US2330118A - Hydrocarbon conversion and polymerization - Google Patents

Description

A m o t a 1.1%; /a

Sept. 21, 1943. F. E. FREY 2,330,118

HYDROQARBON CONVERSION AND PQLYMERIZATION Griginal Filed Jan. 27, 1937 2 Sheets-Sheet l Q a l g 53 INVENTOR FREDERICK a-FREY 9 BY p=.21,1943. F. E. FREY" 2,330,118 1 HYDROCARBON CONVERSION AND POLiMERIZATION Original Filed Jan. 27. 19:s7 2 Sheets-Sheet; 2

INVENTOR FREDERICK E. FREY paraffin-olefin union.

1 Patented Sept. 21, 194:3

umzo STATES PATENT OFFlCE' HYDROCARBON CONVERSION AND POLYMERIZATION Frederick E. Frey, Bartlesville, kla., assignor to Phillips Petroleum 0 Delaware Original application Ja ompany, a corporation of 122,658. Divided and ary 3, 1941, Serial No. 373,047

3 Claims. ((31. 196-2) This invention relates to the conversion of low boiling hydrocarbonslnto higher boiling'hydrocarbons, and more particularly to apparatus wherein a mixture of olefinic and saturated-bye 'drocarbons while under pressure and at a reaction temperature in a gaseous or Vaporous state, is subjected in a reaction chamber to conditions of-high turbulence while undergoing reaction to produce in high yield hydrocarbons of higher molecular weight suitable for motor fuel.

This application is a division of my copending application Serial No. 122,658, filed January 2'7,

1937, now U. S. Patent 2,266,019, granted Decemv ber 16, 1941;

It is an object of this invention to provide an apparatus wherein chemical reactions between reactantsin the vapor phase may take place in an enlarged reaction chamber while a high degree of turbulent circulation and mixing is maintained.

Another object of this invention is to provide,

in a simple-form of apparatus, means wherein olefins maybe thereby dispersed in 'parafiins as the ole'fins are consumed by reaction. thereby augmenting the formation or higher parafilns by Another object'of-this invention is to provide an apparatus for the reaction of an olefin-containing hydrocarbon mixture with a minimum formation of higher boiling hydrocarbons beyond the ordinary gasoline boiling range.

A further object of this invention is to provide an apparatus whereby gaseous reactions involving olefin-containing hydrocarbon mixtures are carried out a'diabatically in a reaction chamber, except as the incoming and effluent streams will have a sensible heat content.

Still a further object of my invention is to provide an-apparatus wherein a paraffin-olefin hydrocarbon mixture is subjected in a reaction chamber of enlarged cross-sectional area to re- Volume Per cent CH4 and H1 35. 4 I 22. 9 Ciao. .Q. Y 13. 3 ("1H1 18. 1

cm CAHB 6. 5 CH1 4. 8

nuary 27, 1937, Serial No.

this application Januvapor phase to produce a hydrocarbon fraction boiling in the gasoline range there is produced, in addition to oils heavier than the-originalmaterial, a mixture of normally gaseous hydrocarbons. This mixture may be treated by absorp- TABLE I Gas from high temperature oil cracking Constituent It has beenproposed to subject this material, under an elevated pressure and at a suitable temperature, to reaction in an elongated tube coil,

action conditions'favorable to the juncture of parafiin and'olefin molecules to produce-predominantly non-aromatic polymers in particularly high yield, based on olefin consumed,

Still a further objectoi my invention is to effect thermal conversion of a mixture of simple parailins and oleflns into motor fuel in an enlarged reaction chamber in a new manner whereby an increase in yield-and in conversion per thermal treatment is realized.

Further objects and advantages will become apparent as. the discussion and disclosure proceed.

surrounded by a gaseous fluid of a temperature lower than the reaction temperature. Such a reaction is highly exothermic in nature, and the surrounding fluid, of a lower temperature than the reactants, will remove some of the heat produced by the reaction so that the reaction will not overheat the reaction coil and become uncontrollable.

