GB1563593A

GB1563593A - Catalysts for demtallization tretment of hydrocarbons supported on sepiolite

Info

Publication number: GB1563593A
Application number: GB5074576A
Authority: GB
Original assignee: Chiyoda Chemical Engineering and Construction Co Ltd
Current assignee: Chiyoda Chemical Engineering and Construction Co Ltd
Priority date: 1975-12-09
Filing date: 1976-12-06
Publication date: 1980-03-26

Description

(54) CATALYSTS FOR DEMETALLIZATION TREATMENT OF HYDROCARBONS SUPPORTED ON SEPIOLITE (71) We, CHIYODA CHEMICAL ENGINEERING & CONSTRUCTION COM PANY LIMITED, a company organised and existing under the laws of Japan, of 1580, Tsurumi-cho, Tsurumi-ku, Yokohama-shi, Kanagawa-Pref., Japan, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a catalyst for the hydrogenation or selective demetallization treatment of hydrocarbons, to a method for the preparation of the catalyst and to a process for the hydrogenation and demetallization of hydrocarbons, particularly heavy hydrocarbons, in the presence of the catalyst under a hydrogen pressure and at a high temperature.

Impurities such as sulfur, nitrogen and metals are contained in hydrocarbons including crude oils, heavy oils, cracked oils, deasphalted oils, topped residual oils, vacuum gas oils, tar sands, bitumens, shale oils, or the mixtures thereof. These impurities are discharged into the atmosphere together with the exhaust gas when these hydrocarbons are subjected to combustion, becoming a source of environmental pollution. Also, the soluble metals contained in the hydrocarbons are deposited on a catalyst in the catalytic treatment of hydrocarbons, causing a marked decrease in the catalytic activity of the catalyst and the selectivity of the reaction. Therefore, in order to utilize the hydrocarbons as a harmless energy source or as the starting material in a catalytic process, it is necessary to remove sulfur, nitrogen and metals from them beforehand. Above all, it is becoming an indispensable requisite that the metals are removed previous to the treatment of non-metallic impurities such as sulfur and nitrogen. Since these metals were, heretofore, simultaneously treated together with sulfur, nitrogen and the like without subjecting to any pretreatment, it was necessary to use the catalyst in an amount in large excess to the theoretical amount required for desulfurization or denitrification. But as the catalysts for these desulfurization and denitrification are very expensive the development of an inexpensive catalyst which is capable of effective demetallization has been desired.

In the prior art, when demetallization treatment is carried out beforehand, hydrocarbons are treated by utilizing either an ordinary desulfurization catalyst or a waste catalyst having almost no desulfurization activity, or using a catalyst such as bauxite or red mud in a so-called guard reactor. All these catalysts, however, have defects in that the activity of demetallization is low or the life time of the catalysts is too short, and moreover, they are very unsatisfactory for the purpose of carrying out a selective and effective demetallization reaction.

In the case of a catalyst having a relatively high demetallization activity, usually the desulfurization reaction also proceeds simultaneously, and as a result this often causes trouble in the utilization of the hydrocarbons thus demetallized. For example, red mud is available at a very low price and in quantities and is a useful catalyst for demetallization having the activity of removing, under a high hydrogen pressure, the metals contained in hydrocarbon oils, especially vanadium, nickel and iron. But, it has defects in that the demetallization treatment must be carried at high temperatures requiring a very long contact time. The oil treated in the presence of the red mud-catalyst is extremely instablized as a result of a long residence time at a high temperature, and further it may happen that carbonaceous substances are caused to be deposited to clog the reactor near the exit of the catalyst layer. In order to avoid such trouble the treatment may be carried out at a relatively low temperature, but it takes a still longer time and is very disadvantageous from an economical viewpoint because of the necessity of providing a large-sized reactor.

Bauxite is also available at a price as low as that of red mud and has a demetallization activity higher than that of red mud. But, bauxite has defects in that the lowering in the activity is considerably large on account of its small pore volume and the life time of catalyst is short. A catalyst having such a small pore volume as bauxite is not suitable for the treatment of hydrocarbons containing a high content of metals.

Incidentally, the demetallization reaction of hydrocarbons is the so-called hydrogenation reaction which is carried out in the presence of a catalyst under a hydrogen pressure and at a high temperature. It has been known for a long time that the demetallization reaction takes place together with a desulfurization reaction since metals are deposited on a catalyst in the course of the desulfurization reaction. In the desulfurization treatment using a conventional desulfurization catalyst, the higher the desulfurization ratio is raised, the higher the demetallization becomes, and the desulfurization and demetallization reactions take place in an almost definite proportion under the same condition. On the contrary, even when demetallization is carried out by using a conventional desulfurization catalyst, it is totally impossible to avoid the desulfurization reaction which takes place in the definite proportion. These phenomena will be further studied in comparison with the effects obtained by the present invention in the following.

The present invention provides a catalyst for hydrotreating hydrocarbons, particularly for the demetallization of hydrocarbons, which comprises an effective amount of one or more of the compounds specified below supported on sepiolite that has been treated by the successive steps of: (a) adding water to natural sepiolite or to sepiolite that has been crushed or ground, (b) kneading the mixture and adjusting the water content thereof to from 20% to 350% by weight, calculated on the weight of the sepiolite (in either order), and (c) air-drying or heat-treating the mixture at a temperature less than 1000"C. The selected compounds are compounds of: Cu, Ag, Au, Zn, Cd, Hg, Sc, Y, the lanthanides, the actinides, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Te, Re, Fe, Co, Ni, Ru, Rh, Pd, Os, Ir and Pt.

The catalyst may be prepared according to the invention by adding the compound(s) to sepiolite before, during or after the above treatment.

The invention also provides a method for desulfurization, denitrification and/or demetallization of hydrocarbons which comprises treating the hydrocarbons in the presence of pressurized hydrogen and at a high temperature by using a catalyst according to the invention.

When compared with a conventional desulfurization catalyst a catalyst of the present invention has a far larger ratio of demetallization rate to desulfurization rate and provides a more selective demetallization reaction. Thus, the catalysts of the invention are very valuable for industrial use as novel catalysts for demetallization. Further, the catalysts have a high hydrogenation activity and a long lifetime for treatment of hydrocarbons.

The invention is illustrated by the drawings of which: Figure I is a photomicrograph (magnification x 10,000, with an electron microscope) of natural sepiolite of Spanish origin which was ground into a powder 50 mesh or smaller in size and subjected to moisture conditioning. Figure 2 is a photomicrograph (magnification x 10,000) of the above-mentioned moist sepiolite which was kneaded by passing through an extruder 3 times. Figure 3 and 4 are graphs showing the changes in the distribution of specific surface areas as well as those of pore volumes in the stages of grinding, kneading and molding of sepiolite. Figure 5 shows the changes in the results obtained by X-ray diffraction tests of the starting material sepiolite and the sepiolite which was not incorporated with additives but was baked at 250"C, 450"C or 650"C, in comparison with the result from the test of the molded product (calcined at 5000C) which was prepared according to the present invention.

The selected compounds that are supported on the sepiolite in the catalyst of the invention are preferably Co, Ni, Fe, Cu, lanthanides, V, Cr, Mo and W. Furthermore, the use of both one or more compounds of the metal(s) selected from Co, Ni, Fe, Cu, and lanthanides, and one or more compounds of the metal(s) selected from Mo, W and V is especially effective in the present invention.

These compounds are generally nitrates, sufates, salts of metallic acids, complex salts or other water-soluble compounds. The addition of these compounds to sepiolite can be conducted according to the conventional methods such as immersion, spraying and kneading. These compounds are employed generally in an amount of 0.1 to 20% by weight (as metal) on the basis of carrier (as anhydride), and usually 0.2 to 10 % by weight will suffice.

Sepiolite is a porous magnesium silicate mineral which is also called meerschaum. The sepiolite naturally occurs as a secondary mineral in a serpentine; and its synthetic product was prepared from cheaply available silicic compounds and magnesium salts in 1935 or so and is now marketed under the trade name of "magnesium trisilicate". For the purpose of the present invention, any natural or synthetic sepiolite can be employed, and both the a type-sepiolite and ss type-sepiolite that are known to exist can be used in the present invention. The sepiolite may be used as it is or it may be dried at below 200"C, usually at 100"C to 1200C, to remove the adhered moisture, and ground to a desired particle size. In general, the sepiolite having a particle size of 0.3 to 3 mm in volume average diameter is employed. If necessary, sepiolite can be treated in combined steps of grinding, molding and sintering so as to meet the particular use purpose. The size and shape of the carrier can be suitably selected in accordance with the reaction conditions of hydrotreating and the types of the reaction apparatus.

In the case of some metals, the ion-exchange property of sepiolite can be utilized to have the metals supported on sepiolite. These metals include those of Groups Ib, IIb, IIIa and VIII of the Periodic Table according to Mendeléef and preferably Co, Ni, Fe, Zn, Cu and lanthanides. By contacting an acidic aqueous solution of these metal ions with sepiolite, magnesium contained in the sepiolite is ion-exchanged with these metals to have these metals supported on the sepiolite. These metals may be used in the form of an aqueous solution of the salts of mineral acids such as chlorides, sulfates and nitrates and/or the salts of organic acids such as formates and acetates. If necessary inorganic acids or organic acids are added to the solution so as to adjust the pH of the solution to 1 - 7.

The concentration of the metallic salt(s) in the aqueous solution is determined according to the amount of the metal(s) to be supported, the kind thereof and the condition of the supporting treatment. When a concentrated solution is employed, magnesium contained in seplolite tends to elute from the sepiolite in larger amounts relative to the amount of the metal to be supported. Therefore, in the case where too high a concentration is employed, the structure of sepiolite may be destroyed until it eventually pulverizes. A similar phenomenon may take place when an inorganic acid or an organic acid is added to the solution in an extremely large amount. Therefore, it is necessary to employ the acidic solution having a pH in the range of 1 to 7 as above described. A solution having a pH lower than 1 may also be used, but in this case the treatment should be conducted in a very short period of time. It is important that while the metal is supported on the carrier, a portion of the magnesium contained in the sepiolite is allowed to dissolve, as already described.

