Патент USA US2133344код для вставки
Oct. 18, 1933.‘ M. B. ‘COOKE PROCESS FOR THERMAL TREATMENT OF HYDROCARBONS Filed July 6,_ 1936 GM I 2 - INVENTOR Maur/cje B. C'oake ~ BY Of: ATTORN Y Patented Oct. 18, 193$ 2,133,344 UNITED' STATES ‘PATENT OFFICE» 2,133,344 ' PROCESS FOR THERMAL TREATMENT OF I HYDROCARBONS Maurice B. Cooke, Plainfleld,‘ N. J. Application July 6, 1936, Serial No. 89,089 g 6 Claims. (CL 196-67) My invention relates to a process for the distillate vapors for ultimate recovery of the de treatment of petroleum hydrocarbons to produce sired products. therefrom primarily lower molecular weight hy The character 'of the liquid ultimately produced drocarbons by thermal decomposition and syn as a desired product from petroleum hydrocarbons as disclosed in the processes or the fore 6 thesis of the hydrocarbons undergoing treatment and, more particularly, so to conduct such treat ment as to produce not only lower‘ molecular weight gasoline-like hydrocarbons suitable for use as a motor fuel of high anti-knock qualities, 10 but in addition to secure an increased yield of hydrocarbons of the aromatic series including naphthalene, benzol, xylol and toluol. When fuel is burned with no excess of air, the temperature of combustion is between 3000° F. 15 and 4000‘7 F.,Such temperatures are too high for the proposed thermal treatment productive oi’ the desired products and accordingly this tem perature must be brought down considerably in order to produce-most e?iciently the greatest yield of the desired products. In my co-pending applications Serial No. 598, 503 ?led March 12, 1932, now-Patent No. 2,046,501, _ issued July 7, 1936, to Maurice B. Cooke, and Serial No. 598,504, ?led March 12,1932, now Patent No 2,046,502, issued July 7,‘ 1936, to going applications, is essentially dependent upon the time, temperature and pressure conditions ' employed. 1 It is an object of my invention to produce low molecular weight hydrocarbon products includ 10 ing liquid aromatic products such as naphtha lene, benzol, xylol and toluol from heavier petro-f leum hydrocarbons by the direct thermal treat ment of such heavier hydrocarbons with hot com bustion gases under closely controlled conditions of time, temperature and pressure. ' It is another object of my invention to extract ‘ the desired products from the mixture of ' thermally treated hydrocarbons and combustion gases with fraction'ating and separating equip- u20 ment no greater in size than is normally employed ‘ for the extraction of such products from thermally treated petroleum hydrocarbons not ~' admixed with combustion gases. _ It is a iurther object of my invention to effect 25 Maurice B. Cooke, I have disclosed a process for in the same thermal treating zone, a secondary or the thermal treatment of petroleum hydro carbons for the production‘of lower molecular ?nal conversion‘ into desired products, of such hydrocarbons lower boiling than the desired weight gasoline-like hydrocarbons by the direct products as are recovered from the products of commingling of hot combustion gases with the the thermal treating operation and recycled to ' 30 hydrocarbons being treated. I have, shown the treating zone. ' therein that the temperature of from 3000° F.‘ It is another object of my invention to co to 4000° F. obtained by the generation of these ordinate the thermal treatment of petroleum hy gases may be lowered to a temperature more drocarbons occurring when such hydrocarbons favorable for the treatment of the hydrocarbons are directly commingled with hot combustion by' tempering or cooling the gases with steam gases, with “distillation of the liquid petroleum which may be condensed in a preiractionating hydrocarbons for the production of hydrocarbon ‘ condensing. zone with considerable advantages be >vapors to be treated, and the tempering or cool ing obtain-ed in permitting a reduction in the ing of the combustion gases to the desired treat size of fractionating and recovery equipment over ing temperature. 