KR20100014272A - Selective hydrocracking process using beta zeolite - Google Patents

Abstract

According to the invention an intermediate fraction product is obtained in increased yield in the hydrocracking process using a catalyst comprising beta zeolite. In embodiments, the beta zeolite is not hydrothermally treated or hydrothermally treated at relatively low temperatures. In another embodiment, the catalyst comprises a relatively small amount of beta zeolite.

Description

Selective Hydrocracking Method using Beta Zeolite {SELECTIVE HYDROCRACKING PROCESS USING BETA ZEOLITE}

The present invention is directed to a hydrocracking process that produces an increased amount of product in the middle fraction boiling range and uses a catalyst comprising beta zeolite as the active cracking component.

Hydrocracking is the basic conversion process used in many petroleum refineries worldwide to reduce the molecular weight of petroleum derived feedstocks and convert them into more valuable products such as motor fuels, diesel fuels and lubricants. Hydrocracking may also show other advantageous results, such as the removal of sulfur and nitrogen from the feedstock by hydrodesulfurization. While the overall physical design of the hydrocracking process can be very important for the conversion and selectivity realized by the hydrocracking process, these two performance measures are always related to the ability of the hydrocracking catalyst used in the process.

Hydrocracking catalysts are initially classified according to the properties of the main decomposition components of the catalyst. This classification divides the hydrocracking catalyst into a catalyst composed mainly of an amorphous decomposition component such as silica-alumina and a catalyst composed mainly of a zeolite decomposition component such as Y zeolite. Hydrocracking catalysts are also classified based on the intended main product, two main products of which are naphtha and distilled petroleum-derived oils having a higher boiling point range than naphtha in the field of hydrocracking refining. Water ". Distillates typically include products recovered in refineries as kerosene and diesel fuel. The process disclosed herein relates to a zeolite catalyst with improved selectivity for hydrocarbon products in the distillate boiling range. These catalysts usually comprise a zeolite component and a support or other components such as alumina or silica-alumina and a metal hydrogenation component.

US 4,757,041 discloses simultaneous hydrocracking and dewaxing of heavy oils using a catalyst comprising a zeolite beta and a second zeolite such as X or Y zeolite. U.S. 5,128,024 and U.S. 5,284,573 disclose a hydrocarbon conversion process which simultaneously performs hydrocracking and dewaxing on heavy oil using a catalyst based on a hydrogenation component and zeolite beta. Japanese Laid-Open Publication No. 11-156198, published on June 15, 1999, discloses a hydrocracking process for the production of intermediate fractions using a catalyst comprising bealuminized beta zeolite by acid treatment and subsequent hydrothermal treatment.

It has been found that intermediate fractional hydrocracking catalysts comprising beta zeolites having a silica: alumina mole ratio of less than 30: 1 and an SF ₆ adsorption capacity of at least 28% by weight have good selectivity and activity. It is not necessary to steam the beta zeolite, but it can be steamed. The catalyst comprises a metal hydrogenation component such as nickel, cobalt, tungsten, molybdenum or any combination thereof. Hydrogenation catalysts comprising the present beta zeolites are considered novel in the art. One embodiment of the process disclosed herein may be summarized as a hydrocracking process comprising contacting a feed stream comprising a hydrocarbon having a boiling point range of 340 ° C. to 565 ° C. with a catalyst comprising a hydrogenation component and a beta zeolite. Hydrogenation components include metal components such as nickel, cobalt, tungsten, molybdenum or any combination. Beta zeolites have a silica: alumina molar ratio of less than 30: 1 and an SF ₆ adsorption capacity of at least 28% by weight.

The figure is a plot plotting the activity benefits expressed in reactor temperature as compared to the reference catalyst, yield yield of the catalyst tested compared to the reference catalyst.

details

The relative value of different products of petroleum refineries is determined by various factors, including climate and local consumption patterns. In some provinces it is economically advantageous to produce hydrocarbons in the naphtha boiling range. In other provinces it is better to produce heavier (higher boiling) diesel and kerosene fractions. The product distribution obtained from existing hydrocracking units can be adjusted to a limited range by varying feedstocks and operating conditions, but the yield characteristics of the catalysts used in this process are often high, although difficult to determine their importance. In many regions, the relative demand for distillate is growing faster than the demand for naphtha boiling hydrocarbons, and many refineries are trying to increase distillate production.