It has also been proposed to heat a normally gaseous hydrocarbon mixture containing little if any hydrogen and with about 25 per cent by vol me or more of unsaturatedhydrocarbons, and

pass it into a thermally insulated enlarged reaction chamber where reactions take place to form higher molecular, weight hydrocarbons, such reactions involving the olefinic hydrocarbons present. The composition of such a gaseous mixture when heavier petroleum oils are cracked in the 5a i giVEll in- Table II.

TABLE 11 Constituents Volume Per cent reactants and of the products desired, and with an appropriate degree of preheat. Gases produced from petroleum oils by familiar pressure cracking processes are among those suitable for conversion. as these gases contain lower volume percentages of olefin and higher percentages of the higher gaseous parafiins, such as propane and butane, than gases produced by low pressure vapor phase cracking.

Processes have also been disclosed wherein it is proposed to treat artificially compounded hydrocarbon mixtures of olefin concentrations of per cent or less, operating in such a manner that reactions involving union of parafins and olefins are predominant, wherein higher molecular weight paraflflns formed as the result of such-reactions constitute the major products. Such reactions are favored by high pressures and low olefin concentrations, the latter brought about by carefully controlled and proportioned addition of olefins to predominantly paraffinic hydrocarbon streams.

I have disclosed one method of operating these processes in the U. S. Patent 2,002,394, issued to me May 21, 1935, for a Process for converting hydrocarbons. Here the reactions between the olefins and the paraifins are favored and reactions involving olefins only are minimized by the low olefin concentration at any one point.

One of mycopending applications, Serial Number 12,981 filed March 25. 1935, for a Process for converting hydrocarbons, which is now U. S. Patent 2,104,296, discloses reactions between paraffins and olefins, wherein paraffin'ic material is passed through an endless circulatory cy'cle, while maintained at reaction temperature and pressure, and an olefin-containing hydrocarbon mixture is introduced at one part of the cycle,

, troducing small amounts of olefins into a paraffinic stream at a single point, and allowing the reaction to proceed in a continuation of the tube coil or by introducing the mixture under pressure and at a reaction temperature into an enlarged chamber where reaction proceeds.

In thermal and catalytic processes for convert.-

: ing lower molecular weight hydrocarbons to higher molecular weight hydrocarbons, now

7 known to the art, especially where use is made of reaction chambers for reacting hydrocarbon mixtures of substantial olefin content, there is a strong tendency for olefini'c hydrocarbon moleculesto react with other olefinic hydrocarbon molecules, thereby forming progressively higher molecular weight molecules. This is especially true when local concentrations of olei'lnic molecules are high. Such'progressive reactions tend to become quite deleterious in nature, and heavier oils areformed which are out of the gasoline boiling range and which tend to produce tar and coke easily. If a large reaction chamber is used reactions may not take place uniformly throughout .the chamber, resulting in a product which has unnecessarily large amounts of heavier reaction products at the expense of more desirable reaction products boiling in the gasoline range.

Furthermore, if n olefin-paraffin mixture is thermally reacted t a temperature below that at which theparaflin hydrocarbons present are appreciably decomposed so that reactions involving only olefins are predominant, the proportion of normally liquid hydrocarbons then formed is low in processe heretofore known to the art. In such a case the greater part of the paraffin hydrocarbons present will be present essentially jecting the reactants at such a velocity and in such a direction that uniform direct transit through the reaction chamber from inlet to outlet is prevented, but instead a turbulent circulatory'motion is maintained within the chamber while the entering reactants are dispersed intimately in large volumes of the partly reacted hydrocarbons and while a reaction temperature preferably of 700 to 1100 F. is maintained. I have also found that if high pressures are maintained during conversion, namely in excess of 1000 pounds per square inch and preferably of 2000 to 4000 pounds per square inch or more,

I. higher yields of hydrocarbons in the gasoline boiling range are obtained, and the higher the pressure the moreefiicient is the consumption of paraffin hydrocarbons by direct union with olefins. Indeed with proper equipment pressures of 5,000 to 10,000 pounds per square inch or more may be used.

