Dec. 3, 1946. ’ i w. w. oDELL. PROCESS ^ '2,412,096 TREATING HYDROCARBONS Filed Jan. 22, 194s z sheets-sheet 1 er di/mAf-v2a1n‘me Dec. 3, 1946. 2,412,096 w. w. oDELL PROCES§ FOR TREATING HYDROCARBONS Filed Jan. 22, 1943 2 Sheets-Sheet 2 ma» Qmw Invenl‘otf Patented Dec. 3, 1946 UNITED ASTATES >l’lxTElaT ortica PROÓESS FOR TREATING HYDROCARBONS Y william w. odell, El Dorado, Ark.; assigner to' Lion Oil' Company, a corporation of Delaware Application January 22, 1943, serial No. 473,192 4 claims. (c1. 26o-_666) 2 My invention relates to an apparatus and proc ess for treating hydrocarbons. In particular it deals with thermal reactions lwhereby hydrocar bons of relatively high molecular weight yield products of relatively low molecular weight and includes cracking. More specifically the inven-` .tion has to do with the production of unsaturated hydrocarbons. and aromatic hydrocarbons from petroleum products such asnaphthas, kerosene, gasoline, fractions comprising chiefly a single hydrocarbon which may be saturated or unsatu rated. The novelty of the invention relates to Y means and method whereby particular products such as oleflns, dioleflns, and certain aromatic `can -be used eifectively if proper conditions are provided to remedy the defects enumerated. For any particular hydrocarbon there is a definite temperature above whichV it can not> be conñned in contact with iron for an appreciable period of time without dissociation or cracking occurring. In my process the hydrocarbon ’treated is heated in tubesto a temperature some what below this limit and the final desired boost in temperature ls caused to' occursuddënly by directl contact with hotter `gases in a refractory lined chamber and Ithe mixture is immediately cooled. In this manner the vapors of the hydro an excessive evolution of lhydrogen and/or car carbon being .treated are heated to the desired or optimum temperature -for -the production of butadiene. employing controllédprief time of \ bon; it alsol relates- to the economy of materials _exposure of the vapors to the action of high tem hydrocarbons can be effectively produced without ‘of construction. i ` - One of the objects of this invention is the pro duction of butadiene economically. Other objects . will become .apparent from the disclosures made herein. . _ In attempting to duplicate the results reported by numerous investigators, who presented results of laboratory studies, I ñnd lthat because of the diii'erence in ratios of pipe surface to pipe volume for different sizes of pipe the results obtained in perature While the life of the tubes or pipes in ' Ywhich the said vapors are initially heated is con served. The gases produced in the process are used in the process but I find that they *must be ‘ used in a definite manner in order to produce the _ Y desired results, which I believe to be new. ‘ A “hook-up” or flow diagram is shown'in Figure 1 which depicts one .procedure for practicing mi* ' small tubes .can not be duplicated in large tubes invention. Figure 2 shows in' somewhat greater detail and in elevation', but diagrammatically, lthe reaction chamber in which the hydrocarbon being .because of the impossibility of duplicating with processed attains its maximum, temperature; a ~ v large tubes the conditions existingwhen cracking’fifi portion of the outer _casing nis cut away to show . hydrocarbons in small-size tubes. For example, the interior in section. the ratio of outer surface area to volume capacity _ of a unit length `of 1A-inch pipe is approximately 40 to 1, whereas .that of a 11/2-inch pipe is ap In Figure 1, «the furnaces A and B` are- suitably connected with a supply of fuel and air for heat ing ythe'coils a and b which coils confine ñowing proximately 4 to 1. vaporstreams; the vapors of the hydrocarbon to _ ‘ Therefore the vapors can Y. not be heated so quickly in -a large tube at tem peratures which are attainable and which metals _ be processed pass through coil b and a portion of" the gas evolved in the `process passes through coil a. The twostreams of hot aeriform fluids will withstand, as in very small tubes such as are commonly> used in the laboratory., I ñnd that, in meet in reaction chamber I which chamber;` "the production of butadiene from petroleum 40 functions both as 'a gas mixingand reaction chamber and a- quenching chamber; the`upperA naphtha, the optimum amount ,of time that .portion Iof I is a combustion chamber for incom- _ naphtha vapors are in a 1A-inch pipe at approxi pletely burning a portion of some of‘ the gas I mately 725° C. is about one tenth of .a second evolved in the process. 'I'he quenching iiuid is whereas with pipe 2 inches in diameter it .takes the‘ heavy ends or residue from the lower portionv »much more pipe and the vapors are .thus confined of fractionator ‘which is pumped through con-._ during the heating stage for a number of seconds duit 2 to chamber I, any excess of this residue in order to reach the desired temperature; under '_ above that required as _a quenching medium is these conditions considerable cracking occurs with 'discharged through the residue conduit. _ The the production of large volumes'of hydrogen and 50 reaction products formed in the .reaction cham methane which must be cooled, compressed and berr I, along with the vaporized quench fluid, fractionally separated from the vmore valuable passes out adjacent the .bottom of I, through ' products._ The amount of this cracking is of the order of ñfty percent of the naphtha bei!! .proc conduit 3 'torfractionator _4, whereas lthe fixed gas and light hydrocarbons pass o_u-t at .the top of essed. I find that'tubes of moderately krge size 55 Iractionator'l through a 'cooler and conduit to 3 accumulatorv4 auaoee 4 main supply of quenching iluid is controlled-by the -"bottoms” or