US1779465A - Hydrocarbon-oil conversion - Google Patents

Description

Oct. 28, 1930. c. P. DUBBS 1,779,465

HYDROCARBON OIL CONVERS ION Filed July 30, 1927 Patented Oct. 28, 1930 UNITED srA'Tas PAT NT oFFIcE cannon almanac!- wnun'rmnnmors, assrenon ".ro uiiivnnsu. on. rno'nucrs comm, or cnrcaoo, ILLINOIS, a'conrona'rron or 80mm naxora mnocanBoN-o Y Applicatiohflted July 80,

The present invention relates to hydrocar-- bon oil conversion, and refers, more particu larly to subjecting hydrocarbon oils to atmospheri'c or substantially atmosphericcracking conditions under cracking or conversion temperature to produce therefrom high yields of usefullow boiling point range hydroca'r bons suitable for motor fuel and the like. It is one of the main objects of the present invention'to produce a product which possesses high anti-knock properties.

It is another object to produce a distillate which 'meetsthe commercial requirements for motor fuel as'to initial and end boiling point range, gravity, et cetera, as a direct product of the process, thus eliminating subsequent expensive distillation and refining steps.-

longed fractionation is permitted, thus con- It is another object of the invention to carry out an operation wherein hydrocarbon oil is subjected to a conversion temperature while being maintained under substantially atmos-v pheric pressure conditions thereby materially decreasing the cost of 'a paratus in which the process may be carrie out.

' 'A still further object of the invention is to provide a process iii-which the, oil to be treat-' ed is adapted to be passed successively throughzones wherein it is brought into physical relationship with vapors progressing in an opposite direction whereby eflicient scrubbin and fractionation ofvthe vapors and 'va-' porization of the low boiling point fractions of the charging stock takes place, that is, vapors evolved in a preceding zone are caused to pass through pools of liquid of progressively'cooler temperature'on their way to the condenser and receiver, whereby repeated and pro.-

densing substantially all of the undesirable heavy fractions and permitting the production of a final distillate which conforms to all of the commercial requirements for .motor fuel.

The unvaporized portions of'the charging stock together with the condensed portions of the vapors are passed successively from zone to zone in a direction counter-current to the flow of the vapors, the temperature of which zones progressively increases. The unvaporized hydrocarbons in the lastzone are reelevationa m wh ch the invention may be carried out.

11. co'nvnnsron 1927. semi no. 209,629.

moved and subjected to the action of heat in a furnace whereby they are raised to a desired cracking. temperature;

In the preferred embodiment of the invention, the zones through which the chargingstock progressively passes to the heating zone,

are preferably externally unheated, that is,

' these zones are not subjected to such heating conditions as would raise the oil passing therethrough to a conversion temperature.

, While it may be desirable tosubject any of said zones'to such heating as would'maintain the temperature to which the oil was raised in the next preceding zone it is'not contemplated that while the oil is passing through these zones it should be raised to such a tem-- perature as would cause conversion.

The utility of the invention, as well as other ob ects and advantages will be hereinafter more particularly apparent.

. The sin le fi gure in the drawing is'a side diagrammatic view of apparatus Referring more in detail to the drawing, 1- designatesa charging stock inlet line in which is interposed a valve (not shown) adapted to be fed by means of pump 2, which draws charging stock from any desired source of'supply, such as storage. Y stock is introduced into one of a series of serially connected chambers 3 wherein the charging stock is brought into physical contact with vapors released from a preceding 0 amber 4, as will be hereinafter described. he chamber 3 is similar to chambers 4, 5 and 6. Each of the chambers 3, 4, 5 and 6 comprisesa metal shell which may be provided with insulation to prevent loss. of heat by radiation. The unvaporized portion of the mediate the height of the chamber 4, pref- The charging ber 3, and is removed through line 7', in which may be interposed a pump 8', and introduced into the chamber 5. A by-pass 9 controlled by valve 10' may be provlded whereby the pump 8' may be by-passed, if so desired in which event the valves 11' are closed. The

oil introduced into the chamber 5 will be sub jected to similar ph sical contact with vapors formed in a prece ing zone, and the unvaporized portions of the oil from chamber 5 ma be withdrawn through the line 7", in which may be interposed a pump 8". A bigpass 9", controlled by valve 10", ma e provided to by-pass the pump 8", in w ich event the valves 11" are closed.

