US1906863A - Coking and gasification of hydrocarbons - Google Patents

Description

May 29 w33. A, s. KNowLcs ET AL 1,906,863

COKING AND GASIFICATION 0F HYDROCARBONS Filed oct. 2o, 1927 2 sheets-sheet 1 May 2, 1933. A. s. KNowLEs m AL. 1,996,853

COKING AND GASIFICATION OF HYDROCARBONS Filed om. zo. 1927 2 sheets-sheet 2 Patented May 2, 1933 UNITED STATES PATENT, OFFICE ALEXANDER S. KNOW'LES AND CHARLES W. ANDREWS, OF CHICAGO, ILLINOIS, AS-

SIGNORS TO TAIR. & PETROLEUM PROCESS COMPANY, 0F CHICAGO, ILLINOIS, A

CORPORATION OF ILLINOIS COKING AND GASIFICATION 0F HYDROCARBONS Application led October 20, 1927. Serial No. 227,500r

This invention relates to a new and improved method for the treatment of hydrocarbons, liquid at normal temperatures or capable of liquefaction by heating. More particularly it relates to the distillation and colring of such hydrocarbons and to the new and improved creosote oil and coke produced thereby.

In the petroleum industry as well as in the making of gas and of various distillation processes there are produced large quantities of liquid hydrocarbon residues or residues capable of liquefaction by heating. The further treatment of such residues to drive oii' the remaining volatile constituents presents many practical difculties, particularly due to the fact that the solid residue derived from usual processes is a coke of poor quality-which will not satisfactorily stand transportation and cannot be used for many purposes. It also tends to pack and stick together so that it cannot readily be discharged from cars or handled.

rihese prior processes have involved the treatment of the hydrocarbons in stills where the volatilization is comparatively slow` and it is diii'icult to adequately heat the material uniformly throughoutlas the solid or semisolid residue forming in the bottom of the still serves as insulation, retarding the passage of heat.

We contemplate the use of our method in the treatment of all types of hydrocarbon residueswhether liquid or solid at normal temperatures, such as certain pitchy residues. rlhese residues are, however, capable of liquefaction at temperatures much below a coking temperature and when liquefied may be treated in a manner similar to the normally liquid residues. The method may also be used 'in the treatment of basic sludges which dier from the other types of residue mentioned but are capable of conversion into oil and coke by our method. Further materials suitable for treatment by our method are oils high in free carbon which may reach four per cent or more in some cases. .By the use of our method of treatment the oils are volatilized and the free carbon is coked. The products distilled oli are much more valuable oils than the original oil containing free carbon. Our method may also be used for the treatment of mixtures containing water so intimately mixed with the hydrocarbons as to form substantially an emulsion from which the water cannot be separated bysettlement or usual processes. In the use of our method the water is boiled od and may be readily separated from the other volatile products. l

Our method may also be used in the manufacture of high test lubricating oils from lubricating oil stock which will be distilled and higher boiling fractions will be boiled ott than are obtainable in usual processes. rl`hese fractions may be separated by the apparatus usually used in the art for separating volatile products. The heavy residue will be deposited on the oven door and coked.

Where we have used the term liquid hydrocarbons in the specification or claims, it is to be understood that the term is used as covering any or all of the materials which we have described above, or other materials having similar characteristics.

Our methods are capable of being carried out in units independent of other apparatus for the treatment or formation of the types of residues of the character suitable for operation by our method. Our methods may, howevers be used in apparatus directly associated with usual types of stills or other apparatus. "lin lthis *way heat economy may be had, for example, by using the heated products of combustion romouroven to heat the still and the heated combustion'products may then be passed to a preheating chaitber or still for driving od Water and preheating the material to be treated.

lit is an object of the present invention to provide a new and improved method and apparatus for the treatment of material of the classes described whereby the maximum recovery may be had of the volatile constituents and the solid residue may be recovered as a merchantable coke suitable forvmetallurgical uses.

It is an additional object to provide a method and apparatus of this character in which the hydrocarbon is exposed in thin vfilms. to

the action of heated gases and whereby the movement of the liquid may be selectively retarded.

It is a further object to provide a method and apparatus of this character in which the liquid residue is deposited upon a surface heated to a temperature adapted to produce a metallurgical coke.

It is an additional object to provide a method and apparatus in which the surfaces over which the liquid hydrocarbons pass are heated.

It is an additional object to provide .a method and apparatus which are simple 1n design and in use, and adapted for rapid commercial production of the volatile constituents and the coke.

It is also an object to provide a method yof this character adapted to give a high recovery of a creosote oil which is homogeneous in character and fluid and stable under normal conditions.

It is a further object to produce a merchantable coke adapted for metallurgical us, the coke being hard and dense in structure with heavy walls between comparatively large cells.

Other and further objects will appear as the description proceeds.

We have illustrated in the accompanying drawings somewhat diagrammatically eertain preferred forms of construction adapted for carrying out our improved method and forming our improved products.

