US1871431A - Process of treating hydrocarbons - Google Patents

Description

Aug. 9, 1932. w M. CROSS- PROCESS OF TREATING HYDROCARBONS Filed 00L 6, 1924 s Sheets-Sheet 1 INVENTOR [fa/7% 0'03; 744/ @@@Q 0 o 0 13m a M o o o ATTO EY.

Aug. Q, 1932. w. M. CROSS PROCESS OF TREATING HYDROOARBONS 3 Sheets-Sheet 3 Filed Oct.

ATTO EY.

Patented Aug. 9, 1932 WALTER M. CROSS, OF KANSAS CITY, MISSOURI, ASSIGNGR, BY MESHE ASSIGTS,

TO GASOLINE PRODUCTS COMPANY, INC., OF WILMINGTON, DELAWARE, A CORPO- RATION or DELAWARE PROCESS OF TBEATHJ'G H'YDRGGARBQNS Application filed October 6, 1324:. Serial No. $11,318.

This invention relates to improvements in a process of treating hydrocarbons, and refers more particularly toa process usedfor converting-relatively heavy hydrocarbons into lighter hydrocarbons preferably of a gasoline-like nature.

This application is a continuation in part of aprevious application Serial No. 503,335, filed September 26, 1921, which was in turn a true divisional of an original or parent ap. plication Serial No. 128,839, filed November In the process of this invention the hydrocarbons are treated in a continuous process as distinguished from an intermittent process, thereby not only permitting a fresh supply of hydrocarbon oil to be continuously fed to the apparatus, but also resulting in getting more uniform and better results.

In addition to charging an oil to be treated continuously, the converted product was drawn ofi continuously and directed to a stage of reduced pressure where the treated material was distilled with the contained heat of the oil due to the pressure reduction which took place between the conyersion stage and the distillation stage.

Among the advantages of the invention are much increased economy of operation, not only in fuel consumption, but also in the quantity of oil that can be treated at a given time. A further advantage is that inasmuch as in the continuous process, the temperature can be maintained substantially constant for relatively long periods of time instead of alternately heating and coolingthe apparatus as is necessaryv in intermittently operated processes, and the life of the apparatus. will be correspondingly prolonged as there will be much less strain on the still. Other advantages of the invention will appear to those tube arrangement on an enlarged scale.

Fig. 3 is a plan View, partly diagrammatic and partly in section, of my improved apparatus.

Fig. i is a transverse sectional view taken on lines 1- 1 of Fig. 3 but on an enlarged scale. f

Referring to Figs. 1 and 2, 1 designates a furnace having the usual fire box'2, above which is located a series of tubes 3, opening at their opposite ends "into hollow plates 4 and 5. A plurality of bafiie plates 6 and 7 are employed in the furnaces for. forcing the hot gases along substantially the entire length of thetubes 3 before passing to the stack 8. Opening into the lower portion is an inlet 9 connected to a source of supply in the manner hereinafter described, and at the upper end of the end plate is an outlet 10 connected by a conduit 11 with converter tank 12. Leading from this convertor tank is a pair of discharge pipes 13 and 14:, the latter ofwhich connects with a reheater 15, and the former is connected with the inlet pipe 9. Referring to Figs. 3, 18, 18a, 1822, 180, 18d and 186 represent circulating pumps. 19, 19a, 19?), etc., represent the motors to drive the same. 13, 13a, 13?), etc., and 11, 11a,,11b, etc., represent the circulation pipes. Disposed at right;

angles to the longitudinal axis of the chamf' ber 12 are a plurality of bafiie plates 34a, 34b,

340, 34d, 34c; 33 is a main supply pump, and 36 a motor to drive the same, 37 the intake pump 33 and emptying into the chamber 12.