Accordingly, it is presumed that the metal is ion-exchanged with a considerable amount of the magnesium when it is supported on the sepiolite. The metal thus supported does not dissolve even when rinsed with pure water, but dissolves in an acidic solution. The usefulness of the catalyst of the invention resides in the fact that the metal supported is substituted for magnesium, and the metal simply deposited on the sepiolite without being substituted is lower in the catalytic activity per unit weight of the metal than that of the metal substituted. Therefore, it is desirable that the metal simply deposited on the sepiolite is removed by rinsing and effectively reused.

The sepiolite thus treated to support the metal and rinsed can be used as it is, or after drying or baking at a temperature below 1,000"C, or after grinding and molding into the desired shape.

When both metal(s) which can be supported according to the ion-exchange method and metal(s) which cannot be supported thereby are to be supported on the same sepiolite, the conventional impregnating method, spraying method and the like can be applied using an aqueous solution containing both the metals; but, it is very effective for the activity of the resulting catalyst to support the former metal(s) by the ion-exchange method and then to support the latter metal(s) as an aqueous ammonia or amine solution thereof. In such a catalyst preparation process, however, the supporting treatment should be carried out by an ion-exchange reaction using an acidic aqueous solution in the first step, and using a basic aqueous solution in the second step, the first and second steps being carried out in this order.

Usually, the metal supported in the first step is not the same as the metal supported in the second step, but if desired, the same metal can be supported in these two steps. In the first step, the magnesium contained in sepiolite is substituted by the metal dissolved in an acidic aqueous solution through an ion-exchange reaction, while in the second step, the supporting is the same as that achieved by the conventional impregnating method.

Therefore, it is considered that the metal in the first step is supported in a state quite different from the metal in the second step. These states of the metals supported cannot be distinguished from each other according to ordinary analysis or by an observation of the microstructure. But, as a clear difference is found in the catalytic activity, after metals have been supported between the catalyst prepared by these two-step method and the catalyst obtained by a one-stage method, it is judged that each of the metals treated according to the two-step method of the present invention is supported in a structurally different state from the metals treated by the one-stage method, and thus, this results in the difference in catalytic activity.

The kind and amount of the metal(s) to be supported in the first step are generally determined in accordance with those of the metal(s) to be supported in the second step, but as the amount of the metal to be supported in the first step 0.1 to 5 % (as metallic element) by weight will suffice.

In general, the sepiolite treated in the first step is rinsed with pure water and/or an aqueous solution containing acid, ammonia or an amine and then, if necessary, dried or baked at a temperature below 1,000"C, followed by the treatment in the second step. In the above case it is essential that the metals supported in the first step are substituted for magnesium, and since the catalytic activity per unit weight of the metals simply adhered on the sepiolite without being substituted is lower than that of the metals substituted, the excess of these metals is removed by rinsing and effectively reused. When the washing is with an aqueous acid solution the metal ion(s) to be supported on the carrier may if necessary, be contained in the solution. The sepiolite treated in the first step and then rinsed is usually as such, or after drying below 1,000 C, subjected to the second step, but alternatively, it may also be ground and molded to the desired shape before subjecting to the second step.

The second step comprises supporting on a carrier one or more metals selected from the group consisting of metals of Groups Va and VIa, and VIII of the Periodic Table according to Mendeléef and Cu, preferably from the group consisting of Mo, W, V, Ni, Co and Cu by impregnating said carrier with an aqueous ammonia and/or amine solution containing these metals. This step is substantially the same as the conventional method for supporting a catalytic metal on a carrier. As these compounds use is made of ammonium paramolybdate, ammonium silicotungstate, ammonium paratungstate, ammonium vanadate, or chlorides, sulfates, nitrates or formates of Ni, Co, Cu, and the like. Of course, other prior known compounds which are stable or can be converted to soluble compounds in a basic aqueous solution can also be used. These compounds are used by dissolving them homogeneously in an aqueous ammonia solution or an aqueous amine solution. The concentration of these metallic compounds as well as of ammonia or amines in the basic aqueous solution can be determined according to the amount of the metal to be supported and the properties of the sepiolite carrier treated in the first step. The metal to be supported in the second step can be treated in one-stage or multistage process. As the amount of metal to be supported in the second step generally 20 % or less (as metal) by weight will suffice, but it is preferably 2 to 20 % by weight for the metals Mo, W and V and 0.1 to 10 % by weight for Ni, Co and Cu.

The sepiolite carrying metallic compounds is generally baked or sintered at a temperature of 300C to 1 ,0000C, preferably 350C to 800"C, for use, but before use, it may also be pretreated, if necessary, such as by subjecting to sulfidizing, etc, in its impregnated state without being baked or sintered.

The sepiolite used as the catalytic carrier in the present invention is a porous substance which not only occurs naturally as a hydrous magnesium silicate but also is readily available as a synthetic product, and is widely used as a catalytic carrier as well as an adsorbent and the like. The natural sepiolite, however, is not constant in the properties such as composition, pore volume, specific surface area, pore distribution and crushing strength.

Further, when it is wanted to obtain this material of a given particle size by crushing and sieving of its mineral the yield is very poor.

Although sepiolite itself is a very porous substance having a large pore volume, it is not only difficult to obtain the material of uniform quality, but also most of the material, as it is, is not always so porous as to be sufficient for specific purposes. Moreover, the pore distribution of natural sepiolite covers a very broad range. The present inventors have found that the proportion of the volume of large pores more than 600it in diameter occupying in the whole pore volume often accounts for 35 % or more. The larger the proportion of such large pores, the smaller the specific surface area as well as the crushing strength of crushed product. Therefore, in some cases, where it is used as catalytic carrier, such crushed sepiolite as it is, is not undesirable in practice for specific purposes.

The present inventors investigated the properties of the sepiolites produced naturally in various countries as well as their useful application, and as a result found that sepiolite is a mineral having very unique properties and can be made into a molded product having excellent properties by subjecting it to specific treatment. Thus, the inventors have further succeeded in obtaining an excellent catalyst by modifying the sepiolite used as catalytic carrier. The porous molded product prepared according to the present invention has the following characteristics: (a) sepiolite having markedly large pore volume and specific surface area in comparison with those of the raw sepiolite can be readily obtained; (b) sepiolite having a larger specific surface area can be obtained by making the size of the pore volume comparable to, or smaller than that of the raw sepiolite; (c) the molded sepiolite has a sharp pore distribution; and (d) the molded sepiolite has a large crushing strength.

The relation between the pore volume and the specific surface area of the molded product obtained according to the present invention is not necessarily critical, but it is possible to prepare the molded product having the desired pore volume and specific surface area.

It has been recognized by the present inventors that the porous molded product having the above-described excellent properties obtained according to the present invention is much improved in the fundamental structure of sepiolite in that the molded product is clearly different from the raw sepiolite in both the physical and chemical properties from the physical and chemical studies such as composition analysis, X-ray diffraction, measurement of specific surface area, measurement of pore distribution, observation under an electron microscope, measurement of crushing strength and the like of the raw sepiolite, the intermediate product and the final product.

Since the above-mentioned change in fundamental structure is scarcely observed in the molding step of the ordinary porous powder materials, it is considered that such a change is peculiar to sepiolite and has an excellent effect on the catalyst of the present invention.

Now the molding of sepiolite will be explained in the order of the procedure. Natural or synthetic sepiolite as raw material is ground by a grinder. The particle size of the resulting sepiolite powder may be in such a range as not to cause difficultv in the kneading or molding process and is generally desirably smaller than 50 mesh (U.S. Standard screen size).

However, in order to carry out the kneading efficiently it is preferable to make the particle size as fine as possible. Accordingly, sepiolite is generally ground to a fine powder in which 100-mesh or finer powder accounts for 50 W0 or more. The method for grinding is not especially restricted, and either a wet method or a dry method can be employed.

The ground sepiolite is then treated in the following kneading step. One of the main characteristics in the process of the present invention is that the ground sepiolite is subjected to moisture conditioning and to sufficient kneading or mastication. In the step prior to the kneading, water is added to the ground sepiolite so as to carry out the kneading effectively and the following molding efficiently and smoothlv.

The final water content of the resulting moist sepiolite has a large effect on the properties of the resulting catalyst and on the molding properties as well. The water content, therefore, is determined in consideration of the properties of the raw sepiolite, the amount and kind of the additives later described, the properties of the kneaded material, the method for molding and the purpose of using the resulting catalyst. The water content of the sepiol;te is adjusted to from 20 to 350 % by weight. calculated on the weight of anhydrous sepiolite, preferably to from 50 to 280 8Xr by weight. When the water content is less than 20 %, it is difficult to obtain the catalyst having the desired properties as well as to mold it according to the ordinary molding method. When the water content is more than 350 %, a sufficient crushing strength of the resulting catalyst cannot be obtained and such water content is not practicable. In the case where additives are used in combination, the above-mentioned range of water content can be applied to the amount of a mixture of sepiolite and the additives. When the moist sepiolite is to be molded by an extruder. its water content is preferably in the range of 80 to 350 Nc by weight. and when it is to be molded by a tableting machine, its water content is preferably in the range of 20 to 100 % by weight.

The above-mentioned range of water content is very large in comparison with those in the case where alumina, alumina-silica and the like are used as raw materials. This is due to the structure of sepiolite, and such a large amount of water acts effectively in the kneading step.

