Patent Publication Number: US-3876524-A

Title: Production of jet fuel by a hydrocarbon conversion process using a catalyst comprising palladium and an amorphous aluminosilicate component

Description:
Ciapetta et a1. 208/1 10 United States Patent 1 1 1111 3,876,524  
 White et al. Apr. 8, 1975 1 PRODUCTION OF JET FUEL BY A 2.945.806 7/1960 Ciapetta 208/110 HYDROCARBON CONVERSION PROCESS 3.169.107 2/1965 Coonradt et al.... 208/111 3.243.368 3/1966 Mulaskey 208/111 5211 18 333 5;f figgggg 3.453.204 7/1969 Mulaskey 208/111 ALUMINOSILICATE COMPONENT Primary Examiner-Delbert E. Gantz [75] lnvemors&#39; g gz &#39;ggy g fi gmg gz gt. Assistant E.\&#39;aminerG. E. Schmitkons g Altar/1e Agent, or Firm-G. F Magdeburger; R. H. [73] Assignee: Chevron Research Company, San Davies Francisco. Calif.  
 [22] Filed: June 25, 1973 57 ABSTRACT [21] Appl. No.: 373,592 l 1 Rehted Application Data A hydrocarbon hydroconversion process, especially a [63] Continuation-impart of Ser No 129 986 March 31 hydrocracking proqess for the Producti? of jet .fuel 97] PM No 3 769 235 using a hydrocrackmg catalyst comprising palladmm and an amorphous aluminosilicate component having 52 us. Cl 208/111- 252/416&#39; 252/455 R an alumina of 40 95 weight Percent said [51] Int Cl. C1bg13/02 ,B01j H/ catalyst, with the hydrogenating component in the [58] Field h 208/1 1 l oxide form, having been subjected to a heat treatment in a substantially dry nonreducing gas at a tempera- [56] References Cited ture in the range 1,200 to 1,800F.  
 7 94 gm STATES PATENTS 5 Claims, No Drawings PRODUCTION OF JET FUEL BY A HYDROCARBON CONVERSION PROCESS USING A CATALYST COMPRISING PALLADIUM AND AN AMORPHOUS ALUMINOSILICATE COMPONENT CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of US. application Ser. No. -l29,986, filed Mar. 31, 1971, now US. Pat. No. 3,769,235.  
 INTRODUCTION The present invention relates to an improved hydrocarbon conversion catalyst, and to an improved hydrocarbon conversion process using said catalyst. More particularly, the present invention covers a catalyst comprising palladium and an amorphous aluminosilicate component, and to an improved hydrocarbon conversion process using said catalyst. In one embodiment, the present invention is directed to a hydrocracking catalyst comprising palladium and an amorphous aluminosilicate component. The catalyst of the present invention is useful in various hydrocarbon conversion processes, including hydrogenation, dehydrogenation, alkylation and reforming processes; however, its preferred application is as a catalyst in a hydrocracking process, particularly a hydrocracking process being op erated with jet fuel production as a primary objective. It is known that hydrocracking processes using catalysts comprising noble metal components associated with amorphous aluminosilicate components have been used to produce jet fuel. However, there has been a strong continuing need for improvement not only of the jet fuel yield in such processes, but also of the total C liquid yield, with concomitant minimization of the production of Cr light hydrocarbon gases. There also has been a continuing need in such processes for improvements directed to increasing catalyst activity, which is needed to reduce catalyst operating temperatures and aid in prolonging catalyst life.  
 STATEMENT OF INVENTION In accordance with the present invention, there is provided a hydrocarbon conversion catalyst, preferably intended for use as a hydrocracking catalyst, comprising palladium in the metal, oxide or sulfide form, or mixtures thereof, and an amorphous aluminosilicate component having an alumina content of 40 to 95 weight percent, preferably above 50 weight percent, more preferably between 50 and 95 weight percent, with good results being obtainable with alumina contents between 50 and 85 weight percent, said catalyst having an activity as induced therein by having been subjected, with the hydrogenating component in the oxide form, to a heat treatment in a substantially dry non-reducing gas, for example air, at a temperature in the range l,200 to l,800F. Said gas will be considered substantially dry if it contains less than 1 weight percent water. Preferably it will contain less than 0.1 weight percent water, and more preferably less than 0.01 weight percent water.  
  It is desirable that the catalysts of the present invention have a surface area of at least 100 square meters per gram and a bulk density such that the product of the numerical values of surface area and bulk density is in the range of 100 to 450, preferably 200 to 300 square meters/millilitre.  
