US2423163A - Conversion of hydrocarbons - Google Patents

Description

Patented July 1947 "fooNvaas IoN 2,423,163 a a a OF HYDROCARBON S Charles L. Thomas, Western Springs,

111., assignor to Universal Oil Products Company, Chicago,

. 111., a corporationof Delaware No Drawing. ApplicatlonOctober 31, 1944, i

3 Serial No. 561,319 9 Claims. (01. 19 6 j52) This invention relates particularly to the conversion of hydrocarbons in the presence of a specially prepared catalyst.

In a broad aspectjthe present invention relates to a hydrocarbon conversionprocess which comprises subjecting said hydrocarbon to conversion in the presence of a catalyst comprising a mechanical mixture of a suitable supporting a material and sublimed molybdenum oxide.-

In one specific embodiment, the present invention relates to a hydrocarbon conversion process which comprises subjecting said hydrocarbon to conversion at a temperature within the range of about '600? to about 1200 F. in the presence of a catalyst comprising a mechanical mixture of alumina and sublimed molybdic oxide. 7 I Q The broad scope of the present invention contemplates the conversion of hydrocarbons in the presence of a specially prepared catalyst and the particular catalytic reactions to, be effected in any given operation will dependupon the charging stock to the process and the conditions of operation employed. The presentinventionis particularly applicable to the type of process known as hydroforming. In this process gasoline or naphtha of relatively low anti-knock characteristics is subjected to treatment in the presence of the catalyst at a temperature within the range of about 900 to about 1100 F. and a superatmospheric pressure of about 50to about 2000 pounds per square inch or more. .Inthe hydroforming process, hydrogen, either from an external source or recovered from within the process, is supplied to the reaction zone, but there is no net consumption of hydrogen. and in fact the quantity of hydrogen produced exceeds the quantity thereof consumed in the process. In this process aromatic hydrocarbons are produced to a considerable extent, The invention also is applicable to the reforming of gasoline or naphtha under substantially the same conditions but inthe absence of added or recycled hydroge a 1 Another process contemplated by the present invention is hydrocracking, in which operation an oil boilin above the range of gasoline is subjected to contact with the catalyst in the presence of hydrogen at a temperature. within the range of about 800 to about 1000? Hand pressures ranging from atmospheric to- '1000 pounds per square inch or more. In this process, there usually is a net consumption of hydrogen, and the primary desired product is gasoline of high anti-knock characteristics.

and particularly gasoline to remove undesirable impurities and particularly sulphur. Desulphurence of the catalyst at a temperature within the range of from about 600 to about 700 and, in some cases, as high as 750 F., at atmospheric or slightly superatmospheric pressures which generally are not in excess of about 50pounds. It is also within the scope of the invention to eiiect the refining treatment in the presence of hydrogen.

The hereinbefore' recited processes are. examples in which the charging stocks to the process comprise a mixture of hydrocarbons. The presentyinvention is also applicable to the treatment of a more selected charging stock to eiiect dehydrogenation and/or dehydrocyclization reactions, For example, pentane may be subjected to treatment in the presence of the catalyst to effect dehydrogenation thereof into .amylene.

Similarly, hexane may be subjected to conversion in the presence of the catalyst to form hexylene and/or benzene. Likewise, heptanes, octanes, nonanes, etc., may be similarly subjected to treatment to form the corresponding olefin and/or aromatic hydrocarbon. In addition, mono-olefinic hydrocarbons may be subjected to treatment in the presence of the catalyst to form the corresponding di-olefinic hydrocarbons. The dehydrogenation and/or dehydrocyclization reactions may be efi'ectedgwithin the broad temperature range of about 800 to about 1200 F., and, under low pressures which may be subatmospheric, atmospheric or moderately superatmospherio. generally not in excess of about 50 pounds per square inch. .The particu-w .55 An example of another process contemplated by the present invention is the refining, of oil lar temperature to be employed in any given operation will depend upon the specific charging stock to the process and the products desired.

