US1938836A - Method for hydrocarbon oil treatment - Google Patents

Description

Dec. 12, 1933. L. c. HUFF 33,836

METHOD FOR I IYDROCARBON OIL TREATMENT Original Filed March 50, 1925 Patented Dec. 12, 1933 l METHOD FOR HYDROCARBON OIL TREATMENT 1 Lyman C. .IHufl', Chicago, Ill., assignor to Universal Oil Products Company, Chicago, Ill.,a corporation of South Dakota Application March 30, 1925, Serial No. 19,245

. Re'newed October 22, 1929 5 Claims. (Cl. 19666) sion temperature and discharged into an enlarged chamber, wherev vapors are released, these vapors being dephlegmated and the reflux condensate returned and mixed with the oil being heated.

A substantial amount. of the heated oil discharging into the enlargedchamber will remain unvaporized. The oil and vapors under treatment are maintained under a substantial super-atmospheric pressure.

The vapors leaving the dephlegmator and the unvaporized residue from the enlarged chamber are taken off as separate products and mixed together while still under heat and pressure. This mixture is then cooled while under substantially the same pressure.

The invention' further resides in the idea of reheating the cooled mixture under pressure and thenreleasing the pressureand effecting distillation. The mixing of vapors and residue and the subsequent cooling of the mixture is done to preventexcessive losses of the lighter ends, as well as to improvelthe stability of the residuum which under the present invention will contain less settlings. There will be less pitch forming and coke-like particles suspended in the residuum,

able and marketable product which can be used for fuel. 1

, Thesingle figure in the drawing is a diagrammatic, side elevational view of the apparatus.

" Referring in detail to the drawing, '1 designates the inlet line for the charging stock, which inlet line is controlled by valve. 2 and discharges the raw oil into the closed coil 3.. The closed coil 3 discharges the oil'into the line 4 controlled by valves 5 and 6 and into the upper end of the 'dephlegmator 'l. The purpose of passing the oil through the closed coil 3 is to preheat it, as here-' which, of course, produces 'a' much more desircommunicating with line -12, in which maybe interposed the pump 13. This line 12 discharges the raw'oil and reflux condensate into the inlet side of the continuous heating coil '14, which may be mounted inthe side fired furnace 15 heated by means of the burners 16, the gases of combustion flowing downwardly countercurrent to the upward flow of the oil through the coils 14. The oil in-its'passage through the coil 14 will be heated to a conversion temperature and the heated oil discharged through the transfer line, 17 controlled by valve 18 to the upper end of the enlarged reaction chamber 19, which may be insulated as shown at 20, and which is preferably externally unheated. This reaction chamber 19 is shown in the present instance as .being disposed in a vertical plane, but it is understood, of course, that it may be disposed in any plane,for instance, a'horizontal. Suitable manhole plates are provided for cleaning. v The lighter fractions of the heated oil will sep- 7 arate from the heavier fractions in the chamber 19 in the form of vapors and pass on through vapor outlet pipe 21 controlled by valve 22, being introduced to the lower portion of the dephlegmator '7. dephlegmator, these vapors are subjected .to the bafiling action of baflies, pans or bubble trays superimposed in the interior thereof, and the vapors are alsophysically subjected to the cooling effect of the raw oil introduced through the line 4. This cooling and baffling will cause the heavier ends of the vapors to condense out, returning with the raw oil through the reflux leg 10, as heretofore explained. The vapors remaining uncondensedafter passing through the dephlegmator, pass out through the vapor outlet 23,- in which is interposed valve 24, pressure gauge 25 and pyrometer 26. The unvaporized residue is withdrawn from the reaction chamber 19 through the residue draw-offs 27 controlled by valves 28, discharging into the residue draw-off header 29, in which is interposed valve 30 and pyrometer posed the pressure gauge 37, and may be passed In their upper passage through the 80 through the line 38, the valve 39 being opened, to the cooling coil 40, mounted in the box 41, from which box the cooled product is withdrawn through the line 42 controlled by valve 43.

As another method of operation,.instead of cooling the product issuing from the'line 36, the valve 39 maybe closed and valve 44 in line 45 opened. The line 45'communicat'es by means of the line 46 and valve 47 with the heat interchanger 47'. The mixture passing through the heat interchanger is discharged through the line 48 controlled by valve 49, which line 48 communicates with the coolingcoil 50 mounted in box 51, from which it may be withdrawn through the j line 52 and discharged to storage, valve 53 being opened. f

Where it is desired to reheat the mixture to effect distillation thereof, the valve 53 is closed and the product issuing from pipe 52 is transferred to the line 54, in which line is interposed the valve 55' and pressure gauge 56. This line'54 also passes through the heatin'terchanger and discharges through the line 57 controlled by valve 58, being introduced to the fractionating tower 59. Steam may be introduced in the bottom of the fractionating tower to assist in the distillation and further heating of the mixture through the line 60 controlled by valve 61. 7 Where it is not necessary to preheat'the mixture at all, the valve 47 is closed and valve. 62 in connecting line 63 opened, causing the mixture to pass directly to the pipe 57 without passing through the preheater.

