US2108649A - Treatment of hydrocarbon oils - Google Patents

Description

Feb. 1 5, 1938. v

AIR

CHAMBER i A. HQCALDERWOOD TREATMENT OF HYDROGARBON OILS Filed June 17, 1955 QUENCHING CONDENSER .COKING INVENTOR ALLAN H. CALDERWOOD TTORNEY Patented Feb; 15, 1935 UNITED 'STATES PATENT OFFICE 2,108,649 TREATMENT OF nYnaooAanoN ons Allan H. Oalderwood, Martinez, CaliL, assignor to Universal Oil Products Company, Chicago, 11]., a corporation of Delaware Application'June 17, 1935, Serial No. 26,919

2 Claims. (01. 196- 49) a water while in the form of-a spray, whereby it is broken up into relatively small particles of a semi-solid asphaltic nature, followed by reduction of said semi-solid particles to substantially dry coke.

-While the present invention is directed to the treatment of cracked residual oils obtainedin heated state from a cracking system, it is not limited to the use of any 'particulartype of cracking system for the production of said residual liquid, and the latter may be obtained from either a relatively high pressure cracking zone or may be the,result of further vaporization, at substantially reduced pressure, of residual liquids, produced at relatively high superatmospheric pressure.

The inventionalso contemplates, when desired,

' controlled partial o'xidation of the cracked residue prior to quenching the same. This method of treatment has been found in some cases to assist the production of semi-solid asphaltic particles from the cracked residual liquid upon quenching, which state is highly desirable in order to facilitate handling of the residual material prior to the coking step.

Any desired method of coking thesemiesolid asphaltic particles resulting from the treatment of the cracked residue in the manner provided by the present invention may be employed within the scope of the invention and, since it is possible to store the semi-solid asphaltic particles for a considerable length of time'without their coalescing, it is not essential that the coking step be accomplished simultaneously with the other stages of the process. Preferably, however, the coking operation is simultaneous with the cracking, oxidation and quenching stages of the process in order to eliminate the necessity of providing storage facilities and in order that the vaporous hydrocarbons recovered from thecoking stage may be returned for further treatment to the cracking stageof the system.

The accompanying diagrammatic drawing illustrates one specific form of apparatus in which the process. of the invention may be accomplished.

Referring to the I drawing, hydrocarbon oil charging stock forthe cracking operationgwhich may comprise any desired type of hydrocarbon oil, is supplied through line I and valve 2 to a pump 3, byflmeans of which it is fed through line 4 and may be directed, all or in part, through line 5 and valve G'to fractionator I, or it may be supplied, all or in part, through line 8 and valve 9 direct to cracking coil Ill. Any charging stock supplied to the fractionator, as described, may commingle therein with the hot conversion products undergoing fractionation, serving to assist their fractionation and being thereby preheated and subjected to vaporization. The components of the charging stock supplied to the fractionator boiling above the range of the desired final light distillate product of the process collect, together with the reflux condensate formed in this zone by condensation of the insuificiently converted com.- ponents of the vaporous conversion products supplied thereto, and the commingled materials are withdrawn fromthe lower portion of the fractionator through line H and valve I 2 to pump H, by means of which they are fed through line H, valve .l 5 and line 8 to conversion in heating coil l 0. A furnace l6 of any suitable form supplies the required heat to the oil passing through heating coil ID to subject the same to the desired conversion temperature, preferably at a substantial superatmospheric pressure, and the heated products are discharged from the heating coil through line l1 and valve I8 into reaction chamber I9.

Chamber I9 is also preferably maintained at asubstantial superatmospheric pressure, which may be substantially the same or somewhat lower than the'pressure employed at the outlet from the heating coil. Although not indicated in the drawing, chamber I9 is preferably insulated in order to preveutthe excessive loss of heat therefrom by radiation-so that conversion of the heated products supplied to this zone, and particularly their vaporous components, may continue therein. Both vaporous and liquid conversion products may be withdrawn in commingled state from the lower portion of chamber l9 through line 20 and may be directed through valve 2| into vaporizing chamber 22, wherein the liquid conversion products are subjected to appreciable further vaporization by a substantial reduction in the pressure imposed thereon. It is, however, entirely within the scope of the invention to withdraw substantially only liquid conversion products, or liquid conversion products and a reguiated quantity of the vapors, from the lower portion of the reaction chamber, in the manner illustrated, and to separately remove substantially all of the remaining vaporous products from any desired point .or plurality of points in the reaction chamber above the point of removal of the liquids. In the case herein illustrated provision is made for separately removing vapors from chamber ll through line 22, and directing the 1 tion is accomplished in this zone.

