Title of Invention	A HYDROCRACKING CATALYST FOR PRODUCING MIDDLE DISTILLATES AND A PROCESS FOR THE PREPARATION OF THE SAME
Abstract	The present invention relates to a hydrocracking catalyst for producing middle distillates, comprising hydrogenation metal components, a modified ultra-hydrophobic zeolite-Y, a specific amorphous silica-alumina and optionally an alumina binder, wherein said zeolite-Y has a SiO2/AI<sub>2</sub>O<sub>3</sub>3) molar ratio of 5-25, a crystal unit cell size of 2.420-2. 445nm, an IR acidity of 0.2-0.6mmol/g, a sorptive capacity for water vapor of less than 5wt%/o at 25ºC and p/Po of 0.1, and a specific surface area of 600-850m2/g; and said amorphous silica-alumina has a SiO<sub>2</sub> content of 10wt%5wt%, a specific surface area of 300-600 m2/g, a pore volume of 0.8-1.5 ml/g and an IR acidity of 0.25-0.60mmol/g. The catalyst as claimed In the present Invention shows a relatively high activity and mid-distillate selectivity and can be used in hydrocracking process to give a higher yield of mid-distillates.

Title of Invention

A HYDROCRACKING CATALYST FOR PRODUCING MIDDLE DISTILLATES AND A PROCESS FOR THE PREPARATION OF THE SAME

Abstract

The present invention relates to a hydrocracking catalyst for producing middle distillates, comprising hydrogenation metal components, a modified ultra-hydrophobic zeolite-Y, a specific amorphous silica-alumina and optionally an alumina binder, wherein said zeolite-Y has a SiO2/AI2O33) molar ratio of 5-25, a crystal unit cell size of 2.420-2. 445nm, an IR acidity of 0.2-0.6mmol/g, a sorptive capacity for water vapor of less than 5wt%/o at 25ºC and p/Po of 0.1, and a specific surface area of 600-850m2/g; and said amorphous silica-alumina has a SiO2 content of 10wt%5wt%, a specific surface area of 300-600 m2/g, a pore volume of 0.8-1.5 ml/g and an IR acidity of 0.25-0.60mmol/g. The catalyst as claimed In the present Invention shows a relatively high activity and mid-distillate selectivity and can be used in hydrocracking process to give a higher yield of mid-distillates.

