A method for selective hydrogenation of carbon distillates in a sequential separation process

Abstract

The invention relates to a selective hydrogenation method for a C2 fraction in a sequential separation process. A fixed bed reactor for hydrogenation is arranged after a demethanizing column. A C2 material from a front deethanizing column in an ethylene plant is subjected to pressurization and hydrogen addition and then is fed into an adiabatic bed reactor to perform the selective hydrogenation. The fixed bed reactor is filled with a Pd-Au-series catalyst, which is prepared by combining an alumina carrier and a bipyridine derivative having a hydroxyl group, wherein a metal complex is formed from the hydroxyl bipyridine combined on the carrier and active components. Through the method, activity and selectivity of the hydrogenation reaction are greatly improved than that in a conventional hydrogenation method. The method greatly increases the yield of ethylene and greatly reduces the generation of green oil, so that active centers of the catalyst are not covered by side products and the catalyst maintains the activity and selectivity well.

Description

technical field [0001] The invention relates to a selective hydrogenation method, in particular to a carbon-two selective hydrogenation method in a sequential separation process. 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, the selectivity of the catalyst is excellent, which can make ethylene generate as little ethane as possible, which is beneficial to improving the entire process. It is of great significance to improve the ethylene yield of the process and improve the economic benefits of the device. [0003] The cracked carbon distillate contains acetylene ...

AI Technical Summary

Problems solved by technology

Using this patented method, the carrier adsorbs a specific polymer compound through the chemical adsorption of the hydroxyl group of alumina and the polymer, and the amount of the polymer compound adsorbed by the carrier will be limited by the number of hydroxyl groups of alumina; the functionalized polymer and Pd The complexation effect is not strong, and sometimes the loading capacity of the active components does not meet the requirements, and some active components remain in the impregnation solution, resulting in an increase in the cost of the catalyst; the preparation of carbon dioxide hydrogenation catalysts by this method also has the disadvantage of complicated process flow

Images