DE2149897C3 - Spherical catalyst support - Google Patents

Description

DE-AS 1200271 describes a process for the production of mechanically resistant aluminum oxide particles. The aluminum oxide particles obtained in this way have a surface area of 360 m ² / g, a pore volume of 0.57 ccm / g and a high breaking strength insufficient.

DE * AS 12 78412 describes a process for the production of alumina catalyst carriers with high mechanical strength and small specific surface areas. The granules or agglomerates produced by the process of DE-AS 12 78412 have an effective surface area of less than 80 m ² / g. This surface area is too small for the agglomerate to be used effectively for the production of highly active catalysts. Catalysts which are produced from the agglomerate of DE-AS 12 78412 also have insufficient activity in hydrotreatment processes

From DE-AS 1044 776 it is already known so Produce aluminum oxide catalyst carrier by the fact that hydrous aluminum oxide from a Mixture precipitates, which is an aqueous alkaline aluminate solution, an aluminum salt of a mineral acid and a compound selected from the group selected from aldonic acid and aldonate to form a slurry of hydrous alumina, the slurry is filtered and then used to form alumina spheres 20 to 100 in diameter Micron spray dried. According to this process, silicon-containing alumina catalyst supports can be prepared. These carriers can be used in suitable Way numerous catalytically active metals or metal compounds are applied.

If the alumina particles obtained in this known process are used to produce Catalysts for hydrotreatment, it is found that the activity of the catalysts obtained is insufficient and, in particular, that the sulfur content is not is sufficiently reduced, as can be seen from the later comparative examples.

In US-PS 32 64 069 a process for the production of active aluminum oxide is described in the presence of water. With this well-known In the process, the aluminum oxide is compacted into hard balls by movement in drums and then if these spheres are calcined If these spheres are used for the production of catalysts, it can be seen that that the activity of the catalysts is insufficient

All known catalyst supports are therefore unsatisfactory. Either their strength is insufficient or they result in catalysts and their activity not sufficient for hydrotreatment processes

Catalyst supports are required in particular for the production of catalysts which are used in catalytic cracking, in dehydrogenation, in hydrogenation, hydroforming, desulphurisation, the Aromatization and reforming of hydrocarbons can be used. If the known supports are used for the production of such catalysts, so the catalysts, as already indicated, are unsatisfactory for many large-scale industrial processes.

Although the manufacture of catalysts in the form of extruded bodies and / or of pellets has progressed well in recent years There is a need for hydrotreating catalysts with increased activity so that it becomes possible at a given amount of catalyst to obtain a larger amount of product. This could increase productivity and the economy of the various hydrotreatment processes can be increased.

Hydrotreatment processes are, for example, hydrocracking, desulphurisation, hydro-nitrogen elimination, hydrogenations, etc. and, as before indicated, catalysts which contain aluminum oxide supports are generally used for such processes, used

The object of the invention is to provide a catalyst support available that the disadvantages of known catalyst carrier does not have.

The invention is described in the claim.

On the catalyst support according to the invention, in a manner known per se, the in Table I Apply the specified elements by impregnation, the impregnation taking place before or after the compaction in a known manner.

The catalyst obtained using the catalyst support according to the invention has the following properties:

(1) a surface area of 200 to 500 m ² / g, preferably from 300 to 60OmVg,

(2) a pore volume of from 0.50 to 1.2 ccm / g, preferably from 0.75 to 1.0 ccm / g, and

(3) a breaking strength of 0.45 kg to 9.07 kg.

■ The catalyst support according to the invention has a high strength and can after impregnation with active elements are used for catalytic fixed bed processes without increasing the density of the catalysts and, accordingly, the surface area of the Decrease pore volume.

In contrast, if known catalyst supports, which are compressed by extrusion or compression, are used for the production of catalysts, then in the case of such catalysts, if they in the case of fixed bed catalysis processes, the density and the surface area and the pore volume

decrease and the activity of the catalysts deteriorates over time,

The catalyst supports according to the invention produce catalysts which, in comparison with known fixed-bed catalysts have extremely high relative activity based on their weight.

