Патент USA US2408727код для вставки
2,408,725 Patented Oct. 8, 1946 UNITED STATES PATENT oEElcE , 2,408,725 HYDROCARBON CONVERSION Arnold Belchetz, Kew Gardens, N. Y., assignor to pany, Jersey City, N. J., The M. W. Kellogg Com a corporation of Delaware Application September 4, 1942, Serial No. 457,530 15 Claims.A (Cl. 2604683.15) 1 This invention relates to an improved method for producing olefin polymers. More particularly, the invention -relates to an improvement in the method in which olefins are ñrst absorbed in a liquid acid polymerizing catalyst, and the extract is then heated to polymerize the absorbed olefms. Olefm hydrocanbons may be absorbed at rela tively low temperatures in a liquid acid polymer iZirlg catalyst such as sulfuric acid or hydro-fluoric acid, and the absorbed olefìns may then be poly merized by heating the extract to a suitable poly merizing temperature. The conditions under which olefin hydrocarbons are absorbed by the liquid acid pclymerizing cata understood, however, that the invention is not limited to the use of this specific catalytic agent but includes the use of other liquid acid catalysts, such as hydrofluoric acid, which are capable of absorbing olefin hydrocarbons at temperatures below polymerizing temperatures and promoting polymerization of the absorbed olefins when the extract is heated to a suitable temperature, In the selective »absorption of isobutylene in sulfuric acid a mixture of gases containing iso butylene, normal butenes and any accompanying parañin hydrocarbons is contacted with the sul furie acid under conditions eiiective to produce the desired absorption of isobutylene by the acid. These conditions are selected, with respect to the lyst depend upon the molecular weight of the 15 use to which the polymers and the remaining normal butenes lare to be put, to produce a greater olefin hydrocarbon and also upon the molecular or lesser degree of absorption of normal butylenes structure thereof. For example, in the absorp along with the isobutylene. When the principal tion or" butylenes in sulfuric acid it is found that kpurpose of the process is to obtain di-isobutylene isobutylene is absorbed to a substantial degree at temperatures which are too 10W to effect substan 20 for hydrogenaticn to iso-,octane a greater degree of absorption of normal butylenes is tolerable tial absorption of the normal butylenes. The than in an operation carried out for the primary selectivity of the absorption of isobutylene is ef purpose of producing normal butylenes, substan-_ iected also by the strength of the acid, the ratio tially free oi isobutylene, as a source material for of acid to butylenes and the time of contact. the production of butadiene. In operating the The selective absorption of isobutylene from a process as a preliminary step for the production mixture including normal butylenes is theL of butadiene it is desirable to effect as complete acid”V process which has been used extensively for as practicable a removal of isobutylene from the the manufacture of tertiary butyl alcohol or in mixture by absorption while keeping the a= sorp the preparation of di-isobutylene for hydrogena tion of normal butylenes at a practical minimum. tion to iso-octane. The isobutylene-acid extract is separated from ` » The invention will be described further by speciiic reference to a modification of the “cold the unabsorbed hydrocarbons, and the latter are . then transferred elsewhere for further use, such acid” process, although it will be readily under as in the production of butadiene. The extract stood that the invention is not limited to such is then treated to regenerate the acid. This may specific application -but includes within its scope hydrocarbon by be done by heating the extract to a temperature , the polymerization of any oleñn suiiìciently high to polymerize the absorbed ole successive absorption of the olefin hydrocarbon in ñns or .by diluting the extract to a lower acid the liquid acid catalyst and polymerization of the strength and heating the dilute extract to evolve absorbed olefin by heating the extract. The “cold acid” polymerization of isobutylene is selected as 40 the isobutylene or by diluting the extract to a still lower acid strength and heating the dilute the speciiic example of the application of the in extract to evolve tertiary butyl alcohol. In the vention for the reason that it is an important methods involving dilution the acid necessarily step in the production of isooctane and is a valu able method for separating isobutylene from nor must be reconcentrated for further use in the -mal butylenes prior to subjecting the latter to 45 absorption step. Preferably, therefore, the ex ’for the production of butadiene. tract is treated Without dilution to polymerize the , dehydrogenation oleñns and regenerate the acid at the strength It will be understood, however, that the invention required for the absorption step. Relatively con is applicable also to the polymerization of olefins having a greater or less number of carbon, atoms having a strength between centrated sulfuric acid than isobutylene and is applicable 50 63 and 67 per cent is preferred for selective ab sorption of isobutylene. At lower concentrations also to the polymerization of oleñn hydrocarbons other than iso-oleiins such as normal olefins and ' the rate of absorption decreases, and the rate oi corrosion of steel equipment increases. At higher dioleiins. For example, the process is applicable t0 the polymerization of normal butenes or buta 55 acid strengths the rate of absorption of normal dienes although these applications of the inven butylenes increases. The polymerization of the isobutylene absorbed tion are at present less important than the poly in the extract presents serious diiñculties in com merization of isobutylene. ~ mercial operations because the corrosive eiîect of In the further description of the Ainvention ref erence will be made to the use of sulfuric acid as 60 the acid is greatly