40 that required where normally incondensible inert tempering gases are employed. In addition‘, I have shown that the combustion gases may vbe tempered in part by passing oil to be heated for various ancillary related steps of the process in indirect‘ heat exchange with the hot gases. In particular, I have disclosed; the indirect heat ing of a relatively heavy petroleum oil to pre pare it for a topping operation; the indirect heat ing of the topped oil to enable the formation oi.’ hydrocarbon vapors for subsequent direct thermal [treatment with the tempered combustion gases; and the'indirect reheating of a cooled condensate oi the thermally treated vapors to e?ect distilla tion and permit subsequent fractionating or the - It is a further object of my invention to secure an increased yield of desired liquid aromatic and low molecular weight lhydrocarbon products‘ by close control of the character and quantity of the recycle oil returned to the primary thermal treat ing zone for retreatment with fresh oil. Other and further objects of my invention will appear from the following description and the ap- _' pended claims. I . _ The accompanying drawing-which forms part 50 of the instant speci?cation and is to be read in‘ conjunction therewith is a vschematic showing in ~ elevation with parts in section of one form of ap paratus capable of carrying out the process or my invention. ~ g . ' 2 2,138,844 and are then withdrawn from the quenching In general, I propose to generate hot gases of combustion by the admixture of combustible gases zone and the process. mixture. The resultant temperature of from 3000° F. to 40009 F. being too high for the ef iicient thermal treatment of hydrocarbon vapors to be subsequently‘mixed with the gases, I pro pose to‘reduce this temperature partially by the tially tempering the combustion gases, and as process steam for stripping in the main frac tionator. The further cooling of the reactant takes place in a series of separate zones in which the heavier hydrocarbons of the reactant are 10 condensed and from which they may be selec tively withdrawn. A portion or all of the heavy condensate formed in these separate condensing . addition of a cooler inert gas such as steam and 10 partially by passing the gases in indirect heat ex change with cooler? liquid petroleum hydro; carbons. ' - Crude oil is passed in indirect heat exchange with the hot combustion gases whose tempera zones is returned to the quench zone as re?ux for end point control and another portion‘ of this 15 heavy condensate is passed to‘ the main frac tionating tower. The uncondensed lower boil ing portion of the reactant which may be, for example, a 200° F. to 250° F. end point naphtha plus all lighter hydrocarbons and the combus 20 tion gases, is further cooled by indirect heat 15 ture is thereby lowered while the reduced crude is heated, the heated crude then being subjected to a topping operation in which the depth of the out may vary within wide limits. The topped crude, together with light and heavy recycle oil, 20 forms the ‘charge to a vaporizing coil through which it passes in indirect heat exchange with the gases, the heated" oil then being ?ashed into exchange to condense preferably‘substantially all the normally liquid hydrocarbons. The water vapors.‘ Preferably, the vaporizing coil is located in the hottest portion of the zone through which 25 the combustion gases are being passed. In view of the quantity of oil passing through this coil, it may be necessary to employ external heating means auxiliary to the combustion gases to se cure the desired vaporization. The uncondensed portion ' of the reactant is then cooled further by pass ing in, indirect heat exchange with clean water, thus generating steam which is utilized for ini with no excess of oxygen and the burning of such . resulting from condensation of steam in the mix tur is withdrawn from the separating zone to 25 which the cooled reactant is passed and the liq uid hydrocarbons of the reactant are regenera tively reheated by passing in indirect heat ex change with the reactant and then by passing The vapors resulting are directly commingled in indirect heat exchange with the hot v‘com 80 in a mixing zone with the combustion gases bustion gases, ‘the liquid- reactant being raised which, on entering this zone, have been tempered thereby in “a distillation coil to a temperature or cooled to a temperature of from about su?icient to permit vaporization at the substan 1500° F. to about 2500" F., the temperature pref , tially atmospheric'pressure under which the 35 85 erably being from about 1800° F. to about 2000” F. process is conducted. On issuing from this dis-. The mixture of hydrocarbon v'apors and com ' vtilling coil, the reactant passes directly to the bustion gases, which) for convenience I shall main fractionator. . .. In the main iractionator ‘relatively heavy hereinafter call the reactant, passes through a primary treating zone of a length su?icient to cracked gas oil is withdrawn as a bottom prod uct, light gas oil'is withdrawn"v as a sidestream, 40 provide the time element necessary to e?'ect de and the overhead product of ‘the fractionator composition of heavier hydrocarbons of the re actant into lighter hydrocarbons into desired aromatic products. The reactant is preferably subjected to the action "of the hot combustion 45 gases. in this primary zone for a period 01' from about one second to about three seconds,v de pending upon whether the temperature of these gases is at 2500° F. or a lower temperature of 50 around 1500" F. respectively.» The reactant passes from the primary treating zone into a secondary treating, or soaking zone, wherein the reactant is cooled to a temperature ,0! from about 1050" Fvto about 1800“ F.