it is used by the coal tar industry after separation and purification. The fractions of tar are further processed and can be separated into a variety of products. They are used for the production of plastics, synthetic fibers, dyes, rubber, m...

AI Technical Summary

Problems solved by technology

[0003] The present invention provides a process for extracting and purifying naphthalene from coal tar in order to solve the technical problems of coal tar utilization efficiency and purification of deep-processing naphthalene

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