Two-stage hydrocracking method for increasing yield of middle distillate oil

Abstract

The invention discloses a two-stage hydrocracking operation method to increase the production of high-grade middle distillate oil, which comprises: doping given proportion fresh feed oil in second stage feeding, inhibiting the activity of second-stage catalyst, increasing yield, and enlarging handling capacity. This invention uses one cycle hydrogen system and separation system. Compared with prior art, this inveniton has high yield, well stability, and long running period.

Description

technical field [0001] The invention relates to a two-stage hydrocracking method, in particular to a two-stage hydrocracking method for increasing the production of high-quality middle distillate oil. Background technique [0002] In recent years, the demand structure of the petroleum product market has undergone corresponding changes with the development of the economy. The demand for gasoline, coal and diesel oil, especially middle distillates such as coal and diesel oil, has increased, while the demand for fuel oil has decreased. Crude oil processed by refineries is becoming increasingly heavy, while the quality requirements for engine fuels such as gasoline, coal, and diesel continue to increase, and environmental protection regulations are becoming increasingly stringent. Catalytic cracking, coking and hydrocracking are the three major heavy oil deep processing technologies, among which the products obtained from catalytic cracking and coking cannot be used directly bec...

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Problems solved by technology

[0003] In the two-stage hydrocracking process for the purpose of producing middle distillates, due to the low concentration of organic nitrogen compounds, ammonia, organic sulfur compounds and hydrogen sulfide in the second stage feed, the cracking activity of the catalyst is very high, making The yield of middle distillates cannot be further increased

US3,816,296 has introduced a kind of method that adds ammonia or amine etc. to improve the yield of middle distillate oil in the hydrocracking process, although this method can improve the yield of middle distillate oil, the problem that exists is to increase operating cost, and difficult to control

US6,576,119 introduces a method of contacting the catalyst with ammonia or organic nitrogen compounds at the initial stage of operation to obtain a stable period of hydrocracking operating conditions, suppressing the initial activity of the catalyst, and gradually recovering the activity of the catalyst after the stable period. There is also the problem of high operating costs

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