  Further in accordance with the present invention, there is provided hydrocarbon conversion processes using the above-described catalyst, particularly a hydrocracking process which comprises hydrocracking a hydrocarbon feedstock in a reaction zone at conventional hydrocracking conditions in the presence of hydrogen and a catalyst comprising palladium and an amorphous aluminosilicate component having an alumina content of 40 to 95 weight percent, the numerical product of the surface area and bulk density of said catalyst preferably being in the range of 100 to 450, and recovering from said reaction zone a 300-550F. jet fuel product in a yield greater than 50 volume percent, based on said feedstock, with an accompanying production of C light gases of less than 8 volume percent, based on said feedstock. Further, said catalyst used in said process is a catalyst which has been subjected, with the hydrogenating component in the oxide form, to a heat treatment in a substantially dry nonreducing gas, for example air, at a temperature in the range of 1,200 to l,800F. Said heat treatment conveniently is accom&#39; plished in a flowing stream of heated air.  
 CATALYST CONSTITUENTS AND PROPORTIONS THEREOF The hydrocarbon conversion catalyst of the present invention contains an amorphous aluminosilicate component having an alumina content of 40 to 95 weight percent, preferably 50 to weight percent. That is, the alumina/silica weight ratio is 40/60 to /5, preferably 50/50 to 80/20. Said aluminosilicate component can be prepared by conventional methods, for example by cogelation.  
  The hydrogenating component of the subject invention is palladium. The hydrogenating component will be present in the catalyst in an amount of 0.1 to 10 weight percent, preferably 0.1 to 1 weight percent, and more preferably 0.2 to 0.6 weight percent, calculated as metal.  
  The heat treatment at l,200 to l,800F. is accomplished with the hydrogenating component of the catalyst in the oxide form, with a substantially dry nonreducing gas under nonreducing conditions. During hydrocracking process use the hydrogenating component will tend to become reduced under the conditions prevailing in the hydrocracking reaction zone.  
 CATALYST PHYSICAL CHARACTERISTICS The catalyst of the present invention will have a surface area of at least square meters per gram, and a bulk density such that the numerical product of the surface area and the bulk density is in the range of 100 to 450, preferably 200 to 300.  
 CATALYST PREPARATION The amorphous aluminosilicate component of the catalyst of the present invention may be prepared by any conventional method, for example cogelation. The aluminosilicate component after formation thereof may be dried and subjected to a heat treatment, for example at 800F., prior to impregnation of the aluminosilicate component with a precursor of the hydrogenating component. The hydrogenating component may also be added to the cogel before drying.  
  Following preparation of the aluminosilicate component, that component may be impregnated with any suitable precursor of the hydrogenating component,  
 and the resulting composite may be dried, all in a conventional manner. Prior to use in a hydrocarbon conversion process, however, the catalyst composite so prepared is subjected, with the hydrogenating component thereof in the oxide form, to a heat treatment in a substantially dry nonreducing gas at a temperature in the range 1,200 to 1,800F., preferably l,450 to I,7OOF., for a period which may range from 0.25 to 48 hours, preferably 0.5 to 10 hours, and more preferably 1 to 5 hours. Particularly good results have been obtained with heat treatments of l to 4 hours at 1,600F. The necessary oxide form of the hydrogenating component may be attained during said heat treatment, as the result of the presence of oxygen in said nonreducing gas, or may be the result of a previous heat treatment step such as calcination in air at a temperature of at least 450F.  
  Said heat treatment in a substantially dry nonreducing gas preferably is carried out in a stream of substantially dry air at the indicated temperature.  
 HYDROCARBON FEEDSTOCKS The catalyst of the present invention is effective in converting a wide range of hydrocarbon feedstocks, including petroleum distillates, petroleum residua, and various cycle stocks. Preferably the hydrocarbon feedstocks will boil in a range of 400 to 950F., preferably 500 to 950F.  
  The nitrogen content of the hydrocarbon feedstocks should be below 0.05 wt. preferably below 0.02 wt. and more preferably below ppm. The sulfur content of the feedstocks also should be below 0.05 wt. /z, preferably below 0.02 wt. and more preferably below 10 ppm. If desired, the hydrocarbon feedstocks may be subjected to a conventional hydrofining pretreatment step prior to being converted in the presence of the catalyst of the present invention.  
 HYDROCARBON CONVERSION PROCESSES AND REACTION CONDITIONS The catalyst of the present invention is useful in many hydrocarbon conversion processes, including hydrogenation, dehydrogenation, alkylation and reforming processes, but it is especially useful when used in a hydrocracking process. Conventional hydroconversion process conditions are used depending on the particular hydroconversion process being carried out.  
