Патент USA US2412879код для вставки
De;- 17, 1946; ' H. G, M. FISCHER 2,412,819 CHEMICAL PROCESS Filed May 31, 1941 rzncrlolvn TING / _ COL UM/Y ~ 0541040676‘. MA TEE/Al. coknvc DRUM 14 l6 vi l 53 52 JA (K5 ‘ HEAT/N6 COIL j , COOL/NC 35 Patented Dec. 17, 1946 2,412,879 UNITED STATES PATENT'OFFICE Herbert G. M. Fischer, West?eld, N. J., assignor to Standard Oil Development Company, a corpo ration of Delaware Application May 31, 1941, Serial No. 395,920 7 Claims. (0]. 196—55) The present invention relates to the art of treating hydrocarbon oils to obtain desired prod and more particularly it relates to the ther heated oil into a chamber where the oil is main tained at the temperatures indicated and under atmospheric or superatmospheric pressure for a suf?cient period of time to e?ect the desired con version. As the process of coking proceeds in move constituents boiling up to about 700°—850° F. In processing a crude petroleum oil, the modern re?ner must deal with the crude material in a the chamber, the coke formed in the process accumulates progressively until ?nally a time is reached when the coking operation with respect manner to provide maximum quantities of de sired products, and from time to time the coin 10 to a particular chamber must be discontinued in order to remove the coke. The decoking is a mercial demand for certain petroleum products time-consuming and'laborious operation since'the may vary widely. _For example, in the northern part of the United States during the winter coke forms aistrong‘, tough mass which to com pletely' ‘remove, as stated, involves a great deal of labor. 15 readily obtainable from crude petro leum oil by simple distillation and, as a result, it is often necessary during the winter season to process topped crudes to recover additional quan tities of hydrocarbon oils which are suitable for domestic heating fuel On the other hand, during the summer months the commercial demand for gasoline and motor fuels may be such as to require an entirely di?erent treatment of petroleum crude oils in order to obtain the maxi mum production quantities of gasoline; Ordi ‘Usually after a coking chamber has been taken ‘0d the onstream‘ operation, it is ?rst permitted to cool, whereupon the operators remove the coke. The coke removal in the ordinary intermittent coking process is an operation which consumes considerable time and labor and, consequently, any method which will eliminate a substantial portion of the time and cost necessary to decoke a chamber would effect a material advantage. The main object of the present invention is to carry out the coking of heavy petroleum oils con’ tinuously by forming the coke in such a manner narily when a crude oil is received in a modern re?nery it is the practice to subject it to a ' that it is" highly frangible, relatively soft, and adapted to be continuously removed from the coking zone. ‘ A more speci?c object of my invention is to carry out a, coking operation in the presence of added cellulose linters, threads, sawdust, wood ?our or other cellulosic‘ material in divided form, under conditions such that the charcoal resulting from the added cellulosic material intermixes, with the formed coke and greatly reduces the When, however, the commercial demand is‘ such that increased quantities of gasoline are desirable, the reduced crude may be subjected to a thermal treatment whereby a tensile strength of the latter so that it maybe easily removed from the coking zone. 40 verted to vaporizable hydrocarbons and a ‘solid 45 coke. The coking operation, as ordinarily practiced in a modern re?nery, entails a. number of prac " Other and further objects of my invention will appear from the ensuing more detailed descrip tion'of my present invention. The present'invention will be best understood by reference to the accompanying drawing which shows diagrammatically a form and arrangement of apparatus elements in which my process may be carried into practical effect. I shall describe the process in terms of the coking of a speci?c reduced crude, but it is to be clearly understood Probably the most troublesome aspect of a coking 50 that the specific example I have chosen is ptu'ely illustrative and does not constitute a limitation operation is the removal of the coke from the of'my invention. ‘ ' coking zone. The coking operation is generally Referring in detail to the drawing, a reduced performed by heating the reduced crude to ‘a East Texas crude petroleum oil having an A. P‘. I. temperature within the range of from 800°-1000° F'., usually in a coil, and then discharging ‘the 55 gravity ‘of 18° is introduced into the system tical operating dii?culties and disadvantages. through line I. Sawdust’ of the‘ordin'ary' com‘ 2,412,879 it carbons, together with light and heavy naphtha, mercial grade is withdrawn from hopper l4 through star feeder i5 and conduit l1 and dis charged into the oil in line i and thereafter a and light and heavy gas o‘l. These fractions may be recovered in any known manner and usually a heavy fraction is recycled to the line I! for fur slurry of sawdust and oil is discharged by pump ther treatment in the process. A light fraction 3 into a coil 6; disposed in a suitable furnace set ting 5. In coil 4 the oil is heated to a temperature of from about 800° F. to ll00° F., and during the In may be taken off from the top of column 42 by line 43 and a heavy fraction by line 50. In order to point out the advantages of my presentinvention I may direct attention to a run which I made on an East Texas reduced crude having an A. P. I. gravity of l3°, under the con ditions hereinbefore speci?ed, in which I em order to assist in the vaporization of the oil, ployed‘ 2% by weight of sawdust and found that steam at a temperature within the range of from about 825° F. to 1100° F. is discharged into the. 7 upper part of drum 25 through line 23. Instead 8% by‘ weight of a friable, porous coke, based on the original feed, was formed. This coke was of such form and condition that it could be easily removed from a coking drum. I made a similar run with the same feed stock but omitted the heating operation the sawdust/is at least partially converted to charcoal. The heated oil is with drawn from the coil through line 5 and discharged into the top of coking drum 25 as shown. of introducing the sawdust into the liquid oil in line I, the sawdust may be introduced into the vapors in line 9, employing for the mixing of the oil vapors into the sawdust any suitable device, 20 such as an injection means. This may be accom plished by means of the by-pass 