>by the spraying into the reactant of a cooler recycle oil consists of lower molecular weight gasoline-like hydrocarbons and/or hydrocarbons of the arc matic series including naphthalene,v benzol, toluol and xylol which are cooled, condensed and removed from the accumulator-separator as the desired distillate‘ product, The uncondensed portion of the fractionator overhead which will include saturated and unsaturated hydrocarbons of the para?in series such as propane-propylene, -50 butane-butylene, ethane-ethylene, as well as some hydrogen, methane and entrained gasoline like hydrocarbons is combined with the uncon densed portion of the reactant, compressed, substantially completely vaporizable‘at the re-' cooled and the light condensate resulting sepa- ' sulting temperature, or by indirect heat ex change with a cooler oil. In this secondary rated from the gases uncondensed by the com pression and cooling. The light condensate is recycled to the ?ash ‘tower vaporizing‘coll as part of the charge to that coil, is vaporized,vand treating zone the recomposition and synthesis of hydrocarbons proceeds to form not only lower molecular weight gasoline-like hydrocarbons, but, by reason of the lower temperature, a'substantial quantity ‘of hydrocarbons of the aromatic series including naphthalene, benzol, toluol and xylol.’ The time oi’ reaction in this; zone will vary from about one second to about ten seconds, depend ing upon whether the-temperature o! the reactant is about 1800° ‘F, or 1050" F. respectively. ‘ ‘_ From the. secondary treating zone, the re actant' passes into a combined quenching and separating zone wherein a cooler hydrocarbon oil is sprayed into the‘ reactant whose tempera- v then admixed with thehot combustion gases for further thermal treatment and the production of additional desired lower molecular weight hy drocarbons, particularly aromatics, since a large percentage 01' unsaturate's will be present in this recycle condensate. ‘ The gases remaining uncondensed after-the compression and cooling operation arepassed to . i an absorber wherein they are contacted under pressure with cooled light absorber oil withdrawn as a side stream from the main tractionator, the unabsorbed gases particularly the combustion ture iszquickly reduced to around 600° F. to "'100°~F.-M ~At-.the..same time and as the result‘ gases and methane being ‘released to. a fuel gas of this quenching operation, the heavy polymers, main and the rich absorption 1011 being recycled 75 tars, gums and fuel oil present are condensed to the vaporizing coil as part of the chargeto 3 2,183,344 that coil for further thermal treatment by the drawn through pipe 39 by means of a pump 40 discharging into the feed pipe 29 connecting with hot combustion gases. Referring now more particularly to the draw ‘ feed tank 33 as previously described." The feed tank 33 contains the oil which is to ing, I charge a crude by means of a pump I beheated in a vaporizing coil and after vapor Cl through a pipe 2, heat exchangers 3 ‘and 4, heat ing coi1_5 and transfer pipe 6 into fractionating ization thermally treated by direct contact with tower 1. ' combustion gases of proper temperature, and in Fuel gas is drawn by the compressor 3 through the case where the initial charge oil has been the pipe 9 adapted to take fuel gas from the subjected to an initial topping operation as pre- . viously described, consists of this topped oil such 10 10 recycle tail gas main II) or valved fuel gas inlet pipe II, and discharged through pipe I2 into the ‘ as heavy gas oil, and cracked recycle gas oil re covered in the operation of the process as will fuel gas supply tank I3. The fuel gas is dis be more fully described hereinafter. charged under pressure as needed from the sup The oil to be treated is.withdrawn from the ply tank |3 through the valved pipe |4 into the 15 mixing chamber l5 wherein it is mixed with air feed tank 33 through the pipe 4| by means 01' the pump 42 which forces the oil through the fed through a valved pipe l6 in quantities sum cient to produce complete combustion of the gas pipe 43, through the valves 44 and 45 in the pipe 43, through the vaporizing heating coil 46in the without excess of oxygen. The combustible mix ture formed burns with surface combustion on ‘chamber 2| from which the heated oil is trans the granules