US1929795A - Process for cracking hydrocarbon oil - Google Patents

Description

Oct. 10, 1933.

J. DELATTRE-SEGUY PROCESS FOR CBACKING HYDROGARBN OIL Filed March 23, 1927 ,f1 T TORNE Y.

Patented Oct. 10, 1933 I UNITED STATES PATENT oFFlcE 1,929,795 PROCESS FOR CRASIIKLING HYDROCARBON Jean Delattre-Seglly, Chicago, Ill., assignor to Universal Oil Products Company, Chicago, Ill., a corporation of South Dakota Application March 23, 1927. Serial No. 177,811 3 Claims. (Cl. 19H- 66) .This invention relates to improvements in 23 controlled by valve 24 and pass into the deprocess and apparatus for cracking oil and rephlegmator 25 where they are subjected to fracfers more particularly to a-process and apparationation in the usual manner. This dephlegtus wherein the vapor is evolved by the convermation can be helped by introduction to desion of hydrocarbon oil under heat and presphlegmator 25 of cooling mediums. Vapors 6o sure and the reux condensate formed by fracwhich remain uncondensed in the dephlegtionation of said vapors are retreated for further mater pass out of the top thereof through conversion underconditions independent from line 26 controlled by valve 27 into condenser those to which the hydrocarbon oil-was primarily 28 and thence through line 29 controlled by subjected. valve into receiver 31 which is provided with 65 In the drawing: the usual gas and liquid drawois 32 and 33 The single figure is partly a sectional and controlled respectively by means of valves 34 partly an elevational side view of an apparatus and 35. The receiver is also provided with level which can be used to carry out the process of gauges and pressure gauges not shown.

15 the invention. Referring back to the reflux condensate formed 70 Referring to the drawing, the raw oil to be in dephlegmator 25, said reflux condensate treated is charged through line 1 by means of is withdrawn from the bottomv thereof through pump 2 and through line 3 controlled by a valve line 36 leading to a hot oil pump 37 controlled 4 into a heating coil 5 as positioned in furnace by valves 38. By means of this pump the reflux 29 6 heated by furnace 7. The oil which is raised condensate can be discharged through line 39 75 in the coil 5 to conditions of temperatures and controlled by valve 40 into the upper portion of pressure suitable. to promote conversion is then the secondary treating chamber 15, wherein said passed through 1ir1e8 Controlled by valve 9 into reflux condensate is subjected to further treat reaction chamber 10, which has been shown ment in the presence of vapors evolved in the e5 as of a vertical type but may be of any other primary heating and reaction zone respectively 80 desired type- In IeaC'iOIl Chamber 10 the Oil shown at 5 and 10. The vapors evolved from.

constituents separate into liquid residue and the treatment of the reflux condensate in chamvapors. The liquid residue contains pitch and ber 15 pass off through line 23 into dephlegcoke-like particles and this liquid residue 02m mator 25 with the vapors evolved in the primary 30 be withdrawn from the reaction chamber conversion zone after they have been retreated 85 through line 11 C0Iit1`01ied by Valve 12- The in the secondary treating chamber 15. l

vapor separated in reaction chamber 10 is with- The unvaporized oil from the secondary treat drawn therefrom through. line 13 and is coning chamber 15 is withdrawn from the bottom trolled by a valve 14 whereby they are directed of the chamber through line 41 controlled by into a separately heated chamber 15. The valve 42 and is returned to the heating tubes 90 vapors may also be passed from reaction cham- 5 of the primary conversion zone after comber 10 into the separate chamber 15 through mingling with the charging stock in line 3.

by-pass line 16 in which is interposed a vapor If desired the hot oil4 pump 37 can be bypump 1'7 controlled by valves 18. passed through line 43 controlled by valve 44.

The secondary chamber 15 can be of any Also I have shown a line 45 controlled by 95 desirable type and heated by any suitable means valve 46 connecting lines 39 and 4l whereby a and I have shown in the drawing a -vertical portion of the reduxV condensatev may be rechamber heated on itsvsides and having its lower turned from dephlegmator 25 to the heating and upper ends outside the heating zone. The coils 5 without passing through the secondary sides of said chamber are heated by means of treating chamber 15. 100 combustion gases evolved in furnace 19 heated If desired a portion of Athe charging stock by burners 20 which gases pass out through hue introduced into the system by pump 2 can be 21 to stack 22. diverted into the dephlegmator 25 through line In said chamber 15 the vapors evolved in the 47 controlled by valve 48 and this portion comprimary conversion Zone of the process are forced bines with the reflux condensate in dephlegma- 105 to bubble through a pool of liquid reflux contor 25 and is thereby preheated and the mixden'sate as will hereinafter be described and the ture is treated in treating chamber 15 as heremixture of vapors and reflux condensates are inbefore described for the reux condensate. further converted, but the vapors are withdrawn As a feature of the invention the conditions from the top of chamber 15 through vapor line ,of treatment to which the vapors evolved in 110 the primaiy heating zone and the reflux condensate formed in the dephlegmator are subjected in the treating chamber 15 are preferably more severe than the conditions maintained on the primary conversion Zone. The temperature maintained in chamber 15 by A means of furnace 19 is preferably higher than the maximum temperature to which the oil was subjected during its passage through the heating coil 5 and reaction chamber 10.

