US1767363A - Art of preparing hydrocarbon products - Google Patents

Description

June 24, 1930. M. a. HOPKINS ART OF PREPARING HYDROCARBON PRODUCTS Filed Aug. 16. 1922 QYRNY QMD EQ HER WW avweuboz Ybxwon Y). HoPNNs QMM W leum, for example,

Patented June 24, 1930 UNITED STATES PATENT. OFFICE DEVELOPMENT COMPANY, A CORPORATION 01' DELAWARE ART 0]! PREPARING HYDROCAREON PRODUCTS Application filed August 16, 1922. Serial No. 582,188.

My invention relates to the art of preparing hydrocarbon products, and will be fully understood from the following description and the drawing which is a semi-diagrammatic view in elevation of an apparatus suitable for carrying out my process.

In working up hydrocarbons, such as petroleum, oils from shale, lignite and low temperature coal retorting, pine oils, etc., by the usual methods of distillation, the intermediate fractions obtained are in general of less utility than the lighter and heavier fractions. The light fractions from petroin their capacity as motor fuel, and the heavy (lubricating) fractions are especially valuable, while the intermediate fractions, burning oils and gas oils are much less so. With a view toward obtaining additional yields of motor fuel out of such aforesaid intermediate fractions, cracking processes have been brought forward. These, however, are not only under the dis advantage of calling for high pressures and temperatures, but where commercially practicable require, moreover, as stocks, carefully selected heavy gas oils. My invention on the other hand, is not only applicable to stocks which are not suitable for cracking, converting them into more valuable products, but is also free from the operating difficulties and hazards of high pressures and temperatures, as in cracking processes.

In practicing my invention, various stocks may be used, depending upon the particular products desired. The hydrocarbon is passed through a heating zone in vapor form, to-' gether with proportioned amounts of air, the particular apparatus being immaterial, so long as the surfacesare non-reactive. The reaction which appears to be in the nature of a dehydrogenation, is carried on without the formation of appreciable amounts of oxygencontaining hydrocarbons, as the aim is not to make oxygen-containing derivatives, but improved hydrocarbon products especially olefins and other unsaturated hydrocarbons in substantial amounts. In general, the air feed is gaged to avoid generation of heat sufficient to carry the temperature above the limits desired; and I ordinarily prefer an air feed within the range of 5 to 20 cu. ft. per pound of hydrocarbon. The temperature is kept below the commercial cracking range which ordinarily is about 725875 F. and is maintained between the limits of 300 and 650 F. depending somewhat upon the particular stock being treated. Steam may be introduced as a temperature modifier, if desired, and is particularly useful if oxygen, undiluted instead of air, be employed. Pressure is maintained substantially atmospheric, or with some stocks of higher vaporizing point, an exhauster may be put on. the condenser line so as to reduce the pressure sufiiciently to hold the temperature below the cracking range. From the heating zone the vapors pass to a condenser system. Where desired the products may be treated to remove certain gumming constituents, for example, by being thoroughly washed in water, or preferably treated with steam or distilled with steam and treated with an alkali solution or with sulphuric acid and washed. The products obtained are useful for motor fuel, flotation oils, varnish and paint vehicles and oil substitutes, etc., depending upon the stock used and the extent of treatment.

As an illustrative example: One stock I have used was a distillate from mid-continent crude petroleum, having a gravity of 433 B., an initial boiling point of 300 F., 20% off at 373 F., 50% off at 414 F., and

80% oil at 476 F. I vaporized the oil and passed the vapors together with air through conduits heated externally to impart to the vapors a temperature of 520 to 550 F., the air feed being at the rate of 11.5 cu. ft. per pound of oil. The products were recovered in a water-cooled condenser and had a gravity of 26.9 B., an initial boiling point of 150 F., 20% off at 363 F., 50% off at 410 F., and 80% off at 462 F., and an acid absorption (in concentrated sulfuric acid) of 34%. The product, distilled in steam and treated with a 1% solution of sodium'hydroxid and finally washed with water, when used in a gasoline engine was equal as regards .anti-knock properties to much lighter fractions.

mmon B. HOPKINS, OF ELIZABETH, NEW JERSEY, ASSIGNOR TO STANDARD OIL In some cases the air may be introduced at successive points in desired amounts or the products may be passed through the air and heat zone again or through a further air and heat zone.

