KR20000029529A - Catalyst, use thereof and preparation process - Google Patents

Abstract

PURPOSE: A method is provided to represent the hydroconversion of good aromatic compounds, for a catalyst which represent excellent hydroconversion for mono aromatic compounds. CONSTITUTION: Catalyst comprising from 0.1 to 15 % by weight of a noble metal selected from one or more of platinum, palladium and iridium, and from 2 to 40 % by weight of manganese and/or rhenium supported on an acidic carrier, said weight percentages indicating the amount of metal based on the total weight of carrier. Use of this catalyst in a process wherein a hydrocarbon feedstock comprising aromatic compounds is contacted with the catalyst at elevated temperature and pressure in the presence of hydrogen. Process for the preparation of the above catalyst, which process comprises incorporating the catalytically active metals into the carrier followed by drying and calcining.

Description

Catalyst, its use and preparation method {CATALYST, USE THEREOF AND PREPARATION PROCESS}

The present invention relates to catalyst compositions and to their use in hydroconversion processes wherein hydrocarbon oils comprising aromatic compounds are contacted with hydrogen in the presence of such catalyst compositions.

Hydrotreating catalysts are known in the art. Conventional hydrotreating catalysts comprise one or more Group VIII metal components and / or one or more Group VIB metal components supported on a refractory oxide support. The Group VIII metal component may be a non-noble metal substrate such as nickel (Ni) and / or cobalt (Co), or a precious metal substrate such as platinum (Pt) and / or palladium (Pd). Useful Group VIB metal components include those based on molybdenum (Mo) and tungsten (W). The most commonly applied refractory oxide support materials are inorganic oxides such as silica, alumina and silica-alumina and aluminosilicates such as modified zeolite Y. Specific examples of conventional hydrotreating catalysts are NiMo / alumina, CoMo / alumina, NiW / silica-alumina, Pt / silica-alumina, PtPd / silica-alumina, Pt / modified zeolite Y and PtPd / modified zeolite Y.

Hydrotreating catalysts are commonly used in processes in which a hydrocarbon oil feed is contacted with hydrogen to reduce its aromatic, sulfur and / or nitrogen compound content. Generally, hydrotreating methods for which aromatic compound content reduction is the main purpose are referred to as hydrogenation methods, and methods mainly focused on sulfur and / or nitrogen content reduction are referred to as hydrodesulfurization and hydrodenitrification, respectively. Current environmental standards require very low aromatic and sulfur and nitrogen contents of oil products, and it is expected that the standards for aromatics, sulfur and nitrogen will be more stringent in the future. Therefore, in the purification of hydrocarbon oil fraction, thorough hydrogenation, thorough hydrodesulfurization and thorough hydrodenitrogenation capability will become increasingly important.

Effective hydrogenation of monoaromatic compounds is usually difficult to achieve with conventional hydroprocessing catalysts. On the other hand, dedicated aromatic compound hydrogenation catalysts usually have relatively low sulfur and / or nitrogen tolerance and thus exhibit poor hydrogenation activity in the presence of significant amounts of sulfur- and / or nitrogen-containing compounds. For this reason, conventional methods for reducing the amount of aromatic compounds and sulfur- and nitrogen-containing compounds include aromatic compounds still remaining after the first stage of hydrodesulfurization and / or hydrodenitrification and the removal of ammonia and hydrogen sulfide which are usually formed. Is a two-step method with a second step for hydrogenation.

The present invention aims to provide a hydroprocessing catalyst which exhibits excellent aromatic compound hydrogenation activity and at the same time has good hydrodesulfurization and / or hydrodenitrification activity. This means, therefore, that the catalyst composition must be able to effectively promote the hydrogenation of aromatic compounds in the presence of significant amounts of sulfur- and nitrogen-containing compounds. The present invention also aims to provide a hydrotreating catalyst that exhibits excellent hydrogenation activity for monoaromatic compounds. It is understood that the use of such catalysts in hydrotreating processes will increase the likelihood of meeting future low-content criteria for (mono) aromatic compounds, sulfur and nitrogen.

Accordingly, a first aspect of the invention relates to a catalyst composition comprising from 0.1 to 15% by weight of a noble metal selected from at least one of platinum, palladium and iridium, and from 2 to 40% by weight of manganese and / or rhenium, supported on an acidic carrier. (The weight percentage indicates the amount of metal based on the total weight of the carrier).

