Two-stage slurry bed hydrogenation process of medium and low temperature coal tar

Abstract

The invention provides a two-stage slurry bed hydrogenation process of medium and low temperature coal tar, and the a two-stage slurry bed hydrogenation process comprises the following steps: (1) performing purification on the medium and low temperature coal tar; (2) performing decompression or atmospheric distillation on the medium and low temperature coal tar purified by the step (1) for cutting into light oil fractions and heavy oil fractions, wherein the cutting point temperature range is 320 to 380 DEG; (3) mixing the heavy oil fractions higher than the cutting point of the step (2) with a hydrocracking catalyst and H2, mixing evenly, and in turn getting into a first stage slurry bed and a second slurry bed for two-stage hydrocracking reaction, processing the prepared hydrocracking products by fractionation, performing fractional distillation on the hydrocracking products by the cutting point temperature range in the step (2) to distil off fractions lower than the cutting point; discharging 3-8% fractions higher than 540 DEG C out, and recycling the rest fractions back to a first stage slurry bed reactor. A liquid fuel prepared by the process has the advantages of low hydrogen consumption and high product yield.

Description

technical field [0001] The invention relates to a two-stage slurry bed hydrogenation process for medium and low temperature coal tar, which belongs to the technical field of coal chemical industry. Background technique [0002] Liquid fuels play an important role in various energy sources. Various vehicles, ships, airplanes, construction machinery and other means of transportation all use liquid fuels in large quantities. Liquid fuels are mainly derived from petroleum extracted from the ground. In recent years, with the depletion of world oil resources and the continuous deepening of my country's energy crisis, it has become an urgent task for our country to find reasonable and economical alternative energy sources and change the energy consumption structure. [0003] With the rapid development of my country's steel and coal chemical industries, the output of coal tar is increasing, and the effective utilization of coal tar is becoming more and more important. With coal t...

AI Technical Summary

Problems solved by technology

Although the above-mentioned technology first carries out vacuum or atmospheric pressure distillation to the whole fraction of coal tar, and then separately hydrotreats the obtained light fraction and heavy fraction, but in the above-mentioned technology, when the heavy fraction is carried out catalytic hydrogenation , and dilute the heavy distillate oil with diluent oil first, and then use fixed bed hydrofining for the diluted heavy distillate oil, and the existence of diluent oil will also lead to an increase in hydrogen consumption during the hydrofinishing process, resulting in Waste of resources will also affect the yield of liquid fuels produced by hydrogenation of coal tar

[0007] That is to say, in the prior art, when the heavy distillate in coal tar is subjected to slurry bed or fixed bed hydrogenation reaction, the heavy distillate is diluted with light distillate or diluent oil before hydrogenation reaction, and the inventors have found through research that too much light fraction exists in the heavy fraction, and when the hydrogenation reaction is carried out together with the heavy fraction, there is a high hydrogen consumption, which also leads to the failure of coal tar hydrogenation to prepare liquid fuels Low yield, high S and N content of liquid fuel, especially low cetane number content of the obtained diesel product

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