Nickel-Containing Hydrocracking Catalyst and Process

The invention is further illustrated by the following examples which are illustrative of specific modes of practicing the invention and are not intended as limiting the scope of the invention defined by the appended claims.

A blend of hydrotreated and partially hydrocracked gas oil having the chemical and physical properties shown in the following Table II:

The compositions of the catalysts tested in accordance with the foregoing procedure are specified in Table III. As shown, each of the catalysts (conventional catalysts R, F, and D and catalysts of the invention A, B, C and E) contains nickel or nickel plus molybdenum active components, and the supports of the catalysts contain the same proportion of one of two stabilized zeolites, one being LZ-210, a proprietary zeolite of Union Carbide, and the second, a stabilized Y zeolite, Y-82, prepared in accordance with the method of U.S. Pat. No. 3,929,672 herein incorporated by reference in its entirety. The two zeolites may be distinguished from each other at least by their silica-to-alumina ratios. The stabilized Y zeolite, Y-82, is hydrophillic and has a silica-to-alumina mole ratio about 5.8 The LZ-210 zeolites have a silica-to-alumina mole ratio higher than that of Y-82, that is, about 6.5 and 9.0.

In addition to containing one of the two specified zeolites, the catalysts set forth in Table III are further composed of an alumina binder material.

Each of the foregoing catalysts is prepared by comulling the zeolites with an alumina hydrogel. The comulled paste is extruded in particulate form having a cross-sectional cylindrical shape. The particulates, of a length between about 1/4 and 1/2 inch, are dried and calcined in air. The particulates are then impregnated with an aqueous solution of nickel nitrate in an amount sufficient to produce final Catalysts A, C, D and E having the weight percent set forth in Table III. In preparing Catalysts R and B, an aqueous solution containing ammonium heptamolybdate and nickel nitrate is used to impregnate the particulates. Conventional Catalyst F is prepared by impregnating the particles with an aqueous solution containing nickel nitrate and ammonium metatungstate. All the impregnated particulates are dried, calcined and sulfided in an identical manner.

The data in Table III show that Catalysts A and B of the invention (containing Y-82 zeolite) exhibit octane boosting properties as compared to conventional Catalysts R and D. Also, Catalyst B, having a NiO/MoO.sub.3 mole ratio greater than 2 to 1, demonstrates an activity advantage over Catalyst A and, under ammonia-rich conditions, demonstrates octane boosting properties over Catalyst R and about equivalent to Catalyst R under ammonia-deficient conditions. Furthermore Catalysts C and E of the invention (containing LZ-210 zeolite) exhibit octane boosting properties as compared to conventional Catalyst F.

The data obtained from the runs indicate that a catalyst containing a zeolite Y-82 support and a hydrogenation metal consisting essentially of a nickel component (such as Catalyst A) exhibits a superiority over Catalyst R in increasing the octane numbers of both light and heavy gasoline products obtained from the feedstock under both ammonia-rich and ammonia-deficient conditions. For instance, the octane numbers of the light gasoline fraction are from 3.7 to 5.1 numbers higher in run no. 9 (Catalyst A) than run no. 8 (conventional Catalyst R containing 5 NiO, 15 MoO.sub.3 supported on Y-82 zeolite) under ammonia-rich conditions. Also, the octane numbers of the heavy gasoline fraction are about 4.8 numbers higher in run no. 9 vs. run no. 8. Such boosts in the octane rating in run no. 9 vs. run no 8 are observed while the activity of Catalyst A is 3.degree. F. less under ammonia-rich conditions. Under the ammonia-deficient conditions of run nos. 1 and 2, Catalyst A exhibits an octane increase from 1.3 to 1.5 numbers for light gasolines and from 1.6 to 2.3 for heavy gasolines compared to Catalyst R.

Furthermore, when LZ-210 is used in Catalyst C of the invention, the octane numbers are also improved significantly in run no. 12 vs. run no. 14, i.e., from 2.6 to 4.0 numbers higher than conventional Catalyst F (containing nick.TM.el and tungsten on LZ-210) for light gasoline fractions and 1.6 to 7.8 numbers higher for heavy gasoline fractions under ammonia-rich conditions. Moreover, when the silica-to-alumina ratio of LZ-210 is decreased from 9.0 (in Catalyst C) to 6.5 (in Catalyst E), the octane number improvement for heavy gasoline fractions by Catalyst E vs. Catalyst F (run no. 13 vs. run no. 14) is even greater than Catalyst C vs. Catalyst F under ammonia-rich conditions of run no. 13 vs. run no. 12. Under ammonia-deficient conditions (run no. 6 vs. run nos. 5 or 7), Catalyst E also provides a substantial improvement of 7.3 to 9.6 research octane numbers and 5.6 to 6.8 motor octane numbers for heavy gasoline fractions over Catalyst C or F and is more active by 29.degree. F. and 11.degree. F. respectively.