residue from i valve 89. An' oiftake 88 with control valve 94` is provided for use chieñy in starting operations, that is, hotv products of combustion may be re another portion being introduced into the naph-. moved through 33 and 8_4 when the initial heat . tha conduit I8, and the remainder passing out ing operation is` under way; valve 94- is normally through the aromatic distillate conduit. Gases closed during the operation of the process pro and vapors removed from the top of accumulator ducing butadiene. Figure 3 ‘shows in outline an 8 are conducted to compressors 8 in which they alternate method of discharging and quenching are compressed toa suitable high pressure com monly in the neighborhood of 200 pounds per 10 hot vapors from reaction chamber I, 48 being an accumulator 5 isdivided .into streams, one por -tion being/used as -a reñux in fractionator 4, auxiliary quench-fluid, conduit. square inch gage pressure. the compressed gases are then cooled and conducted to accumulator 1. Water is drawn `off from the bottom of accumu lator 'I substantially as fast as it is collected. The In the production of butadiene, practising my invention with equipment substantially as indi ‘ .cated in Figurel 1, and employing naphtha dis liquid hydrocarbons collecting in accumulator ‘I l5 tilling in the range 190° .to_substantially 400° F., I - >find that there are certain steps which must be are withdrawn and pumped to a higher pressure carefully adjusted in order to produce the desired approximating 300 pounds per square inch gage results and obtain the maximum yield of buta pressure and discharged into conduit I9; the diene. Referring to Figure 1, when the fresh vapors and gases discharged fromV the top of feed, namely petroleum naphtha, contains an ap accumulator 'I pass into absorber 8 from which preclable- amount o'f sulphur and the sulphur is the high-boiling fraction is withdrawn“ at the not removed before entering the system, sulphur bottom and pumped into conduit I9 with the gases are formed which are carried into the sys- ` high-boiling fraction from accumulator 1. 'I'he tem chiefiy'through conduit I 'I and conduit I8, lean fixed gases pass out of accumulator 8 through conduit 20 and are used for fuel purposes. Fresh 25 vaporizer 25, and coil b, although some sulphur gases are carried into the system through the gas feed stock. for example petroleum naphtha, is conduits I2 and I8. When such a naphtha is used caused 'to pass through conduit I5 to sulphur the quenching fluid in fractionator 4 becomes removal apparatus I8 from which it is discharged acid and has a- deleterious effect on results which into conduit 22 pumped to a suitable pressure, commonly about 200 pounds per square inch gage 30 seem to be caused by the tendency of the acids formed from the sulphur gases to promote poly pressure, and discharged into the upper portion meri'zation. The eil'ect of this -is manifest by a of absorber 8 functioning therein as an absorber decrease in the yi‘eld of recoverable butadiene, oil. The ñuids in conduit I9 are passed through chamberÀ I9 whereinj they are heated andthe . gumming‘of the valves in compressor. 8, and the heated fluid is conducted to the depropanizer 28. 35 deposition of solid matter of a carbonaceous nature in the lower portion of reaction chamber The vapors from the top of 23 are cooled and - conducted into accumulator II, the high-boiling - I. For the purpose of eliminating these tenden- ' v.cies it is necessary. to treat the supply of naphtha fraction from the accumulator II is discharged used in this process for the removal of sulphur ' back into the depropanizer as a reiiuxing medium whereas the gaseous fraction is discharged at the 40 compounds; sulphur removing equipment `is indi cated at I8. ` `top oi' accumulator II into conduit I2`which con ducts the major portion, approximately ninety I ilnd that when the air and gas . supplied to the combustion chamber of reaction chamber I are not carefully mixed and in pro per cent of itäto the pipe coil a in furnace A, portions whereby the air is less than sufficient the remaining ten per "cent being conducted through conduit I8 and gas-air mixing chamber 45 for the complete combustion of the gasthere l 2I wherein it is mixed with somewhat less air . is a tendency for nitric oxide to form as one of the products of combustion; when this condition exists the nitric oxide in the presence of moisture and some oxygen forms acid which is> not only'` catalytic -to the formation of polymers and gummy ’matter from unsaturated- hydrocarbons but it also- than enough for its complete combustion; the gas-air mixture from 2I is discharged into the combustion chamber of I. The high-boiling frac-` tion from the depropanizer 28v discharging from 50 the bottom thereof is cooled and passed into the debutanizer 24. from which the vapor fraction is removed at substantially the top thereof, cooled, and conducted to accumulator I4. A portion of the condensate accumulating in I4 is recirculated 55 as a refluxing medium to the upper portion of debutanizer 34, the remainder being discharged as a butadiene cut In this example, from which butadiene is recovered. IThe high-boiling frac - combines directly with unsaturated hydrocar bons. Here again~gummy matter deposits on the valves in’compressor 8 in operation. In order to avoid this condition I employ less air «than is re quired for the complete combustion of .thegas in the gas-air mixture supplied to mixing cham ber 2| and t0 the reaction chamber I; under these conditions there is no detectable amount of tion from the lower portion of the debutanizer is '60 nitric oxide in the products of combustion. The 1 discharged into conduit I‘I> from which a portion ' amount of gas recirculated through conduit Il is recirculated. after'cooling. to