Two-stage hydrocarbon hydrogenation method for cracking different fractions of generated oil at refining stage in branches

Abstract

The invention relates to a two-stage hydrocarbon hydrogenation method for cracking different fractions of generated oil at a refining stage in branches. In the method, in the second-stage hydrogenation part, a first-stage hydrogenation generated oil high-boiling fraction (HBO) enters a second-stage first reaction region (2R1) to contact with a first hydrocracking catalyst (2R1C), so that a second-stage first hydrocracking reaction is finished and the HBO is converted into a reaction effluent (2R1P) of the second-stage first reaction region; 2R1P-based material flow and first-stage hydrogenation generated oil low-boiling fraction (LBO)-based material flow contact with a combined hydrocracking catalyst (2RUC) in a second-stage combined hydrocracking reaction region, so that a second-stage combined hydrocracking reaction is finished and a second-stage combined hydrocracking reaction effluent (2RUPM) is obtained; the 2RUPM is separated and products of the 2RUPM are recovered; and other product material flow which may exist in the second-stage hydrogenation part are recovered. The method has the advantages of avoidance of overcracking of the LBO and simple flow and is particularly suitable for the process of producing high-quality diesel components by a two-stage coal tar hydrocracking method.

Description

technical field [0001] The invention relates to a two-stage hydrocarbon hydrogenation method in which different fractions of oil produced in the refining section are cracked separately. In the second-stage hydrogenation reaction part, the high-boiling fraction HBO of the oil produced by hydrogenation in the first stage enters the first reaction zone 2R1 of the second stage and is connected with the first reaction zone 2R1. The hydrocracking catalyst 2R1C is contacted to complete the second-stage first hydrocracking reaction and is transformed into the second-stage first reaction zone reaction effluent 2R1P, and the stream based on 2R1P and the stream based on the low-boiling point fraction LBO of oil generated by the first-stage hydrogenation are combined in the second stage. The hydrocracking reaction zone 2RU is contacted with the combined hydrocracking catalyst 2RUC to complete the two-stage combined hydrocracking reaction, and the second-stage combined hydrocracking reactio...

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Problems solved by technology

[0003] ①According to the joint processing technology plan, the mixture of diesel components and wax oil components in the oil produced by one-stage hydrotreating enters the same cracking reaction zone, and the same hydrocracking catalyst must be used, and it is impossible to treat diesel components and wax oil components at the same time The components constitute the best operating conditions. While completing the hydrocracking of the first-stage hydrorefining to produce oil, the wax oil component is hydrocracked to produce diesel oil, it will inevitably cause the over-cracking of the first-stage hydrorefining to produce oil and diesel components (because the catalyst cracking activity is relatively high, Reaction temperature is relatively high, catalyst space velocity is relatively low), increase additional hydrogen consumption, reduce diesel yield; especially for the case of high yield of diesel components in the oil produced by one-stage hydrotreating (such as medium and low temperature tar hydrotreating produced oil ), this shortcoming is more significant;

[0004] ② According to the independent processing technology plan, build two sets of units, that is, build an independent hydrocracking unit that uses the selective hydrogenation ring-opening method to increase the cetane number of hydrotreated diesel components, and build an independent completion of the wax oil component The hydrocracking unit for hydrocracking to produce diesel oil requires huge engineering investment, especially when the scale of the unit is small, this disadvantage is more significant

[0005] There is no report on the two-stage hydrocarbon hydrogenation method in which different fractions of the oil produced in the hydrofinishing stage are cracked separately in the second stage and combined cracking is completed.

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