Патент USA US2409387код для вставки
v15, 1941s.v E. B. PECK 2,409,382 AVIATION GASOLINE PRODUCTION Filed larch 11, 1942 v #87. Pnmrrngc ‘ . Con yams: FEED INLET NAPIITIIE'NB Nanvrmsnqs: H84 TING t Ana can; don. ,7 , ‘1:33 é I‘?1 0 O 78 _ . ' Patented Oct. 15, 1946 2,409,382 UNITED" STATES PATENT OFFICE AVIATION GASOLINE PRODUCTION Edward B. Peck, Elizabeth, N.‘ J ., assignor, by mesne assignments, to Standard Catalytic Com pany, a corporation of Delaware Application March 11, 1942, Serial No. 434,206 1 Claim. (01. 196-49) 1 2 The present invention relates to improvements in the manufacture of gasoline and, more partic~ 'ularly, ‘it relates to improvements in the produc tion of aviation gasoline by removing from gas oline or naphthas low octane fractions by frac tional distillation and thereafter subjecting the ed fraction to a two-stage catalytic treatment to produce aromatics. ' A more speci?c object of my present invention is to separate from a gasoline or naphtha of low octane number the lowest octane fraction and to produce from the separated fraction by a combination of dehydrogenation and aromatiza tion, toluene under conditions conducive to max imum yields and minimum coke formation. low octane fractions removed to a two-stage op eration, in the ?rst stage of which naphthenes present in the said low octane fraction are de A still more speci?c object of my invention is hydrogenated to form the-' corresponding aro 10 to segregate at least one of the low octane frac matic derivatives, thence separated ‘from the tions of a naphtha, to thereafter subject the para?ins, and in the second stage of which the fraction to catalytic reforming in the presence of paraf?nic constituents are aromatized catalyt hydrogen to aromatize the naphthenes and re ically. Prior to my invention, it was known that the 15 duce unsaturation by hydrogenating ole?nic hy drocarbons, to thereafter separate the naph octane number of a gasoline could be improved thene conversion products from the unchanged by removing certain fractions by distillation, and para?inic constituents, and then to aromatize the it has been further proposed to hydroform the said para?in constituents. ‘ . low octane number fractions and blend them A still further object of my invention isto 20 back into the gasoline. For example, it has ‘been subject a fraction of the naphtha or gasoline proposed heretofore, in order to improve the‘ oc boiling within the range of from about 180-220° tane rating of the gasoline and particularly the and containing naphthenes and heptane par octane rating as determined by actual road tests, afn‘ns and ole?ns essentially to a two-stage proc to separate the intermediate fractions, say those ess, in the ?rst stage of which the naphthenes boiling within the range of from ZOO-325° F., and are converted to aromatics, while the heptanes to subject these fractions to a catalytic reform‘ are substantially unchanged, and after separa ing operation in the presence of added hydrogen tion of the aromatics from the para?ins to con and thereafter to combine the hydroformed frac ‘ vert the latter to toluene. tion with the other fractions to produce a gaso Other and further“ objects of my invention will line of greatly improved octane rating. appear from the following more detailed descrip The present invention as stated. carries out tion and claim. ‘ the conversion of the low octane fraction of a My invention will be best understood by setting gasoline or naphtha in two steps, with intermedi forth a speci?c example illustrating a preferred ate separation of reaction products in the ?rst modi?cation of my invention and also by refer stage or step. In the ?rst step, the naphthenes ence to the accompanying drawing in which I or hydroaromatics are dehydrogenated to aro have set forth diagrammatically a ?ow plan il matics while ole?n hydrocarbons are hydrogen lustrating, apparatus elements in which my im ated to decrease the unsaturation of the frac proved process may be carried into practical ef tion. In other words, my present invention is fect. , carried out particularly with respect to the ?rst 40 Referring in detail to the drawing, an East step mentioned above under selective hydrogena Texas virgin gasoline boiling within the range tion-dehydrogenation so that aromatics