DD203068A1 - PROCESS FOR PREPARING ZEOLITHALTIC HYDROSPECT CATALYSTS WITH IMPROVED PORENCE STRUCTURE - Google Patents

Abstract

Process for the preparation of hydrocracking catalysts with improved pore structure. It should be achieved an improvement in the catalytic effect, in particular a reduction in the production of low-boiling hydrocarbons in the hydrocracking of heavy raw materials. This was to be achieved by a special design of the pore structure by targeted influencing during the deformation process. By adding 2 to 10% by mass of SiO & ind2! As low-alkali silica sol and 1 to 10 mass% of a plasticizer, and extrusion molding, a pore distribution with a maximum of the pore volume in the range of pore radius of 100 to 500nm is obtained. The advantages of the process are particularly evident in the case of catalyst moldings which have a geometric surface area to volume ratio of> equal to 9. The process is generally applicable to the preparation of hydrocracking catalysts.

Description

VEB Leuna-Werke Leuna, the 17 "9th 1981

"Walter Ulbricht"

LP 7601-A

Title of the invention

Preparation of zeolite-containing hydrocracking catalysts with improved pore structure

Field of application of the invention

The invention relates to a process for the preparation of zeolite-containing hydrocracking catalysts with improved pore structure, which are used for the production of hydrocarbons with a lower short-chain fraction.

Characteristic of the known technical solutions

Purely the hydrocracking of heavier hydrocarbon fractions to lower boiling products preferably utilizes bifunctional catalysts having a cracking and a hydrogenating function (U.S. Patent 3,304,254; U.S. Patent 3,634,345). While the hydrogenation function is known, e.g. of metals of the VIII * and / or YI * lifting group of the PSE or their oxides or sulfides is represented as cracking component for

K QQfiO

233455 3

the reaction proceeding by the carbonation mechanism, a Brönstedt-acidic material, such as amorphous or crystalline aluminosilicates of different SiO ₀ / Al ₀ CU ratio

C.C. J

and different cation occupancy. Particularly suitable cracking components have been found to be zeolites, which are used in particular when gasoline fuel components are a desired or exclusive target product of the hydrocracking process. The heavy gasoline fractions resulting from hydro-splitting are e.g. excellent Reformingeinsatzprodukte and often just because of a hydro-splitting process is realized.

Inevitably, a relatively strong attack of short-chain hydrocarbons down to methane occurs in hydro-sludge processes *

Conventional hydrosolating processes yield e.g. gaseous hydrocarbons in an amount of about 5 to 20% by weight, based on the raw material used, and a ratio of light gasoline (boiling point: initial boiling point to 373 K) to heavy gasoline (boiling point: 373 to 453 K) of about 1: 2 to 1: 1 , Process pressure, working temperature and raw material quality influence the absolute values, the first two parameters exceed the quality of the Leicht'oenzinanteils, so that often the light gasoline must be accepted as a forced attack with,

Object of the invention

The aim of the invention is a reduction of the seizure of low-boiling, including gaseous hydrocarbons in favor of such average Siedelage with otherwise constant degrees of conversion in hydrosolating heavy raw materials.

233455 3

Explanation of the essence of the invention

The invention has for its object to make the pore structure of zeolite-containing hydrocracking catalysts so that at least constant catalytic activity, the selectivity is shifted towards long-chain Bydrospaltprodukte.

According to the invention, this object was achieved by a process for preparing hydrocracking catalysts having a zeolite content of 40 to 80 and improved pore structure, wherein the activated catalyst has a maximum in the distribution of pore volumes for pores with pore radii> · 7.5 nm in the radius range 100 to 500 nm , preferably 100 to 300 nm, dissolved by subjecting the catalyst to extrusion by extrusion of a plastic slurry prepared using from 5 to 10 mass of SiO 2 in the form of a silica sol containing no alkalis, as 0.25 mass of alkali oxides the solid content corresponds, and da3 was adjusted before use by means of nitric or hydrochloric acid to a pH 7 / ert of 2 to 2.5, and also about 1 to 10 Hassel a Plastifizierungsmitteis such as oxyethyl cellulose, polyvinyl alcohol or polyvinyl acetate occurs.

