US3114698A

US3114698A - Olefinic hydrocarbons

Info

Publication number: US3114698A
Application number: US158228A
Authority: US
Inventors: Prentiss S Viles
Original assignee: Exxon Research and Engineering Co
Current assignee: ExxonMobil Technology and Engineering Co
Priority date: 1961-12-11
Filing date: 1961-12-11
Publication date: 1963-12-17
Anticipated expiration: 1980-12-17

Description

Dec. 17, 1963 P. s. VILES OLEFINIC HYDROCARBONS Filed Dec. 11, 1961 CARBON MONOXIDE AND WATER OLEFINIC HYDROGARBON REACTION ZONE CATALY$T BOTTOM S FRACTION INVENTOR PRENTISS S. VILES United States Patent Ofi 3,114,698 Patented Dec. 17, 1963 ice 3,114,698 OLEFINIC HYDROCARBONS Prentiss S. Viles, Baytown, Tex., assignor, by mesne assignments, to Esso Research and Engineering Company, Elizabeth, N.J., a corporation of Delaware Filed Dec. 11, 1961, Ser. No. 158,228 7 Claims. (Cl. 203-137) The present invention is directed to a method for improving olefinic hydrocarbons. More particularly, the invention is concerned with the treatment of olefinic hydrocarbons to improve the octane number thereof. In its more specific aspects, the invention is concerned with conversion of olefinic hydrocarbons.

The present invention may be briefly described as a method for improving olefinic hydrocarbons in which an olefinic hydrocarbon in admixture with carbon monoxide and water vapor is contacted with a Fischer-Tropsch catalyst at a temperature within the range from about 400 F. to about 800 F., and at a pressure from about 50 to about 750 pounds per square inch gauge to form a treated product which is then recovered.

The feed hydrocarbon is an olefinic hydrocarbon such as one boiling within the range from about 100 F. to about 450 F. It is contemplated that the oleiinic hydrocarbon may be a pure olefin such as heptene, octene, nonene, decene, dodecene, and the like, or mixtures thereof. The olefinic hydrocarbon may suitably be a cracked petroleum fraction such as one boiling in the range from about 100 F. to about 450 F. or a polymerized olefinic fraction. Catalytically cracked fractions are also suitable feed stocks for the present invention.

Temperatures employed may range from about 400 F. to about 800 F. with temperatures within the range from about 450 F. to 550 F. preferred.

Pressure may range from about 50 to about 750 pounds per square inch gauge with a preferred pressure being within the range from about 100 to about 500 pounds per square inch gauge.

Liquid space velocities of the olefinic hydrocarbon are suitably within the range from about 0.1 to about 5.0 volumes per volume of catalyst per hour (v./v./hour). The gas space velocity of the mixture of carbon monoxide and water vapor may suitably range from about 10 to about 100 volumes per volume of catalyst per hour (v./v./hour).

The gasiform mixture of carbon monoxide and water may be employed in ratios within the range from about 10:1 to about 1:10. A preferred ratio of carbon monoxide to water is 2:1.

Catalysts employed in the present invention are the Fischer-Tropsch catalysts of which many are known. Exemplary only of Fischer-Tropsch catalysts are cobalt, thorium, iron, nickel, ruthenium, manganese, tungsten, uranium, copper, potassium, magnesium, aluminum, zirconium and cerium usually in the form of the oxides or mixtures of the oxides. Cobalt, thoria and magnesia comprise a suitable catalyst.

The present invention will be illustrated by reference to the drawing in which the single FIGURE is a flow diagram of a preferred mode.

Referring now to the drawing, numeral 11 designates a charge line by way of which an olefinic hydrocarbon such as a cracked naphtha boiling within the range from about 200 F. to about 325 F. is charged from a source (not shown). A gasiform mixture of carbon monoxide and water is introduced into line 11 from line 12, controlled by valve 13, and the olefinic hydrocarbon and the gasiform mixture are discharged into a heating zone 14 comprising a heating coil 15 to which heat is supplied from gas burners 16. The olefinic hydrocarbon and gasiform mixture are raised to reaction temperature in the heating zone 14- and the heated reactants are discharged therefrom by way of line 17 into a reaction Zone 18 containing a bed of catalyst 19 of the type illustrated, supra.

