A kind of nickel-based hydrogenation catalyst and preparation method thereof

Abstract

The invention provides a nickel-based hydrogenation catalyst and a preparation method thereof. The nickel-containing alumina carrier is impregnated with a nickel-containing solution, dried and roasted to obtain a catalyst; the nickel-containing alumina carrier is formed from nickel-containing pseudo-boehmite. It is obtained by roasting; the preparation process of nickel-containing pseudo-boehmite includes acid-base neutralization and gel-forming processes. The invention organically combines nickel and pseudo-boehmite, so that the active component nickel is effectively dispersed in the pseudo-boehmite and forms a specific crystal form of nickel-containing alumina carrier. At the same time, the pore structure and acidity of the carrier are improved. It has better regulating effect. The finally prepared catalyst has high hydrogenation activity and selectivity, and good chemical stability and thermal stability.

Description

technical field [0001] The invention relates to a nickel-based hydrogenation catalyst and a preparation method thereof, in particular to a nickel-based hydrogenation catalyst with nickel-containing alumina as a carrier and a preparation method thereof. Background technique [0002] Ethylene is one of the most produced chemical products in the world and is the core of the petrochemical industry. The composition of ethylene cracking fraction is complex and changeable, and the demand for hydrogenation catalyst is also increasing. The pyrolysis products contain highly unsaturated hydrocarbons, such as alkynes, diolefins, phenylacetylene, etc., which must be selectively hydrogenated to make them into corresponding monoolefins. With the continuous increase of my country's ethylene production capacity, the variability of domestic cracking raw materials, cracking equipment and cracking methods make some manufacturers deteriorate cracking raw materials, increase hydrogenation load, ...

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Problems solved by technology

[0004] CN1218822A has reported a kind of Ni / Al 2 o 3 A selective hydrogenation catalyst suitable for pyrolysis gasoline fractions. The catalyst is prepared by loading nickel on an alumina carrier containing lithium or alkaline earth metals. This catalyst is not good in hydrogenation load and hydrogenation stability.

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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