US1820371A - Process of producing gasoline from high boiling hydrocarbon oils - Google Patents

Description

Aug. 25, 1931. .1. c. BLACK ET Al. 1,820,371

PROCESS OF PRODUCING GASOLINE FROM HIGH BOILING H YDRCCARBON OILS Filed OCL. 5l, 1927 afable/Aux; 52H i O THA/K A 655m /fvf cofvPRfsso/e 55 J fan/Mci mi a v 23 l Hm FACH/M5529 8 cRHcK//v Z 3 4 s ro c/ ATTORNEY Patented Aug. 2.5, 1931 UNITED STATES PATENT ,OFFICE JOHN C. BLACK, OF LOS ANGELES, AND IABVIN L. CHAPPELL, OF WATSON, CALIFORNIA PROCESS OF '.PRODUCING GASOLINE FROM HIGH BOILING HYDROCARBON OILS Application led October 3l, 1927. Serial No. 230,114.

This invention relates to a process for the manufacture of gasoline or motor fuel .b cracking a regulated mixed stream of hlg boiling petroleum oil and hydrogenated oil,

5 hydrogenatmg the products of the cracking reaction, separating the gaseous products and gasoline stock from the higher boiling Petroleum oil, separating the gasoline stock from the gaseous products, decomposing the gascous products into hydrogen and carbon, utilizing the hydrogen for hydrogenating the products of the .cracking reaction, and returning a high boiling hydrogenated distillate to be again cracked.

We are aware that processes are new wellknown for cracking and hydrogenating petroleum oils but such processes have not yet proven a complete commercial success on account of the slowness of the hydrogenating reaction and the high pressures involved.

We have discovered, however, that a li uid hydrogenating agent may be employe in conjunction with hydrogen gas, thereby producing a suiiicient hydrogenation of the higher boiling cracked hydrocarbons, so that the same-may be recracked for the production of gasoline stock without carbon deposition,

and that the same pressure may be employed for the hydrogenating reaction as well as for ao the cracking operation.

Our process, 1n general, consists in contin' uously passing a petroleum oil stock under a pump pressure of more than 500 pounds gauge,.through a series of heatin ranged so that the oil is first preleated by passing through upper rows of heating coils, andthen downward through the lowest row of the heating coil situated in the hottest part of the furnace where the oil is heated to a cracking temperature. From the lower row of the coil the eilv at a cracking temperature passes upward through rows of coils situated in the middle of the furnace maintained at a temperature of approximately 850 degrees F.

In the last coil a sufficient quantity of fresh oil mixed with the hydrogenated oil, approximately 10 to 20 per cent by volume, is introduced into the oil stream to lower the temperature to approximately 700 to 750 degrees F.,

:1nd to effect a partial hydrogenation orhydrobe expressed by the following equation:

etc.l As oil leaves the last coil commingled with the introduced -oil at a temperature of approximately 700 to 7 50 degrees F., a stream of hydrogen gas ranging from 10 to 50 per cent by volume of the oil stream at the temperatures and pressure involved, is introduced into the oil stream. The oil stream, commingled with hydrogen gas ata pressure of approximately 1000`pounds gauge and at the hydrogenating temperature ranging from 700 to 7 50 degrees coil in a second container, wherein a further hydrogenation of the unsaturated hydrocarbons is effected. The higher boiling hydrocarbons are' separated from the gasoline stock and again cracked in conjunction with fresh oil with a further production of gasoline stock from the hydrogenated high boiling petroleum oil stock as well as from the introduced oil.

F. passes through a series of The hydrogenation reaction which takes placey in the second coil is exothermic. l

Therefore, means is provided whereby cool air is passed upward in counterflow to the hydrogenating oil in sufficient amounts to take away the excess heat of the hydrogenation reaction.l

The hydrogen gas employed for hydrogenating the high boiling unsaturated hydrocarbons may be from any source well-known in the art, such for example, as the hydrogen l 'produced by the electrolysis of water, the

`thermo decomposition of hydrocarbon oilsor gases, or by the decomposition of steam in the manufacture of water gas. We prefer, however to obtain 'the hydrogen employed in this process by the thermo decomposition of the hydrocarbon gases produced during the cracking operation, which is accomplished by passing thesepurified gases through an electric furnace or an intermittent blast coke furnace.