A novel feature of my invention is the use of a reaction chamber which will serve a somewhat different purpose from those previously used in the art of hydrocarbon cracking and polymerization. I Its general design and construction, and the design, construction and position of the inlet and outletconnections will be such that the reactants within it will be put into and maintained in ahigh state of turbulent circulation and mixing. In the familiar cracking of petroleum in an enlarged reaction chamber, such circulation of hydrocarbon material within the chamber is undesirable in'many cases, since it leads to the discharge of uncracked hydrocarbons from the chamber and therefore this is at present minimized in practice. However under the conditions peculiar to my process, as will be discussed,the

' furnish olefin reactants.

v 2,880,118 nature of the reactions taking place is markedly and favorably affected by such turbulence. The intimate mixing, of incoming reactants with partially reacted'and therefore more highlyparamnic hydrocarbon material insures that an appreciable proportion of the reactions taking place in the chamber will involve the juncture of olefins and parafiins to form higher molecular weight paraflins, and progressive reactions which involve only olefinhydrocarbons are limited in extent so that formation of heavy tars and coke is minimized.

Hydrocarbon material suitable for conversion in my process will contain both paraflins and oleflns, both of which enter into reaction. Of the paraflins, propane, butane and pentane are particularly suitable since they readily enter into reaction with unsaturated hydrocarbons. Ethane and methane are less reactive and in many cases it will be desirable to limit the quantity thereof present in the conversion stock. Any of what the most reactive of the olefins. These constitute the chief hydrocarbon components of pependent cn'jthe temperature within the chamber, upon the composition of the conversion stock, and upon the design of the reaction chamher. The principal and most desired reactions will tend to reduce the specific volume of the hydrocarbon mixture and increase its parafiinicity, and the extent of these characteristic properties will need to be taken into consideration also. I prefer to operate my process so that at least half oithe olefins charged to the process undergo a reaction, and the efliuents of the reaction chamber should not contain more than 5 to per cent by volume of unreacted olefin molecules. To fulfill these conditions the average reaction time should be at least seconds and should not be more than 30 minutes, and I have found that the best results are generally obtained the simple unsaturates, namely ethylene, protroleum conversion still gases, natural gases contain the parafhns named, and such gases will also furnish suitable conversion stock. Suitable concentrating operations to provide a mixture of low methane and ethane content is ordinarily desirable because of the low reactivity of these hydrocarbons. Pyrolysis and dehydrogenation may be applied to saturated hydrocarbons to produced by the so-called vapor phase petroleum cracking are not directly very suitable for the process, although the content of the highly de-- sirable ethylene is high, because the'amount of para'illns other than methane and ethane is too paramns and olefins, usually of suitable composition but with theparaifins in marked predominance. A mixture of methane-low concentrates of vapor phase and pressure cracking gases is accordingly highly suitable because it contains olefins rich in ethylene associated with the desired paraifins.

The paraiiin content of conversion stock for my process should preferably consist mainly of paraflins higher than ethane accompanied by unsaturates constituting from l0 to per cent by volume, or somewhat more, of the total conversion stock. The conversion stock may also contain unconverted hydrocarbons separated from the eiiiuents of the process which are usuallydepleted in olefin. Thus sucha predominantly paraflinic recycle stream consisting mainly of unreacted propane and butane, may be mingled with a charge-stock of high olefin content to form a very desirable conversion stock.

-I use reaction temperatures of 700 to 1100" F., a temperature range wherein olefin hydrocarbons are known to polymerize with themselves under pressure, but wherein paraflin hydrocarbons de-.

' The gases ordinarily with a reaction period of 1.5 to 7.5 minutes. Exact temperatures and reaction periods for any particular case may be readily determined by trial.

In the practice of my process the use of pressures above those heretofore employed, in simple thermal polymerization of olefin-containing hydrocarbon gases in a reaction chamber, decreases formation cf heavy hydrocarbons unsuitable for motor fuel, and with increase in conversion pressure within my disclosed range, the

formation of these undesirable heavy products is.

increasingly suppressed. This'is a contrast to the usual result when the active turbulent circulation and dispersal of reactants is not employed, such procedures usually leading to increased formation of heavy products with increase in pressure, which also is the usual effect of pressure increase when petroleum oils are cracked.

