CS205697B1 - Method of preparation of the catalyser for making the high-indexed oils by hydrogenation of the petroleum distillation fractions - Google Patents

Description

The invention relates to a process for the production of an improved catalyst for the process of simultaneous hydrogenation, selective cleavage and isomerization of petroleum fractions containing aromatic hydrocarbons, sulfur, nitrogen and oxygen compounds, to obtain a deep refined oil fraction suitable for producing high viscosity index lubricating oils.

Catalytic treatment of heavy petroleum fractions, including simultaneous hydrogenation, selective cleavage and isomerisation, is carried out to remove harmful or undesirable compounds, such as sulfur and nitrogen compounds, which impair the color and oxidation stability of oil and aromatic hydrocarbons that impair viscosity index and under certain conditions oxidation and color stability of products.

Oils with a high viscosity index have a higher content of less branched alkanes, contain low-condensed cyclanes with one or more long side chains and, in particular, virtually free of condensed aromatic hydrocarbons with short alkane chains. The aromatic component of the high index oils is represented essentially by single-ring long-chain aromatics having a content of not more than 10 to 15% by weight. The content of sulfur and nitrogen compounds is usually very low and is at most 0.01% by weight. sulfur and a maximum of 100 ppm nitrogen.

The conversion of a heavy petroleum fraction containing, for example, more than 75% aromatics and more than 2% sulfur to a high viscosity index fraction, i.e. with low viscosity-temperature dependence, requires profound changes in its composition. This change is the result of a series of reactions, in particular hydrogenation of aromatic hydrocarbons to cyclanes, selective cleavage of cyclanic rings to form isoalkanes, and isomerization of cyclanes and paraffins to liquid hydrocarbons at normal and reduced temperatures. The presence of simple long chain aromatics (alkylbenzenes) is to some extent desirable because they have a relatively high viscosity index, a higher viscosity compared to alkanes of the same molecular weight, and also improve the lubricity of the oil. On the other hand, the presence of aromatic hydrocarbons having two or more rings is undesirable because their viscosity is highly temperature-dependent, which is unfavorable.

Suitable catalysts for carrying out the set of desired reactions are, for example, combinations of oxides or metal sulfides VI. and VIII. groups on carriers with balanced acid properties. Such acidic carriers include systems based on a combination of Al ₂ O ₃ + Cl ₂ , Al ₂ O ₃ + F ^- , Al ₂ O ₃ + PO 4 ^{3 -} , Ca ² + silicates and, in particular, crystalline, microcrystalline or X-ray aluminosilicates with varying SiO ₂ : Al ₂ O ₃ . It is emphasized that, in contrast to the catalysts recommended and used for deliberate hydroenergy fission (hydrocracking205697 forging) into gases, gasoline and distillate fuels, where strongly acidic carriers are used, weak to medium acidity catalysts with a balanced hydroenergy and cleavage activity. It is known that, due to the insufficient cleavage and at the same time high hydrogenation function of the catalyst, a product with a high content of condensed cyclanes resulting from the saturation of aromatic hydrocarbons is obtained. On the contrary, the predominance of the fission properties of the catalyst over the hydrogenation leads to excessive cleavage of the saturated molecules, the cleavage of the side chains from the alkylaromates, increased formation of gases and light liquid hydrocarbons and the accumulation of condensed aromatics in heavy product fractions. The composition of the amorphous aluminosilicates, which form the basis of most of the catalysts for the process, depends on the type of raw material to be processed and the operating conditions of the process and varies in the weight ratio SiO ₂ : Al ₂ O ₃ = 100: 1 to 1: 100. : 1 to 1:50.

Common processes for the production of amorphous aluminosilicates include, for example, precipitation of alkali metal silicate solutions with aluminum salt solutions at certain dilution, temperature and pH conditions, co-precipitation of alkali metal silicate and aluminate solutions with dilute acids such as H ₂ SO ₄ , HCl, HNQ ₃ solutions of ammonium salts, gaseous carbon dioxide or sulfur dioxide, etc., or saturation of the alumohydrate with silica chloride vapor and other known methods.

