US2260945A - Alkylation of hydrocarbons - Google Patents

Description

Oct. 28, 19H. K. KoRPl ET AL ALKYLATION OF HYDROCARBONS Original Filed June 18, 1957 KARL KoRRl ARTHUR R.Go| osav INVENTORS NE YS ATTO of) cm-cmcn-cmHI-moma-cnrcm-C Patented Oct.' 28, 1941 UNITED STATES Y PATENT OFT-ICE I AilKYLATIONzlROCABBQNS Y I Kal'l'Korpi, Redondo Beach, Calif., and Arthur R.

Goldsby, Beacon,v N. Y., assignors to The Texas Company, -New York, N. Y., a'corporatlon of Delaware al application .tune 1s, 1937, serial No.

Origin I 148;978. Divided and this application July 23,v

1941, smal No. masas (ci. iss-1o) This is a division of our oopending application f N antiknock motor fuel may be obtained.

Serial No. 148,978, led fune 18, 1937.

It is well known in the art that aromatic hydrccarbcns, such as benzene, may be alkylated by condensation with olefins in the presence of a suitable catalyst: This reaction apparently is possible because of the reactivity of the hydrogen atoms in the benzene molecule.

Iso-paralns contain hydrogen attached to tertiary carbon atoms whcnpossess unusual reactivity and in some cases even surpass that of the benzene hydrogen. It' has been found that The above of reactions is essentially the union of an olen with an iso-paramn to obtain acting' hydrocarbons of thev proper molecular WdIht, it is possible to obtain products voi! the gasoline boiling range and possessing a high antiknock value. V 'In accordance with the 'present invention,V it is pretm'able to utilize hydrocarbons containing about 4 carbon'atoms whereby a highyield oi productsofpredominantly carbonatoms or octane; is obtained. It has been found, for examphthatbyreacngisobutanewithaClun- 'animated hydrocarbon fraction, a-good yield of high antlknock motor fuel, may be obtained.

stocks oi about 4 carbon atoms because a higher octane product may be produced. the process is .applicable to, and a good product may be obtained from olen stocks of 3 carbon atoms. In

larger quantities of propylene available, and also because a product of lower i peint is obtained. It has been found, for example, that by reacting isobutane with propylene, a good yield of` high` The process may also be Vadapted to umsturated hydrocarbon fractions which v are comprised mainly of a mixture of Gs and C4 hydrocarbons. In some cases this process may be pre- 5 ierred to those in which a fraction of predominantly either 3 or 4 carbon atoms are used, because or the larger quantities of combined C: and C4 available, andalso because the product has a distillation range which requires little light 20 blending vstock to make it suitable for aviation o duced into a reaction vessel; The mixture was -o higher molecular weight iso-paraln. By re-yf' fuel. y

u The invention will be further understood from the following examples of Voperations coming within the scope of the invention.

` Example I Isobutane and concentrated sulfuric acid (66 B.) in the ratio of about 3 parts by volume or isobutane to 2 parts of sulfuric acid were intro- 'aaltated and, during a. period of about 4 hours.

'I parts Aof a C4 stock, consisting-.of a reiinery cracked gas containing about 3.3% Cs, 14.5% '150- butylene and 25.8% normal butylenes, 11% isobutane, 44% normal butano and V1.4% of Cs were slowly added. The reaction was allowed to continue 11/2 hours after the olefin stock was charged. Ordinary temperatures were used and value of 88. Y

- Example Il -ingamixtureof about2partsofisobutaneto3 parts by volumeoi a C4 fraction of cracked gases of substantially the composition given in Ex- Auhnusn it is preferable to uuuzerthe olefin 55 ample I above, were mixed in the raue or about some cases thismay be preferable due to the sulfuric acid (66 ne) and s ci stock contain-- mixture in 3% hours, and the reaction continued an additional 3,0 minutes. The unreacted gases were removed from the reaction vessel and the' liquid products separated from the acid.

