CS211488B1 - Catalyst for the Hydration Demetallization of Heavy Petroleum Distillates and / or Petroleum Distillation Residues and its Production Method - Google Patents

Abstract

The invention relates to a catalyst for the hydrodemetallization of heavy petroleum distillates or/and residual petroleum oils containing heavy metals and asphaltenes and a method for its preparation. A bentonite-based catalyst with a total pore volume of over 20.10 ml/g and a specific surface area of over 50 m^/g, formed into tablets or extrudates, is prepared either by tableting finely ground bentonite with a grain size of less than 0.2 mm and subsequent heat treatment up to 900 °C (from 250 °C), or is shaped after the addition of 10 to 70% water and 2 to 20% by weight ammonium carbonate (NH^)oCOj and peptization by the addition of 1 to 10% acid and heat treatment at the same temperatures.

Description

The present invention relates to a catalyst for the hydrodemetallization of heavy petroleum distillates and residual petroleum oils prepared on the basis of natural bentonite.

It is known that catalytic hydrogenation treatment of petroleum distillation residues results in significantly faster catalyst deactivation compared to similar distillate processing processes. In addition to coke-forming substances, catalyst deactivation is mainly caused by trace metals such as V, Ni, Fe, Ca and Na, which are contained in the raw materials and are concentrated in the heaviest fractions of petroleum residues - in their non-distillable asphaltene fraction. Once the accumulation of trace metals on the catalyst reaches a certain level, there is a permanent and profound loss of activity and the catalyst must be replaced with a fresh one. Therefore, heavy raw materials are often processed in two stages, where part of the organometallic compounds and asphaltenes are removed in the first stage. From it. Patent No. 1,770,996 and US Patent No. 3,180,820 describe two-stage catalytic hydrogenation of petroleum residues, where in the first stage a catalyst based on Al ₂ 0 ₃ -Si0 ₂ is used, on which asphaltenes and metalloorganic compounds of trace metals are converted. A demetallization contact based on manganese modules mined from the seabed is the subject of German Patent No. 2,235,954. Demetallization contacts based on bauxite are described - British Patent No. 736,382, natural clays - German Patent No. 2,421,478, wide-pored Al ₂ O ₃ - British Patent No. 1,438,645, or silica - German Patent No. 2,447,303.

The disadvantage of the above-mentioned processes is the relatively high price of the demetallization catalyst and the fact that demetallization is only partial. The aim of efforts in this field is to find a cheap demetallization contact that would operate with acceptable activity, have sufficient service life at a low degree of hydrocracking of the feedstock and low hydrogen consumption.

It has now been found that, of a number of natural materials tested as demetallization contacts, bentonite has proven to be the most advantageous from these points of view.

Bentonites are natural clayey soils, the main substance of which is the mineral montmorillonite. Montmorillonite is a hydrosilicate with a layered structure, high sorption capacity and large specific surface area. The dimensions of montmorillonite crystals are very small, they have not been measured by a direct method, and therefore there are several derived models of its structure. The Si:Al ratio for individual types of montmorillonites can vary from 2:2 to 6:2. For example, the following crystallochemical formula was determined by calculation for montmorillonite from the Braňany deposit:

^(Si 7.10 ^Al 0.90 ) ^IV (Alj^QFe, ₍₂₆ Mg ₀₍₃₂ ) ^V ^ ^Ca 0.48^®20^ ^OH \

The difference between individual types of bentonites is determined not only by the content of montmorillonite, but also by the content and type of other accompanying substances. The most common are Ca-bentonite, Mg-bentonite, Na-bentonite, with the substituted ion having a significant influence on the properties of bentonite. The chemical composition of bentonite affects the activity and selectivity of the catalyst. However, its applicability for the preparation of the contact does not change.

By simple processing and modification of the porous structure according to the invention, it was possible to prepare a suitable contact with good demetallization properties from bentonite.

The catalyst for hydrodemetallization of heavy petroleum distillates or/and residual petroleum oils, which are characterized by a content of heavy metals, especially vanadium V and nickel Ni above 100 ppm and asphaltenes above 3.0 wt. %, or other similar raw materials, is, according to the invention, formed of activated bentonite with a total pore volume above 0.10 ml/g, preferably 0.20 ml/gas, a specific surface area above 50 m ² /g, preferably 100 m ² /g, formed into the shape of tablets, hollow or solid extrudates with an outer diameter of 1 to 10 mm, preferably 2 to 5 mm.