When the catalyst contains a cracking component and one or more hydrogenation components consisting essentially of more than 13 weight percent of nickel, calculated as NiO, the octane numbers of the light gasoline fraction are consistently higher than those for a catalyst containing the same cracking component and a hydrogenation component consisting essentially of lesser amounts of nickel. The comparison of run no. 2 vs. run no. 4 and the comparison of run no. 9 vs. run no. 11 demonstrate such results in both ammonia-rich and ammonia-deficient conditions. Catalyst A (containing Y-82 zeolite and consisting essentially of 15 weight percent of nickel, as NiO) exhibits an improvement over Catalyst D (containing Y-82 zeolite and consisting essentially of 5 weight percent of nickel, as NiO) of 2.3 to 3.0 numbers (run no. 2 vs. run no. 4) and 1.5 to 2.3 numbers (run no. 9 vs. run no. 11) for light gasoline fractions. It is clear from the data that a catalyst containing relatively large amounts of nickel components, i.e., greater than 13 weight percent, and preferably greater than about 14 weight percent, calculated as NiO, provides an unusual improvement in gasoline octane quality as compared to the same catalyst containing less than 13 weight percent of nickel, as NiO.

The data from the runs also indicate that a NiO/MoO.sub.3 mole ratio greater than 2 to 1 in the catalyst of the invention provides improved octane numbers for both light and heavy gasoline fractions. Under ammonia-rich conditions, the octane numbers of the light and heavy gasoline fractions obtained from run no. 10 (using Catalyst B having 15 NiO and 3 MoO.sub.3, i.e., NiO/MoO.sub.3 mole ratio of 9.6 to 1) are typically higher than those obtained from run no. 8 (using Catalyst R having 5 NiO and 15 MoO.sub.3, Ni/MoO.sub.3 mole ratio of 0.64 to 1), i.e., an improvement up to 1.2 numbers for light gasoline fractions and up to 3.5 numbers for heavy gasoline fractions (run. no. 10 vs. run no. 8). Furthermore in the comparison of Catalyst B vs. Catalyst A (containing no molybdenum), the data further show that the octane numbers of the light and heavy gasoline fractions obtained from obtained from run no. 10 (Catalyst B) and the activity nearly equivalent, i.e., under ammonia-rich conditions an improvement of 3.3 to 3.9 numbers for light gasoline fractions and 1.3 to 2.3 numbers for heavy gasoline fractions (run no. 9 vs. run no. 10). Also, Catalyst A is only 2.degree. F. less active than Catalyst B. On the other hand, under ammonia-deficient conditions, Catalyst A exhibits an improvement of 1.3 to 2.9 numbers for light gasoline fractions and 0.7 to 4.4 numbers for heavy gasoline fractions vs. Catalyst B (see run no. 3 vs. run no. 2); however, Catalyst A is about 16.degree. F. less active than Catalyst B under such ammonia-deficient conditions. The data obtained from the experiment indicate that Catalyst B of the invention (having a NiO/MoO.sub.3 mole ratio of 9.6 to 1) is useful for boosting octane and has an activity advantage over the catalysts containing no molybdenum; however, under suitable conditions, Catalyst A of the invention can outperform Catalyst B in increasing octane values in the gasoline product.

Another blend of hydrotreated and partially hydrocracked gas oil having the chemical and physical properties shown in Table IV:

is passed in ten runs (runs 15 through 24) in the same manner as disclosed in Example I. Runs 15 through 19 are operated in the same manner as runs 1 through 7 in Example I, with runs 20 through 24 operated in the same manner as runs 8 through 14 in Example I.

The compositions of the catalysts tested are specified in Table V. Catalysts R and A are prepared in the same manner as in Example I and contain the same nominal compositions. Catalyst G is prepared in the same manner as Catalyst B in Example I, except a smaller portion of ammonium heptamolybdate is mixed with the other materials and the final nominal composition of Catalyst B contains 1.0 weight percent of molybdenum calculated as MoO.sub.3. Catalysts L and FA are prepared in the same manner as respective Catalysts C and F in Example I, except the LZ-210 has a silica-to-alumina ratio of 12.

