Method for removing phenylacetylene through selective hydrogenation under existence of styrene

Abstract

The invention provides a method for removing phenylacetylene through selective hydrogenation under the condition of styrene existence. C8 fractions are preheated and then enter a fixed bed hydrogenation reactor; a lower feeding mode is used; a catalyst is charged in the reactor; the hydrogenation process conditions are shown as follows: the inlet temperature is 10 to 70 DEG C; the air speed is 0.1to 6.0h<-1>; the pressure is between 0.1 MPa and 2.0 MPa; the volume ratio of hydrogen gas and fresh oil is 1 to 100; catalysts use nickel-containing aluminum oxide as carriers; 10 to 20 weight percent of nickel oxide, 0.01 to 10 weight percent of silver oxide, 0 to 8 weight percent of cerium oxide and / or lanthanum oxide, and 0 to 5 weight percent of alkali metal and / or alkaline-earth metal oxides are contained; the specific surface area of the catalyst is 70 to 170 m<2> / g; the hole volume is 0.30 to 0.50ml / g; precursors of nickel-containing aluminum oxide carriers are nickel-containing pseudo-boehmite; the acid-base neutralization and gel forming processes exist in the preparation process of the nickel-containing pseudo-boehmite. By using the method provided by the invention, phenylacetylene is removed to low concentration through hydrogenation; in addition, styrene is not lost until the quantity of the styrene is not increased.

Description

technical field [0001] The method relates to a method for selectively hydrogenating phenylacetylene in the presence of styrene; specifically, it relates to a selective hydrogenation of a nickel-silver catalyst with nickel-containing alumina as a carrier in the presence of styrene Method for removing phenylacetylene. Background technique [0002] Styrene (ST) is an important monomer for the production of polystyrene, ABS resin and styrene-butadiene rubber. It is difficult to meet the market demand for styrene by the technology of dehydrogenation of ethylbenzene alone, and the dehydrogenation of ethylbenzene exists The disadvantage of high production costs. The production of styrene from the by-product C8 fraction of cracking ethylene is becoming an attractive new way to increase the production of styrene. [0003] Pyrolysis gasoline is a by-product of the ethylene industry, and its output is about 60-70% of the ethylene production capacity. The C8 fraction is used to extrac...

AI Technical Summary

Problems solved by technology

Therefore, there are the following problems in the impregnation process: (1) due to the constant water absorption of the carrier, the volume of the impregnating solution using the equal volume impregnation method is constant, and the high addition of active metal components will cause incomplete dissolution; (2) the preparation of the catalyst process It is necessary to impregnate the active component multiple times in the medium, twice, three times or even four times to impregnate a certain amount of active component on the carrier, which causes problems such as complicated preparation process, long preparation cycle, and loss of active component; (3 ) In the process of multiple impregnation, it is often necessary to add organic or inorganic dispersants to the impregnation solution to increase the dispersion of active metal components, but these will have the problem of removal during post-treatment

However, the active metal compound and aluminum hydroxide dry rubber powder or alumina powder are directly mixed and formed by kneading method. This method has problems such as uneven mixing of crystal particles and deterioration of catalyst strength. It is not easy to combine with each other to form a specific skeleton structure

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