In general, the kneading of porous powder is conducted to effect uniform dispersion of moisture and homogenizing of the components of the mixture. In the case of the kneading of moist powder in the molding of porous powder such as alumina and alumina-silica, it is known that the specific surface area and pore volume of the kneaded material gradually decrease as the kneading proceeds. Therefore. it has been the technical common sense that the kneading is suppressed to such a minimum degree as required for enhancing the molding properties or crushing strength. Unexpectedly, in the case of sepiolite, the more sepiolite is kneaded, the larger the pore volume and pore surface area become and the sharper the pore distribution becomes.

In order to clarify these unique properties, sepiolite was observed under an electron microscope (magnification x 10,000) to reach the following conclusion.

Referring now to the drawings, the photomicrograph (magnification x 10,000) of the sepiolite simply ground to fine powder indicates that the sepiolite fibers stick to one another to form thick fascicular fibers or lumps as clearly shown in Figure 1. Whereas, the photomicrograph of the sepiolite which was subjected to grinding and moisture conditioning followed by sufficient kneading indicates that the thick fascicles and lumps of sepiolite fibers almost disappear, and short and thin fibers are scattered in disorder, as shown in Figure 2. Accordingly, when the molded sepiolite having such a structure as shown in Figure 1 is compared with the one having such a structure as in Figure 2, it will be readily understood that the specific surface area and pore volume of the latter are markedly increased in comparison with those of the former.

This phenomenon can also be proved by the changes in the distribution of specific surface area as shown in Figure 3 as well as in the distribution of pore volume as shown in Figure 4 in each step of grinding, kneading and molding of sepiolite which was treated in this order.

It is shown in Figure 3 that the specific surface area of the kneaded material (3) or the molded material (4) is markedly increased in comparison with that of the sepiolite ore (1) or the ground sepiolite (2), and further the surface area of the pores 600A or smaller in diameter is markedly increased in the step of kneading although the surface area of the pores larger than 600it in diameter is not substantially altered by the kneading treatment.

In Figure 4, it is also shown that the pore volume of the kneaded material (3), especially of the pores 600A or smaller in diameter, is increased. In addition, in each of the data shown in Figures 3 and 4, no additive was contained in (1) and (2), but (3) and (4) contained 10 % (as alumina) by weight of alumina sol on the basis of dry sepiolite.

The above-mentioned kneading can be carried out by an ordinary kneader, roll mill or molding machine such as an extruder, and may be done by any other means which can untie the sepiolite fibers to separate fibers in the presence of water. The purpose of the kneading is to increase the specific surface area and the pore volume of the sepiolite, and the method and period of time for the kneading can be determined according to the properties of the resulting molded product, the properties of the raw material, the presence or absence of additives, the properties of the moist material, the type of the kneader, and the like.

Incidentally, the kneaded material can be again subjected to moisture conditioning, if necessary, to adjust the water content thereof to a suitable molding condition.

The sepiolite material which was subjected to kneading and moisture conditioning is air-dried and/or baked at a temperature below 1,000"C. The moist sepiolite material can be subjected to air-drying and/or baking in its original kneaded form or after molding it by conventional molders such as extruders and tabletting machines. The material which was air-dried and/or baked can be ground to a desired particle size for use in a slurry or paste form. The shape and size of the resulting catalyst is determined according to the purposes of use and process. The crushing strength of the resulting catalyst can also be controlled to meet the condition of use by selecting a suitable method for preparation and a suitable temperature of drying and baking.

The present inventors found that the properties of the molded sepiolite can be further improved by incorporating the following additives in the sepiolite material in the course of molding.

Mainly for the purpose of enhancing the crushing strength of the resulting catalyst, one or more additives selected from the following additives can be added to sepiolite: (a) aluminium hydroxide sol, alumina employing the resulting catalyst, and these additives may be added to sepiolite in a large excess if so required. The additives selected from each of the groups (a), (b) and (c) can be used in combination to enhance the various effects on the resulting catalyst. These additives are generally added to sepiolite in the course of kneading in the form of ground powder or paste, and may be admixed to sepiolite prior to supporting metals such as Co and Ni on sepiolite.

Besides these additives, to the sepiolite mixture may be added any of the compounds suitable for use in the pre-treatment of sepiolite (which is a preferred treatment of sepiolite and is explained below in detail) such as inorganic acids, organic acids, metal or ammonium salts thereof, salts of ammonia derivatives, or magnesium salts. Of course, it is not necessary to add the compounds when the compounds employed in the pre-treatment remain in the sepiolite material.

The common effect obtained by addition of these additives is that a very excellent thermal stability is exhibited when molded materials containing the additives are subjected to calcining or sintering, in comparison with the case where no additives are added. This effect is concretely indicated by an increase in strength, an increase in pore volume and the like, but most distinctly exhibited by the X-ray diffraction of the sintered product from the viewpoint of its structure. As shown in the graph of Figure 5, the results of X-ray diffraction of raw sepiolite (1) air-dried at room temperature and sepiolite (2) dried at a relatively low temperature of 250"C indicate substantially the same patterns. While, in the X-ray diffraction of sepiolite (3) or (4) calcined at 450"C or 650"C, a peak in the neighborhood of 2H = 7" disappears and the changes in other small peaks are observed. In the case of the molded product (5) which was prepared by adding the additives to the same sepiolite and calcining at 500"C, the peak in the neighborhood of 20 = 7" does not disappear but remains as it is and other small peaks are more similar to those of (1) and (2) than 03) and (4). From these results, it is clear that the additives have some effects on the thermal stability of sepiolite.

The effects of some of the additives on the molded products are more concretely explained as to each group of the additives in the following.

The additives shown in the groups (a) and (b) serve to enhance the crushing strength of the molded products, without substantially decreasing the pore volume. Especially, aluminium salts of the group (a) serves to markedly decrease the large pores 400A or more in diameter in the pore distribution and to increase the pore volume within the range of pores 400A or less in diameter. Furthermore, the addition of the aluminium salts results in the marked enhancement of crushing strength of the resulting molded product, even in a very small amount. The presence or formation of acids in the sepiolite mixture results in the especially sharp distribution of pores. Such sharp distribution is also obtained by addition of the metal salts.

These additives can be added to sepiolite in the course of grinding. moisture conditioning or kneading, alone or together with the additives of the other group shown above.

In the preparation of the catalyst using a sepiolite carrier for hydrotreating according to the present invention, the following pretreatment step can be employed to enhance the catalytic properties and to improve the method for preparation of the catalyst.

A small amount of impurities such as calcium carbonate, magnesium carbonate and magnesium-calcium carbonate may be contained in the sepiolite generally employed.

Although some of these impurities are removed in the course of the metal-supporting step using an acidic aqueous solution, the remaining impurities may have an adverse effect on the activity of the resulting catalyst, especially on the hydrogenation activity thereof such as those of desulfurization and denitrification. Further, the presence of these impurities results in a decrease in the crushing strength of the resulting catalyst since some of the impurities are dissolved in the course of the metal-supporting step. Also, a further complicated treatment is required to recover the waste liquid in which these impurites were dissolved, in the metal-supporting step.

A pretreatment step that is optionally employed in the present invention has substantially eliminated the above-mentioned defects.

In the pretreatment step, there is employed an aqueous solution containing one or more of the compounds selected from magnesium salts, inorganic acids such as mineral acids and carbonic acid, organic acids, ammonium salts and salts of ammonia derivatives.

Incidentally, the mineral acids include nitric acid, sulfuric acid, hydrochloric acid and phosphoric acid. The organic acids include formic acid, oxalic acid, acetic acid and tartaric acid. Carbonic acid is usually employed in the form of an aqueous solution in which carbon dioxide was dissolved under normal or higher pressure. The ammonium salts include ammonium nitrate, ammonium sulfate, ammonium phosphate, ammonium carbonate, ammonium oxalate, ammonium acetate and ammonium tartarate. The salts of ammonia derivatives include trimethylamine hydrochloride, and aniline hydrochloride.

The composition and concentration of these treating liquids are not especially restricted.

It is generally effective to employ a solution having a pH in the range of 1 to 7, but an acidic solution of pH lower than 1 may be used at a low temperature and with a short-time treatment.

The pretreatment is not especially restricted as to the temperature and time of the treatment, and is generally carried out at a temperature below 100"C and for more than several minutes. The pretreatment may be performed in a shorter time depending on the properties of sepiolite to be treated.

In the course of the pretreatment, magnesium elutes in the treating solution, and the amount of the magnesium eluted depends on the treating condition of sepiolite. In general, the lower the pH of the treating solution is, the longer the treating time is, or the higher the treating temperture is; the larger the amount of magnesium to be eluted becomes.

The present inventors have found that magnesium to be eluted comes from magnesium hydroxide, magnesium carbonate and dolomite components which are present as impurities in sepiolite, by observing the state of sepiolite before and after the pretreatment was effected. Thus, the present inventors have got information that one of the reasons that the pretreatment has a good effect on the subsequent metal-supporting step is due to the elution of most of the impurities from sepiolite.

The present inventors have further found that the properties of the resulting sepiolite catalyst, such as physical property, activity, reaction selectivity and lifetime, depend largely on the preparation process such as method of supporting metals, method of pretreating sepiolite and method of molding.

A method for preparation of the catalyst based on the effective combination of the above-mentioned steps is illustrated in the following.

If a metal or metals such as Co and Ni were supported on sepiolite by way of ion-exchange reaction the pore volume and specific surface area of the sepiolite would be decreased owing to a phenomenon which has not yet been fully explained but is presumed to be due to electrostatic intermolecular force. Accordingly, the overall performance of the catalyst for hydrotreating hydrocarbons is not satisfactorily exhibited, although the activity of catalytic metal is increased by employing the ion-exchange method.

A satisfactory metal on sepiolite-catalyst can be obtained by the following procedure.