intensified when the extract the liquid acid polymerizing catalyst. Itis to be 2,408,7'25 Ii is heated to the temperatures necessary to effect polymerization of the absorbed isobutylene. Previous practice in the commercial “cold acid” polymerization of _isobutylene involves heating the extract by passage thereof through exter those having three, four or five carbon atoms per moleculeare preferred because ci the relation ship of their boiling characteristics to the boil ing characteristics of the isobutylene and be cause they are readily separable from the re nally heated coils consisting of copper or steel sulting polymers by fractionation. While the or lead. Heating coils made of steel or copper use of lower boiling or higher boiling materials have a relatively short life due to the corrosive is Within the scope of the invention, these are effect of the extract and require frequent re placement. -By using thick. Walled lead coils a 10 practical ordinarily for use in the polymeriza tion of isobutylene only Iwhen the sensible heat somewhat longer useful life is attained, but the‘s of the heating iiuid is sufficient te heat the ex also require replacement at a frequency-which, in vievv of the expense of the tubes, is undesirable. In accordance with the present invention the isobutylene-acid extract is heated to the poly plication of an excessively high pressure to main merizing temperature, without contact at the extract with the above-mentioned metal coil-s at Whereas higher boiling materials require heating tract to the polymerizing temperature. Rela tively low-boiling heating ñuids require the ap tain liquid phase conditions in the reaction zone, the polymerizing temperature, by contacting the the heating iluid to an excessively high tempera» extract with a hot fluid whereby the extract is heated to a temperature sufficiently high to poly ture to vaporize it at the pressure necessary in the reaction zone. In the selection of a heating fluid those ma" terials should be avoided which will produce un merize the absorbed isobutylene. Preferably, heating of the extract is effected by cont-acting the extract with a vaporized fluid which is con densed by contact with the extract, the sensible heat and heat of vaporization of the huid being suilicient to impart to the resulting mixture a temperature sufficiently high to polymerize the isobutylene. Preferably also polymerization of the isobutylene is eflected by contacting the ex desirable ‘by-products either by reaction with themselves or'with the isobutylene polymers or which react with the acid catalyst to deactivate it. Low-boiling saturated paraiiin hydrocarbons suoli as propane, the butanes and pentaries are tract with a vaporized fluid which is similar in advantageous heating fluids because of their rel ative inertness `in the reaction zone. However, the use of other low-boiling hydrocarbons which boiling characteristics to isobutylene. For ex ample, the polymerization of the absorbed iso For example, vaporized propylene, butylene-p,I and butylene is effected advantageously 'by mixing the extract with vaporized butane, either iso butane or normal butane, the temperature of the butane and the proportions of the butane and extract being regulated to produce a liquid mix ture of the but-ane and extract at the desired polymerizin'g temperature. The use of normal butane or isobutane is es are more reactive is not necessarily precluded. pentenes may lbe usedto supply the necessary heat to the mixture as they undergo polymeriza tion in the reaction zone increase the yield of olefin polymers and amplify the supply of heat by the release of heat of their reaction. Iso butylene obviously is satisfactory since it forms a product indistinguishable from that formed by polymerizing the absorbed isobutylene. Normal pecially advantageous because oi’ the relation 40 butylenes and propylene are satisfactory if the products of their polymerization can be tolerat ship of the boiling points of these materials to ed in the polymer product of the process. the’boiling point of isobutylene. Since it is pref When the process of this invention is employed erable to effect polymerization of the isobutylene while maintaining the extract in a liquid con 45 to separate isobutylene from the fresh feed to a process for making butadiene the succeeding dition, it is desirab e rto maintain the polymer stages of the latter process may furnisii a hy ization reaction zone at a pressure suñ‘iciently high to prevent vaporization of isobutylene. the drocarbon heatingmixture fluid. After Iwhichthe is treatment suitable for of use a gas When using normal butane vas the heating iiuid the> pressure which‘is maintained on the reac 50 ecus hydrocarbon mixture, consisting essentially of C4 hydrocarbons-and including iso-olei'ins and tion zone to prevent vaporizaticn oi isobutylene normal oleñns, in accordance with this process, is sufficient to insure condensation of the vapor`to effect substantial removal of iso-oleñns the re ized normal butano lwhen it is mixed with the maining unabsorbed hydrocarbon mixture or extract. When using vaporized-i-sobutane as the dinarily is then subjected to a further extraction heating íluid it is necessary only lto apply a slightly higher pressure on the reaction’z-one to 55 treatment, for example with acetone, to separate oleñns from paraflins. The unabsorbed parai insure condensation of the isobutane and the fins from such a treatment ordinarily consist of release of the heat of vaporization thereof. a mixture of butanes proportions of isobutane Normal butano and isobutane Vare preferred and norm-al butane which depend upon the char agents as heating ñui'ds for polymerizing iso butylene because oi their relative inertness in the 60 acter of the process in which the gas mixture is formed. If the original feed is obtained by a reaction and because of their relationship to the thermal cracking treatment of hydro-carbon oils Iboiling characteristics of the isobutylene. It is the