Патент USA US2406313код для вставки
Aug. 27,1946. J. M. ‘BAR-RON CRACKING AND CCKING HYDRQCARBON OIL‘S ‘Filed Nov. 28, 1942 2,406,313 an 3,. r23.1; 02:58\. _ ro 40 OT '. ozF1‘:u0 ‘ | .n'lmm l . ' nmumm h IIIIIIIIIIMIIIIII ‘ _ wvvvlvllv mmlm ~11 - Jossér-i Mascu Bunch INVENTOR ~ “is? HIS Patented Aug. 27, 1946 2,406,313 UNITED STATES PATENT or 2,406,313 CRACKING'AND COKING HYDROCARBON . ‘ OILS Joseph 'Mason Barron, Port Arthur, Tex.,.assig11or' ‘ to The Texas Company, proration of Delaware New York, N. Y., ‘a cor 'Application'November 28, 1942, Serial No. 467,177 ‘:2 ‘Claims. 7 (0]. 196-49) 1 2 This invention relates to certain "improvements in the cracking and coking of hydrocarbon oils. The invention is concerned with the coking of coking chamber ‘is greatly reduced Witha con sequent material diminution in priming tend encies. residual constituents from a pressure cracking operation and contemplates a combination cracking and coking process in which a conden The practice of the invention thus makes possible the maintenance of high charg ing rates to the coking drum and high levels therein While avoiding priming, with the result sate stock is subjected to acracking temperature in a heating zone and the heated e?luent there that a maximum amount of coke is produced per coke drum cycle. 7 from subjected to ‘countercurrent contact with a Additional advantages of the high ‘temperature heavy or residual stock "in a reaction chamber 10 wherein separation of vapors from liquid residue in the reaction chamber made possible by the countercurrent operation therein are ‘the result occurs and in which'theresidue is ?ashed to coke bymeans of its contained heat. v ant ‘higher‘conversion per pass on the material The invention is based ‘upon ‘the discovery that delivered to the reaction’chamber and the im~ by having the heated condensate stock and the 15 provement in the e?iciency of the operation by reason of the fact that the reaction chamber va pors pass directly to the dephlegmating or frac tiona'ting portion of the system at maximum ‘tem peratures. ‘In accordance with the invention a condensate stock is passed through a heating ‘zone and de~ livered to the lower portion of arreaction cham ber into the upper ‘portion :of'which a, heavy oil or highly aromatic character well adapted for fuel oil ‘blending. This ‘heavy condensate may be residual stock is introduced ‘ ' -- Withdrawn ‘as a fuel oil product of'the process. However, ‘due to the heat ‘made available by the countercurrent contact in the reaction chamber it is advantageous to combine the heavy tarry condensate with the cracked'residue being de livered to the coking drum. The primary de phlegmation of the coke still vapors is carried on at "relatively high temperatures within the crack reaction chamber is'maintained at ajhigh crack ing temperature su?icient that ‘upon ‘the v?ashing of the residue a conversion to coke ‘will occur. ing temperature range‘and coking‘ tendencies'may ‘be reduced to a negligible quantity Withinv the dephlegmator by maintaining therein a constant circulation of the-condensate formed._ This oil‘; sure is lowered and the residue ?ashed to coke. In'the prior art vpractice coking has ‘been ac complished with the aid of considerable quanti cu-lation together with the return of the primary condensate to the coking drum insures that this cipal dif?‘culties encountered vhas _ been that 40 heavy material will tbe looked in the coke drum occasioned ‘by the priming of the coking drum. and not in the dephlegmator, or that the ‘con densate may be withdrawn ‘as a liquid product in cases wherein it is desired ‘to obtain such fuel In this priming, potential coke-forming constit uents ‘are carried with the e?luent vapor-s from product. the coking drum ‘and create coking ‘difficulties in the vapor line and in the dephlegmatin'g or. frac tionatin'g portion of the system. In order vto 445 avoid this dii?culty it has been necessary in the past to Operate with relatively low charging - ' ‘The deph‘legmated coke still vapors from the primary dephlegmating operation are combined with the vapors separately Withdrawn ‘from the reaction chamber and subjected to dephlegma rates to the coking drum and to maintain rela tion with charging stock such as topped or re tivelyv high outage gauges therein, the outage duced crude and the resultant mixture ‘of reflux gauge being the height of the space in the drum "50 condensate and unvaporized ‘charging stock is di In‘accordance with the . rooted to