the upper portion of absorber 8. the remainder passing into conduit I8 from which it is discharged into »vaporizer 25;v and employed for combustion in the combustion chamber of reaction chamber I is a ratherl dell-_ nite amountrelative tothe amount _ofnaphtha ' the vapors from 2B are. conducted directly into 65 processed. Ii' an excess is used a large amountv -' of gaseous products must be cooled and com coil >b of furnace B. , pressed, which in turn calls for more equipment In Figures 2 and 3 the same system of number including compressors, and the yield of butadiene decreases. If too little gas is burned in the com lows: checker brick contact material for promot ing combustion of the gas supplied at'the top of 70 bustion chamber of I,-_t.he optimum temperature reaction chamber I is shown at 21; bustlepipes is not- attained in the reaction zone of chamber I and again thev butadiene recovery is decreased. 28 and 29 are employed for admitting` the quench Although` this optimum amount -oi! gas to be ing fluid-- and they are soconnected that either ` ` ing is employed with"additional numbers as fol 1 one can be employed alone or both used together burned is not exactly the same for all raw mate- 1 by _the proper control of valves 3| and 82; the 75 rials processed, I‘iìnd that in treating naphtha _ anaoao 5 6 as in this example the amount of gas-burned muy and causing `the not products of combus in the combustion chamber of I for obtaining 'the optimum yield of butadiene is that amount which is equivalent to less than ten per cent of the heat of‘combustion of said naphtha; I have tion to pass into the swirling mixing fluids. Pro- ' vision is made for completing the combustion -reactions in the upper portion of reaction cham ber I before the products of combustion contact been able to obtain said results with an amount the fluids from coils a and b. of gas equivalent in heating value to approxi mately 1.5 per cent ofthe heat of combustion 'may be íemployed for this purpose although I ñnd that a _checker-brick system is satisfactory; of the naphtha. checker bricks are shown> at 2l in Figure 2. . ' Natural gas or other combustible gas which is substantially lfree from sulphur compounds can be used as the fuel gas supplied to mixing cham ber 2I of-Figure 1, b'ut it should not contain a large percentage of inert matter. Gas contain Various means In the quenching operation conducted by in troducing a. .quenching fluid` into reaction cham ber I as through valves 30, 3| and 32 of Figure 2, it is only necessary-that fluid‘ flowing through reaction chamber I containing the reaction prodi ing hydrogen is particularly satisfactory because ucts be cooled to a temperature below about 600° F. It is important that the quenching fluid be of the formation of water vapor by its combus non-acid as regards mineral acids or certain acids tion. It will be noted that in using gas from ac cumulator II through conduits I2 and Il as fuel , known to promote polymerization of unsaturated hydrocarbons; phenolic acids are not of this type. gas supplied to mixing chamber 2| said fuel gas is substantially free from nitrogen, carbon mon 20 It is »found that the high-boiling residue fromv ' fractionator l of Figure 1 is a satisfactory oxide, and carbon dioxide which latter gases are quenching fluid particularly when it is main removed from the system through offtake 20 tained in a neutral or alkaline condition, namely from absorber 8. Steam maybe introduced along when deleterious acidic components of said resi with the fuel gas admitted to mixing chamber 2_I but I find that it is more satisfactory to intro 25 due are maintained at a minimum. Under cer duce this steam in the recycle gas supplied to tain conditions it develops that the addition ofv neutralizing agents to the recirculated quenching pipe coil a for two reasons, namely, to avoid the fluid is beneficial; such 'neutralizing agents in delayed combustion effect which steam causes clude ammonia, amino compounds, and certain .when mixed directly with fuel gas, and to mini mize4 the -tendency of carbon to form when the 30 nitrogen bases. When compounds of calcium, recycle gas is heated in coil a. For a given unit capacity reaction chamber I is designed to give magnesium, sodium- or similar compounds are used as acid neutralizing agents the products of the optimum time of contact of the hot products neutralization as well as any excess of the neu tralizing agent should be -removed from the from coils a and b, however, final adjustment of 35 quenching fluid before said fluid is introduced into reaction chamber I-of the figures. It is im said time of contact can be made by introduc of combustion with the hot gases and vapors ' ing the quenching fluid into the reaction cham portant to note that the use of the high-.boiling ber I at'selected levels; the reasons for this are productsl from fractional-,or 4 as quenching me dium is not a requirement of this invention, other high-boiling liquid can beused as Well. It is perhaps obvious. Means for introducing the quenching fluid into chamber I of the figures are shown at two separate levels but of course ar rangements could readily be made to provide a greater degree of regulation by the'use of inlet ports- for the quenching fluid at a greater num- l advantageous to ñrst partially cool the hot stream by vaporizing` water therein before quenching with said high-boiling liquid to avoid cracking. In the production of butadiene as outlined in ber of levels. When operating with petroleum the foregoing the yieldV of butadiene per unit of naphtha as the raw material and promoting re raw material usedl in the process is appreciably increased when butane is introduced- as one of actions favorable for the production of butadiene the time of contact of