Also, it is to be understood that wemay employ the residual oilfrom the distilling` operation as a source of hydrogen in conjunction with the hydrocarbon gases from the cracking operation, in which case a thermo decomposition of the residual oil and gases would be effected either by'a high temperature electric furnace or an intermittent coke blast furnace.

With the foregoing preliminary explanation, the preferred embodiment of our invention Will now be more fully explained by reference to the accompanying drawing which is a diagrammatical representation of an apparatus in which the invention may be carried out. j

AIn the drawing,1 represents generally a tank for the cracking stock. A pipe 2, controlled by a valve 3, connects the tank 1 to the suction side of a pump 4. A pipe 5, controlled by the'valves 6 and 8, connects the discharge side of pump 4 to heat exchanger 9. A pipe 7, controlled by the valves 17 and18, connects the pipe 5 to the pipe 14. A branch pipe 16, controlled by the said valve 18, Yconnects the pipe 7 to a heating coil in the cracking furnace 13. A pipe 6 connects the heat exchanger 9 at the top to the heating coils in cracking furnace 12. The heating coils 10 in the cracking furnace 12 and 13 are connected by a pipe to the heating coils l1 situated in the lower portion of the cracking furnace 12 and 13. The coils in the furnace. 12 and 13 are arranged so that the oil to be cracked enters and passes through the top two rows of coils 10 and then passes downward to the lowest row of c'ls 11 and then passes upward inv concurrent fiow to the furnace ofcompressor 58 to the inlet of hydrogenat,

gases. Said cracking furnace is provided with burners 7 O'with supply pipes leading to a source of fuel not shown. A pipe 14 connects the outlet coil from the cracking furnace 13 to a pipe 19. The pipe 19 controlled by valves 60 and 61 connects the discharge side ing coil20. The hydrogenating coil is interposed in a brick work 21 provided with an air inlet at the bottom 22, so that during the operation air maybe introduced in the necessary amounts t0 take away the exo' .thermic heat of the hydrogenating reaction,

passing over the coils in a generally countercurrent flow to the oil stream.

A- pipe 23 connects the heat exchanger 9 to the outlet of hydrogenating coil 20. A pipe 24 controlled by a pressure regulating valve 25, connects the outlet .side of the heat exchanger 9 to fractionating tower 27. The .fractionating tower 27 is divided into two compartments by the partition 71,' thev lower portion of the fractionating tower being designated by the numeral 26. The partition 71 is provided with an outlet 72 so that the luncondensed vapors may pass upward and through thefractionating device. A pipe 31,

controlled by the valve 32, connects the lower portion of the top section of the fractionating tower 27 to cracking stock tank 1.- A pipe 28,

34 to a separator tower 61. This separator tower 61 is similar to the ractionating tower 27 and is in like manner divided into tWo compartments, and is employed for the separation of the gasoline from the gaseous products produced in the operation. A pipe 37, controlled by the valve 38, connects the bottom of the separator 61 to gasoline tank 36. A pipe 40, controlled by a valve 41, connects the separator 61 at the top to a hydrogen sulphide extractor 42. A pipe 43, controlled by a valve 44, connects the hydrogen sulphide extractor 42 at the top to hydrogen generator 51. A caustic soda tank is connected to the;

hydrogen sulphide extractor 42 by a pipe 74 near the top, so arranged that caustic soda solution may be introduced into the hydrogen sulphide extractor in the form of a spray so as to extract -any hydrogen sulphide or mercapans from the gases which may be generated in the operation. A pipe 46, controlled by a Valve 45, connects the hydrogen sulphide extractor, at the bottom, to a pump 47. A

pipe 48, controlled by a valve 49, connects the.

discharge side of pump 47 to the caustic soda tank 50 at the top. A pipe 52 connects the hydrogen generator 51 to a carbon separator 53. A pipe 54, controlled bya valve 55, is