the upper portion of 'the reaction cham present invention, since ‘the material directed to the coking ‘chamber is essentially ‘a liquid, ‘the quantity of vapors and gases evolved from the ‘ further fractionation to separate a higher i-boil above the coke level. ber. The uncondensed vaporsfare subjected to ing re?ux ‘condensate ifrom flower boiling prod !55 vmtsand..this re?ux condensateis cycled through 2,406,313 amount of cooling is supplied to the dephlegmat ing zone 25 so as not to unduly reduce the tem perature and so as to obtain a condensate con a heating coil wherein it is subjected to a crack 7 ing temperature and the heated e?iuent is dis charged into the lower portion of the reaction sisting of extremely high boiling constituents col chamber for countercurrent contact with the heavier stock. For the purpose of more fully explaining the lected as a tarry condensate at the bottom of the dephlegmator. A portion of this heavy con ' densate is continuously withdrawnjthrough a line 28 and directed by a pump 29 through a line now had to the accom 30 to the upperportion of the dephlegmating panying ‘drawing which is a diagrammatic eleva tion of an apparatus adapted for the practice of 10 zone 25. The function of this circulation is not to accomplish any cooling but merely to establish r the invention. ‘ In the apparatus illustrated a heating coil in ,_ is disposed in a furnace ll adapted to heat the, ' ‘and maintain a ?ow of liquid through the de ' phlegmating zone ?uent passes through a transferline l2 to a re action chamber l3 which'is vertically disposed which will prevent coking. . Heavy dephlegmateor condensate is withdrawn oil to a cracking temperature. The heated ef-' the'dephleg'mator 25 through a line 3| and 15"- from system as a fuel oil product discharged from the and heat insulated. As illustrated, the transfer of the ~re- ' line extends within the lower portion an enlarged ‘ action chamber andttermin'ates in :pipe or section l4 through which the heated pump 32 through a line 33 to the coking drum 22 or to the transfer line 20, so as to combine the heavy tarry material with ,or is directed by. a I the mixture of vapors and liquid which is passed are discharged in an upward direction 20 from the reaction chamber 13/00 the coking products against a ba?le l5. In practice with a three- _ The dephlegmated ‘coke still vapors pass up-v ‘ inch transfer line the element In may be com wardly from theprimary dephlegmating zone 25 posed of a six-inch pipe. The products passing from the coil It to the reaction chamber will to the dephlegmating zone 26 wherein‘ they ‘are’ consist largely of vapors and gases and. upon 25 combined with the vapors which are separately withdrawn from the reaction chamber l3 and being discharged through the enlarged. pipe [4 which are introduced through the vapor line [9 against the baf?e IS an e?icient diffusion of i the anda pressure reducing valve 34. In the de vapors and gases is accomplished.’ A black oil phlegmating zone 26 the combined vapors are or residual stock is'introduced to an upper por tion of the reaction chamber l3 through a ‘line 30 dephlegmated with charging stock, such as crude drum l6 which extends within vthe reaction’ chamber 22. ' ' - ‘ » petroleum or topped or reduced crude, introduced by a pump 35 through line 36. The resultant mixture of re?ux condensate and unvaporized l1. The spray I1 is arranged to spray thelliquid charging stock is withdrawn from the tray 21 oil in a downward'direction through the cham 35 through a line 31 and directed by a pump 38 .ber'so as to bring the liquid oil into intimate through the line It“ to the reaction chamber. [3. contact with the rising vapors. It is desirable to from the rdephlegmate Uncondensed vapors-pass ‘ have an unobstructed space between the‘ dis ing zone 26 through a vapor line 39 to a frac tributor l5 and spray nozzle l1, free from ba?les tionating tower 40. This tower is equipped with or any other contact elements, since it is con templated to maintain such elevated tempera 40 bubble trays or othersuitable vapor-liquid con and terminates in a distributor or spray nozzle tures therein that injurious coking would take place if surfaces were presented upon whichcoke deposition could take place- At the top of the chamber a ring spray pipe l8 may be disposed for spraying oil against, the wall of the chamber so as to produce, a down?owing liquid ?lm which ' is conducive to the prevention of coke deposits tact elements and is supplied with