the hot gases with the naphtha vapors in reaction chamber I prior to~ vthe reactants. In processing petroleum naphtha as outlined good results are obtained, from the quenching is approximately one-tenth of one sec 50 simultaneous use of `butane, when said butane is introduced along with the recycle gas into vcoil ond at the high temperature of about 1350" F.; the lower the temperature the greater the time ` a. The yield of butadiene, when the lbutane is employed in this manner, is higher than when of contact required, Within the temperature range the same amount of butane is introduced along at which butadiene is formed. When the flow of gases, vapors, and air to reaction chamberl I are 55 with the naphtha vapor into coil l?. This is im portant and I believe a novel feature of my in. adjusted and operation is under way the fine vention. The butane used with the recycle gas adjustment of temperature in the mixing zone of may be from any source but can conveniently lbe reaction chamber I is most advantageously ob-l obtained after removing the butadiene from the tained by adjustment of the valvel in the-air sup-v 1' ply conduit to mixing chamber 2|. An effective 00 butadiene cut, 'which cut is recovered as one of ' the valuable products of reaction. Way of accomplishing this result is to employ It is desirable in the operation of this invention an auxiliary supply of air to mixing chamber 2I to heat the gases passing through coil a in fur with a thermally'operated valve which opens v nace A of Figure 1_ to as high a temperature as and closes as the temperature indicated by a 'pyrometen the thermocouple of which is located 65 practicable; one is'not only limited as to the tem perature attainable, vby the compositionof the in'the gas vapor mixing zone of reaction cham tubes employed in the construction of coil a, but ber I,'decreases or increases respectively. The by the properties of the gases passing through coil a. Cracking of the gases with the formation shown in the figures for the purpose of simplicity. It is essential in promoting these reactions at 70 of carbon in coil a is to be avoided or atleast elevated temperature-that, the gases and vapors reduced to a minimum, which minimum should represent a very small per cent of the gas passed. introduced into reaction chamber I of the figures Accordingly it is advantageous to use somev steam be thoroughly mixed therein before 'the mixture is quenched; this isaccomplished'by introducing with the recycle gas flowing to coil a. The volume the gas and vapors from coils a and b tangen 76 of steam employed preferably should not be . mechanical details of this operation are not , I ' 2,412,098 greater than the volume of gases passed there withl through coil a in the production of buta- _ diene as outlined. The steam thus used reduces the tendency for carbon to form and permits the use of somewhat higher temperatures in coil a lthan would otherwise be found satisfactory. Burning the fuel gas used, with insufiicient air ‘carbons form with the minimum amount of di oleñns; (d) the production of alcohols, glycols. aldehydes and certain other oxidation products are dependent upon arrested combustion and therefore the variables should be so adjusted that the desired amount of oxidation ìcan occur by» contacting the reactant hydrocarbon with >suiii for complete combustion of said gas, produces cient oxygen in proper dilution at the tempera ture and time of contact found to be favorable. sufficient hydrogen, which, in-contact with the hot refractory 21, reduces oxides of nitrogen to 10 It .is- possible to make styrene, indene, cyclo pentadiene and other products of similar nature lwater and nitrogen. I In the foregoing the description has been Ñdi practicing this linvention by adjusting the oper rected largely, by way of example, to the produc ating variables and supplying the proper mate tion of butadiene, which material is adapted for rial for processing. These named materials are use in >making rubber-like products and other produced in optimum amounts when all> of the materials, but it is intended that the scope ofthe aromatic distillate is returned to the reaction invention be broader than this. For example, it chamber I of Figure 1, through coil b except that is possible to produce, by changes in operating used for refluxing in fractionator I, using the procedure, temperature, raw materials, arid time - fresh charge naphtha as “make up” to keep the of contact of the fluids, such materials as naph 20 process going. They are recovered from locations in the system compatible with their boiling points thenic acids, aldehydes, alcohols, acetylene, and particular unsaturated and aromatic hydrocar and the temperature and pressure conditions pre- \ bons. Again it is possible to re-form hydrocar vailing. . bon gases byy reaction of said hydrocarbon gases Before defining my claims I call attention to with steam forming carbon monoxide and hydro 25 another particular product which can be- made ' gen. In the latter case a longer time of contact practicing this invention, in a number of dif ferent grades accordingly as the temperatures is desired than in making butadiene, hence the ' and other operating variables are altered,`namely volume of the chamber in which the re-forming carbon black. Most of the operations alluded to reactions ,occur should be larger than is _required in making butadiene. Naphthenic acids are prod 30 in the foregoing are carried out most advan ~tageously by employing superatmospheric pres-v ucts of oxidation of hydrocarbons and their` pro sure in the reaction chamber I of the figures duction depends upon the control of the tem perature, the amount of oxygen contacting the‘ ' and this pressure is of the order of fifteen to seventy pounds -gage in most cases. In