The silica content introduced via the silica sol does not play any role in the catalysts on which the invention is based, while it has a drastic effect in WP 123,949, because in the case of X-ray amorphous aluminosilicates the acidity and thus the catalytic activity are influenced by the SiO 2 content In the catalyst according to the invention, the silica sol acts merely as a binder.

A special embodiment of the process according to the invention is that a silica sol of the above composition is used, which is adjusted to a pH of from 2 to 2.5 before addition to the catalyst powder with nitric or hydrochloric acid. The binding properties of the silica

233455 3

Sols without prior pH-Sinsteilung to values around 2 to 2.5 are unsatisfactory and give strength problems in the technical use of such catalysts-On the other hand, however, loses such a silica sol with pH 2 to 2.5 its plasticizing properties, so that the addition of a plasticizer in contrast to the WP 123 949 becomes mandatory.

It has been found that hydrocracked catalysts prepared in this way fulfill the object of the invention. They are characterized by the fact that they have maxima in the distribution of pore volumes for pores with pore radii> 7.5 nm in the radius range 100 to 500 ma, preferably 100 to 300 nm. It has also been found that such catalysts have a very excellent activity-time behavior and moreover allow high specific loads and that the desired effectiveness can be significantly increased if for the catalyst molding eia_ 'ratio of (geometric) surfaces to volume Die.9 is chosen * The preferred formation of such narrow pore areas is achieved by the influence of the invention in the deformation process. However, problems of the Pormling strength su are to be considered for the technical catalyst use, so that it is not possible to simply control the pore turnover via the pressure during the deformation.

embodiments

example 1

Catalyst A (comparative catalyst)

70 pigs of a hydrogel component of the type Pd Ii IJH ₁ Ia Y and 30% by weight of a hydrorefining component of the type Ii / V / 0., On amorphous aluminosilicate, each based on the anhydrous material, in powder form together with 3 mass% powder granite (ref. on the Sinsatzmischung) intimately

233455 3

mixed and then by means of pilling press au cylinder moldings with the dimensions 5 s 5 now deformed.

Catalyst B

It corresponds in composition and method of preparation to the catalyst A, but instead of powdered graphite, 3% Mg stearate was used as the Yerpillungshilfsmittel.

Example 2 Catalyst B

Hydrospalt and hydrorefining component of the same composition and in the same ratio as for the catalyst A were first dry-mixed in a Zweiwellenmiseher and then added as much silica sol (30 % SiO ₂ , EEL-stabilized) that a quantitative proportion of 5 masses of SiO ₂ based * on the Anhydrous catalyst mixture results. After thorough mixing, as much of a solution of oxyethylcellulose in water was added until, after vigorously kneading the mixture, a plastic mass was formed which was perfectly deformable by means of a screw extruder, which was then extruded into cylindrical strands with a diameter of 5 mm. The extruded moldings were air dried at 373 to 393K. _t

Example 3 Catalyst C

Catalyst C corresponds to the preparation and composition of the catalyst B only the silica sol was adjusted to a pH of 2 before addition by means of concentrated nitric acid.

Example 4 Catalyst D

Catalyst D corresponds in Pier position and composition of the catalyst B, only the plasticized mass was to

-233455 3

Strandformlingen with lens-shaped cross section estrudiert, which have a ratio of (geometric) surface to volume of 11.

Example 5 Catalyst E

40 leaves a hydrosoluble component of the type M UB ₇ , ITa Y and 60 leaves a hydrorefining component of the type Hi / MoO-, on amorphous aluminosilicate, in each case based on the anhydrous material were mixed as in Example 2 and then as much silica sol (6 % SiO, unstabilized ) is added so that a quantitative proportion of 7 masses SiOp ₅ based on the water-free catalyst mixture results. For plasticization, a 10% solution of polyvinyl alcohol in 7% was added and the plastic mass was extruded into strand moldings having a lenticular cross section, as indicated in Example 4. In contrast to example 4, however, the silica sol was adjusted to pH 2 just before the addition with concentrated nitric acid. >

Example 6 Catalyst P

80% by mass of a hydrocracking component according to Examples was mixed with 20% by weight of a hydrorefining component. according to Example 1 with the addition of 10 mass of SiO ₂ based on the free water-free catalyst mixture, in the form of a silica sol (30% SiO 2; NBU-stabilized) brought to pH 2.2 using concentrated nitric acid and a 10% aqueous solution of oxyethylcellulose Plasticization estrudiert to cylindrical strands of 5 mm diameter, which were dried at 373 to 393 K in air.

