US2083212A - Treatment of hydrocarbon oils - Google Patents

Description

June 8, 1937. J. G...ALT HER I TREATMENT OF HYDROGARBON OILS Original Filed Feb. 16, 1931 2 Sheets-Sheet 1 mVUQKRB for:

June 8, 1937. J. G. ALTi-IER TREATMENT OF HYDROOARBON OILS Original Filed Feb. 16, 1931 2 Sheets-Sheet 2 Patented June 8, 1937 V PATENT 'OFFIC TREATMENT OF HYDROCARBON OILS Joseph G. Alther, Chicago, Ill., assignor, by mesne assignments, to Universal Oil Products Company, Chicago, 111., a corporation of Delaware Application February 16, 1931, Serial No. 516,020

Renewed May 20, 1935 1 Claim.

This invention relates to the treatment of 'hydrocarbon oils, and refers more particularly to the simultaneous treatment and conversion of the unvaporized residual liquid product and thegases resulting fromthe pyrolysis or cracking of hydrocarbon oils.

In the treatment of hydrocarbon oils primarily to convert the same into lower boiling products less valuable by-products are obtained, such as a relatively heavy unvaporized oil and/or a carbonaceous residue and gases, all of which are generally used for fuel purposes. It is among the I objects of the present invention to further convert. the unvaporlzed liquid residue and the gases, into more valuable low boiling products.

Inone of its specific embodiments the invention provides a process which comprises subjecting heavy hydrocarbon oils to treatment at elevated temperatures and pressures while simultaneously subjecting the gaseousproducts of the cracking process mixed with similar extraneous gases to a similar treatment at elevated temperatures and pressures, combining the liquid and gaseous streams so as to produce an intimate mixture thereof, introducing the mixture of hydrocarbon liquids, vapors and gases into a large reaction zone wherein separation of vapors and liquids is effected, passing the vapors from the reaction zone preferably through a reheating and reconversion zone prior to admission to primary iractionating devices for the production of vapors of desired boiling point range which are cooled, condensed and collected, preferably passing heavy liquids from the auxiliary vaporizing a chamber to the treating zone for further conversion and returning reflux condensates along with preheated raw oil from the auxiliary fractionator to the primary fractionator. v

To enable an accurate description of a particular operation of many falling within the scope of the invention the attached drawings are provided which show diagrammatically in Fig. 1 an arrangement of apparatus and equipment which may be employed.

Heavy hydrocarbon oil charging stocks typified by the residue produced in the topping of crudes or heavy hydrocarbon oil mixtures from any source may be taken by pump 3 from line I, containing valve 2, and discharged through line 4, containing valve 5, to auxiliary fractlonator 6 wherein heat exchange is effected and the preheated raw oil mixed with reflux condensates passed out through line 1 containing valve 8 to pump 9. The vapors from the auxiliary fractionato'r pass through line 66, containing valve 61, to auxiliary condenser 68 in which cooling is eifected with condensation of liquid products, the cooled products passing to line 69, containing valve 10, to receiver H which is provided with line I2, containing valve I3, for the release of 5 fixed gases and line it, containing valve. 15, for the withdrawal of liquid of approximatelydesired boiling point range.

Pump 9 discharges through line "I, containing valve H, into primary fractionator l2, in which' the vapors from the conversion zone are undergoing fractionation, the incoming oil being further preheated and partially fractionated and combined with reflux condensates leaving through line l3, containing valve M, to pump l5. Pump l5 discharges through line l6 and valve l'l into heating element l8 disposed in furnace l9. During passage through the heating element temperature and pressure conditions are attained sufilcient to insure desired conversions and the 2 heated materials leave through line 20, containing valve 2 I, to enter mixing device 23 which may be of types more fully described with reference to Figs. 2 and 3. Preheated gas mixtures are introduced to the mixer from line 65, as will be later more fully described. In mixer 23 an extremely intimate commingling of products is effected, the mixture passing through line 24, containing valve 25, to enlarged chamber 26 which is provided to allow time for the completion of conversion reactions.

