US2096204A - Treatment of hydrocarbon oils - Google Patents

Description

Oct. 19, 1937.

J. DELATTRE-SEGUY TREATMENT oF HYDRocARoN oILs Original Filed Feb. 11, 1931 INVENTOR F N m .T n

Patented Oct. 19, 1937 UNITED sTA'rEsl TREATMENT OF HYDROCARBON OILS Jean Delattre-Seguy, Chicago, Ill., assigner,

mesne assignments, to Universal Oil Products Company, Chicago, Ill., a corporation of Dela- Ware Application February 11, 1931, Serial No. 514,941 Renewed May 8, 1934 6 Claims.

The invention relates to the treatment of hydrocarbon oils and refers more particularly to the conversion of hydrocarbon oils of a relatively high boiling range into products of a more valuable character.

More specifically, the invention contemplates the utilization of hydrogenatingreactions in con. junction with a cracking process, the heavier products from cracking reactions being subsequently hydrogenated and some of the heavier' products from the .hydrogenating zone being. returned to a point in the cracking reaction zone to arrest the progress of thecracking reaction by causing a. suitable temperature drop, the hydrogenated fractions themselves in turn being suiciently heated thereby to insure later substantial removal of gasoline fractions.

In a preferred and speciflc embodiment of the process of the invention relatively heavy hydrocarbon oils are pumped under pressure through a heating element wherein they receive heat to initiate desired reactions and the heated products then pass through two reaction zonesin series. Prior to entering the second reaction zone the products are cooled, either by the admission of relatively cooler intermediate products and/or residue from an auxiliary hydrogenating unit or by the admission of raw oil charging stock, or both. The vapors from the second reaction zone pass through suitable fractionating devices from which vapors of desired boiling point range are removed, condensed and collected and unvaporized reflux condensates are returned for further treatment along With the raw oil.A Suitable auxiliary means are utilized to control the boiling point range of the hydrocarbon vapor mixture leaving the last fractionator. The non-vaporized portions of the cracking reaction products separating as heavy liquids in the secondary reaction zone are then brought to suitable temperatures either by heating or cooling, and are passed to an arrangement of reaction chambers into `which hydrogen or hydrogen-containing gases are admitted to eiiect hydrogenating reactions, suitable catalysts being present therein to reduce the time factor and to facilitate hydrogenation. The hydrogenating chambers may be employed in series ror in parallel and the hydrogen employed therein may bev suitably preheated if desired. Vapors from the `hydrogenating chambers, preferably after substantial pressure reduction, pass to a fractionating device in which partial separation of the fractions boiling within a. range suitable for gasoline is effected, these vapors being condensed and collected; a. suitable portion of the of the fractionator.

condensate being employed to control the boiling point of the hydrocarbons issuing from the top The liquid reiiux condensates from the fractionator, owing to the comparatively low temperature of the entering vapors, 5 due both to the relatively low temperatures employed in the hydrogenation chambers and the subsequent pressure reduction, contain material amounts of hydrocarbons boiling within the motor fuel range. These reux condensates are pumped back into the line between the two reaction chambers of the cracking unit, wherein they cool the cracking reaction products to temperatures suillcient to arrest undesirable side reactions and are in turn heated to a temperature which insures effective removal of their gasoline fractions in the fractionating devices of the cracking unit.

