US2050025A - Method of treating hydrocarbon oils - Google Patents

Description

Aug. 4, 1936.

m. 1 j wmku m L1 Il.' \mw Y. n I.' O m, .QN EN mn hw .A||l Qwk N xa n m 5% @SL Xklbh .,...kvnw mi@ khxqvkv uw m. Y N# .W .hn l' mw. v i 4 .w Qms L@ L WM L K1 :H m hi lim. HHHHH SHH.. u. .|...HHH \m -MMU @WMU All n www..." hm. wh Yuvk DIKE I-I.. JULLIVAH BVAQOLD V. ATWELL ATTORNEY Patented Aug. 4, 1936 METHOD F HYDBOCABBON Pike H. Sullivan, New Rochelle, and Harold-V.

Atwell, White Plains, N. Y., assignors to Gasoline Products Company, Inc., Newark, N. J., a corporation of Delaware Application March 29, 1933, Serial No. 663,278

4 Claims. 4 (Cl. 196-54) The present invention relates to the conversion of relatively high boiling hydrocarbon oils into relatively low-boiling hydrocarbon oils such as gasoline suitable as fuel for internal combustion engines.

It is an object of our invention to provide an improved, process whereby hydrocarbon oil may be catalytically cracked with an economical use of the catalytic material.

A further object is the provision of a process wherein oil may be economically reduced to cokeby the aid ofa catalyst.

In accordance with our invention relatively heavy oil, which it is desired to convertl into lighter products particularly inthe gasoline boiling range, is brought in either highly heated or relatively cool condition, into contact with highly heated substantially inert gases or vapors in which a vaporized catalyst is present. These hot gases or vapors serve either to raise the oil to a cracking temperature from a relatively-coldstate or merely to maintain the temperature of lpreheated oil at a cracking value during a soaking or digesting period. Nitrogen, carbon dioxide or 25 combustion gases may be used as heat carrying gases. Reactive gases or vapors may also be used. These, for example, may comprise hydrocarbon gases, such as natural or casing head gases, or gases derived from a cracking operation, or relatively clean distilled oils in the vapor phase, such as naphtha stocks, kerosene, gas oil and the like. Hydrogen or carbon monoxide may also be used. The catalyst may be introduced into the heating fluid prior to its passage through a heating zone, wherein the fluid is raised to an oil cracking temperature, the catalyst being vaporized during its ilow therethrough. `Or the catalyst may be vaporized and introduced into the stream of heating'fiuid at an intermediate 40 point in the heating zone or beyond the heating zone. Alternatively' the fluid may rst be raised in temperature to the desired value or slightly in excess of that value and then mixed with a quantity of catalytic material either in dry form 5 or in the form of an oil slurry or magma. The catalyst is preferably a metallic halide such as aluminum chloride or ferrie chloride. Aluminum chloride is particularly well adapted for this purpose.

This process is especially well adapted for the cracking of relatively heavy hydrocarbons such as crude petroleum, reduced crude, or fuel oil, and is also adapted for the conversion of lighter products such as gas oil; or kerosene, into gaso- 55 une' The above mentioned and further objects and advantages of our invention and the manner of attaining them will be made clear in the following description taken in conjunction with the accompanying drawing. f

` The single figure of the drawing represents diagrammatically an oil cracking system embodying .our invention.

Referring more particularly to the drawing reference numeral I indicates agas heater; 2 10 a catalyst mixing chamber, 3 an equalizing chamber, 4 a cracking still, 5 a catalyst separator,

6 a fractionator and 'I .an oil heater. Fresh charging stock for the system, which may be, for example, 22 A. P. I. Mid-Continent reduced 15 crude, enters the system through charging line 8, and i`s forced by action of pump 9 either through the coils of oil heater I or instead through by-pass line I0, into the cracking still 4, wherein a pressure of from atmospheric to several hundred pounds per square inch, but preferably about 100 pounds to 200 hundred poundsA per square inch, may be maintained. The charging oil may be introduced into the top of the still through a spray head or distributor II preferably so arranged as to spray the oil downwardly without bringing it into contact with the still-walls, or the oil may be introduced into a lower level of the still through pipe i2. Valves I3 and I4 serve to regulate the flow of oil 30 into the cracking still, while valves I5, I6, and I1 are furnished to control the passage of the oil either through the heater 'I or around it in any desired quantities. The gas and/or vapors conf stituting the heating medium, for example, substantially inert gases such as products of combustion, nitrogen, or carbon dioxide, or reactive gases, such as incondensable hydrocarbon gases derived from a cracking operation or vapors formed from hydrocarbon liquids, are passed 40 through pipe line I8 into gas heater Il by action of pump I9. In order to avoid confusion in this description the heater I is called a gas heater. This application is not intended in a limiting sense, as any of the fluids mentioned as suit- .1,5