The catalyst supports according to the invention were compared with the catalyst supports known from DE-AS 1044 776. Both catalyst supports were used to produce a catalyst containing molybdenum trioxide and cobalt oxide The properties of the catalysts produced are given below. Both catalysts were then used in the

1. Catalyst, produced using the carrier known from DT-AS 10 44 776:

also the following reaction conditions in a hydrodesulfurization process used

A comparison of the two catalysts shows that using the catalyst support according to the invention produced catalyst reduces the sulfur content more and improves the cetane number more, whereby the ignitability of the product obtained is particularly favorable than the one below Use of the catalyst carrier made known from DT-AS 10 44 776. This is possible from the following comparative tests:

• 5
i Chemical analysis Dry basis Dry basis Catalyst 2 349 (Wt .-%) (Wt .-%) - 0.31750 cm 42.2 MoO ₃ 12.5 12.5 Bullets 213 CoO 3.5 3.5 1145 Alumina base rest 0.08 10.3 hourly weight x space velocity / hour 13.8 Physical Properties: 0.03 349 reactor temperature, C Surface area, m ² / g 280 1.5 42.2 reactor pressure, atm Total pore volume, cc / g 0.58 rest 213 hydrogen (85% recycling), m ^J / m ^J Density, g / ccm 0.68-0.70 Reactor packing density, g / cc 0.62-0.656 270 Breaking Strength, kg 7.26-8.16 0.65 Friction index, percentage, on a sieve of 0.84 mm 95 0.48 remained in the drum after one hour of treatment 6.80 2. Catalyst which is produced using a catalyst support according to the invention: 99 Chemical Analysis MoO ₃ CoO Na ₂ O I Fe I SiO ₂ j Al ₂ O ₃ I physical properties: I surface area, m ² / g : Pore volume, ccm / g j Density (packed), g / ccm I breaking strength, kg I Friction index, percentage, based on a 0.84 mm sieve S remained in the drum for one hour y
Catalyst 1 process conditions during the test : 0.31750 cm • Compact 1050 loading, m ³ per day

Catalyst 1
0.31750 cm
Compact

Results

Catalyst 2
0.31750 cm
Bullets

Feed sulfur content, weight% sulfur content of product, wt% cetane number (feed)
Cetane number (end product)

3.1

0.9

21.1

27.6

The catalyst supports according to the invention must meet 2 main conditions:

(1) The spherical catalyst carrier must be made by densifying alumina microspheres that have a surface area of about 200 to about 500 mVg and a pore volume of about 0.25 to about 1.5 ccm / g, and

(2) The alumina microspheres must be subjected to a densification process such as using a Wab, - or drum device, to be deformed into spherical bodies, that is a sufficient Compaction results in the microspheres having a force hold together that spherical body with a breaking strength of about 0.45 kg to about 9.07 kg and without densifying the microspheres to a point where the Surface of the compacted spherical body below 200 mVg or the pore volume of the compacted spherical bodies are below 0.50 ccm / g.

It is compressed in such a way that the mass density of the spherical catalyst support is not greater than Ms Is 0.50 g / cc, and is preferably in the range of 0.15 to 0.50 g / cc, most preferably in the range of 0.20 to 0.40 g / cc.

In a further preferred embodiment, the spherical catalyst support has a central one Bulk density from 03 to about 0.6 g / ccm.

The alumina microspheres suitable for the manufacture of the catalyst support according to the invention can be made from either essentially pure alumina or from silica-alumina mixtures exist, which have a high aluminum oxide content. All of these mixes are in the commonly referred to as alumina support. Suitable mixtures and processes for making the Microspheres are described in U.S. Patents 2,996,460, 2,988,520, and 3,520,654, for example.

In these patents, suitable procedures for the production of aluminum oxide and / or silica-alumina microspheres described, but it is not important to the invention that the microspheres, which are compressed to form the spherical catalyst carrier, after a certain processes are produced. It is only essential that the microspheres before the Compaction have the characteristic physical properties given above.