It is also very important to avoid full conversion of feedstock in the economics of refineries. Non-selective decomposition produces high proportions of unwanted low quality products such as C ₄ ^- hydrocarbons. Thus, the selectivity of the hydrocracking process has become very important in producing the desired distillate product. Thus, it is a continuing economic advantage to provide more selective catalysts. It is an object of the processes disclosed herein to provide active hydrocracking catalysts and methods that are selective for producing hydrocarbons in the distillate boiling range.

As set forth in the various references cited above, beta zeolites are known in the art as components of hydrocracking catalysts. Beta zeolites are disclosed in US 3,308,069 and US Re 28,341, which are incorporated herein for explanation of this material. The cited document also describes that hydrocracking conditions and procedures are widely disclosed in the literature. The zeolite beta used in the processes disclosed herein has a silica: alumina molar ratio (SiO ₂ : Al ₂ O ₃ ) of less than 30: 1 in one embodiment, less than 25: 1 in another embodiment, 9: 1 in another embodiment. More than 30: 1, in a 4th specific example, it is 9: 1 or more and less than 25: 1, in a 5th specific example, 20: 1 or more and less than 30: 1, and a 6th specific example are 15: 1 or more and less than 25: 1.

Beta zeolites are generally synthesized from a reaction mixture comprising a template. The use of template agents for the synthesis of beta zeolites is known in the art. For example, US 3,308,069 and US Re 28,341 disclose the use of tetraethylammonium hydroxide, and US 5,139,759, incorporated herein, discloses the use of tetraethylammonium ions derived from the corresponding tetraethylammonium halides. It is believed that the choice of specific template is not critical to the success of the process disclosed herein. In one embodiment, the beta zeolite is calcined in air at a temperature of 500-700 ° C. for a time sufficient to remove the template from the beta zeolite. Calcination for removing the template can be carried out before or after blending the beta zeolite with the carrier and / or the hydrogenation component. Although it is believed that the template can be removed at calcination temperatures of 700 ° C. or higher, too high calcination temperatures significantly reduce the SF ₆ adsorption capacity of the beta zeolite. For this reason, it is believed that when preparing beta zeolites for use in the processes disclosed herein, calcination temperatures of at least 750 ° C. to remove the template agent should be avoided. It is important for the process disclosed herein that the SF ₆ adsorption capacity of the beta zeolite is at least 28% by weight.

Hydrothermally treated zeolites for use in hydrocracking catalysts are known. However, steam treatment is a relatively insensitive tool. For any given zeolite, steam treatment reduces the acidity of the zeolite. When steam treated zeolites are used as hydrocracking catalysts, the obvious result is that the overall distillate yield increases but the catalyst activity decreases. This obvious conflict between yield and activity means that the zeolite should not be steamed to obtain high activity, but product yield is low instead. Obvious tradeoffs between overall distillate yield and activity should be considered and limit the improvements that can be obtained by steaming the zeolite. In comparison, the process disclosed herein focuses on using beta zeolites in hydrocracking catalysts in a manner that improves both activity and yield for intermediate fraction products.

The hydrocracking process disclosed herein centers on using a relatively small amount of zeolite beta with a relatively low silica: alumina molar ratio and a relatively high SF ₆ adsorption capacity. It has been found that other performance is obtained when such zeolite beta is introduced into the hydrocracking catalyst in this manner. Not only is the hydrocracking catalyst activity higher than the catalyst containing the vaporized beta zeolite, but also the product yield is unexpectedly high.

The catalysts used in the processes disclosed herein are primarily for use as replacement catalysts in existing commercial hydrocracking equipment. Thus, the size and shape is preferably similar to that of a conventional commercial catalyst. It is preferred to produce in the form of cylindrical extrudates having a diameter of 0.8 to 3.2 mm. However, the catalyst may be prepared in any other desired form, such as spherical or pelletized. The extrudate may be of a non-cylindrical shape, such as other well-known trilobal shapes or advantageous in terms of pressure drop or reduced diffusion distance.

