Three-tower type atmospheric-vacuum tar distillation process

Abstract

The invention relates to a three-tower type atmospheric-vacuum tar distillation process. A raw material tar is dehydrated to obtain light oil fractions under constant pressure in a pre-dehydrating tower and a dehydrating tower, carrying out constant pressure operation in a No. 1 distillation tower to obtain carbolic oil and naphthalene oil fractions, and carrying out reduced pressure operation in a No. 2 distillation tower to obtain washing oil, primary anthracene oil, secondary anthracene oil and medium-temperature asphalt under or obtain the washing oil, the primary anthracene oil and maltha products. Heats of the pre-dehydrating tower and the dehydrating tower are provided by heat-conduction oil or steam; the heat of the No. 1 distillation tower is circularly provided by tower bottom mixing oil in a No. 1 tube-type heating furnace; and the heat of the No. 2 distillation tower is circularly provided by tower bottom asphalt in a No. 2 tube-type heating furnace. A main device comprises the dehydrating tower, the No. 1 distillation tower, the No. 2 distillation tower, a dehydrating tower reboiler, the No. 1 tube-type heating furnace, the No. 2 tube-type heating furnace, each fraction heat exchanger, a cooler, a pump and the like. The three-tower type atmospheric-vacuum tar distillation process disclosed by the invention has the advantages of being simple and quick in process flow, simple and convenient in operation, low in capital construction investment, energy-saving and environment-friendly, and is suitable for coal tar processing engineering capable of annularly processing anhydrous tar in the scale of more than 2,000,000 tons.

Description

technical field [0001] The invention relates to the technical field of coal tar processing technology in the metallurgical coking industry, and relates to a process and equipment for separating tar from various fractions and soft asphalt or medium-temperature asphalt by distillation, and is especially suitable for large and medium-sized coal tar processing projects. Background technique [0002] The composition of coal tar is extremely complex, including tens of thousands of components such as aromatic hydrocarbons and heterocyclic compounds, and there are more than 200 kinds of products that can be processed. Among them, aromatic hydrocarbons such as naphthalene, anthracene, and phenanthrene, heterocyclic compounds such as thiophene, indole, pyridine, and quinoline, and phenols are unique and very scarce chemical products in coal tar. Coal tar processing is composed of two parts: rough separation and deep processing. The first step of rough separation is tar distillation, s...

AI Technical Summary

Problems solved by technology

The two distillation towers are operated under reduced pressure, which effectively reduces the operating temperature, but the two sets of vacuum systems increase the difficulty of operation, especially the vacuum system corresponding to the 1# distillation tower, due to the existence of naphthalene components, the equipment and pipelines are easy to blockage, hindering the continuous operation of the system

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