JPS58216740A - Manufacture of gamma-alumina catalyst carrier - Google Patents

Abstract

PURPOSE:To enable control of pore diameter in the carrier of a catalyst, by treating Boehmite sol obtd. by treating aluminum salt or aluminate, by addition of acid or alkali. CONSTITUTION:Boehmite sol is obtained by neutralyzing aluminum salt or aluminate or double decomposing it or hydrolyzing aluminum amalgam or aluminum alcoxide with water or steam. This Boehmite sol is subjected to hydrothermal treatment at 100-300 deg.C in raised pressure by adding acid or alkali to the sol to control pH to 8-11. At least 2 kinds of Boehmite sol thus obtd. are mixed and freed from water in a dryer and molded.

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing an alumina catalyst carrier.

Conventionally, heavy oil such as the residue after distilling crude oil or tar sand oil is hydrotreated to make it lighter, and at the same time, the sulfur compounds contained in the heavy oil are removed.

Efforts are being made to reduce nitrogen compounds, organometallic compounds, etc.

Catalysts are generally used in such hydrotreating, but
An alumina support is well known as a support for this, and a hydrogenation catalyst is prepared by supporting an active metal on this support.As mentioned above, in the hydrogenation process, hydrogen cracking, The activity of the catalyst is selective because it carries out reactions such as desulfurization, demetallization, denitrification, and deoxygenation.

Needless to say, lifespan 2 strength etc. are important keys. It is generally believed that the size and pore distribution of the pores of the catalyst play a major role in the characteristics of the catalyst.

From this point of view, various methods have been proposed to control the pore diameter and pore volume of alumina carriers, and the representative method is the addition of organic substances.

These are an alcohol treatment method and an acid treatment method. An overview is given below.

The method for producing r-alumina is to generate boehmite (A100H) dino r by neutralizing or exchange decomposition of aluminum salts or aluminates, or by hydrolyzing aluminum amalgam or aluminum alkoxide with water or steam, and then heat it at 500°C to The method involves baking at 900°C (generally 600°C).The method of adding organic substances is a method of adding water-soluble organic polymers such as polyethylene glycol, polyvinyl alcohol, and polyacrylamide to control the pore size. . The effects on pore distribution and pore volume when these are added vary depending on the type of additive, and the effects also vary depending on whether they are added immediately after the boehmite sol is formed or after drying. However, there is a drawback that although it is effective for controlling pore volume, it is not effective for controlling pore diameter.

The alcohol treatment method is a method in which the boehmite sol immediately after generation is washed with various alcohols to control the pore diameter. In this case, ethyl alcohol, isopropyl alcohol, and n-butyl alcohol are highly effective, but alcohols with a larger molecular weight than hexyl alcohol
If Lt is used, no effect will be recognized. This method has a narrow controllable width when controlling the pore diameter, and it is not possible to create pores with a diameter of 150 Å or more.

The acid treatment method is a method in which the pore size is controlled by adding an acid to the generated boehmite sol, dehydrating it, molding it, drying it, and firing it, and in this method, the pore size shifts to the smaller side.

As described above, in the conventional method, the control range of the pore diameter is narrow, and the achievable pore diameter (diameter) is limited to about 150 to 200. Moreover, the pore distribution was centered around a certain size.

The present inventors have described a method for preparing r-alumina having a distribution of pore sizes of two or more. As a result of intensive research, the phi of the boehmite sol was adjusted to 8 to 11, and the temperature was further increased to 1.
It has been discovered that the object can be achieved by mixing two or more types of boehmite sols that have been hydrothermally treated at 00 to 800 DEG C. under pressure, and based on this knowledge, the present invention has been completed.

In other words, the present invention is a boehmite sol obtained by neutralizing or exchange decomposing aluminum salts or aluminates, or by hydrolyzing aluminum amalgam or aluminum alkoxide with water or steam, and adding an acid or alkali to the boehmite sol to give a PTT of 8 to 11. Two or more types of boehmite sols that have been hydrothermally treated under pressure at a temperature of 100 to SOO°C are mixed.

The present invention proposes a method for producing an alumina carrier, which is characterized by dehydration, molding, drying, and sintering.

The method of the present invention will be explained in detail below.

In the present invention, the above-mentioned conventional methods are used as starting materials and preparation methods for preparing boehmite gel.