the pro vapors of said hydrocarbons and the time the mixture is maintained at an elevated tempera 35 duction of carbon black the operation maybe ture. Referring to Figure 2, in the production of _ variedl appreciably fromy the above described pro cedure within the confines of my invention. For the naphthenic acids it is not necessary to pro example, combustion of a fuel gas is promoted in mote all of the combustion reactions in the top the upper portion of reaction chamber I by in lportion of reaction chamber l but on the con trary, it is preferable to promote some of the com-- 40 troducing said fuel gas and air for its combustion I through mixing chamber 2i of Figure 1. Gases, bustion in a lower zone; this is particularly true vapors, ora gas adapted to yield carbon black when the major reactanty hydrocarbons are pyrogenetically, after being preheated in the passed through reaction coils a and b shown in heating coils a and b,îare introduced into reac Figure 1. In this case'it is preferable to pass tion chamber I and into the stream of hot prod more of the recycle gas through I3 and mixing ucts of combustion passingtherethrough. Many chamber 2| ~of Figure 1 than is used in this man of the advantages of maintaining high pressures ner in the vproduction of butadiene and somewhat more steam can be used in coil _a. ,'Lower tem peratures are employed in both coils a and b when - vproducing the naphthenic acids than when pro` ducing butadiene. Without elaborating exten ' .\ `sively as to the particular products that can be do not prevail inthe production of carbon -black - particularly when the hydrocarbon reactants are Y 50 converted very largely into their elements hy made by control of .the numerous variables it drogen and carbon. In this case the hydrocar bon admitted through the ’said coils a and b may - vbe expanded into reaction chamber I and the seem sufficient to state that the products ' >resultant effluent gas stream removed through are numerous even employing a single raw ma 65 oiïtake conduit 3 may be at lower pressure than ' normally prevails in the production of butadiene. terial plus the recycle gas. - By varying the nature f. lwould of the _raw materials used a wide variety of valu able products are obtainable in employing this invention. The optimum temperature to be em ployed for any particular product can readily be 00 determined by experiment. The relative sizes of. the combustion chamber and the mixing zone of ’ reaction chamber'l of Figure 1 vary according to the products sought. For the guidance oflone The quenching fluid, making carbon, is prefer ably water and the fractionator l of Figure 1 4is in this case a carbon separator such as an electric precipitator which is operated at a tem-' perature and pressure at which water is in the vapor phase. The characteristics of carbon pro duced in :this manner vary appreciably according - to: the temperature'in the reaction chamber; skilled in the art in practicing this invention it- ' relative amounts of hydrocarbon, products of combustion, and recycle gas; the duration of the can be stated in general that (a) high’tempera elevated‘temperature in reaction‘chamber I prior ~matic compounds: (b) high temperatures of the reactions ar'e promoted in the reaction chamber ` .reactants in the said mixing zone with a very I; the amount of steam employed in the recycle gas; and according tothe adjustment of othervariables. -Accordingly the procedure of opera tion for producing carbon black can best be vde briei'~ time of contact favorthe production of un' l , period of. time the reactant gases are at the ' tures in the mixingzone of reaction chamber I and an appreciable time of contactl of the re-> actants in this zone favor the production of aro saturated hydrocarbons; (c) employing lower , temperatures in the mixing zone and an appre- _ cable time of contact in said zone oien'n hydro 75 to quenching; the pressure under which the termined by experiment. changing the operating Veficaces variables and selecting the carbon best -adapted for a particular use. - ' I Ífind that, under certain conditions, when operating with temperatures in the hot zone or . reaction zone of reaction chamber I of Figure 1 y bordering on the upper limit for producing reac tion products, the recirculation of the heavy residue from fractionator I as a quenching me 10 - ucts of combustion are mixed with the’heated vapors of the propylene stream in a mixing zone `adjacent the catalyst bed and the united stream - at a temperature approximating 1325° to 1350° F. is immediately passed through the said catalyst -bed at a'rather high velocity and immediately quenched. The time that'any given unit of the united stream is incontact with the catalyst bed is very brief, in fact, the` propylene should not dium is not satisfactory. Under these condi- tions the formation and deposition of carbon 10 be maintained at a high temperature for more occurs in the lower portion of chamber I and , than a fraction of a second in order to obtain optimum results. 'I'he gaseous products of re in the oiftake therefrom for the stream of reac tion products. 