US1960206A - Process for the production of motor fuels - Google Patents

Description

y 1934-" w. J. EDMONDS 60,206

PROCESS FOR THE PRODUCTION OF IOTOR FUELS Filed Jan. 1'7. 1931 Patented May 22, 1934 PROCESS FOR THE PRODUCTION OF MOTOR FUELS,

William John Edmonds, Baytown,

to Standard I. G. Company,

Delaware Tex aollxnor a corporation of Application January, 1931, Serial No. 509,369

3 Claims.

The present invention relates to an improved process for obtaining high grade gasoline from heavier hydrocarbon oils and more specifically to an improved hydrogenation process. My inven- 5 tion will be fully understood from the following description and the drawing.

The drawing is a diagrammatic figure in elevation of an apparatus which is suitable for carrying out my improved process and indicates the preferred apparatusand the fiow of materials through the process. v

In producing motor fuels from heavier hydrocarbons it is extremely important to produce a balanced gasoline that is a gasoline which has the proper amounts distilling at intermediate points, for example at 212 and at 284 F., as well as the proper initial and final boiling points. It is often very difiicult to produce a gasoline with the proper fill and in consequence large amounts of light hydrocarbons must be obtained from an extraneous source and must be blended with the product obtained from the higher boiling hydro carbons in order to produce a marketable fuel. It will be understood that the distillation specifications for marketable fuel vary according to conditions under which the gasoline is to be used and also vary generally from time to time according to changes in the design of internal combustion engines. While this process may be used to produce a gasoline with the proper fill according to widely varying specifications, it is understood that the distillation.specifications for fuels now considered marketable require a minimum of about 20% by volume of liquid distillate at 212 F. and about 50% at 284 F., for motor fuels having a final boiling'point of 100 to 450 F.,-as described according to the A. S. T. M. specifications No. D 86-27 adopted 1927. p

In ordinary refinery practice at the-present time considerable amounts of a heavy naphtha which may be generally described as a product boiling at about 300 F. to 450 F. and perhaps 500 F. are available. This material may be used as a motor fuel if blended with a sufficient quantity of light ends such as casinghead gasoline or other liquefied hydrocarbons obtained from refinery of cracked gases. This fuel, however, is usually characterized by an excess of low boiling compounds say at 212 or 221 F. and an excess of the higher boiling products boiling at 350 F. or

above and generally the fill at 284 F. is insufiicient for the best grades of naphtha.

The present invention while adapted to produce high grade motor fuels from all types of higher boiling vaporizable stocks is particularly adapted to the use of heavy naphtha suchas is described above-whereby motor fuels of a ,balanced boilingrange, good color and color stability are produced, together with low gum forming tendencies and marked anti-detonation properties. When heavy naphthaof the proper boiling ranges as specified above is'used as feed stock, the product is a marketable 'fuel meeting the distillation specifications already described and does not require additional blending of lighter boiling hydrocarbons.

' Referring to the drawing a light hydrocarbon oil such as heavy naphtha, for example, is drawn from any suitable source (not shown) through a feed line 1 and is forced by a pump 2 to a heat exchanger 3. High pressure hydrogen is also withdrawn from any suitable source by line 4 and is preferably mixed with the oil prior to flow through the exchanger 3. The preheated mixture then proceeds through line 4' to a heating coil 5 which is mounted in any suitable furnace 6. The furnace is adapted to raise the flowing stream of gas and liquid to an elevated temperature say in excess of about 800 or 900 F. The gas and liquid is then discharged through line 7 into a reaction chamber 8 which is adaptedto withstand pressures in excess of 20 atmospheres and preferably in excess of 200 atmospheres. The vessel 8 is preferably constructed of materials capable of withstanding the corrosive eilects of 8d the reactants and may be covered with an insulating layer 9. Catalytic material 10, the nature of which will be described below, is packed into, the reactor vessel in the form of small cubes or other convenient shapes on grids or similar supporting means 11. Material flows from the oven by line 12 which discharges into a second oven 13 preferably by way of heating means 14 which may be in the form of a heating coil similar to coil 5. The second vessel may be similar in all respects to vessel 8, with insulating covering 9', catalyst 10', and catalyst support 11, or it may be adapted to withstand-even more severe conditions of temperature and may be packed with a catalyst similar to that in vessel 8 or with other suitable catalysts which will be described below. If

desired, vessels 8 and 13 may be heated directly by internal heaters or by other suitable means, although I have found it preferable to heat by means of heating. coils without other direct application of heat to the reaction vessels. The material removed from vessel 13 is conducted by line 15 to the exchanger 3 and thence to acooler 16 and to a separator drum 17 from which condensed liquid is removed by a line 18 to any con- 10 venient storage (not shown). Gases uncondensed by the cooler 15 find exit from the upper portion of the trap 17 and are preferably purified in a purification chamber 19 prior torecirculation through the apparatus. Purified gases are forced by the booster pump 20 into the line 4- which conducts the hydrogen to the exchanger 3 as above described. A'portion of the fresh hydrogen may be removed from line 4 by pipe 21 and may be added in regulated quantities to the two ovens 8 and 13, by branch lines 22 and 23.

In the operation of my improved process the reaction is carried out in two or more stages of which only two have been shown in the drawing for purposes of illustration. A vaporizable hydrocarbon oil such as heavy naphtha, kerosene distillate or light gas oil is heated to a temperature in excess of about 800 F. and preferably below about 925 F. Pressure is above about 20 or 100 atmospheres and is preferably about 200 atmospheres. The time of contact in the first zone of the reaction varies somewhat, but the feed rate is preferably between the limits of 0.5 and 3.0 volumes of oil per volume of catalyst space per hour, based on the inlet oil at atmospheric temperature and pressure. The volume of hydrogen may vary between the limits of 2000 and 10,000 cubic feet per barrel of oil. Vapors flowing from the oven need not be condensed before the secondary treatment which is accomplished at a higher temperature in excess of about 950 F. and preferably not more than about 1000 F. The time of contact. in the second zone is, of course, adjusted with relation to temperature and ordinarily the feed rate should be not less than 1.0 to 3.0 volumes of, oil per volume of catalyst space per hour.