"Distillation is effected in the tower 59, the vapors passing off through the vapor outlet 64 controlled by valve 65 communicating with condenser 66in box 67, and the condensed product withdrawn through the line.68 controlled by valve 69'communicating with the receiver '70. The said receiver 70. may beequipped with the usual sightglass gauge 71, the gas relief line 72 controlled byvalve '73 and liquid draw-offline 74 controlled by valve '75. The unvaporized bottoms may be,

withdrawn from the tower 59 through the line 7-5 controlled by valve 77.

It is not thought that any extensive explanation of the operationneed be given in view of the detailed nature of'the foregoing description. I am aware that heretofore vapors and residue discharging from a still or enlarged chamber have mixed togethenbut I believe I am the first to combine the reflux principle with the idea of mixing the vapors and unvaporized residue with a consequent beneficial effect. The tower 59 isin reality a vaporizer and stripping column. The pressure is preferably reduced slightly on both the vapors and residue just prior to their mixing. As an illustration of the pressures which may be main* tained throughout the plant, thepressure on the pressure gauge 25 may register 200 pounds; the pressure on the gauge 37 may register 175 pounds;

' the. pressure on the gauge 56 may register 170 pounds, and the pressure on the gauge 56 may register 15 pounds. The oil passing through the heating coil 14 is heated to a temperature of say 750 to 950 F., more or less. Itis pointed out that a certain amount of oil is continuously charged sion temperature, discharging the into an enlarged chamber where heavy products are drawn off separately. In order to improve their quality and yet take advantage of the reflux principle in cracking the oil, it is advisable to bring the lighter ends and the heavier ends together while still under fairly high temperature and super-atmospheric pressure, mixing them thoroughly and cooling them under pressure before releasing the mixture from the system.

The arrangement shown also provides for cooling the mixture under pressure and heating it againbefore releasing it into the stripping column 59 for distilling the lighter gasoline ends.

I claim as my invention: 1. A method of hydrocarbon oil consisting in heating the oil to conversion,

a converheated oil substantial separation of lighter fractions in the form of vapors takes place, subjecting the vapors to dephlegmation, removing the uncondensed vapors after dephlegmation, returning and mixingreflux condensate from the dephlegmating zone with the oil being heated,.separately withdrawing the unvaporized residue from the enlarged chamber, maintaining a substantial superatmospheric pressure on the oil and vapors under treatment, mixing the vapors removed from the dephlegmating zone and heated residue from the enlarged chamber without substantially reducing the pressure and cooling the mixture while still under pressure.

2. A process of hydrocarbon oil conversion comprising maintaining a body of oil under crack: ing conditions of temperature and pressure, sub jecting vapors evolved from the oil to, dephlege mation, removing uncondensed vapors from the dephlegmating zone, uniting reflux condensate separated from the vapors during dephlegmation with the oil undergoing treatment in the process, separately withdrawing unvaporized residue from said body of oil, mixing uncondensed vapors removed after dephlegmation and heated residue from said body of oil While in a heated condi-: tion and under superatmospheric pressure, cooling the mixture while under pressure, thence admitting the mixture to a fractionating column wherein gasoline-like constituents only of the mixture are vaporized, maintaining a lower pres. sure in the fractionating column than main tained on said body, of 'oil, and recovering the gasoline-like constituents vaporized in said frace tionating column. I a

3. A method of cracking hydrocarbon oil which comprises heating the oil, to a conversion temperature in a hea ing zone, discharging the heated oil into a reaction zone wherein separation of vapors and unvaporized oil takes place, removing the vapors and subjecting the same to dephlegmation, separately removing unvaporized oil from said reaction zone, maintaining a superatmospheric pressure on the liquid and vaporsuna dergoing treatment, combining the dephlegmated vapors with the withdrawn unvaporized oil under pressure, reducing the pressure on the resultant mixture to efiect a partial vaporization thereof; and condensing the evolved vapors.

4. A method of cracking hydrocarbon oilwhich comprises heating the oil to a conversion tem perature in a heating zone, discharging the heat.- ed oil into a reaction zone wherein a separation of vapors and liquid oil takes place, removing the vapors and subjecting the same to dephlegmation to condense the, heaver insufiiciently cracked it at o u n n he o d nsed heav er raced oil under conditions permitting vaporization, condensing a portion of the vapors evolved, withdrawing a stream of oil from said body, discharging said stream of oil without substantial loss of heat into a separation zone in intimate contact with the uncondensed portion of said vapor, and fractionating the mixture in said separation zone.

LYMAN C. HUFF.

Images