Preparation method of catalytic cracking gasoline octane number additive

Abstract

The invention discloses a preparation method of an octane number additive for catalytically cracked gasoline. By controlling the number of acidic centers on the outer surface of the ZSM-5, using a low-activity matrix and reducing pore channel blockage caused by green coke, the prepared octane number additive has the advantages of low liquefied gas growth rate and high isomerization and aromatization capabilities, and can obviously improve the octane number of gasoline.

Description

technical field [0001] The invention belongs to the technical field of catalysts, and in particular relates to a preparation method of a catalytic cracking gasoline octane number assistant. Background technique [0002] The octane number of gasoline is an important indicator to measure the gasoline used in vehicles. If it does not meet the standard, the gasoline may explode in the cylinder, the vibration of the machine will increase, the output power will be reduced, and the parts will be damaged. In my country, 70% of gasoline comes from catalytic cracking units in refineries, but the octane number of gasoline is low. In order to pursue higher octane number of gasoline, high temperature and short contact operation can be used or catalysts containing ultra-stable molecular sieves can be used. It can also be achieved by using the ZSM-5 octane number additive with high silicon-aluminum ratio, and there have been a lot of patent reports. [0003] Patent CN111686790A introduces ...

AI Technical Summary

Problems solved by technology

(1) poor selectivity

The octane number is still increased by cracking the linear components of gasoline, and the yield of liquefied gas is increased at the same time: (2) It is easy to be poisoned and deactivated, and the number of acid centers of ZSM-5 molecular sieve with high silicon-aluminum ratio is relatively small. After the acid is destroyed, it loses its original function; (3) The pores are prone to carbon deposition and deactivation. The additive itself is a particle with a diameter of 60 μm to 90 μm that is sprayed after mixing the components. Therefore, it is necessary to ensure that the pores are unblocked, so that gasoline molecules can enter the interior of the particles, and make full use of the cracking performance of more ZSM-5 molecular sieves

If there are too many cracking reactions on the outer surface of the matrix or components, carbon will be deposited rapidly, blocking the pores, and reducing the utilization rate of the overall active components

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