Manganese and rhenium are both members of the VIIB group of the Periodic Table of Elements. Technetium, a Group VIIB third metal, is not useful because of its instability, as will be appreciated by those skilled in the art. On the one hand, the catalytically active metal, ie platinum and / or palladium and / or iridium, and on the other hand, manganese and / or rhenium may be present in elemental form, as an oxide, as a sulfide or as a mixture of two or more of these forms. . As discussed in detail below, suitable preparations for use in preparing the present catalysts include a final step of firing in air, which at least partially converts the catalytically active metal to its oxide. Typically this final firing step converts substantially all catalytically active metals to their oxides. When the catalyst is then contacted with a sulfur-containing feed, some or all of these oxides are sulfided and converted to the corresponding sulfides (“in situ” sulfids). Very good catalytic performance is observed in this situation, so it is considered a preferred embodiment of the present invention to have all or part of the catalytically active metal present as sulfides in the catalyst. Thus, the catalyst can also be subjected to individual presulfurization prior to contacting the feed. The sulfidation degree of the metal oxide is adjustable by temperature and related parameters such as partial pressures of hydrogen, hydrogen sulfide, water and / or oxygen. The metal oxide is fully convertible to the corresponding sulfide, but suitably an equilibrium is formed between the oxide and sulfide of the catalytically active metal such that the catalytically active metal is present both as oxides and sulfides.

As described in more detail below, the catalyst according to the invention can suitably be used in various hydroconversion processes. The catalyst is particularly useful for the hydrogenation of gas oils, thermally and / or catalytically decomposed distillates (such as light cycle oils and cracked cycle oils) and mixtures of two or more thereof. It turns out useful. These oils usually contain relatively large amounts of aromatic compounds, sulfur-containing compounds and nitrogen-containing compounds. The amount of such compounds should usually be reduced in terms of environmental regulations. Aromatic compound reduction may also be desirable to reach certain technical quality conditions such as cetane number for automotive diesel, smoke point for jet fuel and color and stability for lubricating oil fraction. When the catalyst according to the invention is used for the hydrotreating of diesel, thermally and / or catalytically decomposed distillates and mixtures of two or more of them, for example, the reduction required to meet automotive diesel conditions can be achieved in a single step. have. The catalyst of the present invention is particularly effective for reducing the amount of mono-aromatic compounds in the final product, even in the presence of significant amounts of sulfur- and nitrogen-containing compounds.

The catalyst according to the invention comprises from 0.1 to 15% by weight of platinum and / or palladium and / or iridium and from 2 to 40% by weight of manganese and / or rhenium as catalytically active materials. If a smaller amount of catalytically active material is applied, the catalytic activity is so low that it is not commercially valuable. On the other hand, if the amount of catalytically active material is greater than the indicated upper limit, further increase in catalytic activity does not guarantee extra metal mass cost. This applies in particular to platinum and palladium. Good results can be obtained with catalysts comprising noble metals, ie 3 to 10% by weight of platinum and / or palladium and / or iridium and 2 to 2, preferably 5 to 30% by weight of manganese and / or rhenium.

In the precious metal component, it is preferable to use only palladium, and among manganese and rhenium, rhenium is the preferred metal. Thus, very preferred catalysts are catalysts comprising palladium and rhenium as catalytically active metals.