5i. Valves 52 and 53 are arranged respectively in lines ii and 5! to control the flow of the ?nely divided solid either to the heating coil or to line 9. In either sawdust, and I found that I obtained 15% by weight of coke and that the said coke was dense and hard and was difficult to remove from a coking drum. Therefore, there are two advan tages in my present process, as follows: First, the amount of coke produced from a given stock is 25 less and this means, of course, that more vapor~ event the amount of sawdust mixed with the oil izable‘ hydrocarbons are produced, which is a may be from 1% to 10% by weight of sawdust known desideratum; and, second, the coke which I produced was easily crushable and porous in and 90% to 99% oil. vaporized at least in part the case where I employed sawdust, while the The oil, ordinarily in line 9, was true when sawdust was omitted. containing sawdust and/or charcoal is then discharged 2-‘ reverse To review brie?y, the present invention relates however introduced therein, as indicated into the top of coking drum 25. The to a; continuous coking operation carried out in oil passes downwardly through the drum 25 and the presence of a friable cellulosic material, such as sawdust, the sawdust serving to form an ad during this passage it is converted to vaporizable hydrocarbons and non-vaporizable hydrocarbons. sorbent charcoal during the heating, which char coal is intermixed with the formed coke and ren conditions stated, particularly in the upper sec ders the latter readily disintegratable or crush tion of the drum represented by A. The tarry able' so- that it may be substantially continuously material thereafter continues its downwardly removed from the coking zone. A relatively small progress through the drum and the conversion 40 amount of sawdust present in the oil during coking is suf?cient to accomplish the desired continues. The heavy oil and the tar formed in the region result. I have found, for instance, that 2% by generally‘ indicated by A are converted to a weight-of sawdust based on the oil fed is sufficient frangible coke in. the region generally indicated to produce a soft coke. The sawdust which I may by B. This coke: contains the charcoal resulting from the car-bomzation of the sawdust,_ and it is 45 add may be either green wood sawdust or dry A heavy oil or tar is formed in’ drum 25 under the 35 this charcoal which forms a weak link in the structure of the coke so that the same may be readily broken into lumps and thus readily re sawdust. From a commercial standpoint, as well as from a technical standpoint, sawdust is a very desirable material‘ since it is relatively inexpen sive, constitutingto a large‘ extent a waste product moved from the coking drum. If desired, grind from saw-mills, and the like. I may of course ing or crushing means Zii may be positioned in 50 use divided cellulosic material, such as in‘ the form the lower portion of drum 25 to disintegrate and of wood flour, wood chips, wood meal, cotton reduce the coke into readily removable lumps. linters, cottonseed hulls, etc. Additional steam, say at a temperature of 825° F. The operation previously described is carried to 1100° F., mayinbeorder discharged intothethecoke drum to purge of 55 out under normal atmospheric pressure, but it is to be understoodv that my process is broad through line 30 volatile constituents. enough to be carried out under superatmosp'heric , The coke is withdrawn from the drum through pressure; for instance, pressures as high as 100 a star feeder 3! and conduit 32. Since the. coke 500 lbs/square inch in the coking zone. The issuing from the drum 25 is at anthe elevated tem .60 amount of steam, if used, may be from 5-10 mol withdrawn perature, it is desirable to force per cent and this quantity is fed into the drum 7 coke through a suitable. cooling means 35 to re 25 through lines 28 and 38' as indicated. A- tem duce its temperature. This cooling; meansv may perature of‘ about l100° F. in coking drum 25 gives consist of water, or any other cooling ?uid which excellent results. . may be circulated in a jacket surrounding con Many modifications of my invention will be be sprayed directly on the 65 apparent to those who are familiar with this duit 32, or which: may not coke. The cooled coke is then discharged particular art. into a receiving" bin is at a temperature such What I claim is: r that it will not ignite upon exposure to the air. 1. A continuous method of. producing coke Ordinarily a safe temperature would beone below 70 which is frangible and easily disintegrated, com 300° F. to 325°v F. > The vapors formed in the coking drum 25 are prising the coil preheating of a heavy petroleum oil to coking temperature but without substantial coke formation, commingling a cellulosic mate rial with the preheated oil, passing the com withdrawn overhead through line 41 and deliv ered to a fractionating column 112. Ordinarily the coking operation results in the production of ‘75 mingled» preheated oil and cellulosic material into 5-25% of gasoline and. normally gaseous hydro 2,412,879 r a zone wherein coke is formed, continuously dis1% to 10% of cellulosic6material with a reduced integrating the coke, adjacent a point of withcrude petroleum oil and heating the mixture to drawal from said zone, and continuously remova temperature within the range of from about ing coke therefrom. 1" 800° F. to 1100° F., thereafter discharging the oil 2. A continuous method of producing coke‘ u and cellulosic material into a coking zone, per which is frangible and easily disintegrated, committing the oil and cellulosic material to remain tinuously disintegrating the admixed coke and charcoal adlacent a point of withdrawal from said Zone, and Continuously removing the admixed 4 The process set fOl th in claim 3 in which the cellulosic material is sawdus 5. The process set forth in claim 3 in which the coke and charcoal therefrom. cellulosic material is wood ?our. ‘ 3. A continuous method for converting ther- 20 6. The method set forth in claim 3 in which the mally a relatively heavy petroleum oil residual into vaporizable hydrocarbons containing subStantial quantities of gas 01'1 and coke-forming constituents, Whlch process is characterized by coke and charcoal mass are ground and then recovered from the coking Zone. 7. The process set forth in claim 3 in which the cellulosic material is sawdust and in which the the feature that the coke produced is frangible 25 amount of sawdust is 2% by Weight of the oil. and readily crushable, which comprises mixing HERBERT G. M. FISCHER.