ber 22 in the manner previously described, further vaporization of the liquids and final separa- The vapors evolved in chamber 22, as well as any vaporous products supplied thereto from chamber l9, are

densate and arereturned, in the manner previously described, to further conversion in heating coil Ill. Fractionated vapors of the desired end boiling point are withdrawn, together with uncondensable gas produced by the process, from the upper portion of fractionator 1, through line 21 and valve 28, and are subjected to condense tion and cooling in condenser 29. The resulting distillate and gas pass through line and valve 3| to collection and separation in receiver 32. Uncondensable gas may be released from the receiver through line 23 and valve 34. Distillate may be withdrawn from receiver 52 through line and valve 36, to storage or to any desired further treatment. When desired, a regulated portion of the distillate collected in receiver 32 may be recirculated, by well known means not illustrated in the drawing, to the upper portion of fractionator l to serve as a cooling and refluxing medium for assisting fractionation of the vapors and to maintain the desired vapor outlet temperature from the fractionator.

Residual liquid remaining unvaporized in chamber 22 is withdrawn from the lower portion of this zone through-line 31 and may be directed, all or in part, through valve 38 to pump 29,'by means of which it is fed through line 40 and valve 4| into quenching chamber 42. Provision is also made in the case here illustrated for directing residual liquid withdrawn from chamber is from line 20 through line 43 and valve 44 into line 4|, and thence to quenching chamber 42. Provision is also made for withdrawing a regulated portion or all of the flash distilled residual liquid from chamber 22 to cooling and storage,

, or elsewhere as desired, by means of line 45 and suitable spray nozzle such as indicated, for example, at 41, and the sprayof liquid residue is caused to intimately commingle in this zone with a spray of cold water which is supplied to chama,1os,e4a i Other air inlet lines not illustrated may be providedat suitable intervals along line 44in order that the amount of oxidation produced in the cracked residue may be controlled not only by the temperature of the residue; and the amount a of air commingled therewithibut also varying by the point of introduction of the air and the consequent time of contact between the two prior to quenching.

The product of the treatment of the cracked residue in the manner above described is a mass of individual particles of semi-solid material of more or less asphaltic nature,.ranging for example from one-eighth to three-eighths of an inch or thereabouts in diameter. These individual particles'have a relatively hard outer crust and do not readily coalesce even when allowed to stand under ordinary-atmospheric conditions for a period of several months. I am thereby enabled to produce by this method of treatment a;

cracked residual oil in semi-solid state and in relatively finely divided form which may be readily handled by ordinary methods without the danger of coking so often encountered when it is attempted to convey ,heavy cracked residues in I heated fluid state. The present method of treatment also, eliminates leakage and the usual mess attendant with the handling of heavy. residual oils in ordinary conveying equipment. It is therefore possible, in conjunction with the other features of the present invention, to employ practically any of the various satisfactory methods of coking for the semi-solid residual particles.

In the case here illustrated residual material may be allowed to accumulate in the lower portion of chamber 42, together with the water supplied to this zone, from which the water and residual particles are conveyed through a suitable helical conveyor, orthe'like, indicated at 53, the residual particles passing onto a suitable belt type conveyor 54, while the water, which collects within pit 55, may be withdrawn therefrom through line 56. The residual particles are dis charged from the upper end of conveyor 54 into hopper 51 of coking oven 58.

The coking oven in the particular case here illustrated comprises suitable refractory walls 59 housing a continuous conveyor 60, preferably constructed of suitable metallic alloys capable of withstanding high temperatures. The particles of semi-solid residual material pass from hopper 51 onto one end of the upper surface of conveyor 60, moving thereon through the coking oven to the opposite end of the conveyor and being reduced to relatively dry coke during their travel through the oven. Jets of water may be directed by suitable means, indicated for example by line SI and valve 62, against the surface of the coke at the discharge end of the conveyor in order to crack and loosen the same from the surface of theconveyor belt, or it may be otherwise removed in any suitable well known manner, such as for example by means of a scraper, not illustrated, and is discharged from the coking oven through a suitable discharge device 83 to storage or elsewhere, as desired. Suitable burner ports, such as indicated for example at 64, are provided in the side walls of furnace 59, and burners, the tips of which are indicated at 65, preferably direct a combustible fuel and air mixture upward at an angle against the roof of the coking oven so that a majorportion at least of the heat required for coking of the semi-solid residual particles is supplied thereto by radiation from the roof of the coking oven and, in order to minimize mixing of the combustion gases and the hydrocarbon vapors evolved from the material underv going coking, a combustion gas outlet is preferably provided near the roof of the iurnace, for example, flue 66 controlled by damper 61, while a hydrocarbon vapor outlet is provided at a relatively remote point or plurality of pointsin the oven. In the case here illustrated a vapor collecting header 68 is provided beneath the upper surface of conveyor 60. The hydrocarbon vapors evolved during the coking operation are withdrawn from the coking oven through line 69 and may be directedtherefrom through line ill and valve ii to condensation and collection by wellv known means notv illustrated, or they maybe directed through line 12 and valve 13 to pumpor compressor It and thence through line, and