The pH of boehmite gel is adjusted by adding acid or alkali, but there are no particular restrictions on the type.

The hydrothermal treatment temperature is 100°C or higher, preferably 120°C or higher. Further, from the state of the alumina-water system and the relation between temperature and water vapor pressure, the upper limit temperature at which boehmite can be stably produced is considered to be about 800°C, but the practical upper limit is 250°C.

Furthermore, the longer the hydrothermal treatment time, the larger the pore size can be obtained.

After hydrothermally treating the boehmite sol in this way, the boehmite sol hydrothermally treated under two or more conditions is mixed, dehydrated, molded, dried and fired to form two or more
An alumina support having a maximum distribution at a pore size of E is obtained. In the dehydration operation, the boehmite sol that has been hydrothermally treated under two or more conditions is mixed, and then the water is evaporated from the boehmite sol in a dryer or an evaporator.

Up to the moisture content suitable for molding (the ratio of water to solid content is 2
0-80 wt%).

By the method of the present invention, it is possible to increase the pore diameter and pore volume of the r-alumina catalyst carrier, it is also possible to control the pore diameter, and it is also possible to control the pore diameter at two pore diameter positions. An r-alumina catalyst support having a maximum can be obtained.

Next, the effects of the present invention will be explained in more detail with reference to Examples.

Example 1 Aluminum isopropoxide A I (QC!sH?
) 200g of B was dissolved in tooOn+j distilled water kept at 80°C to perform hydrolysis. After that, in order to examine the pH conditions for hydrothermal treatment, IN hydrochloric acid or IN potassium hydroxide aqueous solution was added to adjust the pH to 6.7, 8.
9.10.11.12.18 prepared in 8 types.

Hydrothermal treatment was performed at 150°C for 24 hours.

Thereafter, the boehmite sol obtained in this way was
After extrusion granulation into IIIfflO and drying.

A prototype r-alumina catalyst carrier was produced by firing at 600° C. for 2 hours, and the pore diameter distribution and pore volume were measured. The results are shown in Figures 1 and 2.

FIG. 1 is a graph showing the relationship between pH and pore diameter, where the horizontal axis shows pH and the vertical axis shows pore diameter.

Figure 2 is a graph showing the relationship between pH and pore volume.
The horizontal axis shows pH and the vertical axis shows pore volume.

As is clear from FIGS. 1 and 2, the pore diameter of the γ-alumina catalyst carrier is the same when the pH is between 8 and 11.

It was found to be effective in increasing pore volume.

Implementation P+ 2゜Aluminum sulfate (AI2(SO4)a) 100 g
Dissolve in too much distilled water and add IN hydroxide l-'
A test was conducted by changing the temperature of the hydrothermal reaction of the boehmite sol obtained by adjusting the pH to 10 by adding a Jium aqueous solution and paying attention to the change in pore diameter.

The hydrothermal treatment temperature in this case was 12 o'c, 150°C.

Hydrothermal treatment was carried out in five ways: 180°C, 210°C, and 240°C, and the hydrothermal treatment time was all 24 hours. The hydrothermally treated boehmite sol was granulated in the same manner as in Example 1, then dried and fired to determine the pore diameter. The measurement results of the pore diameter of the obtained r-alumina catalyst carrier are shown in FIG.

In FIG. 8, the horizontal axis shows the hydrothermal treatment temperature, and the vertical axis shows the pore diameter. As is clear from FIG. 8, it is possible to control the pore diameter of the r-alumina catalyst carrier by changing the hydrothermal treatment temperature.

Example 8 Aluminum isopropoxide (AI (008H7)
a) Hydrolysis was carried out by dissolving 200 g in 1000 m/m of distilled water maintained at 80°C. Then 0. After adjusting the pH to 9 by adding IN potassium hydroxide aqueous solution, 15
Water treatment was carried out at 0°C for 10,20,40,60,80,100 hours, a γ-alumina catalyst carrier was prepared in the same manner as in Example 1, and the pore diameter was measured. Figure 4 shows the pore diameter measurement results.

In FIG. 4, the horizontal axis is the hydrothermal treatment time, and the vertical axis is the pore diameter. It can be seen from FIG. 4 that the pore diameter of the r-alumina catalyst carrier can also be controlled by changing the hydrothermal treatment time.

Example 4 Using the boehmite sol obtained by the hydrothermal treatment in Example 8, equal amounts of the two types of sols were mixed, and pellets of r-alumina catalyst carrier were prepared in the same manner as in Example 1. Pore distribution was measured by mercury intrusion method.