4connected to the bottom of the carbon sepa;

rator 53. A pipe 56, controlled by the valve 57, is connected to the pump 58 on the inlet side. A pipe 59, controlled by the Valves 60 and 61, connects` the compressor 58 to the pipe 19, by means of which the hydrogen 'produced in the hydrogen generator is introduced into the hydrogenating coil along with the products l'from the cracking reaction and the introduced oil. The preferred process as carried out with the apparatus just described is as follows:

The cracking stock contained in tank 1, which may be any suitable petroleum oil distillate, residuum, or crude oil, is conducted under a pump pressure of approximately -ing stock, in the desired amounts, will be conducted throughv the cracking coils in the furnace 12 and 13. The oil stream iirst passes Y through the heat exchanger 9 where it is heated to a temperature of approximately 4750 F. by a transfer of heat from the outgoing cracked and hydrogenated oil. The oil stream from the heat exchanger 9 first passes through the top two rows of coils in the cracking furnace 12 and 13, and then downward through the last row of coils in the' furnace. From the last row, or hottest coils in the furnace, the oil passes upward through the remaining rows of coils in which a. cracking temperature of approximately 850 to 860 defrees F. is maintained. the oil passes through the last coil it is commingled with a supply of cool fresh oil from the cracking stock tank 1, in quantities suicient to reduce the temperature to a hydrogenating tempera ture, which we have found to be approximately 700 to 750 degrees F. As the oil passes through the last coil, commingled with the fresh oil at a temperature of approximately 700 to 750 degrees F., hydrogenation commences and continues throughout the passage through that coil and into the next set of coils. This hydrogenation, or which may also be called a hydrogen transfer, we believe may be expressed by the following equation which is given as an example only:

CnHemz l- CnHan-g QCnHzn As the oil passes into the pipe 19 it meets a How of hydrogen gas coming from the com-l pressor 58 passing throughthe pipe 59 controlled by the valves and 61. The amount of hydrogen gas introduced depends upon the stock treated and the hydrogenation desired. As a rule, we find that the quantity of hydrogen may be varied from as low as 10 per cent to as high as 50 per cent by volume of the oil flowing through the pipe 19 at the prevailing temperaure and pressure of hydrogen gas. The cracked oil commingled with the introduced fresh ,oil and hydrogen gas passes through the hydrogenating coil in countercurrent flow to air which is introduced into the lower part of the compartment. The quantity of introduced air is varied so as to maintain a hydrogenating temperature ranging from 7 00 to 750 degrees F., the evolved heat of the hydrogenating reaction being absorbed by the air flow around the outside of the hydrogenating coil. It is an important feature of this invention to maintain a close regulated temperature during the passage of the oil and hydrogen through the hydrogenating coil, which 1s necessary to vary in accordance with the products under treatment. The hydrogenated oil, uncombined hydrogen and hydrocarbon gases 4pass through the heat exchanger 9 whereby a heat exchange is effected to preliminarily heat the ingoing oil to be cracked. The hydrogenated products from the hydrogenating coil pass through the pipe 24 and then into the .bottom section of the fractionating tower 26,

where the ressure is reduced to approximate- 1y atmosp eric. The products of the cracking and hydrogenation reaction, upon entering the lower compartment of the fractionating tower 26 separate into a higher and lower boiling fraction, the lower boiling fraction and ases passing upward through the passage 2 and then through the fractionating device, which may be bubble caps or other well-known fractionating devices. In the compartment 26 of the fractionating tower a heavy residual fraction separates which is conducted to the residual storage tank 30\ passing through the pipe 28 controlled by the valve 29. This heavy residual oil separated is suitable for fuel oil, or may be employed for the production of hydrogen gas as heretofore stated. The higher boiling fractions and,- gaseous products which pass into the com partment 27 of the fractionating tower are separated by the fractionation into two portions, the higher boiling portion is conducted back to the cracking stock tank 1, this por?, tion being a hydrogenated oil and is utilized asa cracking stock. The gasoline boiling point stock and gaseous products* separated from the higher boiling fractions, pass through the condenser 34 where most of the gasoline stock is condensed to a liquid and passes into the lower compartment of separator 61, from whence the condensed gasoline is conducted to the gasoline storage tank` 36, passing through the` pipe 37 controlledby thek valve 38. The gaseous products pass from the lower compartment of separator 61 up through a fractionating device, such as bubble caps as 'shown in the upper section of the said separator 61, whereby substantially all of the gasoline boiling point fractions are separated and dropped back into the lower compartment and are conducted to the gasoline storage tank 36 as heretofore explained.

