Descending reactor and riser reactor serially connected catalytic cracking method

Abstract

A catalytic cracking method including a downer reactor and a riser reactor connected with each other in series comprises the follow steps of: injecting preheated raw material oil in the downer reactor to contact a high-temperature regeneration catalyst from a regenerator, vaporizing and cracking, discharging the oil gas from the outlet of the downer reactor to the riser reactor, further reacting, introducing another regeneration catalyst from the inlet of the riser reactor, discharging the oil gas and the catalyst from the outlet of the riser reactor to a settlement separator to separate the oil gas, discharging the separated oil gas to a subsequent fractional distillation system, and stripping the used catalyst separated by the separator and regenerating the catalyst by burning in the regenerator, and circulating the regenerated catalyst to the reactor. According to the different target products, the method provided by the invention can adopt different catalysts and different operation conditions in the riser reactor and the downer reactor. The method can improve the yield of gasoline and improve the product quality.

Description

technical field [0001] The present invention relates to a catalytic cracking method and device for hydrocarbon oil in the absence of hydrogen, more specifically, a method and device for fluidized catalytic cracking of petroleum. Background technique [0002] Fluid catalytic cracking and catalytic cracking are the most important secondary processing methods in the field of petroleum refining. Early fluid catalytic cracking used amorphous microspherical silica-alumina catalysts with low activity and bed reactors. With the emergence of high-activity and high-selectivity molecular sieve catalysts, the riser catalytic cracking process has been greatly developed. Widely used in molecular sieve catalytic cracking. [0003] Due to the continuous increase in crude oil prices, the growing demand for light oil, and the increasingly stringent environmental regulations, the use of catalytic cracking technology to process heavy crude oil to produce cleaner fuel products while reducing th...

AI Technical Summary

Problems solved by technology

In this method, the reactor type is similar to a U-shaped tube. Since the catalyst is not renewed as a regenerant after the reaction in the downlink section is completed, it continues to enter the uplink reaction section together with the reaction materials. In the uplink reaction section, the catalyst activity is the same as the initial The activity has been greatly reduced, which affects the further conversion of raw materials, which increases the impact of thermal cracking reactions, increases the selectivity of product dry gas and coke, and the conversion rate of raw materials is low

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