The carrier used to support the catalytically active substance is an acidic carrier. Acidic carriers are known in the art. Examples of suitable carriers for the present invention include aluminosilicates or silicoaluminophosphate zeolites, amorphous silica-aluminas, aluminas, fluorinated aluminas, phyllosilicates or mixtures of two or more thereof. Acidic carriers. The type of acidic carrier used depends largely on the application of the catalyst. In most applications, however, it is preferred that the carrier comprises a zeolite. Examples of suitable zeolites are silicoaluminophosphates, such as SAPO-11, SAPO-31 and SAPO-41, and ferrierite, ZSM-5, ZSM-23, SSZ-32, mordenite, beta zeolite and pauzasite aluminosilicate zeolites, such as (faujasite) type zeolites such as faujasite and synthetic zeolite Y. The use of silicoaluminophosphate may be considered when using the catalyst in lubricating base oil production processes, including, for example, hydroconversion steps. In general, however, the use of aluminosilicate zeolites is preferred. A particularly preferred aluminosilicate zeolite is zeolite Y, which is usually used in modified form, ie dealuminated form. Especially when the catalyst according to the invention is used as a hydrotreating catalyst for reducing the content of aromatic compounds and sulfur- and nitrogen-containing compounds, the use of an acidic carrier comprising modified zeolite Y is very preferred. Particularly useful modified zeolite Y has a unit cell size of less than 24.60 mm 3, preferably 24.20 to 24.45 mm ₃ , more preferably 24.20 to 24.35 mm 3, and a SiO ₂ / Al ₂ O ₃ molar ratio of 5 or 10 to 150, such as 5, 10 Or 15 to 110, or 5, 10, 15 or 30 to 90. Such carriers are known in the art, for example EP-A-0,247,678; EP-A-0,303,332 and EP-A-0,512,652. Alkali metals-usually sodium-modified zeolites of increased content, such as those based on EP-A-0,519,573, can also be suitably applied.

In addition to any of the carrier materials described above, the carrier may also include a binder material. The use of binders in catalyst carriers is known in the art and suitable binders include inorganic oxides and clays such as silica, alumina, silica-alumina, boria, zirconia and titania. Among them, it is preferable to use silica and / or alumina for the purpose of the present invention. If present, the binder content of the carrier may vary from 5 to 95 weight percent based on the total weight of the carrier. In a preferred embodiment, the carrier comprises 10 to 60% by weight binder. A binder content of 10 to 40% by weight appears to be particularly advantageous.

The catalyst according to the invention can be used in various hydrogenation processes in which a hydrocarbon feed comprising an aromatic compound is contacted with the catalyst at high temperature and high pressure in the presence of hydrogen. Embodiments of this method are hydrocracking, lubricating oil production (hydrocracking / hydroisomerization) and hydroprocessing.

Accordingly, the present invention also relates to the use of the catalysts described above in a process in which a hydrocarbon feed comprising an aromatic compound is contacted with the catalyst at high temperature and high pressure in the presence of hydrogen. Since the catalyst is active not only in the aromatic compound hydrogenation but also in the removal of sulfur and / or nitrogen compounds, hydrocarbon feeds comprising sulfur and / or nitrogen containing compounds in addition to aromatic compounds are particularly suitable.

The catalyst according to the invention is particularly useful as the first stage catalyst in the two stage hydrocracking process because of its excellent hydrotreatment performance. Thereafter, the second stage catalyst is a dedicated hydrocracking catalyst.

Removal of sulfur and / or nitrogen containing contaminants from the feed; And / or hydrogenation of aromatic compounds; And / or hydroisomerize linear and slightly branched hydrocarbons into further branched hydrocarbons; And / or one or more hydroconversion steps may be included in the lubrication base oil production process to hydrocrack waxy molecules (usually long chain paraffinic molecules or molecules containing ends of this type) into smaller molecules. In application to such a lubricating base oil production method, the catalyst according to the invention preferably comprises a carrier comprising amorphous silica-alumina, fluorinated alumina or zeolite with silica and / or alumina as binder. If the purpose of the hydrotreating reaction is mainly to occur, it is preferable to use a carrier containing modified zeolite Y. If the main purpose is to decompose and / or hydroisomerize the waxy molecule, it may comprise fluorinated alumina, amorphous silica-alumina or zeolites such as ferrierite, ZSM-5, ZSM-23, SSZ-32 and SAPO-11. Carriers are preferred. The hydroconversion step in the process for preparing a lubricating base oil typically comprises contacting the lubricating oil feed with a suitable catalyst in the presence of hydrogen at a temperature of 200 to 450 ° C. and up to 200 bar of pressure. Examples of lubricating base oil production processes in which the catalyst according to the invention can be used are disclosed in GB-A-1,546,504 and EP-A-0,178,710.