I prefer to practice my process in such a manner that reaction takes place in the reaction chamber without substantial addition of heat or abstraction of heat from the chamber. the reaction is exothermic the reactants may be heated only to such a degree as will sustain reacatures.

tion in the chamber at the desired temperature levels. Thus the temperature of the hydrocarbons entering the chamber may be as much as 150 F. or more lower than the temperature of reaction within the chamber, high olefin contents permitting relatively low preheat temper- This is of advantage in preventing reaction prior to dispersal in the chamber, since the less desired olefin polymerization tends to set in at lower temperature than the paraffin-consuming reactions in the chamber.

Under the conditions of-turbulent circulation and mixing disclosed herein, and treating hydrocarbon gases .of the compositions discussed, I have been able to obtain ultimate yields of higher boiling material in the gasoline range of about 1.25 to 2.5 or more times as large by weight as I' have at other times obtained under similar temperature and pressure conditions, but using reaction zones such that reactions involving only olefins took place. Furthermore, the products of my present process'areconsiderably more parafproduce higher molecular weight hydrocarbons,

" generally paraflini'c in nature.

In the practice of my invention the average reaction time orperiod of residence of the reactants within the reaction chamber will be deflnic in nature. This feature adds greatly to their desirability asmotor fuels, as they'have very goodanti'detonating qualities which can'be considerably .improved with only small addi-.

tions of tetraethyl lead or other detonation inhibitors, and they are not particularly subject to gum formation'and are quite stable during prolonged storage.

a My invention will be more clearly understood by reference to the accompanying drawings, which form a part of this specification, and wherein, 7

Since,

' fied type of reaction chamber,

Fig. '7 is a side view, being broken away in part, illustrating still another type of reaction chamber,

Fig. 8 is a side view, being broken away in part, illustrating a further type of reaction chamer; and

Fig. 9 is a cross-sectional View of the reaction chamber illustrated in Fig. 8, and is takenpn line 99 thereof looking in the direction of the arrows.

Referring now to Fig. 1, one mode of practicing my invention is as follows:

Hydrocarbon material of suitable composition of the type described, is introduced through pipe I, compressed to any desired pressure in excess of 1000 pounds per. square inch by pump II, and passed through conduit l2 to the heating coil I3, which may be housed in any suitable furnace M, or which may be heated by other means. In passing through the coil I 3 the hydrocarbon mixture, or stream, is rapidly heated to a more or less elevated temperature, usually less than 1l00 F., suiiicient to sustain reaction in the reaction I chamber to which it passes. It is desirable that this heating take place rapidly, so that no appreciable or extensive reactions will take place in the coil l3.

From coil l3 the stream is passed through conduit l5 directly to a reaction chamber such as will be described hereinafter and which is designated here by the numeral l6, and which is so constructed that a high degree of turbulent circulation and mixing may be maintained therein,

and the stream is introduced into chamber I 6 in such a manner as to create and maintain this turbulent state, as will also'be discussed hereinafter. Eiiluents from the reaction chamber I 6 are passed through conduit l1 and expansion and control valve l8 to separator I 9. Separator I9 will preferably be operated at a pressur of about 200 pounds per square inch or more, but appreciably less than the pressure maintained in reaction chamber l6. Heavier products of the reactions will pass through conduit 2!) to separating means 2|, wherein heavier oils and tar are separated and discharged through conduit 22 and valve 23. A fraction containing the gasoline boil-. ing rangehydrocarbons produced is passed out of the process through conduit 24 and valve 25, and may be subjected to further treatment with stabilization of the gasoline.

Eiiluents from the chamber 16 not passing a through conduit 20 will consist ofunreacted material and lighter material. These are passed out of the separator I9 by means of conduit 25 to separator '21, wherein a separation is made between unreacted material and lighter material. Lighter material is discharged through conduit 29 and valve 28. Uhreacted hydrocarbons are discharged from the separator 21 through line 30, and may be discharged from the system through valve 3|. Any part or portion or all of this material may --be passed through conduit 32 and valve 33 and into pipe II] where it is mixed with the incoming hydrocarbons and subjected to further treatment.

It is to be understood that the reaction cham- 'bers and all modification thereof herein described are constructed to withstand relatively high pressures and temperatures, and therefore suitably constructed and fabricated from metal.

