US2145025A - Gasoline manufacture with byproduct recovery - Google Patents

Description

R. M. ISHAM E T A1. 2,145,025

GASOLIUE MANUFACTURE WITH BY-PRODUUT RECOVERY Jan 24, 1939.`

Original Filed Oct.- 30.. 1923 Sheets-Sheet Jan. 24, 1939. R. M. lsHAM E-r AL 2,145,025

GASOLINE ANUFACTURE WITH BY-PRODUGT RECOVERY Original Filed Oct. 30, 1923 2 Sheets-Sheet 2 Patented Jan. 24, 1939 UNITED; STATES 4G'Asonuva MANUFACTURE wrm BY- Paonuc'r RECOVERY Robert M. Isham, Okmulgee, Okla., and Henry N. Lyons, Maplewood, N. J., assignors, by mesne assignments, to Power Patents Company, Jersey City, N. J., a corporation of Maine Application October 30, 1923,

Serial No. 671,645

Renewed December 18, 1935 38 Claims.

Our invention relates primarily to the production of gasoline and of alkyl sulphates.

The production of cracked gasoline as commonly practiced heretofore has involved a careful and expensive chemical treatment of the distillate including theuse of sulphuric acid followed by redistillation to obtain a. product having the desired characteristics. The distillate so obtained by the ordinary process has not, however, been suitable for use for blending with straightrun or uncracked gasoline without one or more redistillations.

It is also known to treat the tail gas from the cracking stills with sulphuric acid in the presence of an inert menstruum such as gas oil to form mixed alkyl sulphatesfnthe mixture consisting principally of acid alkyl sulphates. These sulphates are afterward hydrolyzed to produce alcohols.

It is the principal object ci our invention to so combine the production of cracked gasoline and alkyl sulphates so as to improve the process of producing cracked gasoline and the product itself as well as the process of producing alkyl sulphates. A

Other objects and advantages of our invention will appear to those skilled in the art from the following description taken with the accompanying drawings in which Fig. 1 is a diagrammatic view of an apparatus according to our invention adapted to carry out our improved process;

Fig. 2 is an elevation of the acid absorption apparatus shown in Fig. l. r

In thedrawings 4 is a still which may be of an convenient type of pressure still having an inlet B for oil to be treated and a vapor outlet through pipe 8. The boiling point of the oil forming the raw material of the present process is relatively high compared to the boiling point of the product K y obtained in greatest volume, such product being motor spirit or gasoline material. Still 4 is normally heated to a temperature high enough to crack the oil being fed in at 6 by rieans of a ame in furnace l0. Cracked vapors passing out of still 4 by line 8 enter a dephlegmator i2 wherein certain of the heavy vapors are condensed'and flow back into still 4 through a trapped line I4.`

'I'he still 4 is preferably so operated that the vapors leaving the top of the dephlegmator I2 have a temperature of about 520 F. Vapors leave the upper part'of dephlegmator l2 through pipe I 6 having a pressure reducing valve i8 therein, the pipe I6 leading' to a condenser coil 20. The valve 'I8 may be so adjusted that the pressure in the condensing coil 20 is reduced substantially to atmospheric. uid in the tank 22 surrounding the coil 20 is maintained at such a temperature that the coil itself is normally between 135 F. and 150 F. when o p- According to our invention the liq- (Cl. 26o- 460) erating at atmospheric pressure. From coil 20 liquid and uncondensed gases pass by pipe 24 to a separator tank 26 wherein pressure benzine separates from the vapors and gases and is taken oi through pipe 28. The uncondensed vapors andy gases iiow out of the tank 26 by pipe 30 to a comprcssor 32 which is connected by pipe 34 to a cooling coil 36.v The pressure produced by compressor 32 preferably is so related to the temperature in the cooling coil 36 that the ordinary gasoline material, as well as unsaturated hydrocarbons such as amylene and higher olenes areA con- ,densed in coil 36. From the cooling coil 36 the liquids and gases pass by pipe 38 to a reaction tower 40 within which the gasoline and uncondensed gases flow upwardly in contact with a down-coming stream of concentrated sulphuric acid introduced into the upper end of tower 40 by pipe 42. In case, however, it is desired to operate condenser 20 under pressure valves 3l and 33 in pipes 30 and 34 respectively are closed, valve i8 is opened and the gases and vaporspassed directly from separator tank 26 through pipe 36, pipe 35, valve 31 and pipe 34 to cooler 36. Moreover, the pressure on the gas and condensed Vapors entering the absorber may only be that necessary to force this material through tower 40. This, of course, varies with the height of the tower. f 4

