US2019448A

US2019448A - Art of and apparatus for converting hydrocarbons

Info

Publication number: US2019448A
Application number: US475105A
Authority: US
Inventors: William L Gomory
Original assignee: Standard Oil Development Co
Current assignee: Standard Oil Development Co
Priority date: 1930-07-15
Filing date: 1930-08-13
Publication date: 1935-10-29
Anticipated expiration: 1952-10-29

Description

oct. 29, 1935. l A

ART OF AND APPARATUS FOR CNVERTING HYDROCARBONSv Filed Aug. -15, 1950 3 Smeets-Sheetl Oct. 2,9, 1935. v w; GoMoRY y 2,019,448

A-RT OF AND APPARATUS FOR CONVERTING IIYDROCARBONS Figed Aug. 15, 1930 s sheets-sheet PRENIN TER Oct. 29, 1935. w. L. GoMoRY 25019443 ART OF AND APPARATUS FOR CONVERTING HYDROACRBONS' FiLed'Aug. 1s, 195o 3 sheets-sheet 5 Patented Oct. 29, 1935 PATENT OFFICE ART F AND APPARATUS FOR CONVERTING HYDROCARBONS William L. Gomory, Paris, France, assignor to Standard Oil Development Company, a corporation of Delaware Application August 13, 1930, Serial No. 475,105

In Great Britain July 15, 1930 l s claims. (Cl. 19e- 48) This invention' relates to an improved process and apparatus for 'the treatment of hydrocarbons, and more especially to the treatment of petroleum oils for the production of low boiling products.

According to my invention the oil is subjected to vaporization at atmospheric or super-atmospheric pressure in a vaporizing zone, from which there is recovered a reflux condensate that is subjected to cracking conditions of temperature, pressure and time in a heating and cracking zone, which may consist of a heating coil arranged in conjunction with one or more conversion chambers, or may consist of a coil which forms a combined heating and cracking zone. The products from the heating and cracking 'zone are Ydischarged into the vaporizing zone, from which the vapors are removed, e. g. to a fractionator or fractionators, and the residue Withdrawn. If desired the oil, before being subjected to vaporization, is passed under pressure through an auxiliary heating zone, preferably in the form' of a coil. Moreover the residue obtained in the evaporaior is subjected to cracking conditions of temperature, pressure, and time in the heating and cracking zone; or such residue may be subjected to a destructive hydrogenation treatment in any suitable manner, for example as described in the specification of my (zo-pending application Serial No. 475,099, led August 13, 1930.

Furthermore, the residue obtained in the evaporator may be introduced either wholly or partly into the inlet of the heating and cracking zone; or the said residue may be introduced at an intermediate point or points of the coil which either forms the heating zone or a combined heating and cracking zone. The residue may also be introduced into the stream of oil at the outlet end of the coil. The residue may moreover be introduced into the system at two or more of the positions above mentioned.

The reflux condensate from the vaporizing zone may be Vintroducedeither Wholly or partly into the inlet of the heating and cracking zone; or the said reflux condensate may be introduced at an intermediate point or points of the coil which forms either the heating zone or a combined heating and cracking zone. The reflux condensate may also be introduced into the stream of oil at the outlet end of the coil. The reflux.. condensate may however be introduced into the system at two or more of the positions above mentioned.

lIn cases where there are separate heating andv cracking zones the quantity of residue and/or reux condensate, introduced into the stream of heated oil passing from the heating zone, e. Vg.

ya coil or series of coils to the cracking zone, e. g.

one or more conversion chambers, is so regulated that it will control the temperature of the oil in the cracking zone. A further means of effecting such regulation of the temperature, consists in that part of the oil from the heating coil or series of coils is taken from an intermediate point in such coil or series of coils and'is intro- 10 `duced into the stream of heated oil passing from the heating coil or coils into the conversion chamber or chambers. The temperature of the stream entering the evaporator can be controlled in a similar manner.

In cases where the heating and cracking zone consists of a coil or series of coils only, lthe quantity of the residue and/or reflux condensate introduced into the stream of heated oil vor Vcracked products passing from the heating and cracking coil or coils to the evaporator, is so regulated that it will control the temperature of the oil before the same enters into such evaporator, or will control the temperature of the oil in the evaporator. Furthermore part of the oil passing through the coil or coils may be taken from an intermediate point of the coil or coils and introduced into the stream of heated oil passing to the evaporator, in order to regulate thevtemperature thereof. I

The reflux condensate before it is introduced into the heating and cracking zone, or into the cracking zone, as above mentioned, is subjected to distillation at atmospheric or super-atmos pheric pressure for the purpose of separating the light fractions from the same.

