Selective hydrogenation catalyst and preparation method thereof

Abstract

The invention discloses a selective hydrogenation catalyst and a preparation method thereof. In the catalyst, aluminum oxide containing titanium and silicon is taken as a carrier, an active metal ingredient is palladium, an aid ingredient is Mo and / or Co, and the active metal ingredient and the aid ingredient are distributed on the surface of the carrier in an eggshell shape; the aluminum oxide containing the titanium and the silicon is prepared from sodium aluminate, sodium silicate, titanium sulfate and CO2 by a precipitation method; the sodium aluminate and the sodium silicate are subjected to cocurrent flow, the CO2 is introduced to make the pH value constant for precipitation, the titanium sulfate and a NaHCO3 and / or Na2CO3 solution are subjected to cocurrent flow precipitation, and the obtained aluminum oxide containing the titanium and the silicon has large pore volume and specific surface area and high high-temperature stability; in addition, the aid ingredient can interact with the active ingredient palladium, palladium particles are uniformly distributed, and interaction between the palladium and the carrier can be enhanced, so that the loss of the palladium is reduced, the utilization rate of the palladium is improved, and the service life of the catalyst is prolonged.

Description

technical field [0001] The invention relates to a selective hydrogenation catalyst and a preparation method thereof. The catalyst is suitable for selective hydrogenation of middle and low distillate oils, especially for pyrolysis gasoline C 9 One-stage selective hydrogenation process of distillate. Background technique [0002] Using light hydrocarbons, naphtha, diesel oil or heavy oil as raw materials, in the process of producing ethylene by high temperature cracking in the presence of water vapor, liquid by-products containing more than five hydrocarbons are produced, and the liquid with a dry point of 205°C is obtained by fractional distillation. For pyrolysis gasoline. pyrolysis gasoline C 9 Distillate, which is separated from pyrolysis gasoline by extraction and C 5 Fraction, C 6 ~C 8 The remaining fraction after fractionation accounts for about 10% to 20% of the total ethylene production. [0003] With the rapid development of the petrochemical industry, especial...

AI Technical Summary

Problems solved by technology

CN85100761A discloses a fiber-supported catalyst for selective hydrogenation of diolefins in pyrolysis gasoline fractions, with a specific surface area of ​​20-200m 2 / g, η-Al with a pore volume of 0.1-0.3ml / g 2 o 3 Porous fibrous carrier, the initial activity of the catalyst is high, but the pore volume is too small. When the colloid in the raw material of the pyrolysis gasoline hydrogenation unit exceeds the standard, the upper pores of the catalyst are easy to coke and block, which affects the hydrogenation stability of the catalyst

This catalyst is more suitable for the whole fraction of pyrolysis gasoline, but for the heavier fraction, due to the relatively low specific surface area and pore volume, it affects the activity and selectivity of the catalyst, and the catalyst deactivates quickly, the stability of the catalyst is poor, and the cycle is short, which increases the Operating costs