In the processes which have been used heretofore a large loss lhas been encountered, due to the polymerization of the oleilnes to form tarry oils which consumed a large percentage of the olenic content of the gases. the polymerization which occurred was due prin-l cipally to the condensing action of the acid upon the olenes ofthe gas. It has been discovered, however, that a large amount of polymerization loss is due to decomposition and polymerization of the acid alkyl sulphates. This decomposition oi. the acid sulphates is Aexaggerated where the temperatures are comparatively high. In the pres- It was believed that ent invention a comparatively small loss due to polymerization of the olenes is encountered. To Y accomplish this, separate zones are maintained in the acid absorbing tower 40 whereby the acid liquors are held in a condition unfavorable to the polymerization of the olenes. Cold concentrated sulphuric acid (1.84v gravity) is introduced into peratures of the liquid suillciently low to prevent polymerization of the olenes. The rate of reaction between concentrated sulphuric acid and the oleiines is very rapid and the heat of reaction is quite high, so that the liquid will soon become heated to a temperature where polymerization sets in if cooling is not employed. The rate of reaction between the olenes and the acid alkyl sulphates is very rapid, but the heat of reaction is much less than that' of sulphuric acid, so that less cooling is required to maintain the liquor at a temperature below the polymerization point in the zone where the alkyl acid is reacting. The cracked oil gas containing the oleiines iscooled before it is introduced into the tower, and this cooled gas is introduced into the zone consisting principally of dialkyl sulphates and acid alkyl sulphates. In this zone the higher boiling point olefines principally are reacted upon by the acid alkyl sulphate, and as the gas progresses upwardly through the absorber, the lower boiling point olenes are absorbed. At the time the gas is passed through the mid zone in which the acid alkyl sulphates prevail, there is a comparatively small amount of olenes in the gas which will be reacted upon by the concentrated sulphuric acid at the temperatures prevailing in the absorber. In this upper zone where the concentrated acid prevails, the last portion of the absorbable olefines higher in the oleiine series than ethylene is absorbed and the acid is used for the purpose of removing from gasoline, the dialkyl sulphates which are dissolved therein as it passes upwardly through the absorber in the path of the gas. Concentrated acid acts either to dibsolve or to break down the dialkyl sulphates to form acid alkyl sulphates, and the acid and acid alkyl sulphates are .substantially insoluble in the gasoline; therefore by the time the gasoline has passed upwardly through the concentrated sulphuric acid all of the dialkyl sulphates will have been removed therefrom.

The cooledcracked gas is introduced into the lower portion of the absorbing tower 40 through a pipe 38 and uniformly distributed throughout the area of the tower bya perforated ring 39 (Fig. 2).

The cooled gas contains a considerable quantity of gasoline or similar hydrocarbons, and as the gas passes upwardly through the absorber 40 in contact with the cooling coils, the more volatile.

hydrocarbons therein are condensed and mixed with the gasoline material which enters the tower 40 in a liquid state. This gasoline or hydrocarbon menstruurn being lighter than the acid, tends to move upwardly through the tower with the gas'so that there is a movement of gas and liquid upwardly through the tower, and a countercurrent movement of 4the sulphuric acid, the acid alkyl sulphates andthe dialkyl sulphates downwardly through the tower. The mixture of sulphuric acid, acid alkyl sulphates, dialkyl sulphates, and gasoline substantially lls the tower from top to bottom. As the gas passes through the' tower in contact with the hydrocarbon menstruum which is a high gravity gasoline, it may be that the oleflnic content oi' the gas is absorbed in the hydrocarbon mass and that the reaction between the acids and the olenes is a reaction between the oleiines absorbed in the hydrocarbon mass and the acids. Regardless of the mechanics of the reaction, repeated experiments. show that the hydrocarbon liquid materially assists in an eillcient'absorption of the absorbable oleflnes in the gas and minimizes the polymerization of the oleilnes.

arge (PbO) in 1000 parts of water.

