Патент USA US2405395код для вставки
Aug. 6, 1946. W. H. BAHLKE ETAL 'ACETYLENE PROCESS Filed Jul'y 31, 1943 _2,405,395 , 2 sheets-sheet-l ` Patented Arias, 1,946- f A2,405,395 UNITED STATES PATENT oFFlcE wa... n. ÉÍÍÄÍÈÈÍÄÍ‘ÍÍÍÍÃ... T. C..- l penter, Flossmoor, lll., assignors to Standard Oil Company, Chicago, Ill., a corporation of In diana „ ‘ Application July 31, 1943, Serial No. 496,904: 6 Claims. (Cl. 26o-679) 1 This _invention relates to a process-»and appa fer material which is maintained in turbulent ratus for making acetylene. One object of the suspension -by .the `upfiowing vapors. The solid invention is to provide a process for making acet employed for this purpose is a refractory mate rial, generally a metal oxide, 'carbide o'r metal ylene continuously by the treatment of hydro carbon material at high temperature. Another capable of withstanding high temperatures of the object of the invention is to make acetylene from order of 2500 to 3000” F.y without fusion. Cal hydrocarbon material with better yields than cium, magnesium, or aluminum oxides, corundum heretofore obtainable from similar processes by and silicon carbide or carborundum are exam maintaining more uniform temperatures within ples. Carbon in the form of coke or graphite the critical conversion region for acetylene pro .0 may also be used. Tungsten is an example of a duction; Still another object of the invention is suitable metal winch may be used in granular to provide the heat required for the acetylene or powdered form. ' conversion reaction in a simple manner with low The reaction chamber I2 is suitably lined with - fuel cost, low heat losses and avoidance of heat refractory brick and the temperature is main transmission thru the walls of heating tubes or 15 tained at about 1800 to 2500° F. and in some reaction chambers. - cases as high as 3000° F. An operating tempera ture of 2000 to 2300° F. is preferred. Heat is The invention is illustrated by drawings which show diagrammatically in Figure 1 an appara supplied entirely by continuously introducing tus for carrying out the process in which the ‘ into the reactor I2 the superheated contact ma heating zone is positioned directly above the re 20 terial by line I6 leading from heating chamber ' action zone. Figure 2 shows a modification in I1. In chamber I'I which is suitably superim-l which the reaction zone is positioned above the heating zone. This modification is especially adapted to conducting the reaction at sub-at posed on reactor I2 the contact material isïrdi rectly heated by combustion of carbonaceous matter mixed therewith or deposited thereon. mospheric pressure. Referring to Figure 1, hy 25 Combustion is effected by a blast of preheated drocarbon feed is introduced at I0 and is pre air introduced at I8 thru'exchanger I9 and'n'o'z heated in exchanger II, flowing thence into re zle 20. The contact material is heatedli'n the actor I2 containing a turbulent solid heating preheater to a temperature well above the tem material in granular or powdered form. For our , perature of the reactor I2, for example 100 to purpose we may use almost any hydrocarbon '30 500° F. and preferably 200 to 300° F. above. as a feed stock for our process. Methane or other The contact material, referred to »hereinabove hydrocarbon is suitable, for example ethane, as a sub-divided solid material, may be a powder ethylene, propane and butane. We may also use of about 20 to 100 mesh. When using high va napthas or gas oil. Residual petroleum oils and por velocities, the contact material may be in tars' from the distillation of coal or shale may 35 granular form having grains of 1A to 116 inch or also be employed, generally in regulated amounts fed simultaneously with lighter hydrocarbons less. The settling tendency of the sub-divided solid is opposed by the lifting action ofthe up ' such as methane or other hydrocarbon gas rich flowing vapors in the reactor with the result that in hydrogen. We may also charge hydrogen contact material is maintained in suspension by to the process simultaneously with the feed and 40 the phenomenon of retarded settling. This proc for this purpose we prefer to employ hydrogenous ess results in the formation of a “dense phase” product gases separated in the process. Gas for in which the suspended particles of solid in rapid this purpose is introduced to the reactor by line motion exert an influence on one another to I3 as hereinafter described. maintain a relatively constant density depend Steam may also be introduced into the reactor 45 ing on the various factors involved, such as the I2 by line I l, the amounts being adjusted depend ing on the amount of gas recycled, the charac A ter of the hydrocarbon feed stock, and the de sired ratio of solid material to vapor. Steam and gas are preheated in heat exchanger I5, employ 50 particle size, the density of the contact material itself and the upflow vapor velocity in the reac tor. This “dense phase” will ordinarily have a density of about 10 to 100 pounds per cubic foot but lower densities