Патент USA US2123960код для вставки
‘@Fuäy H9, i938. Q H. c. PENNRICH 2,323,960 METHOD OF CRACKING HYDBOCÀRBON OILS l Filed Aug. 29, 1935 22 IO s ’ >l5 Separ?or " ’ . 2.3 f4 Mafhaneœw ,3 ' » y ^ 9 5 Ceo/@r ____/\/7\ __ _' .y Dls?l/la?ion Tower y Tar Flash Tawer ` 4: _’ Frasi? F‘œed i' Fresh?'eed 2 k„Il y ‘QÖQIa .n è@2l , Cracking l Zone . @as s - Hea?lng 2mm ' l2 „I7 ' , r @Il Haarmg Z one i ,à INVENToR. Henry C. Pennrlch. #5%. 2,123,960 Patented July 1.9, 1938 NITED STATES PATENT OFFICE 2,123,960 METHOD 0F CRACÉKIÈG HYDROCARBON Henry C. Pennrlch,-Brussels, Belgium Application August 29, 1935, Serial No. 38,362 5 Claims. This invention relates to the cracking of hydro carbon oils and it refers more particularly to the production of motor fuels having high antiknock values. » In my former applications, Serial No. 610,346, originally ñled May 10, 1932 and Serial No. 633,551, ñled September 17, 1932, a method of cracking hydrocarbon oils is disclosed, in which normally incondensable hydrocarbon gases, ob 10 tained as a byproduct of the cracking and fol lowing distillation of hydrocarbon oils, are sub jected to high pressure and temperature and are admixed to the fresh charge oil to be cracked under conditions wherein the reaction time and temperature of the oil cracking process are care fully controlled. An improved gasoline is thus produced at a distinctly higher yield and with considerably lower gas formation. Under the above conditions, many of the com 20 pounds present in the cracked gases undergo conversion and form normally liquid hydrocar (Cl. 196-9) ucts from these and the fresh hydrocarbon oil products with which they are mixed. In gen eral, the results of this process are a greater gasoline yield, less gas formation and a smoother reaction and performance of the cracking proc- 5 ess; this may in part also be attributed to the' greater amount of heat available due to the exothermic character of the reaction of poly merization and the more highly concentrated 10 gas mixture. 'I'he method of 'separating the low molecular or fixed gas constituents from the cracked gases' can be carried out in a variety of ways but in practice the following process was found to be most convenient and economical. A mixture of 15 vgasoline and cracked gases obtained by distilla tion is brought toa pressure of about 150 pounds per square inch and a temperature at which the gasoline is completely liquefied. Under these conditions, the higher boiling gas constituents are dissolved while a gas 4rich in methane and hydrogen remains unabsorbed and `is removed. the polymerization of unsaturated hydrocarbons , The solution is then heated whereby the dissolved present or formed from saturated constituents gas constituents are again set free. They are compressed, heated and passed on into the prin 25 25 by the cracking reaction. These normally in condensable gases, obtained coincident with the cipal cracking unit. One example of a practical unit embodying` the cracking operation, contain the compounds bu tane, propane, ethane and the corresponding features of my invention is illustrated in the bons. This conversion is generally the result of unsaturated hydrocarbons as well as the so-called 30 ñxed gases methane, hydrogen, carbon monoxide and carbon dioxide. It is generally found that the fixed gases‘are highly stable and generally that they do not readily undergo conversion un der the above conditions and thus it is found 35 that through the presence of the ñxed gases the conversion of the higher boiling compounds be comes incomplete. Based on these observations I found it highly advantageous to remove _the fixed gases from the 40 cracked gases before they are compressed and heated for admixture and to subject only the remaining higher boiling incondensable hydro carbons to higher pressure and temperature wherethrough they-are very readily and com ' pletely converted and thus they then form the valuable products as Yrequired for the Aabove indi cated purpose. 4 ‘ - ` Thus when the highly stable or the ñxed gases methane, hydrogen etc. are absent, then the products in the remaining mixture are present at higher concentrations and `for that reason the conversion will naturally proceed further giving a greater yield of liquid products. These conver sion products may be formed either from the gas -constituents alone or they may be reaction prod accompanying drawing and it is to be operated . as follows: . . _ 30 The fresh feed, such as a crude oil or products obtained from crude oils and similar products, enters through pipe I and is mixed with the cracked products at point 2 and from there the mixture is sent into the flash tower 3. ; Heavy tar 35 and overhead vapors are separated from themixture by condensation in the tower and it is >continuously withdrawn from the bottom by means of pipe 4. The overhead vapors are passed by means of pipe 5 'into the distilling tower 6. 40 A condensate consisting mainly of gas oil is col lected .in> the cooler 8 and is sent to the sepa rator 9.‘ The separator contains gasoline as a solvent for the higher molecular compounds and is operated at a pressure of ,150 pounds per 45 square inch 'and a gas is. separated from the liquid. -This gas comprises the ñxed'gases .and consists of methane, hydrogen, CO and CO2 and _ is withdrawn by means of pipe I3. The liquid is ~sent into the second separator. I0 by means of 50 pipe I4, in which the liquid is heated to around '300° F. under substantially the samek pressure. The heating is obtained by the use of steam cir-_ culating through the steam coil 22. A stabilized gasoline is' withdrawn into the storage tank by 55 2 2,128,960 means of pipe 23 and a gas is taken from the top of the stabilizer or separator. This gas con tains the hydrocarbons ethane, propane, butane and the corresponding unsaturates. The gas is recycled through pipe I5 and its pressure is in creased to around 1000 pounds per square inch drocarbon oil to be cracked, said hydrocarbon oil being heated to a temperature below its crack ing temperature and said mixture being in pro portions suflicient to cause cracking of apart of said oil, passing said mixture through a crack ing zone, _and maintaining said pressure on said mixture in the cracking zone, removing the mix ture from the cracking zone andadding cold fresh feed to the cracking mixture. 