butano mixture is found to predominate in evident, howeverythat if the sensible heat of the normal butane, whereas ir" a catalytic hydrocar heating fluid is sufficient alone to produce the desired polymerizing temperature, any gas or va 65 bon oil cracking process is the source of the gas mixture the butane,; predominate in isobutane. por may be used which does not condense on be ing mixed with the extract, or any unvaporized liquid may be employed. It is evident, also, that for the polymerization of oleiîn hydrocarbons other than isobutylene by means of a condensible heating tanes having fluid different other heating boiling fluids characteristics than the may be employed. Ordinarily, low-boiling hydrocarbons vsuch as In either case this mixture constitutes a useful heating fluid for use in the present process. Ordinarily, the mixture of normal butano and isobutane remaining after the extraction of ole ñns contains a trace of isobut'ylene and a few per cent of normal butylenes. The presence of these oleñns in the heating fluid is not objectionable, however, since they are polymerized along with thefisobutylene absorbed inthe acid polymerizing 2,408,725> nozzle >2 by means of line 8 which connects ac cumulator -I with mixing nozzle 2. Line 8 is pro vided with a pump 9 for introducingthe'heating fluid" into mixing nozzle 2 against the reaction pressure. Heating meansv I0 is provided in line 8 to heat the heating fluid to the desired tem perature. Preferably, the heating fluid is heated catalyst. The presence of the polymers of such olefins in the polymer product is unobjectionable if the polymer product is to be supplied as fresh feed _to an alkylation process. If the polymeris to be hydrogenated to iso-octane the presence of a small proportion of normal butenes in the heat ing fluid is not objectionable for the reason that the high proportion of isobutylene in the reac tion zone will result in cross polymerization yof’ the normal butylene with isobutylene, resulting inthe production of an. iso-octene which can be hydrogenated to an octane of high octane ,num at I0 yto a temperature sufficiently high to vapor ize it under the pressure maintained in line 8 and reactor I. - 'As stated above, preferred heating fluids for the polymerization of isobutylene in accordance with the present invention are isobutane and ber.- Theuse of a gas mixture from this sourceas the heating fluid in this process is particularly advantageous if 'the gases are obtained originally normal butano. The use of normal butane per mits the maintenance of a- slightly lower pressure in reactor I but, on the other hand, the use of fromga catalytic cracking process and if the poly isobutane requires only a slightly higher pres mer product is to be employed as fresh feed to an alkylation process since, as pointed out above, sure and does not require heating to as high a temperature at I0 to vaporize it. Furthermore, if it is desired to employ the isobutylene polymer such a mixture predominates in isobutane. While inthe above discussion of suitable heat 20 product as charging stock to an alkylation op ing fluids specific reference is made only to hy eration for the production of iso-octane, the use of isobutane as the heating fluid is advantageous drocarbons, it is to be understood that the inven tion is not limited to the use of hydrocarbons as since 'its presence in the polymer product does heating iiuids. Any suitable ñuid may be used not require fractionation prior to charging the which does not form undesired reaction products. polymer to» the alkyation process. In this Consequently, fluids other than hydrocarbons specific example, therefore, isobutane is accumu which meet this necessary requirement may be lated at 1 and charged into mixing nozzle 2 at the used, particularly those which may be mixed desired rate after having been vaporized at I0. The amount of isobutane required for poly with the olefin-acid extract in a vaporized con merizing each unit of isobutylene charged to the dition and which are condensed by contact» with the extract at the reaction temperature and pres system in the` extract through line 3 increases sure. For examples of suitable »heating fluids as the concentration> of isobutylene in the ex other than hydrocarbons reference lmay be made tract decreases. The molar ratio of HzSO‘i to to the ethers, such as dimethyl ether and diethyl` (74H3 inthe extract may vary from 0.5:1'.0 to ether, alkyl chlorides such as methyl chloride 4.0:l.0. It is preferable when extracting iso and ethyl chloride. The ethers are preferable butylene in preparation for the polymerization because of their relative inertness under the poly step to maintain the concentration of isobutylene in the extract supplied through line 3 such that merization reaction conditions. nection with the specific application thereof to molar ratio of H2SO'4 to Cil-Is is within the 40 Ythe range of 0.7:1 to 1.2:1.0. Higher molar ratio-s of the polymerization Vof isobutyene. Inconnection acid to isobutylene increase the heat requirement The invention will be described further in con with such further description reference will be made to the accompanying drawing which illus trates diagrammatically an assemblage of appa ratus for carrying out the specific application of the invention to the polymerization of iso butylene. It is to be understood, however, that the invention is not limited by such specific refer ence to the polymerization of isobutylene or by the reference to a specific assemblage of appa 50 ratus 'since the 'principles of operation illustrated of the polymerization step substantially and lower the selectivity of the extraction operation. It is preferred ordinarily to maintain the poly merization zone at a temperature Within the range of 150° .to 230° F. Lower temperatures may result in incomplete regeneration of the acid. The use , of higher temperatures involves the danger of de composing the acid. Within the range of tem peratures given above the preferred