It is understood that, when selecting the particular temperature and pressure to be employed in any given operation, the time of contact must also be considered, as well as the activity of the particular catalyst being used. The activity of the catalyst will depend somewhat on the specific method of manufacture as will be hereinafter set forth, In addition, it is understood that the reactions hereinbefore set forth are typical of thosecomprised within the scope of the present invention and that many, if not all, of these reactions may occur to some extent in any partioular operation of the process.

As he'reinbefore set forth, the primary feature of the-present invention is the usein the con-.

version of hydrocarbons of a specially prepared catalyst comprising a mechanical mixture of a suitable supporting material and sublimed molybdenum oxide. In the ordinary manufacture of catalysts containing molybdenum oxide, it is the practice to prepare such catalysts from cornmercially available molybdic oxide (M003). Since this oxide as produced commercially is a coarse, dense material, it is the customary prac- 'lybdic oxide.

tice, when forming composite catalyst, to use the molybdic oxide in the form of a solution or to convert it into .another molybdenum compound and then use the molybdenum compound so prepared in compositing with the supporting material. It is apparent to those skilled in the art that the manufacture of composite catalysts in this way is an involved and expensive procedure. I have found that hydrocarbons may be converted in the presence of a. molybdenum oxide-containing catalysts prepared in a simpl and inexpensive method from sublimed mo- The sublimed molybdic oxide is a very light, fluffy powder that is extremely active. Because of the fine particles, the molybdic oxide may be evenly distributed upon the support merely by mixing the dry powders and pelletting. To illustrate the difference in the sublimed molybdic oxide and the ordinary mo lybdic oxide, the former has an apparent bulk. density of 0.138 gram per cc., as compared to an apparent bulk density of 0.795 gram per cc. for

the ordinary molybdic oxide.

In accordance with the invention the sublimed molybdic oxide is composited by mechanical mix-. ing with a supporting material. Any suitable porous supporting material may be used, including aluminum oxide, magnesium oxide, activated bentonite clays, activated montmorillonite clays, kieselguhr, etc. In preparing the supporting materials, some precautions arenecessary to insure that they possess the proper physical and chemical characteristics. For example, when using alumina, which is the preferred supporting material of the present invention, it is essential that it be of the gamma-alumina form and not of the inactive alpha form. The aluminum oxide may be obtained from natural oxide minerals, such as bauxite, or from carbonates, such as dawsonite, or it may be prepared by precipitation of aluminum oxide from solutions of aluminum salts such as aluminum sulphate, aluminum chloride, etc., and the precipitate subsequently dehydrated by heat.

As hereinbefore set forth, one of the primary advantages of the present invention is that the. e M v of-rosinwas added as a lubricant and the mixture}was pelletted. The rosin was removed by h catalyst may readily and cheaply be prepared by mechanically mixing of a commercially available aluminum oxide, such as grade A Activated Alu mina, in a dry powdered condition with sublimed molybdenum oxide. These mixed powders may then be used as the catalyst or preferably asuitable lubricant is added and the mixture is then pelletted or otherwise formed into granules.

Any suitable lubricant may be used to facili' tate pelletting of the powder and may comprise, for example, rosin, graphite, hydrogenatedcoicoanut oil, stearic acid, starch, etc.

However, it is also within the scope of the -invention to manufacture the composite catalyst by first preparing an alumina gel or hydrous precipitate by reacting a soluble aluminum salt with ammonium hydroxide or ammonium carbonate, or byreacting aluminum metal with a weak dilute acid to form an aluminum sol, which is coagulated by heat or a small amount of base, or by forming such a gel by other methods. The alumina gel in a wet or undried state is then intimately mixed with the molybdic oxide, the mixture dried and subsequently formed into desired shapes by pelletting or otherwise.

In general, the molybdic oxide will comprise from about 2 to about 40% of the composite catalyst. The activity of the particular catalyst will depend on the amount of molybdic oxide and on its specific method of manufacture. The best catalysts are obtained when molybdic oxide is vuniformly distributed throughout the support and itis therefore preferred that the mechanical mixing be eflicient. As hereinbefore set forth,

the powdered sublimed molybdi'c oxide is in a very fine state of subdivision and lends itself to ready uniform distribution throughout the composite catalyst mass.