of refractory material H to form ferred through the pipe 41 into the ?ash tower hot combustion gases in the combustion cham-3 46. The oil circulating through the coil 46 is ber I6; These hot gases will be at a temperature heated during transit to a vaporizing tempera of. from 3000° F. to 4000° F..which'is too high for tureand at the same time the combustion gases the e?icient thermal treatment of hydrocarbon are partially cooled by indirect heat exchange with the colder oil. In view of the relatively 25 vapors in accordance with my process. The temperature of these gases may be reduced large quantity of oil passing through this heat in part by admixing therewith cooler steam fed ing coil, I may deem it‘necessary to provide addi 'into the gases through the valved pipe I9 at a ‘ tional means for heating the oil such as a tube point 20 in- the combustion chamber l3 where , still (not shown) externally of the chamber 2|, 30 complete combustion of the gas fuel air mixture has taken place. The steam thus'supplied will act as an additional heat carrier medium with the combustion gases, and has the advantage of being condensible and separable from the com 35 bustion gases and hydrocarbon vapors at normalv the quantity of vapor to be passed through the the ?ash tower 43 as operating conditions with respect to temperature may dictate. The coil 46 is preferably placed in the cham main fractionating tower. The combustion gases ber 2| in such position as to come in contact atmospheric conditions of temperature and pres-< sure. For this reason I am enabled ‘to reduce 40 partially cooled by the steam, if such cooling is so connected into the pipe 43. By such means, I 30 can obtain a very close control of the tempera ture change of the combustion gases by the coil 46. A pipe 43 controlled by a valve 50 connects the pipes 43 and 41 in order that all or part of the oil from pipe 43 may be passed directly‘ into 35 with the combustiori’gases at’their highest tem 40 desired at this time, ?ow into the chamber 2| ‘perature, although the exact positioning and and across the tubes forming the heating coil 5. arrangement of the tubes forming the coil '46 will be governed by the furnace design and by The relatively cool oil passing through the heat ing coil 5 assists in reducing the temperature of the amount of tempering of the combustion gases the combustion ‘gas and is at the same time contemplated. In the ?ash tower 48, the heated oil from heated to a vaporizing temperature preparatory to fractionation in the fractionating tower 1. pipe 41 is ?ashed into vapors and unvaporized Obviously, the heating effected in the coil 5 may ,oil, which latter forms a fuel oil and is with be supplemented- by an external tube still (not drawn through the pipe 5|, valve 52, heat ex shown) and if no topping operation is necessary changer 53 and cooler 54 by the pump 55 which discharges 'the fuel oil to storage. or if the cooling effect of the coil 5 on the com bustion gases is not deemed necessary, this coil - The hydrocarbon vapors formed in the ?ash may be dispensed with entirely. In the fractionating tower ‘I the vapors formed 55 are fractionally separated and ‘the, overhead products of desired end point ?ow through vapor pipe 22, vapor heat exchanger 3 and water cooler 23 into accumulator 24 from which re?ux is returned through pipe 25 by pump 26 to the 60 fractionating tower 1 for end point control of the fractionator overhead. Any steam condensed is discharged as water from the accumulator 24 through the valved pipe 21 and the distillate is discharged to storage through the valved pipe 26. The topped crude accumulating in the base of 65 the tower 1 is withdrawn therefrom through a tower 48 discharge therefrom at substantially atmospheric pressure through the pipe 56 into the mixing chamber 5'! wherein they are mixed with the combustion gases issuing from the' chamber 2|.‘ ‘ . The combustion gases entering the mixing chamber 51 will have been reduced in tempera ture by the steam and indirect heat exchange to a temperature between about 1500’ F’. to about .2500° F. and preferably to a temperature such that the mixture of hydrocarbon vapors ‘and combustion gases will be at a temperature of _ ' from'about 1800° F. to about 2000" F. which I have 'found is most favorable for the primary " pipe 29 by means of pump 30 and passes through, ' thermal decomposition or cracking of the heavier heat exchanger 4, vapor heat exchanger 3!, and ,, hydrocarbons of the mixture to produce lower, heat'exchanger 32 into .the vaporizing coil feed molecular weight gasoline-like hydrocarbons and 70 tank 33. 