  Hydrocracking process conditions may be conventional conditions, for example a temperature in the range 450 to 850F., a pressure in the range 500 to 3,500 psig or higher, a space velocity in the range 0.5 to 3.0, and a total hydrogen rate of 1,000 to 20,000 SCF, preferably 1000 to 5000 SCF, of hydrogen per barrel of feedstock.  
  When the catalyst is contacted with the hydrogen used in a hydrocracking reaction, some reduction to metal of any hydrogenating component oxides that are present will take place. This is not detrimental, so long as the hydrogen does not contact the catalyst at a temperature appreciably higher than reaction temperature at the start of the run.  
 EXAMPLES Example 1 Fourteen-hundred grams of AlCl .6H. ,O were dissolved in 5 litres of H 0 to form a first solution. Threehundred grams of sodium silicate were dissolved in 4 litres of water to form a second solution. Said first and second solutions were combined to form a mixture, the pH of which was adjusted to 7 by the addition of 3 litres ofa solution of2 parts H 0 and 1 part NH,OH. The resulting mixture, in the form of a suspension, was heated to 150F., the pH was readjusted to 7, and the mixture was filtered to produce a cogel paste filter cake. The filter cake was washed 4 times in 13 litres of 1% ammonium acetate solution at 150F., and once in 13 litres of H 0 at 150F. The resulting alumina-silica cogel paste had the following characteristics:  
 Weight in grams 5905 Total solids content, wt. 6.75 Pore volume of solids, ml/gm, 0.8 Al O;,/SiO. weight ratio 72/28 To 2,660 grams of the aforesaid alumina-silica paste were added 4.61 grams of palladium tetra ammino dinitrate dissolved in 83 ml. of H 0. The resulting mixture was blended in a kitchen mixer, together with an additional 450 ml. of H 0, for several hours. The resulting product was dried, broken into pieces, and calcined in substantially dry air for 4 hours at 450F., 8 hours at 1,000F. and about 4 hours at 1,600F. The resulting catalyst was ground up, producing approximately 93 grams in a l0l6 mesh size range, and approximately 93 grams in a size range below 16 mesh. The 10-16 mesh size material, having a surface area of 300 m&#39; /g., was again calcined in substantially dry air for 1 hour at 1600F. The resulting catalyst had the following characteristics:  
 Pore volume, cc/g. 0.546 Bulk density, g/ml. 0.61 Palladium content, wt. 71 0.84 Average pore diameter, Angstroms 73 Example 2 Eleven-hundred and thirty grams of AlCl .6H O were dissolved in 5 litres of H 0, and ml. glacial acetic acid was added, to form a first solution. Five-hundred and forty grams of sodium silicate were dissolved in 2.5 litres of water to form a second solution. Said first and second solutions were combined to form a mixture, the pH of which was adjusted to 7 by the addition of 3 litres of a solution of 2 parts H 0 and 1 part NH,OH. The resulting mixture, in the form ofa suspension, was heated to F., the pH was readjusted to 7, and the mixture was filtered to produce a cogel paste filter cake having a solids content of 8.06 wt. The filter cake was washed 4 times in 14 litres of 1% ammonium acetate at 150F., once in 14 litres of H 0 at 150F., and was oven dried overnight at about 250F. The resulting dried material had these characteristics:  
 Total solids content. wt. 7: 71.3 Pore volume of solids, cc/g. 0.195 Al O -./SiO- weight ratio 60/40 To 484 grams of the aforesaid dried alumina-silica material were added 8.869 grams of palladium tetra ammino dinitrate dissolved in 95 ml H O. The resulting mixture was mixed until evenly wetted and then was dried in an oven over-night at 250F. The dried mixture was separated into three catalyst portions: (1) about 200 cc. in 10-24 mesh size; (2) 84 cc. in 24-60 mesh size; and (3) all remaining material (about 220 cc.) of smaller than 24 mesh. These three catalyst portions were calcined in substantially dry air as follows:  
 Catalyst portion (2) was analyzed and found to have the following additional characteristics:  
 Surface area. m /g. 266 Palladium content. wt. 7! 0.88 Particle density. g./cc. I.6l Pore volume. ccJg. 0.23 Average pore diameter. Angstroms 35 Silica content. wt. &#34;/1 4] Nominal alumina/silica weight ratio 60/40 Catalyst portions (1) and (3) had similar characteristics.  
 Example 3 ASTM D-l I60 Boiling Range. F.  