The catalytic materials used in my process preferably are such as exert hydrogenating influence although they may be compounds or mixtures of materials which exert not only hydrogenating, but also cracking influence. Of the materials of thefirst class, the sulphides, oxides or nitrides of the metals of the VI group are the most important and may be used alone or mixed with other materials. The alkaline earths, rare earths, or earth metal oxides, are examples of the second group and these maybe used alone or with inert materials such as clay, or active carbon and the like. If desired, mixtures of hydrogenating and cracking catalytic materials may be used as will be understood, preferably such as are immune to sulphur poisoning. Such catalysts may be conveniently classified as sulfactive catalysts. The same catalyst may be used in both zones, but it is preferred to use one in the prir'riary zone of predominantly hydrogenating influence; such as a mixture of molybdenum and chromium oxides. Catalyst in the secondary zone may possess considerable cracking as well as hydrogenating influence.

I have found that light hydrocarbon materials such as heavy naphtha, which are not ordinarily used as feed stocks for cracking or destructive hydrogenation processes, and especially those that contain large quantities of olefins and which are 'rich in sulfurous compounds, may be converted into high grade motor fuels which are stable in respect to gum and color. A motor fuel which is possessed of marked anti-detonation qualities may be produced from such feed stocks by the two stage method of conversion which consists in a longer reaction period at alower temperature belowabout 925 F. and a considerably shorter period at a higher temperature. Temperature and time in the first reaction stage are adjusted carefully so that there is substantially a complete'conversion of sulfurous material into hydrogen sulfide and at least a partial saturation of the unsaturated linkages. There may be at the same I time a considerable reduction in boiling point. The second stage treatment which is at a higher temperature completes the reaction with the Gravity ..42.9 A. P. I. Sulfur 0.498% Color Amber Initial boiling pt .252 F. Percent at 284 F 4- Percent at 374 F '76 Percent at 392 F 84 Final boiling pt 46'l F.

This materialis mixed with hydrogen in proportion of about 2000 to 2500 cubic feet of hydrogen per barrel of oil and passed through a primary reaction zone at a feed rate of about 1.1 vol/vol/hr. and at 850 to 900 F. using a catalyst composed of tungstic acid and magnesia. The vapors flowing from the oven are passed into the second zone without intermediate condensation or separation of constituents. The second zone is maintained at a temperature of about 1000 F. with a catalyst similar to the one used in the first zone. The feed rate is about 1.7. vol/vol/hr. and the product removed therefrom is condensed and the liquid is separated from the gas. The liquid product is then rerun and cut to 400 F. end point and has the following characteristics:

Gravity 51 A. P. I. Sulfur Below 0.01% Initial boiling pt. About 100 F. Final boiling pt "400 F.

Percent 0 212 F. 28

Percent 284 F 56 Y Color 26 (water white) Copper dish gum 6 mm/100 cc.

The yield of gasoline is about 80% of the oil fed by volume. The gasoline has anti-detonation qualities equivalent to a blend of sweet gasoline from mid-continent crude to which 40% of pure benzol has been added. On standing in the sunlight the gasoline shows no discoloration or tendency to form gum after two or three weeks or longer. It should be particularly noted that in this case a gasoline perfectly stable and of the 1. Process for producing valuable motor fuels of balanced boiling range with an end point of between about 400.F. and 450 F. and having 1,980,208 at least 20% distilling at 212 F. and 50% at 284 F., of high stability and marked anti-detonation properties which comprises passing a hydrocarbon distillate boiling between about 300 and 450 F. and of olefinic or largely unsaturated character with an excess of hydrogen at a pressure above about 100 atmospheres and at a temj perature between 850 and 925 F. through aprimary reaction zone containing a sulfactive hydrogenation catalyst at a rate between 0.5 and 3.0'volumes of oil per volume of catalyst per hour, and then through a secondary reaction zone containing a suitable sulfactive catalyst of hydrogenating and cracking influence at a feed rate between 1.0 and 3.0 volumes per volume per hour and at a higher temperature below about 1100 'F., condensing the product and segregating a fraction having an end point from 400 to 450 F'.

2. An improved process for obtaining high quality motor fuel from olefinic or largely unsaturated hydrocarbon distillates boiling in the range of hydrocarbons of the class of heavy naphtha, kerosene and light gas oil by destructive hydrogenation in the vapor phase, comprising the steps ofpassing the oil in vapor phase with hydrogen under pressure of at least 20 atmospheres through a primary reaction' zone containing a sulfactive hydrogenation catalyst at a temperature of about 850 to 925 F. and at an oil feed rate of about 0.5 to 3.0 volumes of oil per volume of catalyst per hour, interadjusting the operating conditions to secure removal of the greater part of the sulfurous impurities and a considerable reduction in boiling range of the oil with at least a partial saturation of the un-' saturated linkages passing the products-from this zone at a higher rate through a secondary zone maintained at a higher temperature below about 1000" F. for a time sumcient to complete the formation of products boi1ing in the motor fuel range.

3. An improved process for producing high quality motor fuel from distillatesof the type of heavy naphtha, kerosene and light gas oils, comprising passing the oil through two successive reaction zones containing a hydrogenation catalyst of the sulfactive type in the presence of WILLIAM JOHN EDMONDS.

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