All of these methods generally require additional purification of the resulting deep aluminosilicate present from undesired impurities, such as Na +, K +, SO ₄ ² -, SO 3 ^2-Cl, or combinations thereof. This purification operation is carried out either by washing with water or by ion exchange, and in some cases also by displacement in the gas phase, for example by removing Cl - with NH3 gas. The ion exchange, performed almost exclusively in the aqueous environment, requires the use of an excessive amount of water, depending on the desired degree of removal of the above impurities and the technological arrangement of the exchange. High water consumption represents a relatively large amount in production costs, the washing operation requires the installation of large-volume containers and equipment and results in long-term material retention in the production node. The wash waters contain the salts removed at very low concentrations, especially at the end of the operation, and their regeneration is not always economically advantageous and simple.

A process for producing a catalyst and a support for this catalyst, in which the peptized alumina hydrate containing no impurities and pollutants is contacted with the silica hydrosol under conditions allowing at least partial aluminosilicate formation, results in a catalyst with a very flat temperature-dependency curve it is caused by a low content of strongly acidic centers with an acid strength greater than> 85 to 92% H ₂ SO ₄ and a low dependence of total acidity on the SiO ₂ content. Such a catalyst is advantageous in that it has a reduced sensitivity to the effect of elevated working temperature when used in the process, especially in the field of sharp temperature conditions, which is advantageous in the processing of raw materials whose conversion is accompanied by a large enthalpy change. local overheating of the fixed bed catalyst.

A disadvantage of this process for the production of the support and the catalyst is that at least partially reacting the alumohydrate with a silicic acid hydrosol, optionally after addition of Group VI.A and VIII metal compounds. This results in a mass difficult to form on conventional screw extruders and, after annealing, a poorly porous support or catalyst, or disintegrates in the drying and annealing process. Difficult formability causes difficulties in the actual processing of the catalytic mass and the low porosity catalyst incurs the excessive cost of the active ingredients contained in the total catalyst volume required.

The novel process for the preparation of the catalyst according to the invention removes the above-mentioned disadvantages in the technological processing of the catalyst, while at the same time maintaining a favorable flat curve of temperature-dependent cleavage activity.

The process according to the invention consists in contacting alumina alumohydrate substantially free of pollutants and impurities with silica hydrogel and metal compounds. Groups VI.A and VIII. conditions. paste of consistency suitable for extrusion on screw extruders.

Process for the preparation of a catalyst for the production of high index oils by hydrogenation of petroleum distillation fractions or deasphalted bottoms, containing Group VI.A and VIII metal compounds. % and at most 0.1 wt. % of alkali metals or alkaline earth metals, calculated as Na ₂ O, on a porous support composed of 1.0 to 80 wt. % silica and up to 20.0 to 99.0 wt. Alumina and alkaline earth metals containing not more than 0,5% by weight, preferably not more than 0,1% by weight, on the content of Al ₂ O ₃ , expressed in molar conversion to Na ₂ O, by the action of acid and addition of Group VI.A and VIII metal compounds. to the resulting paste according to the invention consists in the fact that said aluminum hydroxide is treated with a silicic acid hydrogel containing alkali metals or alkaline earth metals not more than 0.1 ° / o by weight. on the contained SiO _2, expressed in mole per Na2O, prepared by coagulation of the silica sol with aqueous solutions of acids, bases or salts, at a concentration of 0.1 to 10% SiO ₂ .

The peptized aluminum hydroxide is formed by Al 2 O 3 modification of the boehmite, pseudobohmite, bayerite or nordstandite. As peptizing compound, salts of strong or weak acids of metal VI are added. and / or VIII. group selected from group ί

6, for example, an amount of 0.02 to 0.5, preferably 0.05 to 0.1 equivalents of contained anions per mole of acetates, formates, nitrates, chlorides and oxalates of nickel and cobalt. A1 ₂ O ₃ . The silica hydrogel is prepared by coagulating the silica sol with aqueous solutions of acids, bases or salts at a concentration of 0.1 to 10% on SiO ₂ . Metals of Group VI.A and VIII. are Ni, Co and Fe or mixtures thereof, or Mq, W and V or mixtures thereof, or a combination of metals of both groups, and the total content of their compounds is 5 to 30 P / o by weight, based on the finished catalyst; (Co + N1): (Mo + V) lies in the range 1:20 to 5: 1, preferably 1: 1 to 1: 3.

