US2353731A

US2353731A - Hydrocarbon conversion

Info

Publication number: US2353731A
Application number: US455829A
Authority: US
Inventors: Elmer R Kanhofer
Original assignee: Universal Oil Products Co
Current assignee: Universal Oil Products Co
Priority date: 1942-08-24
Filing date: 1942-08-24
Publication date: 1944-07-18
Anticipated expiration: 1961-07-18

Description

E. R. KANHOFER HYDROCARBON CONVERSION Filed Aug. 24, 1942 July 1s, 1944.v

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' HYDROUMN CONVERSION Elmer-B. Kanhofer, Chicago, Ill.,- assignor to Univernal O il Products Company, Chicago, Ill., a corporation of Delaware This invention relates to a process for the conversion of hydrocarbon oil'into lower boiling hyv drocarbons including gasoline. and more partlcularly to a cracking procs wherein the hydrocarbon oilv may be converted in two closelyinter- A related steps into a motor fuel of very good antiknock quality and high lead susceptibility.

More specifically, this invention comprises a combination process in which hydrocarbon oil the vaporous conversion products into a fraction 'containing relatively olenie gasoline boiling rangehydrocarbons and a heavier fraction con-y taining insuiliciently` converted hydrocarbons,

heating and supplying said fraction containing is first treated in a slurry catalyst cracking step l10 and the light and' heavy products therefrom retreated in a fluidized treating step.

Itisoldinthe artto both in the form of a' slurry and in the form of a .iluidized mass in oil conversion'processes. An-

catalyst cracking and reemploy powdered catalysts relatively olenic gasoline boiling range hydrocarbons Y and heated non-vaporous conversion products containing spent catalyst to a secondary conversion zone containing a" relatively dense turbulent -mass of powdered catalyst wherein they are converted into substantial quantities 'of relatively saturated motor fuel having good anti- `knock quality and high lead susceptibility,v sepa.-

rating and recovering said'motor fuel from insufliciently converted hydrocarbons andreturnother recent development has beenthe process for retreating cracked gasoline in a second' catalytic step to improve the antiknock quality" and lead susceptibility of the motor fuel.. l

In a one stage catalytic' cracking processfthe conditions of operation are usually maintained to produce a highyield of gasoline boiling` range maunderstood, reference is made to'the accompanyterial. -Whenthis is the case, however, a highly Y oleiinic gasollne'is produced. It is'possible to produce a relatively saturated product in -a single stage when operatingl at low temperatures. but

the available charging -stocks suitable for this operation are limited.

In a two step unit a more ilexible operation is obtainable which may be employed to process a. wide range of charging stocks to produceva very high yield of highly saturated product. The improvement which is 'realized in the second or retreating stage of a two step unit is not entirely due to the saturation of the productbut is par- 4tially due to the rearrangement o f the molecules, that is, the formation of branched chain compounds' which have a high antiknock quality.

The features o f my invention make it possible to employ existing thermal cracking equipment to produce aviation grade gasoline with only'a relatively small amount of additional new equipment.

Another feature. of my invention provides for reactivating slurry catalysts employed in the first 1 step of my process. This is accomplished in the regenerator of the second step or iiuidized conversion step. v

In one specic embodiment, my invention comprises heating and supplying a hydrocarbon oil- ....-containing powdered catalyst together with lingsaid lnsuiclently-'converted hydrocarbons to the 'primary conversion zone as hereinbefore set forth.

In order that my invention may be more clearly ingdiagrammatic drawing and the following description thereof. The drawing illustrates schematically in a conventional-side elevation equipment suitable 'for accomplishing the process of my invention.

Referring to the dr'awing, the rawoilgto be l converted is introduced fo the system through line i; suitable charge pump 2 and valve 8. This `oil may be diverted all or in part by means of line l '4 and valve I to absorber l wherein the oil may be employed to scrub catalyst nes from combustion gases produced as hereinafter set forth. Part or all of the charging oil may be diverted around absorber i by means of by-pa'ssgline I and valve In .caseswherein an insuiiiclent quantity of' catalyst is ,picked up in absorber 1, additional vcatalyst may be introducedinto the oil in line 1 by 'means which will hereinafter4 be described.

The quantity'of catalyst to be entrained inthe charging oil will be dependent upon the particular charging stock to be converted and will range heated insufhciently converted hydrocarbons K formed as hereinafter set forth to a primary conl -version zone, separating the non-vaporous conversion products containing spent catalysts `Vliti from about .1 of 1% catalyst by weight of oil up to about 10% by weight of oil or more depending jupon thel capacity of the oil to form a slurry with the catalyst.

The charging stock including the entrained catalyst is directed by means of line 1 through pump ill interposed inline l and valve .i I to heating coil l! disposed within heater I3. Within this coil the oil will be heated to a cracking temperature of from about 800 to about 1150 F., -or more, but preferably within the range oi' from about 90)q to about 1050' and-will normally be maintained at a pressure of from about atmospheric to about 400 pounds per square inch or more. At these conditions relatively olefinic gasoline is produced. Coil I2 will normally be of a length to give the oil sufficient time for conversion, but in some cases it may be desirable to include a reaction chamber for additional cracking time. This reaction chamber, however, is not essentlaltoithe process so inorder to simplify the da'wing, it" has not been included therein.