The gaseous products substantially separated from the gasoline fractions pass from the separator 61 through the pipe 40 and into the hydrogen sulphide extractor 42. During the passage of these gases through the'hydrogen sul hide' extractor, substantially all of the hy rogen sulphide and mercaptans are separated by contact with a spray of caustic soda solution, well-known in the art for separating hydrogen sulphide and mercaptans from hydrocarbon gases. The hydrocarbon gases and any unused hydrogen-.substantially free LIl of all impurities pass through hydrogen generator 51, which may be of any preferred type, well-known in the art for decomposing hydrocarbon gases into hydrogen and carbon. From the hydrogen generator 51 the hydrogen gas containing finely divided carbon passes through the carbon separator 53, which may be of any preferred type of form wellknown in the art for the separation of solid particles from the gas, such as a cyclone separator or an electrical separator. Tlie'separated carbon is drawn 0H from the separator 53 by the operation of the valve 55 which per.

mits the carbon to pass out of the system.'

From the carbon separator 53 the substantially pure hydrogen gas passes into the suction side of the compressor 58. The compressor 58 compresses the hydrogen gas so that the same may be introduced into the hydrogenating system at the required pressure, the hydrogen gas passing through the pipe 59 into the hydrogenating coil 20, controlled by the valves boiling hydrocarbons.

As a result of the process of the present invention, petroleum oils may be processed by a cracking operation followed by a. hydrogenation of the cracked hydrocarbons, thus rendering the hydrogenated higher boiling hydrocarbons re-crackable for the further production of gasoline without troublesome carbon depositions.

The most important featurel of this invention is that the major portion of a high ,boiling fraction from av cracking operation may be repeatedly hydrogenated and recracked until substantially all of the fractions have been converted into gasoline. However, it is to be understood that small portion of the gasoline produced by the cracking operation may also be hydrogenated. However, we find that the higher boiling unsaturated hydrocarbons can be hydrogenated at a lower temperature andpressure than the lower boiling unsaturated hydrocarbons.

While the process herein described is well adapted for carrying out the objects of the present invention, it is understood that various modifications may be made without departing from the spirit of the invention and the invention includes all such modiications and changes as come within the scope of the appended claims.

What we claim is:

1. A process of converting high boilin hydrocarbons into lower boiling hydrocar ons, comprising cracking a hydrocarbon oil at a temperature of approximately 850 to 860 degrees F., introducing into the cracked products a cooler uncracked hydrocarbon oil, in quantitiessucient to lower the temperature of the mixed oils to a temperature of approxii mately 700 to 750 degrees F., commingling the mixed oils with hydrogen gas, maintain.- ing the commingled mixed oil and hydrogen gas at atemperature of approximately 700 to 750 degrees F., for a period of time suiiicient to hydrogenate the maj or portion of the unsaturated hydrocarbons contained therein, separating the higher boiling hydrocarbons from gasoline boiling point hydrocarbons,

and returning the separated higher boiling hydrocarbons to the system to be re-cracked.

rated hydrocarbons produced by the cracking reaction, separating the gasoline stock from higher boiling hydrogenated hydrocarbons and then re-cracking the hydrogenated highv boiling hydrocarbons.

3. A process of converting high boiling hydrocarbons into lower boiling hydrocarbons, comprising cracking a hydrocarbon oil at a temperature of approximately 850 to 860 degrees F. under a super-atmospheric pressure, introducing an uncracked hydrocarbon oil and hydrogen gas into the products produced by the cracking reaction and maintaining the mixture at a temperature of approximately 700 to 750 degrees F. for a time suicient to substantially hydrogenate the unsaturated hydrocarbons contained therein, separating a high boiling hydrogenated distillate from the gasoline boiling point stock, gaseous products and a residuum and re-cracking the said hydrogenated distillate along with a portion of uncracked oil.