With reference now to Figures 2 and 3 wherein are illustrated one form of reaction chamber which may be used in practicing this invention, it is to be noted that'Fig. 2 is a plan view of the same, while Fig. 3 is a side view thereof. Such a reaction chamber is of the general configuration of a hollow oblate spheroid, designated by the reference numeral 40, and having the major axis A evidenced in Fig. 2, and the minor axis B as evidenced in Fig. 3. The ratio of A to B may conveniently bebetween the limits of 5:1 and 1:1, and is preferably about 2:1. The reaction chamber 40 here under consideration may be provided with an inlet conduit 4|, through which the efiiuents from the heating coils, such as the onesdescribed in Fig. 1 enter the interior of the reaction chamber. The axis of the inlet conduit 4| is preferably 'on a line with the extension of a chord of the largest possiblecircular cross section of the spheroid constituting the reaction chamber 40. This allows the heated reactants entering chamber 40 by way of conduit 4! to enter therein in such a manner as to set up the desired turbulence andtcirculation within the chamber.

Reaction chamber 40 is provided with an outlet conduit 42, the axis of which is preferably coincident with the minor axis B of the chamber, and on a line with the center of rotation of the spheroidal reaction chamber. The end of the outlet conduit 42 disposed Within the reaction chamber 40 may be provided with apertures at the end thereof as shown at 43, and also provided with an aperture at the top thereof as at 44. The end of the outlet conduit 42 may be closed, if desired, and the contents of the chamber will then pass therefrom through the apertures 43 and 44 above described.

Other types of reaction chambers may be used which will also insure the introduction of the effiuents from the heating coils into the chamber in such a manner that the effluents therein undergo turbulence and circulation. For instance a modified type of reaction chamber is illustrated in Figs. 4 and 5, the body of which comprises av prolate spheroid generally designated by the reference numeral 50, having an inlet conduit SI and an outlet conduit 52, the inlet conduit being positioned with respect to the chamber in relatively the manner as the inlet conduit of the reaction chamber 40. The portion of the outlet conduit 52 positioned within the reaction chamber is provided with'the aperture 53 and 54 as shown.

Fig. 5 is a transverse cross-sectional view of the chamber illustrated in Fig. 4, and is taken on line 5-5 thereof looking in the direction of the arrows, and shows the inlet and outlet co'nduits' 5| and 52 respectively, and their position with respect to the chamber 50.

Still another modification of a reaction chem I ber suitable for use in practicing this invention is illustrated in Fig. 6. Here the reaction chamber generally designated by thereference nupart of the contents of the chamber. Many forms I meral '60, comprises a pair of parallelly disposed conduits GI and '62, which are joined at either end by the curved conduits 63 and 64. To the ends of either of the curved conduits may be fitted the inlet and outlet conduits. As illustrated the inlet conduit 65 is fitted at or near one end, of the conduit 53 and so disposed as to be substantially parallel with conduit 6|, while theoutlet conduit 66 is fitted at or near another end of the curved conduit 63 and is positioned of reaction chambers will meet this requirement,

- including a simple cylindrical form of large crosssubstantially parallel with respect to conduit 62.

The diameter of the reaction chamber 60, beine the same as the diameter or the respective conduits SI, 62, 63 and 66 is preferably about eight (8) or more times larger than the diameter of the inlet conduit '65, and more preferably up to twenty (20) or thirty (30) times larger, or more.