are formed from hydroaromatics, while ole?ns are hydrogenated. This result may be accomplished in the presence of a proper catalyst and under rig." ‘proper operating conditions, and I prefer to use a catalyst composed of a mixed sulphide of nickel and tungsten (2 mols of NiS and 1 mol of W83). After separation of the aromatics and hydro genated ole?ns by distillation and/or solvent ex tractions, the normal paraf?nic residue is aroma tized. The aromatized can be carried out using chromic oxide catalyst supported on activated of from about ‘YO-300° F. and having an octane number as determined by the A. S. T; M. method -' of 60, is charged to the system through line I, thence heated in a furnace 3 to‘vaporization temperatures, thence withdrawn through line 4 and discharged into a fractionating column 6. An overhead fraction and a bottoms fraction are recovered through lines 8 and Hi, respec tively, and these fractions are combined and col lected in a receiving drum l2. This product in the example given will have an octane number of about 70. An intermediate fraction: boiling from alumina or some other suitable catalyst. ISO-220° F. is withdrawn from the fi‘actionator through line M. This fraction withdrawn from the system through line I4 contains ‘naphthenes and. normal heptane, together with some ole?n's, although the amount of the latter is ‘rather lim , The main object of my present invention therefore is to distill a gasoline or naphtha of low octane number to separate out the lowest octane fractions, to leave a residue of greatly ‘im proved octane rating, and to subject the separat 60 ited. ' ~ ' 2,409,382 3 4 This material is discharged into a second fur nace 16 where it is heated to a temperature of lyst, which catalyst is nickel tungsten sul?de. It will be understood that numerous modi?ca tions of my invention may be made by those :skilled in the art without departing ‘from the “spirit thereof. The fra‘cticn separated through line H, for example, from fractionator 6 may In order to saturate any ole?ns present in the have a different boiling range from that herein hydrocarbons charged to reaction vessel 20, hy ibefore set forth, namely, from 180-220° F., that is drogen from some source is also discharged into to say, it may be a hexane or an octane fraction about 800-950" F..and thence discharged through line [8 ‘into a reaction ‘vessel 20 containing cata and, if so, of course the aromatic product pro the reactor 20 through lines'22 vand .18, the amount of hydrogen being such that it exerts a ‘partial '10 duced would be benzene or one of the xylenes. Alsoythe original charging stock may have a dif pressure of 50-80% of the total pressure. The ferent boiling range from that hereinbefore set pressure prevailing within reactor '20 is of the forth, although preferably it is a fraction boiling order of 750-1000 lbs/sq. in., and the feed rate within the gasoline range. Furthermore, also it is of the order of about 0.5 volume of ‘oil per volume of reactor per vhour. Under the condi 15 should be pointed out that the charging oil de livered .to the system through .line I may be a tions stated, the naphthenes are dehydrogenated cracked stock, that-is to say, it may be a gasoline to form toluene, while the ‘para?ins ‘present .in fraction produced by thermally or catalytically the'ly'apors are substantially unchanged. Reac .cracking gas oil and, if so, it may contain con tion ‘products are withdrawn overhead from re =a'ctor"2ll ‘through ‘line 26 and discharged ‘into a 20 .siderable quantitiesoi ole?ns which means that ‘the amount of hydrogen employed in reactor .20 second ‘fractionator ‘28. From fractionator 28, should be sumcient to saturate ‘the ole?ns. If it the ‘toluene formed is Withdrawn through line 30. :is acracked gasoline, particularly if it :is .a cata The overhead product consisting essentially of lytically cracked gasoline, the removal of the heptane is withdrawn‘through line 32, thence dis charged ‘into a third heater 34 where it is heated 125 lowest octane fractions may produce a residual product of very high octane rating, namely, an ‘to a=temperatureoffrom about 900-1050° with ‘a ‘temperature-of about 960° ‘F. being preferred, aviation gasoline or a base stock which may be blended with relatively small quantities, say