The' light vapours separated from the reux condensate are introduced into the fractionator or fractionators either separately or together -1 with the vapours obtained in the vaporizing zone. 40 Or if desired such light vapours may be introduced into the vaporizing zone. Moreover the vapours obtained from the reflux condensate may be partly introduced into the vaporizing zone, e. g. the heavier fractions, and partly into the fractionator or fractionators, e. g.v the' lighter fractions.r Or the said light vapours may be frac-I tionated in a separate fractionator.

'I'he residue removed from the vaporizing zone is advantageously subjected to a second vaporization at atmospheric or super-atmospheric pressure, the vapours so obtained being introduced intok the first vaporizing zone, the nal residue being withdrawn and if desired subjected to de structive hydrogenation in any suitable manner,

my co-pending application Serial N0. 475,099, led August 13, 1930.

The vapours obtained from the residue in the second vaporizing zone may be introduced 'into the fractionator or fractionators.- The vapours obtained from the residue in the second vaporizing zone may be separately fractionated or they may be partly introduced into the first vaporizing zone and partly into the fractionator or fractionators receiving the vapours from the evaporator, e. g. the heavier and lighter fractions respectively.

In some cases it may be desirable to subject the residue from the first vaporizing zone to a second vaporization at atmospheric or superatmospheric pressure in such a manner as to vaporize all volatile matter contained in the residue, the resulting solid residue being removed and the vapours introduced into the first vaporizing zone or into the fractionators or into both the rst vaporizing zone and the fractionators. The vapours obtained from the residue vin the second vaporizing zone are advantageously subjected to fractional condensation, the uncondensed vapours being passed into the first vaporizing zone or into the fractionators, or into both the first vaporizing zone and the fractionators, and the condensed heavier fractions being returned to the system with or without subjecting them to distillation in a still, which may `be the still in which the reflux condensate from the rst vaporizing zone is re-run.

In all the above forms of my improved process, the vapours may be separated into good endpoint gasoline and other valuable fractions by passing them through fractionators and rectifiers provided with controlled cooling, which cooling may be effected either by the feed oil or by means independent thereof.

A novel feature of my invention comprises subjecting the uncondensed vapours and gases to dissociation and conducting the dissociated vapours and gases toa destructive hydrogenating plant in order to use the same in the destructive hydrogenation of hydrocarbons, as shown in my co-pending application Serial No. 475,102, filed August 13, 1930.

The reux condensate obtained in the fractionator or fractionators may be introduced into the vaporizing zone for redistillation.

In cases where the heating and cracking zone consists of separate heating and cracking zones, the oil may advantageously be conducted through a continuous heated coil and one or more heatinsulated conversion chambers, wherein the oil is maintained under pressure at the necessary cracking temperature. In such conversion chambers, the material underl conversion may be thoroughly agitated during the reaction. Thus the material under conversion may be circulated from the lower part to the upper' part or top of the conversion chamber or chambers. Or it may be circulated from the conversion chamber or chambers into the coil and back into the chambers.

A uniform super-atmospheric pressure may be maintained in the coil and in the conversion chambers, where such are employed, or a higher pressure may be maintained on the coilthan in the conversion chamber or chambers. The pressure in the vaporizing zone may be maintained at a lower value than that in the conversion chamber or chambers, or in the coil or coils in cases where no separate conversion chamber is employed. The pressure in the still, in which the for example, as described in the specification of reflux condensate from the first or primary vaporizing zone is re-run, is maintained at a higher value than that in the rst vaporizing zone or in the fractionators. Furthermore a higher pressure is advantageously maintained in the auxiliary 5 or secondary vaporizing zone than the first or primary vaporizing zone. Generally speaking dif ferent pressure conditions may be maintained in the various parts of the system. Moreover in cases where a coil forms a combined heating and cracking zone, uniform pressure conditions may be maintained in the coil and in the evaporator. In a preferred form of my improved process the hot cracked products from the heating and cracking zone are introduced without substantial loss l5 of heat into a vaporizing zone in which the introduced charging material is subjected to vaporization together with the hot cracked products and from which the vapours and the residue are separately removed, the residue being then introduced into a second vaporizing zone wherein it is subjected to a second vaporlzation. The vapours from the second vaporizing zone can be introduced into the first vaporizing zone. Furthermore the vapours obtained in the second vaporizing zone are subjected to fractional condensation, the uncondensed vapours being passed into the first vaporizing zone or into the fractionator or fractionators or into both the rst vaporizing zone and the fractionator or fractionators, the convdensed heavier fractions being returned to the system with or without subjecting the same to distillation preferably vin the still in which the reflux condensate from the first vaporizing zone is re-ru-n. e My said invention comprises a process wherein the oil is subjected to cracking conditions of temperature, pressure and time whilst it is conducted through a continuous heated coil and one or more heat-insulated conversion chambers, the 4o oil or material under conversion being circulated from the lower part to the top or upper part of the conversion chamber or chambers.