In the employment of this apparatus, it

is contemplated that the substance .treated will circulate from the convertor tank 12 freely through the furnace tubes 3 (Fig. 2) of the heating furnaces 1, 1a, 112, etc., and

back into'the convertor tank 12. In order to said pump and 35 is a feed pipe extending from the in a continuous passage, that is, oil introduced at one end of the convertor tank will be circulated through the heating coil in the furnace 1, thence back into the convertor through the discharge line 11 and into the next succeeding coil positioned in the furnace 1a; through the line 13a, and back to the convertor through the line 11a. The oil circulated in this manner travels continuously from the charging line to the discharge line 14. The passage through the various pipes is controlledby suitable valves, a cutoff valve 22 is in position on the pi e 14 for controlling the passage of treate oil from the convertor tank 12 to the still 15. Also the pipe 31 is provided with a cutoff valve 32 for controlling the flow of vapor from the convertor 12 direct to the condenser 29. A p1pe 28 leading from the still 15 to the condenser 29 is provided with a check valve 39. The optlet of the condenser coil 29 is provlded with a valve 40.

In'starting the process, the mtake 37 of the pump 33 is connected with a suitable supply of oil to be treated, Then the pump 33 is started and driven by the motor 36, pumping the oil into the convertor 12 through the intake 35. As soon as suflicient oil is pumped into the apparatus, one third full more or less, the circulating pumps 18, 18a ,18b, etc., are all started and heat is applied in the furnaces 1, 1a, 16, etc. Now the pump 33 1s stopped, and the heat is applled 1n the furnaces 1, 1a, 16, etc., until the pressure 1n the apparatus reaches the point that it 1ncreas es out of proportion to the temperature, that 1s, when such a temperature is reached that pressure begins to rise without any further 1ncrease in temperature, the pressure in this case being that pressure due to the vapors from the hydrocarbons subjected to the treatment being generated by the heat. Now this reacting temperature is maintained for a period of thirty minutes more or less according to the character of the oil used. In any event, the temperature is maintained in the apparatus until a substantial amount of conversion products or gasoline-like products is obtained or formed in the oil itself. After this reacting time has been allowed, the valve 22 is opened andthe pump 33 again started so that the discharge of oil through the pipe 14 together with any discharge of vapor is replaced by the oil that is pumped in through the intake 35 simultaneously. If the pressure becomes excessive, the valve 32 is opened.

and some of the vapors are allowed to pass out through the pipe 31 into the condenser 29 and then discharged. If satisfactory c ondensation and separation of the condensible vapors from non-condensible vapors'is not accomplished in the condenser 29 when it is operated at atmospheric pressure, the valve $0 'on the outlet of the condenser is partially closed so that suflicient pressure is built up in the condenser 29 so as to insure satisfactory separation of condensible from non-condensible vapors in the condenser 29. When suflicient oil has been discharged through the pipe 14 into the still. 15 so asto partially oil, additional heat will be necessary to effect the desired degree of volatilization. Simultaneously, vapor may also be delivered into the condenser 29 through the pipe 31 and valve 32. As previously mentioned, the overhead material withdrawn from vthe conversion stage may consist of both incondensible and condensible material. The length of the convertor chamber 12 and the number of heating furnaces 1, 1a, 1b,. etc., will be determined entirely by the amount of oil that is to be treated in any one 24-hour period. The oil in this process, after it is started, is pumped in at such a rate that it will remain in the apparatus and be subjected to the reacting temperatures thirty minutes more or less ac-. cording to the time requiredfor producing gasoline or gasoline-like bodies. A pressure of from 100 to 800 pounds may be maintained, this varying with conditions.

It is self-evident that the longer the convertor chamber 12 and the more numerous the furnaces 1, 1a. 1?). etc., the more rapidly oil can be pumped in the apparatus and still allow the necessary reactive time for the production of the gasoline-like product. In order that the oil may not circulate by convection backward, bafiie plates 34a, 34b, 34c, 34d, 34c, etc., may be placed in the vapor chamber 12 at right angles to its longitudinal dimensions. A cross section of the convertor chamber 12 with baflie plates 34a, etc., is shown in Fig. 4. The height ofthis baffle plate is ,one-fourth the diameter of the vapor chamber 12. more or less according to the amount of oil that is being carried in the apparatus during the operation.

