US1896226A - Process of cracking hydrocarbons - Google Patents

Description

Feb. 7, 1933. EGLOFF PROCESS OF CRACKING HYDROCARBONS Filed Dec. 21 1925 wag/.1:

Patented Feb. 7, 1933 u rrED STATES.

PATENT orrlcs GUSTAV nenorr, or CHICAGO, ILLINOIS, ASSIGNOR, T UNivERsAL OIL rnonuc'rs COMPANY, OF CHICAGO, ILLINOIS,'A CORPORATION OF SOUTH DAKOTA rnocnss or cnacxme n nnocaanoivs' Application filed December 21, 1925. Serial No. 76,636.

This invention relates to improvements in process of cracking hydrocarbons, and in general refers to a process in which the oil after having been subjected to crackingconditions of temperature and pressure so as to substantially vaporize the oil, the vapors are further superheated under cracking conditions of pressure to producea substantial yield of aromatic hydrocarbons therefrom, and so called fixed. gases high in-their content of v boiling point aromatic hydrocarbons.

.Aromatics of the above character are now commercially produced. very largely from the distillation of coal, but'it is the essence of the present invention to produce them from the cracking of petroleum oil, in a more practical and efiicient manner than heretofore attempted.

In order to more clearly understand the invention, I have shown the accompanying drawing, which is a more orless diagram.- matic side elevational view of an apparatus in which the invention may be carried out.

Referring to the drawing, 1 designates a furnace in which is mounted the heating tube 2 connected at its inlet side to the raw oil pump 3,and.at its outlet side through the transfer line 4 having throttle valve 5 to an enlarged expansion tank or chamber 6. This tank or chamber may be provided with a residuum drawolf 7 controlled by throttle valve 8 and with vapor-outlet line 9. con-' trolled by throttle valve 10. The vaporpipe 9 is in turn connected to a second heating tube 12 located in the furnace 13. The delivery end of this coil is connected through transfer line 14 to a second expansion chamber 15 which may, if desired, e mounted in a suitable setting 16. The chamber 15 may be provided with residuum drawofi 17 controlled by throttlevalve 18 and with vapor pipe 19 having throttle valve 20 leading into the lower end of the depblegmator 21. The arrangement is such that vapors can pass into the depblegmator, but the reflux condensate cannot fall down throughthe pipe 19 into the chamber 15. The depblegmator may be provided with a plurality of baflles 22 and vapor outlet pipe 23 having throttle valve 24, which pipe 23 leads to the WatercOndenser 2'5 and thence to receiver 26 between which is interposed. throttle valve 27. The receiver 26 is" equipped with gas outlet pipe 28 controlled by throttle valve 29. The'pipe 28 may be connected with suitable gas holder not shown. The receiver 26 is also equipped with liquid drawofi pipe 30 controlled by throttle-valve 31.

The reflux condensate from the lower portion of the dephlegmator 21 is drawn oif .through the pipe 32 in which is preferably interposed a pump 33 having at either side thereof throttle valves 34 and 35. The reflux I condensate may be pumped from line 32 through the extension 36 to the vapor pipe 9, or by closing the throttle valve 31 and openin the throttle valve 38 in the branch 40 the re ux condensate may be delivered to storage or elsewhere, as desired. However, in carrying out my invention, I find it will be advantageous in some cases at least, to return the reflux condensate to the line 9 where it is-mixed with the vaporsv in said line.

he raw oil in a preheated condition, may be fed from storage tank '41 by means of pump 42 and pipe 43 to the closed coil 44 seated in the depblegmator, and thence through pipe 45 to the raw oil pump 3. If desired, the oil may be partially or wholly by-passed through the line 46 and throttle valve 47 In the event the line 46 is used, the valve 48 in the line 45 may be wholly or partially closed. A check valve 49 :is interposed in the line 36, andso positioned that it only sulated, or may be externally and independently heated, the tank 6 being heated through a suitable furnace, not shown, if such heating is there desired.

One method of carrying out the invention may be described as follows:

Gas oil of 32 Baum gravity from the Kansas field, may be fed through the heating coil 2 where it is heated to a transfer temperature of say 900 F. while under say 1000 pounds more or less pressure. more or less liquid-vaporphase is passed to 'the expansion chamber 6, where it may be maintained at say 400 pounds pressure, more or less, the vapors leaving the expansion chamber at say 875 F. The vapors pass from the line 9 into the heating coil 12 where they may be heated to a vapor temperature of say 1200 F. while subjected to a pressure of 200 pounds. If the reflux is mixed with the vapors before entering the coil 12, the reflux will likewise be vaporized and heated to such temperature at such pressure. The superheated vapors then pass through line 14 into the expansion chamber 15 where the ressure may bev at 150 pounds through suitably controlled reducing valve 14 The vapors pass out through the vapor outlet 19 into the dephlegmator 21 where the heavier portions thereof are condensed and drawn out of the dephlegmator and either sent to storage as for example, the storage tank 41 or they may be mixedwith the vapors in the ipe 9. If desired, only a portion of the re ux condensate is passed to the pipe 9 while the other portion is drawn off elsewhere. This will permit V of controlling the relative proportion of reflux to the vapors in the pipe 9. The temperature of the dephlegmator may be so controlled either by the closed coil 44 herein described, or in any other suitable manner now well known in the art, so that they will leave the top of the dephlegmator at say 400 F., and thence pass into the water condenser 25 and thence to the receiver 26. By suitably controlling the valve 24, a pressure of say 125 pounds may be maintained-on the dephlegmator, and by controlling the valve 27, a pressure of 100 pounds may be maintained on the water condenser; by suitably controlling the valve in the receiver, a pressure of say pounds may be maintained on the receiver.

It is understood that it may be desirable in one method of operating the apparatus here shown, to accomplish certain desired results, to have the entire system under the same pressure of say 200 pounds more or less.

The oil in a for use in the so-called anti-knock motor fuels. It is well known to those skilled in the art that aromatic hydrocarbons are better anti-knock motor fuels than paraffine hydrocarbons. Furthermore, by means of this process not only is a high percentage of aromatic hydrocarbons formed, but also a much larger percentage of olefines and also diolefines. It is also well known, that these olefine hydrocarbons are highly desirable as anti-knock motor fuels.

I claim as my invention:

1. A continuous process for cracking hydrocarbons, comprising initially raising a hydrocarbon oil to a cracking temperature while under a superatmospheric pressure, removing from the hydrocarbon oil such vapors as are evolved therefrom, raising the temperature of all of such vapors, prior to condensation, substantially 300 F., above the temperature to which said hydrocarbon oil was initiallysubjected, thereafter subjecting such va orsto reflux condensation and uniting re ux condensate separated from the vapors with the vaporo'us constituents being evolved from said hydrocarbon oil without returning said reflux condensate to the oil from which the vapors are evolved.

2. A process for cracking hydrocarbon oil, comprising initially heating the oil to a cracking temperature under superatmospheric pressure, thereafter permitting the oil to By carrying out the invention in the manner hereinbefore described, I convert a substantial part of the original charging stock

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