'I'he oil after being maintained for a suilcien't time at the desired temperature is directed .by means of line I4 through pressure reducing valve I5 to ilash chamber I6. 'Ioarrest any -further suitable cyclone separator (or a plurality of sepundesired cracking a suitable 'quenching oil may be introduced into line I4 by means of line 8| controlled by valve 62. In this ash chamber, the lighter converted materials will be vaporized and passed overhead throughline I 1 to frac tionator I8v and the-heavier unvaporized materials containing catalyst will -settle and be diy verted by means ofline I8 and valve 20 to cooler 2| wherefrom by means of line 22 they willbe directed to-receiver 23. A l I In fractionator I8 the -vaporous conversion products from ash chamber-l6will be separated into an overhead cut containing gasoline which will be diverted by means of line 24 and valve 25 through condenser 26 and line 21 to receiver 28.

` The unliqueed material may be vented from the system atthis point by meansof line 29 and valve 30. The liquefied portion o f the oil-charged arators) '50 and line 5I to fractionator 52. In cyclone separator 50,- additional entrained catalyst will be separated from the eilluent stream and be directed by means of line 53 back into the relatively dense zone within reactor 41.

In fractionator 52 the converted materials of the desired boiling range will pass overhead through line 54. and valve 55 to additional separation equipment depending upon the nal boiling range desired. The heavier and insuilciently l converted materials will be withdrawn from the bottom of fractionator 52 by means of line 56 and valve 51 to be recycled to the slurry cracking zone, or this material may be withdrawn from the system by means of line 58 and valve 59.

4In Areactor 41 the pressure maintained will preferably b e within, the range of atmospheric to approximately 100 'pounds per square inch to receiver 28 is withdrawnthrough line 3| and A pump 32 interposed in line3I. A--portion of this material wil1 be returned by means of line -33 and -valve 34 to thetop of fractlonator I8 to serve as a reflux, and thebalance of the'material will be directed by means of line 35 and valve 36 to line 22 wherein it will be mixed with the unvaporized material containing catalyst which was separated from the lighter materials in flash chamber I6. This stream of admixed heavy ma- A terials, catalyst and lighter overhead materials from fractionator I8 isthen directed to receiver 23.

. The'bottom cut from fractionator I8 may be recycled to heating coil I2 by means of line 31, valve 38, line 1 and pump I0, or in some cases it may b'e withdrawn from the system by means ofline 39 and valve 40.

From receiver 23 the commingled heavy. and lighter materials containing catalyst will be directed by -means of. line 4I, pump 42 interposed in line 4I -and valve 43 to the heating coil 44 located in heater 45. From heating coil 44 the oil-will be directed by means of line 46 to reactor 41. The temperature of the oil leaving heater will be such that a. temperature within the range of about 750F. to about 1000 F. or preferably in the range of about 800 to 950 F is maintained in reactor 41. Regenerated catalyst is introduced into line 46- as hereinafter described:

Within reactor 41, the mass of catalyst is maintained in a turbulent state by the action of the uid reactants introduced through line 46. A perforated distribution plate 48 may be disposed in the lower part of reactor 41 to 'aid in the *uniform distribution offreactant materials introduced thereinto. The catalyst particles in reactor 41 are. maintained in a turbulent state by vthe upward.1iow of reactant materials which have a velocity not quite sucient ;to overcome all the gravitationalforces on thecatalyst parand`l therate of oil charged per hourper unit weight of catalyst in the reactor, that is weight space velocity, willbe onthe order of approximately .25 to 6, but preferably within the range ol .5 to 2. The conditions at which reactor 41 ismaintained are such that the olenic gasoline from -the rst step is converted into a relatively saturated product.

'The catalyst in reactor 41 will becomev contaminated by carbon and hydrocarbonaceous materials andin my process the contaminated catalyst may 'be continuously withdrawn from reactor 41 by means of line 60 and valve 6I. Flue gases or other inert gases containing a regulated proportion of oxygen or air is directed throughA line 62 and valve 63 and will pick up the contaminated catalyst from line6Il and carry it linto regenerator 64 wherein the carbonaceous .materials will be burned from the catalyst. The

air introduced through line 62 may be regulated so that the combustion' within regenerator 64 will `be maintained within a temperature range of approximately 1000 to 1300 F., but preferably within the range of 1050 to 1200 F.

