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

Abstract

The invention relates to a coal tar alkali-free normal/reduced-pressure distillation process and a coal tar alkali-free normal/reduced-pressure distillation device. In the process, raw material coal tar is subjected to heat exchange and delivered into a dehydrating tower, and light oil distillate and water are collected from the top of the dehydrating tower; the 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 lateralline; carbon black oil or soft asphalt is collected from the bottom of the tower; bottom material of the main tower is pumped out; part of soft asphalt is pumped out from the bottom of the main towerand delivered to an asphalt tower for distillation under a negative pressure, a heavy oil distillate is collected from a lateral line of the tower, and asphalt is produced at the bottom of the tower;and the main tower is a normal-pressure low-temperature distillate tower, the asphalt tower is a low-temperature reduced-pressure asphalt tower, and all distillates are not added with alkali in the whole flow. In the device, the bottom of the dehydrating tower is connected with the middle of the main tower through a pipe, and the bottom of the main tower is connected with the middle of the asphalt tower through a pipe. The internal circulation at bottom of the main tower is realized through a heating furnace, and internal circulation at the bottom of the asphalt tower is realized through a heating furnace. The process and the device have the advantages that: all distillates are not added with alkali; distillates are cut according to market demands and temperature gradient; direct super-heated steam is not used; new process waste water is avoided; the energy consumption is low; the product quality is high; and the like.

Description

technical field [0001] The present invention relates to the technical field of coal tar processing, and relates to a coal tar distillation process without adding alkali, forced circulation heating of asphalt at the bottom of the tower, atmospheric and vacuum distillation process and fraction cutting sequence, and in particular to a coal tar without adding alkali Atmospheric and vacuum 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 atmosphe...

AI Technical Summary

Problems solved by technology

[0006] 1. In the distillation process, only part of the distillate does not add alkali, most of the distillates are distilled with alkali, but the whole distillate does not have alkali, and the product quality is low

[0007] 2. The order of fraction cutting

Secondly, the asphalt is first cut at high temperature, and then the high-temperature gas phase fraction is quenched and then enters the next tower for distillation. This will inevitably cause high energy consumption of the system, and at the same time, more secondary quinoline insolubles will be produced in the asphalt. Conducive to the secondary processing of asphalt

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