US1929529A

US1929529A - Process and apparatus for converting hydrocarbon oils

Info

Publication number: US1929529A
Application number: US293869A
Authority: US
Inventors: Claude W Watson
Original assignee: Texaco Inc
Current assignee: Texaco Inc
Priority date: 1928-07-19
Filing date: 1928-07-19
Publication date: 1933-10-10
Anticipated expiration: 1950-10-10

Description

Oct. 10, 1933.

C. W. WATSON PROCESS AND APPARATUS FOR CONVERTING HYDROCARBON OILS Filed July 19, 1928 Elma/WW a om m mm

Patented Oct. 10, 1933 I 1,929,529 Paoosss AND arm-nuns ron I we arnaoosaaoa one 7 Claude W. Watson, Port Arthur, 'lfexy, assignor to The. Texas Company, New York, N. 1., a corporation of Delaware pplication my 19, 1928. swarm. 29am 12 Claims. (01. 196-49) This invention relates to cracking processes and contemplates the removal, at the proper stage of the treatment or conversion, 01 the carbon and coke and elements tending to i'orm the '8- same when charging a heavy oil of the nature of topped crude oil or fuel oil to a cracking process.

The invention contemplates heating the entire charge or heavy oil to an elevated temperature while under several atmospheres of pressure and 1 separating out the carbon, residue and objectionable heavier compounds from the oil undergoing treatmenhand ridding the system of such components by removing them from a separating zone while delivering an overhead vapor comparal" tively free of carbon and coke to a reaction or vapor conversion zone for further treatment.

While there is illustrated and described a pre-:

ferred embodiment of the invention in which the apparatus is adapted to carry out a liquid phase cracking process it will be understood that the oil undergoing treatment a in vapor form when leaving the separating zone and may therefore be further treated in the vapor phase, as for example in a so called converter.

In the normal operation of the process topped crude or other heavy petroleum fractions may be charged to a heating coil of restricted area wherein a suitable super-atmospheric pressure,

which may be 100 pounds per square inch or more, may be maintained. The said charge preterably may be commingled with a reflux condensate at some intermediary point in the said heating coil and be highly heated in transit therethrough. Upon leaving the heating coil the highly heated oil which may have a temperature of theorder of 850 F., is conducted to the first stage of separation and delivered into an enlarg'ed primary or high pressure chamber upon a hood or other means which may act as a 40 spreader for the entering liquid while acting as an umbrella under which evolved vapor may gather andbe withdrawn. A pressure within the said chamber is preferably maintained substantially equal to that existent in the heating coil and I refer to this part 0! the separating zone as the high pressure stage. The highly heated oil entering is distributed upon a spreader within the top of the said enlarged chamber and flows down upon the outside of the spreader skirt or hood in a film and evolves and separates into a vapor and a liquid fraction. The liquid fraction flowing down and depositing itself with in the bottom oi the chamber is continuouslyand regulatively withdrawn. The hot oil withdrawn from the first stage of separation. is conducted to the second stage at separation and delivered intoa second enlarged chamber of the same general description as the mstdcscribed. 1n the second chamber the pres sure is preferably carried very much lower: than the pressure in the first chamber and I rater to the second chamber as the low pressure stage. At times however-in this stage I maywish to ap proach the pressure carried in the first chamber. The hot liquid entering the said second chamber a evolves and separates into a vapor traction and a liquid fraction. The liquid depositing itself within the bottom .of thc said second chamber may be continuously androgulatively therefrom and discharged from the s. This 1. liquid may ordinarily include carbonyrosiduo and objectionable compounds which tend to vform coke and generally hinder the continuous sue-i cesalui operation of the equipment. As proper fractionation, is often dimcult toaocomplish I My, provide for a certain amount oi agitation of the liquid, either "violent or gentle, in this second chamber. a a

It is obvious that more than two chambers'in' more than'two'stagos'ot separation may be 0511- 3 ployod operatingat desired pressure. In

the particular example or the invention under discussion two chambers m two stages seem sutncient, however I mayomploy more in treating difierentoils. Cy

The vapor evolved in the firstchamber is withdrawn from a sheltered area so as to exclude substantially all oi the liquid particles and the said vapor, being of considerable volume, is'dolivored at high velocity through compression means, whieh'may be of the jet compressor type, and in go thorethrough may pick up or entrain the vapor from the second chamber which is gathered from the second chamber in a sheltered area, so that it too is free from substantially all liquid particles. Both the vapor fraction from the first chamber and from the second chamber in the separating zoneare thereby oommingicd and the relatively clean vaporous admixture is delivered into the reaction zone or eonverter which may 1' also be maintained under superatmospheiio pressure. Naturally the pressure in the reaction zone or converter would be lower than the pressure in the first chamber of the separating zone but ordinarily vory'mueh higher than the pressure in the I second chamber. By relatively clean vapor I" mean a vapcr which when condensed would how come a liquid substantially tree in tree when and coke.

