Hydrocracking method for producing chemical materials

Abstract

The invention discloses a hydrocracking method for producing chemical materials. The method comprises the steps of: orderly entering material oil and hydrogen into a hydrorefining reactor and a first hydrocracking reactor to react after being mixed; and cooling and separating reactants, and then entering obtained 10-100% of diesel fraction with the temperature of 175-320 DEG C into a second hydrocracking reactor to further react, wherein a hydrocracking catalyst II is a hydrocracking catalyst with low metal content; the metal content of the hydrocracking catalyst II is lower than that of a hydrocracking catalyst I. By adopting the hydrocracking method, the yield and the selectivity of heavy naphtha can be effectively improved; the aromatic latent of the heavy naphtha is improved, and hydrogen consumption is reduced.

Description

technical field [0001] The invention belongs to a method for obtaining cracked hydrocarbon oil in the presence of hydrogen, more specifically, a hydrocracking method for producing chemical raw materials. Background technique [0002] The reforming unit is an important secondary processing unit in a refinery, used to produce high-octane gasoline blending components or to produce aromatic hydrocarbon base materials. Reformed gasoline has the characteristics of high octane number, no olefins, no sulfur and nitrogen impurities, and is a high-quality gasoline blending component. Compared with European and American countries, reformed gasoline components in the current domestic gasoline composition are relatively small, while catalytic cracking gasoline components account for a relatively high proportion, resulting in high sulfur and olefin content in domestic commodity gasoline and relatively low aromatic content; increase gasoline pool The proportion of medium reformed gasoline...

AI Technical Summary

Problems solved by technology

For the hydrocracking unit under the one-pass process, in order to increase the yield of heavy naphtha, the method of increasing the conversion rate can be adopted to convert more heavy fractions into light products, but at the same time it will also lead to the selectivity of heavy naphtha and aroma potential decreased, hydrogen consumption increased

[0005] Adding heavy naphtha can also carry out recycling and refining of all middle distillates. This method can effectively increase the yield of heavy naphtha. Increase the volume space velocity as much as possible, and the high space velocity will affect the long-term operation of the hydrocracking unit. On the other hand, if the volume space velocity is not increased, the volume of the unit and the amount of catalyst will need to be increased, which may not be economically appropriate; more importantly, , not all middle distillates are suitable recycle distillates, and the use of full recycle may reduce the aromatic potential and selectivity of heavy naphtha fractions

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