 Start 553 571 589 l()/( 595 307: 6 l 7 50 646 70% 684 9071 732 95% 763 End 859 Other C haractcristics Gravity. API 39.9 Aniline point. F. l92.7 Sulfur. ppm I-2 Nitrogen. ppm 0.l Pour point. .F. +55 Paraffins plus naphthenes. vol. 7: 90  
 Aromatics. vol. &#39;7: H)  
 The above-described feedstock was hydrocracked in a recycle run under these conditions:  
 Total pressure. psig I200 Liquid hourly space vclocity. V/V/hr. I.50 Conversion. liquid vol. /1 to 550F.- 60 Recycle gas rate. SCF/bbl. of feed 5600 Boiling range of liquid product recycled Hydrogen consumption; SCF/bbl. of feed The results of said recycle run were as follows:  
 Starting temperature. F. 6l7 Yield of C liquid product. vol. 7! 8 Yield of 300550F. jet fuel. vol. 7!  
 Example 4 Catalyst portion (1 of Example 2 was used to hydrocrack another portion of the same feedstock used in Example 3. The feedstock was hydrocracked in a recycle run under these conditions:  
 Total pressure. psig I200 Liquid hourly space velocity. V/V/hr. 1.5 Conversion. liquid vol. &#39;7: to 550F. 60 Recycle gas rate. SCF/bbl. of feed 5600 Boiling range of liquid product recycled 550F Hydrogen consumption. SCF/bbl. of feed I000 The results of said recycle run were as follows:  
 Starting temperature. F. 565 Yield of C;. liquid product, vol. 7: I07 Yield of 300550F. jet fuel, vol. Q 63 Fouling rate at end of 300 hours operation. F./hr. 0.02  
 Example 5 This is an example of a run using a lower palladium content catalyst prepared by impregnation of a cogel before calcining.  
  Five-hundred grams of a cogel was prepared by cogelation at a pH of 6.5 (similar to Example 2), drying at F. to a solids content of 30%, washing with ammonium acetate (similar to Example 2). The washed cogel was contacted with a solution containing 0.83 grams palladium tetra ammino dinitrate in 714 ml. of H 0 for 50 minutes. The solution was removed and the cogel was dried for 4 hours at F. The cogel, in 10-16 mesh form, was dried and calcined in substantially dry air for 4 hours at 450F., 8 hours at 1.000F. and 4 hours at 1,600F.  
 The catalyst had the following characteristics:  
  This catalyst was used to hydrocrack another portion of the feedstock used in Example 3. The feedstock was hydro-cracked in a recycle run under these conditions:  
 Total pressure. psig I200 Liquid hourly space velocity. V/V/hr. 3  
 Conversion. liquid volume &#39;71 to 550F.- 60 Recycle gas rate. SCF/bbl. of feed 5600 Boiling range of liquid product recycled 550F. Hydrogen consumption. SCF/bbl. of feed 1000 The results of said recycle run were as follows:  
 Starting temperature. F. 603 Yield of C liquid product. vol. &#34;/1 I07 Yield of 300-550F. jet fuel. vol. 62  
 Fouling rate at 300 hours. F./hr. 0.05  
 Examples 6 and 7 The following examples of two catalysts that were prepared and tested show the beneficial effect of cal cining in substantially dry air at a temperature higher than l,200F.  
 ite, with the hydrogenating component in the oxide form, has been subjected to a heat treatment in a sub- Effect of Temperature of Heat Treatment in Substantially Dry Air on Catalyst Activity and Jet Yield Ex. 6 Ex. 7  
 Alumina/silica ratio 60/40 60/40 Hydrogenation Component l7! Pd 1% Pd C alcination Temperature, F. I600 I000 Starting Temperature. F. 580 620 Conversion to 550F.-, /1 62 62 Calculated ultimate 30055()F. jet yield, wtf/l 67 63 Calculated ultimate C,,- product. wt. &#34;/1 3.6 5.6  
 Examples 8 and 9 The following examples of two catalysts that were prepared and tested show the effect of alumina/silica ratio on catalyst activity, each catalyst having been calcined at the indicated temperature in substantially dry air.  
 Alumina/Silica ratio 72/28 Starting temperature, F. 616 Hydrogenation component 17: Pd C alcination Temperature, F. 1600 Conversion to 550F.-. /1 Calculated ultimate 300550F. jet yield, wtfi? 69.5 Calculated ultimate C product, wt. 71 3.5  
  These examples show that a larger catalyst temperature span during a run can be obtained by using the more active, 60/40 alumina/silica catalyst.  
