A method and system for preparing low-carbon olefins

Abstract

The invention relates to a method and system for preparing low-carbon olefins. The method is carried out as follows: the crude oil is sent to the first tube group of the convection section of the cracking furnace for preheating, and then vapor-liquid separation is performed to form a first vapor phase and a first liquid phase. phase; the first liquid phase is sent to the first tube group of the convection section for preheating, and the preheated first liquid phase is distilled to form a tower top fraction, a middle distillate and a tower bottom fraction; the tower bottom fraction is subjected to hydroprocessing , to obtain circulating hydrogen, light components after hydrogenation and heavy components after hydrogenation; mix the top distillate with the middle distillate, mix with the first vapor phase, and light components after hydrogenation, and send them to the cracking furnace for cracking to obtain a low carbon olefins. The present invention adopts the combination of cracking furnace, vapor-liquid separation unit, distillation unit and hydroprocessing unit, which can effectively solve the problems that the heavy cracking raw material cannot be fully gasified in the convection section and is easy to coke in the radiation section and the quenching section.

Description

technical field [0001] The invention relates to the field of preparation of low-carbon olefins, in particular to a preparation method and system of low-carbon olefins. Background technique [0002] Low-carbon olefins generally refer to the general term for unsaturated hydrocarbons with carbon 4 and below, mainly including ethylene, propylene, isobutylene, butadiene and other organic chemical raw materials with high economic value. With the development of my country's economy, the demand for these organic chemical raw materials is increasing year by year. Although the production scale of low-carbon olefins is also increasing year by year, it cannot meet the increasing demand. [0003] For a long time, my country has been preparing low-carbon olefin products from naphtha. However, in recent years, with the massive exploitation of associated gas in Middle East oilfields and shale gas in the United States, these cheap oil and gas resources have been widely used as ethylene raw ...

AI Technical Summary

Problems solved by technology

[0010] The purpose of the present invention is to provide a method and system for preparing low-carbon olefins in order to overcome the problems of insufficient crude oil vaporization, easy coking in the cracking process, and low yield of low-carbon olefins in the prior art. Improve the cracking efficiency of crude oil raw materials, prolong the operation cycle, reduce the coking phenomenon during cracking, and increase the yield of low-carbon olefins in the product at the same time

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