'When' attempting vto cool with ¿ ' action are removed from chamber I 'in the united A suitable catalyst for' promoting this reaction is copper, brass, and water, using the heat of vaporization of water - stream Áas outlined above. as means of absorbing the heat of the hot gaseous stream, the volume of the vapor of the evap orated water is so great that fractionator l must ' certain metals of group 6 of the periodic table. be relatively, extremely large. This diñiculty, I iind, can be overcome .by dividing the stream of hot gaseous reaction products, cooling one por tion completely, that is, to a temperaturerof about 150° F. by contact with water, immediately con tacting the cooled gas, flowing as a stream, with the uncooled portion thereof, the division of the hot gas stream being such that the final partly cooled mixture carries sufficient heat for satis factory operation of the fractionator 4. Actually satisfactory results are obtained. when the divi sion is in two substantially equal portions. Al though this procedure is no_t presented in detail in the drawings, it is shown in Figure 2 that a portion of the cooled‘y gas can be withdrawn from lA unique eñect is attained when employing a lcatalyst in the manner outlined herein. The y major portion of the heat required in the process is supplied external of the reaction chamber, namely, it is applied by heating the reactant fluids in separate furnaces while confined in pipe coils; the- reactants are brought into the reaction cham ber adjacent- the catalyst before they are ñnally heated to that temperature which is optimum for 25 catalytic reaction to occur by causing them to mix with a hotter gas just as they enter the bed of catalyst. In this manner I find it is possible to eliminate >losses due to prolonged heating at ele 30 vated temperatures and to obtain the maximum yields of valuable reaction products includingl butadiene. In this manner a minimum amount of combustion products are required in the reac tion chamber and the catalyst bed is maintained hot gaseous reaction products to be discharged 35 at an elevated temperature by virtue of the sen' sible heat of the united streams of hot gases pass from chamber I through offtake 31, and immedi-"ing therethrough. The use lof metal catalysts, ately mixed with th`e cooled gas from conduit 38. lpreferably in the form of spheres, is particularly In this procedure valve 40 is open and the mix _advantageous in practicing this invention because, ture of cooled and hot gases is conducted to the fractionator 4 in the usual manner.` 40 being good heat conductors, they help minimize local overheating and provide a more uniform It has long been recognized that catalysts can v the lower oiftake 3 y¿by closing valve 36, partly opening valve 35, and thus causing some o_f-the be effectively úsled in promoting chemical reac tions, and the applicant finds that catalysts can temperature in the catalyst bed. - Somewhat summarily but for the purpose of y clearness the major steps of the operation of this also „be effectively used in employing his inven tion. Many high temperature reactions occur 45 invention are brieñy presented as follows: Refer substantially as well or as completely without „ ring to Figure 1, employing petroleum naphtha as catalysts as with them, although this is not strictly true when maintaining the reactants at high temperatures for very brief periods of time. .the initial raw material, the said naphtha is treated for the removal of sulphur compounds in Accordingly, it is advantageous, under certain sets of conditions, to employ suitable catalysts in introduced into the system preferably at the upper 'A portion of absorber 8 wherein it is used as an ab the reaction zone of reaction chamber I of Figure sorber oil, ultimately reaching the vapnrizer 25 1 sulphur removing apparatus I6, after which it is through conduit I8; the vapors from vaporizer 25 preferably preheated are conducted to coil b in operation comprises passing the hot reactant iiuids into the reaction chamber I undercondi 55 furnace B wherein they are heated to a tempera ture below 1300" F. and preferably not over 1280° tions adapted to cause them to immediately mix F., discharging from said coil b into reaction with the freshly generated hot VproductsA of com chamber .I at a temperature preferably below bustion also produced in said chamber I and 1300" F. Simultaneously gaseous products from conducting the united streams directly into a bed of contact material, which material is preferably ' 60 the depropanizver, which gases are substantially free from carbon dioxide, carbon monoxide, hy a catalyst adapted to catalyze the reaction being drogen an'd nitrogen, are conducted as recycle gas promoted and quenching the said united stream into coil a wherein they are heated as a. stream to immediately after contact with said catalyst in a temperature above' 1300° F., the temperature said reaction chamber Í I. „ being that at which the gases can most economi For the purpose of avoiding vagueness, an 2. In other words, employing a catalyst, the 05 example of the procedure, which, it is believed, , , cally be heated without destroying valuable com ponents thereof; employing a one inch pipe as coil comes stri'ctly within theA confines of this inven a the temperature of the gas leaving coil b can be ` tion, is the productionvof butadiene from unsatu as high as 1450° F. but with larger tubes such as a 'rated hydrocarbons such as propylene. Refer ring to Figure 2 a stream of reactant ñuid com 70 two inch tube the temperature of the heated gases leaving coil b should preferably be at about 1400° _prising propylene is introduced into reaction F. The gas stream discharged from coil `a passes chamber I after first being heated in coil a to directly into reaction chamber I wherein it im a ,temperature below 1300o F. Combustible fluid mediately mixes with the hot vapors discharged A is burned in the upper portion of reaction cham ber ylas outlined above and the hot gaseous prod 75 therein from coil -b. Simultaneously combustible 2,412,096 . 