Commercial hydrocracking catalysts include a number of non-zeolitic materials. This is due to several reasons such as particle strength, cost, porosity and performance. Thus, other catalyst components, although not as active decomposition components, make a positive contribution to the overall catalyst. Other components are referred to herein as carriers. Some typical carrier components, such as silica-alumina, typically contribute somewhat to the resolution of the catalyst. In one embodiment, the catalyst of the process disclosed herein comprises beta zeolite in a positive amount of less than 3% by weight based on the sum of the beta zeolite and the support on a volatile exclusion basis. The volatile exclusion criterion means that each of the beta zeolite and the support was heated at 500 ° C. to remove all volatiles, and then the respective weights were measured. Based on the sum of the beta zeolite and the carrier on the basis of volatile exclusion, the zeolite content of the catalyst used during the process disclosed herein is less than 2% by weight in another embodiment and 1.5% by weight in the third embodiment. It is an actual amount of less than, the actual amount of less than 1% by weight in the fourth embodiment, the actual amount of less than 0.5% by weight in the fifth embodiment, and the actual amount of 0.1 to 2% by weight in the sixth embodiment. The remainder of the catalyst particles other than the zeolitic material may consist primarily of conventional hydrocracking materials such as alumina and / or silica-alumina. The presence of silica-alumina helps to realize the desired performance characteristics of the catalyst. In one embodiment, the catalyst comprises at least 25 weight percent alumina and at least 25 weight percent silica-alumina based on the weight of the catalyst. In another embodiment, the silica-alumina content of the catalyst is at least 40% by weight and the alumina content of the catalyst is at least 35% by weight, both of which are based on the weight of the catalyst. However, alumina is believed to act only as a binder and not an active degradation component. The catalyst support may comprise at least 50% by weight silica-alumina or at least 50% by weight alumina based on the weight of the support. In one embodiment, approximately equal amounts of silica-alumina and alumina are used. In addition to silica-alumina and alumina, other inorganic refractory materials that can be used as carriers include, for example, silica, zirconia, titania, boria and zirconia-alumina. The carrier materials described above may be used alone or in any combination.

The catalyst includes metallic hydrogenation components in addition to beta zeolite and other carrier materials. The hydrogenation component is preferably provided as one or more base metals uniformly distributed in the catalyst particles. Although precious metals such as platinum and palladium can be applied, the best results have been obtained with a combination of the two base metals. Specifically, nickel or cobalt are paired with tungsten or molybdenum, respectively. Preferred compositions of the metal hydrogenation component are both nickel and tungsten, and the metal weight of the tungsten element is 2-3 times the amount of nickel. The amount of nickel or cobalt is preferably from 2 to 8% by weight of the final catalyst. The amount of tungsten or molybdenum is preferably 8 to 22% by weight of the final catalyst. The total amount of base metal hydrogenation component is 10 to 30% by weight.

Industry standard techniques can be used to formulate the catalyst of the process. This can be summed up very commonly as mixing beta zeolite with other inorganic oxide components and liquids such as water or weak acid to form an extrudable dough and then extruding it into a porous die plate. The extrudate is collected and preferably calcined at high temperature to cure the extrudate. Extruded particles are screened by size and hydrogenated components are added by dip impregnation or the well-known incipient wetness technique. If the catalyst contains two metals in the hydrogenation component, they can be added sequentially or simultaneously. The catalyst particles can be calcined again between the metal addition steps and after the metal is added. The final catalyst has a surface area of 300-550 m ² / g and an average bulk density (ABD) of 0.9-0.96 g / cc.

The hydrocracking process is carried out in a range of general conditions currently used commercially in the hydrocracking process. In many instances, the operating conditions are specific to the refinery or treatment apparatus. That is, these conditions are largely suggested by the construction and constraints of existing hydrocracking apparatus, the composition of the feed and the desired product, which usually cannot be changed without significant cost. The inlet temperature of the catalyst is in the range of 232 to 454 ° C. and the inlet pressure should be at least 6895 kPa (g). The feed stream is mixed with sufficient hydrogen to feed hydrogen at a circulation rate of 168-1684 nl / l and passed through one or more reactors comprising a fixed bed of catalyst. Hydrogen originates primarily from the recycle gas, which may pass through a purification plant for acid gas removal, but need not be so. The hydrogen rich gas mixed with the feed and in one embodiment any recycle hydrocarbon comprises at least 90 mol% hydrogen. In the case of distillate hydrocracking, the feed rate, expressed in liquid hourly space velocity (LHSV), is usually in the wide range of 0.3-1.5 hr ⁻¹ , in one embodiment LHSV of 1.2 or less is used.

