Low-carbon olefin production method

Abstract

The invention relates to a low-carbon olefin production method. The method comprises the following steps: 1, preheating a cracking substance A containing a cracking raw material and water vapor to a cross-over temperature; 2, allowing hydrogen having an amount being 0.5-1.5% of the weight of the cracking raw material and oxygen having an amount being 2-12% of the weight of the cracking raw material to contact with the preheated cracking substance A in the presence of a hydrogen selective-combustion catalyst under a hydrogen selective-combustion reaction condition to obtain a cracking substance B; and 3, carrying out steam cracking of the cracking substance B obtained in step 2 to obtain a substance C, and carrying out separating recovery of the substance C to obtain low-carbon olefins. The invention also discloses an another low-carbon olefin production method. The another low-carbon olefin production method is carried out in a cracking system comprising a cracking furnace and a cracking gas header tube, and a hydrogen selective-combustion device is arranged at the bottom of the convection zone of the cracking furnace. The low-carbon olefin production methods can prolong the running period of the cracking furnace.

Description

technical field [0001] The invention relates to a method for producing low-carbon olefins. Background technique [0002] Ethylene is a basic raw material for the petrochemical industry. The output, production scale and technology of ethylene indicate the development level of a country's petrochemical industry. At present, the method of producing ethylene is mainly based on tube furnace petroleum hydrocarbon steam cracking technology. According to statistics, about 99% of ethylene and more than 50% of propylene in the world are produced by this method. [0003] The core equipment of the ethylene plant is the tube cracking furnace, which is composed of a convection section and a radiation section. The pyrolysis raw material and dilution water vapor are first heated in the furnace tube of the convection section, the raw material is gasified and heated to the initial cracking temperature (ie "crossover temperature"), and then enters the furnace tube of the radiant section for ...

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Problems solved by technology

[0011] The purpose of the present invention is to overcome the shortcomings of high energy consumption and high heat load passing through the radiant section of the cracking furnace in order to overcome the shortcomings of easy coking in the production of low-carbon olefins by steam cracking, and to provide a low energy consumption and low heat load passing through the radiant section of the cracking furnace. Method for producing low-carbon olefins thereby reducing coking

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