Intercooling separation device and process for catalytic cracking product gas

Abstract

The invention discloses an intercooling separation device and process for catalytic cracking product gas, and is applied to the technical field of product gas separation of catalytic cracking devices.The process comprises the following steps that product gas subjected to compression, impurity removal and other treatment enters a deethanizer after being precooled and segregated, the pressure of the deethanizer is set to be 0.5 MPaG to 2.0 MPaG, and the temperature of a tower kettle is not higher than 90 DEG C; and the deethanizer adopts an open heat pump technology, a certain stage of a product gas compressor is arranged at the top of the deethanizer, a gas phase at the top of the deethanizer is compressed and then enters a condenser to be cooled, a cooled liquid phase is deethanizer reflux liquid, and non-condensable gas is a high-concentration ethylene gas product. Due to the fact that operation is carried out at the intercooling temperature, the energy consumption and investment ofthe process are lower than those of a cryogenic separation process. Due to the fact that a rectification method is adopted for separation, the impurity content of the high-concentration ethylene gas produced through the process is lower than that of an absorption-desorption method, the requirement for downstream production of high-quality ethylbenzene is met, and particularly the requirement for preparing ethylbenzene through a high-concentration ethylene gas-liquid phase method is met.

Description

technical field [0001] The invention belongs to the technical field of catalytic cracking product gas separation, and relates to an intercooling separation device and process for catalytic cracking product gas, which can separate the product gas into high-concentration ethylene gas and other by-products for intercooling separation. Background technique [0002] A refinery equipped with a catalytic cracking unit can convert refinery light hydrocarbons and naphtha into high value-added products such as ethylene, propylene, low-carbon olefins (C4C5), and aromatics. The composition of the product gas varies depending on the cracking method selected by the refinery. Compared with the conventional ethylene plant, the product gas of some cracking units has a low proportion of ethylene, a high proportion of propylene, and more oxygen (it is compared with nitrogen Oxides and organic substances can generate nitro resins below -80°C, and there is a risk of blockage and explosion). At ...

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Problems solved by technology

Since the product gas has undergone a compression-throttling process during the production process, the high-concentration ethylene gas outlet pressure of this patent is 5-15 bar. If the downstream configuration is similar to the liquid-phase ethylbenzene device provided in CN107827692A, it needs to be re-pressurized , there is an energy loss

[0008] To sum up, the production of polymer grade ethylene by cryogenic separation process of conventional ethylene plant is not the most reasonable configuration for each refinery and various cracking conversion units, and the above-mentioned methods for producing high-concentration ethylene gas have their own shortcomings

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