As an example of the operation of the process of the present invention the attached diagrammatic drawing which forms part of the present 20 specification shows one form of an apparatus that may be employed. Oil to be treated which may be typified by a crude petroleum from which gasoline fractionshave been removed by wellknown distillation methods is pumped by pump 3 from line l controlled by valve 2. By a suitable manipulation of valves 5, 1, 1 and 9' in line 4, t and 8 the charge may be proportioned among three points of admission. 'Through line 4 controlled by valve 5 it may be admitted at some suitable level in a primary fractionator 423 receiving the vapors from the cracking unit. When allowed to iiow through line 8' by opening valve 9 it meets the products of cracking at a stage prior to Vtheir admission tol chamber 20 in which the 'final reactions of decomposition or recomposition are controlled at" some predetermined point. When allowed to now through valve 1' and intol line 8 it mixes therein with reflux condensate from fractionator 23 which-is being returned to heating element 9 for further heating and conversion, pump 96 taking suction through line 93 with suitablesetting of valves 94', 95" and'98. A portion of the reux condensate may be removed through line 91 controlled by valve 98. Suitable pressures and temperatures are maintained during the passage of the combined feed from line 8 through heating element 9 to effect a certain portion of the desired conversion. In some instances further conversion is allowed .to take place without further addition ofA heat in a. chamberv which is typified by reaction chamber l2 through which the products enter and leave through lines l0, valves il and lines l5 and valves I4 respectively. In other instances it may be so ment 9 traversethe by-pass line I3 containing valve I4, enter line I5 and pass through valve I5 and line I1 into chamber 20. In the passage of the reaction products through line I1 they are controllably cooled by either the relatively heavy products from the bottom of the fractionator in the hydrogenation unit or the raw oil feed as previously described. Provision is also shown in line I8 controlled by valve I9 whereby the relatively heavy products from the hydrogenating unit` may be admitted at some level in the chamber instead of being admitted into line I1. The vapors from chamber 20 pass through line 2| controlled by valve 22 into fractionator 23 and the vapors from fractonator 23 pass through line 24 controlled vby valve 25 into fractionator 26 in series. The final product of gasoline boiling point range from the cracking unit passes through line 21 controlled by valve 28 to condenser 29 thence to y line 30 controlled by valve 3| to receiver 32, fixed gases' and vapors being released through line 33 controlled by valve 34 and the liquid of desired boiling point range being similarly released through line 35 controlled by valve 38. For accurate control of the boiling point range of the vapors leaving fractionator 26 a certain portion of the liquid products from receiver 32 is pumped controllably by pump 99 from line |00 and valve |0| through line |02' and valve |02 to the top of fractionator 25. For partial control of the boiling point range of the vapors leaving fractionator 23, pump |08 is shown in position to pump the bottoms from fractionator 2 5 through line |03, valve |04 and line |05 controlled by valve |01 thence on the discharge side through line ||0 controlled by valve |09 to the top of fractionator 23. The relatively heavy bottoms fron chamber 20 pass through line 31 and either thro `h line 4|v controlled by valve 39 or to pump 4|' through valve 38, the pump serving to increase pressure at subsequent .points inthe hydrogenation unit when found desirable. From linel 4| the evaporator bottoms are preferably passed-through valve 42 vto heating element 45 suitably disposed in furnace B wherein they are controllably heated to a predetermined temperature found most suitable to their subsequent hydrogenation. By ,theiuse of valve 43A a portion or all of the evaporator bottoms may be diverted around heating element 45 and a convenient con,

trol of temperature is at times thus eiected. From valves 43 or 44 the evaporator bottoms pas to hydrogenating chambers 41 and 41'. By suitable manipulation of valves 48, 20 and 89 in lines 48, 49, 59 and 88 the hydrogenating chambers 41 and 41' which typify any number of such chambers may be used either in series or in parallel, with regard to the vaporous products. By the use of line 5| containing valve 52 the liquid portions of the oils undergoing treatment in the hydrogenating chambers may be transferred. 'Ijhe hydrogenating chambers operate under conditions of temperature and pressure found most suitable to effect desired reactions and `preferably contain catalytic material typied by metals or their oxides alone or in combination which may be deposited upon. inert substances or may be maintained in suspension by means of vigorous mechanical agitation. 'I'he hydrogen necessary for the desired conversions is-taken from line 55 through valve 56 by pump 51 and preferably pre-l heated in heating element 59 disposed in furnace C with valves 58 and 60 open or a certain amount found best to omit the reaction chamber in which A case the products produced by the heating eleto storage disposed of through line mented by may be diverted around by the use of line 62 containing valve6|, a convenent method of control being thus provided. The hydrogen then at suitable temperature passes through line 63 and valve 54. into line 64' which. is manifolded so that hydrogen necessary lfor the desired reactions may be introduced to the hydrogenating chambers through lines typified by 53 and 63' containing valves 85 and 65' respectively. Means are shown in' lines 53 and 53' controlled by valves 54 and 54 respectively for discharge of spent catalytic materials from thelhy-f droge ating chambers. Vapors from the hydrogenat ng chamber pass through lines 56 controlled by valves 51 and 12 to fractionator -13 wherein hydrocarbons of boiling point range suitable for use as motor fuel are separated and passed through line 14 controlled by valve 15 to condenser 15, the condensed products along with uncondensible gases passing through line 11 controlledby valve 18 into receiver 19. Fixed gases 80 controlled by valve 8| and the mixture of liquid products suitable for use as gasoline similarly 82 controlled by valve 83. For accurate control of the boiling point range of the vapors issuing from fractionator'13 pump ||3 may draw a certain portion of the liquid end products through line and valve ||2 and discharge them at ator 13. The bottoms from fractionator 13 constituting reflux condensate from the hydrogenating vunit pass through line 84 controlled by valve 85 to pump 86 which discharges into line 81. Likewise, hydrogenated vapors from the chambers- 41 and 41 may pass in whole or in part through line 10 controlled by'valve 1| into line 81.