and at this temperature the heptane is with "drawn through line~36 and-discharged into a sec 15-20% by volume, of alklated isobutane or other .alkylates, to produce a high quality 'avia ondreactor ?ll-containing a catalyst such as chro :tion gasoline. Also, itshould be pointed out that mium oxide supported on activated alumina, the in the dehydrogenation of naphthenes carried out portions being approximately 9 ‘parts by weight of alumina per 1 ‘part of chromium oxide. In .in reactor 20, I may use mixtures of sul?des of stead of using chromium'oxide, molybdenum ox the III and V group elements of the periodic system. ‘ide maybe used. The pressure prevailing in reactor 49 is about It should be noted that one of the ‘major ad 1 ‘atmosphere gauge pressure, and the material vantages of my present invention resides in the feature that less coke is produced in my two-stage is fed to the reactor vat a rate of about 0.5 vol ume of oil per volume of reactor per hour on a process, since I treat the materials under condi cold oil basis. The reaction products contain 40 tions which are less conducive to coke formation. i. -.e., by treating naphthenes and para?ins sepa~ ing toluene are Withdrawn through line 42 and dis charged into a fractionator 44 from which tolu ene‘may be recovered through line 46. The over— .rately. head fraction is Withdrawn, through line 68 and recycled to line 32 for ‘further treatment in re actor '40. The toluene ‘collected through lines 30 and 46 is discharged into equipment (not shown) matter inherent in my invention, except that .It is .my intention to claim all of the subject pm. 9i' excluded by the terms of the appended claim. What I claim is: The method of treating a hydrocarbon oil cracked stock containing ole?ns, naphthenes and paraf?ns and boiling substantially within the ‘to re?ne and purify the same and to produce a ‘product of any desired degree of purity. The "actual ‘puri?cation of this product is well known ’to the prior‘art and need not be described in de tail-herein. > ‘It will '-‘be appreciated ‘that in both reactors ‘20 and-'40, it ‘will be necessary periodically to dis continue the operation to regenerate the cata lyst in‘ said reactors since, due to the reaction, ‘carbonaceous deposits are formed on ‘the said catalyst. The method of regenerating the cata lyst most commonly employed is that wherein it 0 gasoline range, to produce separately aromatic compounds and a gasoline of substantially higher knock .rating than said cracked stock, which com prises vaporizing said cracked stock, passing the vapors through a fractionating zone, removing a ‘light fraction, an intermediate hexane to octane fraction, and .a heavy fraction, said light frac tion and said heavy fraction containing com pounds having relatively high anti-knock value as compared with said intermediate fraction, is vtreated ‘with an oxygen containing gas under 6 0 combining said light fraction and said heavy such conditions of temperature and pressure as ‘fraction ‘to form gasoline, passing said interme to burn the carbonaceous deposits formed there— diate fraction through a heating coil and thence on. This regeneration .method'isalso well known ‘into a hydrogenation ‘zone in which naphthenes ‘to the art. It should be pointed out that in _'are converted into aromatic compounds and ole stead of using :stationary beds of :catalyst inre (3 ° ?ns are saturated, thereby forming a product con actors '20 and 40, a powdered catalyst may be :used and the catalyst may be suspended in ‘the sisting vprincipally of aromatic compounds and 'paraf?ns of 6 to 8 ‘carbon atoms "per molecule, reaction vapors by means already known, during separating the aromatic compounds and the 6 to the reaction period and thereafter separating 8 carbon atom paraf?ns, passing the 6 to 8 car ‘catalyst from the reaction vproducts and return 0 bon atom parafiins through a heating ‘coil and ing the catalyst to the reaction zone. vIn other. thence into a zone where they are converted into Words, any prior known method .of eiiecting con a product composed mainly of aromatics, ‘and tact between catalyst and reactants under reac combining the aromatics produced by the two tion conditions may be used in my improved ‘conversion stages 'hereinbefore recited. process. 17a EDWARD B.'PECK.