A method for selective hydrogenation of cracked C6-C8 cuts

Abstract

The invention relates to a method for carrying out selective hydrogenation on pyrolytic C6-C8 fractions. A catalyst comprises an alumina carrier having a macroporous structure, and a metal active component-palladium loaded on the carrier, wherein the content of the palladium is 0.2-0.35wt% of the total weight of the catalyst, the alumina carrier having the macroporous structure contains auxiliary components-phosphorus and magnesium, and the contents of the auxiliary components-phosphorus (P2O5) and magnesium (MgO) respectively account for 0.1-2.5wt% and 0.1-2.5wt% of the mass of the carrier; the hydrogenation process conditions are as follows: the reaction inlet temperature is lower than or equal to 45 DEG C, the reaction pressure is 2.5-4.5MPa, the volume ratio of hydrogen to oil is 60-450, and the liquid volume space velocity is 3.0-5.5h<-1>. The catalyst is high in adaptability for pyrolysis gasoline raw materials having different arsenic contents and sulphur contents, and is good in low-temperature activity.

Description

technical field [0001] The invention relates to a selective hydrogenation method for petroleum hydrocarbon products, especially suitable for one-stage selective hydrogenation of pyrolysis gasoline, and is a method for selective hydrogenation of cracked C6-C8 fractions. Background technique [0002] Pyrolysis gasoline is an important by-product of steam cracking industrial production of ethylene and propylene, including C5-C10 fractions. The composition of pyrolysis gasoline is very complex, mainly including benzene, toluene, xylene, mono-olefins, di-olefins, straight-chain alkanes, cycloalkanes, and organic compounds of nitrogen, sulfur, oxygen, chlorine and heavy metals, etc., a total of more than 200 components, of which Benzene, toluene, and xylene (collectively referred to as BTX) are about 50-90%, and unsaturated hydrocarbons are 25-30%. According to the characteristics of a large amount of aromatics in pyrolysis gasoline, it has a wide range of uses. It can be used as...

AI Technical Summary

Problems solved by technology

The disadvantage is that the size of the macropore (300nm or 400nm) is completely determined by the size of the polystyrene droplet introduced twice, that is, the size of the macropore depends on the size of the polystyrene droplet

The pore size cannot be adjusted by partially changing the components of the solution itself and the interaction of organic molecules in the system

Huining Li et al. (Inorganic Chemistry, 2009, 48:4421) also used the sol-gel method to introduce polymethyl methacrylate (PMMA) droplets with a single dispersed phase into the mixed solution using F127 as a template to achieve large Pore-the formation of macropores in mesoporous alumina, the disadvantage is that the size of the macropores is completely determined by the size of the secondary introduction of polymethyl methacrylate droplets, which cannot be achieved by partially changing the components of the solution system itself The adjustment of the pore size is used to realize the formation of the macropore-mesopore composite pore structure, so it is impossible to realize the controllable adjustment of the macropore-mesopore diameter. In the process of use, especially for the macromolecular catalytic process of complex components limitations

The invention has the disadvantage of low diene hydrogenation selectivity, and provides a new catalyst for one-stage selective hydrogenation of pyrolysis gasoline

Images