The absorption tower 4i) is preferably cooled by means of brine and the temperature in the tower is purposely maintained so lowpreferably between 32" F. and 40 F.-that substantially no ethylene is absorbed by the acid. It is important that the low temperatures are maintained in the lower part or the lower zone of the absorber when the raw gas is introduced but temperatures up to 60 F. may be used in the upper zone of the absorber. These temperatures, however, are very suitable for the absorption of olefines containing more than two carbon atoms so that a considerable` part ofthe absorbable olefiuic materials of the gases and gasoline except ethylene are absorbed by the time the gasoline and gases leave the absorber 40. The absorption in the tower is preferably made underpressure because it is found that the use of pressure gives much greater capacity and a smoother and more efficient absorption. Pressures of fromv75-l00 pounds per square inch give the best results for absorption.

Gasoline and unabsorbed gases including ethylenc, pass out of the top of the tower 49 through pipe 46 into a trap 48 in which the condensed gasoline separates from the gases. The gasoline passes to the bottom of the trap through pipe 50 and the gases pass out through elbow 5| (Fig. 2) and thence out of the trap through pipe 52. A certain amount of sulphuric acid is carried over from tower 40 to trap 48 by entrainment in the gasoline and gas and this acid separates out in trap 48 and is permitted to flow back into the tower 40through pipe 54 connecting the bottom of trap 48 with the tower, preferably at about the fifth plate from the top of the tower.

The gasoline passing out'of trap 48 through pipe 56 is doctor sweet and needs only washing with water followed by a light neutralization with alkali carbonate or the like to be ready for use. A gasoline is considered doctor vsweet if vno vislble reaction is observed when two volumes of gasoline are shaken'with one volume of doctor solution. Where a visible reaction occurs between" the solution and the gasoline the test is deemed positive, as a result of which the gasoline is considered sour, The doctor solution to be used in the test may be made by dissolving 125 parts by weight of sodium hydroxide and 60 parts of lith- It is to be understood that the invention is not limited to the use of any particular doctor solution. As illustrated in the drawings, pipe 56 preferably connects with an agitator 58 in which the gasoline material is washed with water to remove some acid and to improve the color after which it is neutralized and drawn off through pipe 60 to storage. This gasoline may be used for blending with straightrun" gasoline as is usually done with cracked gasoline. It has a gravity of about 65 Baum (liquid scale), can be used alone as a motor fuel and will hold a permanently good .color and odor which is not ordinarily the case with cracked gasoline.

The construction of the absorption tower 40 is illustrated in some detail in Fig. 2. 'I'he tower may conveniently comprise a plurality of bubble plates 6262 of known construction, permitting the light liquids and gases to ilow upwardly and countercurrent to the heavy acid, alkyl sulphuric acid and alkyl sulphates which flow to the bottom aimons er products are 'forced to pass into the heavy liquids held on the upper faces of plates 62. The heavy liquids pass downwardly through the plates 82 by means of pipes 68, 68 so arranged that their upper ends are positioned at the desired level of the heavy liquids on the upper faces of plates 62 and their lower ends dip into the layer of heavy liquids held on plates below the ones to which the pipes are fixed, thusl preventing the gases and light liquids from passing up through them. Preferably a cooling coil 69 is located in each section of the tower. Brine for the cooling coils 69 is conveniently introduced through a header 10 connected to individual coils 69 by means of,

valved connecting pipes 12. Similarly the brine may be discharged from coils 69 through valved drawoff pipes 14, 14 into a discharge header 16. The cooler 36 is preferably supplied with brine from header 10 through connection 11 (Fig. 1).