A typical feed entering the process is a mixture of several different hydrocarbons and compounds boiling together from crude oil by fractional distillation. The feed generally has a boiling point range of at least 340 ° C., up to 482 ° C. in one embodiment, up to 540 ° C. in other embodiments, and up to 565 ° C. in a third embodiment. Such petroleum derived feeds may be a combination of streams produced in refineries, such as coker diesel, dc diesel, deasphalted diesel and reduced pressure diesel. Alternatively, the feed may be a single fraction, such as heavy vacuum gas oil. Synthetic hydrocarbon mixtures such as those recovered from shale oil or coal may be treated in this process. The feed may be treated by solvent extraction or hydrotreated and then passed through the process to remove the total amount of other contaminants such as sulfur, nitrogen or asphaltenes. The process is expected to convert most of the feed to more volatile hydrocarbons such as naphtha and diesel boiling range hydrocarbons. Typical conversion rates are highly dependent on feed composition and vary from 50 to 90 volume percent. In one embodiment of the process disclosed herein the conversion is 60-90% by volume, 70-90% by volume in other embodiments, 80-90% by volume in another embodiment, 65-75% by volume in another embodiment. Process effluents actually include a wide range of hydrocarbons, from methane to substantially unchanged feed hydrocarbons boiling at temperatures above the boiling range of any desired product. Hydrocarbons that boil at temperatures above the boiling point of any desired product are referred to as products that are not converted, even though their boiling points decrease to some extent in the process. Most of the unconverted hydrocarbons are recycled to the reaction zone and a small proportion, for example 5% by volume, is removed as drag stream.

Regardless of the conventional hydrotreatment, the catalyst can be used for those mentioned in the art in one and two stage process streams. These terms are described in Hydrocracking Science and Technology by J. Scherzer and A.J. Gruia, 1996, Marcel Dekker Inc., ISBN 0-8247-9760-4. In a two stage process, the catalyst can be used in the first stage or the second stage or both stages. The hydrotreating catalyst may be placed in a separate reactor prior to the catalytic treatment, or the catalyst may be loaded in the same reactor as the hydrotreating catalyst or a different hydrocracking catalyst. An upstream hydrotreatment catalyst can be used as a feed pretreatment step or for hydroprocessing the recycled unconverted material. Hydrotreatment catalysts can be used for special purposes to hydrotreat a compound to promote conversion of the multinuclear aromatic (PNA) compound on subsequent hydrocracking catalyst bed (s). The present catalyst can be used together with a second other catalyst such as a catalyst mainly composed of Y zeolite or a catalyst mainly having an amorphous decomposition component.

In some embodiments of the processes disclosed herein, the catalyst is used with the feed, or the feed through the catalyst is an untreated feed or used in a configuration similar to the untreated feed. The sulfur content of crude oil and thus the feeds introduced into the process are highly dependent on the source. As disclosed herein, the untreated feed still contains at least 1000 ppm by weight of sulfur, including the unhydrotreated feed or organic sulfur compounds, or 100 ppm by weight (0.01 weight) of nitrogen, still containing organic nitrogen compounds. It means more than the feed.

In another embodiment of the process disclosed herein, a catalyst is used with the hydrotreated feed. One skilled in the hydrocarbon processing art knows and can perform the hydrotreatment of an untreated feed to produce a hydrotreated feed for use in the processes disclosed herein. While the sulfur concentration in the feed may be 500-1000 ppm by weight, the sulfur concentration of the hydrotreated feed is less than 500 ppm by weight in one embodiment of the process disclosed herein and 5-500 ppm by weight in other embodiments. The nitrogen concentration of the hydrotreated feed is less than 100 ppm by weight in one embodiment and 1-100 ppm by weight in another embodiment.

Steam treatment of zeolites, such as beta zeolites, is known to actually cause changes in zeolite crystalline structure, but current analytical capabilities cannot accurately monitor and / or characterize changes in important structural details of zeolites. The situation is more complicated for beta zeolites compared to Y zeolites because there are nine different tetrahedral aluminum sites in beta zeolites but only one in Y zeolites. Instead, measured values of various physical properties of the zeolite such as surface area are used as indicators of the generated change and degree of change. For example, a decrease in the capacity of the zeolite to adsorb hexafluorosulfur (SF6) after steam treatment is thought to be due to a decrease in zeolite crystallinity or the size or accessibility of the zeolite micropores. However, because the SF6 adsorption capacity of the catalyst used in the process disclosed herein is relatively high, indirect correlation of zeolite changes may be undesirable. In one embodiment of the method disclosed herein, the SF6 adsorption capacity of the beta zeolite should be at least 28% by weight, whether or not it is steam treated.