Full Text	FIELD OP THE INVENTION The present invention relates to a hydrocracking catalyst and a process for the preparation thereof, more particularly, to a catalyst for treating petroleum hydrocarbon materials to produce middle distillates and a process for the preparation thereof. BACKGROUND OF THE INVENTION Currently, since the refineries in the world have to face the problems that feedstocks become heavier and heavier and qualities of them worse and worse, the hydrocracking process has yet become an important means for lightening heavy oils. The hydrocracking catalyst is a dual-function catalyst possessing the properties of both hydrogenation and cracking. In general, a hydrocracking catalyst containing non-noble metals comprises Groups VIB and VIII metal components as the hydrogenation components, and a crystalline zeolite and/or amorphous silica-alumina as acidic components. Although an amorphous hydrocracking catalyst containing solely amorphous silica-alumina as an acidic component has a relatively high selectivity, its activity is low and operational flexibility limited. However, the application of zeolites in the preparation of hydrocracking catalyst has brought about a qualitative advancement of the hydrocracking technique, contributing to overcoming the defects of low activity and short running cycle in the hydrocracking catalysts containing amorphous silica-alumina as an active component and reducing significantly the reaction temperature of the catalyst. In particular, in order to increase the operational flexibility of the catalyst to meet the requirement for treating the steadily worse-quality feedstocks from the market, the mid-distillate type hydrocracking catalysts commonly used at present in the industry comprise amorphous silica-alumina in combination with zeolite component so as to fulfil the dual requirements of the catalyst for activity and mid-distillate selectivity. With respect to the mid-distillate type hydrocracking catalyst, in addition to the activity of the catalyst, the mid-distillate selectivity should be especially taken into consideration. The stronger acid sites of zeolite in relation to the acidic silica-alumina can enhance the cracking activity of the catalyst, but its strong cracking activity may result in noticeable decrease in the mid-distillate selectivity. Therefore, it needs to seek a better balance between the activity and the mid-distillate selectivity of the catalyst. In order to solve the contradiction between the reaction activity and the mid-distillate selectivity and according to the requirements for balanced matching of the acidic cracking function and the hydrogenation function of the mid-distillate type hydrocracking catalyst, it needs to develop new-type zeolites and amorphous silica-alumina materials and, through adjusting the ratio of the amorphous silica-alumina to zeolite component in the carrier, to achieve the final object of attaining an optimal level of both the desirable activity and selectivity in the course of reaction. US Patent No. 4,894,142 discloses a hydrocracking catalyst having an improved mid-distillate selectivity, comprising an amorphous silica-alumina and a low acidity zeolite-Y, wherein said zeolite-Y is characterized in that it has a TPD acidity of less than 2.0mmol/g, preferably 1.5mmol/g. In order to reduce the acidity, the main features of the process for the preparation of said zeolite lie in that the starting material zeolite is treated at a high temperature, including hydrothermally treated at 676~788°C, or dry-treated preferably at 704°C by introducing an inert gas. Since the zeolite has exceedingly low acidity, when a catalyst comprising said zeolite as component is used for treating the feedstock oils, the reaction temperature is over 410°C at the conversion of 85%. Such a high temperature inhibits the hydrogenation reaction while the thermal cracking performance of the zeolite increases, with the result that the mid-distillate selectivity of the catalyst is not obviously improved; specifically, the mid-distillate selectivity is less than 70%, indicating that a better balance has not been obtained for solving the contradiction between the activity and the mid-distillate selectivity as mentioned above. us Patent No. 4,517,074 discloses a hydrocracking catalyst for producing 300-700°F (149-371°C) middle distillates, wherein the feedstocks are preferably pretreated by hydro-denitrogenation and/or hydro-desulfurization. Said catalyst is characterized in that it comprises, in addition to a zeolite component, a dispersion system of SiO2-Al2O3 in a gamma alumina matrix containing 20-65% SiO2, in which, although the amorphous silica-alumina has a certain level of cracking activity, it has to be dispersed into an alumina matrix, such as large-pore Y -AI2O3 used as a component of the carrier, so as to obtain sufficient pore volume and specific surface area for supporting a large amount of metal components for hydrogenation. Although the catalyst has a relatively high mid-distillate selectivity of more than 80%, its activity is relatively low, thus, in order to achieve a conversion of 60vol%, the reaction temperature must generally be higher than 400°C. An example of the patent showed that by the use of a catalyst comprising silica-alumina of as high as 75% silica content dispersed in Y-AI2O3 in combination with a zeolite, such as zeolite LZ-10, the reaction temperature still need to be at 389°C. Therefore, there is still a need in the art to develop a hydrocracking catalyst having both good activity and high mid-distillate selectivity, and a process for the preparation thereof. After extensive studies and experiments, the inventors have discovered a hydrocracking catalyst comprising hydrogenation metal components, a modified zeolite-Y and a specific amorphous silica-alumina, which exhibits the desired properties, and a process for the preparation thereof. THE OBJECTS OF THE INVENTION The object of the present invention is to provide a hydrocracking catalyst, comprising hydrogenation metal components, a modified zeolite-Y and a specific amorphous silica-alumina, which has both good activity and high mid-distillate selectivity and is useful in treating heavy hydrocarbon materials to produce middle distillates. Another object of the present invention is to provide a process for the preparation of the catalyst of the present invention, comprising the steps of mixing a specific amorphous silica-alumina, a modified ultra-hydrophobic zeolite-Y, and optionally adding a binder, kneading, rolling, pressing and moulding into carrier, and then supporting active hydrogenation metals onto said carrier to obtain the catalyst of the invention. These and other objects of the present invention will become apparent to the person skilled in the art after reading the specification. DETAILED DESCRIPTION OF THE INVENTION The hydrocracking catalyst according to the present invention comprises hydrogenation metal components, a modified ultra-hydrophobic zeolite-Y, a specific amorphous silica-alumina and optionally an alumina binder, wherein said zeolite-Y has a SiOj/Al3O3 molar ratio of 5-25, a crystal unit cell size of 2.420-2.445nm, an acidity measured by the Pyridine Adsorption IR Method (hereinafter referred to as IR acidity, conducted by the acidimeter Necolet 555) of 0 . 2-0 . 6mmol/g, a sorptive capacity for water vapor of less than 5wt% at 25°C and P/Pg of 0.1, and a specific surface area of 600-850m^/g; and said amorphous silica-alumina has a SiO2content o±15-5Qwt%, a specific surface area of 300-600m2/g, a pore volume of 0.8-1. 5ml/g and an IR acidity of 0.25-0.60mmol/g. The hydrogenation metals used in the catalyst of the present invention are preferably selected from the group consisting of Groups VIB and VIII metals, more preferably Mo and/or W, and Co and/or Ni. And the metal components are preferably metal oxides, most preferably molybdenum oxide and/or tungsten oxide, cobalt oxide and/or nickelous oxide. The catalyst according to the invention has a specific surface area of 180-300m2/g, preferably 200-250m2/g; and a pore volume of 0 .25-0.45ml/g, preferably 0.3-0.4ml/g. The catalyst according to the present invention preferably comprises a Group VIB metal component (calculated as oxide(s)) of 10-40wt%, a Group VIII metal component (calculated as oxide (s) ) of l-20wt%, an ultra-hydrophobic zeolite-Y of S-"IOwtyo, an amorphous silica-alumina of 10-70wt%, and a binder of 0-40wt%. The catalyst according to the present Invention more preferably comprises a Group VIB metal component (calculated as oxide(s)) of 10-35wt%, a Group VIII metal component (calculated as oxide (s)) of l-15wt%, an ultra-hydrophobic zeolite-Y of 5-35wt%, an amorphous silica-alumina of 10-60wt%; and a binder of 5-35wt%. The catalyst according to the present Invention most preferably comprises a Group VIB metal component (calculated as oxide(s)) of 15-30wt%, a Group VIII metal component (calculated as oxide (s)) of 2-10wt%, an ultra-hydrophoblc zeollte-Y of 10-30wt%, an amorphous silica-alumina of 15-50wt% and a binder of 10-30wt%. The catalyst according to the present invention most preferably comprises Group VIB metal oxide (s) of 18-28wt%, Grout: VIII metal oxide (s) of 4-8wt%, a ultra-hydrophobic zeolite-Y of 10-25wt%, a specific amorphous silica-alumina of 20-40wt%, and a binder (calculated as dry alumina) of 15-30wt%. The ultra-hydrophoblc zeollte-Y used In the catalyst according to the Invention has a SI02/AI2O3 molar ratio of 5-25, an IR acidity of 0.2-0.6mmol/g and a sorptive capacity for water vapor of less than 5wt% at 25C and P/Po of 0.1. Preferably, said ultra-hydrophobic zeolite-Y has a Sioz/AbOa molar ratio of 6.0-17; an appropriate proportion of non-skeletal alumina, which accounts for 10-50wt% based on the total weight of alumina contained in the zeolite; a very narrow range of crystal unit cell size, generally between 2.420 and 2.445nm, most preferably between 2.425 and 2. 435nm. The ultra-hydrophobic zeollte-Y according to the present invention has obviously secondary pores,that Is, the modified zeollte-Y has an Increased number of medium pores, accompanied by the increase in specific sur^ce area and pore volume. Said zeoiite-Y has a specific surface area of 600-850m2/g, preferably700-800m2/gj a pore volume of 0.2-0.6ml/g, preferably 0.3-0.5m!/g, with more than 50% of the total pore volume being contributed by the secondary pores having diameters of over 2nm; and an IR acidity of preferably 0.3-0.5mmol/g. The amorphous silica-alumina used in the catalyst according to \ht invention has a Si02 content of 10-50wt%; a specific surface area of 300-600mVg, a pore volume of 0.8-l.Sml/gandanlRacidity of 0.25-0.&0mmol/g. Preferably, said amorphous silica-alumina is one v;hlch has a SiO^ content of 15-50wt%, preferably 20-40wt%, a specific surface area of 350-550mVg, preferably 400-SOOnf/g; a pore volume of Q.9-1.4ml/g, preferably 1.0-1.3ml/g, and an IR .acidity of 0.30-0.55mmol/g, preferably 0.35-0.50mmol/g. The amorphous silica-alumina according to the present invention may optionally contain phosphorus, preferably of l-5wt% calculated as P2O5 A binder is preferably used in the catalyst of the present invention, which is preferably an alumina binder and most preferably a small pore alumina which is peptized with nitric acid and has a specific surface area of 240-280mVg and a pore volume of 0.4-0.5ml/g, The catalyst of the present invention can be prepared by mixing the above mentioned amorphous silica-alumina of IO-50wt%, the above mentioned ultra-hydrophoblc zeolite-Y of 5-40wt%, and optionally adding a binder, kneading, rolling and pressing the blend into block mass, and extrusion moulding the block mass by an extruder into carrier bars ; and then supporting active hydrogenation metals onto said carrier by a conventional method such as impregnation to obtain the catalyst of the Invention. The moulded carrier bars may be in any suitable shape, for example, a cylindrical shape having a diameter of 1.2-1.8mm, or be in the specific shapes, such as those of clover or four-leaf clover. Before supporting active hydrogenation metals onto the carrier, the moulded carrier bars can be dried at a temperature of 90-160.C, preferably IIC-140"C for 6-12 hours, preferably 8-10 hours, and activated by calcination at a temperature of 400-650°C, preferably 450-600°C for 1-10 hours, preferably 3-6 hours to obtain the carriers ready for use. The ultra-hydrophobic zeolite-Y according to the invention may be prepared in the following steps: (1) preparing a zeolite-Y (I) having a Na2O content of less than 0.2wt%; (2) adding the zeolite-Y to a high-temperature calcining oven, calcining at 450-700°C and under a pressure of 0.01-l.OMPa of water vapor produced on-site or additonally introduced, for 0 . 5-10 hours to obtain an ultra-hydrophobic zeolite-Y (II) having a SiOj/AljOj molar ratio of 5.2-6.0. The ultra-hydrophobic zeolite-Y obtained according to the above steps may be further dealuminized selectively by a chemical method to obtain an ultra-hydrophobic zeolite-Y having a SiOj/AljOj molar ratio of 6.5-25. The chemical method for the selective dealuminization is carried out to remove selectively the non-skeletal alumina in the zeolite with a solution of an acid, such as hydrochloric acid, nitric acid, acetic acid, oxalic acid and the like, or of an organic complexing agent, such as acetylacetone, ETDA and the like. And the zeolite-Y having a Na2O content of less than 0.2wt% can be prepared according to the following methods of (a) or (b) : (a) stirring a commercial zeolite NaY as starting material in an ammonium ion-exchanging solution having a concentration of 1.0-5.OM, preferably 2.0-3.OM, in which the concentration of the zeolite NaY is 0.05-1.Og/ml, preferably 0.1-0.5g/ml, at a temperature of 70-150°C, preferably 80-120°C, for 0.5-3 hours, and repeating the above ion-exchanging step again and again till a zeolite-Y having a NajO content of less than 0 . 2wt% is obtained; or (b) ion-exchanging a commercial starting material zeolite NaY according to the same ion-exchanging method as mentioned in (a) for 2-3 times to obtain the zeolite-Y product (I) having a Na20 content of less than 3.0wt%, which is then hydrothermally treated at 450-600°C and under a vapor pressure of 0.01-0.2MPa for 0.5-3 hours; then ion-exchanging the resulting zeolite-Y by the same ion-exchanging method as mentioned in (a) for 2-3 times to obtain the zeolite-Y having a NazO content of less than 0 . 2wt%. The amorphous silica-alumina according to the invention can be prepared by the following steps: (a) adding an acidic aluminum salt solution and a basic precipitant simultaneously to a reaction vessel containing a smali amount of deionized water and carrying out the neutralization reaction at a pH value of 6.0-10.0 and a temperature of 50-80° C for 0.5-2 hours to form a sol; (b) stabilizing the resulting sol from step (a) at pH 6-9 for 0-60 minutes; (c) adding a silicon compound within 5-10 minutes to the resulting sol from step (b); (d) aging the mixture from step (c) at pH 7.5-9.5 and a temperature of 50-70°C for 10-60 minutes; (e) filtering and washing the resultant from step (d); and (f) dr/ing the material from step (e) at 90-120°C and crushing it to obtain the final product amorphous silica-alumina. The acidic aluminum salt used in step (a) is one or more salts selected from the group consisting of aluminum sulfate, aluminum chloride and aluminum nitrate, and the basic precipitant is one or more compounds selected from the group consisting of sodium alumlnate, aqueous ammonia and sodium hydroxide. The silicon compound used in step (c) can be waterglass or a silica sol or other silicon compounds of industrial grade. The amorphous silica-alumina containing phosphorus can be obtained by slurrying the resultant from step (e), adding a proper amount of phosphorus compound such as phosphoric acid or other compounds containing phosphorus so that the product contains l-5w% P2O5 based on the total weight of the amorphous silicaalumina product, then filtering, drying and crashing to give the product containing phosphorus. The hydrocracking catalyst according to the prwent Invention Is characterized In that it comprises a modified zeolite-Y and a specific amorphous silica-alumina. The modified zeoiite-Y used in the catalyst according to the invention has an increased molar ratio of SiOi/AlzOa and a further decreased amount of solid acid. After deeply dealuminized, said modified zeolite-Y has a decreased number of acid sites, and a decreased IR acidity of 0.2-0.6 mmol/g, preferably 0.3-0.5 mmol/g. Compared with the zeollte-Y prepared by the prior art, the zeolite used in the catalyst according to the present Invention has a larger specific surface area, and an added number of weak and moderate acid sites being formed with most of them being weak, and moderate acid sites desorbed at a temperature ranging from 160 to 450C and the strong acid sites desorbed at >450°C being less than 25% (that is, after modified, the acid sites of the zcolite-Y have been decreased very much, but tiie strong acid sites have not been vanished compietety) , thus ensuring that no over cracldng wiil occur, while a certain amount of strong add sites can also ensure adequate cracldng activity of the catalyst. The properties of pores, including the larger specific surface area and more secondary pores, shown in the modified zeolite used In the catalyst according to the invention enhance efficiently the hydrogenatlon activity which Is advantageous to the Increase in the activity of the ring-opening reaction of multi-ring aromatlcs or heterocyclics containing nitrogen, and provide more efficient reaction space to meet the requirements of the mid-distillate type hydrocracking catalyst for moderate cracking activity and high hydrogenatlon activity for cracking heavy hydrocarbon materials. The amorphous silica-alumina of the prior art has relatively small specific surface area and pore volume with the specific surface area being not more than 300mV0/ so when used as the carrier of the catalyst, It needs generally to be used in combination with Y -AI2O3 to support a large amount of metal components. The preparation process of the amorphous silicaaiumina used in the catalyst according to the present invention is characterized In that the formation of undesirable pore structure under the tendency of crystallization is avoided, thus ensuring the effective interaction of silicon and aluminum atoms to provide acid sites as well as a large specific surface area and large pore volume. The amorphous silica-alumina can have a pore volume of 0.8-1.5ml/g, and can still have a large specific surface area and large pore volume even in a very wide range of high SIO2 content. For example, when the SIO2 content Is 45% , the specific surface area can stiil be within the range of this invention. A large specific surface area makes the amorphous silica-alumina capable of supporting a large amount of metal components for hydrogenation, while the ackl sites can provide it with the cracking activity. The large pore volume is beneficial for easy movement of the reactants and products in and out of the cavities of the catalyst, and thus minimizing the opportunity of secondary cracking reaction, while less carbon deposition wilt prolong the service life of the catalyst. The ultra-hydrophobic zeolite-Y mentioned above Is used as a main acidic component of the hydrocracWng catalyst of the Invention. The addle property of the zeolite will provide the catalyst with relatively moderate cracking activity; the large specific surface area and secondary pore structure will improve the dispersion of hydrogenation metals to give full play to the hydrogenation activity, and improve the pore distribution in the catalyst, thus being of benefit to cracking oil distillates. In addition, the amorphous silica-alumina according to the invention is used as a supplement acidic component and a main carrier component of the catalyst, so It has a dual-function, for supplementing the acidic cracking function and serving as a main carrier component for supporting the hydrogenation metals. Said amorphous slllca-aiumina has appropriate acidity and acid strength ard can provide relatively moderate cracking activity when matched with the zeolite. Therefore, compared with the mid-distillate type hydrocracking catalyst prepared by the prior art, the mid-distillate type hydrocracking catalyst according to the present invention has the features of higher activity and obviously higher mid distillate selectivity. Compared with the reference catalysts, the catalyst of the present Invention exhibits better activity and mid-dlstlllate selectivity In treating the same vacuum gas oils (VGO) under the same conditions. The preparation process of the catalyst according to the present invention is simple and convenient, easy to operate and suitable for industrial production. The catalyst according to the present invention is designed for use in hydrocracldng process to produce middle distillates. In particular, the catalyst according to the invention is suitable for treating heavy hydrocarbon materials having a distillation range of 250-600®C, generally 300-550C, for example, gas oils, vacuum gas oil distillates, deasphaited oils, cycle oils of FCC, shale oil, coal tars and the tike. The hydrocracking reaction according to the invention is generally carried out at a temperature of S"W) -420°C in the presence of hydrogen under a pressure of 5-30MPa, with the H/oil ratio being 100-5000 and the space velocity being O.l-5.0h-l. When the catalyst of the Invention (s used for treating conventional VGO, the hydrocracking reaction Is generally carried out at a temperature of 370-410C in the presence of hydrogen under a pressure of preferably 10-20MPa with the H/oil ratio being 500-2000 and the space velocity being 0.5-1.5h-^ EXAMPLES The present invention is further illustrated in detail with reference to the following examples which are provided for purposes of illustration and shall not be construed as limiting the present invention. Example i This example relates to the ultra-hydrophobic zeolite-Y (No. A) to be used in the catalyst according to the invention. (1) To an IM" Ion-exchanging vessel witti enamel inner-lining, 130kg NH4NO3 (product of industrial grade with a purity of > 99.5%, available from the Dalian Chemical Factory) and 800L Industrially purified water were added to prepare a 2M NH4NO3 solution, then the solution was heated to 70"C, 120kg zeolite NaY (50wt% calculated as dry basis, product available from the Wenzhou Catalyst Factory) was added, and ion-exchanged with stirring at 70°C for 3 hours. This exchanging step was repeated for 12 times. Then, the resulting mixture was filtered and washed with water to neutrality^ and dried to obtain the zeolite-Y having a NaaO content of 0.18 %. (2) The washed and dried zeolite obtained above was placed in a high pressure rotary oven, with the temperature being rapidly raised to 650°C and calcined under a pressure of 0.4MPa In the presence of 100% water vapor for 6 hours to obtain the ultra-hydrophobic zeolite-Y (No. A) to be used in tiie catalyst according to the invention. The physical and chemical properties of the zeolite are shown in Table 1. Example 2 This example relates to the ultra-hydrophobic zeolite-Y (No B) to be used in the catalyst according to the invention. (1) 5.0kg of zeolite IMaY (the same as that in Example 1) was added to 50 liters of the 2M NH4NO3 solution, and ion-exchanged at 100C with stirring for 2 hours for two times, then the resulting mixture was filtered, washed to neutrality, and dried to obtain, the product (I) ; (2) the product (I) was placed in the highpressure rotary oven and calcined at 550°C under a pressure of O.lMPa in the presence of 100% water vapor for 2 hours to obtain the produd: (II) ; (3) the product (II) was added to 50 liters of the 2M NH4NO3 solution, then ion-exchanged with stirring at 100°C for 2 hours for three times, and then filtered and washed with water to neutrality, and dried to obtain the product (III); (4) the product (III) was placed In a high pressure rotary oven and calcined at 550C under a pressure of 0.2MPa In the presence of 100% water vapor for 4 hours to obtain the ultra-hydrophobic zeollte-Y (No. B) to be used in the catalyst according to the invention. The physical and chemical properties of the zeolite are shown in Table 1. Example 3 This example relates to the ultra-hydrophobic zeollteY (No. Q to be used in the catalyst according to the Invention, (1) 2.0kg of zeolite NaY (the same as that m Example 1) was added tx) 160 liters of the 3M NH4NO3 solution, and ion-exchanged at ISO** C with Stirring for 0.5 hour for 12 times to obtain the zeolite-Y with a NaiO content of 0.1 7wt%, then dried to obtain tlie product (I) ; (2) the product (I) was placed in a high pressure rotary oven and calcined at 700^C under a pressure of O.lMPa in the presence of 100% water vapor for 4 hours to obtain the product (II) ; (3) 400g of the product (II) was added to 4 liters of 0.4M hydrochloric acid solution and treated for 2 hours, then filtered and washed to neutrality, and dried to obtain the ultra-hydrophobic zeollte-Y (No. C) to be used in the catalyst according to the Invention. The physical and chemical properties of the zeolite are shown In Table 1. Example 4 This example relates to the ultra-hydrophobic zeolite-Y (No. D) to be used in the catalyst according to the invention. lOOg ultra-hydrophobic zeolite-Y (No. A) from Example 1 was added to 1 liter of the 0 . 