able catalyst carriers may be passed therethrough. i

These gases 0r vapors are raised to a temprature suitable for the cracking of hydrocarbon oil and are then transferred through line I 20 into the cracking still 4. The catalyst is introduced into the gas stream either before or after passage thereof through the gas heater, and may be injected in dry powder form or in the formof a slurry or magma made by mixing the catalyst with oil or other carrier. The slurry form is preferred. Reference numeral 2 indicates an agitator tank for making the slurry. The catalyst may be introduced into this tank 'through pipe 2l and light hydrocarbon oil or other carrier through pipe 22. An agitator or stirring mechanism 23 serves thoroughly to mix the catalyst and carrier to form the slurry which is drawn off through a. pipe 24. This slurry is then forced by pump 25 either into the inlet pipe I8 of the gas heater through pipe 26, or into the pipe 20 between the gas heater and the cracking still, by means of conduit 2l, valves 28 and 29 providing the necessary control for the introduction of the slurry. The equalizing chamber 3 is provided in order to afford suicient time of contact of the catalyst with the hot gases or vapors when the catalyst is introduced after the heating of those products to insure complete vaporization of the catalyst and thorough mixture thereof with the gases. Thirty (3S) indicates bafiie plates inside of the equalizing chamber for promoting more thorough mixing of the products. This equalizing chamber may be dispensed with 'if desired. The amount of catalyst required will vary with the temperature used and also with the character of the charging stock. Ten to twenty-five pounds of aluminum chloride may be used per barrel of charging stock, for example, the amount required at higher temperature being less than that required at low temperature.

The oil in cracking still 4, if in the liquid phase, is preferably maintained at an intermediate level above the point of connection of pipe 20 therewith so that the introduced gases or vapors are caused to bubble through the oil body, thereby causing agitation and thorough mixing of the hot gases and the catalytic vapors with the oil body. Contact may also be brought about with the oil when the latter is in the vapor phase. in this case the oil is rst vaporized in the heater 7, and the resulting vapors are preferably introduced into the still 4 through the line I2 in order to give increased contact with the hot gases from pipe 20 whereby the vapors are cracked by the heat of the hot gases and the vaporous catalyst. Another method of operating is to introduce either cold oil or oil preheated in heater 'I through spray nozzle II into the still while maintaining a low liquid level therein, or running to coke. In this case the droplets of oil formed by the spray-head or distributor Il fall downwardly through an upwardly rising current of heated gas or vapors containing vaporized catalyst, this current serving to retard the downward motion of the sprayed liquid during the cracking thereof. This method is particularly well adapted for the production of coke, the size of the droplets, height of the chamber, velocity of the rising gas, and degree of preheat being so regulated as to insure substantially complete evaporation and conversion to coke or pitch of the droplets by the time they reach the bottom of the cracking still. Heavy relatively dirty oil may be introduced directly into still 4 through line I0 when desired, the heat necessary for its conversion being provided either by products from heater I or heater 1. Distilled and/or cracked vapors pass overhead through the vapor line 3| into the catalytic separator 5, wherein the vapors are cooled by action of lytic material. 'I'his material is deposited in the bottom of the separator from which it may be removed at intervals. Thirty-three (33) indicates a drawofi:` line whereby any sludge or oil may be eliminated from the system. Vapors remaining uncondensed pass overhead through vapor line 34. into the fractionator 6 wherein separation thereof into a nal gasoline distillate and a heavier reflux condensate results. The gasoline vapors are taken off overhead through vapor line 35, condensed in condenser 35 and are collected in receiving drum 3l. From this drum the nished product'may be drawn oif through line 39 while a portion thereof may be returned, as a refiuxing medium, in the usual manner through pump-back line 39 under pressure of pump 4G. Incondensible gases resulting from the cracking operation separate from the distillate in the receiving drum 3.1 and may be removed in the usual manner through pipe I I. All or part of these incondensible gases may be used as the carrier gasintr'oduced through pipe t8 into the gas heater l, valved pipe 4I' being provided to transfer the gases to the heater inlet. The reflux condensate collecting in the bottom of the fractionator 6 may be drawn oif from the system through line 42, or may be returned through line 43 by action of pump 44, to be blended with the charging stock for the system. Valve 45 controls the draw-off line 42, and valve i6 controls the recycle line 33.