. with this andotherobieots in viewthe iuvcn. m

tion is more fully described in the following specification and defined in the claims.

The features of this invention are illustrated in the accompanying drawing in which an apparatus suitable for carrying on the process is shown in diagrammatic elevation with certain parts in sectional elevation, although it will be understood that any other apparatus of suitable type may be adapted for practicing the said invention.

Referring to the drawing: Heavy oil to undergo treatment may be passed in heat exchange through closed coil l in; reflux exchanger 64 and entering the system through pipe 2 may be passed through an economizer bank 15 or section 3 and forced into the heating coil or preheater 4 of suitable designto withstand high pressure and temperature. There is provided a line 5 for the introduction of reflux condensate into lower-portion of the heating coil 4.

The highly heated oil upon emerging from the heating coild is conducted through pipe 10 pro: videdqwith drain line 11 to the enlarged heat insulated chamber 15.

.The'highly heated oil emerges irompipe 10 through asuitable distributing nozzle 12 situated near'the top and within the chamber 15, and is delivered-upon spreading means 13, being preferably constructed conically and having a vertical skirt 14. Such fraction of theoil as, remains in liquid 30; form deposits itself in the bottom of the cham-1 ber 15 and is regulatively withdrawn therefrom by means of thepipe l6 and the interposed valve 17, which may be controlled by the rise and fall of the fioat 18,-buoyed up bythelevel of liquid within -;the ohamber; 15;. Ordinarily Imay carry a high pressure in'the chamber .l5. q

The hot oil emerging from pipe '16 is conducted through the distributing nozzle situated within the top of the heat insulated chamber 20 and is 9 delivered uponspreading means 26,;-being;preferably constructed conically and having a verticalskirt 27. Ordinarily I maycarry a much lower pressure in the chamber 20 than in the chamber 15. 1

Such fraction of; the oil asremains liquid in chamber 20 depositsitself withinthe bottom of the said chamber andisregulatively withdrawn from the system by means of thepipe- 21- andthe interposed valve 22, which may be controlled by- 5 l the rise and fall of the float 23 buoyed up by the level of liquid within the chamber 20.

Suitable stirring or agitating means 24 is provided within the bottom of chamber '20, driven at anydesired speed by means not shown. 55.: That fraction of the highly heated oil vaporized in the chamber 15 is gathered from beneath the spreader 13 and conducted from the chamber 15 by means of the pipeBG.

' That fraction of the hot oil-vaporized in the 0.1 chamber, 20 is gathered from beneath the spreader 26 and conducted fromthechamber 20 by means of the, pipe 31.

The vapor leaving the chamber 15 (in which thehigher pressure is maintained) through pipe 35. 30 at highvelocity encounters the vapor leavingv "chamber 20, throughpipe 31 at lower velocity, in compression means35 which may be of the jet compressor type, I

It, is to be understood that'in some cases it got likely will be necessary to employ other means for compressing the vapors and forcing them on,

through the otherstages of the. process.

-'Valve 32 is provided in line 30 and valve 33 is v provided in line 31 for regulating the pressures 75- within chambers 15' and 20'respectively and the flow of fluid therefrom. The admixture of vapors from the chambers 15 and 20 is conducted through pipe 40 to reaction chambers and 46 maintained under a pressure somewhat reduced from that in chamber 15.

The vaporous products entering the

reaction chambers

45 and 46 near the bottom through pipes 47 and lg having

valves

48 and 50 are subjected inside the reaction chamber to a pressure and temperature slightly reduced from that existing in the chamber 15, but sufficient to be considered cracking conditions.

It is to be understood that I may either insulate the

reaction chambers

45 and 46 or I may provide heating means to maintain a desired temperature.