range is 170° F. to 210° F. Within this preferred range the are applicable to the polymerization of other ole iins, including normal oleñns and diolefins, by means of other combinations of apparatus and operating steps and by means of liquid polymer izing catalysts and operating conditions other higher temperatures apparently favor rapid poly than those referred to speciñcally. . merization reactor suii‘ìcient to prevent vaporiza tion of isobutane at the reaction temperature. ` merization with the formation of a high propor tion of isobutylene dimers. ' `‘The use of isobutane as the heating fluid re quires the application of pressure on the poly l ` Referring to the drawing, the polymerization reaction is carried out in reactor I which is an The vapor pressure of isobutane at 170° F. is 170 } elongated lead lined, acid-brick lined cylindrical 60 pounds per square inch (gauge) ,whereas at vessel adapted to withstand the application of substantial pressure. Preferably, reactor I is filled with some suitable acid resistant packing 210° F. it is 275 pounds per square inch (gauge). When using isobutane _as the heating fluid the vapor pressure of this material at »the reaction such as ceramic Raschig rings. The interior'of reactor I communicates at one end thereof with a lead lined mixing nozzle 2. temperature selected represents the minimum . 'The acid-isobutylene Vextract is supplied to the operation through line 3 which connects with mixing nozzle 2. Line 3‘ is provided with a pump pressure `at which it is advisable to> operate the polymerizing reactor. When employing normalv butane as the heating fluid somewhat lower pres sures may be employed, these being governed by .the vapor pressure of isobutylene at the reaction temperature. The vapor pressure of isobutylene at 170° F. is 160 pounds per square inch (gauge) whereas at 210° F. itis 255 pounds per square 4 for introducing the extract into nozzle 2 against the pressure maintained in reactor I. The heating fluid is introduced in the system through line 5 which is provided with a pump 6. inch (gauge). The vapor pressure of isobutylene Line 5` connects with an accumulator 1 from. 75 at the selectedY reaction v,terilpereiilre is the which .the heating fluid is transferred to .mixing 2,4osg725 mum pressure at which it is. advisable to operate polymers-from the tertiary butylaloohol and ter tiary butyl esters, -which are the forms in which the isobutylene is retained in the extract, occurs .the reactor when employing as .theheating fluid nor-mal butane or `.any other material-havinga Vapor pressure lower than that of isobutylene. through reactions which are endothermic. The vapor pressure of the isobutane, »or isobutyl It would beexpected, therefore, that the occurrence ene, at the reaction temperature >is higher than the Vapor-pressure of the reaction mixture, be of such reactions :in the mixture as the latter flows through the elongated reaction ‘zone would lower the temperature of the reaction `mixture progressively along the path of iiow of the re actants. However, the initial heating ofthe ex cause of .the presence therein of lower boiling ma terials, such as polymers and normal butane. However, the vapor pressure of the isobutane-or isobutylene may be taken as a satisfactory mini tract by admixture thereof with the Vaporized mumfor thepressure in the reactor. Preferably, isobutylene results in the regeneration of isobu tylene as such from the extract. The reactions by which such regeneration-occurs also are endo thermic, so that a portionof the heat supplied at the point `of mixing of rthe isobutylene and ex the pressure on the reactor should be maintained somewhat above the indicated minimum. For example, when using isobutane as Ythe heating lluid the operating pressure at 170° F. should be about 200 pounds per square inch (gauge), where .tract is absorbed bythe endothermic ‘reactions resulting in the release of isobutylene. However, isobutylene thus released polymerizes to di-iso As pointed out above, the heat required to poly merize a given quantity of isobutylene is greater 20 butylene during the passage #of-.the reaction mix fas at 210° l-T'. it should be about 300 pounds per square inch (gauge) . ture through the reaction zone. This reaction-is when the concentration of isobutylene in the ex highly exothermic and serveswto supply the >heat tract is relativelylow. The amount of isobutane, which is absorbed by the reactions by which di or other heating fluid, which must be injected into mixing nozzle 2 is aiïected also by the tem 25 isobutylene is produced directly from the tertiary butyl alcohol and tertiary butyl esters contained perature of the extract flowing through line 3, in the extract. Consequently, once the reaction .the polymerizing `temperature selected and the mixture is heated to the desired reaction temper temperature of the vap-orized heating íiuid intro duced into mixing nozzle 2. ature by the cooling> and »condensation of the vaporized isobutane the reactions resulting in the The latent heat of condensation of isobutane , formation of nii-isobutylene `apparently do not Varies from 112 B. t. u. per pound of »isobutane »at absorb or generate sufûcient heat to affect ma `a pressure of 200 pounds per square inch (gauge) to 118 B. t. u. per pound of-isobutane at a pressure terially the temperature of the reaction mixture. In the preparation ofv cli-.isobutylene for hydro of 300 pounds per square inch (gauge). Addi tional heat may be made available to the reac 35 genation to iso-octane it is desirable, for obvious reasons, to operate under conditions which pro tion zone from the isobutane by superheating the mote the >formation of dimers and minimize the isobutane vapors or by cooling the liquid isobu formation of trimers. It is found also -that tane from its boiling point to the reaction tem dimers are preferable to trimers in a polymer perature. The vari-ation in the quantity of iso butane required for various operating conditions 40 feed for