Catalytic cracking reaction device fed with combination of light raw materials and heavy oil

Abstract

Disclosed is a catalytic cracking reaction device fed with combination of light raw materials and heavy oil. The light raw materials and the heavy oil are fed into a riser reactor with an expanding dense-phase fluidizing section from different positions, are in contact with catalysts and are reacted with the catalysts, oil gas is separated from the catalysts in an upper precipitator of a riser by a cyclone separator, and is exhausted from a reaction system, and deactivated catalysts are fed into a regenerator via a spent inclined tube, are burned and regenerated, then are fed into a pre-riser via a regenerated inclined tube, are lifted by pre-rising media and are fed into the dense-phase fluidizing phase again. A part of the pre-riser is inserted into the expanding dense-phase fluidizing section and is positioned on the same axis with the riser reactor. Heavy oil nozzles are arranged above an outlet at the upper end of the pre-riser, and a distributing plate and an annular feeding tube are sequentially arranged in space between the outlet and the bottom of the expanding dense-phase fluidizing section from top to bottom. The device is used for catalytic cracking reaction of light oil and heavy oil, is beneficial to improving contact of the oil gas and the catalysts, and is high in catalytic conversion efficiency, generated cracking dry gas is reduced, and yield of propylene is increased.

Description

technical field [0001] The invention relates to a catalytic cracking reaction device for combined feeding of light and heavy raw materials, in particular to a combined feeding reaction device for light and heavy raw materials that improves the conversion efficiency of catalytic cracking of mixed C4 and light gasoline. Background technique [0002] The advantages of catalytic cracking of heavy oil to produce propylene are as follows: ①The raw materials come from a wide range of sources, such as wax oil or normal residue; The gasoline produced by the process has a high octane number, and RON can reach about 96; ③Compared with naphtha steam cracking, catalytic cracking of heavy oil has lower reaction temperature, less water vapor consumption and no cryogenic separation, so energy consumption is low. Representative technologies for heavy oil catalytic cracking to produce more propylene include TMP (two-stage riser catalytic cracking technology for producing more propylene) and D...

AI Technical Summary

Problems solved by technology

However, for large-scale catalytic cracking units above 0.5Mt / a, especially above 1.0Mt / a, due to the large diameter of the feed section of light raw materials, the reactor with the above structure is used, although the fluidized density of the catalyst can be adjusted according to the needs. By adjusting the gas velocity to reach 200kg / m 3 Even higher levels, however, are limited by the loop feeding method with small nozzles spraying upwards, which is very prone to channeling, especially in order to recover low-temperature heat and reduce the gasification consumption of light raw materials in the reactor The heat at high temperature is used to reduce the energy consumption of the device, and the light raw material is exchanged with the oil and gas at low temperature. The light raw material is changed from liquid phase feed to gas phase feed, and the channeling phenomenon is more serious

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