A kind of coal tar hydrogenation treatment method

Abstract

The invention provides a method for hydrogenation treatment of coal tar. The method is that coal tar and hydrogen are first hydrogenated in the fluidized bed reaction zone of a hydrogenation reactor; the reaction product is dehydrated and fractionated to obtain light components and heavy components, which are recombined Partially return to the ebullating bed reaction zone or partly thrown out; light components enter the fixed bed reaction zone of the hydrogenation reactor to react, and the reaction products are fractionated to obtain gas, naphtha and diesel; the hydrogenation reactor is a concentric cylinder Shaped reactor, including inner and outer cylinders, the inner cylinder is the ebullating bed reaction zone, the outer cylinder is the fixed bed reaction zone, the ebullating bed reaction zone and the fixed bed reaction zone are not connected to each other, respectively equipped with inlet feed line and discharge line. The method of the invention can effectively alleviate the temperature rise in the fluidized bed reaction zone, reduce the consumption of quenching oil, and can also save the heating furnace required for hydrogenation in the light component fixed bed reaction zone in the prior art, saving equipment investment.

Description

technical field [0001] The invention relates to a processing method of coal tar, in particular to a method for hydrogenation treatment of coal tar rich in aromatic hydrocarbons and colloids. Background technique [0002] Coal tar is a liquid product obtained during coal dry distillation and gasification. At room temperature, coal tar is a black viscous liquid with a high density. It is mainly composed of polycyclic aromatic compounds. The composition of coal tar is extremely complicated. It has been separated and There are more than 500 species identified. Compared with the petroleum processing process, coal tar is obtained under high temperature conditions, which contains a large amount of unsaturated hydrocarbons such as diolefins, aromatic hydrocarbons and colloids, and the content of saturated hydrocarbons and asphaltenes is relatively small. In some coal tar The sum of aromatic hydrocarbons and colloids can account for more than 90%. These components release a lot of h...

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Problems solved by technology

This production method is a combined process of fixed bed and ebullating bed, but due to the high impurity content in tar, and the reaction at high temperature is easy to coke, resulting in serious blockage of the catalyst bed, to maintain long-term operation, the catalyst needs to be replaced frequently, and the amount of catalyst is large , which increases the cost and complicates the process; in addition, this process cuts off the light components first, which makes the raw material properties heavier in a disguised form, and actually processes the heavy components in coal tar

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