an alkylation operation process `since the consumption of acid `in the alkylation process is and various-concentrations of isobutylene in the lower when alkylating dimers than when alkyl extract When the extract ñowing through line 3 is supplied to mixing nozzle V2 at 95° F. »and when ating trimers. It is desirable, therefore, to heat the reaction mixture rapidly `to a relatively high the Vaporized isobutane is supplied to the `mixing nozzle 2 through line 8 at a temperature of 300° F. , polymer-ming temperature, limit the holding time may be summarized in the following'table: at the polymerizing temperature to that neces sary to effect maximum formation of Vdi-isobu Mol ratio of H2S042C4H8 in extract 0.75:l.0 tylene, and then'quickly lower the temperature 1.0:l.0 of the reaction mixtureto the point `at which Polymerization temperature, ° F ____________ ., `17‘5 210 175 Polymerization pressure, pounds per square inch (gauge) _______________________________ _, 200 300 200 300 Heat available per pound isobutane, B . t. u_„_ 185 Pounds of isobutane required to polymerizo 150 185 ` 150 polymerization -is substantially inhibited. 210 ' 50 each pound oi isobutylene to cli-isobutylene. 1.23 1.89 1.45 2. 28 E The Vaporized isobutane and extract are inti mately mixed by suitable contact means in mix `When operating in this manner it is'desirable that the reaction mixture emergingY from reactor l be cooled rapidly to a temperatureV at which polymerization is substantially inhibited. Slow cooling maintains the mixture for an vexcessive 55 period of time in the relatively low range of polymerizing temperatures at which formation ing `nozzle 2 whereby the isobutane is condensed of trimers is favored. Such rapid 'cooling of the and the resulting mixture is brought to the pre reaction mixtureY may be acc‘omplished'by‘any selected reaction temperature. The reaction mix suitable means. It is preferred, however, in this ture then flows through the elongated reactor l 60 process to eifect'such rapid cooling by 'quenching at va rate which providesthe holding time neces with a 'cooling iiuid the 'reaction' mixture emerg sary to effect substantially complete polymeriza ing from reactor I to a temperature ’suiii'ciently tion of .the isobutylene. Necessarily, the holding low to minimize corrosion in “equipment through time in reactor I will be governed by vthe poly which the mixture passes subsequently. Any merizing temperature since this reaction pro 65 suitable'i‘luid may be used for this purpose, the ceeds at higher rates, the higher the'temperature. requirements of such a fiui'dib‘e'ing substantially Within the range of »conditions set forth above a the same as those set forth 'above for the heating holding time of 15 minutes ordinarily will be the iiuid except that materials which would be less maximum time required, and a holding time of 3 desirable Aas heating Yiîuids because of their 're to 5 minutes ordinarily is found to be preferable. 70 activity at the-highertemperatures-may be> used The temperature of the reaction mixture ñow to quench the reaction mixture. Conveniently, ing through the reactor varies but little‘from the the same fluid employed "for heating 4purposes initial temperature assumed bythe reaction mix .ture formed by the rapid and-intimate mixing ofthe isobutane and extract. -The form-ation of also may be employed as the quench. -In the specific example illustrated -i'n the ¿drawing Ya portion of the Visr’ib'utane supplied through line 8 2,408,725 The polymer product of the process is with drawn from the lower portion of fractionator 28 through line 36 for further handling. This ma terial may be used directly as an ingredient of is diverted therefrom through line II. Cooling means I2 may be provided in line II if desired to chill the isobutane to a still lower temper `ature prior to the use thereof as the quench. motor fuel but preferably is hydrogenated prior >For rapidand intimate mixing of the reaction mixture and the quench iiuid a mixing nozzle I3, which is preferably lead lined and may bev sim to such use. This material also may be em ployed as feed stock for an alkylation process. If the polymer product is to be employed in an alkylation process and if isobutane is employed ilar in construction to mixing nozzle 2, is pro vided at the exit of reactor I. Line II connects 10 as the heating and quenching fluid in the poly with mixing nozzle I3 in order to supply the merization process it may be desirable to elimi liquid isobutane for quenching the hot reaction nate the fractionation step carried out at 28. mixture as it emerges from reactor I. All or a portion of the material flowing through A suin cient quantity of the cooling fluid is preferably line 21 may be diverted therefrom throughline 31 for passage directly to an alkylation reactor. supplied through line II so that the resulting 15 Cooling means 38 may be provided in line 31 to mixture thereof with the reaction products will have a temperature of from 120° to 150° F. reduce the temperature of this material to that of The quenched mixture in mixing nozzle I3 is withdrawn therefrom through line I4 which con the alkylation reactor. When operating in this manner the isobutane required for heating and quenching in the polymerization process may be nects with a cooler I5 for cooling the mixture to a still lower temperature. Cooler I5 conven 20 recovered from the alkylation process as a portion of the isobutane normally recycled in that process. Aiently takes the form of a coil I6 maintained in indirect heat exchange with cooling water. The mixture passing through coil I6 is cooled preferably to a temperature of about 100° F. `and emerges therefrom into line I1 which con nects coil I6 with a settler I8. 