Before having a metal or metals supported on sepiolite, water is added to sepiolite. The mixture is subjected to a sufficient kneading or mastication to obtain a carrier material having such pore volume and specific surface area as are desirable for a catalytic carrier, followed by adjusting the water content thereof. The sepiolite thus treated is, as it is or after moulding, subjected to drying, baking or calcining to fix the desired pore volume and specific surface area obtained by the kneading. The resulting sepiolite is treated with an acidic solution containing a metal or metals such as Co and Ni according to the ion-exchange method, to have the metal supported thereon, The method for preparation of the present catalyst comprises the steps of (i) adding water to natural sepiolite or to sepiolite that has been crushed or ground, (ii) kneading the mixture, (iii) adjusting the water content to from 20% to 350% by weight, (iv) air-drying or calcining the mixture at less than 1000 C, and (v) adding the one or more compounds to the sepiolite. The order of steps (i) to (iv) may be (i), (ii), (iii). (iv) or (i), (iii). (ii), (iv), and the addition of the selected compounds (step (v)) may be before, during or after steps (i) to (iv).

In this method. it is preferable that the baking or calcination should be carried out at a temperature below 400"C. When the calcination is carried out at a temperature higher than 400"C. some changes will be brought about in a part of sepiolite owing to fusion and the like and the amount of the catalytic metal such as Co and Ni, supported by the ion-exchange method, may be decreased.

It is to be noted that the pore volume contracts in the course of the metal-supporting step.

The present inventors have found that this phenomenon of contraction takes place in a relatively low degree in the pores smaller than several hundreds in diameter, but is markedly exhibited in the pores in the range of several hundreds to several thousands A in diameter.

Therefore, by utilizing such phenomena advantageously, an excellent catalyst having high activity can be prepared.

For example, a catalyst having a high proportion of large pores several hundreds to several thousands A in diameter posesses a large pore volume but a small packing density; accordingly, the specific surface area per packing volume becomes smaller. In accordance with researches made by the present inventors, such catalyst posesses a longer lifetime, especially in hydrotreating heavy oils, since clogging of pores owing to deposition of metals and the like is much reduced, but its activity is lowered; therefore, it is necessary to make the proportion of large pores as small as possible by controlling the pore volume to such an extent that clogging of pores can be regulated.

When a heavy oil having a large metal content as much as 500 ppm by wt. to 1,000 ppm by wt. is treated mainly for the purpose of demetallization, it is desirable to employ a catalyst having a high proportion of large pores. However for the hydrotreatment of heavy oils with lower metal contents, a treated oil containing very small amounts of metal and sulfur can be obtained by using a catalyst with higher activity in which the ratio of large pores is reduced.

When it is intended to prepare a catalyst having a relatively high proportion of large pores for treating heavy oils containing a very large amount of metals, such catalyst can be obtained by selecting the conditions of kneading and moisture conditioning in such a way as to spread the pore distribution towards larger pores, although some of the large pores may be eliminated by means of the treatment with acids or ammonium salts, or the metal (Co, Ni, etc.) - supporting treatment.

Alternatively, the above-mentioned method can be carried out in the reverse order, that is, in the order of the metal-sup orting step and the subsequent kneading, molding and drying or heating (or calcination) step. According to this method, a metal on sepiolitematerial is incorporated with water, the resultant mixture is subjected to kneading or mastication, and then the water content thereof is adjusted, followed if desired by molding; whereby it is possible to recover the pore volume and specific surface area which were reduced in the course of ion-exchange treatment. Thus, a catalyst having a large pore volume and specific surface area can be obtained. A catalyst having a larger pore volume and specific surface area can be obtained by selecting suitable conditions of these treatments. Air-drying, calcination or sintering is carried out after the kneading or molding step at a temperature below 1,000 C.

As described above, by treating sepiolite in accordance with the suitable and selected combination of the metal-supporting, kneading, molding, calcination and/or pretreatment, there can be obtained a catalyst which is very effective for hydrotreating hydrocarbons and especially for demetallization, desulfurization and denitrification.

In addition, a catalyst having an excellent demetallization activity can be obtained by simply mixing the catalyst of the present invention with a used catalyst containing one or more metallic compounds of which metal or metals are selected from the transition metals and the IIb group metals of the periodic table. In this case, if so desired, the used catalyst may be ground and sepiolite may be subjected to grinding, moisture conditioning, molding or the pretreatment.

Of course, the metal on sepiolite-catalyst of the present invention has an excellent demetallization activity. A demetallization activity can be exhibited by employing a mixture of the catalyst of the present invention and a conventional catalyst for hydrogenation, or the catalyst comprising metal or metals supported on a mixture of sepiolite and a conventional carrier material. When the sepiolite is added to a conventional carrier material and mixed to provide the resulting catalyst with demetallization activity, the amount of sepiolite in the mixture is generally more than 5 % by weight for enhancing the demetallization activity of the resulting catalyst to some extent, and more than 20 % by weight for obtaining an excellent demetallization activity. Therefore, it is to be noted that a catalyst comprising the metal or metals supported on a mixture of sepiolite and the other carrier material is also included in the scope of the present invention.

Incidentally, it is to be noted that as a result of concomitantly employing sepiolite and other conventional carrier material as described above, the activity and lifetime of the resulting catalyst are enhanced as well as the cost of carrier is lowered in comparison with those of the conventional carrier, since sepiolite has a large pore volume and is available at a lower price than some of the conventional carrier materials.

The catalyst of the present invention can be employed in a very wide variety of hydrotreating reactions and for a very wide range of hydrocarbons. The catalyst is very useful for desulfurization, denitrification and hydrogenation of light oils such as gasoline and kerosine, and also for demetallization, deasphalting, desulfurization, denitrification, hydrogenation and hydrocracking of heavy oils such as vacuum gas oils, tar sands and bitumens.

Since the catalyst of the present invention is effective for various hydrotreating methods and a very wide range of hydrocarbons, a broad range of reaction conditions can be employed. But, the partial pressure of hydrogen is generally in the range of 10 to 350 atmospheres and preferably 15 to 300 atmospheres and the reaction temperature is generally in the range of 200 to 470"C and preferably 200"C to 450"C. These reaction conditions can be optionally selected according to the properties of hydrocarbons, the purpose of hydrotreating, the method of reaction and the like. In the same way, a conventional method of reaction can be employed in the present invention. For example, a conventional flow-type fixed bed, moving bed or fluidized bed reactor can be advantageously employed.

The metal on sepiolite-catalyst of the present invention is characterized in that the demetallization is selectively enhanced by hydrotreating hydrocarbons under the condition of a high partial pressure of hydrogen sulfide. When hydrocarbons are hydrotreated in the presence of a conventional catalyst for desulfurization, it is known that in the atmosphere of high partial pressure of hydrogen sulfide, the catalyst is poisoned by the hydrogen sulfide to gradually decrease the desulfurization activity of the catalyst. It is also known that demetallization is accordingly lowered as the desulfurization activity is lowered. Contrary to the conventional technical knowledge, the demetallization activity of the metal on sepiolite-catalyst is markedly enhanced as the treating time elapses in a reaction system having a substantial pressure of hydrogen sulfide, although its desulfurization is gradually lowered. Accordingly, the proportion of demetallization to desulfurization becomes gradually larger as the reaction time passes, and as a result a selective demetallization reaction takes place. In this case, the reaction is effectively carried out under a partial hydrogen pressure of more than 10 kg/cm2 and preferably more than 30 kg/cm By utilizing such unique properties of the metal on sepiolite-catalyst of the present invention, an efficient desulfurization process can be carried out combining two reaction steps, one being under a high partial pressure of hydrogen sulfide and the other being under a rather low partial pressure thereof.

The reaction process comprises the first step in which a selective demetallization of hydrocarbon is carried out under a high partial pressure of hydrogen sulfide followed by removing hydrogen sulfide gas dissolved in the hydrocarbons thus treated and the subsequent second step in which desulfurization of the resulting hydrocarbons is carried out under rather low partial pressure of hydrogen sulfide. Thus, in the second step, a rapid decrease in catalyst activity owing to deposition of metal on the catalyst is avoided, and the activities of the catalyst can be advantageously and fully utilized. Incidentially, the hydrogen sulfide gas which was generated in the second step can be recovered together with hydrogen gas and recycled to the first step for reuse. The hydrotreating conditions in the first and second steps are determined according to the kind of the hydrocarbon to be treated. The same conditions may be applied to both steps, and the reactions are generally carried out under hydrogen pressure of 10 to 350 kg/cm2 and at a temperature of 300 to 500"C.

The present invention will be further explained by way of the following Examples. The percentage (%) and ratio (ppm) employed in the Examples are based on weight unless otherwise specified.

Examples 1 to 7 As the starting material there was employed the sepiolite mineral of Spanish origin having a specific surface area of 170 m2/g, a pore volume of 0.59 cc/g, and a pore ratio of 25 % in the range of 200 to 400 in pore diameter (that is, the pores in the sepiolite, 200 to 400 in pore diameter, accounting for 25 % of the pore volume). The sepiolite was dried at 200"C for 3 hours, and ground in a ball mill until all of it attained fineness of 50 mesh or more, more than about 70 % of it having fineness of more than 100 mesh. The dried sepiolite powder was incorporated with an aluminium hydroxide sol containing 17 % of anhydrous alumina in such an amount as to make the ratio of anhydrous alumina to dry sepiolite 5 %, and the water content of the mixture was adjusted to 150 % by adding water thereto. The resulting moist mixture was well kneaded by an extruder. The number of passes through the extruder for kneading was that which, experimentally, gave the maximum pore volume after calcination at 500"C.

According to observation on photomicrographs (magnification x 10,000) by electron microscope of the kneaded mixture, it was confirmed that the fascicles of sepiolite fibers were untied to separate fibers in the case where the kneaded mixture had the maximum pore volume.

The kneaded mixture was molded into cylindrical pellets about 1.0 mm in diameter by a conventional extruder, which were air-dried and then calcined at 500"C for 3 hours to obtain porous sepiolite carriers.

