CN102294269A

CN102294269A - Hydrodesulfurization catalyst for sulfur-resisting noble metal

Info

Publication number: CN102294269A
Application number: CN2011101763872A
Authority: CN
Inventors: 李翔; 王敬伟; 王安杰; 段维芳
Original assignee: Dalian University of Technology
Current assignee: Dalian University of Technology
Priority date: 2011-06-20
Filing date: 2011-06-20
Publication date: 2011-12-28

Abstract

The invention provides a hydrodesulfurization catalyst for sulfur-resisting noble metal, which belongs to the technical field of petroleum processing and relates to a solid catalyst used in the hydrodesulfurization process of petroleum distillates. The hydrodesulfurization catalyst for the sulfur-resisting noble metal is characterized by comprising the following steps: using a porous silica-based material modified by silanization as a carrier for carrying the salt of the noble metal or the organic coordination compound of the noble metal, drying to obtain an oxidation-state precursor of the catalyst after roasting at 350 to 500 DEG C, then heating up to 200 to 400 DEG C in the atmosphere of hydrogen at the rate of 1 to 10 DEG C/min, reducing for 0 to 5 hours at this temperature and preparing the load type hydrodesulfurization catalyst for the noble metal. The hydrodesulfurization catalyst for the sulfur-resisting noble metal has the effects and advantages that the prepared catalyst for the noble metal has very high catalytic reaction activity to an aromatic heterocyclic sulfur compound in petroleum fractions under a typical industrial application condition; and moreover, the hydrodesulfurization catalyst for the sulfur-resisting noble metal has better sulfur-resisting stability and very low cracking activity and can be used for producing clean fuel oil.

Description

A kind of noble metal hydrogenation of anti-sulphur desulphurization catalyst

Technical field

The invention belongs to the Petroleum Processing Technology field, relate to employed solid catalyst in gasoline, kerosene and the diesel oil fraction oil of petroleum hydrodesulfurization.

Background technology

Can form SO after the sulfur-containing organic compound burning in the fuel oil _x, be one of main source of atmospheric pollution.In recent years, along with the aggravation of crude oil heaviness and inferiorization trend, sulfur-containing organic compound content increases gradually in the fuel oil, but the environmental requirement increasingly stringent, therefore, oil refining industry in various countries' faces at cost and increases the common difficulty that reduces the product oil sulfur content under the little prerequisite.

In oil plant, removing mainly of sulfur-containing organic compound realized by hydrodesulfurization (HDS) technology in the oil product.Traditional HDS catalyst is load type Co-Mo, Ni-Mo or Ni-W bimetallic sulfide, though update through decades, its activity still can't satisfy the requirement of the environmental regulation of increasingly stringent.Reason is a petroleum distillate after the HDS reaction, residual sulfur-containing compound mainly be the dibenzothiophenes (DBT) of aromatic heterocycle and alkyl-substituted derivatives thereof as 4, the 6-dimethyl Dibenzothiophene (4,6-DMDBT).These big molecule aromatic sulfur-containing compounds have bigger space steric effect, and feasible wherein sulphur atom is difficult to the activated centre near sulfide catalyst.After aromatic ring in these sulfur-containing compounds is by hydrogenation, can reduce steric effect, improve the HDS activity of molecule.Therefore good deep hydrodesulfurizationof catalyst generally should have higher hydrogenation activity.

Carried noble metal is the important hydrogenation catalyst of a class, under lower temperature and pressure aromatic hydrocarbons is had very high hydrogenation activity.Studies show that Pd/ γ-Al ₂O ₃, Pt/ γ-Al ₂O ₃And Pt-Pd/ γ-Al ₂O ₃To 4,6-DMDBT shows very high HDS activity, has become important deep hydrodesulfurizationof catalyst (J.Catal., 2006,242 (1): 207-216; J.Catal., 2005,235 (1): 229-240).But the weakness of noble metal catalyst maximum is not anti-sulphur, especially under the deep hydrodesulfurizationof situation, and H ₂The S dividing potential drop is higher, and noble metal catalyst is easily because of the sulfur poisoning rapid deactivation.Therefore under maintenance or the active prerequisite of raising noble metal catalyst HDS, improve its sulfur tolerance and become the restriction noble metal catalyst in one of deep hydrodesulfurizationof field key in application problem.Carrier is the important component part of noble metal heterogeneous catalyst.In general, the acidity that improves carrier help improving the active and sulfur tolerance of noble metal catalyst HDS (Angew.Chem.Int.Ed., 2008,47 (44), 8478-8481).But when improving support acidity, also side reactions such as aggravation cracking easily, coking influence product liquid to receive and catalyst life, have limited the application of acid carrier in Hydrobon catalyst.

Summary of the invention

The purpose of this invention is to provide a kind of carried noble metal Hydrobon catalyst, solved the anti-sulphur problem of noble metal, catalyst has kept lower cracking activity simultaneously.