11 I gas is‘introduced into the 'upper portion of the l2 4 ` , reaction chamber I and caused to burn therein said liquid passes on in the liquid phase with the gas stream, as from reaction chamber I_to irac with insuiñcient air for its complete combustion tionator 4, the design _and arrangement oi' equip and the products oi' combustion are immediately discharged as a stream into the mixing gas and vapors from coils a and b. VThe amount of gas burnedinthe upper portion of reaction chamber ment should obviously be such that conduit l for conducting the quenched gas along with anv'liq uid quenching iluid should preferably drain from I to 4 in order to prevent accumulation of liquid I being preferably that amount only which will in I. When quenching gases at high tempera give to the united stream of gas and vapors, after ture, about 1200° F..and higher, I find it is unique mixing, a temperature above 1350“ F., the opti 10 1y advantageous to use water for the first stage mum temperature varying with the product of quenching,_cooling`to -a degreewhereby the sought and the raw material employed. Em high-boiling` hydrocarbons used for the subse ploying the said petroleum naphtha as the' initial quent stage of cooling is not appreciably cracked raw material and making butadiene, the optimum in said stage. This is accomplished, referring to temperature of the united stream in reaction 15 Figure 2*, by opening valve 45 in water pipe 44, chamber I appears to be within the range 1350“ to for the ñrst stage of cooling, and opening valves 30 and 3| for .the hydrocarbon used'in the sec 1450°'F. with a time of contact prior to quenching ond stage of cooling, in which stage the gas of about one-tenth of one second, whereas with somewhat higher temperatures the time of con stream is cooled from about 1000° F. to less than , ' tact, that is, the duration of time at which the 20 600° F. united stream is retained at the high tempera Having described my invention so that one skilled in the art can practice it employing hydro ture prior to quenching, must be appreciably lower. carbons subject to thermal reaction as raw mate ' One-hundredth of one secondis suiñcient time of contact at a temperature of the order of 1500° F. 'I'he hot gas stream containing the reaction prod ucts are-- immediately quenched in the said reac tion chamber I with the suitable quenching fluid which may comprise the' heavy fraction recovered from the bottom of fractionator -4. The stream containing the reaction products is conducted to fractionator 4 and on through a separatory sys tem wherein the valuable components thereof can rial, I claim: 25 ` 1. A substantially continuous process for pro- l . moting thermal vapor phase, hydrocarbon re actions in an elongated upright reaction cham- ber containing solid contact material, comprising, passing at least one aeriform stream comprising a preheated hydrocarbon in the vapor phase suit able "for thermal reaction, at an elevated tem perature, into a reaction zone intermediate the be removed and recovered. The products which may be recovered include, besides butadiene, in ends of said reaction chamber, simultaneously in troducing into another portion of said reaction this example, benzol, vtoluol, xylol,'buty1ene and y35 chamber another stream comprising a mixture " other hydrocarbon compounds. Separate recov-l of `a combustible iiuid and oxygen in which the ery equipment is’not shown in the Figure 1 be cause invention is not claimed thereon, but it .oxygen is-somewhat less than enough for com- « seems desirable to point out that aromatic com moting combustion in the latter stream, causing f the latter stream comprising burning nuid to ' pounds are produced in this system and that they _ are separately or collectively recoverable and that plete combustion of said combustible` fluid, .pro pass through a porous bed of hot refractory solids ' their recirculation into the system as through coil in said chamber wherein combustion reactions» b of `furnace B is not necessary to the successful are substantially completed, causing the stream . operation of this invention. All of the gases and of hot freshly generated products of combustion _ vapors introduced into reaction chamber I dur ¿5to mix intimately with the nrst named stream ing the’opèration of the process are preferably> while at an elevated temperature in said 'reac admitted under superatmospheric pressurefcom tion zone whereby at least-one valuable reaction monly of the order of fifteen yto seventy pounds product is formed, immediately after a briei' re- . gage pressure. A catalyst maybe used for pro action period quenching the resultant nstream to moting the thermal reaction in reaction chamber I;1in many cases this is advantageous and infl,50 minimize polymerization, recovering from the quenched stream saidyalua-ble-product and re .others it is not required; acatalyst appears to be circulating at least a portion of the other com more eil‘ective in the lower temperature range at. bustible reaction products substantially free from which operations may be conducted than in the nitrogen, carbon- monoxide and carbon dioxide -upper ` temperature range._ The temperature of the catalyst bed 42 of Figure 2 is maintained by 55 into ‘said reaction chamber _as a part'of one ofi said streams.. virtue of the sensible heat of the fluid stream ilow 2. A substantiallycontinuous process i’or' pro ing through it; the mean temperature of the bed is usuallysomewhat lower than that of the fresh- ` moting thermal vapor phase, _hydrocarbon reac-tions in an elongated upright reaction chamber, 1y mixed, hot’gases in the united stream. It is understood that the use of a catalyst can be omitted as a part of the process without aiïecting the invention. Under certain -_sets- o_f conditions, 30 comprising, passing substantially-~ continuously a stream initially containing reactant vapor phase hydrocarbons tangentiallyl into an intermediate- particularly when there is an appreciable amount- . reaction zone of said chamber while they are at an eleva ed temperature thereby causing them to oi' coke or carbon formed and deposited in the catalyst mass it is preferable