The product was substantially the same as that described in Example I above. The yield was about 140% by weight` of the olefin charged, about 74% of the product distilled below 300 F., 20% from 30D-400 F. and the remainder of 6% above 400 F,

Example III Sulfuric acid (400 cc. of 66 B.) is charged into an iron reaction bomb. To the agitated acid in the bomb is charged 362 g. of a mixture, containing 32% propylene and 68% isobutane by weight, at a constant rate in 3 hours. The reaction is allowed to continue ten minutes with agitation. The unreacted gas is removed from the bomb by releasing the pressure and the liquid product is separated from the acid in a separatory funnel. The alkylaton reaction took place at 8595 F. and 60 to 80 pounds pressure per square inch gauge. V

The yield of butane feed product is 166% by weight of the olefin charged. 70% of the product distills below 311 F., 21.4% from 311- 400 F. and the remainder of about 7.3% above 400 F.

The 311 E. P. cut has an initial boiling point of'l37 F., a 10% point of 174, a 50% point oi.' 197 F., a 90% point of 236 F. and an end point of 283 F. by A. S. T. M. distillation, contains less than 0.5% of nsaturation, and hasa C. F.. R. M.

. octane of 81.9.

Example IV volume of olefin per minute for about 170 unit volumes of acid in the alkylaton operation.

the acid in a separatory funnel. The alkylaton reaction took place at 85-95 F. and 50 to 65 pounds pressure' per square inch gauge.

The yield of butane free product is 20% by weight of the olefin charged. 66.8%V of the product distills below 311 F., 22.4%' from 311- 400 F., and the remainder of about 10.8% above 400 F.

The 311 F. cut was combined with the311 F. cut of a similar run to obtain sufllclent material for distillation and C. F. R. M. octane.. The mixture has an initial boiling point of 112 F., a 10% point of 159 F.. a 50% point of 223 F., a 90% point of l268, and an end point of 300 F. by A. S. T.'M. distillation,contains less than 0.5% unsaturatiion and has a C. F. R. M. octane of 81. l

In Examples III and IV it will be observed that the time of contact of the reacting hydrocarbons in the presence ofsthe sulfuric acid catalyst during the alkylaton operation is from 10 mixiutes for the hydrocarbons last introduced to an average for all the hydrocarbons of about 100 minutes. In Examples I `and II an even longer average time ofcontact is used.

Alsoy it will be observed with respect to Example-I above that the rate of olefinV feed to about 30-50 pounds.

In the other examples the rate ofA olefin feed per unit volumeof acid is even less.

Further it will be observed with respect to Example I that the amount byweight of sulfuric acid catalyst in admixture with isoparamn is in excess of the amount by weight of isoparaln. This is also true in the case of Examples II, III and IV.

Also vit will be observed with respectto Example I that the rate of feed to the alkylaton operation of olefin in umts of volume per minute is less thanabout la@ the minimum of units of volume of excess unreacted isoparailinin the reacting mixture.

The process may be operated either as a batch y or continuous operation, but in general the continuous operation-is preferable. In operating continuously, as hereinafter described, the isoparaiiin and olefin hydrocarbons are fed simultaneously into the reaction zone containing the sulfuric acid catalyst, as is likewise true of the batch operations described in Examples III and IV above. Is is desirable'to maintain the isoparaiiin concentration quite high, for example at least equal to the olefin concentration in the mixture, and in some instances from 2 to 3 times the olen concentration. In continuous operation, it is advantageous to keep the initial reaction product between the acid and olefin low. The concentration of the initial products, probably the sulfuric acid esters, can be kept low by The process has been operated successfully at temperatures of 75-90 F. and pressures of y Lower temperatures` from the above, of around 75-80 F., arepreferable but lower temperatures of down to zero or below may be used. It is desirable to maintain sufficient pressure to keep the materials in liquid phase.

The acid is strong sulfuric acid and preferably about 94 to 100% concentration. The ratio of acid to oil may vary considerably. For an oil mixture containing about 20% olefins, for example, the amountof acid should be at least about v5% and may run as high as 100% ,of the oil. In the specific examples set forth above the amounts of acid employed range from about 45% by volume of the oil in Example I to substantially higher proportions in the other examples.