 Example This example shows the typical low yields from a conventional catalyst having an alumina content below 40%. A noble metal (0.5% palladium) on fluorided silica-alumina catalyst (containing 0.5% chromium), having an alumina/silica ratio of /65, was used to hydrocrack the feedstock described in Example 3. This catalyst had similar activity and stability, but gave a lower jet fuel yield of 54 vol. and the production of C light gases was greater than 10.5 vol.  
 Example l I This example shows the low jet yield from a conventional catalyst having an alumina content of 28.5%. A nickel sulfide-on-silica-alumina catalyst having an alumina/silica ratio of 35/65, was used to hydrocrack the feedstock in Example 3. This catalyst had similar activity and stability, but gave a lower jet fuel yield of 47.5 vol. 7c, and the production of C light gases was greater than 12.5 vol.  
 SUMMARIES, THEORlES AND CONCLUSIONS Although Applicants do not intend to be bound by any theories they may advance for the unexpectedly improved performance of the catalyst of the present invention, such theories will be set forth here as a possible aid in understanding the present invention.  
 In the present invention the entire catalyst compos ponents; however, after such a heat treatment the amorphous aluminosilicate component would be extremely hygroscopic. Therefore, as a practical matter, an aqueous impregnation technique could not be used. A nonaqueous impregnation technique might be feasible; however, it still would be necessary to keep the heat-treated amorphous aluminosilicate component in a very dry atmosphere at all times following the heat treatment step, and the necessity for such a dry atmosphere would complicate the carrying out even of a nonaqueous impregnation technique.  
  It is believed that while the catalyst of the present invention is being subjected to the nonreducing heat treatment at a temperature in the range l,200 to 1,800F., the activity of the catalyst is increased without lowering the ratio of hydrogenation activity to acidity. It is believed that the high ratio of hydrogenation activity to acidity accounts for the production of high jet fuel yields and high C liquid yields in a hydrocracking process.  
  Applicants have found that there is a critical combination of the level of activation temperature, the alumina/silica ratio, the kind of metal contained in the hydrogenating component, the oxidation state of the hydrogenating component during activation, the nonreducing nature of the gas used during activation and the dryness of the gas used during activation. They have found that if the alumina content of the aluminosilicate component of the catalyst is at least weight percent, and preferably at least 50 weight percent, the total catalyst component will be sufficiently resistant to hightemperature deterioration of surface areas that the catalyst can withstand a nonreducing heat treatment at a temperature in the range l,200 to 1,800F. Applicants further have found that when such high-temperature nonreducing heat treatment is used in conjunction with the other elements and factors of the critical combination discussed above, the very surprising, unpredictable and unobvious improved results discussed herein are obtained. It is only with the catalyst of the present invention that it has been possible to obtain such high C liquid yields, such high jet yields, such a low production of C light gases, and reasonable conversions at such low operating temperatures.  
 What is claimed is:  
  1. A hydrocracking process which comprises hydrocracking a hydrocarbon feedstock in a reaction zone at conventional hydrocracking conditions in the presence of hydrogen and a catalyst comprising a hydrogenating component selected from the group consisting of palladium, palladium sulfide, and palladium oxide in an amount of 0.1 to 10.0 weight percent, calculated as metal, and an amorphous aluminosilicate component having an alumina content of 40 to 95 weight percent, said catalyst having an original activity as induced therein by having been subjected, with the hydrogenating component in the oxide form, to a heat treatment in a substantially dry nonreducing gas at a temperature in the range l,200 to l,800F.; and recovering from said reaction zone a 300550F. jet fuel product in a yield greater than 50 volume percent, based on said feedstock, with an accompanying production of C light gases of less than 8 volume percent, based on said feedstock.  
  2. A hydrocracking process as in claim 1 wherein said hydrogenating component is present in an amount of 0.1 to 1.0 weight percent.  
  3. A hydrocracking process as in claim 1 wherein said hydrogenating component is present in an amount of 0.2 to 0.6 weight percent.  
  4. A hydrocarbon conversion process which comprises contacting a hydrocarbon feedstock in a reaction zone at conventional hydrocarbon conversion conditions with a catalyst comprising a hydrogenating component selected from the group consisting of palladium, palladium sulfide, and palladium oxide in an amount of 0.1 to 10.0 weight percent, calculated as metal, and an amorphous aluminosilicate component having an alumina content of 40 to weight percent, said catalyst having an original activity as induced therein by having been subjected, with the hydrogenating component in the oxide form, to a heat treatment in a substantially dry nonreducing gas at a temperature in the range 1,200 to 1,800F.  
  5. The process of claim 4 wherein said hydrogenating component is selected from the group consisting of palladium and palladium oxide.