Simultaneously the pressure maintained on the secondary treating chamber 15 is higher than that maintained on the heating coil 5 and reaction chamber 10 and this increased pressure can be obtained by the proper manipulation of the charging pump 2, valves 3 and 48 of the reux pump 37 and valves 40 and 46 and of the vapor pump 17 and the valve 24 on the vapor line 23, and also of valve 42 on the liquid drawoff 41 from the treating chamber 15.

By manipulation of said valves the pressure on the treating chamber 15 can be maintained higher than that on the heating coil 5 and reaction chamber 10 and at the same time the pressure on the dephlegmator 25 and the balance of the system can be the same as or lower than the pressure on said treating chamber 15.

Since the vapors and reux condensate from the material to be treated in chamber 15 are lighter than the material treated in the primary conversion zone and since to obtain further conversion in chamber 15 the temperature therein is preferably higher than that maintained through heating coil and chamber 10 the pressure in the chamber 15 is preferably higher than that on the balance of the system to prevent undue formation of noncondensible gases and coke.

I have provided chambers 10 and 15 with suitable manholes for cleaning and the chamber 15 with an additional drawoff 49 controlled by the valve 50 whereby heavy material can be drawn off from said chamber and evacuated.

The relative degree of pressure and temperature maintained on the various parts of the system depend mainly on the characteristics of the materials treated and of the products desired. It can be noted here that the more severe the conditions of temperatures and pressure maintained on the treating chamber 15, the larger percentage of unsaturates and aromatic compounds will be formed in the process,

Furthermore the conditions of temperature and pressure on the treating chamber 15 may be such as to cause a substantially complete conversion of these materials into hydrocarbon xed gases without undue formation of coke.

For instance, in one method of operation the oil in the heating coil 5 will be raised to a temperature from 700 to 900 F. under a pressure of from 300 to 500 pounds while the vapors' and reflux condensate in treating chamber 15 can be subjected to a temperature of from 950 to 1200 F. under a pressure from 600 to 1000 pounds more or less.

I claim as my invention:

l. A process for cracking hydrocarbon oil comprising raising the oil to a cracking temperature in a heating zone, delivering the heated oil to an enlarged reaction zone wherein conversion takes place, in maintaining a body of reflux condensate in a second enlarged zone, in passing the vapors from said first enlarged Zone into said second enlarged zone, in direct physical contact therewith in subjecting the vapors and reflux condensate in said second Zone to a higher temperature than that maintained in said heating zone, in subjecting vapors issuing from said second zone to reux condensation, in passing the redux condensate separated from the vapors to said second enlarged zone to supply the body of reflux condensate maintained therein, in maintaining a pre-determined superatmospheric pressure on the oil in said heating zone and nrst enlarged zone while maintaining a higher super-atmospheric pressure on the body of reflux condensate and vapors in said second enlarged zone.

2. A hydrocarbon oil cracking process which comprises heating charging oil to cracking temperature in an initial heating zone,V discharging the heated oil into a separating zone and separating evolved vapors from unvaporized oil therein, passing said vapors to a second heating zone containing liquid oil of lower boiling point than said initial heating zone wherein said vapors and oil Contact, maintaining said Second zone at higher temperature and pressure than said separating zone to effect cracking therein, removing cracked vapors from said second zone and subjecting the same to dephlegmation, and condensing the dephlegmated vapors.

3. A hydrocarbon oil cracking process which comprises heating charging oil to cracking temperature in an initial heating zone, discharging the heated oil into a separating zone and separating evolved vapors from unvaporized oil therein, passing said vapors to a second heating zone containing liquid oil of lower boiling point than Said initial heating zone wherein said vapors and oil contact, maintaining said second zone at higher temperature and pressure than said separating zone to eiect cracking therein, removing cracked vapors from said second zone and subjecting the same to dephlegmation, passing reux condensate resulting from said dephlegmation to said second zone to constitute said oil of lower boiling point, and condensing the dephlegmated vapors.

JEAN DELATTRE-SEGUY.

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