'All or part of the oil in the pipe 23 may the simultaneous synthesis of unsaturated hydro 70' be diverted therefrom by suitable manipulation carbons present ~into desired aromatic products. ' of a valve 34 in the line 29 thus causing the oil ' _The mixture of combustion gases and hydro to" ?ow through a pipe 35 in which valve 36 is carbon vapors, which I have termed the reactant opened and through cooler 31'into.a topped oil for the sake of convenience, passes from the mrz~ 75 accumulator 36 from which the oil may be with ’ ing zone 51 into the primary treating or cracking 76 2,133,344 zone 58, the time‘ of passage of the ‘reactant through which varies from between about one second at 2500° F. to about three seconds at 1500° F. ' desirable-tor the production of the desired aro matic products. The uncondensed portion 01 the reactant in the separator 81 will therefore con sist of a mixture of those saturated and unsatu The reactant leaves the primary thermal treat ing zone 58 after the proper time interval and enters the secondary thermal treating or poly rated hydrocarbons which are normally gaseous merizing zone 59 wherein the. reactant is cooled‘ to a temperature between about ‘1050" F. to about as hydrogen, nitrogen, carbon dioxide and car bon monoxide. Obviously there will also be in ' this uncondensed portion of the reactant some of .10 10 1800” F; by intimate physical commingling of a cooler oil which is sprayed into the hot reactant through a spray nozzle or other suitable means 60. The zone 59 acts as a soaking zone for the ?nal decomposition oi! the heavier hydrocarbons 15 present in the reactant and at the same time the temperature conditions existing are those which I have found are most favorable for the produc tion of desired aromatic products from the un at normal atmospheric conditions of tempera— ture and pressure and the combustion gases such the normally liquid hydrocarbons not separable therefrom under the temperature and pressure conditions in\ the separator 01. This uncon densed portion of the reactant is discharged from the separator 01 through the pipe" to 15 suitable apparatus for the recovery or light re cycle stock as will be more fully described herein after. - I ' saturated low molecular weight hydrocarbons The condensed portion or the reactant in the 20 present in the reactant. The time of passage of separator 81 is withdrawn therefrom through the 20 the reactant through the secondary treating. pipe 90 by the pump SI and is charged thereby zone will vary from about one second at 2000“ F., to about ?ve seconds at 1400° F., to aboutten through the pipe 92, cooler 04, valved pipe 92, heat exchanger 94, pipe 95, heat exchanger 53' and pipe 96 to the distillation coil 91 in the cham ‘oer 2i. If desired, the heat exchanger 84 may be 25 ing zone 59 enters a separator 6| wherein the lay-passed to the pipe 95 through the valved pipe temperature is quickly lowered to around 600° F. 98 and, likewise, a portion of the condensate in the pipev 93 may be by-passed through the valved to ‘700° F. to substantially terminate further re action by spraying into the reactant a cooler oil , pipe 99 into the pipe 43 leading to the vaporizing 30 through a suitable quench nozzle 62. The heavy coil 46 by suitable manipulation of the valves 30 shown. A valved pipe I00 connecting the pipes polymers, tars and gums of the nature or fuel oil 95 and 43 permits the by-passing of a portion of which are condensed in the separator 6| are dis charged through the valved'pipe 53 into the pipe the condensate issuing from the heat exchanger 5i and sent to storage with the fuel oil from 94 into the oil ?owing through the pipe 42 to the seconds at 1200° F. V > The reactant on leaving the secondary treat 25 35 flash ‘tower 48. ‘ . vaporizing coil 40. . Theuncendensed portion of. the reactant rises upwardly through a plurality of fractionating trays 84 countercurrent' to downflowing cooler The reactant condensate ?owing through‘ the distillation coil 91 is heated therein to a tempera re?ux oil. heated oil at low or substantially atmospheric The reactant of desired end point 35 ture su?