The operation of the process is relatively simple and may take any of the conventional forms. Fixed bed processes areof the type in which the catalyst is disposed within tubes or chambers maintained under the desired temperature and pressure conditions, and the hydrocarbons passed over the catalyst. Fluidized operations comprise passing the hydrocarbon vapors in admixture with the catalyst powders through a reaction zone with a velocity regulated to obtain hindered settling in the reaction zone. In this type of operation the hydrocarbons pass through the reaction zone at a greater velocity than does the catalyst, the operation being controlled so that the catalyst may be removed from the lower portion of the reaction zone while the hydrocarbons are removed from the upper portion thereof. Another suitable type of operation isthe moving bed process in which the catalyst is passed countercurrently to the hydrocarbons. Still another type of operation is the suspensoid process in which the catalyst and hydrocarbons are admixed to form a slurry and the slurry is passed into the reaction zone.

It is understood that the present invention is not limited to any particular process flow and that any "suitable system for effecting the desired conversion may be employed.

The following example further illustrates the novelty and utility of the present invention.

a" Example The'catalyst was prepared by mixing 20 grams of sublimed molybdenum oxide, having an apparent-bulk density of 0.138gram per cc., and 20 grams of. powdered grade A Activated Alumina in a pebble mill. After mixing for an hour, 4%

in, all at 9 32 F. aplitha-having, an Engler initial boiling point 01'- .213 F;',.an end boiling point of 283 F., a brominefnumb'er of 0.3, a toluene content of 8.5%

by volume, and an A. S. T. M. octane number of 58 was subjected to hydroforming in the presence -.'ofl,the above catalyst and 3.5 moles of hydrogen 'per mole of naphtha at a temperature of 960 F.. a pressure of 1000 pounds per square inch and a jweighthourly space velocity of one. The space velocity is defined as the weight of naphtha per :hour "per weight of catalyst in the reaction zone. The products obtained are as follows:

Recoveries in weight per cent of charge:

The analysis of the liquid product boiling between 194 and 248 F. is as follows:

Refractive index at 20 C 1.4473

Bromine number 5 Wt. per cent of toluene 51.5

The volume per cent of toluene based on the a 2. A hydrocarbon conversion process which comprises subjecting said hydrocarbon to conversion in the presence of a catalyst comprising a mechanical mixture of gamma alumina and sublimed molybdic oxide.

'3. A hydrocarbon conversion process which comprises subjecting said lwdrocarbon to conversion at a temperature within the range of about 600 to about 1200 1".in the presence of a catalyst comprising a mechanical mixture of gamma alumina and sublimed molybdic oxide.

4. A hydrocarbon conversion process which comprises subjecting hydrocarbons boiling within the range of gasoline to reforming in the presence of a catalyst comprising a mechanical mixture of porous supporting material and sublimed molybdenum oxide.

5. A hydrocarbon conversion process which comprises subjecting hydrocarbons boiling within the range of gasoline to reforming at a temperature within the range of about 900 to about F., in the presence of hydrogen and a catalyst comprising a mechanical mixture of gamma aluminum oxide and sublimed molybdic oxide.

6. A hydrocarbon conversion process which comprises subiecting hydrocarbons boiling above the range ofgasoline to cracking in the presence of a catalyst corruirising a mechanical mixture of a porous supporting material and sublimed molybdenum oxide.

7. A hydrocarbon conversion process which comprises subjecting hydrocarbons boiling above the range of gasoline to cracking at a temperature within the range of about 800 to about 1000" F., in the presence of hydrogen and a catalyst comprising a mechanical mixture of gamma aluminum oxide and sublimed molybdic oxide.

8. A hydrocarbon conversion process which comprises subjecting said hydrocarbon to dehydrogenation in the presence of a catalyst come prising a mechanical mixture of a porous supporting material and sublimed molybdenum ox de.

9. A hydrocarbon conversion process which comprises subjecting said hydrocarbon to dehydrogenation at a temperature within the range of about 800 to about 1200 F., in the presence of a catalyst comprising a mechanical mixture of gamma aluminum oxide and sublimed molybdic oxide.

CHARLES L. THOMAS.

REFERENCES cr'rEn The following references are of record in the file of this patent:

UNITED STATES PATENTS