CN104248983B - A kind of SiO2-Al2o3the preparation method of complex carrier - Google Patents

Abstract

The present invention relates to a kind of SiO₂‑Al₂O₃The preparation method of complex carrier；Thin for plan water aluminum is put in deionized water, tetraethyl orthosilicate and dehydrated alcohol mixed solution are designated as A, and dehydrated alcohol, deionized water, concentrated nitric acid mixed solution are designated as B, are added drop-wise to solution B in solution A generate colloidal sol, pour in the making beating liquid intending thin water aluminum, obtain complex carrier SiO₂‑Al₂O₃；Dehydrated alcohol deionized water concentrated nitric acid mol ratio 1:9:2:0.3；Intend the mass ratio 1:3 1:4 of thin water aluminum and deionized water；SiO in complex carrier₂Load quality is 5 20%；By Ni₂P loads to SiO₂‑Al₂O₃Complex carrier, can either reflect SiO₂High activity, Al can be made full use of again₂O₃Large ratio surface, character that mechanical strength is high, there is the highest hds conversion to model compound DBT.

Description

A kind of SiO2-Al2O3The preparation method of complex carrier

Technical field

The present invention relates to the SiO of a kind of applicable transition metal phosphide industrialization hydrodesulfurization reaction₂-Al₂O₃Complex carrier.

Background technology

Ni₂P especially SiO₂The Ni of load₂P catalyst has the hydrodesulfurization activity of excellence.But, catalyst for desulphurization of oil products carrier conventional in commercial production is the γ-Al of big pore volume₂O₃.If Ni₂P catalyst is with γ-Al₂O₃For carrier, then Ni in preparation process₂P is easy to and γ-Al₂O₃Carrier surface generates AlPO due to strong interaction₄.This can cause the loss of active component, and even the destruction of catalyst surface texture, makes catalyst activity reduction, limits Ni₂The application in the industry of P catalyst.Big pore volume γ-Al is prepared by methods such as sol-gel processes₂O₃Support SiO₂Nano combined carrier (SiO₂-Al₂O₃), and it is prepared for SiO under cryogenic₂-Al₂O₃The Ni of load₂P catalyst.SiO₂-Al₂O₃Complex carrier is by SiO₂With γ-Al₂O₃The advantage of two kinds of carriers combines, and the most both can give full play to Ni₂P/SiO₂High desulfurization activity, it is also possible to utilize at γ-Al₂O₃The scattered SiO of carrier surface₂Weaken Ni₂P Yu γ-Al₂O₃The strong interaction on surface, can also utilize the big pore volume γ-Al that can be applicable to oil product of mechanical performance and better economy simultaneously₂O₃For carrier.

Summary of the invention

It is an object of the invention to provide the SiO of a kind of transition metal phosphide industrialization hydrodesulfurization reaction₂-Al₂O₃Complex carrier preparation method.Catalyst prepares support type Ni by using nickelous hypophosphite low-temperature thermal decomposition process₂P, examples of such carriers can be effectively prevented P with Al and be combined generation AlPO₄, SiO can either be reflected₂High activity, Al can be made full use of again₂O₃Large ratio surface, character that mechanical strength is high, the Ni of the same amount that examples of such carriers is prepared₂P has the highest hds conversion to oil model thing DBT.

Specifically comprise the following steps that

A kind of SiO of the present invention₂-Al₂O₃The preparation method of complex carrier, it is characterised in that:

Boehmite is put in deionized water, making beating 3h, is designated as A by tetraethyl orthosilicate and dehydrated alcohol mixed solution, and dehydrated alcohol, deionized water, concentrated nitric acid mixed solution are designated as B, it is added drop-wise to solution B in solution A generate colloidal sol, prepared colloidal sol is poured in the making beating liquid of boehmite, quickly stir a period of time, take out and be placed in clean surface plate, naturally dry, put and dry in an oven, be placed on Muffle kiln roasting, obtain complex carrier SiO₂-Al₂O₃；

Described tetraethyl orthosilicate dehydrated alcohol deionized water concentrated nitric acid mol ratio 1:9:2:0.3；

Described boehmite and the mass ratio 1:3-1:4 of deionized water；Optimum is 1:3.5；

Solution A is identical with the dehydrated alcohol usage amount in B solution, is and prepares corresponding SiO₂The half of the tetraethyl orthosilicate amount used of load capacity；

SiO in prepared complex carrier₂Load capacity is 5-20%；Preferably 10%；

The rate of addition of solution B is at 10-30ml/min；Preferably 20ml/min.Mixed solution and boehmite making beating liquid mix and blend time are between 1.0h-3h；The drying temperature of precursor solution is 5-100 DEG C；Precursor sintering temperature is 250-500 DEG C.

Al₂O₃The preferred industrial alumina catalyst support of carrier；The preferred 2-4h of roasting time.

Directly with industry macropore Al₂O₃Precursor AlOOH before roasting is matrix, the SiO of tetraethyl orthosilicate hydrolysis in acid condition₂Cover on AlOOH surface, after roasting, obtain the Al of modification₂O₃, this kind of method is with other method differences preparing complex carrier, and directly using industry macropore AlOOH is matrix, is not to use industry Al₂O₃Or the Al of laboratory synthesis₂O₃For matrix.Explore the method for hydrolysis of the simplest mitigation of tetraethyl orthosilicate simultaneously, make SiO₂Preferably at Al₂O₃Upper dispersion.