Immediately below the level at which the gases.

and gasoline are introduced into the tower through the pipe 38 is a partition or diaphragm 18 which forms the bottom of the absorption zone of the tower. The portion of the tower below the plate 18 comprises a separating chamber 80 which is arranged to prevent agitation of the liquid therein so that the dialkyl sulphate Will, separate from the gasoline. The heavy liquids pass down through plate 18 by pipe 82, the upper end of which maintains asuitable level of heavy liquid above plate 18 so that the incoming material from ring 39 is thrown immediately into contact with the heavysulphate liquids. However, a certain amount of gasoline is carried down through pipe 82 by the sulphate liquids and the outflow from the chamber 80 is so regulated that such gasoline material has opportunity to separate from the sulphate liquids in this chamber and ow back upwardly through plate I8 by means of pipes 84, 84 fixed to' plate 18 and extending upwardly therefrom above the readily hydrolizable.

tower 40 are to be converted into alcohol, the.v

liquid containing them is taken off through pipe 86 and passed through a mixing box 88 and a trapped pipe 90 into a hydrolizng tank 92. In the tank 92 water is added to the sulphate liquids for the purpose of hydrolizing the alkyl sulphates to alcohols and sulphuric acid. However,

we have found that the dialkyl sulphates drawny oi from the separator are not readily .hydrolized and consequently we prefer to introduce additional sulphuric acid into tank 92 at the time of adding the water for hydrolizing purposes. 'I'he added acid either dissolves or converts the dialkyl sulphates to acid sulphates which are We prefer to add the water and acid to them in the form of dilute acid which may conveniently be introduced through pipe 94 into a vapor trap 976 whereby the dilute acid catches and lwashes back any vapors which may rise from the top of tank 92 -through pipe 98. The water or dilute acidthen passes from vapor trap 96 to the mixing box 88 through. pipe I 00. In case it is desired to use concentrated acid to change the dialkyl sulphates to -acid sulphates such concentrated acid may be added t0 the box' 88 through pipe |02, the water necessary for hydrolization being added through pipe 94 and only so much being used as to prevent escape of vapors through trap.96. The acid alkyl sulphates containing more than two carbon atoms are readily hydrolized and the mixture of alcohols and weak acid from tank 92 is drawn 'oi through a trapped pipe |04, and passed through a serlesof stills |06, |06, each having a heating coil |01 therein. The alcohols are distilled oi fromthe acid in stills |08.

Although all but a small percentage of the alkyl sulphates formed in tower 40 are recovered as su'ch and may be converted into alcohols, a certain percentage of these substances polymerize and absorb or mix with some gasoline and sulphuricV acldtoform a diiiicultly separable mixture or emulsion and this mixture, consisting principally of polymerized olenesderived from the alkyl sulphates, collects as a top layer in the hydrolyzing tank 92 and is drawn off through trapped :pipe |08.

Dilute acid from stills |06 `accumulates in sump |09 and may be used in the hydrolyzing tank 92 as above mentioned, or may be concentrated and returned to the process.

Alcohol vapors from stills |06 pass by pipes ||0, ||0 into vapor line ||2 and through line ||2 to a condenser |.4. We have found that the mixture of heavy alcohols coming from con-` denser ||4 is difiicult to lter unless diluted. Water for this purpose is added preferably by a pipe ||6 connecting with the condenser ||4 r on the vapor side thereof, whereby the water for diluting vpurposes assists ln condensing the alcohols. When diluted with water the mixed alcohols from condenser ||4 are ltered through filter ||8 containing sawdust or the like filtering medium.

While-we have described our improvement above in a specific manner said description is not to be `consdered limiting.

It will be understood. moreover that wherever the phrase alkyl sulphate" is used herein, either in the description or claims, that both dialkyl and acid alkyl sulphates are included.

It is evident that our invention avoids scrubbing the tail gases with wash oil, as is usually done because the normally Lrecoverable light gasoline constituents are condensed at the pressures and temperatures prevailing in condenser 36 and tower 40. It also avoids re-running all but a small amount of the cracked condensate. Ordinarily. the entire condensate from a cracking still is obtained in the form of. a' pressure benzine needing to be rerun to obtain the gasoline material in a vform suitable for lchemical treatment. According to our invention, however, only the material separating out in tank 28 needs to be rerun. It is evident also that we may run the material from the dephlegmator to the reaction or absorption'towerA 40 without separating out a pressure benzine. -While the omission of the step of separating out the benzine would, in our opinion, decrease the commercial eiilciency of our process and apparatus, our process would still retain many advantages if this step were omitted and it will be understood -that many such changes and variations may be 1. The method of treating vapors from cracked hydrocarbon oils, which comprises condensing a pressure benzine out of the cracked vapors, cool- 'ng the remaining vapors, sulphating the olefins contained in the cooled material with sulfuric acid under` cooling conditions at a temperature below 60 F., and separating out a doctor sweet gasoline from the sulfuric acid residue containing alkyl sulfates.