The invention further comprises a process which consists in heating the oil under superatmospheric pressure to a decomposing temperature whilst passing it through an elongated passageway, and if desired also through a heatinsulated conversion chamber o-r chambers, introducing the products into a vaporizing zone, then separating and separately removing vapours and liquids, condensing the vapours and destructively hydrogenating the liquids.

The invention furthermore includesa process for treating oil, e. g. for the production of low 5 5 boiling hydrocarbons, such process comprising cracking the oil7 leading the products under reduced pressure (which may be super-atmospheric pressure) into a vaporizing zone, separating the f low boiling and other products from the residue and subjecting the residue to a destructive hydrogenating treatment. In cases where the cracking is effected in the coil, the oil may be cracked in the vapour phase. Also a reflux `condensate can be recovered in the vaporizing zone and continuously returned in a heated condition to the cracking zone. The invention moreover includes a process which consists in vaporizing the oil at atmospheric or super-atmospheric pressure ina vaporizing zone, recovering a reflux' 70 condensate, cracking the reflux condensate, in-

troducing thecracked products into said vaporizing zone, separately removing vapours and liquids, condensing the vapours and destructively hydrogenating the liquids.

The prent invention also comprises suitable apparatus for carrying into practice. the several forms of my improved process.

In order that the invention may be fully understood reference will be made to the accompanying drawings which illustrate in diagrammatic form with parts inV section preferred apparatus fo-r carrying my improved process into practice.

Referring toFigure 1 which shows an arrange' ment of the heating and cracking zone and evaporator in accordance with the invention, the oil to be treated is forced by means of a pump A through line B into cooliru.r coil C which is arranged in the upper part of an evaporator D. Feed oil from the cooling coil C may be passed into the evaporator D through branch line S or part of the feed oil may be passed through line E into the inlet end of the section G of a heating and cracking coil F which comprises three pipe sections G, H and J. The oil passes first through section GV then through section H and finally l through section J. Cracked oil is discharged from section J through line K into the evaporator D which preferably has baffle plates D suitably disposed therein to ensure a thorough contact between ascending vapour and descending liquid. Steam may be injected into the vaporizer through spray pipe T. Uncondensed vapours are withdrawn from the evaporator D through line L to fractionators and condensers (not shown), whilst the unvolatilized residue formed in the evapora-v tor is withdrawn therefrom through valved line M and passed to a destructive hydrogenation treatment or otherwise suitably disposed of. .The reux condensate produced in the evaporator is collected in a. pan N from which it is withdrawn by means of pump O and forced through line P into line E whereby it is conducted to the inlet of the coil that is, the inlet of section G. Part of the reflux condensate may be passed to an intermediate point of the vcoil such as the inlet of section J Athrough branch line Q. Or a part of the refluxmay be introduced into the end of the coil, for example, into discharge line K, by means of branch line R. Part of the oil passing through the coil may be withdrawn from an intermediate point thereof say from the outlet of section G through line U and introduced into the stream of oil passing through line K from the outlet of the coil to the evaporator.