‘lcient to permit ‘vaporization of the 40 discharges from the separaior 6i through the } pressure and is discharged through the transfer 40 pipe 65 into condensing vessel 65. The condensing vessel 66 is provided with ‘a cooling coil ‘61 into which clean cool water is passed by pump 68 through pipe 69 and cooler 45 l0. The water is heated in the coil 61 by ex change with the hot reactant and the steam _ formed is discharged through the pipe ‘II into the steam supply tank ‘I2 from which tempering steam is withdrawn at will through the pipe I9. The reactant in the condensing vessel is cooled to an extent su?lcient to condense the heavier hydrocarbons which accumulating as fractional condensate in the condensate basins ‘I3, ‘I4 and 15 may be withdrawn therefromthrough the pipes 65 ‘I6, 'I ‘I and 18, respectively, and returned in suitai ble proportions through the pipe ‘I9 to the sepa rator 6| asv re?ux by suitable manipulation'ot the valves 80, BI and 82.' _ The uncondensed portion of the cooled re 60 actant inthe condensing vessel 60 will preferably, have as its heaviest constituent a hydrocarbon distillate having about a 200° F. to a 250° F. end ' point and discharges from the condensing vessel 66 through a pipe 83, through coolers ‘I0, 84 and 65 85, and through pipe 85 into separator 81. In ‘the separator 81, the condensate resulting from the cooling of the reactant will preferably consist primarily of hydrocarbons boiling above the pentane or C5 hydrocarbons. The water re 70 sulting from condensation of the tempering steam vis withdrawn ‘from the separator 81 I through the valved pipe 00. The separator 01 like the thermal treating zones is maintained at the low or substantially atmospheric pressure which I have found is most pipe IM to the main tractionator I02. The heavy condensate separated from the re actant in,the condensing chamber 65 may be transferred in whole or in part through the pipe I03 controlled by the valve I04 by suitable ma 45 nipulation of the valves 8|, 82 and I04. In thus returning the heavy condensate from the pipe I03 to the iractionating tower I02, I am enabled to e?ect sharp separation of suitable recycle stock such as heavy cracked gas oil for recycling to the 50 vaporizing coil. Steam from the supply tank ‘I2 may be injected into the tractionator I02 through the pipe I05 by opening the valve 200. From the tractionat‘or I02 there is withdrawn a relatively heavy recycle oil such as cracked gas‘ 55 oil through the pipe I00 by means of the pump I01, the oil being cooled by the heat exchanger 32, and cooler I08. Aportionot the oil in the. pipe I06 passes through the pipe I09 controlled by the valve IIO into the pipe 02 of the separator 60 0| for use as quench oil. Another portion of the oil in the pipe I00 is passed through the pipe III controlled by the valve II2 into the spray nozzle 00 from which it is discharged to control the tem perature of the reactant in the secondary treat v65 ing zone 50.? ; _' The relatively heavy oil withdrawn from the Iractionator I02 through the pipe I06 is most suitable as recycle oil and?the greater quantity or this oil passes through the pipe I06 and from thence through the pipe .7 I12 controlled by the valve II4 into ‘the Ieed'itank 33 from which a vapor return line I I5 leads to the main fraction; atorq I02. I have found; that for most satisfac toryioperation of my process, the'ratio of heavy 75 2, 1 38,344 recycle oil to fresh oil in the feed tank 33 should be from about one to one, to three to one. A light gas oil is withdrawn as a sidestream .. p 5 heat exchange‘ with 011 being passed to various stages of thelprocess and by the admixture with the combustion gases of a cool inert gas such as from the fractionator I02 through the pipe II6 steam which is readily condensible and may be by means of a pump III and passes through a ‘ employed as ‘a heat carrying medium withoutre cooler lit to an absorber II8 for use as cooled ' quiring an increased size of the fractionating ap~ I lean absorption oil as will be more fully described paratus. hereinafter. The overhead products of the fractionator I02 10 are discharged therefrom through the pipe I20 It willbe observed ‘that certain features and sub-combinations are of utility and may be Iem-' ' ployed without reference to other (features and 10 and pass through the heat exchanger 3| and sub-combinations. This is contemplated by and cooler I2I to the separator I22 from which con— is within the scope of my claims. It is further obvious that various changes may be made in details ‘within the scope of my claims. This is densate is returnedthrough pipe I23 by means of pump’ I24 to the fractionator I02 as re?ux for 15 end point control of the fractionator overhead. Water is withdrawn from the accumulator I22 through the pipe I25 controlled by the valve I26 and the distillate, which I shall refer to as heavy distillate to distinguish it from the light distil 20 late recovered from the‘ uncondensed gases in the. accumulator I22 and separator 81, is discharged through the pipe I21 by the pump I23 as the de sired aromatic liquid product. : contemplated by and is ,withinthe scope of my 15 claims. It is further obvious that various changes may be made in details within the scope of my claims without departing from the spirit of my invention. It is, therefore, to be under stood that my invention is not to