Hydrocarbon steam cracking sequential separation process and propane dehydrogenation process coupling method

Abstract

The invention discloses a method for coupling a hydrocarbon steam cracking sequential separation process and a propane dehydrogenation process in the technical field of petrochemical engineering, andaims at the characteristics of cracking gas of a hydrocarbon steam cracking device and reaction gas of a propane dehydrogenation device, By coupling the two processes, the purposes of reducing equipment investment, reducing device energy consumption, reducing construction land and prolonging the service life of the alkyne hydrogenation catalyst are achieved, and long-period stable production of the coupling device is facilitated.

Description

technical field [0001] The invention belongs to the field of petrochemical industry, and in particular relates to a method for coupling a sequential separation process of hydrocarbon steam cracking and a propane dehydrogenation process. Background technique [0002] Ethylene is one of the most important basic raw materials in the petrochemical industry, and its output is a symbol to measure the overall development level of a country's petrochemical industry. Ethylene production technologies include hydrocarbon steam cracking, methanol to olefins, and olefin conversion, among which hydrocarbon steam cracking is dominant. At present, the patent holders of hydrocarbon steam cracking technology in the world mainly include KBR Company of the United States, Linde Company of Germany, Lummus Company of the United States and Technip Company of France. These technologies all adopt the cryogenic separation process to obtain ethylene products. For different cracking raw materials, the...

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Problems solved by technology

They directly mix the cracked gas and the reaction gas, compress, wash with alkali, dry, and then send to the sequential separation system for cryogenic separation, without considering the characteristics of high hydrogen in the propane dehydrogenation reaction gas, which will lead to hydrogen / methane separation Increased cooling load at -101°C and below required for methane / ethylene separation

[0006] Chinese patent CN110914225A discloses a process and equipment for the combination of propane dehydrogenation and steam cracking to produce propylene. This patent recycles propane back to the steam cracking process instead of propane dehydrogenation. Although the ethylene yield is increased, the methane content is also increased. , leading to an increase in subsequent separation energy consumption and a decrease in propylene yield

At the same time, this patent does not consider that the reaction gas contains a small amount of carbon dioxide. If it is not removed by alkali washing, there is a risk of blocking the cold box.

[0007] However, none of the above-mentioned published patents has optimized the application of the deoiling tower of the propane dehydrogenation unit. The deoiling tower can share the depropanization tower of the hydrocarbon steam cracking unit to remove heavy components to achieve further coupling

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