Table 1

Catalytically active metals based on the
Catalyst supports can be deposited

One or more of the following:

15th

20 mn

Mon

re

Ir

Os

Pt

Pb

Bi

Rare earth

Manufacturing example of aluminum oxide microspheres, which can be used in the production of a catalyst support according to the invention:

II. To 60 000 g of tap water 42 g 50% gluconic acid, 23 g sodium silicate (28.5% SiO ₂ and 9% Na ₂ G) and 4175 g of sodium aluminate (24.5% AI ₂ Oj and 19% Na ₂ O ) given. Then, over a period of 22 min, 382 g of sulfuric acid of 66 ° Be, which with

JO 8132g of water have been added to the above mixture at a temperature of 46.7 ° C. Then over a period of 29 min 4116 g of an aluminum sulfate solution with 7.5 wt .-% Al ₂ Os, which has been further diluted with 7256 g of water,

J5 added. The pH is around 9.0. the The resulting slurry is then filtered, and the resulting filter cake is replenished with water slurried, whereby a pumpable 'mixture is obtained. This mixture is used to form Alumina-silica microspheres spray dried. The dried microspheres are made with washed with hot water (48.9 ° C) to remove soluble salts and dried again.

II. 42 g of 50% gluconic acid, 116 g of sodium silicate (28.5% SiO ₂ , 9% Na ₂ O) and 3500 g of sodium aluminate (24.5% Al ₂ O ₃ and 19% Na ₂ O) given. Over a period of 22 minutes 568 g of sulfuric acid by 66 ° Be, which are diluted with 11,920 grams of water, -to the above mixture at a temperature of 46.7 ⁰ C are then added over a period of 29 min 2405 g an aluminum sulfate solution with 7.5% Al ₂ O3 was added, which was further diluted with 4328 g of water. The pH is around 8.5 to 8.7. The resulting

The slurry is then filtered and the resulting Filter cake is reslurried with water to give a pumpable mixture. This Mixture is used to form alumina-silica microspheres spray dried. The dried microspheres are washed with hot water (48.9 ° C) washed to remove soluble salts and dried again.

Ni
Co
Fe

Sn
W.
Mg

Example!

This example describes the production of a catalyst support according to the invention.

The alumina microspheres from I have the following properties:

Pore volume 0.86 ccm / g

Apparent mass density 0.50g / ccm surface 365

The microspheres are compacted into spherical structures with a diameter of 3.17 mm by a process in which the microspheres are tumbled on top of one another in contact with water . The resulting spherical bodies have a breaking strength of approximately 1.81 kg. after being dried at a temperature of 49 ° C. They have the following characteristics.

Pore volume <). 7 ^r > ccm / g

Apparent bulk density 0.5 5 g'ccm Oberfkuhc 295 m- / g

H e ι s ρ ι e I 2

The aluminum oxide microspheres prepared according to II i.e. the following properties are available:

Pore volume 0.47 ccm / g

Apparent mass density 0.29 g / ccm surface area 385 m - '/ g

The microspheres are as described in Example 1, deformed into spherical catalyst carriers. The resulting, spherical bodies had breaking strengths from! .3b to 2.27 kg and the following f.iger.si.haft.

Pore volume 0.9 3 ccm / g

Apparent density of misses 0.38 g / ccm Oherflache 37Om-Vg

HerMe-

Of the

\. '. irr ..
cr eel!

üungsbeispiel f ^ur a catalyst erfindimijsgeniäßen catalyst support

xiii-carrier according to example 2 is d Mlbd

.. -r.ur

Ά ·. · Tr;

.τι s: c ge

.deride

ige :. l .-> s'ing of cobalt and molybdenum ragru :. r. IaB a final content of 4.05% Co Mo.,:. '■■ _ ■ -.' Pushes as oxides after a ng be -.-'- Aa M 9 C. is obtained. Aftermath m; are impregnated with the solution. ■ rock η: .- · and ν. a glue. .! Jisc ^ eP F-. Properties of the Catalyst

