Selective hydrogenation method of alkyne and dialkene in alkene stream

Abstract

The invention provides a selective hydrogenation method of alkyne and dialkene in an alkene stream. The method comprises the steps that: an alkene stream containing alkyne and / or dialkene, and hydrogen are delivered into a hydrogenation reactor provided with a supported palladium catalyst; alkyne and / or dialkene in the alkene stream are hydrogenated into alkene under conditions of: a temperature in of 10 to 80 DEG C, a molar ratio of hydrogen to a total amount of alkyne and dialkene of 1 to 10, and a reaction pressure of 0.1 to 4 Mpa, such that alkyne and / or dialkene in the alkene stream are removed. The supported palladium catalyst comprises a carrier, palladium and optional modifying components. With a carbon monoxide adsorption in situ infrared spectroscopy method, the catalyst is tested under a temperature of 40 DEG C. In an obtained infrared spectrogram, an area ratio of an overhead absorption peak at a location of 1983 to 1990cm-1 to that at the location of 1870 to 1930cm-1 is lower than 0.2, and preferably 0.15. The method provides a high selectivity in the selective hydrogenation of alkyne and dialkene. The method can operate for a long period.

Description

technical field [0001] The present invention relates to a process for selective hydrogenation, and more particularly, the present invention relates to a process for the selective hydrogenation of alkynes and dienes in olefin streams. Background technique [0002] Products such as ethylene, propylene, and butene produced during steam cracking, catalytic cracking, or thermal cracking contain a small amount of alkyne or diene, and these impurities are harmful to subsequent polymerization and other reactions. Their presence not only deteriorates polymer properties, but can also cause explosion hazards. The selective catalytic hydrogenation method is usually used to remove the concentration of alkynes and dienes to a very low level (mole fraction<1×10 -6 ) to obtain polymer-grade products; meanwhile, it can also increase the yield of monoolefins and improve resource utilization. In the C4 fraction, according to the difference of the raw material and the demand for the produc...

AI Technical Summary

Problems solved by technology

Due to the need to include specific Pd precursors or crystal form control agents in the preparation process, the composition of the catalyst becomes complicated and the preparation process is more cumbersome

In addition, the adsorption capacity of the reactants on the surface of the catalyst noble metal is an important factor affecting its activity and selectivity, which has not been reflected in the existing literature.

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