10 raised to around 1050° F. The heated gas is sent 2. The method of cracking hydrocarbon oils into the oil cracking zone I9 by means of. the to obtain a high-grade anti-knock motor fuel pipe I8. The pipe I1 is a bypass and contains. comprising the steps of separating from nor mally incondensible hydrocarbon gases the fixed the control valve 20. , gases methane, carbon monoxide and dioxide. The condensate of the distillation tower 6 leav 15 ing by way of pipe 'I is compressed to around ethane, nitrogen, hydrogen etc., subjecting the re 15 maining normally incondensible hydrocarbon 1000 pounds per square inch. Additional distil before the gas enters the heating zone I6. In the heating zone consisting of tubes placed in a furnace the temperature of the recycle gas is lates can be added to this stream by way of gases to a pressure between 500 and 3000 pounds pipe II. _ The stream enters the oil heating zone , per square inch and to a temperature to start I2 which consists of tubes placed in a furnace. 20 In this zone, the temperature of the oil is raised to around 800° F. The heated oil of zone I2 is mixed with the heated gas of zone I 6 in proportion to obtain a temperature of between 840 and 880° F. The 25 mixture is passed through the oil cracking zone I9 consisting of tubes placed in a furnace. The . furnace is only moderately heated in order to re polymerization but not exceeding 1200° F., and, maintaining said temperature to control said polymerization, mixing said heated gases with a hydrocarbon oil to be cracked, said hydrocarbon oil being heated to a temperature below its crack ing temperature and said mixture being in such proportion as to result in cracking of a part of said oil passing said mixture through a cracking zone, and maintaining said pressure on said mix place the heat lost during the course of the ture in the cracking zone, removing the cracking cracking process. Additional amounts of gas mixture from said cracking zone while reduc 30 may also be added into the cracking zone at >vari ing said pressure and adding fresh feed to the ' ous intermediate points along zone I9 which are mixture. ' 3. The method of cracking hydrocarbon oil to not shown. The cracking zone is made sum ciently long to assure a cracking time of around produce a high-grade anti-knock motor fuel comprising the steps of freeing normally incon 10 minutes. The temperature of the oil gas mix 35 ture at the beginning and at the end of this zone densible hydrocarbon gases of gases rich in 35 are about the same. 'I'he products> leaving the methane, ethane, hydrogen, carbon monoxide crackingzone are decreased in pressure by means and dioxide, which are diiilcult to condense and » of pressure valve 2i and from then on the pressure thereby separating from incondensible gases a will be around 200 pounds per square inch. The condensible portion, compressing said condensible portion to between 500 and 3000 pounds per 40 products are mixed with fresh charge oil enter ing through pipe I whereby the temperature is square inch and heating it to a high temperature brought to about '700° F. and then the mixture is until polymerization starts but not over 1200° F. and preventing said temperature from rising in sent to the flash tower 3. The conditions of pressure and temperature 45 may vary from those given above according to the type and kind of oil to be converted and the prod ucts desired. In general, in the heating and the cracking zones, the pressure may be between 300 and 3000 pounds per square inch while the pres 50 sures in all other parts of the operation such as in the distillation vand separation tower should be below 300 pounds per square inch. The tem perature of the oil cracking zone is to range be tween 840 and 960° F. for most of the stocks, while 55 in the gas heating zone it is to be still lower than these temperatures. Having thus described one typical example of my process, I do not bind myself to the exact details given in the above description, but rather consider this as one example illustrating the gen eral broad idea of~ my invention. - I claim: 1. The method of cracking hydrocarbon oils comprising the steps of separating normally in 65 condensible hydrocarbon gases into a nrs-t 'frac tion rich'in methane and into a second fraction order to control the polymerization products, mixing said polymerization products with nor mally liquid hydrocarbon oil heated in a heating unit to a temperature below its cracking tem perature and at the same pressure as imposed on said condensible portion and in proportions that the temperature of the mixture causes cracking, passing said mixture through a crack ing zone, and maintaining said pressure on said mixture in the cracking zone, removing the mix ture from said cracking zone, decreasing said pressure and temperature, adding fresh feed and 55 separating desired compounds from the mixture. 4. 'Í'he method of cracking hydrocarbon oil as claimed in claim 1, the step of separating the fraction rich in methane from normally incon densible hydrocarbon gases being carried out by compressing the gases at low temperature and in contact with gasoline as a solvent. removing the non-condensed gases and reevaporating the dis-_ solved gases. - - 5. The method of cracking hydrocarbon oil as claimed in claim 3; the step of separating the por substantially free from methane. heating said tion rich in methane, ethane, hydrogen, nitrogen, second fraction under a-pressure of between 500 and 3000 pounds per square inch to a tempera 70 ture sufficient to start exothermic polymerization and not exceeding 1200° F., and keeping said tem carbon monoxide and dioxide, from normally in condensible hydrocarbon gases being carried out by compressing the gases at low temperature and'in contact with saturated hydrocarbon oils l perature substantially constant whereby a fully as a solvent, removing the non-condensed gases controlled polymerization product is obtained.` and reevaporating the dissolved gases. mixing said heated second fraction with a hy HENRY C. PENNRICH.