4M acetylacetone solution and treated for 2 hours, then filtered and washed with 3 liters of deionized water, then dried to obtain the ultra-hydrophobic zeolite-Y (No. D) to be used in the catalyst according to the invention. The physical and chemical properties of the zeolite are shown in Table 1. Example 5 This example relates to the amorphous silica-alumina product S-1 to be used in the catalyst according to the invention. 3.2 liters of a concentrated solution of industrial aluminum sulfate was added to 4.2 liters of distilled water and heated with stirring to obtain an aluminum sulfate solution (al) having a concentration of Al3O3 of 6g/100ml. A concentrated aqueous ammonia was diluted with appropriate volume of distilled water to obtain a dilute ammonia solution (b) having a concentration of about 10%. 5 liters of distilled water was added to 2.4 liters of industrial water-glass having a concentration of 3.0 module to obtain a dilute water-glass solution (c) . To a lOL steel reaction vessel, 2 liters of distitied water was added and heated with stirring to 70^C, then a neutralization reaction was carried out by turning on simultaneously the valves of vessels containing the aluminum sulfate solution and the ammonia solution respectively v/ith the flow of (al) being set at a given rate to keep pace with the neutralization reaction which was required to be carried on for 40 minutes to provide 600 g of the amorphous slllca-alumlna product, the flow of (b) being adjusted promptly to maintain the pH value in the system at 9.0, and the temperature in the reaction system being controlled at 55C. After the reaction of aluminum sulfate was completed, feeding of the ammonia liquor was stopped. The resulting alumina sol was stabilized for 30 minutes, then 1.4 liters (calculated amount) of (c) was added over 10 m"muHxis. The mixture was aged at 60°C for 30 minutes with the pH value being maintained at about 9.0. Then, the colloidal solution was filtered, and the resultant wet filter cake was pulped and washed with distilled water, and the resulting slurry was filtered to obtain filter cake(d), which was dried at 110C for 8 hours, and crushed and screened to obtain the amorphous silica-alumina product S-1 to be used in the catalyst according to the invention. Exampi« 6 This example relates to the amorphous silica-alumina product S-2 to be used in the catalyst according to the invention, 3.5 liters of a concentrated solution of industrial aluminum nitrate was added to 4.0 liters of distilled water and heated with stirring until completely dissolved to obtain an aluminum sulfate solution (a2) having a concentration of AI2O3 of 8g/100ml. A concentrated aqueous ammonia was diluted with an appropriate volume of distilled water to obtain a dilute ammonia solution (b) having a concentration of about 10%. To a lOL steel reaction vessel, 2 liters of distilled water was added and heated with stirring to 70PC, then the neutralization reaction was carried out by turning on simultaneously the valves of vessels containing the aluminum nitrate solution and ammonia solution respectively with the flow of (a2) being set at a given rate to keep pace with the neutralization reaction which was required to be carried on for 1.5 hours to provide 600 g of the amorphous silica-alumina product, the flow of (b) being adjusted promptly to maintain the pH value in the system at 8.5, and the temperature in the reaction system being controlled at 55°C. After the reaction of aluminum nitrate was completed, feeding of the ammonia liquor was stopped. The resulting alumina sol was stabilized for 15 minutes, then 6.2 liters (calculated in accordance with the desired content of SIO2 in the final product) of (c) from Example 5 was added over 5 minutes. Tlie mixture was aged at 65°C for 15 minutes with the pH value being maintained at 8.5. Then, the colloidal solution was filtered, and the resultant wet filter cake was pulped and washed with distilled water, and the resulting slurry was filtered to obtain filter cake (d), which was pulped again, and 31.5 ml of phosphoric acid was added to the slurry s^nd stirred continuously for 30 minutes, and filtered to obtain the filter cake (e), which was dried at 110°C for 8 hours, crushed and screened to obtain the amorphous slllca-alumina product S-2 to be used in the catalyst according to the invention. Example 7 This example relates to the amorphous silica-alumina product S-3 to be used in the catalyst according to the invention. A concentrated solution of industrial sodium alumlnate was added to 5.0 liters of distilled water and heated with stirring until homogeneously mixed to obtain a sodium alumlnate solution (a3) having a concentration of AI2O3 of 18g/100ml. An industrial AI2 (504)3 solution was diluted with an appropriate volume of distilled water to give an AI2 (S04)3 solution (b) having a concentration of 4g/100 ml. To a lOL steel reaction vessel, 2 liters of distilled water was added and heated with stirring to 70^C, then the neutralization reaction was carried out by turning on simultaneously the valves of vessels containing aluminum sulfate solution and sodium alumlnate solution respectively with the flow of (a3) being set at a given rate to keep pace with the neutralization reaction which was required to be carried on for 1 hour to provide 600 g of the amorphous slllca-alumina product, the flow of (b) being adjusted promptly to maintain the pH value in the system at 8.0, and the temperature in reaction system being controlled at 60^C. After the reaction was completed, the resulting alumina sol was stabilized for 40 minutes, then 3.3 liters (calculated in accordance with the desired content of SiO2 in the final product) of (c) from Example 5 was added over 10 minutes. The mixture was aged at 50°C for 40 minutes with the pH value being maintained at 8.5. Then, the colloidal solution was filtered, and the resulting wet filter cake was pulped and washed with distilled water, and the resulting slurry was filtered again to obtain filter cake (d) , which was dried at 110°C for 8 hours, and crushed and screened to obtain the amorphous silica-alumina product S-3 to be used in the catalyst according to the invention. Example 8 This example relates to the amorphous silica-alumina product S-4 to be used in the catalyst according to the invention. 3 liters of a concentrated solution of aluminum chloride was added to 4.0 liters of distilled water and heated with stirring until homogeneously mixed to obtain the aluminum chloride solution (a4) having a corresponding AI2O3 concentration of 4g/100ml. A concentrated aqueous ammonia was diluted with an appropriate volume of distilled water to obtain a dilute ammonia solution (b) having a concentration of about 10%. To a lOL steel reaction vessel, 2 liters of distilled water was added and heated with stirring to 70°C, then the neutralization reaction was carried out by turning on simultaneously the valves of vessels containing aluminum chloride solution and ammonia solution respectively with the flow of (a4) being set at a given rate to keep pace with the neutralization reaction which was required to be carried on for 40 minutes to provide 600 g of the amorphous silica-alumina product, the flow of (b) being adjusted promptly to maintain the pH value in the system at 9.0, and the temperature in reaction system being controlled at 55°C. After the reaction of aluminum chloride was completed, the feeding of ammonia solution was stopped. The resulting alumina sol was stabilized for 30 minutes, then 2.0 liters (calculated in accordance with the desired content of SiO2 in the final product) of (c) from Example 5 was added over 10 minutes. The mixture was aged at 60°C for 30 minutes with the pH value being maintained at 9.0. Then, the colloidal solution was filtered, and the resulting wet filter cake was pulped and washed with distilled water, and the resulting slurry was filtered again to obtain filter cake(d), which was dried at This example relates to the carrier SA and the catalyst (Cat .A) according to the invention. 102.5 g of the amorphous silicaaiumina product S-1 from Example 5 according to the invention and 60.5 g of the zeolite-Y (No. C) from Example 3 according to the invention were weighed and mixed homogeneously, then 250g of a jelly binder prepared by peptizing the small pore alumina having a pore volume of 0,42ml/g with nitric acid was added to the resulting mixture, rolled and pressed into mass, and extruded by an extruder into bars, which were dried at 110°C for 10 hours and activated at 500°C for 4 hours to obtain the carrier SA, which was Impregnated In a co-Impregnation solution containing W and Ni so that the catalyst finally contained 7wt% nickel oxide and 22 wt% tungsten oxide, then the Impregnated carrier was dried at 110°C for 12 hours and activated at SOO^"C for 3 hours to obtain the catalyst Cat.A. Example 10 This example relates to the carrier SB and the catalyst (Cat. B:) according to the invention. 126.5 g of the amorphous silicaaiumina product S-2 from Example 6 according to the invention and 30.5 g of the zeotite-Y (No. C) from Example 3 according to the invention were weighed and mixed homogeneously, then 250g of a jelly binder prepared by peptizing the small pore alumina having a pore volume of 0.42m!/g with nitric acid was added to the resulting mixture, rolled and pressed Into mass, and extruded by an extruder into bars, which were dried at 100ac for 11 hours and activated at 500C for 4 hours to obtain the carrier SB, which was impregnated in a co-impregnation solution containing W and Ni so that the catalyst finally containing 7wt% of nicicei oxide and 22wt% of tungsten oxide, then the impregnated carrier was dried at 110C for 12 hours and activated at 500C for 3 hours to obtain the catalyst CatB. Comparative Example 1 This comparative example relates to the reference carrier SC and reference catalyst Cat.C. 104.8 g of the silica-alumlna having a spedfk: surface arm of 280m^/g, a pore volume of 0.76ml/g and a S1O: content of 35wt% (an industrial silica-alumina product manufactured by the Catalyst Factory of the Fushun Petro¬chemical Corporation) and 30.5g of the zeolite-Y component which was the same as that in Example 10 were weighed and mixed homogeneously, then 250g of a jally binder prepared by peptizing the small pore alumina having a pore volume of 0.42ml/g with nitric acid was added to the resulting mbcture, roiled and pressed into mass, an(^ extruded l7y an extruder into bars, which were dried and activated to obtain the carrier 3C. 60g of the carrier SC was saturatediy impregnated in 48ml of a co-impregnab"cn. solution containing W and Ni, then the impregnated carrier was dried and activated to obtain the reference catalyst Cat. C. The conditions for drying and activation were the same as those in Example 9. Comparative Example 2 The comparative Example 2 relates to the reference canler SD and reference catalyst Cat.D. 28.9 of the zeolite-Y having of a molar ratio of SKVAIzOa) of 12, an m acidity of 0.94mmol/g (manufactured by the Catalyst Factory of the Fushun Petro¬chemical Corporation) and 126.5 g of the silica-alumina which was the same as that in Example 10 were weighed and mixed homogeneously, then 250g of a jelly binder prepared by peptizing the small pore alumina havbig a pore volume of 0.42ml/g with nitric acid was added to the resulting mixture, rolled and pressed into mass, and extruded by an exbuder into bars, which were dried and activated to ot^ln the canler SD. 60g of the carrier SD was saturatediy Impregnated In 46ml of a co-Impregnation solution containing W and Ni, then the impregnated carrier was dried and activated to obtain the reference catalyst Cat.D. The conditions for drying and activation were the same as those in Example 9. Example 11 This example relates to the carrier SE and the catalyst (Cat. E) according to the invention. 128.6 g of the amorphous silica-alumina product S-2 from Example 6 according to the invention and 11.1 g of the zeolite-Y (No. B) from Example 2 according to the invention were weighed and mixed homogeneously, then 250g of a binder prepared by peptizing 71. 4g of the small pore alumina having a pore volume of 0 .42ml/g with dilute nitric acid was added to the resulting mixture, rolled and pressed into mass, and extruded by an extruder into bars, which were dried at 110°C for 10 hours and activated at 500°C for 4 hours to obtain the carrier SE, which was impregnated in a co-impregnation solution containing Mo and Ni, then the impregnated carrier was dried at 110C for 12 hours and activated at 500"C for 3 hours to obtain the catalyst Cat.E, which finally consisted of silica-alumina of 45wt%, zeolite of 5wt%, alumina of 25wt%, nickelous oxide of 5wt% and molybdenum oxide of 20wt%. Example 12 This example relates to the carrier SF and the catalyst (Cat. F) according to the invention. 88 . 7g of the amorphous silica-alumina product S-4 from Example 8 according to the invention and 45.4g of the zeolite-Y from Example 1 according to the invention were weighed and mixed homogeneously, then 222g of a binder prepared by peptizing 57 . Ig of the small pore alumina having a pore volume of 0.42ml/g with dilute nitric acid was added to the resulting mixture, rolled and pressed into mass, and extruded by an extruder into bars, which were dried at 110°C for 10 hours and activated at 500 °C for 4 hours to obtain the carrier SF, which was impregnated in a co-impregnation solution containing W and Ni, then the impregnated carrier was dried at 110°C for 12 hours and activated at 500°C for 3 hours to obtain the catalyst Cat.F, which finally consisted of silica-alumina of 30wt%, zeolite of 20wt%, alumina of 2 0wt%, nickelous oxide of 7.5wt% and tungsten oxide of 22.5wt%. Example 13 This example relates to the carrier 8G and the catalyst (Cat. G) according to the Invention. 64.7g of the amorphous silica-alumina product S-1 from Example 5 according to the Invention and 60.5g of the zeollte-Y from Example 4 (NO.D) according to the invention were weighed and mixed homogeneously, then 167g of a bindo- prepared by peptizing 42.0g of the small pore alumina having a pore volume of 0. 42ml/g witH dilute nitric add was added to the resulting mixture, rolled and pressed into mass, and extruded by an extruder into bars, which were dried at UO.C for 10 hours and activated at 500°C for 4 hours to obtain the carrier SG, which was impregnated in a co-impregnation solution containing W and Ni, then the impregnated canler was dried at llO^C for 12 hours and activated at 500C for 3 hours to obtain the catalyst Cat.G, which finally consisted of slUca-alumlna of 20wt%, zeolite of_30wt%, alumina of 15wt%, nickelous oxide of 7.5wt% and tungsten oxide of 22.5wt%. Example 14 This example relates to the carrier SH and the catalyst (CatH) according to the invention. 184.6g of the amorphous silicaalumina product S-3 from Example 7 according to the invention and 89.8g of the zeolite-Y from Example 3 according to the invention were weighed and mixed homogeneously, then 310ml of 3.9vol% diluted nitric add solution was added to the-resulting mixture, rolled «id pressed into mass, and extruded by an extruder into bars, which were dried at llO^C for 10 hours and activated at SOO^C for 4 hours to obtain the catalyst Cat.H, which finally consisted of silica-alumina of 60wt%, zeolite of 40wt%, nickelous oxide of 7.5wt% and tungsten oxide of 2.5wt% at 500X for 4 hours Comparative Example 3 This comparative example relates to the reference carrier SI. and the reference catalyst (Cat. I). The reference carrier mid the reference catalyst were prepared according to the same procedure as described in Example 12 except that the amoiphous silica-alumina was substituted with a commercial silica-alumina (having a specific surface area of 280mVg and a pore volume of 0.76ml/g, available from the Catalyst Factory of the Fushun Research Institute of Petroleum and Petrochemicals, SINOPEC, the P. R. China). TTie final catalyst consisted of silica-alumina of 30wt%, zeolite of 20wt%r alumina of 20wt%, nickeious oxide of 7.5wt% and tungsten oxide of 22.5wt%. Comparaitive Example 4 This comparative example relates to the reference canlcr S3 and the reference catalyst (Cat. J) . Tlie reference carrier and the reference catalyst were prepared according to the same procedure as described in Example 12 except that the zcofite was substituted with a commercial zeolite (having a SHO2/A1.2Q3 ratio of 12, IR acidity of O.94mmoi/g and a crystal unit cell size of 2.445nm, available from the Wenzhou Catalyst Factor/, the P. R. China) . The final catalyst consisted of silica-alumina of 30wt%, zeolite of 20wt%, alumina of 20wt%, nickelous oxi4e of 7.5wt% and tungsten oxide of 22.5wt%. Comparative Example 5 This comparative example relates to the reference catayst (Cat. K) . The reference catalyst was a high and middle distillate type hydrocracking catalyst which was commercially avaibble from the international market and contained a zeolite component having properties of zeolite-Y, a silica-alumina, an alumina and supported hydrogenation tungsten and nickel component. All the catalysts according to the invention and the reference catalysts were evaluated for their perfermances. The evaluation was carried out with Shengli VGO as the feed oil under a pressure of 14MPa, a Hz/dl volume ratio of 1500 and a space velocity of 1. 5h-1. Main properties are shown in Table 4. The evaluation for tiie catalyst activity was measured by comparing the reaction temperatures at which the same converskm could be achieved using the tested catalyst in once-through process, and the evaluation of the catalyst for mkl-distillate sdectivity was carried out according to the product distributions at a given conversion, in which the mid-distillate selectivity was calculated as the ratio of the yiek) of mkklle distillates to the total yiekl of the products having a distillation range below 370C. It can be seen from the data and the physicchemteal properties of the carriers and the catalysts shown in Table 3 that the carriers and catalysts from the comparative examples have smaller pore volume and lower specific surface area, which will undoubtedly affect the dispersion of metals and. their hydrogenation activity, and moreover, owing to the exceedingly strong acidity of the zeolite used in the comparative catalyst, no substantial improvement in the mkl-distillate selectivity of the catalysts is achieved. The evaluation results In Table 5 also show that when used for treating a heavy feed oil having high aromatic content and high dry point of distillation range with a conversk>n of not less than 65vol%, the catalysts of the present We Claim 1. A hydrocracking catalyst for producing middle distillates; comprising hydrogenation metal components, a modified uitra-hydrophobic zeoUte-Y, a specific amorphoui siiica-alumina and optionally an alumina binder, wherein said zeolite-Y has a Si02/Al203} molar ratio of 5-25, a crystal unit cell size of 2.420-2.445nm, an tR acidity of O.2-0.6mmol/g, a sorptive capacity for water vapor of less than Swt% at 25"C and P/Po of 0.1, and a specific surface area of 600-850mVg; and said amorphous silica-alumina has a Si02 content of 10-50wt%, a specific surface area of 300-600m2/g, a pore volume of 0.8-1. 5ml/g and an IR addity of 025-0.60mmol/g. 2. A catalyst as claimed in daim I, who^n said hydrogenation metal compon^its are Groups VIB and VZn metal components. 3. A catalyst as claimed in claim 2, wherein said metal components are Groups VIB and vm metal oxides, such as molybdenum oxide and/or tungsten oxide, cobalt oxide and/or nickelous oxide. 4. A catalyst as claimed In daim I, wherein said catalyst has a specific surface area of 180-300mV9, and a pore volume of 0.25-0.45ml/g. 5. A catalyst as claimed in claim I, wherein said catalyst has a specific surface area of 200-250mVg, and a pore volume of 0.30-0.40ml/g. 6. A catalyst as dalmed In claim 2, wherein said catalyst comprises a Group VIB metal component (calculated as oxide (s)} of 10-40wt%, a Group vm meial component (calculated as oxide (s) ) of l-20wt%, an uHra-hydrophoblc zeolite-Y of 5-40wt%, an amorphous sllica-alumtna of 10-70wt%, and a lender of 0-40wt%. 7. A catalyst as claimed in claim 2, wherein said catalyst comprises a Group VIB metal component (calculated as oxlde(s)) of 10-35wt%, a Group Vm metal component (calculated as oxide (s)) of l-15wt%, an uitra-hydrophobic zedite-Y of 5-35MA%, an amorphous silica^lumina oF 10-60wt%, and a binder of 5-35wt%. 8. A catalyst as claimed In dalm 2, wherein said catalyst comprises a Group VIB metal component (calculated as oxlde(s)) of 15-30wt%, a Group vm metal component (cakuiated as oxide (s)) of 2-10wt%, an uitra-hydrophobic zeotite-Y of 10-30wt%, an amorphous silica-alumina of 15-50wt%, and a binder of 10-30wt%. 9. A catalyst as claimed in claim 2 or 3, wherein said catalyst comprises Group VIB metal oxide (s) of 18 -28wt%, Group vni metal oxideCs) of 4-8wt%, a uitra-hydrophobic zeoilte-Y of l0-25wt%, a specific amorphous silica-alumina of 20-40wt%, and a binder (calculated as dry alumina) of 15-30wt%. 10. A catalyst as claimed in claim 1, wherein said zeolite-Y has a Si02/Al2O3 molar ratio of 6.0-17, a crystal unit ceil size of 2.425-2.435nm, a spedfic surface area of 700-800m2/ and an IR acidity of 0.30-0.50mmol/g, with more than 50% of the total pore volume being contributed by the secondary pores having pore size of >"h\m. 11. A catalyst as claimed in claim 1, wherein said amorphous siilca-alumlna has a Si02 content of i5-50wt%, a specific surface area of 350-550m^ /g, a pore volume of 0.9-1. 4ml/g and an IR acidity of 0.30-0.55mmol/g. 12. A catalyst as claimed in claim 1, wherein said amorphous silica-alumina has a Si02 content of 20-40wt%, a specific surface area of 400-500mVg« a pore wlume of 1.0-1.3mi/g and an IR acidity of 0.35-0.50mmol/g. 13. A process for preparing a catalyst as claimed in claim 1, comprising the steps of mixing an amorphous siilca-alumlna of 10-50wt%, a modified uitra-hydrophobic zeolite-Y of 5-40wt%, and optionally adding a binder, ioieading, roHing, pressing and moulding into a carrier, and then supporting active hydrogenation metab onto said carrier to obtain the catalyst of the invention; wherein said zeoiite-Y has a Si02/Al2O3 molar ratio of 5-25, a crystal unit cdl size of 2.420-2 .445nm, an IR addNy of 0.2^.6mmo^f a sorptive capacity for water vapour of less than 5w% at 25oC and P/Po of 0.i, and a spedHc surface area of 600-850 m2/g; and said amorphous silica-alumina has i SiOz content of 10-50wt%, a spacific surfacea arsa of 300-600mVgf a pore volume of Q,$-1.9nl/g and an IR acidity of 0.25-0.60mmol/g. 14. A process as claimed in daim 13, comprisina the step of adding 15-3(M% of a binder of small pore alumina peptized with nitric add, which has a spedflc surface area of 240-280mVg and a pore volume of O.Ht.SM/g. 15. A process as claimed in daim 13 or 14, wherein said zeolite-Y has a SiO2/AI2O3 molar ratio of 6.0-17, a crysfeil unit cdl size of 2.425-2.435nm, a spedflc surfioa area of 700-8002/g and mn IR acldtty of 030^.50mmol/g, wtth mora than 50% of the total pore volume being contributed by the secondary pores having a pore size of >2nm, and said amorphous sllicaalumina has a SIO2 content of 15-5(^vt%, a spedfle surface area of 350-550mVg/ a pore volume of 0.9-1.4ml/g and an IR addlty of 0.30-0.55mmoi/g. 16. A process as daimed in daim 15, wherein said amorphous silica-alumirHi has a SiOz content of 20-40wt%, a specific surface area of 400-500mVg/ a port volume of 1.0-1.3ml/g and an IR addity of 0.35-0.50mml/g. 17. A process as daimed in daim 13 or 14, wherein said hydrogenation metab comprise Groups VIB and vm metals. 16. A process as claimed in daim 13 or 14, wherdn said hydrogenation metals comprise Mo and/or W and Co and/or Nl. 19. A process as daimed in claim 13 or 14, wherein it comprises the following stsps for the preparation of said zeolite-Y: (1) preparing a zeolite-Y having a Na2O content of less than 0.2wt%; and (2) pladng said zeoiite-Y into a high-temperature caidntng oven, caldning at 450-700X and under a pressure of 0.01-1. OMPa of water vapor produced on-site or additionally Introduoed, for 0.510 hours to obtain an ultra-hydrophobic zeolite-Y having a SiO2/A1zO3a motar ratio of 5.2"6.0. 20. A process at daimod in daim 19, wharain said ultrahydrophobic zeolite-Y it furfhar dealuminized saiadjvaly to obtain an ultra-hydrophobic zaolita-Y having a Si02/Ala03 molar ratio of 6.5-25. 21. A process as claimed in claim 13 or it, wherein it comprises the following steps for the prqpantion of said amorphous silica-alumina: (a) adding an acidic aluminum salt solution and a basic precipitant simuttaneousiy into a reaction vessel containing a small amount of delonlzed water and carrying out the neutralization reaction at a pH value of 6.0-10.0 and a temperature of 50-80°C for 0.5-2 hours to form a sol; (b) stabilizlna the resultir^g sol from step (a) at a pH value of 6-9 for 0-60 minutes; (c) adding a silicon compound into the resulting sol ft^m step (b); (d) aging the mixture from step (c) at a pH value of 7.5-9.5 and a tenrperature of 50-70°C for 10-60 minutes; (e) filtering and washing the resuttsnt from step (d) /end (f) drying the rasuldng materiel from step (e) at 9O-13I0K; and crushing it to obtain the prockict amorphous silicaalumina. 22. A process as claimed in daim 21 wherein said acidic aluminum salt is one or more salts selected from the group consisting of aluminum sulfate, aluminum chloride and aluminum nitrate, and said basic predpltant is one or more compounds sdected from the group consisting of sodium eiuminate, aqueous emmonia and sodium hydro)dde..