F'orer.volumer:
Apparent Must

right

0.45 g / cc

Table 3

Behavior as F.ntnitn ^ enisieruneskatalvsator

surface Breaking strength Cobalt content Molybdenum content

235 mVg 2.27 kg 4.05 wt% l3.8% by weight

Comparative experiment 1

The catalyst according to the previous example and a typical catalyst with 3.17 mm in the form of an extruded body made of cobalt and molybdenum , Ulf an Aliiminiumoxid-Orundlagc. made from microspheres. which correspond to the microspheres of production II were examined in a gas oil desulphurisation process. The extruded body which was examined had a diameter of 17 mm and the following physical properties:

Pore volume

Apparent mass density

surface

Breaking strength

Cobalt content

Molybdenum content

0.51 cc / g
0.69 g / cc
270 m-7g
6.35 kg
3.5 wt%
12.5% by weight

The specific weight related activities that were obtained are listed below.

Table 2

Catalyst in the carrier
according to example 2

Catalyst consisting of
the extruded body

2.4 l.n

Comparative experiment 2

As described in Example 1, spherical catalyst supports were produced, with the exception. that the balls had a diameter of 1.58 mm. These balls were impregnated with nickel and molybdenum and compared with an extruded catalyst with a diameter of 1.58 mm, which had been produced from the microbeads according to II and which had a diameter of 1.58 mm. In a typical denitrogenization process, the physical properties and the relative activity of the catalysts, based on weight, were compared with the known catalysts. The results obtained are shown in Table III.

Relative activity based on weight

Apparent mass density, g / ccm breaking strength, kg

Surface. mVg

Pore volume, cc / g

Wt% Mo

Wt .- ^ Λ Ni

With spherical Catalyst consisting of Catalyst carrier an extruded body 2.4 1.8 0.5 0.74 1.36-2.27 6.35 265 270 0.7 0.51 17.8 14.0 3.9 2.8

The comparative experiments / own that one with the inventive catalyst supports catalysts that have a very high level of activity.

The catalyst activity can be expressed, for example, in denitrogenation by the following formula:

A =

In (No / N) 0.957

tv.

Na = nitrogen in starting material, ppm.

, V = nitrogen in product, ppm.

I = time.

ν = flow rate.

The desulphurisation activity is expressed by the following formula:

A = --J ₁ - ^ t-- ■ t ■ ρ ■ r.

So = weight percent sulfur in the starting material,

S - weight percent sulfur in the product, ρ = pressure factor.

As can be seen from the above formula, the activity of the catalyst under certain flow conditions is expressed as a relationship between the amounts of elements of the The starting material and the product are determined. That

In principle, the process consists in that under certain operating conditions (e.g. 316 ° C., 38.0) atü a fixed catalyst bed is used. prior to blowing out the catalyst with nitrogen, a commercial oil with a fixed flow rate

lets π pass through the catalyst. Product samples are then taken at set times and the corresponding element values are determined therein by elemental analysis. The crhiihener in Dihydrogcnisierung: Meßwens ents ⁿ rcchen kinriKrhon a first order equation, while the kinetic equations F.ntschwcfelungsmeßwerte / recommend corresponding order.

Claims (1)

Claim: Spherical catalyst support, produced by precipitation of hydrous aluminum oxide from a mixture which contains an aqueous, alkaline aluminate solution, an aluminum salt of a mineral acid and a compound from the group of aldonic acid and aldonate, a slurry of hydrous aluminum oxide being produced which is used to increase the concentration ι ο tration of the aluminum oxide solids to 4 to 7 wt .-% Al2O3 is filtered and spray-dried, obtained by washing and re-dried microspheres, which have a surface area of 200 m ² / g to 500 mVg and a before compaction Must have pore volumes of 0.25 ccm / g to 1.5 ccm / g, to spherical structures with a diameter of 0.25 mm to 12.70 mm and a mass density not greater than 03 g / ccm in the presence of water by application a roller or drum device is compacted, and the balls are dried at temperature and time conditions that are sufficient to achieve a breaking strength from 0.45 to 9.07 kg. 25th