US1658415A - Process for cracking petroleum oil - Google Patents

Description

menait Feb. 7, 192s.

UNITEDl STATES A 1,658,415 PATENT OFFICE.

i ROBERT T. Pontoon, or BOSTON, MASSACHUSETTS, AssIoNOR Toumvnasaz. OIL

PRODUCTS oomramr, or onIcAGO, ILLINOIS, a CORPORATION or SOUTH DAKOTA.

., PROCESS FOR` CRACKING- PETROLEUM OIL.

` Application nled December 20,1990. Serial No. 431,838.

This invention relates to improvements in process and for cracking petroleum oil and refers more particularly to that type .of

process in which the generated vapors are subjected to reflux condensing action and the reiiux condensate, i. e., the incompletely converted Oil constitutents subjected to further cracking reaction.

With certain types of petroleum oil, the

reflux condensate produced inthe cracking operation is more desirably subjected to further cracking reaction under different temperatures and presures than is the original oil. By means of the present process, this refiux condensate 'caribe separately cracked as part of a continuous process and under different. conditions of temperature and pressure than the raw oil. As a further feature of the invention, the generated vapors are 2 subjected to a4 double 'refi'ux condensing action in which the heaviest portions of the vapors are condensed and separately recracked while thev intermediate portion of the vapors, i. e., those lighter than the heaviest but not yet suiciently cracked and therefore heavier than the lightest, are separately condensed, subjected to further cracking under still different conditions ot temperature and-pressure.

In the drawing, the single figure shows a somewhat diagrammatic view partly in side elevation and 'partly .in vertical section of improved apparatus for carrying out my process.

Referring in detail to the drawing, A. B andv C designate three separate furnaces. In the furnace A is mounted a heatingcoil 1, as for example. a continuous coil of 2 to 6" pipe. This coil is fed from the charging pump 2, connected to the raw oil supplv by inlet line 3 and delivering the raw oil to the heatingelement through the feed line 4 having throttle valve 5. The discharge side of the coil is connected by transfer line 6 having throttle valve 7 to vapor chamber 8. This vapor chamber 8 is provided with liquid residue drawoff pipe 9 controlled by throttle valve 10.' It also has vapor 'outlet pipe 11 and downwardly inclined extension pipe 11 having throttle valve 12 and con'- nected to the lower side of the dephlegmator' 13'. The upper end of the dephlegmator 13 is connected by vapor pipe 14 having throttle valve 15 to a partial condenser or reflux condenser 16. The vapor space of this condenser is connected by a pipe 17 -having throttle valve 18 to iinal condenser coil 19 seated in water condenser 20. The \lower end of the coil 19 is connected to the upper part of receiver 21. This receiver 21 has li uid level gauge 22. liquid drawotf pipe 23, avin throttle valve 24 and gas outlet pipe 25, avingthrottle valve 26. v Referring back to the dephlegmator 13, to its lower end is connected a reflux condensate pipe 27, which leads to the inlet side of the heating coil 28 mounted in the furnace C. A throttle valve 29 is interposed in the line 27. There is likewise interposed in this line a pump 30 provided at either side with valves 31 and 32, whereby the refiux condensate may be pumped under increased pressure, if desired. A by-pass line 33 having athrottle valve 34 is provided for b vpassing the pump, if desired. The discharge side of the coil 28 is connected by transfer line 35 havin throttle valve 36 to vapor chamber 37. his vapor chamber 37 4is provided with liquid drawoif pipe 38 controlled by throttle valve 39. The upper end of the vapor chamber is connected by vapor pipe 40 and downwardly inclined pipe 41 having throttle valve 42, to the lower side of a ,dephlegmator 43.

is provided with vapor Outlet pipe 44 having throttle valve .45, which pipe 44 is connected to final condenser coil 46 seated in condenser box 47. The lower end of the coil is connected by pipe 48 having throttle valve 49 to the upper part of receiver 50. This receiver 50 has liquid drawoff pipe 51 con- This dephlegmator 43 trolled by throttle valve 52 and gas outlet y pipe 53 controlled by throttle valve 54.

Referringl back to the dephleginator 43, to its lower end is connected reiux return pipe 55 in which is interposed a pump 56 having at either side valves 57 and 58. The pump may be by-passed by pipe 59 having valve 60. This line 55 connects to extension 55 leading to the heating coil 61 seated in furnace B. This coil may be of the same construction as the other two. The .discharge side of this coil is connected by transfer line 63 having throttle valve 64 to an expansion or vapor chamber 65. This eX- pansion chamber l65 has a liquid drawoi ipe 66 controlled by throttle valve 67. It 1s also provided with the vapor outlet pipe valve 97 interposed in the end of the pipev The upper end of the dephlegmator is con nected by vapor pipe 72 having throttle valve 73 to condenser coil V74 seated in condenser box 75. The lower end of the coil is connected by pipe 76 having throttle valve 77 to the top of -receiver 78. This receiver 78 has vliquid drawof'f pipe 79 controlled by throttle valve 80 and gas outlet throttle valve 82.