In one embodiment of the process disclosed herein, the beta zeolite is not subjected to steam treatment, while in other embodiments of the process disclosed herein, the beta zeolite may be subjected to steam treatment, but such steam treatment is a vapor of beta zeolite referred to in the literature. Relatively mild compared to treatment. It has been found that steaming zeolite beta for a suitable time and under appropriate conditions may yield a catalyst that can be used in the process disclosed herein. In other words, as mentioned above, there is an obvious trade-off between activity and overall distillate yield, and thus may be a limitation to the improvements that appear to be obtainable by steam treatment of zeolites.

The steam treatment of beta zeolites can be carried out successfully in different ways, the actual commercially used method being greatly influenced and possibly determined by the performance and type of equipment available. Steam treatment can be carried out using a zeolite which is kept as a fixed amount or which is conveyed by a belt or stirred in a rotary kiln. Uniform treatment of all zeolite particles under appropriate time, temperature and vapor concentration conditions is an important factor. For example, zeolite should not be placed such that there is a significant difference in the amount of vapor in contact with the surface and inside of the zeolite mass. In one embodiment, the beta zeolite is steamed in an atmosphere with live steam passing through a device providing a low vapor concentration. It may be disclosed that the vapor concentration is a substantial amount of less than 50 mol%. The vapor concentration may be 1-20 mol% in one embodiment, 5-10 mol% in another embodiment, and may expand to higher concentrations in small laboratory operations. The steam treatment of one embodiment is carried out at atmospheric pressure of up to 600 ° C. and up to 5 mol% of actual vapor content for 1 hour or up to 2 hours of actual time or for 1 to 2 hours. The steam treatment of another embodiment is carried out for up to 2 hours of actual time at temperatures up to 650 ° C. and up to 10 mol% of actual vapor content at atmospheric pressure. The amount of steam is based on the weight of steam in contact with the zeolite beta. Steam treatment at temperatures above 650 ° C. appears to form zeolites that are not useful in the processes disclosed herein because the SF6 adsorption capacity of the resulting zeolite beta is too low. Temperatures of up to 650 ° C. may be used, and in one embodiment the steam treatment temperature may be between 600 and 650 ° C., in another embodiment less than 600 ° C. There is generally an interaction between steam treatment temperature and time, and increasing temperatures are known in the art to shorten the time required. However, in the case of steam treatment, for good results, it seems that in one embodiment, ½ to 2 hours, in other embodiments 1 to 1½ hours can be used. In one embodiment, the method of conducting steam treatment on a commercial scale is in a rotary kiln where steam is injected at a rate that maintains a 10 mol% steam atmosphere.

Beta zeolites of the processes disclosed herein are not treated with an acid solution which in one embodiment is dealuminated. In this regard, it is noted that exposure of substantially all untreated (as synthesized) zeolites to acids reduces the sodium concentration remaining from the synthesis. This step in the zeolite manufacturing process is not considered part of the zeolite treatment prepared as disclosed herein. In one embodiment, during the treatment and catalyst preparation procedures, the zeolite is exposed to the acid only during incidental production activities such as peptising during the formation process or during metal impregnation. In one embodiment, the zeolite is not acid washed after the steaming procedure to remove aluminum “fragments” from the pores.

An exemplary laboratory scale steam treatment procedure is performed with zeolites held in 6.4 cm quartz tubes in a clamshell furnace. The temperature of the furnace is gradually raised by the regulator. After the temperature of the zeolite reaches 150 ° C., steam formed from the deionized water contained in the flask is introduced into the lower portion of the quartz tube and passed upward. Other gases are passed through the tube to achieve the desired amount of vapor. Fill the flask as needed. In an exemplary procedure, the difference between the steam cutting time and the time the zeolite reaches 600 ° C. is 1 hour. At the end of the set steam period, the regulator is reset to 20 ° C. to lower the temperature of the furnace. The furnace is cooled to 400 ° C. (2 hours) and the steam flow to the quartz tube is stopped. The sample is taken out at 100 ° C. and placed in a laboratory oven overnight at 110 ° C. with air purging.

