CN1071443A

CN1071443A - A kind of catalyzer that is used for one-stage selective hydrogenation of gasoline splitting

Info

Publication number: CN1071443A
Application number: CN 91109503
Authority: CN
Inventors: 刘佩环; 刘瑞成; 柴香暖
Original assignee: CHEMICAL INST LANZHOU CHEMICAL
Current assignee: China Petrochemical Corp
Priority date: 1991-10-04
Filing date: 1991-10-04
Publication date: 1993-04-28
Anticipated expiration: 2006-10-04
Also published as: CN1026494C

Abstract

A kind of catalyzer that is used for one-stage selective hydrogenation of gasoline splitting is to be made of δ, α mixing crystal formation aluminum oxide and the metallic palladium that supports on it.Carrier bulk density 0.75～0.85 grams per milliliter, specific pore volume 〉=0.45 milliliter/gram, 100～120 meters of specific surfaces ²/ gram, Na ₂O content≤0.07% (weight), crushing strength is 8～10kgf/ grain radially, axially～the 50kgf/ grain.The palladium content that with the carrier is benchmark is 0.28～0.30% (weight), is lamella catalyst.Compare with existing catalyzer, its hydrogenation activity is moderate, and reaction temperature rising is low, and diolefin hydrogenation selectivity height is so help prolonging the regeneration period of catalyzer.When arsenic content when 50ppb rises to 853ppb, show the ability of stronger anti-arseniasis.

Description

A kind of catalyzer that is used for one-stage selective hydrogenation of gasoline splitting

The present invention relates to a kind of one-stage selective hydrogenation of gasoline splitting catalyzer.

Pyrolysis gasoline is the important by-product that ethylene industry is produced, and is C ₅～C ₉Fraction, according to the difference of cracking stock and cracking severity, its output accounts for more than 50% of ethylene production capacity, and wherein aromaticity content accounts for 40～80%, is the important source of aromatic hydrocarbons therefore.Main cutting C on the industrial production ₆～C ₈Fraction, through one-stage selective hydrogenation, remove the height unsaturated hydrocarbons, as chain conjugated dienes, vinylbenzene, cyclic conjugated diene etc., again through the secondary hydrogenation desulfurization, make the extractive raw material of aromatic hydrocarbons behind the organic compound of removal monoolefine and sulphur, nitrogen, oxygen, produce the usefulness of benzene,toluene,xylene, also can be only through one-stage hydrogenation, remove diolefin, keep most of monoolefine, thereby obtain stable motor spirit dopant, or the higher motor spirit of octane value.The pyrolysis gasoline hydrogenation catalyst of using on the Chemical Manufacture has Pd-Cr/Al at present ₂O ₃Deng bimetallic catalyst, Pd/Al is arranged also ₂O ₃Catalyzer.Existing P d-Cr/Al ₂O ₃The hydrogenation activity of bimetallic catalyst, many indexs such as diolefin hydrogenation selectivity are all not as existing P d/Al ₂O ₃Catalyzer.Diolefin in the pyrolysis gasoline is polymerization at high temperature or dehydrogenative condensation easily, therefore one section catalyst hydrogenation activity is unsuitable too high, be advisable with moderate, and has a higher diolefin hydrogenation selectivity, temperature rise increases because monoolefin hydrogenation induces reaction to reduce, and then quickens carbonaceous and the deposition of burnt matter on catalyzer, and catalyzer should have bigger appearance glue ability simultaneously, to prolong the regeneration period of catalyzer, the existing just Pd/Al of above-mentioned condition ₂O ₃Catalyzer is failed the problem of fine solution.In addition, the existence of micro amount of arsenic in the pyrolysis gasoline is to cause Pd/Al ₂O ₃How the important factor of poisoning of catalyst improves Pd/Al ₂O ₃The anti-arseniasis ability of catalyzer, promptly arsenic can not be adsorbed on the catalyst surface securely when arsenic content surpasses 50ppb, in case arsenic content returns to normally, the arsenic of absorption just can be washed out by qualified stock oil, catalyzer promptly recovers its hydrogenation performance fully, and this is very important in industrial application.

It is moderate to the purpose of this invention is to provide a kind of hydrogenation activity, diolefin hydrogenation selectivity height, and reaction temperature rising is low, has stronger anti-poisoning capability and operational condition pyrolysis gasoline hydrogenation catalyst stably.

