C2 fraction selective hydrogenation method

Abstract

The invention relates to a C2 fraction selective hydrogenation method. A fixed bed reactor used for hydrogenation is positioned behind a demethanation tower, allows a C2 material from a front deethanization tower in an ethylene device to undergo pressurization hydrogen matching, enter a heat insulation bed reactor and undergo selective hydrogenation; the fixed bed reactor is filled with a Pd-Pb series catalyst, and hydroxydipyridine combined to a carrier and an active component form a metal complex through the combination of an alumina series carrier and a hydroxy group-containing dipyridine derivative in the preparation method of the catalyst. The hydrogenation reaction activity of the method provided by the invention is greatly better than that of traditional hydrogenation methods, and the generation amount of green in the hydrogenation process is greatly reduced. Reduction of the green oil makes the active site of the catalyst not be covered with byproducts and the activity and the selectivity of the catalyst be well kept; and when a hydrogenation raw materials contains 1000ppm or below of a C4 fraction, the catalyst also has an excellent hydrogenation performance.

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

[0024] The hydrogenation raw material of the C2 hydrogenation unit also contains a certain amount of C4 fraction and propyne and propadiene (MAPD). Causes the loss of palladium, which affects the activity of the catalyst. In severe cases, it can cause catalyst deactivation, which brings the risk of alkyne leakage in the device

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