The oil discharges from line 7" into the chamber 6. The chamber 6 is the last of the three chamber 4, 5 and 6 through which the chargingl stock passes. It is understood, of course, t at there may be any number of these chambers, from one to ten, more or less, and that the four chambers shown in the drawings are purely illustrative. In addition, any of these chambers 3, 4, 5 and 6 may be by-passed by manipulation of valves and suitable connecting lines (not shown) but obvious to those skilled in this art.

The unvaporized oil from the chamber 6 may be withdrawn through either or both of the draw-ofi' lines 12, in which may be interposed a valve 13, which line 12 merges with main line 14, in which may be interposed a pump 15, line 14 communicating with aheating tube 16 which may comprise connected lengths of tubing formed into a coil. A by-pass 17 controlled by valve 18 may be connected into the line 14 whereb the pump 15 may be by-passed, if desire in which event the valves 19 are closed.

The heating coil 16 may be mounted in any conventional type furnace or heatin zone 20, which may be heated by means of urner 21. While passing through the heating coil 16 the oil may be raised to the temperature which it has been decided is the desired temperature for most eflicient conversion, which temperature will, of course, depend to a great extent upon the character of charging stock being treated and the types of products desired, all of which is within the skill and knowledge of those versed in the art.

The oil after being heated while passing through the coil 16 is transferred through transfer line 22, in which may be interposed a valve 23, discharging into a suitable soaking instrumentality 24, which may comprise a passageway of any form. While I have illustrated in the drawings the element 24 as com rising a chamber, yet it must be understoo of course, that this element may comprise a coil of any other'suitable instrumentality wherein the tem erature of the oil is maintained at substantiall the temperature to which it was heated whi e passin through coil 16 whereby a prolongatlon o the temperature during which the oil is subjected to the desired conversion temperature is effected. It is obvious, of course, that the ele- 24 with chamber 6. When the soaking element 24 takes the form of a coil this line 27 may be dispensed with. Or it may be desirable to discharge all products of conversion from the element 24 through line 25 as shown, connected to the bottom of said e ement 24. It may also be desirable to separate in element 24 the lighter products of conversion in the form of vapors from heavy portions in the form of liquid, semi-solid or solid form.

If separation is desired in element 24 this element may be provided with a bottom drawofi, as shown at 25' and controlled by valve 26', to permit clean circulation to the balance of this system, while the vaporous products of conversion may be passed from the upper portion of element 24 into chamber 6 through side line 25" controlled by valve 26".

The products of conversion discharged from the soaking element 24 through lines 25 or 25" are passed into the lower portion of the chamber 6 where they come in contact with the oil charged into this chamber 6 through line 7 as heretofore described. This physical contact of this oil with the products of conversion causes preheating of the former and condensation or fractionation of the heavier portions of said products'of conversion. These condensed portions are withdrawn through either or both lines 12 and directed to the cracking coil 16, as heretofore described.

The vapors remaining uncondensed in chamber 6 are withdrawn from the top thereof through line 29, on which may be interposed vapor pump or blower 30, controlled by valves 31. A by-pass 32 controlled by valve 33 may be provided around vapor pump 30. The vapors from the top of chamber 6 are thus passed b means of blower or pump 30 or through y-pass 32 into the lower portion of chamber 5. In chamber 5 the vapors come in contact with the oil charged thereto through line 7 causing a reaction in chamber 5, as heretofore described for chamber 6. The valighter fractions of the chargin Vapors remaining uncondensed, may e Wltllpors uncondensed pass out through vapor line 29', in which may be interposeda pump 30',

controlled by valves 31', which pump maybe bypassed by means of theby-pass 32' con controlled by valve 33. Vapors from line 29' discharge into the lower portion of chamber 4 where they coine into physical contact with the charging stock introduced through the line 7. i The same reaction takes place in the chamber 4 as heretofore described for the chambers 5 and 6, the vapors being removed through vapor outlet line 29", in Wl'llCh may be interposed a pump or blower 30", controlled by valves 31, which pump may be by-passed by means of the by-pass line 3%" controlled by valve 33". The va or s discharging through the line 29" may e introduced to the chamber 3 into which the raw charging stock is introduced. Physical comingling takes place in the chamber 3 between the vapors and charging stock, causing condensation of insufficiently converted or heavy fractions of said vapors and heating and perhaps vaporization of some of the stock.

drawn from the chamber 3 through the vapor outlet line 34, in which may be interposed a valve 35, being condensed in the condenser coil 36 and collected as liquid distillate 1n the receiver 37, which may be provided with the liquid draw-ofi line 38 controlled by valve 39 and with the gas relief pipe 40 controlled by valve 41.