It is' unnecessary to use an unsaturated gas of any particular composition since substantially all the oleiins react. Cracked gases of 3040% olen content are preferable although products containing from 5-50% or more unsaturation may be used. Typical C4 gaseous fractions, for example, run about 15% isobutylene. about 25% normal butylene, about 10-15% isobutane and 4substantial amount of or predominating ,in C4 hydrocarbons, is charged through the line l and forced by the pump 2 through the line 3 into a mixer l. Isoparaiiin hydrocarbons, such as isobutanearechargedthroughthcllnel'andforced bythepumpithrcushthe linelalaointcthc mixerl. Acatalystsuchassulfuricacidisintroduced through the line I and forced by the pump Il throughtheline llintothemixerl. The mixer may be any suitable mechanical means for agitating or effecting contact between theoil andthe acid,suchasmechanlcalmixers. orifice places, and the like. In the mixer 4, it is intended that the acid and hydrocarbons react to produce a union between the olens and isoparaihns to effect reactions of the nature of allcylation. 'I'he reaction products are discharged from the mixer 4 through the line l5, controlled by'valve 'IB to separator I8. In this separator the acid is separated and withdrawn from the bottom thereof through the line 2U. This acid may be recirculated to the mixer, if desired, by means of the line 2| and pump 22. The oil is withdrawn from the top of the separator through the line M and introduced into the neutraliser 25. In this neutralizer the oil is contacted with a neutralizing agent. such as caustic or other l alkaline material introduced through the line 28. The spent caustic, settling out in theneutraliner,

-is withdrawn from the bottom thereof through the line 28. This spent reagent may be recirculated, if desired, by means of the pump 2l. located in the line 39. The oil after contact with the neutralizing agent is conducted from the top of the neutralizing tower 25 through the line I2 and introduced into the settling tower 33, wherein any additional alkali is allowed to settle out and the latter is withdrawn from the bottom of the tower through the ,line'35. This spent neutralizing agent also may be recirculated by means of the pump 33. located in the line 31. Fresh neutralizing agent, if desired, may be introduced through the line 33 in communication with line 31. The treated oil is withdrawn from the top of the settler 33, through the line Il and charged into fractionator 4I provided with a means for heating in the lower portion thereof. such as heating coil 42. `In this fractionator it is intended that a fraction of motor fuel boiling range be vaporized and taken overhead through the line 44 as a distillate fraction while material of higher boiling point than motor fuel is withdrawn from the bottom of the fractionator through the line IB. Vapors are conducted through the line M to stabilizer 43 wherein the motor fuel hydrocarbons are fractionated and separated from hydrocarbons of lower boiling peint than motor fuel. The stabilized motor fuel product is withdrawn from the bottom of the stabilizer through the line 5I while the lighter materials comprising chiefly unreacted hydrocarbons are conducted from the top of the stabilizer through the vapor line ll in which is located condenser 52. condensate formed in the condenser 52 is passed to receiver I3 provided with a gas release line Q4 and a liquid draw-oi! line 55. All or a portion' of the condensate from thereceiv'er 53 may be pumped as a reflux condensate by the pump 56 through the line l1 to the upper portion of the stabilizer. In some instances it may be of advantage to return to the system at least a part of the unreacted gases withdrawn through the gas release line 5I.

Obviously many modifications andvariations of the invention, as hereinbefore set forth, may be made without departing from the spirit and scope thereof, and therefore only auch limitations should be imposed as are indicated in the appended claims. 4

What we claim:

l. A process for the manufacture of normally liquid hydrocarbons boiling within the gasoline boiling range, which comprises reacting low bolling oleiins with a low boiling isoparailln such as isobutane in the presence of concentrated sulfuric acid catalyst while maintaining alkylating conditions, and maintaining in the reacting mixture throughout the entire reaction a substantial molar excess of the iso over the stoichiometrical equivalent monomeric contents of the oleiins, whereby alkylation of the isoparafiin is effected and a substantially saturated liquid reaction product is produced,