Beta zeolites of the processes disclosed herein can be characterized in terms of SF6 adsorptivity. This is a known technique for the characterization of microporous materials such as zeolites. This method is similar to other adsorption capacity measurement methods, such as the amount of water, in that a weight difference is used to measure the amount of SF6 adsorbed by a preheated sample so that it contains substantially no adsorbent material. SF6 is used in this test because its size and shape prevents the entry into pores less than 6 Angstroms in diameter. Thus, it can be used as a measure of available pore inlet and pore diameter reduction. This is also a measure of the effect of vapor treatment on zeolites. In a very simplified description of this method, the sample is preferably pre-dried and weighed in vacuum at 350 ° C. The sample is then exposed to SF6 for 1 hour while maintaining the temperature at 20 ° C. The vapor pressure of SF6 is maintained at the pressure provided by liquid SF6 at 400 Torr. The sample is weighed again to determine the amount of SF6 adsorbed. To facilitate these steps, samples may be suspended on the balance during these steps.

In any material production procedure, including techniques such as steaming and heating, it is possible for each particle to be treated to a different degree. For example, particles below the dummy moving along the belt may not be affected by the same atmosphere or temperature as the particles covering the top of the dummy. These factors should be considered in the manufacturing process and in the analysis and testing of the final product. Therefore, it is recommended that any test measurements made on the catalyst be made on each of a number of randomly obtained pellets in order to avoid being mistaken by measurements made simultaneously on several particles. For example, the results of adsorption capacity measurements made using several pellets are indicative of the average adsorption values of all the pellets, and do not indicate whether each particle meets the adsorption criteria. The average adsorption value is within the specification, but each particle is not within the specification.

Example 1

Beta zeolite was obtained from a commercially available source and calcined in air at a temperature of 650 ° C. for 2 hours to remove the template. After calcination, the silica: alumina mole ratio of beta zeolite was 24.2: 1 and the SF6 adsorption capacity found in the analytical test of beta zeolite was 29.3%. Catalyst A was prepared by mixing 0.5 parts by weight of beta zeolite, 48 parts by weight of silica-alumina and 51.5% by weight of alumina in a mill to form a powder mixture. Parts by weight were measured on the basis of exclusion of volatiles. Silica-alumina had a weight ratio of silica: alumina of 78:22. An amount of nitric acid and water, 4% of the powder mixture on a volatile exclusion basis, was added to the powder mixture to form an extruded dough. The dough was extruded to form a 1.6 mm extrudate, which was calcined at 566 ° C. The calcined extrudate was impregnated by an initial impregnation method using a solution containing NiNO 3 and ammonium metatungstate. The wet extrudate was dried and calcined at 510 ° C. using a belt calciner to form catalyst A. Catalyst A included 5.4% Ni and 17.8% W.

Example 2

Catalyst B was prepared according to the same procedure as used for preparing Catalyst A, except that 1 part by weight of beta zeolite, 47.8 parts by weight of silica-alumina and 51.2 parts by weight of alumina were mixed to form a powder mixture.

Example 3

Catalyst C was prepared according to the same procedure as used for preparing Catalyst A, except that 3 parts by weight of beta zeolite, 46.5 parts by weight of silica-alumina and 50.5 parts by weight of alumina were mixed to form a powder mixture.

Example 4 (Comparative Example)

Each of the four batches of the same commercial zeolite beta used as starting material to prepare Catalyst A was calcined to remove the template in the manner described in Example 1. Each batch was hydrothermally treated for 110 minutes. One batch was treated at a temperature of 725 ° C. (1337 ° F.), one batch was treated at a temperature of 880 ° C., and each two batches were treated at a temperature of 920 ° C. The SF6 adsorption capacity of each batch of beta zeolite was measured and the results are shown in Table 1.

Hydrothermal treatment temperature (℃) SF ₆ adsorption capacity (% by weight) 725 26.8 880 17.1 920 12.7 and 13.3

Example 5 (Comparative Example)

Five catalysts, Catalysts D through H, were prepared using the same commercially available beta zeolites used in the preparation of Catalyst A as starting materials. Beta zeolite for each of catalysts D through H was calcined to remove the template in the manner described in Example 1. During the preparation of some of the catalysts D through H, the beta zeolite was hydrothermally treated at a temperature of 880 ° C. for 110 minutes. During the preparation of the remaining catalysts D to H, the beta zeolite was hydrothermally treated at a temperature of 920 ° C. The amount of beta zeolite for each of the catalysts D-H ranged from 5 to 20% by weight, based on the total amount of the beta zeolite and the carrier, on the basis of excluding volatiles. For each catalyst D to H, the SF6 adsorption capacity of the beta zeolite used for each catalyst was 12.7-17.1 wt% after hydrothermal treatment.