Chamber 26 is preferably thoroughly insulated to conserve heat. Temperatures employed at the outlet of the heating element are those characteristic of the temperatures employed in com- 35 mercial cracking operations and may be of the order of 750 to 1000 F., more or less, and pressures employed during the reaction period ensuing in chamber 26 may be high'superatmospheric up to 500 pounds per squareinch or higher. The

vapors from the reaction chamber pass through line 21 containing valve 28 either directly through valve 28 to primary fractionator l2, which typifies any suitable arrangement of equipment for separating low boiling liquids of desired characteristics or preferably through line 16, containing valve 11, to supplementary heating element 18 disposed in furnace 19, the reheated vapors passing through line 80, containing valve 81 back tollne 28 and thence to fractionator l2 as before, this fractionator receiving from line 53 a. certain portion of the end product liquids to control boiling point range, as will be later more fully described,- and from line H! a mixture of preheated raw oil and certain intermediate fractions from 55 the bottoms produced in reaction chamber 25. The pressures employed in fractionator l2 are 4 preferably of the same order as those employed in the conversion zone.

5 Heavy liquid-accumulations in reaction chamber 26 pass through line 29 and valve 30, preferably with pressure reduction to approximately atmospheric or relatively low superatmospheric pressure to auxiliary vaporizing chamber 3| in which evolution of light fractions is permitted, these passing through line 32, containing valve 33, to auxiliary fractionator 6. Chamber 3| is also provided with line 34, containing valve 35, as an outlet for liquid residues, line 34 branching into line 38, containing valve 39, which permits withdrawal of heavy liquids from the process and line 34', containing valve 35', leading to pump 36' which discharges into line 36, containing valve 31, leading to line |B,thus enabling the rctreatment and reconversion of all or a portion of the heavy liquids from the chamber in the treating zone.

' Vapors from iractionator l2 pass through line 40, containing valve 4|, and through condenser 42 which eifects partial condensation and cooling, the cooled products passing through line 43. containing valve 44, to receiver 45. Line 50, containing valve 5|, leading to pump 52 permits the utilization of suitable portions of the end product 80 liquids for the control of boiling point range of vapors, these liquid portions being discharged through line 53, containing valve 54, to fractionator |2 as already indicated.

Receiver 45 is also provided with line 48, con- 35 taining valve 49, for the withdrawal of low boiling liquid products of the process and line 48,

containing valve 41, to permit the release of 'excess accumulations of fixed gases. Branch line 55, containing valve 56, leads from line 48 to pump 51, which also receives outside hydrocarbon gases from line 58, containing valve 59. v

As examples of gas mixtures extraneous to the process which may be employed may be mentioned cracked gases from other units similar to the one described, or other types of cracking units, natural gas, petroleum refinery gases, coal gas, oil gas, water gas, etcetera. Pump 5'! discharges gas mixtures through line 60, containing valve 5|, into and through heating element 52 disposed in furnace 53,. the gases being heated to suitable temperatures for their, subsequent reactions in mixer 23 and the reaction chamber following, being introduced'into mixer 23 through line 65 and valve 64, as already indicated. Temperatures to which the gas mixtures may be pre-' heated may vary with the composition of the mixtures employed, the nature of the raw oil charging stock and the conditions obtaining in the conversion zone, but will generally be of the order of from 800 to 1200 F., more or less. The reactions induced supplementary to theordinary cracking reactions by the introduction of the may be utilized .in an apparatus such as that above described for intimately oommingling the vapors and the oil from the two heating elements. Oil from the heating element I8 is introduced to the mixing device through line 20 and I is discharged from cup or deflector A into the uppermost of a series of rapidly revolving discs B, C and D. .Discs B, C and D are mounted on shaft E, supported at one end by an alignment and thrust bearing F, which may, if desired, be cooled in any suitable manner (not shown) for example, by circulating cold oil therethrough. Shaft E is packed at G, where it passes through the outer shell H of the mixing device, and the stufiing box I may be cooled by radiating fins J, or in any other suitable manner. Shaft E and the attached discs are rapidly rotated by any suitable means (not shown), such as, for example, anelectric motor, a steam driven turbine, or any other motivating means. Gases from heating element 62 introduced to the mixing device through line 85, pass upward around the rapidly revolving discs D, C and B, coming in contact with the liquid introduced through line 20, which is substantially atomized and vaporized by impingement upon the rapidly revolving discs and hurled by the centrifugal force of the revolving discs into the stream of gases passing through the apparatus. The vapors, gases andatomized liquid thus intimately commihg'ledin the apparatus pass through line 24 to reaction chamber 26.