Example 7

In the following table, the pore distributions of the catalysts are compared before and after a thermal activation of 3 h at 653 K under flowing hydrogen:

-233455 3

Table 1

Catalyst: A B-D Ξ Ρ Activation: - without with no without with no without with

in cm / g

Pore radius-area

7.5-15 33m 0.029 0.021-0.019 0.016 0.020 0.018 0.013 0.015

15-30 "0.0-36 0.032 0.018 0.021 0.022 0.020 0.015 0.018

30-50 »0.018 0.022 0.017 0.01 $ 0.015 0.017 0.030 0.023

50-100 "0.091 0.140 0.041 0.042 0.0δ0 0.072 0.045 0.040

100-150 ^M 0.053 0.076 0.066 0.080 0.091 0.142 0.092 0.085

150-300 »0.005-0.163 0.219 0.145 0.170 0.181 0.241

300 - 500 "- - 0,002 - 0,002 0,002 0,010 0,031

500 - 1000 »- '- 0,001 0,002 - 0,002 0,003 0,007

1000 - 2500 »0.004 0.004 0.002 - 0.002 0.003

2500 - 7500 «------- 0,002

As can be clearly seen, the catalysts according to the invention show pore volume masses in the desired ranges, which, in contrast to the Tergleichs catalyst, are even more pronounced by thermal activation.

Table 2 compares the mechanical strengths of the catalysts, measured as abrasion resistance or abrasion in a rotating drum under defined conditions after prior thermal activation.

Table 2

Catalyst ABC D E P

Abrasion resistance 98.5 72.0 96.1 68.1 97.2 95.2 in mass%

Attrition in pig 1.5 25.3 3.5 27.0 2.5 3.7

233455 3

Table 2 indicates that the catalysts, whose silica sol content was used without adjusting the pH to 2 to 2.5, have insufficient strength values for a technical use »which, according to many years of experience, abrasion resistance of> i95 ingot and abrasion ^ .4 Mass% requires »

Example 8 '

The catalysts were tested under the following parameters:

Pressure: 200 at

Load: 3 v / vh

Gas: Product Ratio: 1000: 1

As the raw material, an unrefined DK cut (boiling range: 180 to 36O ⁰ G) was used and the reaction temperature adjusted so that a degree of conversion of about · 60% by weight, based on the raw material, was achieved

 The following table summarizes the results:

Table 3

Catalyst A B C D E F

Temperature in K 653 653 653 653 658 649 .Gasf. Kohlenwasserst. 18.3 12.3 13.0 9.1 8.6 12.0 in%

Initial boiling point - 373 K 20.2 19.0 18.3 15.3 Η, Ο 18, 'δ in mass%

373 - 453 K in 22.4 29.3 30.6 35.5 36.3 31.1

As can be seen from the table, the catalysts according to the invention give up to about 9 mass of higher liquid yields, wherein the ratio between light and heavy fuel can be shifted from about 1: 1 up to about 1: 2 in relation to the bulk weights listed below the specific load, expressed in g / g, h, changes with the following factor;

- ⁹ - 233455 3

A ' bulk weight factor catalyst B - 820 g / 1 1.0 η ~ 5βΟ g / 1 1.47

This results in significant economic benefits for the user, which are expressed in a corresponding reduction in catalyst at the same power.

Claims (2)

- ¹⁰ -233455 3 invention claim 1. A process for preparing hydrocracking catalysts with a zeolite content of 40 to 80 massed and improved! Pore structure, wherein the activated catalyst has a Maxim in the distribution of pore volumes for pores with pore radii:> · 7.5 mn in the radius range 100 to 500 mn, preferably 100 to 300 nm, characterized in that the shaping of the catalyst by extrusion of a plastic A composition prepared by using 5 to 10% by mass of SiO 2 in the form of a silica sol containing no more than 0.25% by weight of alkali oxides by weight of solids and which, prior to use by means of nitric or hydrochloric acid, is brought to pH Value of from 2 to 2.5, and in addition about 1 to 10% by weight of a plasticizer, such as oxyethyl cellulose, polyvinyl alcohol or polyvinyl acetate, takes place · 2. The method according to item 1, characterized in that catalyst moldings are prepared which have a ratio of (geometric) surface to volume of ΞΞΐ 9 *