. eration are returned as described to chamber 22,

any entrained heavy liquid particles or high boiling components of the vapors unsuitable for conversion in the heating coil may be collected with the residual liquid conversion'products in chamber 22 for further treatment therewith in the manner described, while the remaining lower boiling components of the vapors are directed to fractionation in fractionator 1, whereby any components thereof boiling within the range of the desired final light distillate product of the process are collected as such, while their higher boiling components are condensed as reflux condensate and returned to heating coil III for further conversion. 1

As a specific example of the operation of the process of the invention, the charging stock supplied to the cracking system comprises a California gas oilof about 32 A. P. I. gravity which is subjected, together with the reflux condensate recovered from within the system, to a conversion temperature, measured at the outlet from the heating coil, of approximately-960 F. at a super atmospheric pressure of about 350 pounds per square inch. This pressure is substantially equalized in the reaction chamber and is reduced in the vaporizing chamber to a pressure of approximately 50 pounds per square inch, the succeeding fractionating, condensing and collecting equipment being operated at substantially the same pressure. Non-vaporous residual liquid of about 3 A. P; I. gravity is withdrawn iromthe vaporizing chamber of the cracking system at a temperature of approximately 160 1". and the heated oil is introduced through atomizing nozzles into a chamber wherein it is contacted with a cold water spray.

residual oil shortly before the'oil is quenched by contact with the water. The resulting product is a mass of relatively small particles or semi-solid material having a specific gravity 0! apprbximately 1.1399, a melting point of approximately 307 F., which contains approximately 86.81% by weight of volatile matter, approximately 32.81% fixed carbon and about 0.88% ash and-has A relatively small amount .01 air is commingled with the stream othot a solubility oi petroleumether of approximately 20.4% by weight. This material is of a relatively hard nature showing no penetration at 77 F. and is passed by means 'of conveyors from the lower portion of the quenching zone to a coking oven wherein it is reduced to low volatile coke at a temperature of approximately 1200 F. Vaporous products from the coking oven are returned to the vaporizing chamber of the cracking system. This operation will yield, per barrel of charging stock, approximately 65 per cent of motor fuel of good antiknock value and approxivmately '70 pounds of low volatile good quality coke, the remainder being chargeable, principally, to uncondensable gas.

' I claim as my invention.

1. A process for the treatment of residual liq uid resulting from the pyrolytic conversion of hydrocarbon oils which comprises withdrawing said residual liquid in heated state from the conversion process wherein it is produced, admixe ing an oxidizing gas with the residual liquid while the latter is at a suficient temperature to be partially oxidized and passing the"heatedoil through a spray nozzle into a quenching drum, contacting the oil spray in the drum with relatively cold water, whereby to quench the oil and cause the formation of relatively small particles of semisolid residual material which do not readily coalesce, passing said semi-solid residual particles fromthe quenching zone to a coking zone, reducing same therein to substantially dry coke, and returning hydrocarbons evolved during the coking operation to the conversion process for further treatment.

2. In a process for the treatment of hydrocarsion conditions of cracking temperature and super-atmospheric pressure in a heating coil and communicating reaction chamber, the resulting vaporous and liquid conversion products separated, the latter subjected to further vaporization in -bon oils wherein the oil is subjected to convera zone of substantially reduced pressure relative.

to that employed in the reaction chamber, the vaporous conversion products, including those evolved by said further vaporization of the liquids, subjected to fractionation resulting in the formation of refiuxcondensate, the reflux condensate returned to the heating coil for further conversion, fractionated vapors of the desired end-boiling point subjected to condensation and the resulting distillate recovered. the improvement which'comprises withdrawing non-vaporous residual liquid in heated state from said zone of reduced pressure vaporization, passing the same in the form of a relatively tlnespray intoa quenching chamber, commingling oxidizing gas in relatively small regulated quantities with-the stream of hot'residual liquid passing from said reduced pressure zone to the quenching chamber,

. contacting said spray with a spray of relatively

Images