It should be apparent that such a reaction chamber as the one designated by the reference numeral 60, and illustrated in Fig. 6, will serve to set up turbulence in the eilluents from the heating coil when the same eilluents are introduced into the reaction chamber by way of the inlet conduit 65, for the same will be caused to type" M shown in Fig. 71 An outlet conduit is provided In Figs. 8 and 9 there is illustrated a still further modification of a reaction chamber, which is based on the modified type illustrated in Fig. 7, but which is provided with several inlet conduits. The reaction chamber is generally designated by the reference numeralBll, and essentially comprises a cylindrical portion 81 provided with the end portions 82 and 83. Inlet conduits 8 and 85 are provided as illustrated, and are disposed at an angle, but not necessarily the same, with respect to the transverse axis of the cylindrical portion 85 of the reaction chamber 80. It is preferable that the axis of one of the inlet conduits form, a plane with the axis of the'outlet conduit, and that at least one of the other inlets, or the other inlet, have an axis which is not in this plane and which does not intersect either of the aforementioned axes. Where a plurality of inlets are used, the combined cross-sectional area of each'may be such that the linear velocity of the incoming jet of reactants, or eiiluents,-irom each inlet will be the same as if only one inlet conduit .Was normally used. That is, the crosssectional area the length being preferably less than 5 times the diameter. The injection of reactants into the chamber must take place-at a linear velocity sufliciently high to circulate the contents within the chamber at least 3 and preferably 10 or more times on the average past the point of injection, the more vigorous circulation being required with conversion stocks of high olefin content. For a reaction chamber of given,

size it is possible by hydrodynamic calculation to determine the inlet velocity required and the extent to which the cross-section of the inlet orifice must be restricted to obtain the desired degree of turbulent circulatory motion. The inlet orifice may be merely a prolongation of the heating coil of suitably restricted cross-sectional area. The dispersal of the incoming reactants into the circulating contents of the chamber should be sufiiciently rapid and complete to minimize premature polymerization of concentrated and undispersed olefins as theyemerge from the Y inlet into the chamber. Athigh inlet velocities dispersal is more eificient than at lower ones, although the lower velocities may be adequate for sustaining circulation. Dispersal may be assisted by bailies or equivalent scattering devices ,upon which the stream impinges, or a Venturi throat or a series. or Venturi throats of increasing diameter, the smaller discharging into thelarger,

surrounding the incoming stream, the use of multiple jets, and other expedients which will be svious for such use. a

The turbulent circulation and mixing within the reaction chamber of my process, designated by the numeral 16 in Fig. 1, is different from the turbulence which exists in the conduit Hi immediately prior to its discharge into the cham-' ber. The linear velocity of the hydrocarbon material beingheated in the tube coil 13 will generally vary from 20 to 40 feet per second when sectional area of any one inlet conduit will be in circulation of the efiluents of the heating zone entering the chamber resulting in a more uniform reaction. i The relative dimensions or the reaction chambers are such that conversion stock injected at high velocity thereinto will maintain in circulatory motion and in a turbulent state the greater this heating section is designed along conventional lines, and this is in the range of turbulent flow within the tube coilunder the conditions which exist. The restricted cross-sectional area of the coil and the linear velocity of flow through it permits of local mixing only.

insures a difierent efiect, namely a rapid and thorough mixing of. heated and activated reactants with other and partially reacted hydrocarbon material=which is turbulently circulating within the chamber. This circulating hydrocarbon material is in violent agitation, so that extensive over-reacting of localized portions does .not take place, and adequate opportunity is given for olefins to react with parafiins while thinly dispersed in their presence.

desirable. Still higher velocities are usually preferable, and to obtain them the heating coil l3 and the inlet conduit l5 may be of smaller cross section than is usual in gas conversion heating coils, or the end of the conduit 55, discharging I Introducing such a stream into reaction chambers as disclosed into the reaction chamber, may be of restricted cross section, without prohibitive friction losses, so that the jet of reactants entering the chamber will have a velocity of 50 to 200 feet per second or more, and I may use such velocities in my process. A pressure drop equivalent to the velocity' imparted will be experienced at such a constriction. Such discussion as given here is understood,to pertain to any particular reaction chamber which may be used in this process.

-In general, in this process it is desirable to maintain, (1) the reactants and products in circulatory motion in a large portion of the reaction zone, (2) efficient dispersal of olefin-bearing conversion stockentering the reaction chamber, (3) a minimum of stagnant space, other than in proximity to the outlet and in transit to said outlet, (4) and a characteristic flow which minimizes the residence of hydrocarbons for periods much exceeding the average time' of residence in the reaction zone. The familiar principles of hydrodynamics can be app ied in many obvious ways to achieve theconditions of reaction which have been stipulated.

