CN103831138B

CN103831138B - A kind of preparation method of high-specific surface area gamma-aluminium oxide carrier

Info

Publication number: CN103831138B
Application number: CN201410117295.0A
Authority: CN
Inventors: 冉锋; 姜艳; 周全凯
Original assignee: LIAONING KELONG FINE CHEMICAL CO Ltd
Current assignee: LIAONING KELONG FINE CHEMICAL CO Ltd
Priority date: 2014-03-27
Filing date: 2014-03-27
Publication date: 2015-09-23
Anticipated expiration: 2034-03-27
Also published as: CN103831138A

Abstract

Be suitable for a preparation method for a kind of high-specific surface area gamma-aluminium oxide carrier of metal load type catalyst, with boehmite powder for raw material, obtain high-specific surface area gama-alumina through low-temperature bake ,≤550m is amassed in its gamma oxidation aluminum ratio table face ²/ g.Described boehmite powder is Bi Biao Mian Ji≤250m ²/ g; Wherein roasting is multistage constant temperature calcining, that is: roasting 0.5-2h at roasting 0.5-2h, 500-550 DEG C at roasting 0.5-2h, 360-410 DEG C at roasting 0.5-2h, 300-350 DEG C at 150-200 DEG C; The highest sintering temperature≤550 DEG C of low-temperature bake; Described multistage constant temperature calcining adopts first three section of roasting or four sections of roastings.Gamma-aluminium oxide carrier specific area>=500m prepared by the present invention ²/ g, have employed the method for multistage constant temperature calcining, sintering temperature is lower, makes the structure of carrier be not easy to destroy.

Description

A kind of preparation method of high-specific surface area gamma-aluminium oxide carrier

Technical field

The present invention relates to a kind of a kind of gama-alumina preparation method for fields such as petrochemical industry, chemical industry, environmental protection, be particularly suitable for the preparation method of a kind of high-specific surface area gamma-aluminium oxide carrier of metal load type catalyst.

Background technology

The preparation of usual gama-alumina is with boehmite powder for raw material, and interpolation expanding agent and extrusion aid mix, in the process of mixing, the aqueous solution of uniform dropping peptizing agent, kneading to best plastic state, then extrude, slitting, drying, roasting, finally obtained gama-alumina.

In published technology, the baking modes taked has a variety of, comprising: a step roast method, two-section roasting, three sections of roastings etc., but no matter which kind of baking modes, and sintering temperature is all higher.High-temperature roasting can cause bad impact to the specific area of gama-alumina, aperture and pore volume.

Summary of the invention

The object of this invention is to provide and a kind of there is relatively large specific area, have evenly simultaneously, suitable aperture and pore volume ,through the preparation method of a kind of high-specific surface area gamma-aluminium oxide carrier of low-temperature bake.

For realizing object of the present invention, the technical scheme taked is: the preparation method of high-specific surface area gamma-aluminium oxide carrier, with boehmite powder for raw material, obtains high-specific surface area gama-alumina through low-temperature bake, and≤550 m are amassed in its gamma oxidation aluminum ratio table face ²/ g.Described boehmite powder is Bi Biao Mian Ji≤250 m ²/ g;

Described roasting is multistage constant temperature calcining, that is: roasting 0.5-2 h, roasting 0.5-2 h at 300-350 DEG C, roasting 0.5-2 h at 360-410 DEG C, roasting 0.5-2 h at 500-550 DEG C at 150-200 DEG C; The highest sintering temperature≤550 DEG C of described low-temperature bake; Described multistage constant temperature calcining adopts first three section of roasting or four sections of roastings.

The invention has the beneficial effects as follows: gamma-aluminium oxide carrier specific area>=500m prepared by the present invention ²/ g, has again suitable pore volume and aperture simultaneously.Be particularly suitable for preparing many metal load type catalysts, have employed the method for multistage constant temperature calcining, sintering temperature is lower, and make the structure of carrier be not easy to destroy, the inventive method preparation technology is simple, easily grasps.

Detailed description of the invention

Preparation method of the present invention:

First a certain amount of boehmite powder, physics expanding agent and extrusion aid is taken, join in kneader and mix, in the process of mixing, the uniform aqueous solution dripping peptizing agent, kneading is to best plastic state, then trifolium-shaped bar (diameter 1mm) is extruded into, be cut into the segment of 1cm, at room temperature naturally dry, then in constant temperature blast drying oven in 100 DEG C of dryings, article shaped complete for drying is joined through multistage constant temperature calcining in rotary furnace, finally obtained gama-alumina.

Boehmite powder described in the inventive method is Bi Biao Mian Ji≤250m ²/ g, pore volume 0.7-0.9mL/g.Described physics expanding agent is gas-phase silica.The addition of physics expanding agent is 1% ~ 3% of boehmite grain weight amount, preferably 1%.Described extrusion aid is sesbania powder.Extrusion aid addition is 1% ~ 3% of boehmite grain weight amount, preferably 1%.Described peptizing agent is nitric acid and/or acetic acid.The addition of peptizing agent is 0.1% ~ 0.3% of boehmite grain weight amount, preferably 0.1%.

Dry run of the present invention is generally at room temperature spacious dry 4-16h, then dry 4-16h at 100 DEG C of temperature.Preferably at room temperature open dry 6-12h, then dry 6-10h at 100 DEG C of temperature.