It is to be understood, of course, that any suitable finishing liquid may be introduced to the chamber 3 for the purpose of producing a more stable end point product.- For instance, controlled quantities of the distillate collected in the receiver 37 may be returned to the upper part of the chamber 3,-or a dephlegmator or other suitable lnstrumentality may be connected into the line 34 between the chamber 3 and condenser 36 for this purpose, in which event the reflux may be returned to any of the chambers 3, 4, 5 and 6 or' to the charging line 14.

The operation of the apparatus described in the foregoing description should be ap- Erent to those skilled in this art. The unvaporized portion of the charging stock 1s progressively passed through zones of 1ncreasing temperature wherein vapors from preceding zones which are passing in a coun-' tercurrent direction to the flow of charging stock are brought into physical contact therewith, thus creating to some extent an equilibrium between vapors and liquid whereby the again passing through the eventually removed through the vapor line 34.

-As a feature of the invention, the entire apparatus is adapted to be maintained at atmospheric pressure, that is the pressure imposed by the pumps is only sufiicien't to overcome fractional resistance and is not intended in any .way to impose a superatmospheric pressure on the oil and vapors for the purpose of subjecting same to a cracking temperature under superatmospheric pressure.

The vapor pumps 30, 30' and 30" and only used where it is necessary to impose enoug pressure on the vapors to cause them to pass into the succeeding chamber. In addition, the use of the vapor pumps30, 30' and 30 assist in removing vapors from the preceding chamber through the vapor lines'29, 29 and 29", and in addition may accelerate the flow of liquid through the'coil 16, pipe 22, element- 24, and transfer line 25. a

As a feature of the present invention, in order to permit operating under the principle of what is termed clean circulation, the heavy residuemay be withdrawn through the line 25 controlled by 26, and revented from eating coil or any of the chambers 3, 4, 5 and 6.

Each of the chambers 3, 4, 5 and 6 may be provided with liquid draw-01f lines 42 con-' withdrawn. This residue may be cooled and collected separately or may be combined and used for fuel.

ing to limit the process in any way the following temperature conditions maybe maintained. The oil passing through the heatin coil 16 may be raised to a temperature 0 7 accurately controlled to comply with end boiling point commercial specifications by introducing any of the usual cooling-mediums, such, for instance, as distillate returned from the receiver 37.

From the foregoing it will be apparent that the vapors are caused to pass through zones of successively decreasing temperature while the unvaporized liquid is caused to pass through zones of progressively increasing temperatures, while at the same time causing said vapors to be brought into physical contact with the charging stock, preferably by causing the vapors to percolate through bodies of unvaporized charging stock.

In some instances itmay be desirable to me As an example merely,-and without intendmaintain relatively mild conditions of temperature and pressure on the oil passing throu h the coil 16, which oil would thus be heated to such temperature as would effect conversion of the hydrocarbons without the formation of substantial amounts of solid or semi-solid residue. The conversion effected in this instance, of course, would be limited. In this same operation it may be desirable to limit the soaking time to arrest conversion before substantial amounts of semi-solid or solid residue are formed. Thus, the object of such an operation is to vaporize the oil and effect a partial cracking thereof to separate therefrom, in elements 24, 6, 5, 4 and 3,.the heavier fractions which tend to form substantial coke deposits when subjected to additional cracking. Thereby only the lighter partially converted fractions are subjected to additional cracking, which could be done in a superheater.

This superheater may be connected by the lines 44 controlled by valves 45 communicating respectively with the vapor lines 29, 29' and 29" on one end and on the other with the header 46. The latter communicates with a superheating coil 47 mounted in a furnace illustrated diagrammatically at 48 heated by means of burner. 49. The vapors withdrawn from any of the vapor lines 29, 29 or 29" by obvious. manipulation of the valves 45 pass into the header 46 and through the heating coil 47 where said vapors are subjected to conditions of temperature such that substantial conversion into light lproducts possessing anti-knock properties w en used as motor fuel will be obtained. The vapors may be raised, for instance, to a tem erature o 950 to 1200 F., more or less, an after passing through the superheater they exit through the line 50 with which return branches 51 controlled by valves 52 communicate for returning the heated vapors to a desired vapor line 29, 29 or 29".

In this manner the formation of heavier residue and solid coke is materially decreased below that which would be the result of cracking effected in a single operation, which would produce an equivalent conversion into light products.