The catalyst for the hydrodemetallization of heavy petroleum distillates and/or residual petroleum oils is produced by either finely ground natural bentonite, granulating under

0.2 mm, with the addition of 10 to 70% by weight of water, preferably 30 to 50% by weight of water and 0 to 20% by weight, preferably 5 to 12% by weight of ammonium carbonate (NH^) ₂ COj, peptized with nitric acid or another mineral or other organic acid, which is completely decomposed during the thermal treatment of the catalyst, in an amount of 1 to 10%, preferably 2 to 5% and shaped, or that finely ground natural bentonite, grain size below 0.2 mm, is mixed with graphite - usually with 2% - or stearine and shaped into tablets, after which the shaped particles are heat-treated at a temperature of 250 to 900 °C, preferably 400 to 600 °C, in the presence of air for 2 to 10 hours, preferably 3 to 6 hours.

The use of the contact prepared in this way is illustrated by the following examples. Bentonite from the Braňany deposit was used, which had the following composition:

SiO ₂ 41.0% by weight ai ₂ ° ₃ 17.0% by weight TiO ₂ 5.3% by weight ^Fe 2°3 18.5% by weight At ₂ 0 0.07% by weight MgO 2.5% by weight CaO 1.6% by weight to ₂ o 0.2% by weight

Example 1- comparative

Finely ground bentonite (grain size below 0.2 mm) was mixed with 2% graphite, which is added during tableting to increase binding, and shaped into tablets measuring 8x8 mm. The tableted material was heat-treated in the presence of air as follows:

Over a period of 2 hours, a temperature of 400 °C was gradually reached, followed by a 30-minute hold, over a further 75 minutes the temperature was increased to 800 °C and from that point on the temperature was increased over a period of 55 minutes to 950 °C. The loss on annealing at 950 °C was 19.5%. The contact obtained, designated A, had the following properties:

bulk density g/l 1,012 specific surface area m ² /g 25.8 pore volume ml/g 0.15 mesopore volume ml/g 0.09 macropore volume ml/g 0.05 mean pore radius nm 1.26

The catalyst therefore does not meet the definition of the subject matter of the invention and is presented for comparison to illustrate the influence of the porous structure of the catalyst on its activity and selectivity. The annealing temperature of 950 °C was chosen because it changes the crystallographic structure of bentonite.

Contact A was subjected to a hydrodemetallization test of 45% distillation residue from atmospheric distillation of crude oil with a content of 3.2% by weight of asphaltenes in a grain size of 2 to 3 mm. The test results are summarized in Table 1.

Table 1

Reaction temperature °C Raw material 370 395 420 LHSV Volumetric Flow Rate 0.5 0.5 0.5 Product properties hydrog. specific gravity 0.959 0.943 0.936 0.926 sulfur content % wt. 2.43 2.40 2.22 2.06 degree of desulfurization % - 1.2 8.6 15.3 Konradson's carb. number % wt. 8.3 7.9 8.1 6.4 asphaltene content ³ “ ¹ ·) % by weight. 3.2 Trace metal content ppm: from above 101.3 73.2 58.0 38.5 nickel 33.3 27.6 23.0 17.1 iron 16,} 7.8 7.0 6.3 sodium 12.6 3.3 1.3 1.6 vanadium degradation % - 28.8 43.7 62.0 nickel removal % - 27.2 31.0 48.6 HDS ^X ) HDMe - 0.05 0.219 0.261

^x ) The ratio of the degree of desulfurization/degree of vanadium + nickel degradation characterizes the demetallization activity of the catalyst. HDMe is calculated as ^(V . ^{+ (Ni} e - ^Hi o>

» p ⁸ p . ioo ^V . ^{+ Ki} si") determined using n-heptane

Example 2

Contact B was prepared by the same procedure as contact A, with the difference that the heat treatment of contact B was carried out at a temperature of 500 °C. Heating to the specified temperature was carried out for 2 hours, the delay after reaching the temperature was 4 hours. The obtained contact according to the invention, designated B, had the following properties:

bulk density g/1 980 specific surface area m^/g 56.8 pore volume ml/g 0.18 mesopore volume ml/g 0.13 macropore volume ml/g 0.04 mean pore radius nm 1.58

The annealed contact was used for hydrogenation demetallization tests in the form of fragments of 2 to 3 mm in size. The test results are contained in Table 2. The same raw material was used.

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Table 2

Reaction temperature °C 370 395 420 LHSV Volumetric Flow Rate . 0.5 0.5 Product properties hydrogen.: ' m. mass at 20 °C 0.943 0.940 0.916 sulfur content % wt. 2.28 2.11 1.81 degree of desulfurization % 6.2 '13.2 25.6 Konradson carb. number % wt. 73 6.8 5.1 Trace metals ppm: •5 from above 64.1 52, U ‘' 20.4 nickel 23.7 22.2 _? >13 iron 6.6 7.3 > In 8.5 sodium 1.2 1.1. , ·. 4.2 vanadium degradation % 36.7 48.6 79.9 nickel removal % 28.8 33 .3 66.1 HDS HDMe 0.178 0.295 0.335