During the period of reaction within vessels 45 and 46'there is formed a liquid condensate which upon depositing in the lower portion of the vessels 45 and 16 may be withdrawn by means of the pipes and 57 and the valves ,56 and 58, while there is evolved an overhead vapor fraction which may emerge through the pipe 60. The

vessels

45 and 46 are provided with open communicating means 51 and 52 of suitable size.

. The overhead vapor. conducted through pipe 60 may be delivered to dephlegmating means 61 and a liquid condensate which may be used for refluxing may be withdrawn from the bottom of dephlegmating means 61 by means of the pipe 62. while the vapor may be Withdrawn from overhead through pipe 63 and conducted through reflux exchanger 64 to be delivered to condensing means 66 by meansof pipe 65. The desired distillate may be withdrawn from condenser 66 by means of pipe 67, conducted through metering means 68 and delivered to storage.

Obviously many modifications and variations of the invention, as hereinbefore set forth, may be made without departing from the spirit and scope thereof, and therefore, only such limitations should be imposed as are indicated in the appended claims.

I claim:

V 1. In the conversion of higher. boiling hydrocarbons the process of highly heating oil under superatmospheric pressure to cracking temperature, delivering the highly heated oil into the high pressure stage of a separating zone having a high pressure stage and a low pressure stage, flashing ofi in the said'highpressure stage the more volatile products to form a vapor fraction and a hot liquid fraction, delivering the said hot liquid frac tion to the said low pressure stage, fias hing oif in the low pressure stage the more volatile products of the said hot liquid fraction to form avapor fraction and a liquid fraction, delivering the said vapor fraction at high velocity from the'high pressure stageas formed through a restricted orifice to thereby entrain the said vapor fraction from the low pressure stage as formed and therefrom delivering the total admixture to a conversion zone;

2. In the conversion of higher boiling hydro? carbons the process of highly heating oil under superatmospheric pressureto cracking temperature, delivering the highly heated oil into the high pressurestage of a separating zone having a high pressure stage and'a low pressure stage, flashing off in the said high pressure stage the more volatile products to form a vapor fraction and a hot liquid fraction, delivering the said hot liquid fraction to thesaid low pressure stage, flashing off in the low pressure stage the more volatile proddots of thesaidj hot liquid fraction to forma vapor fraction and a liquid fraction, deliveringthe said vapor fraction at high velocity from the pressure stage as formed "through trestrited orifice to thereby entrain the saidvapor fraction irom the low pressure stage as formed, delivering the total admixture to a conversion zone, evolving therein a liquid condensate and an overhead. vapor, conductinglthe said overheadvapor .to' dephlegmating means, forming therein an over-- superatmospheric pressure to cracking tempera;

ture, delivering the highly heated oil into the high pressure stage of'aseparating zone having a'high pressure 'stage and-a-lowpressure stage,

flashing oil in'the said high pressure stage the. more volatile products to form, a vapor fraction and a hot-liquid 'fractiony'delivering the said hot liquid fraction to the. said low pressure stage, flashing off in the low pressurestage the more volatile products of the said hotliquid fraction to form a vapor fraction and a liquid fraction, delivering .the saidvapor fraction at high velocity from the high pressure stage as formed through a restricted orifice to thereby entrain the said vaporfraction from' the low pressure stage as formed, delivering the total admixture to a conversion zone; evolving therein a liquid condensate and an overhead vapor, conducting the said overhead vapor to dephlegmating means, forming therein an overhead vapor and :21 a reflux condensate and conducting the said overa head vapor to condensing means to form a desired distillate while returning the said reflux condensate to a heating zone with the initial charge and highly heating the mixture.

l. In the conversion of higher boiling hydrocarbons the process of highly heating oil under superatmospheric pressure, to cracking temperature, delivering the highly heated oilinto the high pressure stage of a separating zone having a high pressure stage and a low pressure stage, flashing off in the said high pressure stage the more volatile products to form a vapor fraction and a hot liquid fraction, delivering the said hot liquid fraction to the said low pressure stage,, j flashing off in the low pressure stage the more volatile products of the said hot liquid fraction to form a vapor fraction and a liquid fraction,

' delivering at high velocity the said vapor'frac- 'said vapor fraction from the low pressure stage as formed and delivering the total admixture to a tion from the high pressure stage as formed through a restricted orifice to thereby entrain the 5; ent pressure stages of the said separating zone,

employing kinetic energy of the evolved vapor escaping from the high pressure stage to entrain;

the vapor evolved in the low pressure stage and to deliver the admixture to the conversion zone op-' erating under a pressure higher than the low pressure stage of separation.