From this line the reflux condensate may be re-h turned as previously indicated to a point inthe cracking unit by `pump 93 which discharges through line 94 controlled by valve 95 either alone or in admixture with unvaporized oil from hydrogenating chamber 41' which may be taken by pump 90 to l-in`e and valve 89 from line 9| controlled by valve 92 into lthe line 81 and thence to pump 93 and line 94.

It will be obvious fromthe foregoing description that the process of the present invention comprises some very desirable features. The ordinary yield' o f cracked products of boiling point range suitable for motor fuel has` been aug'- the provision of a more or less distinct hydrogenating unit which can be employed as a balance wheel in effecting desired conversions over a wide range. The cracking unit and t the hydrogenatingl unitareY shown not only in:

chemical but. in physical interrelation, particularly with regard to heat transfer, and means have been disclosed for producing several types of end products for use as motor fuel. Pressures employed in the cracking reaction shown may be of the order of from 100 to 400 lbs. per sq. in. more or less, ceeding points in the units or may be equalized with respect to each other and temperatures employed in the cracking reaction vary from 850 to 950 F. approximately, these conditions together with the rate of feed which` controls the time factor being varied to suit the characteristics of the oil, being treated. f The pressures employed in the hydrogenating zone are in general higher than those employed in the cracking zone and may be as high as 3000 lbs. per sq. in. The temperature employed in the hydrogenating reaction are somel what lower than those employed in the cracking the heating` element 59 the top of fraction-v they may be differential at sucy may be removed to suitable storage through line 'used for cooling reactions and may be of the order of 750 to 375 F. more or less. Temperatures employed may, however, vary over a wide range fromy 600 to 1200 F. and pressures up to very high superatmospheric may be used. The catalysts employed in the hydrogenating chambers may be variously nely divided metals or their oxides alone or in combination as, for example, iron, nickel, cobalt, molybdenum, chromium, vanadium, etc. or mitxures of the same as well as oxides and other compounds may be employed.

As an example of an operation falling within the scope of the present invention a 25 gravity topped crude is fed to the cracking unit, 50% of the feed being sent to the fractionator, 25% between the reaction chambers and 25% fed direct to the heating element. Pressure maintained on the rst of small reaction chambers of the series is 200 lbs. per sq. in. and the temperature at the ex-it of the heating element 940 to 945 F. After passing through the small reaction chamber the reflux of raw oil and products from the hydrogenating zone lowers the temperature to 850 F. There may be produced continuously in the cracking unit to which 1000 bbls. per day of raw oil is fed, '550 bbls. of gasoline of approximately 425 F. end point, 100 bbls. of intermediate oils suitable for reprocessing, 250 bbls. of residual oil charged to the hydrogenating unit and an equivalent loss of 10% in fixed gases. 'Ihe 250 bbls. of residual oil which has a gravity of approximately 10 A. P. I. is treated in the hydrogenators at a pressure of approximately 2000 lbs'. per sq. in. and temperatures of approximately 750 F. in the presence of suitable catalysts producing an equal number of barrels of a synthetic crude of 35 gravity containing 40% of hydrocarbons of The vapors pass directly to the fractionator 13'. Owing, however, to the lower temperatures e ployed and the additional loss in heat due to the release in pressure at the fractionator from a portion of the hydrogenating equipment only 30% of the gasoline boiling point hydrocarbons is evolved from the fractionator. The bottoms from this fractionator are then pumped into the stream of Vproducts issuing from the smaller reaction chamber of the cracking unit wherein they received sulcient heat to enable subsequent effective removal of hydrocarbons of gasoline boiling point. There may be thus produced an overall yield of of hydrocarbons of gasoline boiling point range without the production of appreciable quantities of coke and with the production of a minimum amount of fixed gases.