Example 3 Finely ground bentonite (grain size below 0.2 mm) was • mixed with a stainless steel kneading machine with 10% (NiLJgCO, and with 2% (30%) HNOj with the addition of 50% wt. water. After one hour of kneading- then the mixture was shaped into extrudates with a diameter of 2 mm. Extruded contact (C) was sentenced 5 hours at 120 °C and annealed in the presence of air at 500 °C 2 +~4 hrs. The contact obtained according to the invention, designated C, had the following features: bulk weight g/1 800 specific surface area m^/g 117.1 pore volume ml/g 0.23 mesopore volume ml/g 0.22 macropore volume ml/g - mean pore radius nm 1.99 The results of testing the demetallization activity of contact C are contained in table 3. Raw material as in example 1. Table 3 Reaction temperature °C 370 395 420 LHSV 0.5 0.5 0.5 Product features hydrog.: m. weight h ² ® 0.942 . . 0.934 0.910 sulfur content % wt. 2.17 . 2.01 1.46 degree of desulfurization % 10.7 17.3 39.9 Konradson carbon, mass % 6.9 5.2 . 4.8 viscosity cSt/100 °C - 19.8 . ¢,6

continuation of table 3

Reaction temperature °C 370 395 420 LHSV Volumetric Flow Rate 0.5 0.5 0.5 Trace metals ppm: from above 67.4 51.4 . 20.8 nickel 29.2 21.9 11 .3 iron 8.8 12.1 8.2 sodium 0.5 0.4. 1.6 vanadium degradation rate % 33.5 49.3 79.5 nickel degradation rate 56 12.3 34.2 66.1 KDS HDMe 0.379 0.380 0.524

The results of testing contacts B, C in comparison with contact A in the hydrogenation demetallization of fuel oil with gas show that these contacts are characterized by a relatively high demetallization selectivity. With increasing hydrogenation temperature, the degree of trace metal degradation increases rapidly. The demetallization activity of bentonite-based contacts depends on the textural properties that can be influenced in the process of preparing these contacts. This follows from a comparison of the textural properties of contacts A, B and C given in Table 4. Table 4 Contact designation A B C Addition (NH^^CO^ 0 0. 10 Annealing temperature °C 950 500 500 bulk weight g/1 1,012 980 800 specific surface area m ² /g 25.8 56.8 117.1 pore volume ml/g 0.15 0.18 0.23 degree of demetallization HDMe ^x ) 56 58.7 76.4 76.2 HDS desulfurization degree ^X ) 56 15.3 25.4 39.2 HDS/HDMe ^x ) 0.261 0.335 0.52.

^x ) determined at a temperature of 420 °C and LHSV = 0.5 h"'

The results shown in Table 4 show that by special treatment of bentonite, compared to simple tableting, the specific surface area and pore volume can be significantly increased, and thus the hydrodemetallization and hydrodesulfurization (HDS/HDMe) activity in the treatment of petroleum residues can be significantly increased. Furthermore, the selectivity of the catalyst can also be changed.

The catalyst lifetime is determined by the content of heavy metals and asphaltenes in the processed raw material. The catalyst consumption also depends on the reaction conditions and ranges from 0.2 to 0.5 kg of de-aetalization catalyst per t of input raw material.

Claims (3)

SUBJECT OF THE INVENTION 1. Catalyst for the hydrotreating of heavy petroleum distillates or residual petroleum oils containing heavy metals, in particular vanadium V, nickel N1 over 100 ppm and asphaltenes over 3.0% by weight, or other similar raw materials, characterized in that: formed of activated bentonite with a total pore volume of above 0.10 ml / g, preferably above 0.20 ml / g and a specific surface area of over 50 m 2 / g, preferably over 100 m 2 / g, formed into tablets, hollow or solid extrudates with an outside diameter of 1 to 10 mm, preferably 2 to 5 mm. 2. A process according to claim 1, wherein the finely ground natural bentonite has a grain size below 0.2 mm < b > % water, preferably 30 to 50 wt. water and 2 to 20 wt.%, preferably 5 to 12 wt. ammonium carbonate (NH4 / gCO3) is peptized with nitric acid or other mineral or organic acid in an amount of 1 to 10%, preferably 2 to 5% and shaped, after which the shaped particles are heat treated at a temperature of 250 to 900 ° C, preferably 400 to 600 ° C, in the presence of air for 2 to 10 hours, preferably 3 to 6 hours. 3. A process for the preparation of the catalyst according to claim 1, wherein the finely ground natural bentonite particle size below 0.2 mm with the addition of graphite or atearin is tabletted and heat-treated, characterized in that the heat treatment is carried out at 250-900 [deg.] C. 600 ° C, in the presence of air for 2 to 10 hours, preferably 3 to 6 hours.