The catalyst according to the invention appears to be particularly suitable for use in hydrotreating processes. Suitable hydrotreatment operating conditions are temperatures 200 to 450 ° C., preferably 210 to 350 or 400 ° C., and total pressures 10 to 200 bar, preferably 25 to 100 bar. Examples of suitable hydroprocessing methods are described in EP 0,553,920 and 0,611,816. Suitable feeds for this hydroprocessing process include catalytically cracked gasoline, diesel, light diesel, thermal and / or catalytically cracked distillates (such as light cycle oils and cracked cycle oils) and two or more of them. Mixture. Many of these feeds typically comprise at least 70% by weight hydrocarbons having a boiling point of 150 to 450 ° C. When used in such hydrotreating catalysts, it is preferred that the carrier comprises the above indicated binder. For hydrotreating the preferred acidic material in the carrier is aluminosilicate zeolite, most preferably modified zeolite Y. The catalysts show good hydroprocessing activity and appear to be particularly effective for the hydrogenation of mono-aromatic compounds, even in the presence of significant amounts of sulfur- and nitrogen-containing compounds. The catalyst is also very effective in the hydrogenation of di-aromatic and higher aromatic (tri + aromatic) compounds.

The invention also relates to the process for preparing a catalyst as described above comprising incorporating a catalytically active metal into a refractory oxide carrier, suitably using impregnation or ion exchange techniques, followed by drying and calcining and optionally presulfurization. . In order to obtain a catalyst with particularly good catalytic activity, this process can be carried out by the following steps:

(a) impregnating the carrier with one or more solutions containing noble metal compounds selected from compounds of platinum, palladium and iridium, and one or more solutions containing manganese and / or rhenium compounds, optionally with intermediate drying and / or calcining ;

(b) drying and calcining the carrier thus impregnated at a temperature of 250 to 650 ° C.

A preferred method of impregnation of the carrier is so-called pore volume impregnation, which involves treating the carrier with a specific volume of impregnation solution, wherein the impregnation volume is substantially equal to the pore volume of the carrier. In this way, the complete impregnation solution is used up. Since the resulting catalyst shows particularly good performance, this impregnation method appears to be particularly suitable for the present invention. The impregnation step (a) is carried out using one impregnation solution containing all metal components or with two separate impregnation steps (one step impregnated with platinum and / or palladium and / or iridium and with manganese and / or rhenium). One step of impregnation), possibly with an intermediate drying and / or firing step.

Metallic components usable in the impregnation solution for preparing the catalyst according to the present invention are known in the art. Common manganese compounds are water soluble salts thereof, such as manganese sulfate, manganese nitrate and manganese acetate. Typical rhenium compounds are perrhenic acid, ammonium perhenate and potassium perhenate. Typical palladium compounds for use in the impregnation solution are tetrachloropalladic acid (H ₂ PdCl ₄ ), palladium nitrate, palladium (II) chloride and amine complexes thereof. Preference is given to the use of H ₂ PdCl ₄ . Common platinum compounds for use in the impregnation are hexachloroplatinic acid (H ₂ PtCl ₆ ), optionally in the presence of hydrochloric acid, platinum amine hydroxides and suitable platinum amine complexes.

It is common in catalyst production to calcinate the catalyst in air at the final stage to make the metal in its oxide form. To convert the metal to at least some of its sulfides, the catalyst can be presulfurized after the final firing step and before contacting the feed. Suitable presulfurization methods are known in the art, for example from European Patent Application Publication Nos. 0,181,254; 0,329,499; 0,448,435 and 0,564,317 and WO 93/02793 and WO 94/25157. Thus, in another embodiment of the invention, the catalyst preparation method further comprises the following steps:

(c) presulfurization of the dried and calcined catalyst.

Instead of the presulfurization method, presulfurization may also occur via in situ presulfurization. This involves contacting the calcined catalyst with a sulfur-containing hydrocarbon feed under suitable conditions (usually less severe than those applied during the operation under consideration).

The catalyst according to the invention can be regenerated by known methods in the art. Conventional methods of regenerating catalytically active metals from the catalysts used are to remove the deactivated catalysts from the reactor, wash the catalysts to remove hydrocarbons, burn the coke and recover the precious metals (classes) and manganese and / or rhenium. It includes.