4. A process of producing gasoline boiling point stock from higher boiling hydrocarbon oils, comprising cracking a hydrocarbon oil at a temperature of approximately 850 to 860' degrees F. under a super-atmospheric pressure of approximately 1000 pounds, injecting a mixture of a cooler uncracked oil and a hydrogenated oil into the mixture obtained, in quantities suttcient to lower the temperature of the mixed oils to approximately `700 to 7 50 degrees F., then introducing hydrogen gas in quantities sufficient to hydrogenate substantially all of the higher boiling unsaturated hydrocarbons, maintaining said temperature and pressure until the hydrogenation reaction is substantially complete, and separating and re-cracking the higher boiling hydrogenated hydrocarbons.

5. A process of cracking and Ahydrogenating hydrocarbon oils for the production of gasoline stock, comprising heating oil to a temperature of approximately 850 to 860 degrees F .under super-atmospheric pressure, introducing an unheated by-passed portion of the mainstream of oil into the oil undergoing heating, in quantities suflicient to lower the temperature of the mixed oil stream to a temperature of approximately 700 to 750 degrees F., then introducing hydrogen gas and maintaining a constant temperature of approximately 700 to 7 50 degrees F. and a pressure of approximately 1000 pounds until sub- `v stantially all of the higher boiling unsaturated hydrocarbons have been hydrogenated,

and then separating and re-cracking the hydrogenated higher boiling hydrocarbons to produce lower boiling hydrocarbons.

6. A process of cracking and hydrogenating hydrocarbon oils for the production of gasoline boiling point stock, comprising heatlng a lhydrocarbon oil ina confined stream under super-atmospheric pressure to a temperature of approximately 850 to 860 Y degrees F., introducing into the final pass of approximately 850 to 860 degrees and exit from the heating coil, cooler oil in quantities sufficient to lower the temperature of the mixed Y oil stream below the active cracking reaction temperature, substantially approximately 700 to 750 vdegrees F., and then introducing hydrogen gas and maintaining a temperature of approximately 7 00 to 750 degrees F. at a pressure of approximately 1000 pounds until substantially all of the cracked hydrocarbonoils have been hydrogenated and then re-cracking the hy-` drogenated higher boiling oils separated from the lower boiling oils.

7. A process of converting high boiling4 hydrocarbons into lower boiling hydrocarbons, comprising heating a hydrocarbon oil in va confined stream under super-atmospheric pressure at a cracking temperature F., introducing into said stream a cooler oil from the same source in quantities suiicient to,

reduce the temperature to approximately 700 to 750 degrees F., then introducing hydrogen gas in vquantities suiiicient to hydrogenate substantially all of the unsaturated hydrocarbons contained therein, maintaining the commingled oils and hydrogen gas at sa1d hydrogenating temperature and pressure until the hydrogenation reaction is s ubously injecting into the oil stream after the mixed oil to a temperature of approximately 700 to 750 degrees F., continuously introducing hydrogen gas into the mixed oil stream and maintaining a temperature of approximately 700 to 7 Odegrees F. and a pressure of approximately 1000 pounds on the mixed oil stream commingled with the hydrogen gas. l

9. A -process of converting high boiling hydrocarbons into lower boiling hydrocarbons, comprising continuously cracking a hydrocarbon oil under a pressure of approximately 1000 pounds at a temperature of approximately 800 to 860 degrees F., continuousl injecting into the oil stream after the crac ing reaction, a cooler uncracked h drocarbon oil, in quantities suflicient to ower the temperature of the mixed oils to a temperature of approximately 7 00 to 750 degrees F., continuously introducing hydrogen gas into the mixed oil stream, and maintaining ay temperature of approximately `700 to 750 degreesF. and a pressure of approximately 1000 pounds on the mixed oil stream commingled with the h drogen gas, separating a higher boiling hy rogenated fraction from the products of hydrogenation and returning the fraction to the system to be recracked.

