CN103831138A

CN103831138A - Preparation method of gamma-alumina supporter with high specific surface area

Info

Publication number: CN103831138A
Application number: CN201410117295.0A
Authority: CN
Inventors: 冉峰; 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: 2014-06-04
Anticipated expiration: 2034-03-27
Also published as: CN103831138B

Abstract

The invention discloses a preparation method of a gamma-alumina supporter with a high specific surface area. The gamma-alumina supporter is applicable to metal supported catalysts. According to the preparation method, pseudo-boehmite powder serves as a raw material and is roasted at low temperatures to prepare the gamma-alumina with the high specific surface area, wherein the specific surface area of the gamma-alumina is greater than or equal to 550m<2>/g; the specific surface area of the pseudo-boehmite powder is greater than or equal to 250m<2>/g; the roasting is multistage constant-temperature roasting and comprises the following stages: roasting for 0.5-2 hours at 150-200 DEG C, roasting for 0.5-2 hours at 300-350 DEG C, roasting for 0.5-2 hours at 360-410 DEG C, roasting for 0.5-2 hours at 500-550 DEG C; the highest roasting temperature in the low-temperature roasting is less than or equal to 550 DEG C. the multistage constant-temperature roasting process adopts the first three stages of roasting or four stages of roasting. The specific surface area of the gamma-alumina supporter is greater than or equal to 500<m>2/g. Duo to the adoption of the multistage constant-temperature roasting method, the roasting temperature is low, so that the structure of the supporter is not easy to damage.

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

Conventionally the preparation of gama-alumina is take boehmite powder as raw material, adds expanding agent and extrusion aid and mixes, in the process of mixing, drip uniformly the aqueous solution of peptizing agent, kneading is to best plastic state, then extrudes, slitting, dry, roasting, finally makes gama-alumina.

In published technology, the baking modes of taking has a variety of, comprising: a step roast method, two-section roasting, three sections of roastings etc., but which kind of baking modes no matter, sintering temperature is all higher.Specific area, aperture and the pore volume of high-temperature roasting meeting on gama-alumina causes bad impact.

Summary of the invention

The object of this invention is to provide a kind of relatively large specific area that has, there is even, suitable aperture and pore volume simultaneously ,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 of taking is: high-specific surface area gamma-aluminium oxide carrier and preparation method thereof, take boehmite powder as raw material, make high-specific surface area gama-alumina through low-temperature bake, and its gamma oxidation aluminum ratio table face amasss≤550 m 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 at 150-200 ℃, roasting 0.5-2 h at 300-350 ℃, roasting 0.5-2 h at 360-410 ℃, roasting 0.5-2 h at 500-550 ℃; The highest sintering temperature≤550 ℃ 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, adopted the method for multistage constant temperature calcining, sintering temperature is lower, makes the structure of carrier be not easy to destroy, and the inventive method preparation technology is simple, easily grasps.

The specific embodiment

Preparation method of the present invention:

First take a certain amount of boehmite powder, physics expanding agent and extrusion aid, join in kneader and mix, in the process of mixing, drip uniformly the aqueous solution of peptizing agent, kneading is to best plastic state, then be extruded into trifolium-shaped bar (diameter 1mm), the segment that is cut into 1cm, at room temperature dries naturally, then dry in 100 ℃ in constant temperature blast drying oven, the article shaped being dried is joined in rotary furnace through multistage constant temperature calcining, finally make 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 ℃ of temperature.Preferably at room temperature open dry 6-12h, then dry 6-10h at 100 ℃ of temperature.

Multistage constant temperature calcining of the present invention is roasting 0.5-2h at 150-200 ℃, roasting 0.5-2h at 300-350 ℃, roasting 0.5-2h at 360-400 ℃, roasting 0.5-2h at 500-550 ℃.The heating rate of multistage constant temperature is 1 ~ 2 ℃/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 (boehmite grain weight amount 1% ~ 3%) and sesbania powder (boehmite grain weight amount 1% ~ 3%) and mix, in the process of mixing, drip uniformly 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 ℃ of temperature.Dried article shaped is placed in to tubular type rotary furnace, roasting 0.5-2h at 150-200 ℃ respectively, roasting 0.5-2h at 300-350 ℃, roasting 0.5-2h at 360-400 ℃, roasting 0.5-2h at 500-550 ℃.Make 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 to mix, 3.3g nitric acid and 6.7g are dissolved in 10g deionized water, and by even to the solution of gained and above-mentioned mixing of materials, kneading is to best plastic state, then on fluid pressure type extruder, be extruded into the directly cloverleaf pattern bar for 3mm, be cut into the segment of 1cm, at room temperature spacious dry 12h, then dry 10h at 100 ℃ of temperature.Dried article shaped is placed in to tubular type rotary furnace, roasting 1h at 170 ℃ respectively, roasting 1h at 310 ℃, roasting 1h at 360 ℃, roasting 1h at 550 ℃.Obtain alumina support A1 provided by the invention.

embodiment 2

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

embodiment 3

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

Example 4

With embodiment 1, just by the cloverleaf pattern bar of extruding, be cut into the segment of 1cm, at room temperature spacious dry 4h, then dry 6h at 100 ℃ 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 to tubular type rotary furnace, roasting 2h at 170 ℃ respectively, roasting 2h at 310 ℃, roasting 2h at 360 ℃, roasting 2h at 550 ℃.Obtain alumina support A5 provided by the invention.

comparative example 1

This comparison example is the alumina support of preparing according to the method for describing in CN1448218A, and concrete preparation method is:

Weighing a water aluminum oxide 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.After fully mixing, be kneaded into plastic shape, be extruded into clover strip (diameter 1.4mm).After air drying spends the night, then dry 2h at 110 ℃.

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

comparative example 2

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

Weigh boehmite dry glue powder (aluminium oxide butt content 65%) 100g; add sesbania powder 2g; carbon powder 3g mixes; 1.5g phosphoric acid is dissolved in 80mL distilled water; by even to gained solution and above-mentioned mixing of materials; on screw rod banded extruder, being extruded into diameter is the cloverleaf pattern bar of 1.8mm; dry 3h in 120 ℃; dried article shaped is placed in to tube type high-temperature furnace; nitrogen blowing 0.75h at 150 ℃ with 600 ℃ of roasting 4h, then stops nitrogen protection and passes into air under the condition of nitrogen protection; at 600 ℃ 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. high-specific surface area gamma-aluminium oxide carrier and preparation method thereof, is characterized in that: take boehmite powder as raw material, make high-specific surface area gama-alumina through low-temperature bake, its gamma oxidation aluminum ratio table face amasss≤550 m 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 at 150-200 ℃, roasting 0.5-2 h at 300-350 ℃, roasting 0.5-2 h at 360-410 ℃, roasting 0.5-2 h at 500-550 ℃;

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

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