The operation of this process provides means for continuous operation and recovery pf gasollne and gasoline-like products durmg the operation of the process. It is well known that if a hydrocarbon oil is being subected to a-cracking process or a conversion process, whereby light hydrocarbons are formed that there are also formed methane and other gases, which cannot be condensed into a liquid at atmospheric temperature. The amount of methane and non-condensible retreat gas then is proportioned to-the amount of like product that is condensible into a liquid at atmospheric temperature. In the operation of this process, such pressure is produced that gasoline or gasoline-like bodies may exist inical equilibrium in as great amount as would be the case if the vapor and oil were withdrawn at the same time. Laboratory apparatus, operated in this way, showed conclusively that it during the operation of the process, non-condensible gas was withdrawn, a larger amount of-gas was formed than is the case were it not withdrawn. Also it was demonstrated that if the gasoline were removed from the apparatus while the process was in operation, that a somewhat larger yield was obtained than was the case when-the volatilematerial was removed at the same time. It was necessary, however, to remove some of the volatile material as the pressure rose excessively high if it was not done,rprovided. the gasoline waswithdrawn and new oil pumped in during the operation of the apparatus. 3 I

In my copending application Serial No. 667,380, filed Oct. 8, 1923, I have set forth and claimed certain of the subject matter described herein.

I claim as my invention:

1. An improvement in the art of oil conversion for the purpose of producing lighter from heavier hydrocarbons, which consists in subjecting the oil in a tube and tank to cracking conditions of temperature and a pressure controlled to prevent substantial vaporization of the light hydrocarbons, re-

moving vaporous products of conversion from the oil body undergoing cracking to prevent excessive pressure, withdrawing continuously the unvaporized liquid products and distilling therefrom the lighter fractions by reducing the pressure thereon, condensing and collecting the evolved vapors from the distillation under reduced pressure and the said vaporous products of conversion.

2. An improvement in the art of oil conver-' sion for the purpose of producing lighter from heavier hydrocarbons, which consists in subjecting the oil in a tube and tank to cracking conditions of temperature and pressure,

controlled to prevent substantial vaporiza point in the conversion stage to control the pressure in said stage and the liquid products from alow point, releasing the pressure on the liquid products whereby the lighter fractions will distill ofi,,condensing and collectingcondensible material from the evolved vapors together with the product removed from the high point of the conversion stage.

3. An imprcvementin the art of oil conversion for the purpose of producing lighter from heavier hydrocarbons, which consists in subjecting the oil in a tube and tank to cracking conditions of temperature and pressure, controlled to prevent substantial vaporizationvv ofqthe .light hydrocarbons, removing gaseous products from the oil body undergoing cracking to control the pressure in said oil body, continuously withdrawing the liquid converted material andpassing it to a zone of reduced pressure without cooling whereby the lighter fractions will distill off, simultaneously condensing and collecting the condensible products from the volatile material withdrawn from the cracking stage and prevent any substantial portion from vaporizing at temperatures to which the oil is heated, simultaneouslyand separately withdrawing gaseous and liquid products from the conversion chamber, passing the liquid cooling whereby the lighter fractions will distill off," liquefying by condensation condensible products from the material removed from the cracking stage together with vapors evolved in the zone of reduced pressure.

' 5. An improvement in the art of oil conproduct to .avzone of reduced pressure without version for the purpose of producing lighter from heavier hydrocarbons, which consists in charging oilcontinuously to a tube and enlarged conversion chambenin maintaining and subjecting it to temperature and pressure conditions to induce cracking but prevent any substantial portion from vaporizing at tem peratures to which the oil isv heated, simultaneously and separately withdrawing gaseous and liquid products from the" conversion chamber, passing the liquid product to a zone of reduced pressure without cooling whereby the lighter fractions will distill off, liquefying by condensation condensible products from the volatile material withdrawn from "the-conversion.stage and the vapors evolved products under by distillation'of the liquid reduced pressure conditions.

j 6. An improvement in the art of pressure distillation. for the purpose of: producing lighter from heavier hydrocarbons, which consists in subjecting the oil in a tube and prevent excessive pressure on the oil undergoing conversion in the chamber, continuously passing the heated unvaporized hydrocarbons without cooling to a still and there distilling off the lighter fractions under reduced pressure conditions, condensing such lighter fractions in combination with the lighter fractions removed from the initial zone ofconversion.