to either eliminate -65 -mix in s id zone by a whirling motionl'simulta _ the catalyst or use a. catalyst mass which provides A neously introducing into an upper adjacent com-ÃV , bustion zone of said'chamber substantially con a. less tortuous p ath than a poured bed of small- ‘ I tinuously a second stream initially comprising a size solids. mixture of- combustible gas and air, initiating ' Referring to Figure 1, it has been pointed out 70 combustion in> said second stream and passing it _ that a quenching iluid can be used, employing downwardly into a porous bed of hot contact this invention, whereby the fluid is completely _ solids conilned in said chamber thereby promot vaporized or only partly vaporized. ' en the _ing completion of combustion reactions, vimme complete heat of vaporization of the que ch liq diately passing the stream of hot combustion uid is not utilized in the quenching operation and 75 products after combustion reactions are substan Aamante y ~ 14 13 tially completed downwardly into the hot whirl ing hydrocarbon stream in said zone and causing a combined mixed stream to form in said zone having a higher temperature `than the iirst named stream but being at least at vreaction temperature, immediately passing the combined stream sub stantially continuously into intimate Contact with refractory contact material in said reaction zone forl a period of time of the order of 0.01 to 1.0 second causing reaction to occur therein forming at least one valuable reaction'product in said combined stream, immediately quenching said stream suñicient to retard undue polymerization of said product and recovering said’ product therefrom, meanwhile maintaining said refrac tory contact material at substantially reaction ` temperature by the sensible heat of the said com bined stream. 3. A substantially continuous process for pro-v " moting thermal vapor phase hydrocarbon re actions and'forming valuable reaction products in an upright reaction chamber, comprising, pass ing substantially continuously a preheated stream initially containing a reactant vapor phase hydrocarbon tangentially into an inter mediate reaction zone of said chamber, simulta- ' neously similarly introducing into said zone sub-1 stantially continuously a second preheated stream initially containing a gaseousl hydrocar bon of lower molecular weight than the aforesaid hydrocarbon along with steam thereby causing the streams to mix in said zone by 'a whirling mo tion, simultaneously introducing into an adjacent along with allow molecular weight hydrocarbon q gas, immediately quenching the latter stream in a lower zone of said chamber to retard polymer# ization of the reaction products, removing the quenched stream from'the chamber, recovering said products from the quenched stream separate from said low molecular weight hydrocarbon and returning at least a portion of the said low mo lecular Weight hydrocarbon substantially free from nitrogen, carbon monoxide and carbon . dioxide to said reaction zoneas a part of said `sec- ' ond stream'. 4. A substantially continuous processA for pro moting thermal vapor phase hydrocarbon reac tions in an upright reaction chamber, which proc ess comprises continuously passing a stream con- I taining a preheated hydrocarbon vapor from an external source into a mixing zone located inter- 4 mediate the ends of the chamber, continuously introducing into an upper portion of said cham ber another stream comprising a mixture of a combustible iiuid and oxygen, the amount of oxygen being insu?iicient to completely oxidize said. combustible material, promoting combustion in the latter stream While passingl said stream through a porous bed of hot refractory solids in said chamber until substantially all the oxygen has reacted with combustible materials, then .passing said hot combustion- products directly into the/mixing zone and causing the two streams of hot gases to commingle therein, passing the combined stream of hot gases into a reaction zone containing solid contact material located just upper combustion zone of said chamber substan below the mixing zone and reacting the gases tially continuously a stream initially containing , Ll whereby at least one valuable reaction product is premixed combustible gas and air, initiating com bustion in said stream and passing'it directly into produced, continually passing -the composite stream containing the reaction product down wardly through .the chamber from the reaction confined in said chamber thereby promoting zone and immediately after leaving the reaction completion of combustion reactions between said 40 zone quenching said composite‘stream by ad' gas and air therein, immediately ‘passing the mitting a cooling fluid into direct contact with stream ofhot combustion products from lthe up said stream, then removing the quenched stream per combustion zone into the whirling mixing ' from the chamber, recovering the valuable re streams in the intermediate reaction zone there action product from the quenched stream, sepa by heating them to a higher temperature forming rating from the stream a quantity of combustible a combined stream, immediately passing the com iluid substantially free from nitrogen, carbon bined stream substantially continuously into con monoxide and carbon dioxide and recirculating and through a porous bed of hot contact material tact with a porous bed of hot catalyst in said zone for a period of time of the order of 0.01 to 1.0 sec ond causing said thermal -reactions to occur in . said stream substantially while in contact with said hot catalyst forming said reaction products at least a portion of said combustible fluid free from nitrogen, carbon monoxide and carbon di oxide with the hydrocarbon vapor introduced into the reaction zone. ' WILLIAM W. ODELL.