10. A rocess of converting high boiling hydrocar ons into lower boiling hydrocarbons, comprising cracking a hydrocarbon oil at temperatures ranging from approximately 850 to 860 degrees F., immediately reducing the temperature after the cracking reaction is substantially complete, to 700 to 750 degrees F. and introducing hydrogen gas, maintaining the products of the cracking reactioncommingled with hydrogen gas under a pressure of approximately 1000 pounds and at the said temperature of approximately 700 to 750 degrees F., said temperature being maintained by extracting the exothermic heat of the hydrogenating reaction, and maintaining said temperature for a period of time suiicient to -hydrogenate substantially all the unsaturated hydrocarbons cona tained therein. l

11. A process of converting high boiling petroleum oils into lower boiling oils, comprising, cracking a petroleum oil and introducing into the hot cracked oil a cooler uncracked petroleum oil in quantities sufficient 'to lower the temperature of the mixed oils to a hydrogenating temperature, then introducing hydrogen gas, maintaining the mixed oils commingled with the hydrogen gas at a substantially constant hydrogenating temperature and pressure by continuously extracting the exothermic heat produced by the hydrogenating reaction with a flowing cooling fluid, for a period of time sutlicient to substantially hydrogenate all unsaturated hydrocarbons contained by the oils.

12. A process of converting high boiling petroleum oils into lower boiling oils, comprising, cracking a petroleum oil at a cracking temperature under superatmospheric.

pressure greater than 500 pounds gauge, introducing into the hot cracked oil a cooler uncracked petroleum oil and hydrogen gas in quantities sufficient to lower the temperature of the combined mixed oils and hydrogen gas to a hydrogenatin temperature of approximately 7 00 taining the mixed oils and hydrogen gas at to 750 egrees F., main-- the said hydrogenating temperature and pressure by continuously extracting the exothermic heat produced by the hydrogenating reaction with a flowing cooling fluid, for a period of time suiicient to substantially hydrogenate all unsaturated hydrocarbons con-v tained in the mixed oils.

13. A process of converting high boiling petroleum oils into lower boiling oils, comprising, cracking a petroleum oil and introducing into the hot cracked oil a cooler uncracked petroleum oil in quantities sufficient to lower the temperature of the mixed oils to a hydrogenating temperature, then introducing hydrogen gas, maintaining the mixed oils commingled with the hydrogen gas at a substantially constant hydrogenating temperature and pressure by continuously extracting the exothermic heat produced by the hydrogenating reaction with a flowing cooling fluid, for a period of time sufficient to substantially hydrogenate all unsaturated hydrocarbons contained by the oils, then separating a higher boiling hydrogenated fraction from the mixed oils and gaseous products and returning the same to the system to be recracked.

14. A process of converting high boiling -petroleum oils into lower boiling oils, com-4 prising, cracking a petroleum oil and introducing into the hot cracked oil a cooler uncracked petroleum oil in quantities suiiicient to lower the temperature of the mixed oils to a hydrogenating temperature, then introducing hydrogen gas, maintaining the mixed oils coniiningled with the hydrogen gas at a substantially constant hydrogenating temperature and pressure by continuously extracting the exothermic heat produced by the hydrogenating react-ion with a flowing cooling fluid, for a period of time sufficient to substantially hydrogenate all unsaturated hydrocarbons contained by the oils, then separately separating by fractionation a higher boiling hydrogenated distillate, a lower boiling distillate, gaseous products and a residuum from the mixed oils and gaseous products, and returning the higher boiling hydrogenated distillate to the system to be recracked.

15. A process of converting high boiling petroleum oils into lower boiling oils, comprising, cracking a petroleum oil at a cracking temperature under superatmospheric pressure greater than500 pounds gauge, introducing into the hot cracked oil a cooler uncracked petroleum oil and hydrogen gas in quantities suiicient to lower the temperature of the combined mixed oils and hydrogen gas to a hydrogenating temperature of approximately 700 to 750 degrees F., maintaining the mixed oils and hydrogen gas at the said hydrogenating temperature and pressure by continuously extracting the exotliermic heat produced by the hydrogenating reaction with a flowing cooling fluid, for a period of time suficientto substantially hydrogenate all unsaturated hydrocarbons contained in the mixed oils, then separating a higher boiling hydrogenated fraction from the mixed oils and gaseous products and returning the same to the system to be recracked.