Aluminum hydrate as one of the starting components may be used either in the form of a dried powder or a so-called wet cake formed as a product after washing the precipitated suspension.

The silica hydrogel is prepared from. silicic acid sol containing 5-35% S1O2 Duke (preferably obtained by MS. Pat. 132,722), and commonly 0.01 to 0.1% Na ₂ O to SiO ₂ conversion. Hydrogel is prepared from the sol by its coagulation induced by strong electrolytes such as acids, bases or salts at concentrations of 0.01 to 10% calculated on SiO ₂ .

In order to allow a sufficiently mutual reaction between the aluminum hydrate and the silica hydrogel, it is necessary that at least part of the aluminum hydrate is converted to a soluble or peptized form. This operation is normally carried out by adding suitable acidic substances, such as HN0 _3j CH3COOH HCOOH, HOCH ₂ COOH, '(COOH) _2, aluminum salts or complexes of monohydric alcohols, polyhydric boric acid. It has now been found that the desired effect of peptization can be achieved by adding salts of active metals such as, for example, acetates, nitrates, oxalates and formates of nickel and cobalt. The amount of peptization temperature depends on the morphological structure of the alumohydrate. For alumohydrates of the bohemic, pseudobohmitic and nordstanditic structures, it is sufficient to carry out peptization at temperatures of 20 to 50 ° C. Preferably, the peptization of the alumohydrate and the reaction with the SiO ₂ hydrogel is carried out in an efficient kneading device, eg a spherical or other similar device.

The advantages of the process for the production of the catalyst according to the invention and the properties of the catalyst in the process for producing high-end oils are set forth in the following examples.

Example 1

To 2000 g of a hydrate of aluminous structure containing 65.75 wt. Al ₂ O ₃ and 0.02% Na ₂ O 902 g of silica hydrogel and 690 g of nickel nitrate are added to the kneader. 100 ml of H ₂ O are added after 10 min. After kneading at 56 ° C for 1 h, 450 g of ammonium molybdate with 0.5% CH ₃ COOH are added. After a short kneading, the paste is extruded at 4 MPa through a 4 mm diameter die. The total kneading time was 2 h. After annealing, the catalyst contains 15% MoO ₃ , 8% NiO, 15% SiO ₂ , has a cutting edge strength of 24 N and a particle strength of 67 N, a water absorption of 32% ₎ bulk density of 660 g / l. The catalyst was designated A.

Example 2.

000 g of aluminum hydroxide of the bbhmitic structure with a grain size below 0.2 mm with an Al ₂ O ₃ content of 69.8 wt. and Na ₂ O 0.02 wt. was mixed in a 50 L mixer with 7000 g H ₂ O and 300 g glacial acetic acid. 8750 g of silica acid containing 30% SiO ₂ and 0.008% Na ₂ O are added in portions to the paste under kneading. After 4 hours of kneading, 3500 g of crystalline are added to the paste. Ni (NO _{3) second} 6 H ₂ O and knead - another 1 hour. After the addition of 3370 g of ammonium molybdate to the paste, an additional 2000 g of water are added. The total time of kneading the paste is 6 hours, then the material is extruded on the extruder. After ignition, the catalyst has a composition of 13.12 wt. % SiO ₂ , 4.90 wt. NiO, 17.35% wt. MoO ₃ , 0.06 wt. Na ₂ O, the rest is Al ₂ O ₃ . Its cutting edge strength is 10 Ň, particle strength 38 N, water absorption 25%, bulk density 930 g / l. The catalyst was labeled B.

Example 3

To 200 g of a Bayerite aluminum hydrate containing 65.7 wt. % Al ₂ O ₃ and 0.02 wt. Na ₂ O in a kneader with 90 g of a silica hydrogel containing 30% of SiO ₂ and 0.008 why. Na2O and 4 g glacial acetic acid. After 4 hours of kneading, the paste formed is extruded into extrudates with a diameter of 4 mm on an extruder. After drying at 120 ° C and annealing at 500 ° C, the extrudates are saturated with an ammonia solution of ammonium molybdate and nickel nitrate to a concentration such that the annealing catalyst at 500 ° C has a composition of 15% SiO ₂ , 8% by weight. NiO, 15 why. wt. MoO ₃ , 0.06 wt. Na ₂ O, the rest is Al ₂ O ₃ . The cutting strength is 22 N, the particle strength is 58 N, the water absorption is 34%, and the bulk density is 630 g / l. The catalyst was designated C.