7. A process of converting heavy hydro-- carbons into lower boiling point hydrocarbons consisting in passing the oil continuously through a cracking chamber comprising local circulations of relatively small quantities of oil through heating tubes and returning the same to a bulk of supply, maintaining such a pressure on the hydrocarbons as will prevent any substantial portion thereof vaporizing at temperatures to which they are subjected in this cracking chamber, passing regulated quantities of cracked oil in a liquid condition without substantial cooling to a still in which the oil is released to atmospheric pressure, and taking ofi incondensible gases from the cracking chamber to prevent excess rise in pressure.

8. A process Of'CODVGItiIlg heavy hydrocarbons into lower'boiling point hydrocarbons consisting in passing the oil continuously through a cracking chamber comprising local circulations of relatively small quantities of oil from a bulk supply'maintained in a converter not completely filled with oil through heating tubes, returning this heated oil to the converter, and maintaining such a pressure on the hydrocarbons as will prevent any substantial portion thereof vaporizing at temperatures to which they are subjected in this cracking chamber, passing regulated quantities of cracked oil in a liquid'condition without substantial cooling to a still in which the oilis' released to atmospheric pressure, taking off incondensible gases from the cracking chamber to prevent excess rise in pressure, the pressure in the cracking chamber being maintained by the incondensible gases formed and such vapors as are vgenerated.

9. A process of converting heavy hydrocarbons into lower boiling point hydrocar bons, consisting in continuously passing the oil through a heated cracking chamber comprising local circulations of relatively small quantities of oil from a bulk supply maintained in a converter not completely filled with oil through heating tubes, returning this heated oil to the converter, and maintaining such a pressure on the oil as will prevent the major portion thereof from vaporizing at temperatures at which the oil is heated, while passing through said cracking chamber, causing the oil to pass from said cracking chamher without substantial cooling to a still in which the oil is released to substantially atmospheric pressure and taking off incondensible gases from the cracking chamber sufficient to prevent excess rise in pressure.

10. A process of converting heavy hydrocarbons into lower boiling point hydrocarbons, consisting in passing the oil through heating .units, thence combining the heated oil from said units in a converter chamber, and maintaining sue a pressure on the oil as will prevent the ma or portion thereof from vaporizing at temperatures to which the oil is heated, causing local circulation through the heating units from the converter chamber, passing the heated oil without substantial cooling to a still in which the oil is released to substantially atmospheric ressure, and taking off incondensible gases om the converter chamber sufiicient to prevent excess rise in pressure.

11. A process in accordance with claim 7 wherein said heating tubes are subjected to independent sources of heat.

12. A process in accordance with claim 10 wherein said heating units are independent from one another..

13. An improvement in the art of oil conversion for the purpose of producing lighter from heavier hydrocarbon products, which consist in maintaining a considerable body of oil undercracking conditions of temperature and pressure, continuously withdrawing oil from the said body and passing the oil without cooling and without intermingling with 'a higher temperature inert heating medium to a still into which the oil is released at reduced pressure whereby the lighter fractions are vaporized, removing the resulting vaporized lighter fractions, taking ofi condensible and incondensible gases from said body to prevent an excessive rise in pressure and combining said condensible and incondensible gases with vaporized lighter fractions removed from said still and subjecting the combined; gases and vaporized lighter fractions to cooling to effect condensation.

14. An improvement in the art of oil conversion for the purpose of producing lighter from heavier hydrocarbon oil which comprises passing said heavier hydrocarbon oil in a relatively small stream through a heating zone, wherein it-is heated to' cracking temperature, then conducting the oil from said stream after heating to an enlarged body of oil located outside of said heating zone, maintaining cracking conditions of temperature and pressure on said body, continuously withdrawing oil from said body and passing the oil without cooling and without interminglingw-ithahigher temperature inert heating medium to a still into which it is released at l a reduced pressure whereby the lighter fractions are vaporized, removing the resulting vaporized lighter fractions, taking 01f con,- densible and incondensible gases from the cracking stage to prevent excessive rise in pressure and combining said condensible and incondensible gases with vaporized lighter fractions removed from said still, and subjecting the combined gases and vaporized lighter fractions to cooling to effect condensation.

WALTER M. CROSS.

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