Referring to Figure 2, which shows a more fully developed form of apparatus in which the-oil is cracked in separate heating and cracking zones, the oil to be treated is drawnfrom any convenient source of supply I by means of a pump 2 and is forced through line 3 into a heating coil 4 located in a furnace setting 5, the oil then passing through line 6 into an evaporator 1. Valved bypass lines 90. 9i and 92 are provided in line 3 whereby a regulated amount of feed oil may be sent through cooling coils 8 and 9 located in the upper parts of the fractionators ID and II respectively and thence through line I2 into line 6. A by-pass line I3 is also provided in line 3 whereby all or part of the feed oil may be passed directly to the evaporator 1 without passing through heating coil 4. A heating -coil I 4 is provided in the lower portion of evaporator 1. Moreover steam may be injected into the evaporator through spray pipe I5. A cooling coil I6 is provided in the upper portion of the evaporator 1 are independent of the supply of feed oil. Baille plates I1 are suitably disposed within the evaporator 1 to ensure a thorough intermingling of ascending vapour with descending liquid and the evaporator is advantageously heat insulated. Re- 5 ux condensate formed in the evaporator 1 is 'collected in a pan I 8 from which it is withdrawn through line I9 by means `of a pump 20. Reflux condensate is forced by reflux pump 2I through line 22 into the inlet of the furnace coils 23 which are located in a suitable furnace setting 24. The furnace coils 23'comprise three sections 25, 26 and 21 which are situated in different positions in the furnace and feed oil from cooling coil I6 `is passed to the inlet of the furnace coils 23 through line- 28 as described in connection with Fig. 1. The furnace coils may advantageously be built up of straight pipes in accordance with standard practice, e. g. with the ends of the pipes extending through the flue walls and suitably 2o chambers 30, 32 may be operated in series or in l parallel.

Reflux condensate from the evaporator 1 may also be passed by means of pump 36 through line 31 to the inlet of the furnace coils 23 and the l reflux condensate may be passed to intermediate points of the furnace coils through branchlines 38 and 39 or to the outlet end of the furnace coils through branch lines 49 and 4I, or through branch line V22' into the stream of products passing to the evaporator. Heated oil may bewithdrawn from an intermediate point of the furnace 'coils 23 through line 42 and passed to the con- 'version chamber through line 29.

45 Residue is withdrawn from the bottom of the `evaporator1 through line' 43 and maybe with'v drawn from the Isystem' by line 44 or passed through line 45 to the inlet of the furnace coils 23 by means of residue pump 46. Said residue 50 may be passed to an `intermediate point of the furnace coils 23 through branch pipe 41 or to the outlet of the furnace coils through branch pipes 48 and 4I).

Oil undergoing conversion in the conversion 5,5'

chambers 30. 32 may be agitated during the reaction with the aid of agitators or by a withdrawal of oil therefrom by means of pump 52 through branch lines 49, 50 and line 5I and circulation of such oil through line.53 back to the 60- inlet of the conversion chambers, Vor through lines 53, 53' and branch lines 53a, 53h, fr om the lower to the upper part of the conversion chambers, or such oil may be circulated through line 'i 45 to the inlet of the furnace coils 23 and thence 65 back to the conversion chambers through line 29. Vapour from the evaporator 1 passes through line 54, having a pressure control valve 55, into the lower portion of fractionator I I from the upper portion of which vapour is withdrawn by line 56 to a second fractionator I0. Cooling coils 58 and 59 are provided in the upper portions of the fractionators In and II- respectively to provide cooling means independent of the supply of feed oil whilst spray pipes 60, are provided in the lower portion ofthe fractionators for the injection of steam. The'fractionators I0, Il are heat-insulated. Condensate from the fractionators Il) and vIl is withdrawn through coolers 6| and 62 to storage whilst vapour from fractionator ID is withdrawn through line 63 to a condenser 64 from which condensate is passed to tank 93. Incondensable gas is separated from condensate in tank 33 and is withdrawn through line 51. Preferably the incondensable gas is used as a makeup gas in a destructive hydrogenation plant. The vapours and gases not condensed may be subjected to dissociation and the dissociated vapours and gases are conducted to a destructive hydrogenating plant in order to use the same in the destructive hydrogenation of hydrocarbons, as shown in my co-pending application Serial No.

` 475,102, med August 13, 1930. L

Part or all of the condensate from the frac- Vtionators I0 and Il may be passed by pump 80 tothe evaporator 1 through line 19.

When it is desired to subject the reflux 'condensate from evaporator 1 to distillation prior to its return to the furnace coils 23, the reflux condensate is passed through line 65 into the re-run still 66 into which steam can be passed through line 61 and which still can be heated directly or otherwise. Residue from the re-run still 66 may be withdrawn from the system through line 56 or returned to the furnace coils through line 68" and line 31.

Vapour is withdrawn from the re-run still 66 through line 69 to fractionator ll or'all or part of the vapour may be passed through branch pipe 10 to the evaporator 1.

