Coal tar alkali-free short-flow normal/reduced-pressure distillation process and device

Abstract

The invention relates to a coal tar alkali-free short-flow normal/reduced-pressure distillation process and a coal tar alkali-free short-flow normal/reduced-pressure distillation device. In the process, raw material coal tar is subjected to heat exchange and delivered to a dehydrating tower, and light oil distillate and water are collected from the top of the dehydrating tower; coal tar at the bottom of the dehydrating tower is subjected to heat exchange and delivered to a main tower, and a carbolic oil distillate is collected from the top of the main tower; a mixed oil distillate is collected from a lateral line; soft asphalt or carbon black oil is collected from the bottom of the tower; and the bottom material of the main tower is pumped out, heated and returned to the bottom of the main tower to serve as a heat source for the main tower. Normal-temperature operation is adopted in the dehydrating tower, normal-pressure or reduced-pressure operation is adopted in the main tower, and all distillates are not added with alkali in the whole flow. The device comprises the dehydrating tower, the main tower and a heating furnace, wherein the bottom of the dehydrating tower is connected with the middle of the main tower through a pipe; the bottom of the main tower is connected with a soft asphalt or carbon black oil pipe; the middle of the main tower is connected with a mixed oil pipe; and the top of the main tower is connected with a carbolic oil pipe. The process and the device have the advantages that: the flow is short; alkali is not added; direct super-heated steam is not used; new process waste water is avoided; energy consumption is low; product quality is high; and the like.

Description

technical field [0001] The invention relates to the technical field of coal tar processing, and relates to a tar distillation process of coal tar distillation without adding alkali, forced circulation heating of asphalt at the bottom of the tower, and a short distillation process, in particular to a coal tar short process without adding alkali under normal pressure (or Decompression) distillation process and equipment. Background technique [0002] Coal tar is a by-product of the coking process, which is condensed from coking gas. There are nearly 10,000 kinds of organic compounds contained in coal tar, most of which are aromatic compounds, which are important chemical raw materials. At present, the output of coal tar in the world is more than 20 million tons. Usually, coal tar is first divided into light oil, phenol oil, naphthalene oil, wash oil, anthracene oil and asphalt by distillation, and then refined. Typical tar continuous distillation processes include atmospher...

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Problems solved by technology

[0003] Because there are corrosive media such as ammonium salts in the tar, the traditional coal tar distillation process needs to add alkali. Although the corrosion problem is solved, the quality and use of the product are greatly affect

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