of the order of 2 to 5 pounds ing for the purpose heat otherwise wasted in A per cubic foot may sometimes be encountered, the process, or heat from an outside source. In reactor I2 the hydrocarbon gases and vapors especially with solids of low specific gravity such as magnesium oxide. Densities of 15 to 25 pounds and/or hydrogen and steam flow upwardly in per cubic foot‘are satisfactory while the higher contact with the sub-divided solid heat trans 55 densities of the order of 35 to 100 pounds per 2,405,395 I cubic foot maybe encountered in _case of solids o_f high specific gravity such as carborundum and particularly powdered tungsten, 4 or ethyl acetate also lmay be used for this PUT* pose. ' . , _ The solvent is introduced into the absorber by line 42 and unabsorbed gases, principally ethanc, ethylene and propane, are discharged by vapor line 43. The‘solvent and dissolved acetylene are . One of the fundamental characteristics of the suspended dense phase reaction zone is the unl formity of temperature resulting from the rapid migration of solid particles from top to bottom conducted by line 44 to stripper 45 from which ' >and back and from side to side. As a result any acetylene is removed by line 46 while the solvent is tendency toward overheating or cooling is in-l , recycled thru pump 41 and line 42. If desired, stantly prevented fromv developing local hot zones 10 the acetylene may be retained in solution in the solvent. e. g. acetone, in which it is very highly soluble when maintained under pressure. The gases eliminated from absorber 32 by line iarly. preheated material introduced at I6 is al most instantly equalized in temperature with the I3 are comprised chiefly of hydrogen and methane material alreadyin the reactor I2. As a result 15 with a small amount of other hydrocarbon gases. the temperature thruout reactor I2 is> maintained As hereinbefore indicated, these gases may be uniform generally differing not more than 5° and recycled to reactor I2 in sufficient amount to not more than 25° F. at the maximum. maintain the desired reaction conditions for the The time required for the passage of hydro vformation of acetylene from the hydrocarbon feed or cold zones in the reactor by vreason of the rapid mixing and redistribution of heat. Sim‘i- ‘ carbons thruthe reactor is maintained short in 20 supplied by line l0._ Methane in the recycle gas order to ‘avoid secondary reactions resulting in is also converted to acetylene in the reactor. In the operation of quench tower 22, sufllcient the loss of acetylene. A reaction timeof about water or oil-quenching liquid is charged byline 0;1 to 1 second is preferred although longer reac 23 to maintain a liquid phase in the quench tower, tion time may be used, for example 5 to‘10 seconds, particularly when charging methane as the hydro 25 thereby providing a Washing action for the prod uct vapors and removing therefrom suspended carbon feed stock and when introducing substan-y tial amounts of steam and/or hydrogen. ï The . ycontact material which may be carried over from Contact material in suspension is ' reactor I2. amount of steam or hydrogen introduced with the conducted from the quench tower by line 48 lead feed stock is preferably about 5 to 50 mols per mol of hydrocarbon'introduced. ’ " 30 ing to separator 49 provided with overñow 50 for the withdrawal of oil in case water is employed The reaction products are conductedfrom` the as the quenching liquid. In case oil is employed reactor by line 2I leading `to quench tower 22' as a quench liquid, the recovered quench oil may where the temperature is instantly reduced-to a point where acetylene decomposition is slow, byl be recycled thru lines 50 and 54 back to quench> tower 22. In case water is employed for quench contact with a current of water or oil supplied by ing, it may be returned directly from the base line 23. Additional quench liquid, preferably of tower 22, with solids in suspension, to quench water, may be introduced by line 24 and directed , the reactor at 25, thus returning to the reactor into line 2I_ at the outlet from reactor I2 or Solids lost in the product vapors. The slurry from directed by valved line 25 into the upper part of reactor I2' itself above the level of kiliiidized solid 40 the base of separator 49 is conducted by line 5I to settler 52 wherein the solid contact material therein. The product gases thencefiowl by line may be removed from the quench liquid by line 26 to condenser 21 from which the water or quench l 53. Part or all of the recovered solids may be oil, and suspended solid particles escaping from recycled by line 54 for use in quenching in 22 the quench tower, is condensed and _discharged into separator 23. Accumulating oily reaction 45 or elsewhere, but where the solids have a low value they may be discarded. If desired, recovered products are withdrawn from the separator by contact material may be dried -and returned to the line 29. Uncondensed gases including acetylene reactor for further use. , are conducted by line 30 and compressor 3| to Additional contact material may be supplied as absorber 32 wherein acetylene and‘heavier hydro carbons are absorbed in an absorbing oil intro 50 makeup to the reactor-preheater system thru hopper 55 controlled by valve 56. Additional solid duced by line 33. The pressure employed in the fuel to supply heat for the process may also be absorber is suitably about 100 to 300 pounds per introduced by hopper 55, for example granulated square inch but may be much highenfor example or powdered coal or coke may thus be introduced. 