In cases where it is desired to subject the residue from the evaporator 1 to a second vaporization, such residue is Withdrawn from the evaporator by means of pump 12 and passed through lines 1I, 12 and branch line 13, into auxiliary evaporators 1d and 15, which can be lheated by the injection of steam through spray pipes 16 or by direct heat or both. Final residue from the auxiliary evaporators is withdrawn by pump 94 through line 11, and 'is passed to a hydrogenation plant or is otherwise suitably disposed of. Vapour -from the auxiliary evaporators 14, 15 is withdrawn through line 18 and is passed either to evaporator 1 through line 3l or into ractionator H through branch lines 82,. 83. Or, if desired, such vapour may be passed through line 84 to a fractional condenser 85 from which uncondensed vapours are returned through line 86 either to the evaporator` 1 or to the fractionator l l. The fractional condenser 85 is heat-insulated and is provided with a cooling coil 85 in the upper portion thereof, and with a spray pipe 85" for direct steam in the bottom thereof.` The condensed heavier fractions from the fractional condenser 85 are passed by pump 81 either to the re-run still 66 through line 86 or to the furnace coils 23 'through

lines

89, 68"and 31.

Referrirgnow to Figure 3 it will be seen that the furnace coils 23 comprise both the heating and the lcracking zones and that the conversion 'chambers have been dispensed with. Gen- Verally speaking, however, the operation of the plant is the same as that shown in Figure 2 and 'like reference numerals have been used to design'ate like parts of the apparatus. According to the apparatus shown in Figure 3, the heated and temperatures and pressures to be used will vary according to the nature of the material undergoing treatment and the products desired. The oil may be -heated in the coils to temperatures ranging from 750 to approximately 1500 F. 5 under a pressure of from 50 to 3000 pounds per square' inch or more, whilsta temperature of approximately 750 to 850 F. or more and a pressure of 50 to 3000 pounds or more may be maintained in the conversion chambers. 10

In the operation in which the conversion chambers are dispensed with the oil may be subjected in` the cracking zone to temperatures of the order of 750 to 1500 F. at pressures of 50 to 3000 pounds per square inch or more, and at- 15 mospheric or super-atmospheric pressure of 500 pounds per square inch or more can be maintained in the vaporizer. Valves are suitably disposed throughout the apparatus to control the flow of oil to the different parts of the system and to enable any desired pressure to bemaintained therein.

All the lines conveying oil into the heating and cracking coils or to the outlet thereof or into the conversion chambers Where such are employed, 25 are provided with check valves to prevent the hot products from backing into these lines Whilst all the lines conveying hot oil are heat-insulated.

I claim:-

1. A process for the treatment of hydrocarbons 30 which comprises subjecting fresh charge oil to vaporization under pressure Withoutlcracking in a chamber dividedinto a dephlegmating zone and a vaporizing zone, recovering a reflux condensate from the dephlegmating zone and sub- 35 jecting the same to cracking conditions of temperature, pressure and time in a heating and cracking zone comprising a heating coil and a conversion chamber, discharging the resulting products from the conversion chamber into said 40 vaporizing zone, removing the vapors, separately withdrawing the residue from the vaporizing zone and returning the lighter fractions of the residue to said heating and cracking zone.

2. A process for the treatment of hydrocarbons 45 which comprises subjecting fresh charge oil to vaporization without cracking in a chamber divided into a dephlegmating zone and a vaporizing zone, recovering a reflux condensate from the dephlegmating zone and subjecting the same to 50 cracking conditions of temperature, pressure and time in a heating and cracking zone comprising a heating coil and a conversion chamber, discharging the resulting products from the conversion chamber into said vaporizing zone, re- 55 moving the vapors, separately withdrawing the residue from the vaporizing zone, returning a portion of the residue to the heating and cracking zone, vaporizingl another portion of the residue in a second vaporizing zone, introducing vapors from the said second vaporizing zone into the dephlegmating Zone of the first vaporizing chamber, and removing the residue from the said second Vaporzing zone.

3. A process for the treatment of hydrocarbons which comprises subjecting fresh charge oil to vaporization Without cracking in a chamber divided into a dephlegmating zone and a vaporizing zone, recovering a reflux condensate from the 70 dephlegmating zone and subjecting the same to cracking conditions of temperature, pressure and time in a heating and cracking zone comprising from the vaporizing zone, returning a portion ot the residue to the heating and cracking zone, 'distilling another portion of the residue in a second vaporizing zone, removing vapors from the said second vaporizing zone and fractionating the same, and removing residue from the sai second vaporizing zone.

