C2 fraction selective hydrogenation method

Abstract

The invention relates to a C2 fraction selective hydrogenation method. The C2 fraction selective hydrogenation method comprises the following steps of feeding an effluent which is in an ethylene device and is discharged from the top of a demethanizer into an adiabatic bed reactor, and carrying out selective hydrogenation to remove ethyne. The C2 fraction selective hydrogenation method is characterized in that selective hydrogenation catalyst carriers comprise alumina or mainly comprising alumina, have a double-humped hole distributed structures and contain double active components of Pd and Ni. In catalyst preparation, a coking-resistant component Ni in the form of microemulsion enters into large holes of the carriers so that the coking-resistant component Ni is mainly distributed in the large holes of the carriers and thus a catalyst surface coking degree is greatly reduced, the compound subjected to hydrogenation saturation is gradually diffused into catalyst channels, channel blocking is avoided, a catalyst service life is greatly prolonged, a green oil yield and catalyst coking are obviously reduced and device operation economic benefits are improved.

Description

technical field [0001] The invention relates to a method for selective hydrogenation, in particular to a method for selective hydrogenation of carbon distillates to remove acetylene. Background technique [0002] The production of polymer grade ethylene is the leader of the petrochemical industry, and polymer grade ethylene and propylene are the most basic raw materials for downstream polymerization units. Among them, the selective hydrogenation of acetylene has an extremely important impact on the ethylene processing industry. In addition to ensuring that the acetylene content at the outlet of the hydrogenation reactor reaches the standard, it is also necessary to ensure that the catalyst has excellent selectivity, so that ethylene can generate as little ethane as possible, and improve the overall efficiency. The ethylene yield of the process. In addition, the high anti-coking performance of the catalyst can prolong the service life of the catalyst, which is of great signi...

AI Technical Summary

Problems solved by technology

[0021] However, in the carbon two hydrogenation reaction, the generation of green oil and the coking of the catalyst are important factors affecting the reaction life of the catalyst. The activity, selectivity and service life of the catalyst constitute the overall performance of the catalyst. The above methods may be useful for improving catalyst activity, Selectivity proposes a better method, but it does not solve the problem that the catalyst is easy to coke, or it solves the problem that the catalyst is easy to generate green oil and coke, but it does not solve the problem of selectivity

Although the carrier with a macroporous structure can improve the selectivity, the larger molecules generated by the polymerization and chain growth reactions tend to accumulate in the macropores of the carrier, causing coking and deactivation of the catalyst and affecting the service life of the catalyst.

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