Condensate from fractionator 6 may be charged to the gas heater I through conduit 41 either with or without products introduced through pipe IB. These condensates may comprise light gas oil or heavy naphtha withdrawn from trap-out trays 48 and 49, respectively, of the fractionator. Likewise relatively heavy gas oil condensate from the base of the fractionator may be diverted through cross over pipe 50 to the conduit 4l, or a quantity of the gasoline distillate from receiver 3l may be diverted through cross over pipe I to conduit 4l for similar treatment. The condensates so introduced into the heater I may be heated to a. temperature either above or below their conversion temperature whereby they act merely as carriers for 1 the .catalytic material or are subjected to conversion themselves. Alternatively desired portions of the light gas oil, heavy naphtha or gasoline distillate may be passed through cross over line 50 into line 43 for heating, with or without conversion, in heater l, while heated, catalyst-containing inert or reactive gases and/or vapors are introduced into still 4 from heater I.

Other charging stock than that mentioned may be used if desired, for example, a clean gas oil charging stock may be cracked either in the liquid or vapor state, by the process described hereinbefore. Alternatively very heavy fuel oil or tar may be reduced to coke either by passing the hot catalyst carrying gases or vapors 'directly through a body of the liquid oil or tar maintained in still 4, or by spraying the latter material downwardly within still 4 against an upwardly rising current of the catalyst-containing hot gas and/or vapors from heater I, either with or without hot products from heater 1. Veryl heavy material may be so treated, for example, 8 to 10 A. P. I. tar.

It will be observed from a consideration of the foregoing description that while the charging oil or residues may be preheatedif desired to a relatively high temperature, the charge need not be so heated but can be introduced into the cracking still either in a cold state or heated to a moderate temperature not sufficient to cause serious trouble during the raising of the charging stock to that temperature. 'Ihis temperature may not be high enough to cause any considerable amount of purely thermal cracking but may be suillcient to bring about conversion on introduction of the catalytic agent. The process is therefore especially well adapted for the treatment of very heavy oils which may be heated to a temperature less than a cracking value-or introduced while cold directly into the cracking still for treatment. Another method of opera-- tion consists in heating the oil to a cracking temperature in heater 1 without allowing sufcient time to produce any appreciable conversion thereof and introducing this heated oil into the cracking still for soaking or digestion, the desired cracking temperature being maintained by the addition of heat thereto through the introduction of the hot catalyst carrying vapors.

According to another feature of the invention the gas or vapor introduced into the gas heater l may be of a reactive character and be subjected to a decomposing temperature in the heater, the catalyst being introduced into the gas either before or after the heating thereof. In this case the gas itself would be in a state of conversion at the time of its direct contacting with the oil being treated by introduction into the cracking still l.

While I have described a particular embodiment of my invention for the purposes of illustration it should be understood that various modifications and adaptations thereof which will occur to one skilled in the art may be made within the spirit of the invention as set forth in the appended claims.

We claim which comprises passing hydrocarbon oil through a ilrst heating zone wherein it is raised to a cracking temperature, mixing a metallic halide catalyst with the resulting heated oil and intro'- ducing the resulting mixture into a low point in a cracking zone wherein vapors from the oil pass upwardly, removing` the resulting vapors from said cracking zone and fractionating them mediate condensate and l. The method of treating hydrocarbon oil to form a final desired light distillate, an inter- I a heavier condensate, said heaviercondensate through a second heating vzone wherein it is raised to an elevated temperature lower than that attained by the oil in passage through said first heating zone, introducing the resulting heated heavy condensateinto said cracking zone, and combining said intermediate condensate with said oil passing through said first heating zone.

2. A process in accordance with claim l wherein said heavier condensate is of a gas oil nature and wherein said' intermediate condensate comprises heavy naphtha.

3. The process of treating hydrocarbon oil which comprises passing hydrocarbons through a ilrst heating zone wherein they ar'e raised to a temperature suicient to cause the cracking of relatively heavy hydrocarbon oil, vmixing with the resulting heated vapors or gases a quantity of metallic halide catalyst, introducing ythe resulting mixtureinto an equalizing zone wherein the entire mixture assumes a uniform temperature and homogeneous phase, introducingthe Passing resulting uniform mixture of highly heated gases 25 or vapors and vcatalysts into a low point .in a cracking zone wherein the vapors or gases passupwardly, introducing at a higher point in said cracking zone a spray of heavy oil, countercurrent to the rising gases or vapors, whereby said heavy oil is raised to a cracking temperature 'and subjected to conversion, removing resulting gasesor vapors from said cracking zone, cooling kthe mixture to separate a portion of the catalytic material therefrom, fractionating the remaining vapors to form a iinal desired light distillate, and a condensate, and passing said condensate through said first heating zone as a source of said highly heated vapors or gases. A

4. A process in accordance with clairn 3 wherein during the fractionation of the vapors removed from the cracking zone a heavy condensate is formed and said heavy condensate is introduced into said cracking zone with said heavy oil. v

PIKE H. SULLIVAN.' HAROLD V. ATWELL.

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