Technical scheme of the present invention is to make carrier with the silica of silanization modification, silica-rich zeolite, MCM-41 or SBA-15 silicon-based mesoporous molecular sieve, support precious metal salt or noble metal organic coordination compound, drying also obtains catalyst oxidation thing precursor after 350～500 ℃ of following roastings, this precursor is warming up to 200～400 ℃ with the speed of 1～10 ℃/min in hydrogen atmosphere, under this temperature, reduced 0～5 hour, and prepared the carried noble metal Hydrobon catalyst.

The activity of such catalysts component is group VIII noble metals such as Pt, Pd, Ru, Rh, or alloy or many metal active constituents of above multiple metal formation.The noble metal mass fraction is between 0.1～10% in the catalyst.The Preparation of catalysts method adopts equi-volume impregnating or excessive infusion process.Active component can directly be supported on the silica-based porous carrier materials of silanization modification; Perhaps earlier active component is supported on and makes the oxidation state presoma on the silica-based porous material, again this oxidation state presoma is carried out the silanization modification.Precious metal salt looked by the maceration extract solvent or noble metal organic coordination compound dissolution properties is selected water or toluene, acetone, ethanol, propyl alcohol and glycerine organic solvent, the mixed solvent of perhaps selecting multiple organic solvent to form.The shape of catalyst is sphere, bar shaped, sheet.

Effect of the present invention and benefit are that prepared noble metal catalyst has very high catalytic reaction activity to the aromatic heterocycle sulfur-containing compound in the petroleum distillate under the typical commercial application condition, and have anti-preferably sulphur stability and very low cracking activity, but the deep hydrodesulfurizationof of fraction oil of petroleum is realized on economical and efficient ground, produce clean fuel oil, have wide application prospect.

Description of drawings

Fig. 1 be dibenzothiophenes at Pd/Si-MCM-41 and when doing with the total silicon MCM-41 with the silanization modification of excessive immersion process for preparing to carry out hydrodesulfurization reaction on the Pd catalyst (Pd/MCM-41 (S)) of carrier hydrodesulfurization rate and cracking conversion rate with the variation relation figure in reaction time.■ represents the hds conversion of DBT on Pd/MCM-41 (S) among the figure; The hds conversion of ▲ expression DBT on Pd/MCM-41; represents the cracking conversion rate of DBT on Pd/MCM-41 (S); △ represents the cracking conversion rate of DBT on Pd/MCM-41.

Fig. 2 is that dibenzothiophenes is at Pd/SiO ₂And with the SiO with the silanization modification of equi-volume impregnating preparation ₂Make the Pd catalyst (Pd/SiO of carrier ₂Hydrodesulfurization rate and cracking conversion rate are with the variation relation figure in reaction time when carrying out hydrodesulfurization reaction (S)).■ represents that DBT is at Pd/SiO among the figure ₂(S) hds conversion on; DBT is at Pd/SiO in ▲ expression ₂On hds conversion; represents that DBT is at Pd/SiO ₂(S) cracking conversion rate on; △ represents that DBT is at Pd/SiO ₂On cracking conversion rate.

Fig. 3 be dibenzothiophenes when carrying out hydrodesulfurization reaction at Pt/Si-MCM-41 and on silanization modification Pt/Si-MCM-41 catalyst (Pt/MCM-41 (S)) hydrodesulfurization rate and cracking conversion rate with the variation relation figure in reaction time.■ represents the hds conversion of DBT on Pt/MCM-41 (S) among the figure; The hds conversion of ▲ expression DBT on Pt/MCM-41; represents the cracking conversion rate of DBT on Pt/MCM-41 (S); △ represents the cracking conversion rate of DBT on Pt/MCM-41.

Fig. 4 investigates figure in Pd catalyst (Pd/MCM-41 (S)) the reaction life-span that the total silicon MCM-41 with the silanization modification of excessive immersion process for preparing makes carrier.■ represents the hds conversion of DBT on Pd/MCM-41 (S) among the figure; represents the cracking conversion rate of DBT on Pd/MCM-41 (S).

The specific embodiment

Be described in detail the specific embodiment of the present invention below in conjunction with technical scheme and accompanying drawing.

Embodiment 1

The Pd catalyst precarsor that supports with the total silicon MCM-41 (Si-MCM-41) of excessive immersion process for preparing silanization modification: (molecular sieve/toluene ratio is: 1g molecular sieve/50ml toluene) at first Si-MCM-41 to be placed toluene, add trim,ethylchlorosilane (volumn concentration 5%) then, at 100 ℃ of following stirring and refluxing 6h, suction filtration then, use toluene wash, dry 12h under the room temperature obtains the Si-MCM-41 of silanization modification.The 0.022g palladium is dissolved in the 20ml toluene, the Si-MCM-41 that adds the modification of 1g silanization then, fully stir 10h, suction filtration is used absolute ethanol washing, dry 16h in 120 ℃ of baking ovens, in Muffle furnace, rise to 400 ℃ then with 1 ℃/min, roasting 5h obtains catalyst precarsor, and the loading of Pd is 0.2806wt%.Catalyst is designated as Pd/MCM-41 (S)