Full Text

FIELD OP THE INVENTION
The present invention relates to a hydrocracking catalyst and a process for the preparation thereof, more particularly, to a catalyst for treating petroleum hydrocarbon materials to produce middle distillates and a process for the preparation thereof.
BACKGROUND OF THE INVENTION
Currently, since the refineries in the world have to face the problems that feedstocks become heavier and heavier and qualities of them worse and worse, the hydrocracking process has yet become an important means for lightening heavy oils. The hydrocracking catalyst is a dual-function catalyst possessing the properties of both hydrogenation and cracking. In general, a hydrocracking catalyst containing non-noble metals comprises Groups VIB and VIII metal components as the hydrogenation components, and a crystalline zeolite and/or amorphous silica-alumina as acidic components. Although an amorphous hydrocracking catalyst containing solely amorphous silica-alumina as an acidic component has a relatively high selectivity, its activity is low and operational flexibility limited. However, the application of zeolites in the preparation of hydrocracking catalyst has brought about a qualitative advancement of the hydrocracking technique, contributing to overcoming the defects of low activity and short running cycle in the hydrocracking catalysts containing amorphous silica-alumina as an active component and reducing significantly the reaction temperature of the catalyst. In particular, in order to increase the operational flexibility of the catalyst to meet the requirement for treating the steadily worse-quality feedstocks from the market, the mid-distillate type hydrocracking catalysts commonly used at present in the industry comprise amorphous silica-alumina in combination with zeolite component so as to fulfil the dual requirements of the catalyst for activity and mid-distillate selectivity.