The carriers were subjected to a conventional one-liquid or two-liquid treatment to have Cu, Zn, Ce, V, Mo, Ni and/or Co components supported on the carriers by utilizing ammonium metavanadate for V, ammonium paramolybdate for Mo and the corresponding nitrates for the other metals. The carriers thus treated were calcined at 500"C for 1 hour to obtain the catalysts shown in Table 1. Each of these catalysts had a specific surface area (BET method) of 180 to 210 m2/g, pore volume of 0.75 to 0.8 cc/g, and pore volume ratio of 40 to 55 % in the range of 200 to 400A in pore diameter.

Each of these catalysts was packed in a high pressure flow-type reactor. A topped residual oil containing 2.87 % of sulfur content, 3,600 ppm of nitrogen content, 3.0 % of n-heptane-insoluble matter, 150 ppm of vanadium, 41 ppm of nickel, and 3 ppm of iron, was subjected to hydrotreating using the reactor at hydrogen pressure of 140 kg/cm2, a reaction temperature of 400"C and a liquid space velocity of 2.0 Hr-l, with upward flow.

The results are shown in Table 1.

From these results, it is clearly shown that the catalyst of the present invention has a very high activity and that the residual oil containing a large amount of metals can be treated over a long period of time according to the method of the present invention.

TABLE 1 Example Catalytic metal composi- Activity of catalyst tion after 50 hours after 500 hours (1) (2) (3) (4) (1) (2) Nos. component %(as metal) DSR DVR DNR DAR DSR DVR 1 Cu 2 13 42 < 10 21 9 35 Mo 6 2 Cu 12 11 32 10 24 10 29 Zn 12 3 Ce 2 17 51 12 27 15 40 Mo 6 4 Ni 2 14 47 14 27 12 36 V 6 Co 3.5 5 Ni 1.0 29 68 15 35 21 58 Mo 7.5 Ni 2.6 6 Co 1.2 31 65 17 34 26 59 Mo 15.0 7 Co 1.5 37 70 19 42 24 62 Mo 4.8 Note: (1) DSR: desulfurization ratio % (2) DVR: devanadiuming (removal of vanadium) ratio % (3) DNR: denitrification ratio % (4) DAR: deasphaltening (removal of asphaltene) ratio % Example 8 A porous magnesia-silica carrier was prepared in the same way as in Examples 1 to 7 except that aluminium sulfate instead of aluminium hydroxide sol was added to dry sepiolite in such an amount as to make the ratio of anhydrous alumina to the sepiolite 2.0 %, water was added to the mixture to adjust the water content thereof to 135 %, and the molded pellets were calcined at 800"C for 3 hours.

The catalyst of the present invention was obtained by treating the resultant carrier with cobalt nitrate and paramolybdic acid according to a conventional method, to have 2 % of cobalt and 6 % of molybdenum supported on the carrier.

By employing the resultant catalyst, the same residual oil as used in Examples 1 to 7 was subjected to hydrotreating, at hydrogen pressure of 110 kg/cm2, reaction temperature of 370"C, and liquid space velocity of 0.8 Hr-1. Activity of the catalyst 50 hours after starting the reaction was measured, which is shown in the following: devanadiuming ratio : 61 % denickeling (removal of nickel) ratio : 48 % deironing (removal of iron) ratio : 64 % desulfurization ratio : 24 % Example 9 A porous magnesia-silica carrier was obtained in the same way as in Examples 1 to 7 except that aluminium hydroxide sol was added to dry sepiolite in such an amount as to make the ratio of anhydrous alumina to dry sepiolite 3.0 %, copper nitrate was further added thereto in such an amount as to make the ratio of copper to sepiolite 4 %, water was added to the mixture to adjust the water content thereof to 145 %, the kneaded mixture was molded into cylindrical pellet of 1.5 mm in diameter, and calcining was carried out at 4000C for 3 hours.

The resultant carrier was treated with an aqueous solution of ammonium paramolybdate according to a conventional method to have 6 % of molybdenum supported on the carrier.

The carrier thus treated was then calcined at 600"C for 1 hour to obtain a catalyst of the present invention.

By employing the resultant catalyst, the same residual oil as used in Examples 1 to 7 was subjected to hydrotreating, at hydrogen pressure of 140 kg/cm2, reaction temperature of 400"C, and liquid space velocity of 0.5 Hr-l. Activities of the catalyst 50 hours and 1,000 hours after starting the reaction are shown in the following. after 50 hours after 1,000 hours devanadiuming ratio (%) 97 88 denickeling ratio (%) 88 75 deironing ratio (%) 98 or more 91 desulfurization ratio (%) 74 57 denitrification ratio (%) 57 32 Example 10 The catalyst of the present invention was prepared in the same way as in Examples 1 to 7 except that cobalt nitrate instead of the aluminium hydroxide sol was added to dry sepiolite in such an amount as to make the ratio of cobalt to sepiolite 3.0 % followed by addition of water to adjust the water content thereof to 120 %, ammonium paramolybdate was added to the moist mixture in such an amount as to make the ratio of molybdenum to sepiolite 9 % followed by kneading and molding the mixture into pellets (instead of adding the catalytic metals to the molded carrier), and calcining was carried out at 5000C for 3 hours. The resultant porous magnesia-silica catalyst containing cobalt and molybdenum had the following physical properties: specific surface area (BET method) 216 m2/g pore volume ( > 74 ) 0.522 cc/g pore ratio (200 - 400A in diameter) 76 % By employing this catalyst, the same residual oil as used in Examples 1 to 7 was subjected to hydrogenation treatment, at hydrogen pressure of 140 kg/m2, a reaction temperature of 370"C and a liquid space velocity of 0.8 Hr-l. Activity of the catalyst 50 hours after starting the reaction is shown in the following. devanadiuming ratio 53 % denickeling ratio 40 % desulfurization ratio 19 % Example 11 A porous magnesia-silica carrier was obtained in the same way as in Examples 1 to 7 except that, in the course of the moistening step, acetic acid was added together with aluminium hydroxide sol and water to dry sepiolite to adjust the pH of the mixture to 4.0.

The resultant carrier was treated with aqueous solutions of nickel nitrate, cobalt nitrate and ammonium paramolybdate according to a conventional impregnating process, to have cobalt, nickel and molybdenum supported on the carrier. The treated carrier was sintered at 600"C for 1 hour to obtain a catalyst of the present invention. The properties of the catalyst are shown in the following. amounts of metals supported (as metal) Ni 2.4 % Co 1.5 % Mo 14.5 % specific surface area (BET method) 226 m2/g pore volume ( > 74 ) 0.62 cc/g pore ratio (200 - 400A in diameter) 66 % By employing this catalyst, the same residual oil as used in Examples 1 to 7 was subjected to hydrotreating, at hydrogen pressure of 140 kg/cm2, reaction temperature of 400"C, and liquid space velocity - of 2.0 Hr-1. The results are shown in the followings: after starting the reaction 50 hours 500 hours devanadiuming ratio % 75 63 denickeling ratio % 61 43 desulfurization ratio % 33 21 denitrification ratio % 16 12 Example 12 A porous magnesia-silica carrier was obtained in the same way as in Examples 1 to 7 except that, in the course of the moistening step, acid clay containing 60% of SiO2 and 15% of Al203 was added to the dry sepiolite in place of aluminum hydroxide sol in such an amount as to make the ratio of acid clay to sepiolite 5%, water was added thereto to adjust the water content to 160%, and the moist mixture was molded into cylindrical pellets 1.5 mm in diameter followed by calcining at 4000C for 3 hours.

The resultant carrier was treated with aqueo and molybdenum supported on a conventional alumina carrier or the catalyst which was prepared by having cobalt, nickel and molybdenum supported on untreated sepiolite mineral of 6 to 20 mesh in fineness.

Reference Examples 1 to 3 The conventional desulfurization catalysts (I) and (II) were prepared by having 3 or 3.5 % (hereinafter as metal) of cobalt and 8 or 10 % of molybdenum supported on alumina carrier. The other catalyst was prepared by having 3.5 % of cobalt, 1.1 % of nickel and 7.2 % of molybdenum supported on the untreated sepiolite having a specific surface area (BET method) of 154 m2/g and pore volume ( > 74 A) of 0.52 cc/g.

By employing these catalysts, the same residual oil as used in Examples 1 to 7 was subjected to hydrotreating, at hydrogen pressure of 140 kg/cm2, reaction temperature of 400"C and liquid space velocity of 2.0 Hr-1, with upward- flow. The results are shown in Table 2.

From these results, it is clearly shown that the catalysts according to the present invention have a markedly large demetallization (removal of metals) activity and a longer life of catalytic activity.

When compared with the untreated sepiolite carrier, the catalyst of the present invention has a larger demetallization activity even when the amounts and kinds of the catalytic metals are identical. Also in comparison with the physical properties of these catalysts, the present catalysts have a markedly larger specific surface area and pore volume.

TABLE 2 After starting the treatment 50 hours 500 hours 1,000 hours Reference Catalyst Example Nos. employed DVR* DSR** DVR* DSR** DVR* DSR** 9 desulfurization 64 75 40 46 13 22 catalyst (I) 10 desulfurization 69 73 58 55 29 35 catalyst (II) 11 catalyst with 73 32 70 29 62 22 sepiolite * DVR;devanadiuming ratio % ** DSR;desulfurization ratio % Example 13 A crushed sepiolite of Spanish product 1 to 2 mm in diameter was employed as the starting material. The sepiolite was dried at 2000C for 3 hours and then subjected to dry milling in a ball mill to such an extent that finely divided powder of 100 mesh or more was obtained in an amount of about 70 % of the whole powder, the coarse powder of larger than 50 mesh being sieved off.