2. A process in accordance with claim 1 in which the reacting mixture is maintained substantialLv in liquid phase.

3. A process'in accordance with claim 1 in which the low boiling oleiins comprise the butylenes.

4. A process for the manufacture of normally liquid hydrocarbons boiling Within the gasoline boiling range which comprises simultaneously vfeeding into a reaction zone, containing concentrated sulfuric acid catalyst, a low boiling iso such as isobutane and a low boiling olefin while maintaining alkylating conditions in saidreaction zone, the-feed of the isoparaflln being maintained throughout in substantial molar excess over the stoichiometric equivalent feed of the oleiln. whereby a substantial molar excess of isoparailln to olen is maintained in the reacting mixture throughout the entire reaction. A

5. A process in accordance with claim 4 in which the total quantity of the hydrocarbons present in the reacting mixture is at all times less by weight than the quantity of sulfuric acid catalyst present therein.

6. A process in accordance with claim 4 in .which the reacting mixture is maintained substantially in liquid phase.

7. A process in accordance with claim 4 in which the low boiling olens comprise a butylene.

Aprocess for the manufacture of normally liquid saturated hydrcarbons boiling within the gasoline boiling range which comprises reacting low boiling oleilns with a low boiling iso such as isobutane in the presence of concentrated sulfuric acid catalyst while maintaining alkylatinglconditions, maintaining in the reacting mixture throughout the entire reaction a substantial molar excess of the isoparaiiln over the equivalent monomeric contents of the olefins, and continuing the contact of the hydrocarbons with the acid fora time not less than 10 minutes, whereby alblation of the isoparamn is eifected and a subliquid reaction product is stantially saturated produced.

9. A process for the manufactiu-e of normally liquid'saturated hydrocarbons boiling within the gasoline boiling range, which comprises simultaneously feeding into a reaction zone, containing concentrated sulfuric acid catalyst under alkylatlng conditions. a low boiling iso such as isobutane and a low boiling olenn, the feed of iso being maintained throughout in substantial molar excess over the stoichlometric equivalent monomeric feed of the olefin, whereby a substantial molar excess of isoparamn to olefin is maintained in the reacting mixture throughout `the entire reaction, maintaining the reacting mixture of hydrocarbons and acid in agitation, and continuing the contact of the reacting mixture of hydrocarbons and acid with agitation for not less than l-minutes.

10. In the manufacture of normally liquid hydrocarbons 4boiling within the gasoline boiling range by reacting a low boiling olefin with a low boiling isoparailln such as isobutane in the presence of concentrated sulfuric acid catalyst while maintaining alkylating conditions, the process comprising maintaining a body of concentrated sulfuric acid catalyst in agitation in a reaction zone, supplying thereto a low boiling olefin while maintaining at al1 times a substantial molar ex. cess of the isoparafiln therein, and controlling the rate of supply of oleiln so as not to exceed 1 unit volume thereof per minute for about 170 unit volumes of acid in said reaction zone.

11. A process in accordance with claim 10 in which a molar excess of the isoparaln is fed into the reaction zone simultaneously with the olefin.

12. In the manufacture of normally liquid hy- .tion zone a mixture of concentrated sulfuric acid and isoparailln, supplying olen at a slow rate to the isoparaflin and acid in said zone, and malntaining a substantial molar excess of isoparafn therein at all times, the rate of supply of olefin in units of volume per minute being less than about lo the minimum of units of-volume of excess unreacted isoparaln maintained in said mixture.

13. A process according to claim l2 in which the amount by weight of sulfuric acid catalyst in the mixture with isoparaln is in excess of the amount by weight of isoparailln.

CERTIFICATE 0E CORRECTION. l Patent No. 2,260,9I5. october 28, 19m. KARL KoRPI, ET AL.

It is hereby certified that error appears -in the printed specification of the above numbered patent requiring correction as follows; page 2, first colnnn, line 52, for 20% read l20Z-; and that the' said lLetters Patent should be read with this correction therein that the same may conform to the record of the case in' the Patent Office.

signed and sealed this .201:11 day of January, A. n. 191m.

y 4 Henry Van Arsdale, (S681) Acting Commission-6I of Patents.

Images