With respect to the mid-distillate type hydrocracking catalyst, in addition to the activity of the catalyst, the mid-distillate selectivity should be especially taken into consideration. The stronger acid sites of zeolite in relation to the acidic silica-alumina can enhance the cracking activity of the catalyst, but its strong cracking activity may result in noticeable decrease in the mid-distillate selectivity. Therefore, it needs to seek a better balance between the activity and the mid-distillate selectivity of the catalyst. In order to solve the contradiction between the reaction activity and the mid-distillate selectivity and according to the requirements for balanced matching of the acidic cracking function and the hydrogenation function of the mid-distillate type hydrocracking catalyst, it needs to develop new-type zeolites and amorphous silica-alumina materials and, through adjusting the ratio of the amorphous silica-alumina to zeolite component in the carrier, to achieve the final object of attaining an optimal level of both the desirable activity and selectivity in the course of reaction.
US Patent No. 4,894,142 discloses a hydrocracking catalyst having an improved mid-distillate selectivity, comprising an amorphous silica-alumina and a low acidity zeolite-Y, wherein said zeolite-Y is characterized in that it has a TPD acidity of less than 2.0mmol/g, preferably 1.5mmol/g. In order to reduce the acidity, the main features of the process for the preparation of said zeolite lie in that the starting material zeolite is treated at a high temperature, including hydrothermally treated at 676~788°C, or dry-treated preferably at 704°C by introducing an inert gas. Since the zeolite has exceedingly low acidity, when a catalyst comprising said zeolite as component is used for treating the feedstock oils, the reaction temperature is over 410°C at the conversion of 85%. Such a high temperature inhibits the hydrogenation reaction while the thermal cracking performance of the zeolite increases, with the result that the mid-distillate selectivity of the catalyst is not obviously improved; specifically, the mid-distillate selectivity is less than 70%, indicating that a better balance has not been obtained for solving the contradiction between the activity and the mid-distillate selectivity as mentioned above.

us Patent No. 4,517,074 discloses a hydrocracking catalyst for producing 300-700°F (149-371°C) middle distillates, wherein the feedstocks are preferably pretreated by hydro-denitrogenation and/or hydro-desulfurization. Said catalyst is characterized in that it comprises, in addition to a zeolite component, a dispersion system of SiO2-Al2O3 in a gamma alumina matrix containing 20-65% SiO2, in which, although the amorphous silica-alumina has a certain level of cracking activity, it has to be dispersed into an alumina matrix, such as large-pore Y -AI2O3 used as a component of the carrier, so as to obtain sufficient pore volume and specific surface area for supporting a large amount of metal components for hydrogenation. Although the catalyst has a relatively high mid-distillate selectivity of more than 80%, its activity is relatively low, thus, in order to achieve a conversion of 60vol%, the reaction temperature must generally be higher than 400°C. An example of the patent showed that by the use of a catalyst comprising silica-alumina of as high as 75% silica content dispersed in Y-AI2O3 in combination with a zeolite, such as zeolite LZ-10, the reaction temperature still need to be at 389°C.
Therefore, there is still a need in the art to develop a hydrocracking catalyst having both good activity and high mid-distillate selectivity, and a process for the preparation thereof.
After extensive studies and experiments, the inventors have discovered a hydrocracking catalyst comprising hydrogenation metal components, a modified zeolite-Y and a specific amorphous silica-alumina, which exhibits the desired properties, and a process for the preparation thereof.
THE OBJECTS OF THE INVENTION
The object of the present invention is to provide a hydrocracking catalyst, comprising hydrogenation metal components, a modified zeolite-Y and a specific amorphous silica-alumina, which has both good activity and high mid-distillate selectivity and is useful in treating heavy hydrocarbon materials to produce middle distillates.

Another object of the present invention is to provide a process for the preparation of the catalyst of the present invention, comprising the steps of mixing a specific amorphous silica-alumina, a modified ultra-hydrophobic zeolite-Y, and optionally adding a binder, kneading, rolling, pressing and moulding into carrier, and then supporting active hydrogenation metals onto said carrier to obtain the catalyst of the invention.
These and other objects of the present invention will become apparent to the person skilled in the art after reading the specification.
DETAILED DESCRIPTION OF THE INVENTION
The hydrocracking catalyst according to the present invention comprises hydrogenation metal components, a modified ultra-hydrophobic zeolite-Y, a specific amorphous silica-alumina and optionally an alumina binder, wherein said zeolite-Y has a SiOj/Al3O3 molar ratio of 5-25, a crystal unit cell size of 2.420-2.445nm, an acidity measured by the Pyridine Adsorption IR Method (hereinafter referred to as IR acidity, conducted by the acidimeter Necolet 555) of 0 . 2-0 . 6mmol/g, a sorptive capacity for water vapor of less than 5wt% at 25°C and P/Pg of 0.1, and a specific surface area of 600-850m^/g; and said amorphous silica-alumina has a SiO2content o±15-5Qwt%, a specific surface area of 300-600m2/g, a pore volume of 0.8-1. 5ml/g and an IR acidity of 0.25-0.60mmol/g.
The hydrogenation metals used in the catalyst of the present invention are preferably selected from the group consisting of Groups VIB and VIII metals, more preferably Mo and/or W, and Co and/or Ni. And the metal components are preferably metal oxides, most preferably molybdenum oxide and/or tungsten oxide, cobalt oxide and/or nickelous oxide.
The catalyst according to the invention has a specific surface area of 180-300m2/g, preferably 200-250m2/g; and a pore volume of 0 .25-0.45ml/g, preferably 0.3-0.4ml/g.
The catalyst according to the present invention preferably

comprises a Group VIB metal component (calculated as oxide(s)) of 10-40wt%, a Group VIII metal component (calculated as oxide (s) ) of l-20wt%, an ultra-hydrophobic zeolite-Y of S-"IOwtyo, an amorphous silica-alumina of 10-70wt%, and a binder of 0-40wt%.
The catalyst according to the present Invention more preferably comprises a Group VIB metal component (calculated as oxide(s)) of 10-35wt%, a Group VIII metal component (calculated as oxide (s)) of l-15wt%, an ultra-hydrophobic zeolite-Y of 5-35wt%, an amorphous silica-alumina of 10-60wt%; and a binder of 5-35wt%.
The catalyst according to the present Invention most preferably comprises a Group VIB metal component (calculated as oxide(s)) of 15-30wt%, a Group VIII metal component (calculated as oxide (s)) of 2-10wt%, an ultra-hydrophoblc zeollte-Y of 10-30wt%, an amorphous silica-alumina of 15-50wt% and a binder of 10-30wt%.
The catalyst according to the present invention most preferably comprises Group VIB metal oxide (s) of 18-28wt%, Grout: VIII metal oxide (s) of 4-8wt%, a ultra-hydrophobic zeolite-Y of 10-25wt%, a specific amorphous silica-alumina of 20-40wt%, and a binder (calculated as dry alumina) of 15-30wt%.
The ultra-hydrophoblc zeollte-Y used In the catalyst according to the Invention has a SI02/AI2O3 molar ratio of 5-25, an IR acidity of 0.2-0.6mmol/g and a sorptive capacity for water vapor of less than 5wt% at 25C and P/Po of 0.1. Preferably, said ultra-hydrophobic zeolite-Y has a Sioz/AbOa molar ratio of 6.0-17; an appropriate proportion of non-skeletal alumina, which accounts for 10-50wt% based on the total weight of alumina contained in the zeolite; a very narrow range of crystal unit cell size, generally between 2.420 and 2.445nm, most preferably between 2.425 and 2. 435nm. The ultra-hydrophobic zeollte-Y according to the present invention has obviously secondary pores,that Is, the modified zeollte-Y has an Increased number of medium pores, accompanied by the increase in specific sur^ce area and pore volume. Said zeoiite-Y has a specific surface area of

600-850m2/g, preferably700-800m2/gj a pore volume of 0.2-0.6ml/g, preferably 0.3-0.5m!/g, with more than 50% of the total pore volume being contributed by the secondary pores having diameters of over 2nm; and an IR acidity of preferably 0.3-0.5mmol/g.
The amorphous silica-alumina used in the catalyst according to \ht invention has a Si02 content of 10-50wt%; a specific surface area of 300-600mVg, a pore volume of 0.8-l.Sml/gandanlRacidity of 0.25-0.&0mmol/g. Preferably, said amorphous silica-alumina is one v;hlch has a SiO^ content of 15-50wt%, preferably 20-40wt%, a specific surface area of 350-550mVg, preferably 400-SOOnf/g; a pore volume of Q.9-1.4ml/g, preferably 1.0-1.3ml/g, and an IR .acidity of 0.30-0.55mmol/g, preferably 0.35-0.50mmol/g.
The amorphous silica-alumina according to the present invention may optionally contain phosphorus, preferably of l-5wt% calculated as P2O5
A binder is preferably used in the catalyst of the present invention, which is preferably an alumina binder and most preferably a small pore alumina which is peptized with nitric acid and has a specific surface area of 240-280mVg and a pore volume of 0.4-0.5ml/g,
The catalyst of the present invention can be prepared by mixing the above mentioned amorphous silica-alumina of IO-50wt%, the above mentioned ultra-hydrophoblc zeolite-Y of 5-40wt%, and optionally adding a binder, kneading, rolling and pressing the blend into block mass, and extrusion moulding the block mass by an extruder into carrier bars ; and then supporting active hydrogenation metals onto said carrier by a conventional method such as impregnation to obtain the catalyst of the Invention.
The moulded carrier bars may be in any suitable shape, for example, a cylindrical shape having a diameter of 1.2-1.8mm, or be in the specific shapes, such as those of clover or four-leaf clover. Before supporting active hydrogenation metals onto the carrier, the moulded carrier bars can be dried at a temperature of 90-160.C, preferably IIC-140"C for 6-12 hours, preferably 8-10 hours, and activated by calcination at a temperature of 400-650°C, preferably 450-600°C for 1-10 hours, preferably 3-6 hours to obtain the carriers ready for use.

The ultra-hydrophobic zeolite-Y according to the invention may be prepared in the following steps:
(1) preparing a zeolite-Y (I) having a Na2O content of less
than 0.2wt%;
(2) adding the zeolite-Y to a high-temperature calcining oven,
calcining at 450-700°C and under a pressure of 0.01-l.OMPa of
water vapor produced on-site or additonally introduced, for
0 . 5-10 hours to obtain an ultra-hydrophobic zeolite-Y (II) having
a SiOj/AljOj molar ratio of 5.2-6.0.
The ultra-hydrophobic zeolite-Y obtained according to the above steps may be further dealuminized selectively by a chemical method to obtain an ultra-hydrophobic zeolite-Y having a SiOj/AljOj molar ratio of 6.5-25. The chemical method for the selective dealuminization is carried out to remove selectively the non-skeletal alumina in the zeolite with a solution of an acid, such as hydrochloric acid, nitric acid, acetic acid, oxalic acid and the like, or of an organic complexing agent, such as acetylacetone, ETDA and the like.
And the zeolite-Y having a Na2O content of less than 0.2wt% can be prepared according to the following methods of (a) or (b) :
(a) stirring a commercial zeolite NaY as starting material in an ammonium ion-exchanging solution having a concentration of 1.0-5.OM, preferably 2.0-3.OM, in which the concentration of the zeolite NaY is 0.05-1.Og/ml, preferably 0.1-0.5g/ml, at a temperature of 70-150°C, preferably 80-120°C, for 0.5-3 hours, and repeating the above ion-exchanging step again and again till a zeolite-Y having a NajO content of less than 0 . 2wt% is obtained; or
(b) ion-exchanging a commercial starting material zeolite NaY according to the same ion-exchanging method as mentioned in
(a) for 2-3 times to obtain the zeolite-Y product (I) having a Na20 content of less than 3.0wt%, which is then hydrothermally treated at 450-600°C and under a vapor pressure of 0.01-0.2MPa for 0.5-3 hours; then ion-exchanging the resulting zeolite-Y by the same ion-exchanging method as mentioned in (a) for 2-3 times to obtain the zeolite-Y having a NazO content of less than 0 . 2wt%.