6. In a cracking operation where the oilun- I dergoing cracking is passed successively through heating zones, a separating zone having high the proeessof deliveringchighly heated oil from thehea.tlngzones"to thehigh pressure stage of the separating zone, vaporizing therein" the more volatile components, delivering a hot liquid tractioniat cracking temperature from the high pressure stage of v:the separating zone to the low pressure stagegof: the separating zone, -va-j. Dnrizingin the said low pressure, stage themore volatile components of the said hot liquid fraction delivered thereto, conducting the vapor evolved in both stages to jet compressing means, therein interminglingfthe two vapors and utilizing the energy 0! the higher pressure vapor for in jecting theQtotal admixture into the reaction zone. under pressure above thatmaintained in the low pressure stage. 7 V 1;

7. In acracking operationwhere the oil undergoing cracking-is .passed successively through heating zones, a separating zone having different pressure stages-and a reaction zone; the process; or delivering hig ly heated on at .a cracking temperature from the heating zone into the high 7 pressure separating stage, therein/forming an overhead vapor fraction while depositing a liquid fraction, continuously conducting the said liquid fraction to another stage of separation maintained under reduced pressure,- therein forming an overhead vapor fraction and depositing a liquid fraction, delivering the vapor fraction from the said high pressure stage at high velocity through a restricted orifice tothereby entrain thevapor fraction from thesald' reduced. pres-1 sure stage anddelivering the vaporous admix; ture into the reaction zone under pressure above that maintained in the low pressure stage while withdrawing the, liquid fraction'from the said re,- ducedpressure'stage of separation, 1

8. Ina cracking operation where the oil undergoing cracking is passed successively through heating zones, a separating zone having several 1 5 stages operating under different pressures, and a. reaction zone; the process of highly heating the oil, subjecting the highly heated oil to the different pressure stages of separation to thereby combined relatively clean vapor fraction to the reaction zone under pressure above that. maintained in'the low pressure stage but below that maintained in the high pressure stagepwhile dis-- charging a carbon and coke containing liquid tractionfrom the separating zone.

' 9. In an apparatus for the conversion of hydrocarbon oils the combination of a heating coi1,13o-

a plurality of separators serially connected, means for passing oil successively through the heating coil and said separators, means for maintaining 1 a differential pressure on said separators, a reaction chamber, vapor lines for removing vapors from said separators, jet compressor mixing means for commingling said vapors and means for passing commingled vapors to the reaction chamber."

10. In an apparatus for conversion of hydro- 1 carbon oils the combination of a heating coil, a primary separator, means for passing oil from a the heating coil to said primary separator, a reaction chamber, a vapor line for conducting vapors from said separator to, the reaction chamher, a secondaryseparator maintained under reduced superatmospheric pressure lower than that of vsaid reaction chamber, means for passing unvaporized oil from the primary to said secondary separator,compressing means for 'with- 15% drawing vapors from said secondary separator which comprises heating said oil to acracking temperature under superatmospheric pressure,

separating lighter products in vapor form from unvaporized residue, expanding said residue by reducing the pressure thereon, with resulting evolution of additional vaporsyreducing the pressure on the vapors of saidlighter products'to a lower value, but one in excess of the pressure on the expanded residue, utilizing the kinetic energy of the expanding vapors of said lighter prodnets to entrain said additional vapors and increase the pressure thereon, and fractionating resultant mixed vapors under said pressure last mentioned, to produce a desired product.

12. The process of effecting the conversion of hydrocarbon oil to oil of lower boiling pointwhich comprises heating a confined flowing stream of such oil .to a cracking temperature under a high superatmospheric pressure, discharging the heated oil stream into an enlarged reaction zone wherein it undergoes further cracking under said pressure and wherein separation of vapors and liquid takes place, passing vaporous products from .said reaction zone to a fractionating zone maintained under a materially lower pressure, separately withdrawing residual liquid from said reaction zone, passing it to a second reaction zone wherein it undergoes further cracking, evolving vapors from said residual liquid at a pressure below that obtaining in said fractionating zone, and ejecting saidevolved vapors into said fractionatingzone by the energy of the vaporous products flowing thereto under high pressure from said first mentioned reaction zone, and cooling the vaporous products in said fractionating zone to recover the desired lower boiling oil therefrom.

CLAUDE W. WATSON.