As an example of an apparatus suitable for carrying out my process, I provide a still 1 with a feed line 2 and a residuum draw ofi' 3. -The still is heated in the usual manner and vapors are conducted by the line 4 to a conversion chamber 6, which is adapted to maintain the temperature of the vapors. The coil or chamber 6 within the setting 5 is fitted with valved connections a, 5, and 0, so. that the oxidizing gas supplied by pump 7 and.line 8, may be admitted at more than one part of the coil 6. Vapors are discharged to a rectifying column 9 with partial condenser 10 and steam spray 11. Condensate may be withdrawn and returned if so desired, to still 1 by line 12, while vapors are removed by line 13 to condenser 14. The gas is separated from the condensed liquid in tank 15, the former drawn oif by line 16 and the latter flowing by pipe 16 through the pump 17 which passes the liquid through a mixer 18. The treating solution, which may be caustic soda, is admitted to mixer 18 by line 19 and the treated oil is settled and withdrawn from the separator tank 20 by line 21 to storage. The soda is withdrawn by line 22. The treating system may be widely different from that disclosed which however has been found to be satisfactory.

While in describing my invention I have referred to certain specific examples of procedure, uses, etc., it will be understood that these are illustrative and in no sense limitative. Nor is the invention to be understood as dependent upon the accuracy of any theory or reasons suggested to explain the advantageous results. On the contrary, the invention is to be regarded as limited only as defined in the following claims, in which it is my intention to claim all inherent novelty as broadly as the prior art permits.

What I claim is:

1. The process of preparing hydrocarbon products rich in unsaturates, which comprises passing a vaporized intermediate-petroleum fraction at substantially atmospheric pressure together with air through a temperature zone of about 550 F., the proportion of air being between 5 and 20 cubic feet per pound of hydrocarbon, collecting condensible prod ucts and removing gumming constituents from said products by distilling said products with steam and treating with dilute'alkali solution.

2. The process of preparing hydrocarbon products rich in unsaturates, which comprises passing petroleum hydrocarbon vapor at substantially atmospheric pressure together with air through a temperature zone between 300 and 650 'F., the proportion of air being hetween 5 and 20 cubic feet per pound of hydrocarbon, collecting condensible products and removing gumming constituents from said products by distilling said products with steam and treating with dilute alkali solution.

3. The process of preparin hydrocarbon products rich in unsaturates, w ich comprises passing hydrocarbon-vapor at substantially atmospheric pressure together .with air through a temperature zone between 300 and 650 F., the proportion of air being between 5 and 20 cubic feet per pound of hydrocarbon, collecting condensible products, and treating said products to remove gumming c'onstitu- F. to non-catalytic reaction with oxygen in the proportion of from 1 to 4 cubic feet of available oxygen per pound of hydrocarbon.

6. The process of partially dehydrogenat ing hydrocarbon vapors comprising passing the vapors with air through a dehydrogenation zone at a temperature between the approximate limits of 300 and 650 F.,whereby a substantial proportion of unsaturated hydrocarbons is formed without formation of substantial quantities of compounds of carbon, hydrogen, and oxygen and without substantial polymerization.

7. The process of partially dehydrogenating petroleum distillates, comprising vaporizing the distillate, passing the vapor with a limited quantity of air through a zone of dehydrogenation, maintaining temperature therein between 300 and 650 F., whereby a substantial quantity of unsaturates are formed without formation of appreciable amounts of compounds containing oxygen, carbon, and hydrogen and without substantial polymerization.

. MARION B. HOPKINS.

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