Aluminium hydroxide sol containing 17 % of alumina was added to the sepiolite powder in such an amount as to make the ratio of alumina content to dry sepiolite 5 % and then water was added thereto to adjust the water content thereof to about 150 %, to obtain rather hard paste. The paste was fully kneaded by passing it through an extruder three times, followed by molding it into cylindrical pellets 1.0 mm in diameter by the extruder.

The pellets were air-dried and then calcined at 5000C for 3 hours to obtain molded product.

The properties of the resultant product are shown in Table 3 in comparison with those of the starting material sepiolite (dried at 2000C).

TABLE 3 molded starting sepiolite material (1) specific surface area 216 170* (BET method, m2/g) specific surface area > 74 A 113 71 (m2/g) distribution thereof 74 - 200 A 33 29 200 - 600 A 73 31 > 600 A 7 11 (2) pore volume > 74 A (cc/g) 0.83 0.59 distribution thereof 74 - 200 A 0.13 0.11 200 - 600 A 0.62 0.27 > 600 A 0.08 0.21 3 crushing strength (kg) 1.2 - 1.8 - 4 soaking in an aqueous homogeneous unhomogeneous solution of cobalt coloring coloring nitrate * calcined at 500"C for the purpose of the comparison with the molded sepiolite.

Incidentally, the difference in coloring after impregnating in an aqueous solution of cobalt nitrate (4) in Table 3 is due to the difference in homogenity of the cobalt supported on the sepiolite, which indicates that cobalt was homogeneously supported on the molded sepiolite.

Example 14 A molded sepiolite was obtained in the same way as in Example 13 except that, in the course of moistening step, the aluminium hydroxide sol was added to the sepiolite powder in such an amount as to make the ratio of anhydrous alumina to dry sepiolite 1.5 % and an aqueous nitric acid solution containing 0.1 mol/1 of nitric acid was added thereto instead of pure water to adjust the water content thereof to 120 %. The calcined product had the following properties.

(1) specific surface area (BET method) 250 m2/g 2 pore volume > 74 A 0.58 cc/g As to the distribution of pore, most of large pores 600 A or more in diameter disappeared; and the pores 200 to 400 A in diameter accounted for about 70 % of the whole pore volume.

(3) crushing strength 4.6 - 6.0 kg The molded product obtained in this Example was subjected to X-ray diffraction analysis, the pattern of which clearly showed a peak in the neighborhood of 2 0 = 7 , and it was assured that the molded product of this invention was converted to thermally stable forms.

Example 15 A molded product was prepared in the same way as in Example 13 except that aluminium nitrate instead of the aluminium hydroxide sol was added to the sepiolite powder in such an amount as to make the ratio of aluminium metal to dry sepiolite 3.0 %, water content was adjusted to 130 %, and sintering was carried out at 8000C. The sintered product had the following properties.

(1) specific surface area (BET method) 237 m2/g (2) pore volume > 74 A 0.49 cc/g (3) crushing strength 4.7 - 7.5 kg From these results, it is evident that the molded product has a rather smaller pore volume, but has a larger specific surface area and markedly larger crushing strength.

Examples 16 to 18 Molded products were obtained in the same way as in Example 13 except that, in the course of moistening step, the aluminium hydroxide sol was added to the sepiolite powder in such an amount as to make the ratio of anhydrous alumina to dry sepiolite 1.5 %, an aqueous solution of copper nitrate, cerium chloride or nickel sulfate was added thereto instead of pure water in an amount of 2 % as Cu, Ce or Ni on the basis of dry sepiolite, respectively, and the water content thereof was adjusted to 130 %. The sintered products had the following properties as shown in Table 4.

TABLE 4 Example Nos.

61 62 63 (1) additives (metal salts) Cu (NO3)2 CeCl3 NiSO4 (2) specific surface area 241 249 232 (BET method, m2/g (3) pore volume ( > 74 , cc/g) 0.55 0.57 0.58 (4) crushing strength (kg) 5.0-6.5 4.7-6.0 3-5.0 Measurement of the pore distribution clearly showed that most of the large pores of more than 600 in diameter disappeared in these molded products and the pores in the range of 200 to 400 A in diameter accounted for 70 to 80 % of the whole pore volume and had a very sharp distribution curve. The X-ray diffraction patterns showed that the products were thermally stable since the peaks in the neighborhood of 2 0 = 7" were scarcely lowered.

Example 19 A molded product was obtained in the same way as in Example 13 except that cobalt nitrate was added to the sepiolite powder in such an amount as to make the ratio of cobalt metal to dry sepiolite 3.0 %, pure water was added thereto to adjust the water content thereof to 120 %, and then ammonium molybdate was further added thereto in such an amount as to make the ratio of molybdenum metal to dry sepiolite about 9 %. The calcined product had the following properties.

(1) specific surface area (BET method) 216 m2/g (2) pore volume ( > 74 ) 0.52 cc/g (3) pore distribution (ratio in the 76 % range of 200 to 400 ) (4) crushing strength 3.0 - 4.5 kg Example 20 Sepiolite of Korean product was crushed to the fineness 4 to 5 mm in diameter to be employed as the starting material. The crushed sepiolite was impregnated for two days and nights in an aqueous solution containing 0.1 mol/1 of nickel nitrate and then throughly washed with warm water maintained at 500C. Incidentally, the resultant nickel on sepiolite was calcined at 5000C for 2 hours and the analysis thereof showed that 2.1 % of nickel oxide was contained therein. According to the analysis of the aqueous nickel nitrate solution in which sepiolite was soaked, magnesium was dissolved therein in an amount about 2.6 times (atomic ratio) as much as that of nickel supported on sepiolite.

About 3 parts of water was added to one part of the original uncalcined nickel-on sepiolite-material, and the resultant mixture was well kneaded by a kneader. Through this kneading step, the crushed sepiolite was ground to powder. After the mixture was kneaded enough to render it moldable, the kneaded mixture was dried at 600C for a short time, followed by addition of water to adjust the water content thereof to about 130 %. The moist mixture was kneaded again for such a short time that the water content did not change, and then molded into cylindrical pellets 1.7 mm in diameter. The molded pellets were air-dried for about 5 days and then calcined at 5000C for 1 hour to obtain a nickel on sepiolite-catalyst. The physical properties of the resultant catalyst as well as those of the starting sepiolite which was calcined at 5000C for 1 hour are shown in Table 5.

TABLE 5 nickel on sepio- starting material lite-catalyst sepiolite (calcined at (calcined at 5000C) 500"C) specific surface area (BET method) 232 m2/g 153 specific surface area (mercury porosimeter method > 30 ) 133 m2/g 65 pore volume (mercuryoro- simeter method > 30 Ii) 0.68 cc/g 0.52 pore distribution (mercury porosimeter method > 30 ) 30 - 200 A 0.19 cc/g 0.12 200 - 600 A 0.44 cc/g 0.20 600 A 0.05 cc/g 0.18 crushing strength 3.5 - (radical direction) - 5.0 kg From Table 5, it will be understood that the nickel on sepiolite molded catalyst obtained according to the present invention has the physical properties significantly different from those of the starting material se iolite. That is, the molded product of the invention has (1) a larger specific surface area, (2) a large pore volume, and (3) a sharper distribution curve, in comparison with the starting material sepiolite. The nickel on sepiolite molded product is clearly different in property from the product obtained by merely having nickel supported on the starting material sepiolite. Thus, it would be understood that the treatment procedure for sepiolite according to the present invention is quite different from a mere molding procedure (conventional carriers).

A cracked petroleum oil (boiling point: 200 - 500"C) containing 2.4 % of sulfur and 14 ppm of vanadium and having bromine number 26 was subjected to hydrotreating by employing this catalyst. Reaction was carried out by using a conventional flow-type high pressure reactor at a reaction temperature of 360"C, hydrogen partial pressure of 50 kg/cm2 and liquid space velocity of 1.0 Hr-l. The analysis of the treated oil 50 hours after starting the reaction showed the decreases in sulfur to 2.1 %, vanadium to 5 ppm and bromine number to 16.

Example 21 The uncalcined nickel-on-sepiolite molded catalyst which had been obtained in Example 20 was air-dried and then baked at 2000C for 1 hour. The baked product was impregnated in an aqueous ammonium solution of ammonium paramolybdate and then calcined at 500"C for 1 hour, to obtain a nickel and molybdenum on sepiolite-catalyst. The analysis of the resultant catalyst showed that 2.0 % of NiO and 4 % of MoO3 were contained therein. The physical properties of the catalyst measured in the same way as in Example 65 were similar to those of the catalyst obtained in Example 65, except that the specific surface area (BET method) and pore volume were slightly decreased to 226 m2/g and 0.66 cc/g, respectively.

The same cracked petroleum oil as used in Example 20 was subjected to hydrotreating using the same apparatus under the same conditions as in Example 20, by employing the resultant catalyst. (That is, Example 20 was repeated by employing this catalyst). The analysis of the treated oil showed the decreases in sulfur to 0.89 %, vanadium to 3 ppm and bromine number to 14.

Example 22 In the kneading step of the unformed (not molded) nickel on sepiolite-material in Example 20, a predetermined amount of ammonium paratungstate was added thereto, to prepare a nickel and tungsten on sepiolite-catalyst. The kneading, moistening, molding and calcining steps were carried out in the way and under the conditions similar to those of Example 20. The analysis of the resultant catalyst showed that 2.0 % of NiO and 7.8 % of WO3 were contained therein. The physical properties of the catalyst were similar to those of the catalyst obtained in Example 20, as in the case of Example 19.

By employing this catalyst, a topped residual oil containing 2.62 % of sulfur, 3,600 ppm of nitrogen, 3.2 % of n-heptane-insoluble matter, 130 ppm of vanadium, and 41 ppm of nickel was subjected to hydrotreating using the same reaction apparatus as in Example 20.

