Catalytic cracking method

Abstract

The invention discloses a catalytic cracking method. The method comprises the following steps: two descendent tube reactors capable of multipoint feeding are adopted to respectively perform heavy oil catalytic cracking and light hydrocarbon catalytic reforming; two reactant streams flow into a precipitator and are respectively subjected to gas-solid separation by different cyclone separators; a mixed regenerative agent is subjected to steam stripping, enters a multipoint-air-intake riser regenerator to be mixed with a regenerated catalyst stream to perform charring regeneration; the generated semi-regenerated catalyst enters a turbulent bed regenerator to be subjected to charring regeneration; the regenerated catalyst returns to the two reactors for cyclic use; and heavy oil reaction oil gas and light hydrocarbon reaction oil gas are respectively fractionated by the respective special fractionating towers. The method can improve the catalytic cracking product distribution, enhance the light oil yield and lower the yield of the cracked gas and coke; the method can be used for producing low-olefin-content catalytic gasoline and high-cetane-number catalytic diesel; and the method enhances the charring efficiency and decelerates the hydrothermal inactivation of the catalyst.

Description

Technical field [0001] The invention belongs to the field of catalytic cracking of hydrocarbon oil in the absence of hydrogen, and particularly relates to a catalytic cracking method. Background technique [0002] At present, although the equipment used in the catalytic cracking process of the petrochemical industry is diverse, the process form of the reaction regeneration system is basically the same. Most of them use a single riser reactor (or a combination of a single riser and a fast bed). Sectional reactor) and turbulent bed regenerator (or a two-stage regenerator combining turbulent bed and fast bed). The catalyst and the feed oil are contacted and mixed at the bottom of the riser and then reacted upward along the riser. The reactant stream enters the settler from the top outlet of the riser to separate the reaction oil and gas and the catalyst; the separated spent catalyst is subjected to a regular stripping in the stripping section. Enter the regenerator to burn and rege...

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Problems solved by technology

[0008] The invention provides a catalytic cracking method suitable for processing residual carbon less than 0.5% by weight, so as to overcome the high contact temperature between the regenerated catalyst and raw oil, low ratio of agent to oil, long reaction time, and reaction problems existing in the existing catalytic cracking process. Disadvantages such as severe back-mixing of the catalyst in the tank, low regeneration efficiency, and the inability to upgrade catalytic gasoline independently

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