The data in Table V show that Catalysts A and G of the invention exhibit octane boosting properties compared to conventional Catalyst R Also, Catalyst G, having a NiO/MoO.sub.3 mole ratio of the metals greater than 2 to 1, demonstrates an activity advantage over Catalyst A and, under both ammonia-rich and ammonia-deficient conditions, demonstrates octane boosting properties over Catalyst R. Furthermore, Catalyst L of the invention exhibits octane boosting properties as compared to conventional Catalyst FA.

The data obtained from the runs in Table V indicate that Catalyst A (containing nickel and no molybdenum) continues to maintain its superiority over conventional Catalyst R for increasing the octane numbers of light gasoline products obtained from a similar feedstock to that in Example I. For instance, in comparing run nos. 16 and 21 (Catalyst A) to run nos. 15 and 20 (Catalyst R), respectively, the octane numbers of the light gasoline fraction are greater by up to 2.8 numbers for Catalyst A than for Catalyst R and for the heavy gasoline fraction are greater by up to 4.9 numbers. However, the activity of Catalyst A relative to Catalyst R declines by 35.degree. F. in run no. 16 vs. run no. 15 and by 11.degree. F. in run no. 21 vs. run no. 20.

Catalyst G (containing nickel and only 1.0 weight percent of molybdenum, i.e. NiO/Mo03 mole ratio of 28.9) also exhibits a superiority over Catalyst R in increasing the octane numbers of both light and heavy gasoline fractions For instance, the octane numbers of the light gasoline fraction are up to 2.0 and 3.1 numbers higher in run nos. 17 and 22 (vs. run nos. 15 and 20, respectively) and the octane numbers of the heavy gasoline fraction are up to 4.6 and 5.4 numbers higher.

The data in Table V also indicate that Catalyst G exhibits a superiority in activity and at least maintains, or in some cases improves, the octane numbers of gasoline products obtained from the feedstock as compared to a catalyst (Catalyst A) containing a cracking component and a hydrogenation component consisting essentially of nickel components. For instance, the octane numbers of the light gasoline fraction are from 0.5 to 0.6 numbers higher in run no. 17 (Catalyst G) than run no. 16 (Catalyst A) and 0.3 to 0.8 higher in run no. 22 than run no. 21.

Catalyst G also exhibits a substantial activity advantage compared to Catalyst A. The activity for Catalyst G in run no. 17 is only 15.degree. F. less than Catalyst R whereas Catalyst A exhibits a 35.degree. F. decline in run no. 16. However, unlike the runs in Example I, this time the nickel-only catalyst (Catalyst A) and the nickel-molybdenum catalyst (Catalyst G) are about equal for boosting octane. Furthermore, under ammonia-rich conditions, Catalyst G exhibits an activity advantage of 5.degree. F. (compared to Catalyst A) in the comparison of run no. 22 vs. run no. 21. Thus, the data obtained from the experiment indicate that, although Catalyst A of the invention is useful for improving octane, Catalyst G of the invention is useful for improving octane and is also far more active for converting gas oil feedstocks to gasoline.

Both Catalyst L and conventional Catalyst FA contain supports having an LZ-210 zeolite with a silica-to-alumina ratio of 12.0. Catalyst L (containing nickel) provides a consistent boost in both research and motor octane numbers compared to conventional Catalyst FA (containing nickel and tungsten). The comparison of run no. 18 vs. run no. 19 under ammonia-deficient conditions and run no. 23 vs. run no. 24 under ammonia-rich conditions illustrates that Catalyst L improves the octane quality of the products from 1.6 to 3.1 numbers under ammonia-deficient conditions and from 2.2 to 6.9 numbers under ammonia-rich conditions.

Thus, the data for the experiment indicate that Catalysts A and L of the invention have superior octane boosting properties (compared to respective Catalysts R and FA) provided by the presence on the catalysts of only nickel components (at least 13 weight percent, NiO) in combination with Y-82 and LZ-210 cracking components, respectively. Furthermore, the data indicate that the nickel-molybdenum Catalyst G, is more active than the nickel-only version (Catalyst A) and still exhibits octane boosting properties compared to a conventional nickel-molybdenum catalyst (Catalyst R).

In view of the foregoing description of the invention including the examples thereof, it is evident that many alternatives, modifications, and variations can be made by those skilled in the art without departing from the concept of the present invention. For instance, the catalyst may be employed in other hydrocarbon conversion processes, such as for hydrodewaxing or isomerizing a feedstock containing hydrocarbon compounds. Accordingly, it is intended in the invention to embrace all such alternatives, modifications, and variations as may fall within the scope of the appended claims.