The amorphous silica-alumina according to the invention can be prepared by the following steps:
(a) adding an acidic aluminum salt solution and a basic precipitant simultaneously to a reaction vessel containing a smali amount of deionized water and carrying out the neutralization reaction at a pH value of 6.0-10.0 and a temperature of 50-80° C for 0.5-2 hours to form a sol;
(b) stabilizing the resulting sol from step (a) at pH 6-9 for 0-60 minutes;
(c) adding a silicon compound within 5-10 minutes to the resulting sol from step
(b);
(d) aging the mixture from step (c) at pH 7.5-9.5 and a temperature of 50-70°C for 10-60 minutes;
(e) filtering and washing the resultant from step (d); and
(f) dr/ing the material from step (e) at 90-120°C and crushing it to obtain the final product amorphous silica-alumina.
The acidic aluminum salt used in step (a) is one or more salts selected from the group consisting of aluminum sulfate, aluminum chloride and aluminum nitrate, and the basic precipitant is one or more compounds selected from the group consisting of sodium alumlnate, aqueous ammonia and sodium hydroxide.
The silicon compound used in step (c) can be waterglass or a silica sol or other silicon compounds of industrial grade.
The amorphous silica-alumina containing phosphorus can be obtained by slurrying the resultant from step (e), adding a proper amount of phosphorus compound such as phosphoric acid or other compounds containing phosphorus so that the product contains l-5w% P2O5 based on the total weight of the amorphous silicaalumina product, then filtering, drying and crashing to give the product containing phosphorus.
The hydrocracking catalyst according to the prwent Invention Is characterized In that it comprises a modified zeolite-Y and a specific amorphous silica-alumina. The modified zeoiite-Y used in the catalyst according to the invention has an increased molar ratio of SiOi/AlzOa and a further decreased amount of solid acid. After deeply dealuminized, said modified zeolite-Y has a decreased number of acid sites, and a decreased IR acidity of 0.2-0.6 mmol/g, preferably 0.3-0.5 mmol/g. Compared with the zeollte-Y prepared by the prior art, the zeolite used in the catalyst according to the present Invention has a larger specific surface area, and an added number of weak and moderate acid sites being formed with most of them being weak, and moderate acid sites desorbed at a temperature ranging from 160 to 450C and the strong

acid sites desorbed at >450°C being less than 25% (that is, after modified, the acid sites of the zcolite-Y have been decreased very much, but tiie strong acid sites have not been vanished compietety) , thus ensuring that no over cracldng wiil occur, while a certain amount of strong add sites can also ensure adequate cracldng activity of the catalyst. The properties of pores, including the larger specific surface area and more secondary pores, shown in the modified zeolite used In the catalyst according to the invention enhance efficiently the hydrogenatlon activity which Is advantageous to the Increase in the activity of the ring-opening reaction of multi-ring aromatlcs or heterocyclics containing nitrogen, and provide more efficient reaction space to meet the requirements of the mid-distillate type hydrocracking catalyst for moderate cracking activity and high hydrogenatlon activity for cracking heavy hydrocarbon materials.
The amorphous silica-alumina of the prior art has relatively small specific surface area and pore volume with the specific surface area being not more than 300mV0/ so when used as the carrier of the catalyst, It needs generally to be used in combination with Y -AI2O3 to support a large amount of metal components. The preparation process of the amorphous silicaaiumina used in the catalyst according to the present invention is characterized In that the formation of undesirable pore structure under the tendency of crystallization is avoided, thus ensuring the effective interaction of silicon and aluminum atoms to provide acid sites as well as a large specific surface area and large pore volume. The amorphous silica-alumina can have a pore volume of 0.8-1.5ml/g, and can still have a large specific surface area and large pore volume even in a very wide range of high SIO2 content. For example, when the SIO2 content Is 45% , the specific surface area can stiil be within the range of this invention. A large specific surface area makes the amorphous silica-alumina capable of supporting a large amount of metal components for hydrogenation, while the ackl sites can provide it with the cracking activity. The large pore volume is beneficial for easy movement of the reactants and products in and out of the cavities of the catalyst, and thus minimizing the opportunity of secondary

cracking reaction, while less carbon deposition wilt prolong the service life of the catalyst.
The ultra-hydrophobic zeolite-Y mentioned above Is used as a main acidic component of the hydrocracWng catalyst of the Invention. The addle property of the zeolite will provide the catalyst with relatively moderate cracking activity; the large specific surface area and secondary pore structure will improve the dispersion of hydrogenation metals to give full play to the hydrogenation activity, and improve the pore distribution in the catalyst, thus being of benefit to cracking oil distillates. In addition, the amorphous silica-alumina according to the invention is used as a supplement acidic component and a main carrier component of the catalyst, so It has a dual-function, for supplementing the acidic cracking function and serving as a main carrier component for supporting the hydrogenation metals. Said amorphous slllca-aiumina has appropriate acidity and acid strength ard can provide relatively moderate cracking activity when matched with the zeolite.
Therefore, compared with the mid-distillate type hydrocracking catalyst prepared by the prior art, the mid-distillate type hydrocracking catalyst according to the present invention has the features of higher activity and obviously higher mid distillate selectivity. Compared with the reference catalysts, the catalyst of the present Invention exhibits better activity and mid-dlstlllate selectivity In treating the same vacuum gas oils (VGO) under the same conditions.
The preparation process of the catalyst according to the present invention is simple and convenient, easy to operate and suitable for industrial production. The catalyst according to the present invention is designed for use in hydrocracldng process to produce middle distillates. In particular, the catalyst according to the invention is suitable for treating

heavy hydrocarbon materials having a distillation range of 250-600®C, generally 300-550C, for example, gas oils, vacuum gas oil distillates, deasphaited oils, cycle oils of FCC, shale oil, coal tars and the tike. The hydrocracking reaction according to the invention is generally carried out at a temperature of S"W) -420°C in the presence of hydrogen under a pressure of 5-30MPa, with the H/oil ratio being 100-5000 and the space velocity being O.l-5.0h-l. When the catalyst of the Invention (s used for treating conventional VGO, the hydrocracking reaction Is generally carried out at a temperature of 370-410**C in the presence of hydrogen under a pressure of preferably 10-20MPa with the H/oil ratio being 500-2000 and the space velocity being 0.5-1.5h-^
EXAMPLES
The present invention is further illustrated in detail with reference to the following examples which are provided for purposes of illustration and shall not be construed as limiting the present invention.
Example i
This example relates to the ultra-hydrophobic zeolite-Y (No. A) to be used in the catalyst according to the invention. (1) To an IM" Ion-exchanging vessel witti enamel inner-lining, 130kg NH4NO3 (product of industrial grade with a purity of > 99.5%, available from the Dalian Chemical Factory) and 800L Industrially purified water were added to prepare a 2M NH4NO3 solution, then the solution was heated to 70"C, 120kg zeolite NaY (50wt% calculated as dry basis, product available from the Wenzhou Catalyst Factory) was added, and ion-exchanged with stirring at 70°C for 3 hours. This exchanging step was repeated for 12 times. Then, the resulting mixture was filtered and washed with water to neutrality^ and dried to obtain the zeolite-Y having a NaaO content of 0.18 %. (2) The washed and dried zeolite obtained above was placed in a high pressure rotary oven, with the temperature being rapidly raised to 650°C and calcined under a pressure of 0.4MPa In the presence of 100% water vapor for 6 hours to obtain the ultra-hydrophobic zeolite-Y (No. A) to be used in tiie catalyst according to the invention. The physical and chemical properties of the zeolite are shown in Table 1.

Example 2
This example relates to the ultra-hydrophobic zeolite-Y (No B) to be used in the catalyst according to the invention. (1) 5.0kg of zeolite IMaY (the same as that in Example 1) was added to 50 liters of the 2M NH4NO3 solution, and ion-exchanged at 100**C with stirring for 2 hours for two times, then the resulting mixture was filtered, washed to neutrality, and dried to obtain, the product (I) ; (2) the product (I) was placed in the highpressure rotary oven and calcined at 550°C under a pressure of O.lMPa in the presence of 100% water vapor for 2 hours to obtain the produd: (II) ; (3) the product (II) was added to 50 liters of the 2M NH4NO3 solution, then ion-exchanged with stirring at 100°C for 2 hours for three times, and then filtered and washed with water to neutrality, and dried to obtain the product (III); (4) the product (III) was placed In a high pressure rotary oven and calcined at 550C under a pressure of 0.2MPa In the presence of 100% water vapor for 4 hours to obtain the ultra-hydrophobic zeollte-Y (No. B) to be used in the catalyst according to the invention. The physical and chemical properties of the zeolite are shown in Table 1.
Example 3
This example relates to the ultra-hydrophobic zeollteY (No. Q to be used in the catalyst according to the Invention, (1) 2.0kg of zeolite NaY (the same as that m Example 1) was added tx) 160 liters of the 3M NH4NO3 solution, and ion-exchanged at ISO** C with Stirring for 0.5 hour for 12 times to obtain the zeolite-Y with a NaiO content of 0.1 7wt%, then dried to obtain tlie product (I) ; (2) the product (I) was placed in a high pressure rotary oven and calcined at 700^C under a pressure of O.lMPa in the presence of 100% water vapor for 4 hours to obtain the product (II) ; (3) 400g of the product (II) was added to 4 liters of 0.4M hydrochloric acid solution and treated for 2 hours, then filtered and washed to neutrality, and dried to obtain the ultra-hydrophobic zeollte-Y (No. C) to be used in the catalyst according to the Invention. The physical and chemical properties of the zeolite are shown In Table 1.

Example 4
This example relates to the ultra-hydrophobic zeolite-Y (No. D) to be used in the catalyst according to the invention. lOOg ultra-hydrophobic zeolite-Y (No. A) from Example 1 was added to 1 liter of the 0 . 4M acetylacetone solution and treated for 2 hours, then filtered and washed with 3 liters of deionized water, then dried to obtain the ultra-hydrophobic zeolite-Y (No. D) to be used in the catalyst according to the invention. The physical and chemical properties of the zeolite are shown in Table 1.