EXAMPLE I As an example of the successful operation of this invention, a hydrocarbon mixture containing 7.8 per cent by weight of ethylene and92.2 per cent of isobutane was rapidly heated to a temperature of about 915 F. and injected from a small orifice at a velocity of about 40 feet per second into a cylindrical reaction chamber having a length about four times the diameter in such a manner that extensive circulation and turbulent mixing took place. The chamber was insulated so as to be practically without any heat loss, and the temperature of the eiiluents was about 940 F., the rise in temperature being due to the exothermic reactions taking place. The average period of reaction within the chamber was about 4 minutes, and the pressure was maintained at 4500 pounds per square inch. The efilug The addition of one cc. of lead tetraethyl per gallon increased this octane rating about ten units, an increase which is unusually high for a motor fuel with such ahigh initial octane number, and especially fora motor fuel produced by thermal conversion of an olefin-containing normally gaseo us hydrocarbon-mixture.

ExAMrLE 11 As an example of the operation of this in- -vention at considerably less pressure, a hydrocarbon mixturev containing 9.8 per cent by weight of ethylene and 90.2 per cent by weight of isobutanewas converted according to the process of Example I, except that the reaction pressure was only 2500 pounds per square inch, the temperature of the eflluents of the chamber was 968.

EXAMPLE III In order to bring out more completely the advantages of this invention, a third example is. presented for contrast. A hydrocarbon mixture containing 16.5 per cent by weight of ethylone and 83.5 per cent of isobutane'was rapidly heated to a reaction temperature of 941 F. under a pressure of 4700 pounds per square inch and allowed to react in an extension of the heating coil for a period of 5.1 minutes, wherein no turbulent mixing into recirculating hydrocarbon could take place. 20.4 per cent by weight of gasoline, of a composition shown in Table III, run C. It is to be noted that the normally'liquid products of this run are not predominant in hexanes, that a large amount of heavier liquids were formed, and that a large amount of unsaturated hydrocarbons are present. The liquids corresponding to octane and higher were rich in aromatics.

TABLE III Gasoline from normally gaseous hydrocarbons Run number sage: A. 'O 0 Parafllnio products octanes and lighter 7 These .three examples have all shown the thermal treatment of a normally gaseous hydrocarbon mixture composed of ethylene and isobutane. The invention is not to be considered to-be limited to the use of such a mixture, as these hydro- F., and the time of reaction was 4.3 minutes. The

pertinent data of this run are given in Table- III, run B. The hexane fraction had practically carbons have no special properties or characteristics which would tend to make them specifically different from any of their analogues, nor should any restriction be made to such a low olefin content. These conditions were chosen only because the product of their interreaction would be easily identified in the eilluents, and the results of different experiments would bring out the diiferences due to diflerent conditions of operation, without being obscured by results of other variables. Any olefin containing normally gaseous hydrocarbon mixture, containing up to 50 per cent by volume of olefins when treated under conditions most suitable for that particular mixture will react in an analogous manher.

A consideration of the analyses of the normally The efliuents' contained 2,aso,11s

liquid products of these three examples brings out three very important and pertinent points.

1. The hexanes produced in run A were 46.0

per cent by weight of the products, in run B they were 39.9 per cent, while in run they were only 17.5 per cent. This illustrates forcibly the increased extent of reactions between olefins and parafllns which result from practicing my in-- vention.

2. A consideration of the weight per cent of normally liquid hydrocarbons produced per pass in comparison with the olefin content of the charge stock-is very interesting. Although the charge in run C contained 16.4 per cent of olefin which reacted, 2.65 times as muchas the charge to run A, only 1.24 pounds of liquid products per pound of olefin resulted in run 0 while 1.45

pounds of liquid products resulted in run A, an I increase of 17 per cent in run A. v

3. Both runs A and B produced liquid products containing about '73 per cent by weight of saturated hydrocarbons of eight or fewer carbon atoms per molecule, while the products from run C contained only about 64 per cent of equivalent material, as well as a considerably larger proportion of heavier liquids and tar. This again is a direct and valuable result of using my invention, which is not demonstrated or hinted at by the workers in the prior art.