FIG. 5 is a graph showing the pore distribution of an r-alumina catalyst carrier obtained by mixing boehmite sol without hydrothermal treatment and boehmite nol subjected to hydrothermal treatment for 60 hours. In FIG. 5, the vertical axis is the cumulative pore volume, and the horizontal axis is the pore diameter. 60
A γ-alumina support with distribution maxima at two pore size positions of 1 and 400 was obtained.

Next, FIG. 6 is a graph showing the pore distribution of an alumina carrier obtained by mixing a boehmite sol subjected to a 10-hour hydrothermal treatment and a boehmite sol subjected to a 60-hour hydrothermal treatment.

In FIG. 6, the vertical axis is the cumulative pore volume, and the horizontal axis is the pore diameter.

An r-alumina catalyst support was obtained with distribution maxima at two pore diameters of 200 and 400.

Example 6 1000 g of sodium aluminate (NaAlO2)
After dissolving in distilled water of No. 07, IN sulfuric acid was added to make the boehmite acidic to a pH of 4 to obtain a boehmite sol.

Next, an aqueous IN sodium hydroxide solution is added to adjust the pH to 9. The boehmite sol thus obtained was heated to 180°C.
5 in a stirred autoclave under saturated steam pressure,
10.20.40.After hydrothermal treatment for 80 hours, water was removed to 25%, extruded into 1.61Illa pellets, granulated, dried and then calcined at 600°C for 2 hours to obtain an alumina catalyst carrier. Ta.

The pore diameter distribution of these r-alumina catalyst carriers was measured by mercury porosimetry. The results are shown in FIG. In this case as well, results very similar to those shown in FIG. 4 in Example 8 were obtained. Here, we reconfirmed that the pore size of the alumina carrier can be increased by hydrothermally treating the boehmite sol before granulation.

Next, as in Example 4, the pore diameter distribution of the r-alumina catalyst carrier obtained by mixing equal amounts of boehmite sol that has not been hydrothermally treated and boehmite sol that has been hydrothermally treated for 20 hours is shown in Figure 8. .

In FIG. 8, the vertical axis is the cumulative pore volume, and the horizontal axis is the pore diameter. A γ-alumina support was obtained with distribution maxima at two pore size positions of 50 and 850.

Furthermore, FIG. 9 shows the pore diameter distribution of an r-alumina catalyst carrier obtained by mixing 8 equal amounts of boehmite sol that had been hydrothermally treated for 5 hours, 10 hours, and 20 hours. In FIG. 9, the vertical axis is the cumulative pore volume, and the horizontal axis is the pore diameter. As is clear from the second figure (170 people, 25OA,
A γ-alumina catalyst support having a distribution maximum at 850 A and 8 pore diameters was obtained.

[Brief explanation of drawings]

FIG. 1 is a graph showing the relationship between the pH of boehmite sol and the pore diameter of the r-alumina catalyst carrier, and FIG. 2 is a graph showing the relationship between the pH of the boehmite sol and the pore volume of the r-alumina catalyst carrier. FIG. 8 is a graph showing the relationship between the hydrothermal treatment temperature of boehmite sol and the pore diameter of the catalyst carrier of 1-7 Jl/j. Figures 4 and 7 show the hydrothermal treatment time and r of boehmite sol.
- a graph showing the relationship with the pore diameter of the alumina catalyst carrier;
FIG. 5, FIG. 6, FIG. 8, and FIG. 9 are graphs showing the relationship between the pore diameter and cumulative pore volume of the r-alumina catalyst carrier. Fig. 1 M Fig. 2 βli- Day 3 Fig. 4 Suitsuki 9 Ginho (Wanii) 58 1S Exit 6 Field Y4 Diameter (B) Fig. a Circle Fig. 9 δ Field SL road (Ono

Claims (1)

[Claims] Add acid or alkali to boehmite sol obtained by neutralizing or exchange decomposition of aluminum salts and aluminates or hydrolyzing aluminum amalgam or aluminum alkoxide with water or steam to adjust the pH to 8 to 11 at a temperature of 100 to 800. A method for producing an alumina carrier, which comprises mixing two or more types of boehmite sol that have been hydrothermally treated under pressure at °C, followed by dehydration, molding, drying, and firing.