1. In the method of converting olefin hydro carbone in which olefin hydrocarbons are ab 25 sorbed in an acid polymerizing catalyst at tem Settler `I8 may be operated at the same pressure as cooler I5 and reactor I, but if a lower pressure is desired peratures below polymerizing temperatures and the extract thus obtained is heated under pres sure to a temperature sufficiently high to poly merize the absorbed ole'ñns in the liquid phase, a valve I9 may be provided in line I1 for the 30 the improvement which comprises mixing said necessary release of pressure. In settler I8 the mixture of polymer and acid is permitted to separate into a lower acid layer extract while at a temperature below polymeriz ing temperatures and at the polymerizing pres hydrocarbon layer. The regen sure with hydrocarbon vapors comprising at least erated acid constituting the acid layer is with 35 a substantial proportion of an isoparaffin hydro carbon boiling above the polymerizing tempera drawn from settler I8 through line 20 for return - and an upper ture at the polymerizing pressure in proportions to the olefin extraction operation. The hydro which produce a resulting> mixture of extract and carbon layer including polymers and isobutane is condensed vapors which is at the desired polymer withdrawn from settler I8 through line ZI which izing temperature, separating from the resulting connects with neutralizer 22. 40 polymerized product regenerated acid catalyst ` In order to neutralize the acid content of the hydrocarbon mixturev flowing through line 2l and a hydrocarbon mixture comprising the poly mers and the isoparafñn hydrocarbon, recycling alkali is introduced into the mixture through line said regenerated acid catalyst to said absorption 23 which connects with line 2|. The hydro _ carbons and alkali are intimately mixed by pas 45 step, and subjecting said hydrocarbon mixture comprising olefin polymers andthe iso-paraffin sage thereof through mixing nozzle 24, and the resulting mixture is then permitted to separate hydrocarbon to alkylation reaction conditions. separa-tes as a lower phase and is withdrawn 2. In the method of converting relatively low boiling oleiin hydrocarbons in which such low ' The alkali through line -25. If desir d a portion of this 50 boiling oleñns are absorbed in an acid polymer- .f izing catalyst at temperatures below polymerizing material may be recirculated through line 2E temperatures and the extract thus obtained i is which connects line 25 with line 23. Theneu heated under pressure to a temperature suñi tralized hydrocarbon mixture which separates in ciently highV to polymerize the absorbed oleiins therefrom through line 21 which connects with 55 in the liquid phase, the improvement which com prises mixing said extract while at a temperature fractionator 28. neutralizer 22 as an upper layer is withdrawn The hydrocarbon mixture may be preheated below polymerizing temperatures with hydrocar as desired by heating means 29 located in line bon vapors comprising at least a substantial pro portion of an isoparaflin hydrocarbon boiling not 21 prior to its introduction thereof into frac tionator 28. In fractionator 28 the hydrocarbon mixture is subjected to fractionating conditions adapted to separate overhead the isobutane em ployed as the heating and quenching fluids as ywell as accompanying materials of similar boiling 60 Ysubstantially lower than saidabsorbed olefinsin proportions which produce a resulting mixture of extract and condensed vapors which is at the desired polymerizing temperature, maintaining the pressure on the mixture undergoing polymer ization sufliciently high to maintain said oleiins characteristics such as unconverted isobutylene. 65 and condensed vapors substantially Kcompletely in This material passes overhead from fractionator a liquid condition, separating from the resulting 28 through line 30 which is provided with con densing means 3| and which connects with ac cumulator 32. From accumulator 32 the con polymerized product regenerated acid catalyst lator 1 whereby material flowing therethrough 'is sorption step, and subjecting said hydrocarbon and a hydrocarbon mixture comprising olefin densate is withdrawn through line 33 provided 70 polymers and said isoparaflin hydrocarbon, re cycling said regenerated acid catalyst to said'ab with pump 34. Line 33 connects with accumu mixture comprising oleiin polymers and said iso paraflin hydrocarbon to alkylation reaction con 33 may be diverted to line 35 and returnedy to 7,5 ditions.. returned forreuse as heating or quenching fluid. Av portion of thek condensate-flowing through line the ,upper portion of >fractionator .28 as reiiux. 2,40857252 12 3.' In the method of converting butene in which butene is absorbed in an acid. polymerizing cata sorbed oleiins in the liquid phase, the-improve ment> which comprises mixing said-extractv while lyst at'temperatures below polymerizing tempera at a temperature below polymerizing temperatures and the extract thus obtained is heated tures and at the polymerizing pressure with >vapors under pressure to a temperature suinciently'high to `polymerize the absorbed butene in the liquid Cu of an isoparafñn hydrocarbon boiling above the polymerizing temperature at the polymerizing` phase, the improvement which comprises mixing pressure in proportionsl which produce a resulting saiotextract> while at a temperature below poly mixture of extract and condensed isoparafñn hy' pressure with hydrocarbon> vapors comprising at li) drocarbons which is at the desired polymerizing temperature, permitting the mixture to remainat least a substantial proportion of isobutane in pro the polymerizing temperature-for a-time sufncient portions which. produce` a resulting; mixture of to effect the desired polymerization' and regenextract and condensed hydrocarbons which is at mer-izing temperatures and at the polymerizing theadesired` polymerizing temperature, separating from the-resulting, polymerized product regener ated acid catalyst and a hydrocarbon mixture comprising butene polymers and isobutane, re cycling said regenerated acid catalyst to said ab sorption step, and subjecting said hydrocarbon mixture comprising isobutane and butene poly 15 erate the polymerizing catalyst, thereafter sepa rating the resulting mixture of isoparañin» hydro. carbons and olefin'polymers from the accompany ing acid catalyst, recycling acid catalyst thus sep arated to said absorption step, and subjecting' the said hydrocarbon mixture- of isoparamn hydro carbons andoleñn polymers to alkylation reaction conditions. 