Catalyzer of the present invention supports precious metal palladium (Pd) by δ, α mixing crystal formation aluminum oxide and constitutes.Palladium is eggshell type at carrier surface and distributes, and the content that with the carrier is benchmark is that 0.28～0.30%(is heavy), 0.09～0.15 millimeter of shell thickness.δ, α mixing crystal formation alumina supporter bulk density 0.75～0.85 grams per milliliter, specific pore volume 〉=0.45 milliliter/gram, 100～120 meters of specific surfaces ²/ gram, N _A2O content≤0.07%(is heavy), horizontal crushing strength 8～10Kgf/ grain, vertically crushing strength is the mechanical wafers about the 50Kgf/ grain.Catalyzer of the present invention is applicable to that the diene value reaches 37 gram iodine/100 gram oil, and iodine number reaches the hydrogenation reaction of the pyrolysis gasoline of 148 gram iodine/100 gram oil.

Preparation of catalysts method of the present invention is identical with common lamella catalyst dipping technique: earlier with a kind of liquid preimpregnation carrier that can dissolve each other with steeping fluid, again with containing δ, α the mixings crystal formation alumina supporter of the salt solution impregnation of precious metal palladium through preimpregnation, soaked carrier is through washing, drying, roasting promptly gets the oxidation catalyst finished product in air.Finished catalyst only needs to lead to hydrogen reducing and can use in reactor.

Catalyzer of the present invention and the one section Pd/Al of pyrolysis gasoline that uses at present ₂O ₃Catalyzer is compared has following advantage:

Therefore 1. hydrogenation activity is moderate, and the diolefin hydrogenation selectivity is higher, has reduced the thermal discharge in the reaction process relatively, and the corresponding reduction of reaction temperature rising makes smooth operation, has avoided causing because of catalyst activity is too high reaction uppity situation (data see Table 1).

2. anti-arseniasis ability is strong (seeing example 4).

3. catalyst bulk density of the present invention is lower, when being applied to 300,000 tons of/year supporting pyrolysis gasoline of ethylene unit unit one-stage hydrogenation reactors, and its charge weitght and existing Pd/Al ₂O ₃Catalyzer is compared and can be reduced 29%, still can reach identical material treatment capacity.

4. catalyzer of the present invention is preserved with oxidation state, has therefore reduced the difficulty in the keeping, existing Pd/Al ₂O ₃Catalyzer is sold to go back ortho states.Catalyzer of the present invention logical on the spot hydrogen reducing in reactor can use.

Example 1

With deionized water preimpregnation carrier, filter solid carbon dioxide part then, use the palladium chloride solution impregnated carrier, again through washing, dry, in air, make catalyzer of the present invention, its physicals such as table 2 after the roasting.

Example 2

Carry out 150 hours activity ratings with example 1 described A, B, C on 300 milliliters of adiabatic reaction apparatus, evaluation result sees Table 3.

* restrain iodine/100 gram oil

Example 3

C catalyzer with example 1 carries out estimating in 1000 hours on 300ml adiabatic reactor reaction unit, and synthesis result sees Table 1.

Example 4

C catalyzer with example 1 carries out stability test in 1000 hours on 100ml isothermal trickle bed, synthesis result sees Table 4.

* restrain iodine/100 gram oil

Example 5

It is on probation to carry out industry with the C catalyzer of example 1 in tonnage level ethylene unit pyrolysis gasoline unit first stage reactor, and its loadings is that prior art is used Pd/Al ₂O ₃71% of catalyzer.Through running in 4000 hours, the charging diene is 18～28 gram iodine/100 gram oil, iodine number 65～86 gram sulphurs/100 gram oil, 16～25 ℃ of bed thermal insulation warmings, product diene value 1.7～2.5 gram iodine/100 gram oil, the diolefin hydrogenation rate is calculated as 86.5～93.3% by fresh feed oil, when iodine content when the 50ppb of design load increases to 853ppb, product diene value increases to 7.1 gram iodine/100 gram oil, and iodine content is reduced to just often, and product diene value can return to 2.23 gram iodine/100 gram oil.

Claims

1, a kind of catalyzer that is used for one-stage selective hydrogenation of gasoline splitting is characterized in that it is supported precious metal palladium and constituted by δ, α mixing crystal formation aluminum oxide.

2, by the described hydrogenation catalyst of claim 1, it is characterized in that said carrier bulk density 0.75～0.85 grams per milliliter, specific pore volume 〉=0.45 grams per milliliter, 100～120 meters of specific surfaces ²/ gram, N _A2O content≤0.07%(weight), the horizontal 8～10Kgf/ grain of crushing strength, vertically the 50Kgf/ grain is mechanical compression molding.

3,, it is characterized in that with the carrier being that the content of precious metal palladium of benchmark is 0.28～0.30%(weight by the described hydrogenation catalyst of claim 1), be eggshell type at carrier surface and distribute 0.09～0.15 millimeter of finished catalyst shell thickness.

4, by the described hydrogenation catalyst of claim 1, it is characterized in that this catalyzer is applicable to that the diene value reaches 37 gram iodine/100 gram oil, iodine number reaches the one-stage selective hydrogenation of the pyrolysis gasoline of 148 gram iodine/100 gram oil.