In reaction zone 18 conditions are selected to treat the olefinic hydrocarbon and the reaction product is discharged from the zone 18 by line 20 into a distillation zone 21 which may be a modern fractional distillation tower equipped with all auxiliary equipment for precise separation of the components of the treated product.

For purposes of illustration only, zone 21 is shown as provided with a heating means illustrated by steam coil 22 for adjustments of temperature and pressure. The treated hydrocarbon is removed as an overhead fraction from zone 21 by line 23; whereas, a bottoms fraction is discharged by line 24. The treated hydrocarbon withdrawn by line .23 is suitable for use as a motor fuel or may be treated further, such as by distillation, to separate isoparaflins and olefins from the treated product. For example, isomerized olefins may also be recovered from the treated product.

The present invention will be further illustrated by an operation in which a catalytically cracked naphtha boiling within the range from 230 F. to 310 F. was contacted with a catalyst containing 31.5% cobalt oxide, 6% thorium oxide, 1.2% magnesium oxide and 61.3% kieselguhr by weight employing a carbon monoxide and water vapor mixture. The reaction temperature was 500" F., the liquid flow rate of the naphtha fraction was 0.25 v./v./hour, reaction pressure was 100 pounds per square inch gauge, and the carbon monoxide-water vapor mixture flow rate was 35 v./v./hour. The composition of the carbon monoxide-water vapor mixture was two parts of carbon monoxide and one part of water. The liquid hydrocarbon contained 67% olefins and was passed over the catalyst under the conditions set out, supra. The liquid volume of the hydrocarbon product recovered amounted to approximately 105% of the liquid volume of the feed stock. The results obtained are presented in the following table:

Table II 095% 011 Hydro- Fraction carbon Total From Charge Liquid Distillation Stock Product of Total Liquid Product Aromatics, Percent 18. 7 16. 0 18. 8 Olefins, Percent 67.2 63. 3 64.1 Saturated Hydrocarbons, Percent 14.1 20. 7 17. 1 Bromine No 98.0 96. 9 94. 7 Sulfur, Percent 0. 040 0.0331 0.031

242 240 245 302 328 299 246 247 248 249 250 250 252 252 252 255 256 254 257 258 256 260 260 259 262 263 261 265 266 265 270 272 269 on at, F 276 281 275 oil at, F 280 293 281 The leaded (3 cc. TEL/ gal.) octane blending characteristics of these samples are shown below:

1 Average of two determinations. Z Blended, 25% samp1e+75% of 94 Motor octane (leaded) base stock.

From these data it will be clear that a marked improvement amounting to 3.4 motor octane units was obtained for the gasoline treated in accordance with the present invention.

It is indeed surprising that a gasiform mixture of carbon monoxide and water should be suitable for treatment of olefinic hydrocarbons to improve the octane number thereof.

The present invention is quite advantageous and useful and allows the obtaining of treated fractions having improved characteristics. The invention also allows the recovery of isoparaffins and olefins from the treated product.

The nature and objects of the present invention having been completely described and illustrated and the best mode thereof set forth, what I wish to claim as new and useful and secure by Letters Patent is:

1. A method for improving olefinic fractions which consists in contacting an olefinic hydrocarbon and a gasiform mixture of carbon monoxide and water With a Fischer-Tropsch catalyst at a temperature within the range from about 400 F. to about 800 F. and at a pressure within the range from about 50 to about 750 pounds per square inch gauge to form a treated product and recovering said product, a liquid space velocity from about 0.1 to about 5.0 v./v./ hour being employed for the olefinic hydrocarbon and a gas space velocity from about to about 100 v./v./hour being employed for the gasiforrn mixture.