1000 pounds. The rich oil withdrawn from ab- , . sorber 32 by line 34 is reduced in pressure at valve 55 Coal may also be supplied directly to reactor I2> 35 and thence enters fractionator 36, wherein acetylene and light hydrocarbons are discharged thru vapor line 31 and the denuded oil is -recycled thru line 38 and cooler 3S. The light hydrocarbon by `means not shown. Thus powdered coal may be blown into the reactor I 2 by a current of steam. ‘ In starting up operation of the process, the pre heating chamber I1 may be heated to tempera e. g. 2000“ F., by a blast of gas and air sup fraction containing principally C4 hydrocarbons 60 ture, plied by burner 51 and simultaneously contact including butadiene, butylenes. butanes ~and ' material, e. g. carborundum, may be introduced at 55 and recycled thru the system'. The contact propylene may be withdrawn by trapout line 40. material is withdrawn from the base of reactor I2-. It should be understood that the fractionator 65 and returned to the top oi' preheater I1 by a suit shown is diagrammatic and a plurality of towers, able conveyor, for example, a hot blast thru an perhaps operating at different pressures may be insulated line involving a minimum of heat loss. heavier hydrocarbons with some propane and employed. - > _ The vapors and gases withdrawn from frac ' Thus a blast of air introduced at 58 is preheated ' in exchanger 59 and injected into eductor 60 where tionator 36 by line 31 are conducted to absorber 70 the contact material is received from reactor I2 . - and carried thru line 6I to cyclone separator 62. 24| wherein a selective solvent ¿for the recovery Separator 62 serves to recover solids from the y of acetylene is employed. For this purpose combustion gases leaving heater I1'by duct 63 and alcohol, e. g. methyl, ethyl or isopropyl alcohol, also provides heat exchange between those gases may be employed. Acetone, glycol monoformate, glycol monoacetate, mono or diacetates of glycol, 75 and the solids recycled from reactor I2. The re 2,405,395 covered solids then ñow by duct 64 back to the heater I1, preferably below the surface ofthe tur charged via line 83 while recovered solids ilow> back to-the heater'by duct 84. The reheated bulent layer of powdered solids therein. In the solids, for example, at a temperature of 2500“ F., ` operation of the heater I1 the turbulent solid heat ‘ flow by line 86 back to reactor 1| being impelled by a jet of conveyor gas introduced by line 86. carrier forms a pool which continually overflows into duct I 6 leading to the reactor I 2, thereby The amount of gas required for this purpose may be only sufllcient to aerate the solids somewhat In preheater I1 it is preferred to maintain the and reduce the density of the suspension. contact material in dense phase suspension, with It is preferred to operate the heater 18 at a a density of about 5 pounds to 25 pounds per pressure slightly above atmospheric and to main cubic foot, although much higher density may 10 tain the pressure differential between the heater be employed, particularly in the case where very and the reactor 1I by means of the column of dense heat carrier solids are used. Thus with aerated iluidized solids in duct 11 which acts as carborundum, densities of 50 to 'I5 pounds per _a standpipe. In this way the tremendous ex-_ cubic foot may be employed. The heat resulting pense of exhausting the combustion gases from 15 from the combustion of carbonaceous material heater 18 is avoided. from the carrieris employed to preheat the con Having thus described our invention what we tact material to a uniform accurately controlled claim is: temperature for use in the reactor I2, thereby 1. The process of making acetylene which com stabilizing the operation of the process. prises contacting hydrocarbons with iìne granu ‘ maintaining a level resembling that of a liquid. For reasons of heat economy the hot gases dis» 20 lar solids maintained inturbulent -dense phase charged from separator 62 may beconducted by line 65 thru heat exchangers I9, ll and 59 as suspension by passing the vapors of said hydro preheater special refractory linings must be used, » by direct contact with combustion gases, main carbons upwardly through a reaction zone in indicated. Any residual solid contact material contact with said granular solids at a velocity carried away by the combustion gases may be suiiicient to provide for hindered settling of said recovered in electrical precipitator 66 orby scrub 25 solids, maintaining