Multistage constant temperature calcining of the present invention is roasting 0.5-2h at roasting 0.5-2h, 500-550 DEG C at roasting 0.5-2h, 360-400 DEG C at roasting 0.5-2h, 300-350 DEG C at 150-200 DEG C.The heating rate of multistage constant temperature is 1 ~ 2 DEG C/min.

The concrete preparation method of high-specific surface area gamma-aluminium oxide carrier of the present invention is: weigh a certain amount of boehmite powder, gas-phase silica powder (1% ~ 3% of boehmite grain weight amount) and sesbania powder (1% ~ 3% of boehmite grain weight amount) and mix, in the process of mixing, uniform dropping nitric acid and/or second aqueous acid, kneading is to best plastic state, then extrude, slitting, at room temperature spacious dry 6-12h, then dry 6-10h at 100 DEG C of temperature.Dried article shaped is placed in tubular type rotary furnace, respectively roasting 0.5-2h at roasting 0.5-2h, 500-550 DEG C at roasting 0.5-2h, 360-400 DEG C at roasting 0.5-2h, 300-350 DEG C at 150-200 DEG C.Obtained final gamma-aluminium oxide carrier.

embodiment 1

Weigh boehmite powder (Bi Biao Mian Ji≤250m ²/ g, pore volume 0.7-0.9mL/g) 1000g, add meteorological white carbon 10g, sesbania powder 10g mixes, 3.3g nitric acid and 6.7g are dissolved in 10g deionized water, the solution of gained and above-mentioned mixing of materials is even, and kneading is to best plastic state, then be extruded on fluid pressure type extruder is directly the cloverleaf pattern bar of 3mm, be cut into the segment of 1cm, at room temperature spacious dry 12h, then dry 10h at 100 DEG C of temperature.Dried article shaped is placed in tubular type rotary furnace, respectively roasting 1h at 170 DEG C, roasting 1h at 310 DEG C, roasting 1h at 360 DEG C, roasting 1h at 550 DEG C.Obtain alumina support A1 provided by the invention.

embodiment 2

With embodiment 1, the addition being gas-phase silica powder is 20g, the addition of sesbania powder is 20g, and other condition is constant, obtains alumina support A2 provided by the invention.

embodiment 3

With embodiment 1, be just dissolved in 10g deionized water by 5g nitric acid and 5g, other condition is constant, obtains alumina support A3 provided by the invention.

Example 4

With embodiment 1, the cloverleaf pattern bar just will extruded, is cut into the segment of 1cm, at room temperature spacious dry 4h, then dry 6h at 100 DEG C of temperature.Other condition is constant, obtains alumina support A4 provided by the invention.

embodiment 5

With embodiment 1, just dried article shaped is placed in tubular type rotary furnace, respectively roasting 2h at 170 DEG C, roasting 2h at 310 DEG C, roasting 2h at 360 DEG C, roasting 2h at 550 DEG C.Obtain alumina support A5 provided by the invention.

comparative example 1

This comparison example is the alumina support prepared according to the method described in CN1448218A, and concrete preparation method is:

Weighing a Water oxidize aluminium dry glue powder 200g(contents on dry basis is 68w%), add 4.0g potassium chloride, 3.0ml acetic acid, 155ml nitric acid (3%) and appropriate water.Abundant mixing, be kneaded into plastic shape after be extruded into clover strip (diameter 1.4mm).After air-dried overnight, then dry 2h at 110 DEG C.

Drying sample is placed in high temperature furnace, is warming up to 200 DEG C with 3 DEG C/min speed, be then warming up to 485 DEG C and constant temperature calcining 2.0h at such a temperature with 4 DEG C/min speed, then be warming up to 600 DEG C with 4 DEG C/min speed and constant temperature calcining 1.5h at such a temperature.This obtains alumina support A6.

comparative example 2

This comparison example is the alumina supporter with high specific surface area according to describing in CN102861619A, and concrete preparation method is:

Weigh boehmite dry glue powder (aluminium oxide contents on dry basis 65%) 100g; add sesbania powder 2g; carbon powder 3g mixes; 1.5g phosphoric acid is dissolved in 80mL distilled water; by gained solution and above-mentioned mixing of materials even; screw rod banded extruder is extruded into the cloverleaf pattern bar that diameter is 1.8mm; 3h is dried in 120 DEG C; dried article shaped is placed in tube type high-temperature furnace; at 150 DEG C, nitrogen purges 0.75h, with 600 DEG C of roasting 4h under the condition of nitrogen protection, then stops nitrogen protection passing into air; at 600 DEG C of roasting 1h, obtain alumina support A7.

Table 1 support

Numbering	A1	A2	A3	A4	A5	A6	A7
								Specific area m ²/g	597	603	601	599	605	430	188

Claims

1. a preparation method for high-specific surface area gamma-aluminium oxide carrier, is characterized in that: with boehmite powder for raw material, obtains high-specific surface area gama-alumina through low-temperature bake, and≤550 m are amassed in its gamma oxidation aluminum ratio table face ²/ g;

Described boehmite powder is Bi Biao Mian Ji≤250 m ²/ g;

Described roasting is multistage constant temperature calcining, that is: roasting 0.5-2 h, roasting 0.5-2 h at 300-350 DEG C, roasting 0.5-2 h at 360-410 DEG C, roasting 0.5-2 h at 500-550 DEG C at 150-200 DEG C;

The highest sintering temperature≤550 DEG C of described low-temperature bake.

2. the preparation method of a kind of high-specific surface area gamma-aluminium oxide carrier according to claim 1, is characterized in that: described multistage constant temperature calcining adopts first three section of roasting or four sections of roastings.