2. A method for improving olefinic fractions which consists in contacting an olefinic hydrocarbon boiling in the range from about 100 F. to about 450 F. and a gasiform mixture of carbon monoxide and water with a Fischer-Tropsch catalyst at a temperature within the range from about 400 F. to about 800 F. and at a pressure within the range from about 50 to about 750 pounds per square inch gauge at a liquid space velocity for the olefinic hydrocarbon from about 0.1 to about 5.0 v./v./ hour and a gas space velocity for the gasiform mixture from about 10 to about 100 v./v./hour to form a treated product and recovering said product.

3. A method for improving olefinic fractions which consists in contacting an olefinic hydrocarbon boiling in the range from about 100 F. to about 450 F. and a gasiform mixture of carbon monoxide and water in a ratio within the range from about 10:1 to about 1:10 with a supported Fischer-Tropsch catalyst at a temperature with- 4 in the range from about 400 F. to about 800 F. and at a pressure within the range from about to about 750 pounds per square inch gauge at a liquid space velocity for the olefinic hydrocarbon from about 0.1 to about 5.0 v./v./hour and a gas space velocity for the gasiform mixture from about 10 to about v./v./hour to form a treated product and recovering said product.

4. A method in accordance with claim 3 in which the ratio of carbon monoxide to hydrogen is 2: 1.

5. A method for improving olefinic fractions which consists in contacting an olefinic hydrocarbon boiiling in the range from about 100 F. to about 450 F. and a gasiforrn mixture or" carbon monoxide and water with a supported cobalt oxide, thorium oxide, magnesium oxide Fischer-Tropsch catalyst at a temperature within the range from about 400 F. to about 800 F. and at a pressurewithin the range from about 50 to about 750 pounds per square inch gauge at a liquid space velocity for the olefinic hydrocarbon from about 0.1 to about 5.0 v./ v./ hour and a gas space velocity for the gasiform mixture from about 10 to about 100 v./v./hour to form a treated product and recovering said product.

6. A method in accordance with claim 5 in which the catalyst comprises 31.5% by weight of cobalt oxide, 6% by weight of thorium oxide, 1.2% by weight of magnesium oxide and 61.3% by weight of kieselguhr.

7. A method for improving olefinic fractions which consists in contacting an olefinic hydrocarbon boiling in the range from about 100 F. to about 450 F. and a 2:1 gasiform mixture of carbon monoxide and water with a supported cobalt oxide, thorium oxide, magnesium oxide Fischer-Tropsch catalyst at a temperature Within the range from about 400 F. to about 800 F. and at a pressure within the range from about 50 to about 750 pounds per square inch gauge at a liquid space velocity for the olefinic hydrocarbon from about 0.1 to about 5.0 v./v./hour and a gas space velocity for the gasiform mixture from about 10 to about 100 v./v./hour to form a treated product and distilling said product.

References Cited in the file of this patent UNITED STATES PATENTS 2,098,400 Pier et al. Nov. 9, 1937 2,443,673 Atwell June 22, 1948 2,486,243 Atwell et al. Oct. 25, 1949 2,538,248 Ipatiefi et al. a Jan. 16, 1951

Claims

7. A METHOD FOR IMPROVING OLEFINIC FRACTIONS WHICH CONSISTS IN CONTACTING AN OLEFINIC HYDROCARBON BOILING IN THE RANGE FROM ABOUT 100*F. TO ABOUT 450*F. AND A 2:1 GASIFORM MIXTURE OF CARBON MONOXIDE AND WATER WITH A SUPPORTED COBALT OXIDE, THORIUM OXIDE, MAGNESIUM OXIDE FISCHER-TROPSCH CATALYST AT A TEMPERATURE WITHIN THE RANGE FROM ABOUT 400*F. TO ABOUT 500*F. AND AT A PRESSURE WITHIN THE RANGE FROM ABOUT 50 TO ABOUT 750 POUNDS PER SQUARE INCH GAUGE AT A LIQUID SPACE VELOCITY FOR THE OLEFINIC HYDROCARBON FROM ABOUT 0.1 TO ABOUT 5.0 V./V./HOUR AND A GAS SPACE VELOCITY FOR THE GASIFORM MIXTURE FROM ABOUT 10 TO ABOUT 100 V./V./HOUR TO FORM A TAREATED PRODUCT AND DISTILING SAID PRODUCT.