Fig. 3 of the attached drawings illustrates another suitable form of mixing device which may be employed for injecting the oil from heating element l8 into the stream of gases from heating element 62. The heated gases are introduced through line 65 and their velocity is greatly increased by means of nozzle K as they pass into line 24. Heated oil from heating element I8, introduced through line 20 to the zone L, surrounding nozzle K, is impelled by the high velocity of the gases passing from nozzle K through chamber M to line 24 through the orifice N into the stream of gases and is intimately commingled with said stream of gases passing therewith through line 24 to reaction chamber 26.

The descriptions given with reference to the three figures are illustrative of methods and means which may be employed within the scope of the invention, but are not to be construed in a limiting sense as many other types of apparatus may be employed without departing therefrom. As examples of the results obtainable by the operation of my invention, a Mid-Continent 24-26 A. P. I. gravity fuel oil is considered as charging stock. When the gas is not returned to the process, approximately 50% of gasoline of high anti-knock quality may be produced from this charging stock with a yield of approximately 35% of fuel residue, which is fluid when heated, and approximately 400 cubic feet of gas per barrel of charge. By returning the gas to the system and treating in the manner described, one may obtain under the same conditions of treatment approximately 55% of gasoline, the same quality of fuel oil residue, and the gas produced is reduced to approximately 250 cubic feet per barrel of ra oil.

Conditions of treatment in the operation herein considered are a transfer temperature of the oil leaving the heating element of approximately -900 F., a pressure on the heating element and reaction chamber of approximately 250 pounds per square inch, approximately pounds per square inch pressure on the vaporizing chamber and equalized pressure therewith on the fractionator. condenser and receiver. The tempera- 'ture to which the gas is heated is approximately 1000 F. to which approximate temperature the vapors emergent from reheating element 18 are also heated.

In the treatment of a 40-42" A. P. I. gravity Pennsylvania crude oil distillate, one may obtain -a yield 01' 65% .01 gasoline having an anti-knock value of approximately 55% benzcl equivalent, that is, equal to a mixture of Pennsylvania straight run gasoline and benzol containing 50%. of the latter, approximately 20% of i'uel oil residue and approximately 400 cubic feet oigas per barrel of raw oil.

I claim as my invention:

A process for crachng hydrocarbon oil and for conjcintly converting the residue and the incondensible gases of the cracking process into low boiling oils, which comprises maintaining hydrocarbon oil under cracking conditions of temperature and superatmospheric pressure in a reaction zone, separately removing from the reaction zone unvaporized oil and a mixture of vapors and incondensible gases, heating said mixture to vapor phase cracking temperature and then dephlegmating the mixture to condense insufliciently cracked fractions thereof as reflux condensate, flash distilling the withdrawn unvaporized'oil by pressure reduction thereby forming residue,

combining such residue and the reflux condensate -with charging oil for the cracking process and passing the commingled oils in a restricted stream through a heating zone, heating the commingled oils to cracking temperature under superatmospheric pressure in the heating zone and then discharging thesame into said reaction zone, further cooling the dephlegmated mixtureof vapors and gases to condense the vapors out of the gases and separating the resultant condensate from the gases, heating a substantial portion of the separated'gases to reaction temperature and commingling the same with the heated oils discharged from the heating zone into the reaction zone to react with the heated residue in the reaction zone. a

- JOSEPH G. ALTHER.

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