Coal tar hydrogenation system and coal tar hydrogenation method

Abstract

The invention provides a coal tar hydrogenation system and a coal tar hydrogenation method. The method comprises a hydrogenation refining reactor, a separation unit and a hydrogenation cracking reactor, wherein the hydrogenation refining reactor is an up-flow fixed bed reactor, the hydrogenation cracking reactor is a down-flow fixed bed reactor, and the separation unit is a middle liquid separation tank; gas-liquid separation is performed on raw oil and hydrogen after a hydrogenation refining reaction, a part of liquid-phase heavy fractions is separated, one path is used as circulating oil and returned to perform the hydrogenation refining reaction again, and the other path is used as quenching oil after being cooled and added between catalyst bed layers for the hydrogenation refining reaction to play a role of cooling; and the other part of the liquid-phase heavy fractions is used as refined generated oil and mixed with hydrogen to perform a hydrogenation cracking reaction, and the obtained reaction product is combined with gas-phase light fractions after the gas-liquid separation to form the final product. The system and the method provided by the invention are low in equipment cost, simple to operate, capable of prolonging the life of the catalysts of the hydrogenation refining reactor and the hydrogenation cracking reactor, and suitable for raw oil with worse conditions.

Description

technical field [0001] The invention relates to the technical field of processing coal tar by hydrogenation technology, and furthermore, relates to a hydrogenation system and method for producing clean transportation fuels from coal tar. Background technique [0002] With the continuous development of my country's economy, the domestic demand for liquid fuels is increasing day by day. my country's coal reserves are very rich, but oil supply is insufficient. Under the current situation, coal tar, a by-product of coal dry distillation, should be fully utilized, and appropriate processing schemes should be adopted to improve the stability of coal tar, reduce the impurity content in it, and obtain low Sulfur naphtha and clean fuel oil have certain practical significance. The realization of clean and light coal tar can not only meet the needs of national environmental protection regulations, but also improve its economic value, increase economic benefits for enterprises, and effe...

AI Technical Summary

Problems solved by technology

[0010] (5) The content of metals, impurities and residual carbon is very high, which increases the difficulty of processing;

[0011] (6) The content of aromatics is very high, which increases the difficulty of processing;

[0012] (7) The carbon-hydrogen ratio is high, and the degree of unsaturation of raw materials is high, which increases the difficulty of processing

This process cannot dilute the concentration of impurities in the feed oil in the pre-hydrogenation reactor, and the water, ammonia, hydrogen sulfide, etc. generated by the pre-hydrogenation reaction directly contact the main hydrogenation catalyst without removal, affecting the activity of the main hydrogenation catalyst

Therefore, it is not suitable for coal tar raw materials with high impurity content, and the operation period of the device is limited

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