Example 6

Relative performance of Catalysts A through H was determined by pilot plant scale testing using reduced pressure diesel (VGO) with an API specific gravity of 22.48 and a final boiling point temperature of 557 ° C. by simulated distillation. VGO contained 2.24 wt% sulfur and 730 wt ppm nitrogen. The catalyst was presulfurized and the high space velocity ripening procedure normally performed before the test was applied to ensure that the test operation did not include starting artifacts. During each test, the temperature of the reaction zone was controlled to convert to a liquid product collected at 1.0 hr ⁻¹ LHSV. The reaction section was operated at a pressure of 14,479 kPa (g) (2100 psi (g)) and hydrogen was circulated at a rate of 1684 nl / l (10,000 SCFB). The conversion rate during the test time varied from 50 to 80% by volume. Conversion was defined as the yield of hydrocarbons boiling below 371 ° C. resulting from decomposition of the feed boiling above 371 ° C.

The figure shows a chart of the 149-371 ° C. fractional distillate yield benefits of Catalysts A-H compared to the reference catalyst plotted against the activity benefits compared to the reference catalyst, the activity benefits being required to achieve a 70% conversion of VGO. It is expressed as the reactor temperature. The lower the delta reactor temperature conditions, the higher the catalytic activity. Test results for catalysts A, B and C are indicated by triangles in the figures. Test results for catalysts D through H are shown in the figure with rhombuses, and the smooth curve is drawn along the rhombus.

Catalyst A showed a yield of 2% by weight higher than the curve for Catalysts D to H at the desired delta temperature. Some curve extrapolation is required for Catalysts D through H, but Catalyst A appears to be more active than the curves for Catalysts D through H at a given delta yield. Catalyst B was found to have a 2.5 wt% yield higher than the curves for catalysts D to H at a given delta temperature and 5 ° C. higher activity than the curves for catalysts D to H at a given delta yield. A little extrapolation should be made for the catalysts D to H curves again, but catalyst C has a higher yield than the curves for catalysts D to H at a given delta temperature and is more active than the curves for catalysts D to H at a given delta yield. Found to be higher.

Claims (10)

Contacting a feed stream comprising a hydrocarbon having a boiling point between 340 ° C. and 565 ° C. with a catalyst comprising a hydrogenation component and a beta zeolite, wherein the hydrogenation component is in the group consisting of nickel, cobalt, tungsten, molybdenum and any combination thereof Wherein the beta zeolite comprises a selected metal component, wherein the beta zeolite has a silica: alumina mole ratio of less than 30: 1 and an SF ₆ adsorption capacity of at least 28% by weight. The hydrocracking according to claim 1, wherein the catalyst comprises a support, and the catalyst contains hydrocracking containing less than 3% by weight of a positive amount of beta zeolite based on the total amount of beta zeolite and the support on a volatile exclusion basis. Way. The hydrocracking method according to claim 1 or 2, wherein the silica: alumina molar ratio is from 9: 1 to less than 25: 1. The support according to any one of claims 1 to 3, wherein the support comprises a refractory inorganic oxide selected from the group consisting of alumina, silica-alumina, silica, zirconia, titania, boria and zirconia-alumina, and any combination thereof. Hydrocracking method comprising. 5. The hydrocracking process according to claim 1, wherein the catalyst is sulfided prior to contact with the feed stream. 6. The hydrocracking process according to any one of claims 1 to 5 wherein the feed stream comprises at least 0.01% by weight of nitrogen. The hydrocracking process according to any one of claims 1 to 6, wherein the beta zeolite is not subjected to steam treatment to increase the selectivity for the production of middle distillate products prior to contacting the feed stream. 8. The beta zeolite of claim 1, wherein the beta zeolite has a temperature of up to 650 ° C. prior to contact with the feed stream, a substantial amount of vapor up to 10 mol% based on the weight of the vapor in contact with the zeolite beta, and A hydrocracking method which is treated by steam treatment under hydrothermal conditions including a substantial amount of time of 2 hours or less. The hydrocracking method of claim 1, wherein the catalyst comprises a hydrogenation component selected from the group consisting of nickel, cobalt, tungsten, molybdenum and any combination thereof. The hydrocracking method according to any one of claims 1 to 9, comprising a first step comprising the catalyst and a second step comprising the catalyst.

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