Example 4

Catalysts A, B, C and a nickel-tungsten commercial catalyst used in the processing of vacuum distillates to feedstock for the preparation of lubricating oils were tested in flow reactors with a catalyst volume of 200 cm ³ . The catalysts are tested for a grain size of 1 to 2 mm under a hydrogen pressure of 15 MPa and a feed rate of 0.5 kg / h over a temperature range of 390 to 420 ° C. The ratio of hydrogen to feedstock is 1000: 1. The catalysts are activated and sulphurized with a mixture of hydrogen and hydrogen sulphide prior to the experiment.

A medium vacuum des-

Romaskin-type oil spillage: Density / 20 ° C 933 kg / m ³ Freezing temperature + 42 ° C Viscosity at 100 ° C 12.8 mm ² / sec Sulfur content 2.18 wt. Distillation range (5. to 90% vol.) 420-550 ° C Viscosity index after laboratory dewaxing to a freezing point of -12 ° C 39 Content of aromatically bound carbon Ca 20.1 wt.

The hydrogenated product is distilled off under reduced pressure. A distillation range of 370 to 390 ° C and a residue above 390 ° C. The residue was dewaxed with a 40:30:30 acetone: benzene: toluene mixture and the dewaxed oil was evaluated. The results of the analyzes for oils having a viscosity index of 105 and 120 are shown in the table.

Catalysts A, B and C, the preparation of which is given in Examples 1, 2 and 3, have better activity and selectivity than the commercial nickel-tungsten catalyst used for this process. Catalysts A and C prepared according to the invention have better properties than Catalyst B prepared according to Example 2 and allow the preparation of lubricating oils with high viscosity index at lower temperature and higher yield while maintaining a good degree of aromatic hydrocarbon refining.

Catalyst AND (B) .0 . Commercial nickel-tungsten catalyst 1 2 3 4 5 ⁸ 7 8 Yield of unparaffinized. % residual above 390 ° C after distillation of light fractions from the off-stream (flash point above 220 ° g) by weight. 67 58 64 52 66 57. 60 43 Dewaxed oil properties (freezing point —12 ° C): - Viscosity index 105 120 105 120 105 120 105 120 Viscosity 100 ° C mm2 / s θ, 5 5.5 6.6Ů 5.40. 6.5 5.5 5,57 4.52 Basic nitrogen content mg / l 0 0 2 0 0 0 0 0 Content of aromatically bound carbon Ca (n-d-M). % 7,5 ' 7.0 7.5 6.0 7.3 6.9 6.2 8.0 Content of triaromates - ultraviolet spectroscopy 1.50 1.70 1.45 1.65 .1,45 1.70 1.83 2.27 Temperature necessary to reach VI (activity) Noc: 2 ° C 400 415 408 418. 401 415 417 422

SUBJECT

Claims (1)

Process for the preparation of a catalyst for the production of high index oils by hydrogenation of petroleum distillation fractions or deasphalted bottoms, containing Group VI.A and VIII metal compounds. and at most 0.1% w / w. % of alkali metals and / or alkaline earth metals, calculated as sodium oxide, on a porous support comprised of 1.0 to 80 wt. % silica and from 20.0 to 99.0 wt. of peptized aluminum hydroxide with an alkali metal and alkaline earth metal content of not more than 0.5% by weight, preferably not more than 0.1% by weight, for the contained aluminum oxide, OF THE INVENTION correlated morally to sodium oxide by the action of silicic acid and addition of Group VI.A and VIII metal compounds. into a paste thus formed, characterized in that said aluminum hydroxide is treated with an acid hydrogel. Silicas with an alkali or alkaline earth metal content not exceeding 0,1% by weight to the silicon dioxide contained, expressed morally on sodium oxide prepared by coagulation of the silica sol with aqueous solutions of acids, bases or salts at a concentration of 0.1 to 10% of silica.