NZ205280A - Treating inorganic oxide catalysts with ammonium or boron fluoride - Google Patents

Description

New Zealand Paient Spedficaiion for Paient Number £05280 205280 Priority Date(s): Complete Specification Filed: 3^ Class: fef? J ri I J.Qr)-. . &P. l-i.3^1 Q.% 6pjJ3 7^00 y o» A Ab(.iit.

Publication Date: P.O. Journal, No: . £4 JAN 1986 1» AUG 1903 v " NO DRAWINGS NEW ZEALAND PATENTS ACT, 1953 No.: Date: COMPLETE SPECIFICATION TREATMENT OF CATALYSTS ?/We, MOBIL OIL CORPORATION, a. corporation organised under the laws of the State of New York, United States of America, of 150 East 42nd Street, New York, State of-New York, United States of America, hereby declare the invention for which X / we pray that a patent may be granted to J^Sfe/us, and the method by which it is to be performed, to be particularly described in and by the following statement:- (followed by page la) .X-1522 - 1<*- TREATMENT OF CATALYSTS This invention relates to treatment of inorganic oxide catalysts such as alumina or gallia to enhance their catalytic activity.

The inorganic oxide material alumina has been provided with catalytic activity in the past by contacting same with boron fluoride CBF3). The contacting has been followed by hydrolysis and calcination.. Crystalline aluminosi licates such as zeolites X and Y have been en-10 hanced in catalytic activity by treatment with volatile metal ha I i des, as disclosed in US-A-3,354,078 and 3,644,220.

The present invention, however, provides various inorganic oxides, such as alumina and gallia, with signi-15 ficantly higher acid catalytic activity than prior art methods. This makes it possible to supply matrices of much wider range of acidity levels for commercial zeolite catalysts for use in cracking, alkylation and isomeriz-at i on react i ons.

According to the present invention, a process for improving acid activity of certain inorganic oxide materials, such as alumina or gallia, comprises the sequential steps of contacting said material with ammonium fluoride or volatile boron fluoride, contacting the boron 25 fluoride or ammonium fluoride contacted material with an aqueous ammonium exchange solution such as the hydroxide or a salt, e.g. nitrate, and calcining said ammonium exchange solution contacted material. The resulting material exhibits enhanced Bronsted acidity and, therefore, \ 30 improved acid activity toward catalysis of numerous chemical reactions, such as, for example, alkylation, transalkylation, cracking or isomerization of organic, e.g. hydrocarbon, compounds. This enhanced acid activity material is useful as matrix or support for various zeo-35 lite materials in the manufacture of catalyst for acid catalyzed organic compound conversion processes.

The contacting with ammonium fluoride or volatile boron fluoride is effected at a temperature of from about 0°C to about 100°C, preferably from about ambient to about 50°C. The boron or ammonium fluoride contacted material is then contacted with an aqueous ammonium hydroxide or salt solution, e.g. 1N NH^NOj or 1N NH^OH, and there- ' after calcined at a temperature of from about 200°C to about 5 600°C in an inert atmosphere of air, nitrogen, etc. at sub-atmospheric, atmospheric or superatmospheric pressures for from about 1 minute to about 48 hours.

The fluoride reagent contacting step may be accomplished by admixture of volatile boron fluoride or boron 10 fluoride etherate with an inert gas such as nitrogen or helium at temperatures ranging from about 0°C to about 100°C. It may be accomplished by vacuum impregnation of the inorganic oxide material with ammonium fluoride in water. The amount of fluoride reagent which is utilized 15 is not narrowly critical but usually from about 0.2 to about 2 grams of boron fluoride or ammonium fluoride are used per gram of inorganic oxide material.

The aqueous ammonium exchange solution contacting step may be conducted for a period of time of from 20 about 1 hour to about 20 hours at a temperature of from ambient to about 100°C. The actual ammonium exchange material which may be used is not narrowly critical and will normally be an inorganic salt, such as ammonium nitrate, ammonium sulfate, ammonium chloride, etc., or ammon-25 ium hydroxide.

The use of boron fluoride in the presence of siliceous materials is a problem because boron fluoride is easily hydrolyzed and the HF thereby re.leased attacks silica. Therefore, the inorganic oxide to be treated 30 hereby with boron fluoride will not include silica or mixtures involving silica. If the inorganic oxide material does comprise silica, the present method utilizing a reagent of ammonium fluoride would be the desired procedure.

The inorganic oxide material to be acid activity 35 enhanced by the present method may, if desired, be calcined prior to fluoride reagent contact at a temperature of from about 200°C to about 600°C in an atmosphere of air, nitrogen, etc. for between 1 minute and 48 hours.

The activity-enhanced inorganic oxide material prepared by the present method is useful as a catalyst component for acid catalyzed organic compound conversion reactions. Such reactions include, as non-limiting examples, cracking of hydrocarbons, wherein the reaction 5 conditions include a temperature of from about 300°C to about 800°C, a pressure of from about 15 psia to about 500 psia, and a weight hourly space velocity of from about 0.1 to about 20; and conversion of methanol to gasoline wherein the reaction conditions include a temperature of 10 from about 300°C to about 550°C, a pressure of from about 5 psia to about 500 psia, and a weight hourly space velocity of from about 0.1 to about 100.