2. The method of producing a doctor sweet gasoline from vapors of cracked hydrocarbon comprising separating out a benzine yfrom said vapors, condensing the gasoline material in said vapors, simultaneously sulphating said condensate and the uncondensed gases and vapors under cooling conditions at a temperature below 60 F. with concentrated sulphuric acid, and separating the gasoline from the gases and alkyl sulphates.

3. The method of forming alkyl sulphates comprising passing a mixture of saturated and unsaturated hydrocarbon liquids, vapors and'gases in counter current relation to concentrated sulphuric acid under cooling conditions at a temperature below 60 F., and separating-the alkyl sulphates from the gases and gasoline.

4. The method of making alcohols from dialkyl sulfates, which comprises mixing the dialkyl sulfates to be treated with sulfuric acid and thereby converting said sulfates to acid alkyl sulfates and hydrolyzing the resulting acid alkyl sulfates.

5. The method of making alcohols from dialkyl sulfates, which comprises adding suicient dilute sulfuric acid to said sulfates to dilute and to convert them to acid alkyl sulfates, and then hydrolyzing said acid alkyl sulfates by heating them in the presence of water.

6. `The process comprising dephlegmating cracked vapors of hydrocarbon oils, cooling the vapors and gases to a temperature of between F. and 150 F. to separate out a pressure benzine, cooling the remaining vapors and gases to condense the hydrocarbons ordinarily contained in gasoline and treating the mixture of condensate, vapors and gases with concentrated sulphuric acid under cooling conditions below a temperature of 60 F.

7. The process of rening cracked hydrocarbon oils, which comprises dephlegmating such cracked oil vapors and gases, thereafter cooling the vapors and gases remaining uncondensed to condense the hydrocarbons ordinarily contained in gasoline and treating the resulting condensate, vapors and gases with concentrated sulfuric acid under cooling conditions at a temperature below 60 F. which is suiciently low to prevent substantial polymerization of the unsaturated hydrocarbons contained in the condensate, vapors and gases being treated.

8. The process comprising dephlegmating cracked vapors and gases of hydrocarbon oils under pressure to throw back heavy liquids and to reduce the temperature of the vapors and gases to about 520 F., reducing the'pressure of the vapors and gases to approximately atmospheric, cooling the gases and vapors to a temperature of between 135 F. and 150 F. to separate out a pressure benzine, compressing and cooling the remaining gases and vapors to condense ordinary gasoline material therein, and treating the mixture of condensate, vapors and gases Y with concentrated sulphuric acid under pressure and cooling conditions at a temperature below 60 F.

9. The process of recovering low boiling point hydrocarbons from the vapors of cracked hydrocarbon oil, which comprises passing such vapors to a condenser wherein the temperature is so controlled that vapors condensible at temperatures below to 135 F. remain uncondensed, cooling and condensing portions of the remaining low boiling point vapors and passing the resulting mixture of vapors and condensate at a temperature below 60 F. through a contact zone in intimate contact with sulfuric acid, alkyl sulfuric acid and dialkyl sulfates.

10. The process of recovering low boiling point hydrocarbons from the vapors of cracked hydrocarbon oil, which comprises passing the vapors through a condensing zone wherein the temperature is maintained such that vapors condensible at temperatures below 150 to 135 F. remain uncondensed, further cooling the vapors remaining uncondensed in said condensing zone to condense hydrocarbon constituents thereof, and passing the condensed hydrocarbons. together with any vapors still remaining uncondensed into contact with sulphuric acid maintained at a temperature below 50 F.