Example 5
This example relates to the amorphous silica-alumina product S-1 to be used in the catalyst according to the invention. 3.2 liters of a concentrated solution of industrial aluminum sulfate was added to 4.2 liters of distilled water and heated with stirring to obtain an aluminum sulfate solution (al) having a concentration of Al3O3 of 6g/100ml. A concentrated aqueous ammonia was diluted with appropriate volume of distilled water to obtain a dilute ammonia solution (b) having a concentration of about 10%. 5 liters of distilled water was added to 2.4 liters of industrial water-glass having a concentration of 3.0 module to obtain a dilute water-glass solution (c) . To a lOL steel

reaction vessel, 2 liters of distitied water was added and heated with stirring to 70^C, then a neutralization reaction was carried out by turning on simultaneously the valves of vessels containing the aluminum sulfate solution and the ammonia solution respectively v/ith the flow of (al) being set at a given rate to keep pace with the neutralization reaction which was required to be carried on for 40 minutes to provide 600 g of the amorphous slllca-alumlna product, the flow of (b) being adjusted promptly to maintain the pH value in the system at 9.0, and the temperature in the reaction system being controlled at 55C. After the reaction of aluminum sulfate was completed, feeding of the ammonia liquor was stopped. The resulting alumina sol was stabilized for 30 minutes, then 1.4 liters (calculated amount) of (c) was added over 10 m"muHxis. The mixture was aged at 60°C for 30 minutes with the pH value being maintained at about 9.0. Then, the colloidal solution was filtered, and the resultant wet filter cake was pulped and washed with distilled water, and the resulting slurry was filtered to obtain filter cake(d), which was dried at 110*C for 8 hours, and crushed and screened to obtain the amorphous silica-alumina product S-1 to be used in the catalyst according to the invention.
Exampi« 6
This example relates to the amorphous silica-alumina product S-2 to be used in the catalyst according to the invention, 3.5 liters of a concentrated solution of industrial aluminum nitrate was added to 4.0 liters of distilled water and heated with stirring until completely dissolved to obtain an aluminum sulfate solution (a2) having a concentration of AI2O3 of 8g/100ml. A concentrated aqueous ammonia was diluted with an appropriate volume of distilled water to obtain a dilute ammonia solution (b) having a concentration of about 10%. To a lOL steel reaction vessel, 2 liters of distilled water was added and heated with stirring to 70PC, then the neutralization reaction was carried out by turning on simultaneously the valves of vessels containing the aluminum nitrate solution and ammonia solution respectively with the flow of (a2) being set at a given rate to keep pace with the neutralization reaction which was required to be carried on for 1.5 hours to provide 600 g of the amorphous silica-alumina

product, the flow of (b) being adjusted promptly to maintain the pH value in the system at 8.5, and the temperature in the reaction system being controlled at 55°C. After the reaction of aluminum nitrate was completed, feeding of the ammonia liquor was stopped. The resulting alumina sol was stabilized for 15 minutes, then 6.2 liters (calculated in accordance with the desired content of SIO2 in the final product) of (c) from Example 5 was added over 5 minutes. Tlie mixture was aged at 65°C for 15 minutes with the pH value being maintained at 8.5. Then, the colloidal solution was filtered, and the resultant wet filter cake was pulped and washed with distilled water, and the resulting slurry was filtered to obtain filter cake (d), which was pulped again, and 31.5 ml of phosphoric acid was added to the slurry s^nd stirred continuously for 30 minutes, and filtered to obtain the filter cake (e), which was dried at 110°C for 8 hours, crushed and screened to obtain the amorphous slllca-alumina product S-2 to be used in the catalyst according to the invention.
Example 7
This example relates to the amorphous silica-alumina product S-3 to be used in the catalyst according to the invention. A concentrated solution of industrial sodium alumlnate was added to 5.0 liters of distilled water and heated with stirring until homogeneously mixed to obtain a sodium alumlnate solution (a3) having a concentration of AI2O3 of 18g/100ml. An industrial AI2 (504)3 solution was diluted with an appropriate volume of distilled water to give an AI2 (S04)3 solution (b) having a concentration of 4g/100 ml. To a lOL steel reaction vessel, 2 liters of distilled water was added and heated with stirring to 70^C, then the neutralization reaction was carried out by turning on simultaneously the valves of vessels containing aluminum sulfate solution and sodium alumlnate solution respectively with the flow of (a3) being set at a given rate to keep pace with the neutralization reaction which was required to be carried on for 1 hour to provide 600 g of the amorphous slllca-alumina product, the flow of (b) being adjusted promptly to maintain the pH value in the system at 8.0, and the temperature in reaction system being controlled at 60^C. After the reaction was completed, the resulting alumina sol was stabilized for 40 minutes, then 3.3

liters (calculated in accordance with the desired content of SiO2 in the final product) of (c) from Example 5 was added over 10 minutes. The mixture was aged at 50°C for 40 minutes with the pH value being maintained at 8.5. Then, the colloidal solution was filtered, and the resulting wet filter cake was pulped and washed with distilled water, and the resulting slurry was filtered again to obtain filter cake (d) , which was dried at 110°C for 8 hours, and crushed and screened to obtain the amorphous silica-alumina product S-3 to be used in the catalyst according to the invention.
Example 8
This example relates to the amorphous silica-alumina product S-4 to be used in the catalyst according to the invention. 3 liters of a concentrated solution of aluminum chloride was added to 4.0 liters of distilled water and heated with stirring until homogeneously mixed to obtain the aluminum chloride solution (a4) having a corresponding AI2O3 concentration of 4g/100ml. A concentrated aqueous ammonia was diluted with an appropriate volume of distilled water to obtain a dilute ammonia solution (b) having a concentration of about 10%. To a lOL steel reaction vessel, 2 liters of distilled water was added and heated with stirring to 70°C, then the neutralization reaction was carried out by turning on simultaneously the valves of vessels containing aluminum chloride solution and ammonia solution respectively with the flow of (a4) being set at a given rate to keep pace with the neutralization reaction which was required to be carried on for 40 minutes to provide 600 g of the amorphous silica-alumina product, the flow of (b) being adjusted promptly to maintain the pH value in the system at 9.0, and the temperature in reaction system being controlled at 55°C. After the reaction of aluminum chloride was completed, the feeding of ammonia solution was stopped. The resulting alumina sol was stabilized for 30 minutes, then 2.0 liters (calculated in accordance with the desired content of SiO2 in the final product) of (c) from Example 5 was added over 10 minutes. The mixture was aged at 60°C for 30 minutes with the pH value being maintained at 9.0. Then, the colloidal solution was filtered, and the resulting wet filter cake was pulped and washed with distilled water, and the resulting slurry was filtered again to obtain filter cake(d), which was dried at

This example relates to the carrier SA and the catalyst (Cat .A) according to the invention. 102.5 g of the amorphous silicaaiumina product S-1 from Example 5 according to the invention and 60.5 g of the zeolite-Y (No. C) from Example 3 according to the invention were weighed and mixed homogeneously, then 250g of a jelly binder prepared by peptizing the small pore alumina having a pore volume of 0,42ml/g with nitric acid was added to the resulting mixture, rolled and pressed into mass, and extruded by an extruder into bars, which were dried at 110°C for 10 hours and activated at 500°C for 4 hours to obtain the carrier SA, which was Impregnated In a co-Impregnation solution containing W and Ni so that the catalyst finally contained 7wt% nickel oxide and 22 wt% tungsten oxide, then the Impregnated carrier was dried at 110°C for 12 hours and activated at SOO^"C for 3 hours to obtain the catalyst Cat.A.
Example 10
This example relates to the carrier SB and the catalyst (Cat. B:) according to the invention. 126.5 g of the amorphous silicaaiumina product S-2 from Example 6 according to the invention and 30.5 g of the zeotite-Y (No. C) from Example 3 according to the invention were weighed and mixed homogeneously, then 250g of a jelly binder prepared by peptizing the small pore alumina having a pore volume of 0.42m!/g with nitric acid was added to the resulting mixture, rolled and pressed Into mass, and extruded

by an extruder into bars, which were dried at 100ac for 11 hours and activated at 500C for 4 hours to obtain the carrier SB, which was impregnated in a co-impregnation solution containing W and Ni so that the catalyst finally containing 7wt% of nicicei oxide and 22wt% of tungsten oxide, then the impregnated carrier was dried at 110C for 12 hours and activated at 500C for 3 hours to obtain the catalyst CatB.
Comparative Example 1
This comparative example relates to the reference carrier SC and reference catalyst Cat.C. 104.8 g of the silica-alumlna having a spedfk: surface arm of 280m^/g, a pore volume of 0.76ml/g and a S1O: content of 35wt% (an industrial silica-alumina product manufactured by the Catalyst Factory of the Fushun Petro¬chemical Corporation) and 30.5g of the zeolite-Y component which was the same as that in Example 10 were weighed and mixed homogeneously, then 250g of a jally binder prepared by peptizing the small pore alumina having a pore volume of 0.42ml/g with nitric acid was added to the resulting mbcture, roiled and pressed into mass, an(^ extruded l7y an extruder into bars, which were dried and activated to obtain the carrier 3C. 60g of the carrier SC was saturatediy impregnated in 48ml of a co-impregnab"cn. solution containing W and Ni, then the impregnated carrier was dried and activated to obtain the reference catalyst Cat. C. The conditions for drying and activation were the same as those in Example 9.
Comparative Example 2
The comparative Example 2 relates to the reference canler SD and reference catalyst Cat.D. 28.9 of the zeolite-Y having of a molar ratio of SKVAIzOa) of 12, an m acidity of 0.94mmol/g (manufactured by the Catalyst Factory of the Fushun Petro¬chemical Corporation) and 126.5 g of the silica-alumina which was the same as that in Example 10 were weighed and mixed homogeneously, then 250g of a jelly binder prepared by peptizing the small pore alumina havbig a pore volume of 0.42ml/g with nitric acid was added to the resulting mixture, rolled and pressed into mass, and extruded by an exbuder into bars, which were dried and activated to ot^ln the canler SD. 60g of the carrier SD was saturatediy Impregnated In 46ml of a co-Impregnation solution

containing W and Ni, then the impregnated carrier was dried and activated to obtain the reference catalyst Cat.D. The conditions for drying and activation were the same as those in Example 9.
Example 11
This example relates to the carrier SE and the catalyst (Cat. E) according to the invention. 128.6 g of the amorphous silica-alumina product S-2 from Example 6 according to the invention and 11.1 g of the zeolite-Y (No. B) from Example 2 according to the invention were weighed and mixed homogeneously, then 250g of a binder prepared by peptizing 71. 4g of the small pore alumina having a pore volume of 0 .42ml/g with dilute nitric acid was added to the resulting mixture, rolled and pressed into mass, and extruded by an extruder into bars, which were dried at 110°C for 10 hours and activated at 500°C for 4 hours to obtain the carrier SE, which was impregnated in a co-impregnation solution containing Mo and Ni, then the impregnated carrier was dried at 110C for 12 hours and activated at 500"C for 3 hours to obtain the catalyst Cat.E, which finally consisted of silica-alumina of 45wt%, zeolite of 5wt%, alumina of 25wt%, nickelous oxide of 5wt% and molybdenum oxide of 20wt%.
Example 12
This example relates to the carrier SF and the catalyst (Cat. F) according to the invention. 88 . 7g of the amorphous silica-alumina product S-4 from Example 8 according to the invention and 45.4g of the zeolite-Y from Example 1 according to the invention were weighed and mixed homogeneously, then 222g of a binder prepared by peptizing 57 . Ig of the small pore alumina having a pore volume of 0.42ml/g with dilute nitric acid was added to the resulting mixture, rolled and pressed into mass, and extruded by an extruder into bars, which were dried at 110°C for 10 hours and activated at 500 °C for 4 hours to obtain the carrier SF, which was impregnated in a co-impregnation solution containing W and Ni, then the impregnated carrier was dried at 110°C for 12 hours and activated at 500°C for 3 hours to obtain the catalyst Cat.F, which finally consisted of silica-alumina of 30wt%, zeolite of 20wt%, alumina of 2 0wt%, nickelous oxide of 7.5wt% and tungsten oxide of 22.5wt%.

Example 13
This example relates to the carrier 8G and the catalyst (Cat. G) according to the Invention. 64.7g of the amorphous silica-alumina product S-1 from Example 5 according to the Invention and 60.5g of the zeollte-Y from Example 4 (NO.D) according to the invention were weighed and mixed homogeneously, then 167g of a bindo- prepared by peptizing 42.0g of the small pore alumina having a pore volume of 0. 42ml/g witH dilute nitric add was added to the resulting mixture, rolled and pressed into mass, and extruded by an extruder into bars, which were dried at UO.C for 10 hours and activated at 500°C for 4 hours to obtain the carrier SG, which was impregnated in a co-impregnation solution containing W and Ni, then the impregnated canler was dried at llO^C for 12 hours and activated at 500C for 3 hours to obtain the catalyst Cat.G, which finally consisted of slUca-alumlna of 20wt%, zeolite of_30wt%, alumina of 15wt%, nickelous oxide of 7.5wt% and tungsten oxide of 22.5wt%.
Example 14
This example relates to the carrier SH and the catalyst (CatH) according to the invention. 184.6g of the amorphous silicaalumina product S-3 from Example 7 according to the invention and 89.8g of the zeolite-Y from Example 3 according to the invention were weighed and mixed homogeneously, then 310ml of 3.9vol% diluted nitric add solution was added to the-resulting mixture, rolled «id pressed into mass, and extruded by an extruder into bars, which were dried at llO^C for 10 hours and activated at SOO^C for 4 hours to obtain the catalyst Cat.H, which finally consisted of silica-alumina of 60wt%, zeolite of 40wt%, nickelous oxide of 7.5wt% and tungsten oxide of 2.5wt% at 500X for 4 hours
Comparative Example 3
This comparative example relates to the reference carrier SI. and the reference catalyst (Cat. I). The reference carrier mid the reference catalyst were prepared according to the same

procedure as described in Example 12 except that the amoiphous silica-alumina was substituted with a commercial silica-alumina (having a specific surface area of 280mVg and a pore volume of 0.76ml/g, available from the Catalyst Factory of the Fushun Research Institute of Petroleum and Petrochemicals, SINOPEC, the P. R. China). TTie final catalyst consisted of silica-alumina of 30wt%, zeolite of 20wt%r alumina of 20wt%, nickeious oxide of 7.5wt% and tungsten oxide of 22.5wt%.
Comparaitive Example 4
This comparative example relates to the reference canlcr S3 and the reference catalyst (Cat. J) . Tlie reference carrier and the reference catalyst were prepared according to the same procedure as described in Example 12 except that the zcofite was substituted with a commercial zeolite (having a SHO2/A1.2Q3 ratio of 12, IR acidity of O.94mmoi/g and a crystal unit cell size of