The reaction was carried out at reactive hydrogen pressure of 140 kg/cm2, reaction temperature of 420"C and liquid space velocity of 0.5 Hr~l. The analysis of the treated oil showed the following results. Sulfur: o.31 %; Nitrogen: 2,100 ppm; n-heptane-insoluble matter: 0.3 %; Vanadium: 2 ppm; and Nickel: 3 ppm.

Example 23 A copper and molybdenum on sepiolite-catalyst was prepared in a similar way to Example 20.

A sepiolite of Spanish product was crushed to the particle size of 1-2 mm in diameter and impregnated for a whole day and night in the aqueous solution containing 0.1 mol/1 of magnesium nitrate, followed by sufficient washing with warm water. The treated sepiolite was impregnated in the aqueous solution containing 0.02 mol/1 of copper nitrate, and rinsed with warm water and then with 5 % ammonia water, followed by drying at 1200C for 2 hours. To the dried sepiolite, were added 3 % (based on anhydrous alumina) of an aluminium hydroxide sol containing 16 % of alumina, 25 % of attapulgite clay of the U.S. product and 200 % of water, followed by wet milling for about 10 hours. An aqueous ammonium solution of ammonium paramolybdate was then added thereto and the mixture was sufficiently kneaded, followed by repeating drying (at 600C) and water spray to adjust the water content thereof to 210 %. The moist mixture was molded into cylindrical pellets 1.7 mm in diameter, which was then dried for about a week and calcined at 500"C for two hours. Thus, a copper and molybdenum on sepiolite-catalyst was obtained. The analysis of the resultant catalyst showed that 2.4 % of CuO and 6.4 % of MoO3 were contained therein. The physical properties of the catalyst measured in the same way as in Example 20 are shown in Table 6.

TABLE 6 Properties of copper and molybdenum on sepiolite-catalyst specific surface area (BET method) 210 m2/g specific surface area mercury porosimeter method, > 30 A) 107 m2/g pore volume (mercurporosi- meter method, > 30 ) 0.74 cc/g pore distribution (mercury porosimeter method) 30 - 200 A 0.13 cc/g 200 - 600 A 0.35 cc/g > 600 A 0.26 cc/g crushing strength (radial direction) 2.2 - 4.7 kg Example 22 was repeated to carry out hydrotreating by employing this catalyst. The analysis of the treated oil 50 hours after starting the reaction showed the following results.

Sulfur: 0.28 5k, Nitrogen: 2,200 ppm; Vanadium: 2 ppm; and Nickel: 62 ppm.

Example 24 A cerium and molybdenum on sepiolite-catalyst was prepared in a similar way to Example 23. Crushed sepiolite of Spanish product was impregnated with stirring in the aqueous solution containing 0.01 mol/1 of nitric acid and 0.1 mol/1 of magnesium nitrate for 5 hours. The treated sepiolite was further impregnated in the aqueous solution containing 0.1 mol/1 of cerium nitrate for 5 hours to obtain a cerium on sepiolite-material. After the cerium on sepiolite-material was sufficiently washed with warm water, thereto were added, on the basis of sepiolite, 5 % (as anhydrous alumina) of aluminium hydroxide sol containing 16 % of alumina. 25 % of bauxite containing 1.8 % of TiO2 and 5.1 % of Fe203, and about 150 % of water, followed by subjecting the mixture to wet milling for 10 hours. An aqueous ammonium solution of ammonium paramolybdate was added to the ground mixture and then sufficiently kneaded, followed by adjusting the water content thereof to 125 %. The moist mixture was molded into cylindrical pellets 1.0 mm in diameter, which were air-dried for about one week and then calcined at 6500C for 2 hours. Thus, a cerium and molybdenum on sepiolite-catalyst was obtained. The analysis of the catalyst showed that 1.2 % of Ce203 and 3.1 % of MoO3 were contained therein. The physical properties of the catalyst were measured to be 146 m2/g in specific surface area and 0.57 cc/g in pore volume (mercury porosimeter method, diameter B30 ).

Example 22 was repeated to carry out hydrotreating by employing this catalyst. The treated oil 50 hours after starting the reaction contained 0.45 % of sulfur and < 2 ppm of vanadium.

Examples 25 to 27 A hydrogenation catalyst for treating hydrocarbons was prepared from a sepiolite of Spanish product. The crushed sepiolite having particle sizes of 1 to 2 mm in diameter was ground to 50 mesh pass, and water was added thereto followed by thorough kneading by a kneaded. In the course of the kneading, 5.0 % (as anhydrous alumina) of aluminium hydroxide sol containing 20 % of alumina was added thereto and the mixture was further kneaded to mix it up. By spraying water onto the kneaded mixture, it was homogeneously moistened to adjust the water content thereof to 200 % and then molded into cylindrical pellets 1.0 mm in diameter by an extruder. The molded pellets were air-dried at room temperature for about a whole day and night and further dried at 1200C for 3 hours. The resultant molded sepiolite product which had been calcined at 5000C for 1 hour had a pore volume (mercury porosimeter method, > 30 ) of 0.92 cc/g and a specific surface area (BET method by means of N2 adsorption) of 171 m2/g.

The molded sepiolite product dried at 1200C was impregnated in 5 times by volume of an aqueous acidic solution containing 0.1 mogul of cobalt nitrate, copper nitrate or lanthanum nitrate for about two days and nights and taken out, followed by washing it thoroughly with warm water at 45 to 50 "C. Incidentally, it was observed that magnesium was dissolved in the acidic aqueous solution. The washing with warm water was repeated until a metal ion such as Co iron was scarcely observed in the waste washing water. The resultant metal on sepiolite molded product was baked at 200"C for about 2 hours, and was further calcined at 500"C for 1 hour to obtain a calcined product. The measurement of the physical properties thereof according to mercury porosimeter showed that it had a pore volume in the range of 0.75 - 0.80 cc/g and a specific surface area of 115 - 120 m2/g ( > 30 ), irrespective of the kind of the metals supported. The color of Co or Cu on sepiolite molded product scarcely changed when baked at 200 or 5000C and was substantially the same as that of a sepiolite molded product which did not support the metal thereon.

Onto the Co, Cu, or La on sepiolite molded product, an aqueous solution containing a predetermined amount of ammonium paramolybdate and about 7 % of ammonia was sprayed to impregnate it with about 6 % (as MoO3) of molybdenum. The impregnated product was dried at 1200C for about 3 hours and then calcined at 5000C for about 1 hour to obtain a Mo and Co, Cu or La on sepiolite-catalyst.

The physical properties of the resultant catalysts as well as the amounts of the metals supported are shown in Table 7.

TABLE 7 Examples Reference 25 26 27 Example * Amount of metals supported CoO, CuO, Lea203(%) CoO; CuO; Lea203; 1.8 2.3 1.1 0 MoO3 (%) 6.1 5.6 6.2 0 specific surface area 147 134 155 171 (BET method) (m2/g) pore volume ( > 30 A)**(cc/g) 0.77 0.72 0.76 0.92 pore distribution** 30 - 100 A (cc/g) 0.032 0.030 0.026 0.040 100 - 400 (cc/g) 0.451 0.455 0.466 0.472 > 400 A 0.290 0.232 0.270 0.409 * carrier without catalytic metal ** according to mercury porosimeter method From Table 7, it is shown that the pore volumes of the metals on sepiolite-catalysts obtained according to the present invention are smaller than that of the sepiolite carrier which was obtained by simply calcining the sepiolite molded product, but the percentage decrease in pore volume is larger for the larger pores, more than 400 A in diameter.

Incidentally, the pore volume of the starting material sepiolite which had been simply calcined at 5000C for 1 hour was 0.59 cc/g. Therefore, the pore volumes of the metals on sepiolite-catalysts according to the present invention are far larger than that of the starting material sepiolite and the percentage of large pores in the present catalysts is lowered in comparison with that of the simply calcined molded product; thus it is understood that the catalysts of the present invention have a very sharp pore distribution.

By employing each of these catalysts, a topped residual oil containing 2.62 % of sulfur, 3,600 ppm of nitrogen, 130 ppm of vanadium, 41 ppm of nickel and 3.0 % of asphaltene was subjected to hydrotreating. Reaction was carried out by using a conventional flow-type high pressure reactor at reaction temperature of 375"C, hydrogen pressure of 140 kg/cm2 and liquid space velocity of 0.5 Hr-1. The analysis of the treated oil 100 hours after starting the reaction showed the results given in the following Table 8.

TABLE 8 Impurities in the treated oil Example 25 Example 26 Example 27 sulfur (%) 1.15 1.03 1.38 nitrogen (ppm) 2,800 2,400 3,000 vanadium (ppm) 20 26 21 nickel (ppm) 11 9 10 asphaltene (%) 1.6 1.4 1.7 Example 28 The same sepiolite as employed in Examples 25 to 27 was impregnated in the aqueous solution containing 0.1 mol/1 of ammonium nitrate for a whole day and night, and then was well rinsed with warm water. The sepiolite was subjected to wet milling to obtain fine powder, and then 3 % (as alumina) of aluminium nitrate was added thereto followed by thorough kneading by a kneader. The kneaded mixture was repeatedly dried at 800C and sprayed with water to adjust the water content thereof to 120 %. The moist mixture was molded into cylindrical pellets 1.0 mm in diameter, which were air-dried and then further dried at 1200C. The method of Examples 25-27 was repeated to have copper and molybdenum supported on the dried pellets. The resultant pellets were calcined at 500"C for 1 hour to obtain a catalyst of the present invention. The properties of the catalyst are shown in Table 9.

TABLE 9 Amount of metals supported CuO : 2.0 % MoO3 : 6.3 % specific surface area 162 m2/g pore volume 0.61 cc/g pore distribution 30 - 100 A 0.058 cc/g 100 - 400 A 0.503 > 400 A 0.046 By employing this catalyst, a vacuum gas oil containing 2 % of sulfur is subjected to desulfurization at hydrogen pressure of 30 kg/cm2, reaction temperature of 380"C, and liquid space velocity of 1.0 Hr-l. The sulfur content in the treated oil was decreased to 0.29 % about 100 hours after starting the reaction.