11. The process for recovering low boiling point hydrocarbons from the vapors of cracked hydrocarbon oil, which comprises passing the vapors through a condensing zone wherein the temperature is maintained such that the vapors condensible at temperatures below 150 F. remain uncondensed, cooling the vapors leaving the condensing zone to condense additional quantities of hydrocarbon constituents therefrom, and passing the condensed hydrocarbons together with any remaining uncondensed vapors into intimate contact with an acid menstruum comprising sulfuric acid, and alkyl sulfuric acid maintained at a temperature below 60 F.

12. A process of recovering low boiling point hydrocarbons from the vapors of cracked hydrocarbon oil which comprises passing such vapors through a condensing zone in which a temperature is maintained such that vapors condensible below 150 F. remain uncondensed, condensing additional quantities of hydrocarbon vconstituents from the remaining vapors, passing the resulting condensate through an absorbing zone in contact with sulphuric acid maintained at a temperature below 50 F., and separating the liquid hydrocarbon material from the acid treating medium.

13. A process of recovering low boiling point hydrocarbons from the vapors of cracked high boiling point hydrocarbons, comprising passingA the vapors to be treated through a condensing zone wherein the temperature is maintained at a point sufliciently high that the vapors of gasoline leave the condensing zone uncondensed. sulphating olen'constituents of the remaining vapors under pressure at a temperature below 50 F. in contact with the gasoline constituents condensed from the said remaining vapors, by passing the same in contact with sulphuric acid.

14. That step in the process of producing gasoline, which comprises treating cracked hydrocarbon oil vapors and gas containing substantially no higher boiling point ,vapors than gasoline in an absorber which is cooled to a temperature below 60 F. which is suiiiciently low to condense gasoline hydrocarbons, introducing sulphuric acid into contact and separately removing the gasoline and sulphated liquor from the absorber. I

15. In the process of recovering olefin hydrocarbons from cracked hydrocarbon oil gas containing absorbable olefins, the steps which comprise passing the gas from whichthe olefins are to be recovered in intimate admixture with liquid gasoline containing unsaturated hydrocarbons into intimate contact with a sulfuric acid absorbing menstruum maintained at a temperature below 60 F. which is sufciently low to prevent substantial polymerization of the unsaturated hydrocarbons contained in the gasoline. 16. In the process of recovering olefin hydrocarbons from cracked hydrocarbon oil gas containing absorbable olens, the steps which comprise passing the gas from which the olefins are to be recovered in intimate admixture with liquid gasoline containing saturated hydrocarbons into intimate contact with a sulfuric acid absorbing menstruum maintained at a temperature below 60 F. which is sufliciently low to prevent substantial polymerization of the unsaturated hydrocarbons contained in the gasoline.

17. The method of forming alkyl sulphates comprising passing a mixture of saturated and unsaturated light hydrocarbon liquids, vapors and gases, containing nothing substantially heavier than the heavier fractions of gasoline,` in countercurrent relation to concentrated sulphuric acid under pressure andcooling conditions at a temperature below 60 F. which is sunciently low to prevent substantial polymerization of the unsaturated hydrocarbons contained in said mixture, and separating alkyl sulphates from the gases and gasoline.

18. The process of treating and refining vapors and gases from a pressure hydrocarbon oil cracking zone, which comprises reducing the pressure on the vapors and gases from the cracking zone to approximately atmospheric pressure, cooling the vapors and gases toa temperature of from 1357 F. to 150 F., compressing and further cooling the remaining gases and vapors to condenseordinary gasoline material therein, and treating the resulting mixture of condensate, vapors and gases with concentrated sulfuric acid underpressure and cooling conditions at a temperature below 60 F. which is sufliciently low to prevent substantial polymerization of the unsaturated hydrocarbons contained in the materials'being treated.

19. The process of treating gases and vapors of cracked hydrocarbon oil, which comprises cooling the gases and vapors under superatmospheric essure to condense ordinary gasoline material contained therein, and treating the resulting gasoline condensate with concentrated sulfuric acid under superatmospheric pressure and cooling conditions at a temperature below 60 F. which ls sufficiently low to prevent substantial polymeri. zation of unsaturated hydrocarbons contained in the gasoline.