The lower end of the dephlegmator 71 1s connected by reflux condensate p1pe 83 having throttle valve 84 to a second return pipe 85 leading back to the pipe 55', whereby 1t may be returned to the heating coil 61. 'l `he line 83 is also provided with the branch plpe 86 having throttle valve 87 connected to any suitable receptacle (not shown), whereby the reflux condensate may be led elsewhere than delivered to the coil 61. In this case a. valve 88 in the line 85 can be closed and valves 84 and 87 regulated. 1n the pi e 85 1s interposed a pump 89 having at e1t er side, valves 90 and 91, whereby the reflux condensate may be returned to the pipe 55 under pressure. This pump may be by-passed by means of pipe 81 controlled by the pipe 92 having throttle valve 93. A

throttle valve 94 is interposed in the pipe 55.l l have heretofore stated that the rellux condensate from the pipe 55 may be de' livered to the pipe 55,. It also may be delivered elsewhere, to-wit:-to a suitable receptacle, (not shown), by means of branch 95 having throttle valve 96. In this case the 55 will be closed. y

Referring back to the partial condenser 16,

to its lower side is 'connected condensate return pipe 98. In this pipe line 98 is ,interposed a pump 99 having suitable valves at either side thereof and `Aalso provided with the by-pass line 100 having valve 101.` The lower end of the pi e 98 is connected as shown at 102 to the line 55', provided with control valve 103. The reflux condensate instead of being returned to the pipe 55 may be delivered to a suitable receptacle (not shown) by means ofthe branch 104 having throttle valve 105.V

The process may be operated as follows: Raw oil, as for example, petroleum -fuel oil, may be fed continuously to the heating tubes 1 where it is heated to a temperature of say, 750 degrees F. and while lin substantially liquid phase passed to the vapor chamber 8 and thence to the first reflux condenser. The uncondensed portions will pass to the partial condenser 16 and the still uncondensed ortions will pass to the condenser 19 and thence to the receiver 21. All of the elements so far referred to may be maintained under a pressure of say, 150 pounds. The reflux condensate from the dephlegmator 13 may be astenia pumped by means of the pump 30 to the second heating coil 28 and there subjected to a temperature 'of say, 800 degrees F., passingthence -to the vapor chamber and thence to the dephle ator 43.. The uncondensed the top of receiver 50. This part of the sy'stem from the coil 28 to receiver 50 may be means of the pump 56 to the lines 55 and 55 and thence to the heating coils 61 seated in the furnace B. Here the reflux condensate will be heated to a temperatureyof say, 850 degrees F. The reflux condensate will thence pass into the chamber 65 and the vapors therefrom into the dephlegmator 7.1. The uncondensed portions will pass out of the dephlegmator into the condenser 74 and thence to the receiver 78. The heating tubes 61 and associated mechanism may be maintained under a pressure of say, 250 pounds. The reflux condensate from the dephlegmator 71 may be returned by pump 89 to the pipe 55 and thence through the tubes 61.

vThe reflux condensate fromthe second re`i 70.*'. 'portions wil pass out'mofY the top of the dephlegmator 43 into the coil 46 and thence toy it will be seen that the raw oil and the diii'erent cuts of reflux condensate are all treated under different pressures and temperatures.

The process may be carried out exactly in' the manner above described except that the reflux condensate from the artial condenser 16 may be by-passed throug the line 104 or the reflux condensate from the dephlegmator 71 may be by-passed through the line 86 and may be recracked in a system separate if desired, or the partial condenser may be left in the system in the manner as described and only the reflux condensate from the dephlegmator 71 drawn ofl through the line 86.

The process may be operated in the manner rst above described, except thatthe oil 'in the rst heating coil may be heated to a temperature of say, 650 degrees F. and Sub' '-jected to a pressure of 100 pounds; the oil in the second heating coil, to-wit, in the furnace C heated to a temperature of 750 degrees F. and subjected to a pressure of 150 pounds while the reflux condensate passed through the furnace B may be heated to a temperature of 750 degrees F. and subjected to a pressure of 200 pounds.-

The process may also be operated by maintaining a pressure of say, 150 poundsl on the heating coil 1; a reduced pressure, as for example, 75 pounds, on its associated condenser and dephlegmator and partial condenser and 50 pounds on the final condenser 19 and receiver 21, the oil being' heated to a temperature of say, 680 degrees F. The pressure ico on the oil in the heating coil in the furnace C may be 200 pounds, at a temperature of 720 degrees F.; the pressure on the associated vapor chamber and final condenser and receiver reduced say, to pounds. The oil in the heatin coil 61 may be heated to a temperature of degrees F., subjected to a pressure of 250 pounds, while the associated vapor chamber and dephlegmator may be maintained under a ressure of say, 100 pounds and the associated iinal condenser and receiver at 50 pounds.

The process may also be carried out in the manner last described except that the vapor chamber may be maintained under the same pressure as the oil in the heating tubes While the dephlegmator may be maintained at atmospheric pressure.

I claim as my invention:

l. A process of cracking oil, which con- M sists in passing the oil through a heating coil wherein it is subj ected to crackin(Sr conditions of heat and pressure, in discharging the oil from said coil into a vapor chamber, in passing the vapors from said vapor chamber through successive dephlegmators, in passing the reflux condensate from each of said dephlegmators under applied pressure to independent heating zones and in subjecting the reflux condensate passed to each of said independent heating zones to higher temperatures than the tem eratures to which the oil is subjected in said heating coil.

2.' A process of cracking oil, which consists in passing the oil through a heating zone wherein it is subjected to cracking conditions of heat and pressure, in dephlegmating the vapors produced from said heating zone in successive dephlegmators, in passing the reflux condensate from each of said dephlegmators under an applied pressure to independent heating zones in subjecting the reflux condensate in each of said independent heating zones to a higher temperature than that to which the oil is subjected in said rst named heating zone, in condensing the vapors issuing from the last of said dephlegrnators, and in collecting the resulting distillate.

3. A continuous process for cracking hydrocarbon oil, consisting in initiall subjecting the oil to cracking conditions o heat and pressure to cause substantial conversion thereof, in subjecting the vapors evolved `from the oil to primary and secondary dephlegmatin actions, in separately subjecting the re uxcondensates resulting from said primary and secondar dephlegmating actions to independent crac ing reactions at temperatures substantially above the temperature to which the oil was initially subjected.

ROBERT T. PoLLocK.

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