Example 1

An acidic carrier containing 80% by weight of dealuminated zeolite Y (unit cell size 24.25 mm 3 and silica / alumina molar ratio 80) and 20% by weight alumina binder is used. This carrier sample is impregnated with an aqueous solution of perenic acid (HReO ₄ ) to give 20% by weight ReO ₂ (corresponding to 17.1% by weight; the weight percentage is based on the total weight of the carrier). The partially prepared catalyst is then dried and calcined at 400 ° C. for 2 hours and then impregnated with an aqueous solution of H ₂ PdCl ₄ to give a PdO content of 5 wt% (corresponding to 4.3 wt% of Pd). Finally, the finished catalyst is dried and calcined at 350 ° C. for 2 hours in air. This catalyst is also described as PdRe / Y.

Example 2

A layer of said PdRe / Y 20 cm ³ mixed with silicon carbide particles (SiC; 0.21 mm diameter) 80 cm ³ is installed in the reactor. The PdRe / Y layer thus obtained is presulfurized according to the method described in EP-A-0,181,254. This method involves impregnation with di-t-nonyl polysulfide diluted in n-heptane followed by drying for 2 hours at 150 ° C. under nitrogen at atmospheric pressure. The catalyst is then activated by making the total pressure of the reactor 50 bar using a gas volume of 500 Nl / kg. After raising to 250 ° C. from ambient temperature for 2 hours, the feed is introduced and heated from 250 ° C. to 310 ° C. at a rate of 10 ° C./hr. Temperature 310 degreeC is hold | maintained for 100 hours.

After the activation procedure is completed, the feed having the characteristics shown in Table I (BP represents boiling points, IBP and FBP respectively represent initial and final boiling points) is passed over the PdRe / Y layer. The feed is a mixture of 75% by weight straight run gas and 25% by weight light cycle oil. Process conditions include a weight average bed temperature (WABT) of the PdRe / Y layer at 350 ° C., a total pressure of 50 bar, a gas volume of 500 Nl / kg and a weight hourly space velocity (WHSV) of 1.0 kg / l · h.

Feed characteristics S (% wt) 1.37 BP distribution (℃) N (ppmw) 228 IBP10% wt50% wt90% wtFBP 150229287357424 Aromatic Compounds (mmol / 100 g) Monodipoly 77.355.320.4

Sulfur content and nitrogen content (all ppmw), decomposition levels expressed in weight percent of formed material having a boiling point below the IBP of the feed (ie 150 ° C.) and mono-, di-, and poly-aromatic compound content (mmol / 100 grams of product) is measured.

The results are shown in Table II below.

Product properties product S (ppmw) N (ppmw) Decomposition (% wt 150 ℃ ^- ) 5197.22 Aromatic Compound (mmol / 100 g) Monodipoly 66.06.33.0

From Table II the decomposition of the feed component to low boilers is reduced to a minimum and the hydrodesulfurization activity and the hydrodenitrification activity of the PdRe / Y catalysts are excellent; It can be seen that the sulfur- and nitrogen-content decreased 96.2% and 96.8%, respectively.

Table II also shows very good conversion of aromatics. In this regard, it should be borne in mind that the conversion of poly (tri +) aromatic and diaromatic compounds increases the initial monoaromatic compound content. The conversion rate (in% wt) can be calculated assuming that the aromatic compound is hydrogenated through a continuous reaction path, that is, the polyaromatic compound is a diaromatic compound, the diaromatic compound is a monoaromatic compound and the monoaromatic compound is a naphthenic compound. Assume that is switched to. This is a valid assumption since the hydrogenation of aromatic rings contained in the multinuclear structure is generally less favorable mechanically as the number of aromatic rings in the multinuclear structure decreases. The monoaromatic compounds thus found in the product come from three sources: (i) unconverted monoaromatic compounds in which the feed already exists, (ii) converted diaromatic compounds originally present in the feed and (iii) their Instead, converted diaromatic compounds derived from the converted polyaromatic compounds present in the feed. Based on the continuous route mechanism, the conversion levels of the polyaromatic, diaromatic and monoaromatic compounds are 85.3%, 91.3% and 54.1%, respectively.

Example 3

5% by weight of PdO (corresponding to 4.3% by weight of Pd) and 5% by weight of ReO ₂ on an acidic carrier consisting of 65% by weight of modified zeolite Y (unit cell size 24.32 mm 3 and silica / alumina molar ratio 9.2) and 35% by weight silica The procedure of Example 2 is repeated except that a PdRe / Y catalyst comprising, corresponding to 4.3% by weight of Re) is used.