Accompanying drawing explanation

The complex carrier SiO of Fig. 1 synthesis₂-Al₂O₃X-ray powder diffraction figure.

Detailed description of the invention

Embodiment 1

Weigh 30g boehmite and 100g water, room temperature making beating 3h.

It is formulated as follows solution:

Tetraethyl orthosilicate (TEOS) dehydrated alcohol deionized water concentrated nitric acid=1:9:2:0.3 (mol ratio) beaker A:12.5ml tetraethyl orthosilicate (TEOS)+15ml dehydrated alcohol (sequential write is addition sequence) beaker B；15ml dehydrated alcohol+2ml deionized water+1ml concentrated nitric acid (sequential write the is addition sequence) half of required ethanol total amount (dehydrated alcohol in beaker A and beaker B be)

It is added drop-wise in beaker A generate colloidal sol with the speed of 20ml/min by the solution in beaker B, prepared colloidal sol is poured in the making beating liquid of boehmite at once, quickly stir 60min, take out and be placed in clean surface plate, naturally 24h is dried, put 120 DEG C of drying 3h in an oven, be placed on 500 DEG C of roasting 4h in Muffle furnace, obtain complex carrier SiO₂-10-Al₂O₃, i.e. SiO in complex carrier₂Mass fraction account for 10% (shown in Fig. 1 b) of complex carrier mass fraction.Ni is prepared by nickelous hypophosphite low-temperature thermal decomposition process₂P load capacity is the catalyst n i of 20%₂P/SiO₂-10-Al₂O₃, it is designated as A.

With the preparation process of catalyst A, change SiO in complex carrier₂Mass fraction account for the 5% of complex carrier mass fraction, prepare Ni₂P load capacity is the catalyst n i of 20%₂P/SiO₂-5-Al₂O₃, it is designated as B.

With the preparation process of catalyst A, change SiO in complex carrier₂Mass fraction account for the 20% of complex carrier mass fraction, prepare Ni₂P load capacity is the catalyst n i of 20%₂P/SiO₂-20-Al₂O₃, it is designated as C.

Embodiment 2

Only change making beating liquid composition, boehmite is changed into γ-Al₂O₃, by 30g γ-Al₂O₃Mix with 100g water making beating 3h, remaining process with the preparation process of catalyst A, SiO in complex carrier₂Mass fraction account for the 10% of complex carrier mass fraction, prepare Ni₂P load capacity is the catalyst n i of 20%₂P/SiO₂-10-γ-Al₂O₃, it is designated as D.

Embodiment 3

Nitric acid is become ammonia, remaining process with the preparation process of catalyst A, SiO in complex carrier₂Mass fraction account for the 10% of complex carrier mass fraction, prepare Ni₂P load capacity is the catalyst n i of 20%₂P/SiO₂-10-Al₂O₃, it is designated as E.

Comparative example 1 removes mashing step, and the carrier preparation process of direct catalyst A prepares SiO₂, prepare Ni₂P load capacity is the catalyst n i of 20%₂P/SiO₂-10-γ-Al₂O₃, it is designated as F.

Comparative example 2 is directly with industry γ-Al₂O₃Ni is prepared for carrier₂P load capacity is the catalyst n i of 20%₂P/Al₂O₃, it is designated as G.

Above-mentioned a few class catalyst are carried out hydrodesulfurization performance evaluation.The HDS of this patent evaluates and carries out on the pressurization static bed continuous flow reactor of homemade tubular type, with dibenzothiophenes as probe, used raw material be mass fraction be 0.3wt% dibenzothiophenes (DBT)/decahydronaphthalene mixed solution, regulation H₂Pressure 3.0Mpa, flow velocity is 150-160ml/min, with 5h_-1Liquid hourly space velocity (LHSV) charging, react at 350 DEG C, reaction conversion ratio situation such as table 1.

Table 1

Catalyst	Dibenzothiophenes conversion ratio
		A	97%
B	69%
		C	73%
D	70%
		E	59%
F	90%
		G	63

Claims (1)

1. a SiO₂-Al₂O₃The preparation method of complex carrier, it is characterised in that:

Being put into by boehmite in deionized water, pull an oar 3h, and tetraethyl orthosilicate and dehydrated alcohol mixed solution are designated as A, Dehydrated alcohol, deionized water, concentrated nitric acid mixed solution are designated as B, are added drop-wise to solution B in solution A generate colloidal sol, will The colloidal sol prepared is poured in the making beating liquid of boehmite, quickly stirs a period of time, takes out and is placed in clean surface plate, Naturally dry, put and dry in an oven, be placed on Muffle kiln roasting, obtain complex carrier SiO₂-Al₂O₃；

Described tetraethyl orthosilicate dehydrated alcohol deionized water concentrated nitric acid mol ratio 1:9:2:0.3；

Described boehmite and the mass ratio 1:3-1:4 of deionized water；

Solution A is identical with the dehydrated alcohol usage amount in B solution, is and prepares corresponding SiO₂Needed for load capacity, ethanol is total The half of amount；

SiO in prepared complex carrier₂Load quality is 5-20%；

The rate of addition of solution B is at 10-30mL/min；Described colloidal sol existed with the boehmite making beating liquid mix and blend time Between 1.0h-3h；The drying temperature of precursor solution is 5-100 DEG C；Precursor sintering temperature is 250-500 DEG C,

Described precursor solution is that colloidal sol dries, after boehmite making beating liquid mix and blend, the product obtained naturally；

Described precursor is the product obtained after described precursor solution is dried.