20. The process of producing a motor fuel and alkyl sulfates from petroleum oils, which comprises subjecting the vapors from a petroleum oil cracking step to fractional condensation whereby a benzine distillate is produced, subjecting'the benzine' distillate to the action of concentrated sulfuric acid ata temperature below 60 F. which is sufficiently low to prevent substantial polymerization of unsaturated constituents contained in thedistillate whereby portions of the olefin content of the distillate are absorbed and converted into alkyl sulfates, and separating out the resulting refined distillate as a gasoline motor fuel.

- ing unsaturated hydrocarbons, which comprises 21. The process of producing a motor fuel and alkyl esters from cracked petroleum vapors, which comprises cooling the vapors containing the lighter fractions of the petroleum to produce a benzine or crude naphtha condensate containing substan- 5 'rated'and unsaturated hydrocarbon liquids, va-

pors and'gases for the production of sulphated hydrocarbon compounds and a motor fuel which comprises passing such mixture through a reaction chamber in contact with sulphuric acid maintained at a temperature below 60 F. and of gradually increasing concentration, thereby removing from said mixture th more reactive conf stituents as said mixture advances through said chamber and separating the remaining hydrocarbon material from the acid liquor containing the sulphated hydrocarbons.

23. The'process of producing a rened motor fuel product from an unrened distillate containsubjecting the unrened distillate to the action of a reactive acid rening agent containing sulfuric acid, intimately contacting the unrened distillate with said refining agent at a temperature below 40 F. which is sufficiently low to prevent substantial polymerization of the unsaturated hydrocarbons contained in the distillate, separating the refined distillate from the acid renlng agent and thereafter neutralizing the rened distillate.

24. The process of producing a rened motor fuel product from an unrened distillate containing unsaturated hydrocarbons, which comprises subjecting the unrefined distillate to the action of concentrated sulfuric acid, intimately contacting the unrefineddistillate with the concentrated acid at a temperature of from about oil, which comprises passing said distillate in a continuous stream through a series of reaction zones in contact with sulphuric acid, introducing concentrated sulphuric acid into the last zone of the series and passing it through the said zones countercurrent to and in intimate contact with the said distillate, removing the treated distillate from thel last zone of,the series and spent acid liquor from the first zone of the series, maintaining the materials in said zone under a superatmospheric pressure, and maintaining the acid and distillate in said zones at a temperature adapted to prevent substantial polymerization of the olefin constituents contained in said distil- 70 late.

28. The method of forming diaikyl siufates from olefin 'containing'materiaL which comprises intimately contacting olen containing material with concentrated sulfuric acid in a contact zone to form acid alkyl sulfates, passing the acid alkyl sulfates into a second zone in intimate contact with an additional quantity of olefin containing material to convert the acid alkyl sulfates into dialkyl sulfates, and maintaining a relatively low temperature in said contact zones which is sufciently low to prevent substantial polymerization of the olen material.

29. The method of forming dialkyl sulfates from olefin containing material and sulfuric acid, which comprises intimately contacting olen containing material with sulfuric acid in a contact zone to form acid alkyl sulfates, maintaining a sufliciently low temperature in said zone to prevent substantial polymerization'of the olefin material, transferring the acid alkyl sulfates into a second zone of lower temperature and intimately contacting the same with an additional quantity of olefin containing material to convert said acid alkyl sulfates into dialkyl sulfates.

30. The process of refining a cracked gasoline by the treatment thereof with sulfuric acid, which comprises passing a mixture of cracked gasoline and liquefied normally gaseous hydrocarbons in intimate contact with concentrated sulfuric acid in a contact zone, maintaining the gasoline mixture and sulfuric acid at a temperature below 40 F. which is sufficiently low to prevent substantial polymerization of the unsaturated olefin constituents contained in said gasoline, and thereafter separating the treated gasoline from the sulphuric acid.

31. The process of refining a gasoline containing unsaturated hydrocarbon constituents which tend to polymerize upon being treated with concentrated sulfuric acid, which comprises passing the gasoline to be refined through a series of contact zones in intimate contact with concentrated sulfuric acid, conducting the sulfuric acid through the series of zones in a direction countercurrent to that of the gasoline being refined, removing the treated gasoline from the last treating zone of the series and removing the spent acid liquor from the first treating zone of the series, effecting prevent substantial polymerization of the unsaturated constituents contained in the gasoline, and cooling the gasoline following its intimate contact with acid in one zone and prior to its contact with acid in the next succeeding zone of the series.