' 'As previously discussed herein, I have found that when olefin molecules react with paraifin molecules to form higher molecular weight parafiins, the reactions are greatly influenced by the total pressure on the system, among other variables. If the total pressure is high, a lower temperature may be used and the parafiinicity of the normally liquid products-is considerably increased, and as a concomitant result the ultimate drocarbons in the products of my process, and have advanced this discussion only as a possible explanation, and I do not wish to give the impressionthat I am attempting to claim herein any new and novel theories or mechanisms. of reaction, however such theories should not be so construed as to limit the scope of this invention as set forth.

Although preferred apparatus and methods of operation have been discussed, it is to be understood that my invention is not limited by such discussions or the examples given, but only by the claims hereto appended.

I claim: a 1. Apparatus for sure and temperatureto convert the same into liquid hydrocarbons, the same comprising a hollow substantially spheroidal reaction chamber having an inlet conduit and an outlet conduit disposed in different planes, means for injecting reactants through said inlet conduit at high velocity, said inlet being so disposed with respect to the interior of said chamber as to cause reactants to be injected therethrough in such a direction as to turbulently mix with circulating contents of said reaction chamber, and said outlet beingpositioned substantially at a point of limited circulation in said chamber.

2. A reaction apparatus for the treatment of low boiling saturated and unsaturated hydrocarbons to form higher boiling predominantly saturated hydrocarbons, which comprises a hollow spheroidal reaction chamber having a yield of higher molecular weight material within the motor fuel range is also increased, based on a unit weight of charge stock and any given reaction, the yield is increased by an amount corresponding more or less to the amount of paraffinic material entering into the reaction. Since, however, the mode of operation also exerts a considerable influence on the products, a more parafiinic material may be produced by practicing my invention at lower pressures than by a less-favorable mode at higher pressures, despite the less favorable condition of lower pressure for efilcient participation of parafllns;

In the examples given, run B at 2500 pounds per square inch produced much more parafiinic material in the desirable gasoline boiling range than was produced in run C, although the latter was carried out at a much higher pressure and a somewhat lower temperature. Thus by practicing myinvention at 2500 pounds per square inch pressure, very desirable and beneficial results are produced over conventional once-through processes at equal or even higher pressures.

. Considerable discussion. has been presented herein concerning the theory of the molecular ratio of major axis to minor axis between about 5:1 and 1:1, an outlet conduit of small cross sectional area and substantially on a line with a minor axis of said reaction chamber, and means comprising an inlet conduit of small cross sectional area substantially on a line with a chord, other than-a-diamemr, of the largest possible cross section'of said chamber taken in a plane substantially perpendicular to said outlet conduit to inject reactants into said chamber in such a manner as to establish and maintain in said chamber a high degree of circulation to effect a rapid mixing and dilution of the incoming charge and the circulating reacting mixture.

3. A reaction apparatus for the treatment of low boiling saturated and unsaturated hydrocarbons to form higher boiling predominantly saturated hydrocarbons, which comprises a hollow reaction chamber having the shape of an oblate spheroid with the ratio of the major axis to minor axis between about 5:1 and 1:1, means comprising an inlet conduitof small cross sectional area on a line with a chord, other than a diameter, of the largest possible circular cross section of said oblate spheroid to inject reactants in a direction and manner such as to establish and maintain a high degree of circulation and mixing of the chamber contents to effect a rapid mixing and dilution of the incoming charge and the circulating reaction mixture, and an outlet conduit of small cross sectional area substantially on a line with a minor axis of the largest possible elliptical cross section of said oblate spheroid and substantially perpendicular to said inlet conduit.

- FREDERICK E. FREY.

the treatment therein of nor- 'mally gaseous hydrocarbons under elevated prescERTIFicATE'oF CORREQTION. Patent No. 2,550,118; 1 September 21, 1915,

FREDERICK E. 'FREY.

It is hereby certified that 'erroriappears in the printed specification of the above numbered 'p'atentrequiring correction as follows: Page 6, sec- 0nd column, line 14.2, Table 'III, column- Cv thereof, for "LL05" read --1.?J4.--; and that the said Letters 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 seeled this 50th day of November, A. D, 1911.5

Henry Van Arsdale, acting Commissioner of ratents.

(Seal)

Images