The feed is a mixture of light cycle oil and direct current diesel with the characteristics shown in Table III below, and the process conditions used are exactly the same as before except that the feed is in contact with the catalyst at a temperature of 360 ° C.

Feed characteristics S (ppmw) 3900 BP distribution (℃) N (ppmw) 320 IBP10% wt50% wt90% wtFBP 196287358403435 Aromatic Compounds (mmol / 100 g) Monoditripoli (tree +) 54.424.89.814.8

Both the sulfur content and nitrogen content (all ppmw units), the decomposition level expressed in weight percent of the formed material below the boiling point below 150 ° C. and the percentage conversion of mono-, di- and triaromatic compounds are measured.

The results are shown in Table IV.

Product properties product S (ppmw) N (ppmw) Resolution (% wt 150 ℃ ^- ) 38039.00.9 Aromatic Compound Conversion (%) Monoditree 50.281.373.1

Example 4

The procedure of Example 3 is repeated, except that the process temperature is increased to 380 ° C. to carry out the process in a mild hydrocracking mode (as opposed to the hydrotreating mode of Example 3). All other process conditions are the same.

The sulfur content and nitrogen content (all ppmw units), the decomposition level expressed in weight percent of the formed material below the boiling point below 150 ° C., the percentage conversion and the pour point of the mono-, di- and triaromatic compounds are all measured.

The results are shown in Table V.

Product properties product S (ppmw) N (ppmw) Resolution (% wt 150 ℃ ^- ) 24 <118.9 Aromatic Compound Conversion (%) Monoditree 44.085.185.1 ^* Pour point (℃) -3 ^* Pour point of feed is 15 ° C.

Claims (14)

A catalyst comprising from 0.1 to 15% by weight of a noble metal selected from at least one of platinum, palladium and iridium, and from 2 to 40% by weight of manganese and / or rhenium supported on an acidic carrier, said weight percentage being based on the total weight of the carrier The amount of metals). The catalyst of claim 1 comprising 3 to 10% by weight of precious metals and 2 to 30% by weight of manganese and / or rhenium. The catalyst of claim 1 or 2 comprising palladium and rhenium. The catalyst according to claim 1, wherein the acidic carrier comprises aluminosilicate zeolite, silicoaluminophosphate, amorphous silica-alumina, alumina, fluorinated alumina, phyllosilicate or a mixture of two or more thereof. . The catalyst of claim 4 wherein the acidic carrier comprises aluminosilicate zeolite. 6. The aluminosilicate zeolite of claim 5, wherein the aluminosilicate zeolite has a unit cell of size less than 24.60 mm 3, preferably 24.20 to 24.45 mm 3, and a SiO ₂ / Al ₂ O ₃ molar ratio in the range of 5 to 150, preferably 5 to 110. Having a modified zeolite Y catalyst. The catalyst according to claim 1, wherein the acidic carrier also comprises 5 to 95% by weight of binder, preferably silica and / or alumina. Use of a catalyst according to any of claims 1 to 7, in a hydrocarbon feed comprising an aromatic compound is contacted with the catalyst at high temperature and high pressure in the presence of hydrogen. 9. Use according to claim 8, wherein the hydrocarbon feed also comprises sulfur and / or nitrogen containing compounds. 10. Use according to claim 8 or 9, wherein the process is a hydrotreating process. Use according to claim 8 or 9, wherein the method is a lubricating base oil manufacturing method. 10. Use according to claim 8 or 9, wherein the process is a hydrocracking process. A process for preparing a catalyst according to any one of claims 1 to 7, comprising incorporating a catalytically active metal into the carrier, followed by drying and calcining. The method of claim 13, comprising the following steps: (a) impregnating the carrier with one or more solutions containing noble metal compounds selected from compounds of platinum, palladium and iridium, and one or more solutions containing manganese and / or rhenium compounds, optionally drying and / or calcining; (b) the impregnated carrier is dried and calcined at a temperature of 250 to 650 ° C., and then optionally (c) Presulfurization of the calcined catalyst obtained in step (b).