20, mers to alkylation reaction conditions. 7. The method of treating a hydrocarbonmix 42 In the methodof converting butenein which ture comprising normal olei’ins- and iso-oleñns butene is absorbed in an acid polymerizing cata which` comprises contacting said mixture with an lystat temperaturesxbelow polymerizing tempera acid polymerizing catalyst at temperatures below tures and the extract thus obtained is heated polymerizing` temperatures and sufficiently low to under pressure to a. temperature sufficiently high absorb a portion only- of said oleñn hydrocarbons to polymerize the absorbedv :butenel in the liquid phase, the improvement which comprises mixing said'extract while at a temperature below poly predominating in iso-oleñns, separating the re sulting extract from unabsorbed hydrocarbons, mixing with said extract whileat a temperature pressure with isobutane vapors in proportions 30 «below polymerizing temperatures and at the poly merizing pressure with vapors of an isoparaiiin which produce aresulting mixture of extract and merizing temperatures and at the polymerizing condensediisobutanewhich is at‘the desired poly merizing temperature, separating> from the result hydrocarbon boiling above the polymerizing tem lyst and a mixture of butene polymers and iso perature atV the polymerizing pressure in propor tions which produce a resulting mixture-of extract and condensed isoparañ‘ln vapors- which is at the butane, recycling> said'l regenerated acid` catalyst to said absorptionv step, and subjecting said‘mix the mixture at the polymerizing temperature-for ing polymerized product., regenerated acid cata desired polymerizing temperature, maintaining a time sufdcient to effect polymerization of the ture of 'butene polymers and isobutane to alkyla olefin hydrocarbons and regeneration of the acid tion reaction conditions. 40 catalyst, thereafter separating from the acid cat 5. In the method of converting butene in which alyst a mixture of olefin-polymers and isoparaf?in butene is absorbed Vin an acid polymerizing cata hydrocarbons, recyclingv said separated acid cata lyst-at temperaturesY below polymerizing tempera lyst to said absorption step, and subjecting said tures and the extract> thus obtained is heated mixture of oleñnD polymers and- isoparaiïdnr hydro under pressure to a temperature sufficiently high carbons to‘alky-lation reaction conditions. to polymerize the absorbed butene in the liquid 8. A method'for treating a-low` boiling hydro phase, the improvement which comprises mixing carbon mixture comprising normal butylenes and said extractV while at a temperature belowpoly isobutylene which comprises contacting saidmix merizing temperatures and at the polymerizing ture with an acid polymerizing catalyst at tem pressure with hydrocarbon vapors comprising at least a substantial proportion of isobutane in pro 5 O peratures suñiciently low to avoid polymerization portions which produce a resultingmixtureof extract and' condensed hydrocarbons which is at the desired polymerizing temperature, permitting the mixture to remain at thel polymerizing tem perature for a time suñî'cient to effect the desired polymerization of butene, then admixing the re action mixture with a suñicient quantity of rela tively cold liquid hydrocarbons comprising at least and eiîect absorptionv of aV portion only of said butylenes predominatingy in isobutylene, sepa rating the extract thusv obtained from` unab sorbed hydrocarbons, mixing the extract while at a temperature below polymerizing tempera ture andkv at the polymerizing pressure with bu tane vapors comprisingr atk least a substantial proportion of isobutane in proportions which produce a resulting mixture of extract and con a substantial proportion-of`isobutane to reduce the temperature of the mixture from the poly 6 O densed vapors which is at the desired polymeriz ing temperature, separating from the resulting merizing temperature to a non-polymerizing tem perature, separating from the resulting polymer' ized product regenerated acid rcatalyst and a hy drocarbon mixture comprising butene polymers andV isobutane, recycling said regenerated acid catalyst to said absorption step, and subjecting said hydrocarbon mixture of isobutane and bu tene polymers to alkylation reaction conditions. 6. Inthe method of converting olefin hydro carbonel in which oleñn hydcarbons are absorbed inan >acid-polymerizing catalyst at temperatures below polymerizing temperatures and the extract thus obtained is heated under pressure to a tem perature sumciently high to polymerize the ab polymerized product amixture of butylene poly mers and isobutane and regenerated acid cat alyst, recycling said regenerated acid> catalyst to said absorption step, and subjecting saidv mixture comprising butylene polymers and isobutane to alkylation reaction conditions. 9. A method for treating a low boiling hydro carbon mixture comprising normal butylenes and isobutylene which comprises contacting said mix' ture with an acid polymerizing catalyst at tem peratures suiîiciently low to avoid polymerization and eiïect absorption of a portion only of> said butylenes predominating in isobutylene, sepa rating> the extract thusobtained from unabsorbed 2,408,725 13 . hydrocarbons, mixing the extract while ata temperature below polymerizing temperature and at the polymerizing pressure with butane vapors comprising at least a substantial proportion of isobutane in proportions which produce a, result ing mixture of extract and condensed vapors which is at the desired polymerizing tempera ture, maintaining the mixture at the polymeriz ing temperature for a time su?licient to eiîect substantially complete polymerization of the ab sorbed butylene and regeneration of the acid catalyst, then admixing with the reaction mix 14 lyst to said absorption step, subjecting said mix ture of butene polymers and isobutane to alkyla tion reaction conditions, recovering unreacted isobutane from the alkylation reaction, and re cycling said unreacted isobutane to said poly 5 merization step. . 