Example 29 A Co and Mo on sepiolite-catalyst was prepared in a similar way to Example 28. To the sepiolite were added 20 % (as anhydride) of attapulgite of the U.S. product instead of aluminium nitrate, 3 % (as alumina) of the same aluminium hydroxide sol as employed in Examples 25 to 27, and 3 % of ammonium nitrate, followed by kneading. The kneaded mixture was moistened to adjust its water content to 125 % and molded into pellets, which were dried at 200"C for 1 hour. The method of Example 25 was repeated to have cobalt and molybdenum supported on the pellets, which were calcined at 5000C. The analysis of the resultant catalyst showed that 1.6 % of CoO and 6.0 % of MoO3 were contained therein.

The catalyst had a specific surface area of 159 m2/g according to BET method. Also it had a whole pore volume of 0.68 cc/g and a large pore volume ( > 400 ) of 0.102 cc/g, according to mercury porosimeter method.

By employing this catalyst, a solvent-deasphalted oil was subjected to hydrogenation treatment using the same reaction apparatus as used in Examples 25 to 27. The deasphalted oil containing 2.4 % of sulfur, 26 ppm of vanadium and 12 ppm of nickel was treated at a reaction temperature of 380"C, hydrogen pressure of 100 kg/cm2, and liquid space velocity of 1.0 Hr-l. The analysis of the treated oil 100 hours after starting the reaction showed the decreases in sulfur content to 1.22 %, vanadium to 5 ppm, and nickel to 4 ppm.

Examples 30 and 31 To the same crushed sepiolite as employed in Examples 25 to 27 were added and 20 % (as anhydride) of a bauxite containing 2.3 % (as TiO2) of titanium and 4.9 % (as Fe203) of iron, followed by wet milling by a ball mill. The ground mixture was subjected to levigation at 50 mesh and then 3 % (as alumina) of an aluminium hydroxide sol was added thereto with sufficient kneading. The kneaded mixture was calcined at 5000C until the pore volume thereof reached 0.82 cc/g, dried at 80"C, and homogeneously moisted to adjust the water content thereof to 120 Wo. The resultant moist mixture was molded into cylindrical pellets 1.5 mm in diameter, which were air-dried and then baked at 300"C for 2 hours. The calcined pellets were impregnated in the aqueous solution containing 0.02 mol/1 of nickel sulfate for about a whole day and night and then rinsed sufficiently with warm water. The resultant nickel - sepiolite-pellets were baked at 3000C for 2 hours, and then an aqueous ammonium solution (containing 5 % of ammonia) of a predetermined amount of vanadium oxalate or ammonium paratungstate was sprayed on the pellets to have vanadium or tungsten supported thereon. The sprayed pellets were calcined at 650"C for 2 hours to prepared a Ni and V on sepiolite- or Ni and W on sepiolite-catalyst. The physical properties and the amounts of the metals supported on these catalysts are shown in Table 10.

TABLE 10 Example 30 Example 31 amount of metals supported (Ni, V) (Ni, W) NiO 1.2 % 1.3 % V2Os or WO3 4.7 % 3.1 % specific surface area 155 m2/g 140 m2/g (BET method) pore volume ( > 30 ) o.61 cc/g 0.66 cc/g pore distribution 30 - 100 A 0.058 cc/g 0.062 cc/g 100 - 400 A 0.305 cc/g 0.343 cc/g > 400 A 0.246 cc/g 0.259 cc/g By employing each of these catalysts, hydrotreating was carried out by using the same

Claims

TABLE 12 amount of the metal supported CuO 2.8 % specific surface area 175 m2/g pore volume ( > 30 ) 0.48 cc/g pore distribution

30 - 100 A 0.027 cc/g

100 - 400 A 0.42 cc/g > 400 A 0.031 cc/g By employing this catalyst, the same topped residual oil as used Examples 25 to 27 was subjected to hydrotreating under the same conditions as in Examples 30 and 31. The treated oil 100 hours after starting the reaction contained the following impurities. sulfur 2.16 % vanadium 36 ppm nickel 25 ppm asphaltene 1.8 % WHAT WE CLAIM IS: 1. A catalyst for hydrotreating hydrocarbons which comprises an effective amount of one or more compounds of Cu, Ag, Au, Zn, Cd, Hg, Sc, Y, lanthanides, actinides, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Fe, Co, Ni, Ru, Rh, Pd, Os, Ir and/or Pt supported on sepiolite that has been treated by the successive steps of: (a) adding water thereto, (b) kneading the mixture and adjusting the water content thereof to from 20% to 350% by weight in either order), and (c) air-drying or heat-treating the mixture at a temperature less than 1000"C.
2. A catalyst according to claim 1, in which the one or more compounds supported on the sepiolite are compounds of Co, Ni, Fe, Cu, lanthanides, V, Cr, Mo and/or W.
3. A catalyst according to claim 1 in which the compounds supported on the sepiolite comprise both one or more compounds of Co, Ni, Fe, Cu and/or the lanthanides, and one or more compounds of Mo, W and/or V.
4. A catalyst according to any preceding claim which is shaped.
5. A method for the preparation of a catalyst according to any preceding claim, which comprises the steps of (i) adding water to natural sepiolite or to sepiolite that has been crushed or ground, (ii) kneading the mixture, (iii) adjusting the water content to from 20% to 350% by weight, (iv) air-drying or calcining the mixture at less than 1000"C, and (v) adding the one or more compounds to the sepiolite, the order of steps (i) to (iv) being (i), (ii), (iii), (iv) or (i), (iii), (ii , (iv), and the addition of the selected compounds (step (v)) being before, during or after steps (i) to (iv).
6. A method according to claim 5, wherein after the addition of the compound(s) to the sepiolite the mixture is heat-treated at a temperature less than 1000"C.
7. A method for the preparation of a catalyst according to any of claims 1 to 4, which comprises adding the one or more compounds to the sepiolite before the sepiolite has been kneaded.
8. A method according to any of claims 5 to 7, wherein the one or more compounds are added to the sepiolite in the form of aqueous acidic solution(s) containing one or more of the metal ions.
9. A method according to claim 8, wherein the aqueous acidic solution(s) contain ions of Co, Ni, Fe, Cu and/or lanthanides.
10. A method according to claim 8 or claim 9, in which the sepiolite after treatment with the metal ion-containing solution is subjected to a rinse treatment with a rinsing liquid.
11. A method according to claim 10, in which the rinsing liquid is water, a basic aqueous solution or an acidic aqueous solution.
12. A method according to any of claims 5 to 7, in which the one or more compounds are added to the sepiolite in the form of an aqueous ammonia and/or amine solution containing one or more of the metals which are Cu, V, Nb, Ta, Cr, Mo, W, Fe, Co, Ni, Ru, Rh, Pd, Os, Ir and Pt.
13. A method according to claim 12 in which the metals are selected from Mo, W and V.
14. A method according to any of claims 5 to 7, in which the one or more compounds are added to the sepiolite in a two-stage treatment comprising a first step of contacting the sepiolite with an acidic aqueous solution containing one or more metal ions, the metal(s) being selected from Cu, Ag, Au, Zn, Cd, Hg, Sc, Y, the lanthanides, the actinides, Fe, Co, Ni, Ru, Rh, Pd, Os, Ir and Pt, and a second step of contacting the resulting metal on sepiolite with an aqueous ammonia and/or amine solution containing one or more metal ions, the metal(s) being selected from Cu, V, Nb, Ta, Cr, Mo, W, Fe, Co, Ni, Ru, Rh, Pd, Os, Ir and Pt.
15. A method according to claim 14, in which in the first step the metal(s) are selected from Co, Ni, Fe, Cu and the lanthanides.
16. A method according to claim 14 or claim 15, in which in the second step the metal(s) are selected from Mo, W and V.
17. A method according to any of claims 14 to 16 in which the sepiolite treated in the first step is subjected to a rinse treatment with a rinsing liquid before the treated sepiolite is subjected to the second-step treatment.
18. A method according to claim 17, in which the rinsing liquid is water, a basic aqueous solution, or an acidic aqueous solution.
19. A method according to any of claims 5 to 18, in which the sepiolite is molded before or after the step of having the metal(s) supported on the sepiolite.
20. A method according to any of claims 5 to 19, in which one or more additives are added to the sepiolite during the moisture conditioning or kneading of step (b) so as to enhance the molding properties and molded part strength; said additives being selected from aluminium hydroxide sol, alumina silica sol, silica sol, other aluminium-containing substances, other silica-containing substances, bauxite, kaolin, montmorillonite, allophane, bentonite, attapulgite, other clay minerals, higher alcohols, esters of higher alcohols, ethers of higher alcohols, urea, starch, sucrose and organic molding auxiliaries.
21. A method according to any of claims 5 to 20, in which before or in the step of kneading, the sepiolite is treated with an aqueous solution containing one or more members selected from the group consisting of inorganic acids, organic acids, ammonium salts, salts of ammonium derivatives and magnesium salts.
22. A catalyst according to claim 1, substantially as disclosed in any of the Examples herein.
23. A method according to claim 5, substantially as disclosed in any of the Examples herein.
24. A method for the desulfurization, denitrification and/or demetallization of hydrocarbons, which comprises heating the hydrocarbons with pressurized hydrogen in the presence of a catalyst according to any of claims 1 to 4 and 22, or a catalyst obtained by a process according to any of claims 5 to 21.
25. A method according to claim 24, in which the hydrocarbons are treated under a hydrogen pressure of 10 to 350 kg/cm2 and at a temperature of 300 to 500"C.
26. A method according to claim 24 or claim 25, in which the hydrocarbons are treated in the presence of a partial pressure of hydrogen sulfide.