What I clain is: r

1. A process which comprises subjecting hea-Vy hydrocarbon oil to cracking conditions of temperature and pressure, commingling a cooling oil with the thus cracked oil to prevent excessive decomposition thereof, separating the commingled oils into vapors and unvaporized oil, reacting the unvaporized oil with hydrogen under temperature and pressure conditions adequate to convert a substantial portion thereof into hydrogenated lighter hydrocarbons, removing vapors from the thus treated unvaporized oil and dephlegmating the same to separate heavier from lighter fractions thereof and to form a gasolinecontaining reux condensate, and introducing such gasoline-containing reflux condensate to said cracked oil as said cooling oil.

2. A process which' comprises subjecting heavy hydrocarbon oil to cracking conditions of temperature and pressure, commingling a cooling oil gasoline boiling point range.

with the thus cracked oil to prevent excessive decomposition thereof,` separating the commingled oils into vapors and unvaporized oil, reacting the unvaporized oil with hydrogen under temperature and pressure conditions adequate to convert a substantial portion thereof into hydrogenated lighter hydrocarbons, removing vapors from the thus treated unvaporized oil and condensing the same to form a gasoline-containing condensate, and utilizing a portion of said gasoline-containing condensate as said cooling oil.

3. A. process which comprises subjecting heavy hydrocarbon oil tocracking conditions of temperature and pressure, commingling a cooling oil with the thus cracked oil to prevent excessive decomposition thereof, separating the commingled oils into vapors and unvaporized oil, reacting the unvaporized oil with hydrogen under temperature and pressure conditions adequate to convert a substantial portion thereof into hydro# genated gasoline hydrocarbons, and introducing a portion of the gasoline products of the hydrogenation into said cracked oil to constitute said cooling oil.

4. A process which comprises heating hydrocarbon oil to cracking temperature under pressure while flowing in a restricted stream through a heating zone and sumequently discharging such heated oil into an enlarged zone, cracking the oil by heat and pressure during such treatment,

separating the cracked products into vapors and residue, reacting the residue withv hydrogen under temperature and pressurel conditions adequate to convert a substantial portion thereof into hydrogenated lighter hydrocarbons, fractionating the resultant vapors to condense heaviery fractions thereof, commingling resultant reflux condensate with the heated oil discharging from the heating zone into the enlarged zone, fractionating the vapors evolved in.the enlarged zone independently of the first-named vapors thereby forming additional reflux condensate, supplying such additional reflux fractionated vapors.

5. A conversion process which comprises crack- .ing hydrocarbon oil by heat and pressure while flowing in a restricted stream through a heating zone, separating the cracked oil into vaporous and liquid conversion products in an enlarged zone, removing liquid products from the enlarged zone and supplying the same to a hydrogenating zone, reacting the liquid products in the hydrogenating zone with hydrogen under temperature and pressure conditions adequate to convert a substantial portion thereof into lighter hydrogenated hydrocarbons, separating the resultant hydrogenated products into vapors and unvaporized oil'and fractionating the former` to condense heavier fractions thereof, commingling resultant reflux condensate and at least a portion of said separated unvaporized oil with the hot cracked oil discharged from the heating zone, and finally condensing the fractionated vapors.

6. A conversion process which comp-rises cracking hydrocarbon oil by heat and pressure while flowing in a restricted stream through a heating zone, commingling with the hot cracked oil a hydrogenation residue formed as hereinafter set forth, separating the resultant mixture into vazone, removing liquid products from the enlarged condensate to said heating zone, and finally condensing the.

zone and supplying the same to a hydrogenating oil discharged from the heating zone to constizone, reacting the liquid products in the hydrotute said hydrogenation residue, fractionating genating zone with hydrogen under temperature said vapors independently o! the vaporous prodand pressure conditions adequate to converta ucts from the enlarged zone and combining resubstantial 'portion thereof into lighter hydro* flux condensate formed by this fractionation with 5 genated hydrocarbons, separating the resultant the unyaporized oil to be commingled with said hydrogenated products into vapors and unvahot cracked oil, and finally condensing the trac-v porized oil, commingling at least a portion oi' the tionated vapors.

separated unvaporized oil with the hot cracked JEAN DELA'I'IRE-SEGUY.

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