2.445nm, available from the Wenzhou Catalyst Factor/, the P. R. China) . The final catalyst consisted of silica-alumina of 30wt%, zeolite of 20wt%, alumina of 20wt%, nickelous oxi4e of 7.5wt% and tungsten oxide of 22.5wt%.
Comparative Example 5
This comparative example relates to the reference catayst (Cat. K) . The reference catalyst was a high and middle distillate type hydrocracking catalyst which was commercially avaibble from the international market and contained a zeolite component having properties of zeolite-Y, a silica-alumina, an alumina and supported hydrogenation tungsten and nickel component. All the catalysts according to the invention and the reference catalysts were evaluated for their perfermances. The evaluation was carried out with Shengli VGO as the feed oil under a pressure of 14MPa, a Hz/dl volume ratio of 1500 and a space velocity of 1. 5h-1. Main properties are shown in Table 4. The evaluation for tiie catalyst activity was measured by comparing the reaction temperatures at which the same converskm could be achieved using the tested catalyst in once-through process, and the evaluation of the catalyst for mkl-distillate sdectivity was carried out according to the product distributions at a given conversion, in which the mid-distillate selectivity was calculated as the ratio of the yiek) of mkklle distillates to the total yiekl of the products having a distillation range below 370C.
It can be seen from the data and the physicchemteal properties of the carriers and the catalysts shown in Table 3 that the carriers and catalysts from the comparative examples have smaller pore volume and lower specific surface area, which will undoubtedly affect the dispersion of metals and. their hydrogenation activity, and moreover, owing to the exceedingly strong acidity of the zeolite used in the comparative catalyst, no substantial improvement in the mkl-distillate selectivity of the catalysts is achieved. The evaluation results In Table 5 also show that when used for treating a heavy feed oil having high aromatic content and high dry point of distillation range with a conversk>n of not less than 65vol%, the catalysts of the present

We Claim
1. A hydrocracking catalyst for producing middle distillates; comprising hydrogenation metal components, a modified uitra-hydrophobic zeoUte-Y, a specific amorphoui siiica-alumina and optionally an alumina binder, wherein said zeolite-Y has a Si02/Al203} molar ratio of 5-25, a crystal unit cell size of 2.420-2.445nm, an tR acidity of O.2-0.6mmol/g, a sorptive capacity for water vapor of less than Swt% at 25"C and P/Po of 0.1, and a specific surface area of 600-850mVg; and said amorphous silica-alumina has a Si02 content of 10-50wt%, a specific surface area of 300-600m2/g, a pore volume of 0.8-1. 5ml/g and an IR addity of 025-0.60mmol/g.
2. A catalyst as claimed in daim I, who^n said hydrogenation metal compon^its are Groups VIB and VZn metal components.
3. A catalyst as claimed in claim 2, wherein said metal components are Groups VIB and vm metal oxides, such as molybdenum oxide and/or tungsten oxide, cobalt oxide and/or nickelous oxide.
4. A catalyst as claimed In daim I, wherein said catalyst has a specific surface area of 180-300mV9, and a pore volume of 0.25-0.45ml/g.
5. A catalyst as claimed in claim I, wherein said catalyst has a specific surface area of 200-250mVg, and a pore volume of 0.30-0.40ml/g.
6. A catalyst as dalmed In claim 2, wherein said catalyst comprises a Group VIB metal component (calculated as oxide (s)} of 10-40wt%, a Group vm meial component (calculated as oxide (s) ) of l-20wt%, an uHra-hydrophoblc zeolite-Y of 5-40wt%, an amorphous sllica-alumtna of 10-70wt%, and a lender of 0-40wt%.
7. A catalyst as claimed in claim 2, wherein said catalyst comprises a Group VIB metal component (calculated as oxlde(s)) of 10-35wt%, a Group Vm metal component (calculated as oxide (s))

of l-15wt%, an uitra-hydrophobic zedite-Y of 5-35MA%, an amorphous silica^lumina oF 10-60wt%, and a binder of 5-35wt%.
8. A catalyst as claimed In dalm 2, wherein said catalyst comprises a Group VIB metal component (calculated as oxlde(s)) of 15-30wt%, a Group vm metal component (cakuiated as oxide (s)) of 2-10wt%, an uitra-hydrophobic zeotite-Y of 10-30wt%, an amorphous silica-alumina of 15-50wt%, and a binder of 10-30wt%.
9. A catalyst as claimed in claim 2 or 3, wherein said catalyst comprises Group VIB metal oxide (s) of 18 -28wt%, Group vni metal oxideCs) of 4-8wt%, a uitra-hydrophobic zeoilte-Y of l0-25wt%, a specific amorphous silica-alumina of 20-40wt%, and a binder (calculated as dry alumina) of 15-30wt%.
10. A catalyst as claimed in claim 1, wherein said zeolite-Y has a Si02/Al2O3 molar ratio of 6.0-17, a crystal unit ceil size of 2.425-2.435nm, a spedfic surface area of 700-800m2/ and an IR acidity of 0.30-0.50mmol/g, with more than 50% of the total pore volume being contributed by the secondary pores having pore size of >"h\m.
11. A catalyst as claimed in claim 1, wherein said amorphous siilca-alumlna has a Si02 content of i5-50wt%, a specific surface area of 350-550m^ /g, a pore volume of 0.9-1. 4ml/g and an IR acidity of 0.30-0.55mmol/g.
12. A catalyst as claimed in claim 1, wherein said amorphous silica-alumina has a Si02 content of 20-40wt%, a specific surface area of 400-500mVg« a pore wlume of 1.0-1.3mi/g and an IR acidity of 0.35-0.50mmol/g.
13. A process for preparing a catalyst as claimed in claim 1, comprising the steps of mixing an amorphous siilca-alumlna of 10-50wt%, a modified uitra-hydrophobic zeolite-Y of 5-40wt%, and optionally adding a binder, ioieading, roHing, pressing and moulding into a carrier, and then supporting active hydrogenation metab onto said carrier to obtain the catalyst of the invention; wherein said zeoiite-Y has a Si02/Al2O3 molar ratio of 5-25, a

crystal unit cdl size of 2.420-2 .445nm, an IR addNy of 0.2^.6mmo^f a sorptive capacity for water vapour of less than 5w% at 25oC and P/Po of 0.i, and a spedHc surface area of 600-850 m2/g; and said amorphous silica-alumina has i SiOz content of 10-50wt%, a spacific surfacea arsa of 300-600mVgf a pore volume of Q,$-1.9nl/g and an IR acidity of 0.25-0.60mmol/g.
14. A process as claimed in daim 13, comprisina the step of adding 15-3(M% of a binder of small pore alumina peptized with nitric add, which has a spedflc surface area of 240-280mVg and a pore volume of O.Ht.SM/g.
15. A process as claimed in daim 13 or 14, wherein said zeolite-Y has a SiO2/AI2O3 molar ratio of 6.0-17, a crysfeil unit cdl size of 2.425-2.435nm, a spedflc surfioa area of 700-8002/g and mn IR acldtty of 030^.50mmol/g, wtth mora than 50% of the total pore volume being contributed by the secondary pores having a pore size of >2nm, and said amorphous sllicaalumina has a SIO2 content of 15-5(^vt%, a spedfle surface area of 350-550mVg/ a pore volume of 0.9-1.4ml/g and an IR addlty of 0.30-0.55mmoi/g.
16. A process as daimed in daim 15, wherein said amorphous silica-alumirHi has a SiOz content of 20-40wt%, a specific surface area of 400-500mVg/ a port volume of 1.0-1.3ml/g and an IR addity of 0.35-0.50mml/g.
17. A process as daimed in daim 13 or 14, wherein said hydrogenation metab comprise Groups VIB and vm metals.
16. A process as claimed in daim 13 or 14, wherdn said hydrogenation metals comprise Mo and/or W and Co and/or Nl.
19. A process as daimed in claim 13 or 14, wherein it comprises the following stsps for the preparation of said zeolite-Y:
(1) preparing a zeolite-Y having a Na2O content of less than 0.2wt%; and
(2) pladng said zeoiite-Y into a high-temperature caidntng oven, caldning at 450-700X and under a pressure of 0.01-1. OMPa

of water vapor produced on-site or additionally Introduoed, for 0.5*10 hours to obtain an ultra-hydrophobic zeolite-Y having a SiO2/A1zO3a motar ratio of 5.2"6.0.
20. A process at daimod in daim 19, wharain said ultrahydrophobic zeolite-Y it furfhar
dealuminized saiadjvaly to obtain an ultra-hydrophobic zaolita-Y having a
Si02/Ala03 molar ratio of 6.5-25.
21. A process as claimed in claim 13 or it, wherein it comprises the following
steps for the prqpantion of said amorphous silica-alumina:
(a) adding an acidic aluminum salt solution and a basic precipitant simuttaneousiy into a reaction vessel containing a small amount of delonlzed water and carrying out the neutralization reaction at a pH value of 6.0-10.0 and a temperature of 50-80°C for 0.5-2 hours to form a sol;
(b) stabilizlna the resultir^g sol from step (a) at a pH value of 6-9 for 0-60 minutes;
(c) adding a silicon compound into the resulting sol ft^m step (b);
(d) aging the mixture from step (c) at a pH value of 7.5-9.5 and a tenrperature of
50-70°C for 10-60 minutes;
(e) filtering and washing the resuttsnt from step (d) /end
(f) drying the rasuldng materiel from step (e) at 9O-13I0K; and crushing it to obtain
the prockict amorphous silicaalumina.
22. A process as claimed in daim 21 wherein said acidic aluminum salt is one or more salts selected from the group consisting of aluminum sulfate, aluminum chloride and aluminum nitrate, and said basic predpltant is one or more compounds sdected from the group consisting of sodium eiuminate, aqueous emmonia and sodium hydro)dde..

Documents:

1095-mas-1999 abstract-duplicate.pdf

1095-mas-1999 abstract.pdf

1095-mas-1999 claims-duplicate.pdf

1095-mas-1999 claims.pdf

1095-mas-1999 correspondence-others.pdf

1095-mas-1999 correspondence-po.pdf

1095-mas-1999 description (complete)-duplicate.pdf

1095-mas-1999 description (complete).pdf

1095-mas-1999 form-1.pdf

1095-mas-1999 form-13.pdf

1095-mas-1999 form-19.pdf

1095-mas-1999 form-26.pdf

1095-mas-1999 form-3.pdf

1095-mas-1999 form-5.pdf

1095-mas-1999 others.pdf

1095-mas-1999 petition.pdf

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Patent Number

216472

Indian Patent Application Number

1095/MAS/1999

PG Journal Number

13/2008

Publication Date

31-Mar-2008

Grant Date

13-Mar-2008

Date of Filing

11-Nov-1999

Name of Patentee

CHINA PETROCHEMICAL CORPORATION

Applicant Address

6A HUIXIN DONG STREET, CHAOYANG DISTRICT, BEIJING,

Inventors:

#	Inventor's Name	Inventor's Address
1	SONG CHEN	C/O FUSHUN RESEARCH INSTITUTE OF PETROLEUM AND PETROCHEMICALS, SINOPEC, 31 DANDONG ROAD, WANGHUA DISTRICT, FUSHUN, LIAONING PROVINCE,
2	TINGYN LI	C/O FUSHUN RESEARCH INSTITUTE OF PETROLEUM AND PETROCHEMICALS OF SINOPEC, 31 DANDONG ROAD, WANGHUA DISTRICT, FUSHUN, LIAONING PROVINCE,
3	GUANGWEI CAO	C/O FUSHUN RESEARCH INSTITUTE OF PETROLEUM AND PETROCHEMICALS OF SINOPEC, 31 DANDONG ROAD, WANGHUA DISTRICT, FUSHUN, LIAONING PROVINCE,
4	MINGHUA GUAN	C/O FUSHUN RESEARCH INSTITUTE OF PETROLEUM AND PETROCHEMICALS OF SINOPEC, 31 DANDONG ROAD, WANGHUA DISTRICT, FUSHUN, LIAONING PROVINCE

PCT International Classification Number

B10J 23/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	CN98114459.4	1998-11-13	China