In practising a particularly desired chemical conversion process, it may be useful to incorporate the 15 above-described activity enhanced inorganic oxide material, especially when used as matrix in a zeolite-containing catalyst composition, with additional matrix comprising another material resistant to the temperature and other conditions employed in the process. Such additional mat-20 rix material is useful as a binder and imparts additional resistance to the catalyst for the severe temperature, pressure and reactant feed stream velocity conditions encountered in many cracking processes. Suitable matrices are described in our EP-A-1695.

The following Examples illustrate the invention.

EXAMPLE 1 A one gram sample of Kaiser gamma-alumina was vacuum impregnated with 0.9 grams of ammonium fluoride (NH4F) in water at a temperature of 25°C. Considerable 30 ammonia was evolved. After 30 minutes contact, the ammonium fluoride contacted material was dried at 130°C, and then treated three times with 1N aqueous ammonium nitrate (NH^NOj) solution. Each ammonium nitrate contact was followed by water washing. The finally washed material 35 was then dried at 130°C and calcined for 30 minutes at 538°C in air.

EXAMPLE 2 A one gram sample of the same alumina as used in Example 1 was saturated with boron fluoride (BF3). The BF3 2 0 5 Z 8 0 addition was carried out at 25°-95°C. The saturation point was determined as the point at which heat of adsorption no Longer evolved. Any further addition of the BF3 at this point would have actually cooled the alumina. At the 5 saturation point the flow of boron fluoride was stopped and 25°C (ambient) air was drawn through the alumina for 30 minutes. The boron fluoride contacted material was then dried at 130°C for 30 minutes to remove the last traces of unreacted or lightly held boron fluoride. The 10 dried material was then treated with 1N aqueous solution of NH4NO3 and calcined as in Example 1.

EXAMPLE 3 A sample of UOP bimodal gamma-alumina beads was treated with BF3 as in Example 2 without NH4NO3 treat-15 ment. The boron fluoride contacted alumina was calcined as above. This was a prior art method for alumina activation conducted for comparison purposes.

EXAMPLE 4 Another sample of the bimodal alumina beads was 20 treated with BF3 as in Example 3, hydrolyzed with de-mineralized water and calcined as above. There was no aqueous ammonium hydroxide or salt treatment. This, again, was a prior art method for alumina activation conducted for comparison purposes.

EXAMPLE 5 Another sample of the bimodal alumina beads was treated as in Example 2.

EXAMPLE 6 The final product inorganic oxide materials from 30 Examples 1 through 5 along with samples of the two aluminas used (untreated) were subjected to the Alpha Test with results listed below: Products of Example Alpha Value gamma-alumina (base 0.2 bimodal alumina beads (base) 0.2 1 (NH^F/NH4NO3/ca Icination) 4.5 2 BF3/NH4NO3/ca Icination) 15 3 (BF3/ca Icination) 2.8

Claims (7)

205280 - 5 - Products of Example Alpha value A-CBFj/K^O/calci nation) 8.7 5 (BFj/NH^NOj/calci nation) 23 It is observed from the above results that the 5 present method is highly useful for enhancing acid catalytic activity of certain inorganic oxide materials. Comparison of the Alpha Values for the products of Examples 1 and 2 with that of untreated gamma-alumina indicates a 2150 to 7400 percent enhancement in activity. Com-10 parison of the Alpha Value for the product of Example 5 with that of untreated bimodal alumina beads indicates a 11,400 percent enhancement in activity. Comparison of the results for Example 5 material with those for the materials of Examples 3 and 4 show the improvement provided 15 by the present method over the prior art techniques. The Alpha Test is descrcibed in U.S. Patent 3,354,078 and in The Journal of Catalysis, Vol. IV, pp. 522-529 (August 1965). 205280 Wi/lAT-fAV;.: CLA.!I-J !3; ~ 6 -

1. A process for enhancing the activity of an inorganic oxide which comprises contacting said material with ammonium fluoride or boron fluoride at a temperature of 0°C to 100°C, contacting said fluoride-contacted material with an aqueous ammonium exchange solution and thereafter calcining said material at a tempera-ture of 200°C to 600°C.

2. The process of claim 1 wherein said inorganic oxide . is alumina or gallia.

3. The process of claim 1 or claim 2 wherein said aqueous ammonium exchange solution comprises ammonium hydroxide or an ammonium salt.

4. The process of claim 3 wherein said ammonium salt is ammonium nitrate, ammonium sulfate or ammonium chloride.

5. The process of claim 1 wherein said inorganic oxide is calcined prior to contact with said fluoride at a temperature of 200°C to 600°C.

6. A process for enhancing the activity of an inorganic oxide according to any one of claims 1 to 5 substantially as hereinbefore described with reference to the Examples.

7. A method for converting an organic compound at conversion conditions with a catalyst comprising an inorganic oxide having enhanced activity and obtained by a process in accordance with any of claims 1 to 6. ( Zy j$&/thelr authorised Agsntti-, A, J. PARK &. SON. ror^J) —