Embodiment 2

The SiO for preparing the silanization modification with equi-volume impregnating ₂The Pd catalyst precarsor that supports: at first with SiO ₂Place toluene (SiO ₂/ toluene ratio is: 1g SiO ₂/ 50ml toluene), add trim,ethylchlorosilane (volumn concentration 5%) then, at 100 ℃ of following stirring and refluxing 6h, suction filtration is used toluene wash then, and dry 12h under the room temperature obtains the SiO of silanization modification ₂The 0.022g palladium is dissolved in the 3.5g toluene, and ultrasonic oscillation fully dissolves.The support powder that takes by weighing the modification of 1g silanization joins in the maceration extract, floods 8h under the room temperature, then dry 16h in 120 ℃ of baking ovens, rise to 400 ℃ at Muffle furnace with 1 ℃/min, roasting 5h obtains catalyst precarsor, the loading of Pd is 1wt%, and catalyst is designated as Pd/SiO ₂(S).

Embodiment 3

Prepare the Pt catalyst precarsor that total silicon MCM-41 supports with equi-volume impregnating, again it is carried out the silanization modification: with 0.03g H ₂PtCl ₆Be dissolved in the deionized water of 1.5mL, take by weighing the Si-MCM-41 of 1g then, join in the above-mentioned maceration extract, at room temperature flood 8h, dry 12h in 120 ℃ baking oven in 400 ℃ of roasting 3h, obtains the oxidation state precursor in Muffle furnace.Precursor is placed toluene (precursor/toluene ratio: 1g precursor/50ml toluene), add trim,ethylchlorosilane (volume fraction 5V%) then, at 100 ℃ of following stirring and refluxing 6h, suction filtration then, use absolute ethanol washing, dry 12h obtains catalyst precarsor under the room temperature, the loading of Pt is 1wt%, and catalyst is designated as Pt/MCM-41 (S)

Embodiment 4

Take by weighing the catalyst precarsor among the 0.05

gram embodiment

1,2 or 3, pack into the fixed bed reactors of 8 millimeters of internal diameters, the adjustment Hydrogen Vapor Pressure is 1MPa, hydrogen flowing quantity is 30mL/min, speed with 10 ℃/min is warming up to 300 ℃ in hydrogen atmosphere then, at 300 ℃ of reduction 1h, make corresponding catalyst.

Embodiment 5

After preparing catalyst by embodiment 4 described methods, Hydrogen Vapor Pressure is increased to 5.0MPa, in reactor, carry the decahydronaphthalene solution of the dibenzothiophenes (DBT) of mass content 0.8% then with high-pressure metering pump, be used for product analysis through gas-liquid separator separates fluid body at reactor exit.Other reaction conditions are: liquid air speed (WHSV) is 54h ^-1, H ₂Flow is 30mL/min.Agilent 6890 gas chromatographic analysis of raw material and product.

The desulfurization performance of catalyst DBT hds conversion (x _HDS) expression: x _HDS=(C _{DBT, 0}-C _DBT-C _SI)/C _{DBT, 0}* 100%, in the formula, C _{DBT, 0}And C _DBTBe respectively reactor inlet and exit DBT concentration, mmol/l; C _SIBe the concentration of sulfur-bearing intermediates such as reactor exit tetrahydrochysene dibenzothiophenes and six diphenyl hydrogen bithiophenes, mmol/l.The cracking of catalyst can be represented with low molecular product (benzene and cyclohexane) yield, be designated as x _HDSBy Fig. 1～Fig. 3 as can be seen, Pd/MCM-41 (S), Pd/SiO ₂And the desulphurizing activated and stable catalyst that is significantly higher than without the silanization modification of Pt/MCM-41 (S), and cracking activity significantly reduces, and shows good hydrodesulfurization performance.As seen from Figure 4, Pd/MCM-41 (S) catalyst does not have a significant change in that reaction is desulphurizing activated in the 100h, shows good sulfur tolerance.

Claims

1. the noble metal hydrogenation of anti-sulphur desulphurization catalyst, it is characterized in that, silica, silica-rich zeolite, MCM-41 or SBA-15 silicon-based mesoporous molecular sieve porous silica-base material with the silanization modification are made carrier, support precious metal salt or noble metal organic coordination compound, drying also obtains catalyst oxidation thing precursor after 350～500 ℃ of following roastings, this precursor is warming up to 200～400 ℃ with the speed of 1～10 ℃/min in hydrogen atmosphere, under this temperature, reduced 0～5 hour, and prepared the carried noble metal Hydrobon catalyst.

2. a kind of noble metal hydrogenation of anti-sulphur desulphurization catalyst according to claim 1 is characterized in that, the activity of such catalysts component is Pt, Pd, Ru, Rh group VIII noble metals, or alloy or many metal active constituents of above multiple metal formation.

3. a kind of noble metal hydrogenation of anti-sulphur desulphurization catalyst according to claim 1 is characterized in that the noble metal mass fraction is between 0.1～10% in the catalyst.