Regenerator 64 will contain a relatively dense.

phase separated by an interface indicated .by dottedl line 88 from a lighter phase in the upper portion-cf theregenerator. This upper portion -will actas a settling space forl entrained catalyst particles and the eilluent combustion gases will leave thev regenerator by means of line 66 and pass through cyclone separator 61 and line 68 to the aforementioned absorber 6. Catalyst particles entrained in the stream passing .through line 66 will be separated in separator 61 and will be returned by means of line 69 to the 'dense phase inv regenerator 64. Finelydivided catalyst particles remaining in the effluent gas stream will be scrubbed therefrom by the vraw oil.charge in absorber 6 and the substangases will leave the system tially catalystr free by means of line and valve 86.

. The regenerated catalyst. particles will be withdrawn from regenerator 64 by means of line 1I! and valve 1| and introduced into the heated reactant stream in line 4l. 'I'he ratio by weight of catalyst: oil in line 46 may be regulated by means of valve 1| and normally will be within the range ofv .25 to 25, but preferably will be Within the range of 2 to 10. When it is desired to 'include more Ptalys't in the raw oil than is l picked up in absorber 6, additional catalyst may be withdrawn from regenerator 64 by means of line. 12 vcontrolled by valve 13. As is the case in reactor 41, a perforated plate 65 may be dis` posed in the lower portion of regenerator 64 to aid in the uniform distribution of incoming materials.

Catalyst make-up may .be introduced 'into the system through line 83 and valve 84 to line 62. The contaminated catalyst passing through I line 60 may be stripped of vaporizable hydrocarbon materials by means of steam or other inert fluids introduced through line 14l and valve 15, and the regenerated catalyst leaving regenerator 64 b'y means of line 10 and 12 `may be stripped of air by means of suitable `inert iluids introolefln'ic gasoline, separating the resultant conversion products into a vapor fraction containing the oleiinie gasoline and a liquid fraction powdered cracking catalyst to a cracking temf' perature for a time period sufiicient to formA containing the powdered catalyst, fractionating l said vapor fraction to separatethe oleflnic gasoline, introducing the olenic gasoline and said fraction containing the powdered catalyst into Ia zone containing a. bed of powdered cracking catalyst at a rate such that the bed of catalyst is maintained in a state ofvmotion and therein treating the gasoline fraction underconditions regulated to produce a substantially olefin-free gasoline while simultaneously separating catalyst from said fraction as the latter passes in contact with said bed of catalyst.

2. A conversion process whichcomprises subjecting a hydrocarbon oil containing suspended powdered cracking catalyst to a cracking ternperature for a time period sumcient to form olefinic gasoline, separating thev resultant conversion products into a vapor fraction containing the olenic gasoline and a liquid fraction containing the powdered catalyst, fractionating said vapor fraction to separate the olefin-ic gasoline, combining the oleiinic gasoline with said said bed of catalyst.

fraction containing the powdered catalyst, adding additional catalyst to the mixture, introducing the resultant mixture into a zone containing' a bed of powdered cracking catalyst at la rate such that the bed of catalyst ismaintained in a state of motion and therein treating the gasoline. fraction under conditions regulated to produce a substantially olen-free gasoline while simultaneously separating catalyst from said fraction as the latter passes in contact with 3. A conversion-process which comprises subjecting a hydrocarbon oil containing suspended Apowdered cracking catalyst to a cracking temperature for a time period sufcient to form oleiinic gasoline, separating the resultant conversion products into a vapor fraction containing the oleflnic gasoline and a liquid fraction containing the powdered catalyst, 'fractionating said vapor fraction to separate the oleflnic gasoline,

\ combining the oleflnic gasoline with said fraction containing the powdered catalyst, heating the mixture to a temperature of from about 750 to about 1000?l F.,- adding-additional catalyst to lthe thus heated mixture, introducing the resultant mixture' into a zone containing a bed of powdered cracking catalyst at a rate such that the bed of catalyst is maintained in a state of motion and'. therein treating' the gasoline fraction under conditions regulated to produce a substantiallyolen-free gasoline while simultaneously separating catalyst from said fraction as the latter passes ,in contact with said bed of catalyst.

4. `A conversion process which comprises sub- Jecting a hydrocarbon oil containingA suspended powdered cracking catalyst to a cracking temperature for a time period sufiicient to form oleflnic gasoline, separating` the resultant consubstantially olen-free gasoline and to form reversion products into vapor fraction containing the oleflnic gasoline and a liquid fraction containing the powdered catalyst, fractionating saidvapor fraction to separate the oleiinic gasoline, combining the olefinic gasoline with said fraction containing the powdered catalyst, heating the mixture to a temperature of from about 750 to about 1000 F., adding additional catalyst to the thus heated mixture, introducing the resultant mixture into a zone containing a bed of powdered cracking catalyst at a rate such that? the bed of catalyst is maintained in a state of motion and therein treating the gasoline fraction under conditions regulated to produce a substantially olefin-free gasoline while simultaneously separating catalyst from said fraction as vthe latter passes in contact with said bed of catalyst, withdrawing resultant vaporous conversion products from said zone, and separating entrained catalyst therefrom, fractionating said vaporous conversion products ,to separate the flux condensate and supplying the latter to the first-mentioned cracking step.

ELMERv R. .KANHOFER.