A method and device for the separation of hydrocarbon cracking gas and the production of ethylbenzene

Abstract

The invention provides a hydrocarbon cracking gas separation and a method and device for producing ethylbenzene, which are applied in the technical field of separation and utilization of hydrocarbon cracking devices. Process: After pre-cooling and separation, the products processed in the upstream enter the demethanizer and the pre-demethanizer respectively. The gas phase at the top of the demethanizer is recovered as ethylene-containing dry gas, which enters the downstream gas-phase legal ethylbenzene reactor, and the bottom of the demethanizer Both the production and the bottom production of the pre-demethanizer enter the deethanizer, and the liquid phase ethylene ethane gas is produced from the top of the deethanizer, and the ethylene ethane gas enters the downstream liquid phase ethylbenzene reactor. The outlet materials of the two types of reactors pass through the ethylbenzene separation unit to obtain high-purity ethylbenzene products. Compared with the conventional ethylene cryogenic separation process combined with the pure ethylene liquid-phase ethylbenzene process device, the present invention has the advantages of lower investment cost, relatively simple process, low comprehensive energy consumption of the device group, and strong anti-interference ability.

Description

technical field [0001] The invention belongs to the technical field of separation and utilization of cracked gas products of a hydrocarbon cracking device, and relates to a method and a device for obtaining ethylene-containing dry gas and ethylene-ethane mixed gas through fuzzy separation of cracked gas, and further preparing high-purity ethylbenzene. Background technique [0002] Ethylene is one of the most produced chemicals in the world, an important product in the petrochemical industry, and a basic chemical raw material for the production of the three major synthetic materials. Ethylene can react with benzene to produce ethylbenzene. Ethylbenzene is an important chemical raw material. The production processes mainly include gas-phase method and liquid-phase method. The former is currently mostly used to process catalytic cracking dry gas, while the latter has higher requirements on the purity of ethylene. Ethylene is usually produced by thermal cracking or catalytic cra...

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Problems solved by technology

This patent adopts the pre-deethanization and intermediate cold separation process, which can obtain higher concentration of ethylene gas. The lowest temperature in the system is -38°C. There is no need to add ethylene compressors and cold boxes, and the equipment investment cost is relatively low. However, the ethylene gas produced by this process When high-concentration ethylene gas produces ethylbenzene, the xylene content is slightly higher, and the ethylene produced by catalytic cracking all enters the ethylene-rich dry gas. The ethylene concentration in the ethylene-rich dry gas depends on the composition of the cracked gas, and the anti-fluctuation ability of the device is poor

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