First-stage selective hydrogenation catalyst for cracking gasoline, and preparation method thereof

Abstract

The present invention relates to a first-stage selective hydrogenation catalyst for cracking gasoline, wherein the catalyst comprises an alumina carrier having a macroporous structure and a metal active component palladium supported on the carrier, and the palladium content is 0.2-0.35 wt% based on the total weight of the catalyst. The catalyst of the present invention has advantages of good glue capacity, strong arsenic resistance, strong sulfur resistance, and strong coking inhibition.

Description

technical field

[0001] The invention relates to a selective hydrogenation catalyst for petroleum hydrocarbon products and a preparation method thereof, in particular to a one-stage selective hydrogenation catalyst for pyrolysis gasoline and a preparation method thereof. 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 a...

Examples

Embodiment 1

[0038] First, 8.0 g of the water-soluble chitosan pore-enlarging agent was added to deionized water at 50° C., and then acetic acid was added dropwise until the chitosan was completely dissolved to obtain an acid solution containing the pore-enlarging agent. Weigh 1.46g of phosphoric acid and 7.35g of magnesium nitrate respectively, and completely dissolve phosphoric acid and magnesium nitrate in 70g of distilled water to form an aqueous solution containing phosphorus and magnesium. Weigh 350g of pseudo-boehmite powder and 20.0g of fennel powder into the kneader, mix well, then add the mixed solution of phosphoric acid and magnesium nitrate, and finally add the acid solution containing chitosan to the pseudo-boehmite Knead evenly in the stone, and shape it into a clover shape through kneading-extrusion. Dry at 120° C. for 8 hours, and calcined at 700° C. for 4 hours to obtain an alumina carrier 1 containing phosphorus and magnesium. In carrier 1, phosphorus pentoxide is 0.5wt...

Embodiment 2

[0041] Add 8.0 g of the water-soluble chitosan pore-enlarging agent into deionized water at 50° C., and then add acetic acid dropwise until the chitosan is completely dissolved to obtain an acid solution containing the pore-enlarging agent. Weigh 1.09g of phosphoric acid and 9.12g of magnesium nitrate respectively, completely dissolve phosphoric acid and magnesium nitrate in 70g of distilled water to form an aqueous solution containing phosphorus and magnesium. Weigh 350g of pseudo-boehmite powder and 20.0g of fennel powder into the kneader, mix well, then add the mixed solution of phosphoric acid and magnesium nitrate, and finally add the acid solution containing chitosan to the pseudo-boehmite Knead evenly in the stone, and shape it into a clover shape through kneading-extrusion. Dry at 120° C. for 8 hours, and calcined at 700° C. for 4 hours to obtain an alumina carrier 1 containing phosphorus and magnesium. Then use phosphorus and magnesium to modify the surface of the ca...

Embodiment 3

[0044] The preparation method of the carrier was carried out according to Example 1. The difference is that the auxiliary component in the carrier also contains cerium, and the water-soluble chitosan pore-enlarging agent is replaced with a non-water-soluble chitosan pore-enlarging agent, and the chitosan formic acid solution is stirred with a magnetic stirrer for 30 minutes to obtain Alumina support with macroporous structure3. The contents of the auxiliary components phosphorus, magnesium and cerium in the carrier are respectively 1.8wt%, 2.0wt%, and 0.6wt% of the weight of the carrier. Its specific surface area and pore size distribution are shown in Table 1.

[0045] A palladium solution was prepared to impregnate the alumina carrier 3, dried at 120° C. for 6 hours, and calcined at 500° C. for 5 hours to obtain the catalyst 3 . Catalyst 3 had a palladium content of 0.29 wt%.

technical field

[0001] The invention relates to a selective hydrogenation catalyst for petroleum hydrocarbon products and a preparation method thereof, in particular to a one-stage selective hydrogenation catalyst for pyrolysis gasoline and a preparation method thereof. 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 a...

Examples

Embodiment 1

[0038] First, 8.0 g of the water-soluble chitosan pore-enlarging agent was added to deionized water at 50° C., and then acetic acid was added dropwise until the chitosan was completely dissolved to obtain an acid solution containing the pore-enlarging agent. Weigh 1.46g of phosphoric acid and 7.35g of magnesium nitrate respectively, and completely dissolve phosphoric acid and magnesium nitrate in 70g of distilled water to form an aqueous solution containing phosphorus and magnesium. Weigh 350g of pseudo-boehmite powder and 20.0g of fennel powder into the kneader, mix well, then add the mixed solution of phosphoric acid and magnesium nitrate, and finally add the acid solution containing chitosan to the pseudo-boehmite Knead evenly in the stone, and shape it into a clover shape through kneading-extrusion. Dry at 120° C. for 8 hours, and calcined at 700° C. for 4 hours to obtain an alumina carrier 1 containing phosphorus and magnesium. In carrier 1, phosphorus pentoxide is 0.5wt...

Embodiment 2

[0041] Add 8.0 g of the water-soluble chitosan pore-enlarging agent into deionized water at 50° C., and then add acetic acid dropwise until the chitosan is completely dissolved to obtain an acid solution containing the pore-enlarging agent. Weigh 1.09g of phosphoric acid and 9.12g of magnesium nitrate respectively, completely dissolve phosphoric acid and magnesium nitrate in 70g of distilled water to form an aqueous solution containing phosphorus and magnesium. Weigh 350g of pseudo-boehmite powder and 20.0g of fennel powder into the kneader, mix well, then add the mixed solution of phosphoric acid and magnesium nitrate, and finally add the acid solution containing chitosan to the pseudo-boehmite Knead evenly in the stone, and shape it into a clover shape through kneading-extrusion. Dry at 120° C. for 8 hours, and calcined at 700° C. for 4 hours to obtain an alumina carrier 1 containing phosphorus and magnesium. Then use phosphorus and magnesium to modify the surface of the ca...

Embodiment 3

[0044] The preparation method of the carrier was carried out according to Example 1. The difference is that the auxiliary component in the carrier also contains cerium, and the water-soluble chitosan pore-enlarging agent is replaced with a non-water-soluble chitosan pore-enlarging agent, and the chitosan formic acid solution is stirred with a magnetic stirrer for 30 minutes to obtain Alumina support with macroporous structure3. The contents of the auxiliary components phosphorus, magnesium and cerium in the carrier are respectively 1.8wt%, 2.0wt%, and 0.6wt% of the weight of the carrier. Its specific surface area and pore size distribution are shown in Table 1.

[0045] A palladium solution was prepared to impregnate the alumina carrier 3, dried at 120° C. for 6 hours, and calcined at 500° C. for 5 hours to obtain the catalyst 3 . Catalyst 3 had a palladium content of 0.29 wt%.

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