16. A process of converting high boiling petroleum oils into lower boiling oils, comprising, cracking a petroleum oil at a cracking temperature under superatmosphericpressure greater than 500 pounds gauge, introducing into the hot cracked oil a cooler uncracked petroleum oil and hydrogen gas in quantities suflicient to lower the temperature of the combined mixed oils and hydrogen gas to a hydrogenatin temperature of approximately 700 to 7 50 egrees F., maintaining the mixed oils and hydrogen gas at the said hydrogenating temperature and pressure by continuously extracting the exothermic heatproducedby the hydrogenating reaction with a flowing cooling fluid, for a period of time suiiicient to substantially hydrogenate all unsaturated hydrocarbons contained in the mixed oils, then separately separating by fractionation ahigher boiling hydrogenated distillate, a lower boiling distillate, gaseous products and a residuum from the mixed oils and gaseous products, and returning the higher boiling hydrogenated distillate to the system to be recracked.

17. The step in the process of hydrogenating petroleum oil containing unsaturated hydrocarbons, comprising, passing the petroleum oil and hydrogen gas under superatmospheric pressure of more than 500 pounds gauge, at a hydrogenating temperature of approximately 700 to 750 degrees F., through an elongated-passageway, and maintaining said hydrogenating temperature by continuously extracting the exothermic heat as produced by the hydrogenation reaction with a flowing cooling fluid.

18. The step in the process of hydrogenating petroleum oil containing unsaturated hydrocarbons, comprising, passing the petroleum oil and hydrogen gas under superatmospheric pressure of more than 500 pounds gauge, at a hydrogenating temperature of approximatelylOO yto 750 degrees F., through an elongated passageway, and maintaining said hydrogenating temperature by continuously extracting the exothermic heat as produced by the hydrogenation reaction with a flowing cooling fluid flowing countercurrent to the flow of petroleum oil and hydrogen gas.

19. The step in the process of hydrogenating petroleum oil containing unsaturated hydrocarbons, comprising, passing the petroleum oil and hydrogen gas under a pressure of approximately 1000 pounds gauge, at a temperature of approximately 700 to 750 degrees F., through a pipe coil and maintaining said hydrogenating temperature by continuously extracting the exothermic heat produced by the hydrogenating reaction with a cooling fluid.

20. The step in the process of hydrogenat-y ingipetroleum oil containing unsaturated hydrocarbons, comprising, passing the petrolef um oil and hydrogen gas under a pressure of approximately 1000 pounds gauge, at a temperature of approximately 700 to 750 degrees F., through a pipe coil, and maintaining said hydrogenating temperature by continuously extracting the exothermic heat produced by the hydrogenating reaction with a cooling fluid flowing countercurrent to the flow of petroleum oil and hydrogen gas.

21. The step in the process of hydrogenating petroleum oil, containing unsaturated hydrocarbons produced by cracking petroleum oil, comprising, passing the cracked petroleum oil, hydrogen gas and an uncracked petroleum oil under a pressure of more than 500 pounds gauge, at a hydrogenating temperature of approximately 7 00 to 750 degrees F., through a pipe coil, and maintaining said hydrogenating temperature by continuously extracting the exothermic heat as produced by the hydrogenation reaction with a flowing cooling fluid.

22. The step in the process of converting high boiling petroleum oil into lower boiling hydrocarbons, comprising, introducing into a hot cracked petroleum oil as it leaves a liquid phase cracking system, at an elevated cracking temperature under superatmosplieric pressure of more than 500 pounds gauge, a cooler uncracked petroleum oil in quantities suiicient to lower the temperature of the mixed' oils to approximately 7 00 to 750 degrees F., commingling the mixed oils with hydrogen gas, maintaining the mixed oils, and hydrogen gas at a temperature of approximately 7 00 to 750 degrees F. by continuously extracting the eXothermic heat as produced by the hydrogenation reaction with a flowing cooling fluid, for a period of time suiiicient to hydrogenate the major portion of the unsaturated hydrocarbons contained therein, separating a higher boiling distillate from gasoline boiling point oils, gaseous products and a residual oil, and recracking the separated higher boiling distillate.

In testimony whereof we aflix our signatures. l

JOHN C. BLACK. MARVIN L. CHAPPELL.

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