the temperature of said re bing with a suitable scrubbing liquid or by other action zone above .1800° F. by introducing into means. The combustion gases may then be em said reaction zone a stream of hot granular solids ployed as a low grade fuel gas and have a fuel at a temperature substantially above the tem value comparable to that of producer gas owing perature of said reaction zone, withdrawing sol 30 largely to their carbon monoxide content. ' ids from said reaction zone at the temperature It should be understood that on account of the thereof and reheating them in a preheating zone high temperatures employed in the reactor and taining the solids in said preheating zone in and where metals are exposed to the gases high melting alloys such as chrome-nickel alloys, e..g. 35 dense ?luidized turbulent suspension by upfiow ing combustion gases, maintaining an excess of Calite, Chromel, etc. may be employed. ' carbon in association with said solids beyond that In order to obtain maximum yields of acetylene, consumed by combustion in said preheating zone, it is desirable to operate the reactor at low pres maintaining a higher pressure in said preheating sures, generally atmospheric pressure or below. 40 zone than the pressure in said reaction zone, Sub-atmospheric pressures may be obtained by transferring a dense fiuidized stream-of solids operating pump 3l as a vacuum pump or ex from said preheating zone back to said reaction hauster. When conducting the reaction at sub zone through a column of suflicient height to atmcspheric pressures it is _advantageous to em ploy the arrangement of reactor and heater 45 provide a hydrostatic back pressure substantially equivalent to thel pressure diiferential between shown in Figure 2. ' said preheating zone and said reaction zone. Referring to the drawings, Figure 2, methane withdrawing reaction products from the upper or other hydrocarbon feed stock is supplied by ~part of said reaction zone and recovering acetyl» line 10 to reactor 1I maintained under diminished ene therefrom. pressure, for example 0.2 to 0.9 atmosphere. The 50 2. The process of claim 1 wherein the preheat conversion of the hydrocarbons to acetylene and ing zone is maintained at a temperature of about carbon is effected by the heat of. the ñnely di 200 to 500° F. above the temperature of said re vided solid heating medium with which the re action zone. . , actor is substantially ñlled. The reaction prod 3. The process of making acetylene by contact ucts escape by line 12 to a suitable exhausting 55 ing'a hydrocarbon vapor with a iluidized mass of and acetylene recovery system. Quench liquid hot refractory solids at _a temperature in excess may be injected at 13 and/or 14 to prevent the of 1800° F. in a reaction zone, introducing the loss of acetylene by secondary reactions at lower said hydrocarbons at a low point in said reaction temperatures. Recycled gases, e. g. methane at sufficient velocity to maintain said mass and/or hydrogen, may be introduced into the 60 zone of solids in iluidized dense phase condition, with reactor by line 15 and steam by line 16. drawing reaction products from the -upper part 'I‘he iluidized solid heating materialv in suspen of said reaction zone, transferring a stream of sion in gas overflows from reactor 1I into duct ñuidized solids from said reaction zone to a heat 11 leading to heater 18 where the temperature exchange zone where they are contacted with hot is restored by combustion with air introduced at 65 combustion gases withdrawn from a combustion 19. Additional heat may be supplied by burner zone, transferring heated solids in a ñuidized 80 when desired but generally the amount of car stream from said heat exchange zone to saidbon deposited on the heating material is more combustion zone for further heating therein by than suiiicient to supply all the heat necessary a combustion reaction, discharging combustion ` when blasted with air, and it is desirable to leave 70 gases from said heat exchange zone after con a deposit of unburned carbon on the heat carrier material to insure that the reheated material carries no oxygen back to the reactor. Combustion gases from heater 18 ñow by duct 1 - 8| to cyclone separator 82 tacting with said solids and conveying a ñuidlzed stream 'of solids from said combustion zone to said reaction zone, the vtemperature of said con veyed solids being substantially above that ot` and thence are dis` 75 said reaction zone. _ ' m p 9,405,395 , 6. The process of claim 1 wherein said reaction zone is maintained at a. pressure of about 0.2 to _' 4. process of claim 1 ’wherein 'the vapor velocity within said reaction zone is controlled to provide a suspension of granular solids having 1.0 atmospheres and the preheating zone is main tained above atmospheric pressure. ’ a density within the range ox bout'â to 50 pounds per cubiefoot. v 5. The process of claim 1 wherein the tempera ture oi' said reaction -zone is maintained within the range of. about 2000 to 2500’ F. 5 Will-IAM H. BAM. MORRIS T. CARPENTER.