4. A process for the treatment of hydrocarbons which comprises subjecting fresh charge oil to vaporization without cracking in the chamber divided into a dephlegmating zone and a vaporizing zone, recovering a reflux condensate from the dephlegmating zone and subjecting the same to cracking conditions of temperature, pressure and time in a heating and cracking zone comprising a heating coil and a conversion chamber, discharging the resulting products from the conversion chamber into said vaporizing zone, removing the vapors, separately withdrawing the residue from the vaporizing zone, returning a portion of the residue to the heating and cracking zone, distilling another portion of the residue in a second vaporizing zone, and removing vapors from the said second vaporizing zone, subjecting these Vapors to fractional condensation and returning the condensate to the heating and cracking zone, and subjecting the uncondensed vapors from the first fractional condensation zone to fractional condensation in a second fractional condensation zone.

5. A process for the treatment of hydrocarbons which comprises subjecting fresh charge oil to vaporization without cracking in a chamber divided into a dephlegmating zone and a vaporizing zone, recovering a reiiux condensate from the dephlegmating zone, subjecting the same t0 cracking conditions of temperature, pressure and time in a rheating and cracking zone, comprising a heating coil and a conversion chamber, discharging the resulting product from the Vconversion chamber into said vaporizing zone, removing the vapors, separately withdrawing the residue from the vaporizing zone and returning the same to an intermediate point in the heating zone.

6. A process for the treatment of hydrocarbons which comprises subjecting fresh charge oil to vaporization Without cracking in a chamber divided into a dephlegmating zone and a vaporizing zone, recovering a reflux condensate from the dephlegmating zone, subjecting the same to cracking conditions of temperature, pressure and time in a heating and cracking zone, comprising a heating coil and a conversion chamber, discharging the resulting products lfrom the conversion chamber into said vaporizing zone, removing the vapors, separately withdrawing the residue from the vaporizing zone and returning the same without added heating to .the conversion chamber.

7. Apparatus of the character described comprising a heating means and means for supplying oil under pressure to the inlet of said heating means, means for receiving the heated oil from said heating means, the second means being adapted to maintain the oil at cracking temperature and under pressure, said second means being provided with outlet and inlet connections at opposite ends thereof attached to a pump to allow circulation of the .contents thereof, means 5 into which the products from the second mentioned meansare discharged under reduced pressure, the said third means being adapted to allow vaporization and separation of vapors, reflux condensate and residue, said third means being pro- 1a vided with means for separately withdrawing vapors, reiiux condensate and residue, and being also provided with cooling means in the top and heating means in the bottom thereof, a plurality of means for successively receiving th'e vapors 15 from said third means and also for receiving charging oil to cause the latter to flow in countercurrent direction yto said vapors and to be delivered through the above mentioned cooling means located in said third means to said heating 20 means, means for supplying liquids from said third means to the inlet and outlet of said heating means and to intermediate points thereof, means for supplying reux condensate into the stream of products discharged from said second means 25 into said third means, means for discharging oil from an intermediatepoint of said heating means into the stream of products passing from said heating means to said second means and separate distilling means connected to said third means 30 for separately receiving reux condensate and residue from said third means.

8. Apparatus of the character described comprising a heating and converting means adapted for heating and maintaining oil at cracking tem- 35 perature and under pressure and means for supplying oil under pressure to the inlet of the heating and converting means, means into which the products from said heating and converting means are discharged under reduced pressure, the said 40 second means being adapted to allow vaporization and separation of vapors, reflux condensate and residue, said second means being provided withmeans for separately withdrawing vapors, reflux condensate and residue and being also pro- 45 vided with cooling means in the top and heating means in the bottom thereof, a plurality of means for successively receiving vapors from said second means and also for receiving charging oil to cause the latter to flow in counter-current direc- 50 tion to said vapors and to be delivered through the above mentioned cooling meansilocated in said second means to said heating and converting means, means for supplying liquids from said second means to the inlet and outlet of said heat- 55 ing and converting means and to intermediate points thereof, means for discharging oil from an intermediate point of said heating and con, verting means into the stream of products passing from said heating and converting means to 60 said second means and separate distilling means connected to said second means for separately-receiving reflux condensate and residue from said second means. Y

WILLIAM L. GOMORY. 65