conventional cooling or re?uxing means (not shown). The vapors‘ are subjected to fractionation therein to separate a lighter product of desired boiling point from higher boiling re?ux condensate. There-P flux condensate is withdrawn through a’ line 4| : and directed by apump 42 and line '43 to the heating coil Ill. The overhead vapors pass to a residue;‘ takes condenser 44 thence to a distillate receiver or Separation of vapors from liquid The separated 50 gas separator 45 wherein the desired gasoline ' place in the reaction‘chamber l3.upper portion of Q on the wall of the chamber.» I or naphtha distillate is collected. vapors are withdrawn from the 7 , A convenient method of supplying- the limited the chamber through a vapor line l9. Liquid amount of cooling required inv the dephlegmat is prevented from accumulating in the chamber ing zone 25 is to withdraw a smallportionof by the rapid withdrawal "of liquid residue there from. In practicea very slight amount of vapor .55 the re?ux condensate from line 4| through a branch line 46 thence through a cooler 41, and *may be withdrawn with the liquid, an amount sufficient to insure. that no liquid level is direct the cooled condensate by a pump 48 and merely line 49 to the dephlegmating section 25 or con maintained in the reaction chamber. The’ resi ‘ a line 20 and pressure veniently to the line 30. The line 43 may be ' due is withdrawn through 60 reducing valve 2i to a coking drum 22 wherein provided with a branch-line 56 by which a rel—. atively small portion of the hot condensate may it is converted to coke by means of itscontained be directed to the ring spray 18 for supplying heat.~ In practice a plurality of coking drums the down?owing ?lm to the reation chamber are employed so that while one is on stream the iii. If desired, this hot condensate spray may other or others may be down for coke removal be eliminated and ,only- the black oil, conducted and cleaning and‘thus continuity in the com plete process is maintained. The coking drums through line l3,_admitted to the upper portion of the reaction chamber, in which case the black are suitably heat insulated. V t ‘ ' The vapors from the coking drum pass through oil is preferably introduced at the top of- the a primary dephlegmating zone. chamber and sprayed in such a way that a por ' a vapor line 23 to tower 24 is provided having a As illustrated, a lower section 25 and an upper section 26 sep tray 21. The vapor line 23 ' arated by a trapout tion thereof will be directed against’the wall of the chamber to produce a down?owing ?lm; Inpracticing the invention typicalloperating conditions involve temperatures of ,1015°jF.-,-1030.° the vapors from the coking operation are ,sub F..in the outlet of theiheating coil, l9, tempera+ .jected to a separate dephlegmation. 1 A limited 75 communicates with the lower section 25 wherein ‘ v 2,406,313 tures of 920° F.-925° F. in the bottom of the I claim: reaction chamber I 3 under a pressure of 350 6 p. s. i., coke drum temperatures of 850° F.—855° F. under a pressure of 160 pounds, temperatures of 900° F.-910° F. in vapor line H), temperatures of 920° F.-925° F. in the e?iuent passing from the reaction chamber to the transfer line 20, a pres— sure of 150 pounds in ‘the tower 24 with tempera tures of 790° F.-810° F. at the bottom of de phlegmating zone 25 and temperatures of 800° F.-810° F. in the trapout tray 21 and with a pres l0 sure of 135 pounds in the tower 40 with tempera tures of 680° F.—700° F. at the bottom of the tower. It is not necessary to coking drum other than that of the entering oil. 15 the reaction chamber at tempera tures upwards of about 920° F. and delivering it ing streams, maintaining a' temperature approxi ' to the coking chamber autogenous conversion to 20 mating 920-925° produce a marketable coke is readily accom plished. The improved results made vention are shown by a comparison' with the prior practice. ' 25 ing and consequent coking the primary dephleg so' mator. The present invention has made it pos sible to reduce the outage gauge to 20 feet, that 35 as low as 15-17 feet, that is with coke depths of 23-25 feet, with a consequent increase in fresh charge capacity of 30 %-50%. While the practice of the invention does not (0 preclude the passage of the 45 50 upper portion of the reaction chamber. .2. The process according to claim 1 wherein the said heavy tarry condensate is combinedwith liquid residue being delivered to the coking zone for coking. 55 JOSEPH MASON BARRON.