On account of the relatively high tempera ture of the vapors being introduced to the chambers 5, 4 and 3 some portions of the charging stock may vaporize particularly in chambers 5 and 4. This vaporized portion will'be subjected to some cracking in the superheater with the vapors resulting from the primary cracking in coil 16. The superheater is preferably interposed between chambers 6 and 5, although means are provided for superheating the vapors passing between chambers 5 and 4 and 4 and 3 if found desirable. Where the vapors are superheated while passing between chambers 5 and 4 or 4 and 3, it might be well to provide additional chambers between chamber 3 and condenser 1 contact with said cracked vapors to a mild cracking temperature in a heating zone, delivering the oil following subjection to said mild cracking temperature to a vaporizing zone, removing from said vaporizin zone vapors and liquid oil before the cracking reaction has proceeded to the extent of forming coke, subjecting the vapors following their removal from said vaporizing zone to a cracking temperature while in the vapor phase to supply the cracked oil vapors for contact with the incoming untreated oil.

2. In the art of converting high boiling point hydrocarbons to low boiling point ydrocarbons, the process which comprises contacting untreated oil with cracked oil vapors just following the subjection of such vapors to a cracking temperature in the vapor base, subjecting the untreated oil followmg contact with said cracked'vapors to a mild cracking temperature in a heating zone, delivering the oil following subjection to said mild cracking temperature to a vaporizing zone, removing from said vaporizing zone vapors and liquid oil before the cracking reaction has proceeded to the extent of forming coke, subjecting the vapors following their removal from said vaporizing zone to a cracking temperature while in the vapor phase to supply the cracked oil vapors for contact with the incoming untreated oil, and effecting the operation of the process under substantially atmospheric pressure.

3. In the art of converting high boiling point hydrocarbons to low boiling point hydrocarbons, the process which comprises contacting untreated oil with cracked oil vapors just following the subjection of such vapors to a cracking temperature in the vapor phase, subjecting the untreated oil following contact with said cracked vapors to a mild cracking temperature in a heating zone, delivering the oil following subjection to said mild cracking temperature to a vaporizing zone, removing from said vaporizing zone vapors and liquid oil before the cracking reaction has proceeded to the extent of forming coke, subjecting the vapors removed from said vaporizing zone to partial fractionation, in then subjecting the partially fractionated vapors to a cracking temperature while in the vapor phase to supply the cracked oil vapors for contact with the untreated oil.

4. In the art of converting high boiling point hydrocarbons to low boiling point hydrocarbons, the process which comprises contacting untreated oil with cracked oil vapors just following the subjection of such vapors to a cracking temperature in the vapor phase, subjecting the untreated oil following contact with said cracked vapors to a-mild cracking temperature in a heating zone, delivering the oil following subjection to said mild cracking temperature to a vaporizing zone, removing from said vaporizing zone vapors and liquid oil before the cracking reaction has proceeded to the extent of forming coke, subjecting the vapors removed from said vaporizing zone to partial fractionation,

chamber to physically contact with liquid oil therein, removing vapors from said last chamber and passing the same through the remaining chambers of the series in a direction opposite to the flow of charging oil through the series of chambers, subjecting vapors from one of said chambers to vapor phase cracking during its flow to the next preceding chamber in the series, and removing introducing vapors evolved by the heating to said last vapors evolved by the heating to said last chamber to physlcally contact with liquid oil therein, removing vapors from said last chamber and subjectmg the same to cracking in the vapor phase, passing the cracked vapors resulting from the vapor phase cracking through preceding chambers in the series in a direction opposite to the flow of charging oil therethrough, and removing and condensingvapors from the first chamber of the series as a final product of the process.

In testimony whereof I aifix my signature.

CARBON P. DUBBS.

and condensing vapors from the first chamber of the series.

6. An oil cracking process which comprises passing chargin oil for the process through a series of cham ers maintained at progressively increasing temperatures from first to,

last, removin unvaporized charging oil from the last cham er of the series and passing the same through a heating zone, introducing vapors evolved by the heatin to said last chamber to physically contact with liquid oil therein, removing vapors from said last chamber the last chamber of the series an and passing the same through the remaining chambers of the series in a direction opposite to the flow of charging oil through theseries of chambers, subjecting vapors from each of said chambers but the first to vapor phase cracking during its flow to the next preceding chamber, and removing and com densing va ors from the first chamber of the series as a al product of the process.

' 7. An oil cracking process which comprises passing charging oil for the process through a series of chambers maintained at progressively increasing temperatures from first to last, removing unvaporized chargin oil from passing the same through a heating zone, introducing

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