12. A method for processing a hydrocarbon gas produced by cracking treatment of hydrocarbon oil and containing isobutylene, normal butylene, 10 and isobutane, which comprises absorb-ing the isobutylene content of said gas in an acid poly merizing catalyst at temperature below polymer izing temperature, treating unabsorbed gas to ture a sufûcient quantity of cold liquid butane separate normal butene therefrom whereby a rel comprising at least a substantial proportion of atively paraflinic residual fraction containing iso isobutane to reduce the temperature of the mix 15 butane is produced, vaporizing at least a portion ture to a non-polymerizing temperature, separat of said residual isobutane fraction at a pressure ing a hydrocarbon mixture comprising isobu effective for polymerizing said isobutylene, mix tane and butylene polymers and regenerated acid catalyst, recycling said regenerated acid catalyst to said absorption step, and subjecting said hy drocarbon mixture comprising isobutane and butylene polymers to alkylation reaction condi tions. 20 » 10. A method for treating a low boiling hy drocarbon mixture comprising normal butylenes and isobutylene which comprises contacting said mixture with a sulphuric acid polymerizing cat alyst at 'temperatures sufñciently low to avoid polymerization and effect absorption of a por tion only of said butylenes predominating in iso butylene, separating the extract thus obtained from unabsorbed- hydrocarbons, mixing the ex tract while at a temperature below polymerizing temperature and at the polymerizing pressure with butane vapors comprising at least a sub stantial proportion of isobutane in proportions which produce a resulting mixture of extract and condensed vapors which is at the desired polymerizing temperature, maintaining the mix ture at the polymerizing temperature for a time suiìcient to effect substantially complete poly ing the isobutylene extract while at a tempera ture below polymerizing temperatures and at the polymerizing pressure with said vaporized isobutane fraction in proportions which produce a resulting liquid mixture which is at the desired polymerizing temperature, separating from the resulting polymerized product regenerated acid catalyst and a mixture of butene polymers and isobutane, recycling said regenerated acid cata lyst to said absorption step, and subjecting said mixture lof butene polymers and isobutane to alkylation reaction conditions. . 13. .In a process of producing higher boilin hydrocarbons vfrom isobutane and isobutylene wherein an absorption product of isobutylene in sulfuric acid is heated to polymerize at least a part of said isobutylene and polymers thus formed are reacted with isobutane in the pres ence of an alkylation catalyst, the improvement which comprises adding isobutane in the vapor phase under a pressure high enough to condense isobutane and supply heat for said polymeriza-v tion and to produce substantially dry isobutane and feeding resulting polymer and substantially meri'zation of the absorbed butylene and regen dry isobutane to the alkylation unit. y eration of the sulphuric acid catalyst, then ad 14. A process of producing higher boiling hy mixing with the reaction mixture `a suftìcient drocarbons from isobutane'and an ’oleñn which 45 quantity of cold liquid butane comprising atcomprises adding isobutane in the vapor phase to least a substantial proportion of isobutane to re an absorption product of said oleñn in sulfuric duce the temperature of the mixture to a non acid under a pressure between about the vapor polymerizing temperature, separating a hydro pressure of isobutane at 150° F. and about 300 carbon mixture comprising isobutane and butyl pounds per square inch at which isobutane'con 50 ene polymers and regenerated sulphuric acid cat denses and supplies heat for polymerization of alyst, recycling said regenerated sulphuric acid said absorbed oleiin and substantially dry isobu catalyst to said absorption step, and subjecting tane isproduced and contacting resulting poly said hydrocarbon mixture comprising isobutane mer and substantially dry isobutane with an al and .butylene polymers to alkylation reaction kylation catalyst under alkylating conditions. conditions. ` k l1. In the method of converting butene in which butene is absorbed in an acid polymerizing 15. In a, process of producing higher boiling ì hydrocarbons from isobutane and an oleñn wherein an absorption product of said olefin in catalyst at temperatures below polymerizing tem an inorganic acid of polymerization strength is peratures and the extract thus obtained is heated heated to polymerize at least a_ part of the oleñn 60 under pressure to a temperature sufficiently high content and polymersY thus formed are reacted to polymerize the absorbed butene in the liquid with isobutane in the presence of an alkylation phase, the improvement which comprises mixing said extractv while at a temperature below poly catalyst, the improvement which comprisesvadd ing. isobutane in the vapor phase under a pres merizing temperatures and at the polymerizing sure high enough to condense isobutane and sup (i5 pressure with isobutane vapors in proportions ply heatfor said polymerization andk to produce which produce a resulting mixture of extract and condensed isobutane whichis at the desired poly merizing temperature, separating. from the re sulting polymerized product regenerated acid catalyst and a mixture of butene polymers and isobutane, recycling'said regenerated acid cata substantially dry isobutane and feeding resulting polymer and'substantially dry isobutane to the aikyiaucn unit. ' ’ ARNOLD BELCHETZ.