A Catalytic Cracking Method for Improving Heat Distribution

Abstract

The present invention relates to a catalytic cracking method for improving heat distribution, the method comprising: (1), feeding catalytic cracking feedstock oil into the first reaction zone of a catalytic cracking reactor to contact with a catalytic cracking catalyst and performing the first catalytic cracking reaction (2), continuing the second catalytic cracking reaction in the second reaction zone of the catalytic cracking reactor with the first reaction product and the half spent catalyst of the gained, to obtain the second reaction product and the spent catalyst; into the second reaction zone of the catalytic cracking reactor to contact with the first reaction product and the half spent catalyst and carry out the second catalytic cracking reaction together. The method of the invention can improve the heat distribution of the catalytic cracking reactor and improve the distribution of reaction products.

Description

technical field [0001] The invention relates to a catalytic cracking method for improving heat distribution. Background technique [0002] Low carbon olefins (C 2 -C 4 Olefins) as basic organic chemical raw materials play a pivotal role in modern petroleum and chemical industries, especially ethylene and propylene. The methods for preparing low-carbon olefins can be roughly divided into two categories, namely traditional petroleum routes and emerging non-petroleum routes. The traditional methods of producing light olefins from petroleum are mainly steam cracking and catalytic cracking processes. Since the 10s of the 20th century, countries around the world have been devoting themselves to the research and development of routes to produce low-carbon olefins from non-petroleum resources, and some progress has been made. [0003] Chinese patent CN92109905 discloses a catalyst and reaction process for converting methanol into light olefins, a ZSM-5 zeolite catalyst containin...

AI Technical Summary

Problems solved by technology

However, due to the slow heat transfer of the fixed-bed reactor, the reaction of methanol to light olefins is a strong exothermic reaction, which is prone to hot spots, causing damage to the device

[0004] Chinese patent CN200810043239.1 discloses a method for producing low-carbon olefins from methanol, which mainly solves the problem of low selectivity of target products in the process of producing low-carbon olefins from methanol

[0014] The heat required by the reactor is mainly provided by the recycled hot regenerated catalyst. In order to increase the reaction temperature, this purpose can only be achieved by increasing the heat at the bottom of the riser, but the disadvantage is that the contact temperature of the agent oil is too high, or If the solvent-to-oil ratio is too large, the yield of dry gas and coke will increase significantly, and the distribution of products will become poor.

In addition, due to the heat dissipation of the riser reactor, the vaporization of raw materials, and the reaction of hydrocarbons, the temperature of the riser reactor decreases significantly with the increase of the riser height, especially when the riser with variable diameter is used, the temperature of the second reaction is lower than that of the first reaction. 10-15°C, unfavorable for the cracking reaction of the second reaction

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