be limited to the 20 speci?c details shown and described. ~ Having thus described my invention, what I i, claim is: The gases remaining uncondensed in the ac 1. A process for thermally treating petroleum ‘ 25 cumulator I22 will consist of hydrocarbons both , hydrocarbons including the steps of generating 25 » saturated and unsaturated, uncondensible at sub combustion gases having a substantially complete stantiallyatmos'pheric pressure and at the tem- . absence of oxygen, cooling the hot gases to a tem perature of the cooling water employed. These gases will contain entrained low molecular weight 30 gasoline-like hydrocarbons and are discharged through the pipe I23 adjoining the pipe 89 feed ing the suction side of the compressor I30. The mixture of combustion gases and hydrocarbon vapors‘ is compressed and discharged through was pipe I3I and cooler I32 into separator I33 from which the light distillate previously referred to is discharged through the pipe I34 controlled by the valve I35 into the pipe I36 through which perature of from about 1500° F. to about 2500° F., admixing dry hydrocarbon vapors with the cooled gases to form a reactant at cracking tempera 30 ture, soaking the reactant at substantially crack ing temperature for from about one to about three seconds to ‘form normally gaseous, unsat urated hydrocarbons, cooling the reactant to a lower and polymerizing temperature of from .35 reactant at the lower temperature for from about about 1050° F. to about 1800° F., maintaining the one to about twelve seconds to polymerize nor, ?ows rich absorption 011 being delivered from the mally gaseous, unsaturated hydrocarbons to 40 absorber II3 to the pipe II for recycling to the" ' higher molecular weight, aromatic hydrocarbons, vaporizing coil l6. » V , quenching the reactant to a temperature below The uncondensed ,gases in the separator I33 are 700° F. and recovering aromatic hydrocarbons from the'quenched reactant. discharged through the pipe I31 into the absorb 2. A'process for thermally treating petroleum er I I9 wherein residual hydrocarbons suitable for 45 recycling to produce the desired aromatics are hydrocarbons including the steps of generating absorbed in the lean oil fed to the absorber combustion gases having a substantially complete through the pipe H0 and returned with the rich absence of oxygen, cooling the hot gases to a oil through the pipe I 36 to the vaporizing coil. temperature of from about 1800° F. to about 2000’ The unabsorbed gases are discharged through F., admixing dry hydrocarbon vapors with the the pipe I33 and pressure relief valve I33'into the cooled gases to form a reactant at cracking tem 6.0 fuel gas main I0 from which they may be dis perature, soaking the reactant at substantially charged to the atmosphere by opening the valve the cracking temperature for from about one to "I40, or picked up by the compressor 8 by opening about three seconds to form normally gaseous, the valve “I. "unsaturated hydrocarbons, cooling the reactant to I It will be observed that I .have accomplished a lower and polymerizing temperature of from 55 the objects of my invention and have provided a about 1200° F. to about 1800” F., maintaining the 55 process for thermal treatment of petroleum hy ‘ reactant at the lower temperature for from about drocarbons by the direct commingling of such one to about twelve seconds to polymerize said hydrocarbons with combustion gases under care normally gaseous, unsaturated hydrocarbons to 60 fully controlled conditions of time and tempera . higher molecular weight, aromatic hydrocarbons, 60 ture. I have provided a process by which the quenching the reactant to a temperature below conversion and synthesis :of the hydrocarbons is ‘700° F. to substantially terminate further reac effected by the thermal treatment of the com jbustion gases so as to produce an increased yield tion and recovering aromatic hydrocarbons from the quenched reactant. 3. A process for thermally treating petroleum 65 of liquid aromatic products such as ‘naphthalene, ' benzol, toluol, and xylol, together with liquid low ' hydrocarbons including the steps of generating molecular weight gasoline-like hydrocarbons combustion gases having a substantially complete suitable for use as motor fuel of high anti-knock rating. I have provided a process in which the absence ‘of oxygen, cooling the hot gases to a temperature of from about 1500° F. to about 70 yield of the desired liquid aromatic products is increased through the recovery and recycling of unsaturated hydrocarbons formedin the reactant by' the" thermal treatment. I have also provided a unitary process in which the temperature of 75 .the combustion gases is controlled