A slurry bed and fixed bed serial hydrogenation process of coal tar

Abstract

The present invention provides a coal tar slurry bed and fixed bed series connection hydrogenation process, which comprises: (1) carrying out a purification treatment; (2) carrying out pressure reducing or normal pressure distillation on the purified coal tar, and cutting into the light oil distillate and the heavy oil distillate, wherein the cutting point of the light-heavy oil distillate is 220-370 DEG C; (3) mixing the light oil distillate and H2, uniformly mixing, conveying the obtained material into a fixed bed, and carrying out hydrorefining under the hydrorefining catalyst effect to prepare a hydrorefining product; and (4) mixing the heavy oil distillate, a hydrocracking catalyst and H2, uniformly mixing, sequentially conveying the obtained material into a first-stage slurry bed and a second-stage slurry bed to carry out a double-stage hydrocracking reaction, and carrying out a fractionation treatment on the prepared hydrocracking product, wherein the distillate with the boiling point of more than 540 DEG C is externally discharged, the distillate with the boiling point of less than 350 DEG C is recycled as part of the fed material of the fixed bed, and the remaining components return to the first-stage slurry bed inlet. With the method of the present invention, the sulfur content and the nitrogen content in naphtha and diesel fuel are reduced, and the cetane number in the diesel fuel is substantially improved.

Description

technical field [0001] The invention relates to a coal tar slurry bed and fixed bed combined hydrogenation process, 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] In the prior art, with the rapid development of my country's iron and 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. Wi...

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Problems solved by technology

[0009] The technical problem to be solved by the present invention is that when coal tar is catalytically hydrogenated in the prior art, it is necessary to use light fractions or diluents to dilute the heavy fractions before hydrogenation, which will reduce the concentration of reactants, resulting in In the process of catalytic hydrogenation, the hydrogen consumption increases, the yield of liquid fuel is low, and the product quality is low. Then, through reasonable parameter adjustment, the optimal cut point of light and heavy fractions is creatively selected, thus providing a slurry of coal tar state-bed and fixed-bed hydrogenation process in series; further, aiming at the problems of high hydrogen consumption in the current coal tar hydrogenation process and the unreasonable utilization of hydrogen in the gas separated from each equipment, another coal tar hydrogenation process is provided Slurry bed and fixed bed series hydrogenation process

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