32. The process of refining cracked gasoline containing polymerizable unsaturated hydrocarbon constituents with cold sulfuric acid, which comprises intimately contacting the gasoline and cold sulfuric acid in a plurality of separate treating zones, separating the gasoline from the acid with which it is brought in contact in each zone and passing the thus separated gasoline at a relatively low temperature to the succeeding contact Zone, and positively cooling the gasoline during its passage through said series of zones to a temperature sufficient to maintain the gasoline below a temperature of 40 F. which is suiiciently low to prevent substantial polymerization of the unsaturated constituents contained in the gasoline.

33. The process of refining cracked gasoline of. cold sulfuric acid land thereafter separated' from said acid, continuously introducing the gasoline to be treated into contact with the acid in each stage, continuously separating gasoline from the acid in each treating stage and conducting the resulting separated gasoline into the next succeeding treating stage, and maintaining the temperature of the gasoline and acid in each treating stage below a. temperature of F. which is suiciently low to prevent substantial polymerization of the unsaturated constituents contained in the gasoline being treated.

34. The process denedby claim 33 in which the gasoline and sulfuric acid brought into intimate contact with each other in each zone are maintained under a substantial superatmospheric pressure.

35. 'Ihe process of refining a doctor sour gasoline containing substantial proportions of unsaturated hydrocarbon constituents, which comprises chilling the gasoline to be treated to a relatively low temperature and passing it into a treating zone in contact with cold sulfuric acid, agitating the gasoline with the acid in said zone to bring the gasoline and acid into intimate contact with each other, separating the gasoline from the resulting acid liquor and passing. the thus treated gasoline into a succeeding treating zone in contact with a body of cold concentrated sulfuric acid, agitating the gasoline with the acid in said succeeding zone to thereby bring the gasoline and acid into intimate contact with each other, separating the treated gasoline from the acid following said contact, neutralizing the thus treated gasoline, and maintaining a temperature in said acid contact zones below a temperature of 60 F. which is sufficiently low to prevent substantial polymerization of the unsaturated hydrocarbon constituents contained in said gasoline.

36. The process of producing a rened motor fuel from an unrei'lned oil containing unsaturated hydrocarbons which are polymerizable with concentrated sulfuric acid at the temperatures employed in the usual sulfuric acid treatment and sulfur compounds which tend to make the unrefined oil sour, which comprises cooling the unrened oil to be treated and concentrated sulfurie acid to a temperature below that at which the resulting cold concentrated sulfuric acid will cause substantial polymerization of the said unsaturated hydrocarbons, thereafter intimately mingling the cooled acid and the cooled unreiined oil to treat and refine the latter at relatively low temperatures whereby substantial polymerization of said unsaturated hydrocarbons is prevented `and the excess sulfur compounds removed from thev oil, and separating the reiined'oil from the acid residue.

37. The process defined by claim 36 in which the cooled oil and concentrated acidl are intimately mingled at a temperature below 40 F. and in which conditions are controlled to prevent a substantial rise in the temperature by the heat evolved from the reaction between the oil and the acid.

38. The process-defined by claim 33 in 'which the conditions of intimate contact between the` gasoline and the cold sulfuric acid are so controlled as to prevent a substantial rise in the temperature in each stage by the heat evolved from the reaction between the gasoline and the acid. Y

ROBERT M. ISHAM. HENRY N. LYONS.

asv

CERTIFICATE oF coRREcTIoN.

` vPatent No. 2,-1)45,O25. 1 'January 219419599v ROBERT H. IsHAR, ET AL. It is hereby certified that error appears inthe printed specification of the above numberedlpatent requiring oorrectionas follows: Page 5, second column, line 66, claim 2T, for the word "zone" read `zones; and that the-'said 'Letters Patent should be read with this correction therein that the same ma.;r conform to'fthe record of theoase inthe Patent Office.'

signed and seals@ this ist day of August, A. D, 1959.

Henry Van .lursdelle (Seal) l Acting Commissioner of `Patents.

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