by indirect 2500° F., admixing dry hydrocarbon vapors with 70 the cooled gases to form a reactant at cracking‘ temperature, soaking the reactant at substan tially the cracking temperature for from about one I. to about three seconds to form normally gas eous. unsaturated hydrocarbons, cooling the re 76 6 2,138,844 about 1050" F. to about 1800° F., maintaining the temperature, maintaining the reactant at sub stantially the mixing temperature for from about reactant at the polymerizing temperature for one to about three seconds to form lower molecu-. , from about one to about twelve seconds to poly lar weight hydrocarbons, including normally gaseous, unsaturated hydrocarbons, cooling the actant to a‘ polymerizing temperature of from merize the normally gaseous, unsaturated hydro carbons to higher molecular weight aromatic hy- - reactant to a lower temperature of from about ' drocarbons, quenching the reactant to a temper ature below ‘700° F. and cooling the quenched re actant and separating therefrom a light con 10 densate comprising mainly normally liquid hy drocarbons of gasoline boiling range and a heavy condensate comprising mainly hydrocarbons boil ing above the gasoline boiling range, fractionat ing the condensates to obtain a plurality of suc- , higher boiling hydrocarbon fractions, '15 cessively recovering from one 01 said fractions desired aro 1200° F’. to about 1800° F., polymerizing the react ant at lower temperature for from about one to about twelve seconds to form normally liquid aro matic hydrocarbons from said normally gaseous, ' 1. unsaturated hydrocarbons, quenching the react ant‘ to a temperature below 700° F. to substan tially terminate further reaction and recovering liquid aromatic hydrocarbons from the quenched reactant. ' ‘ matic hydrocarbons, vaporizing another of said 6. A process for thermally treating petroleum hydrocarbons including the steps of generating fractions and admixing the vapors formed with said ?rst mentioned cooled gases as dry hydro 20 carbon vapors. 4. A process for thermally treating petroleum 2500° F., admixing dry hydrocarbon vapors with hydrocarbons including the steps 02 generating combustion gases having a substantially complete ‘ II combustion gases having a substantiallycom plete absence of oxygen, cooling the hot gases to a temperature of from about 1500” F. to about the cooled gases to form a reactant at cracking , temperature, maintaining the reactant at sub absence of oxygen, cooling the hot gases to a stantially the mixing temperature for from about one to about three seconds to form lower boiling 25 temperature or from about 1500° F. to about 2500° ~ hydrocarbons including normally gaseous, unsat F., admixing dry hydrocarbon vapors with the cooled gases to form a reactant at cracking tem perature, soaking the reactant at substantially the mixing temperature for from about one to about 30 three seconds to form lower molecular weight - hydrocarbons including normally gaseous, unsat urated hydrocarbons, cooling the reactant to,’ a lower and polymerizing temperature of from about 1050a F. to about 1800° F., maintaining the 35 reactant at the lower‘ temperature for irom about one to about twelve seconds to polymerize said normally gaseous, unsaturated hydrocarbons to ' normally liquid aromatic hydrocarbons, quench ing the reactant to a temperature below 700° F. 40 and recovering liquid aromatic hydrocarbons urated hydrocarbons, cooling the reactant to a lower temperature of from about 1050° F. to about 1800° F., maintaining the reactant at the lower temperature for from about one to about twelve seconds to polymerize said normally gaseous un saturated hydrocarbons to normally liquid aro matic hydrocarbons, quenching the reactant to a temperature below 700° F. and cooling the quenched reactant and separating therefrom a light condensate comprising mainly normally liquid hydrocarbons of gasoline boiling range and a heavy condensate comprising mainly hydro carbons boiling above the gasoline boiling range, fractionating the condensates to obtain a plu rality of successively higher boiling hydrocarbon from the quenched reactant. 5. A process for thermally treating petroleum 1 fractions, recovering ‘from one or said fractions hydrocarbons including the steps of generating desired liquid aromatic hydrocarbons, vaporizing combustion gases having a substantially complete: another of said fractions and admixing the vapors temperature of from about 1800° F. to about dry hydrocarbon vapors. absence of oxygen, cooling the hot gases to a ' formed with said ?rst mentioned cooled gases as 2000° F., admixing dry hydrocarbon vapors with the cooled gases to form a reactant at cracking MAURICE B. COOKE.