In the drawings- Figure 1 is a transverse section of one form of construction;

Figure 2 is a fragmentary view in vertical section showing a modified form of construction;

Figure 3 is a view similar to Figure 2 showing a further modilication; l Figure 4 is a longitudinal section of the form of construction shown in Figure 1;

Figure 5 is a view similar to Figure 2 showing a further modification; and

Figure 6 is a vertical cross section of an additional form of construction.

Referring first to the forin of construction shown in Figures 1 to 4, the retort shown is provided with walls 11 and 12 which define a distillation and coking chamber 13. This chamber 13 contains a rotatable basket 14 supported upon the hollow shaft 15. The upper portion of the walls of the chamber 13 conform substantially to the contour of the rotatable basket 14. The lower portions 16 of the chamber walls slope outwardly toward the floor so that the area of the floor 17 greatly exceeds the area of the upper portion of the chamber and also exceeds the vertical projection of the basket 14 on the door. The pipe 18, controlled by valve 19, is provided .for the introduction of steam into the chamlber 13, if desired. The pipe 20, controlled by valve 21, is also provided and may serve for the introduction of gases for the purpose of increasing the circulation through the chamber. The rotatable basket 14 is partially filled with coke, as indicated at 22. The coke formed on the floor 17 is shown at 23.

An extension 24 of the upper portion of the chamber 13 carries a basket 25 filled with coke, this basket serving as a distributor for the hydrocarbon and also initially bringing it in contact with the gas flow; The pipe 26 provided with perforations 27, serves to distribute the liquid hydrocarbons over the basket 25. The passage 28 leads from the upper portion of the chamber 24 and serves to carry off the circulatin gases as well as the volatile constituents o the hydrocarbon being treated.

The floor or sole 17 of the chamber is heated by iues located below it, these lues serving for the combustion of gas and air. The flues 29 are fed with air from passages 30 and with gas from passages 31. These various passages serve as regenerators in order to preheat the gas and air distributed to the combustion iues 29.

As shown in Figure 4, the shaft 15 of the rotating basket 14 is hollow and provided with perforations 32 so that the shaft may serve to distribute steam or other gaseous fluids through the coke in the basket. The shaft 15 is provided with the gear 33, by means of which it may be driven and controlled. The end 34 of the chamber 13 is shown as removable in order that the basket 14 may be removed when necessary. The end 34 is provided with a door 35 through whih the coke 23 may be removed as desire The forms of construction shown in Fig.

ures 2, 3 and 5 are generally similar to that of Figures 1 and 4. The differences lie in substitution of other means for the rotating basket 14. These other means serve to perform the same function as the basket of coke 14 in that they expose the liquid hydrocarbon in thin films to the action of the gases passing through the chamber and also serve to selectively retard the movement of the hydrocarbon down through the chamber to the floor whereby the length of exposure of the liquid to the gases may be controlled.

In Figure 2 the shaft 36 is provided with a plurality of radially extending vanes 37 having the longitudinally extending troughs 38 formed upon their outer ends. As seen in Figure 2, the shaft would normally be rotated in the counterclockwise direction so that the last of the liquid would drop from the edges of the troughs as the vanes approach three-quarters of a revolution from the point where the liquid is dropped upon the vanes. Figure 3 is quite similar to Figure 2 but shows a form in which the rotating drum 39 is provided with vanes 40 hav- Lacasse ing troughs 41 formed at their outer ends. The operation of this form of construction would be quite similar to that of Figure 2.

Fi" ure 5 shows a further modification in whic the basket and pipe 26 are located reccentrically of the axis 42 of the drum 43.

This drum is provided with an unbroken outer surface 44 which is formed with 1ongitudinally extending orrugations. rlhe speed and direction of rotation of this drum will depend upon the fluidity of the hydrocarbon upon the drum and it will be seen that by this means the length of exposure of the liquid on the drum may be readily controlled.

rlhe form of construction shown in Figure 6 comprises a chamber 45 havin inwardly sloping lateral walls 46 and 47. IThe chamber is provided with the loor 48 which is heated from below. 'llhere may be also provided the lateral lues 49 and 50 whereby the lower portion of the sides of the chamber may be heated. The introduction chamber 5l is located above the chamber 45 and carries the distributing pipe 52 above the cokelled basket 53. rllhe angularly extending vanes 54, 55 and 56 are shown extending fromthe wall 47 and the intermediate vanes 57, 58 and 59 are shown extending from the wall 46. The vane 5.9 preferably terminates approximately at the center of the iloor.

V"llhe form of construction shown in Figure d does not oder the free control of the exposure of the fluid to the action of the gases as do the other forms of construction. lt provides a simple construction, however, in which the duid flows over the extended areas in thin hlms and is thus brought into contact with the gases. rlhese vanes 54fto 59 will become heated due to the heat within the chamber 45 and this heat will assist in the driving of' of the volatile constituents of the duid.

ln the operation of all forms of construction shown, it will be understood that either a hydrocarbon liquid at normal temperatures or one which may be liquefied by heating may he introduced. The Hoor is preferably heated to a temperature adapted to produce a hard dense coke merchantable and suitable for metallurgical use. rlihe upper basket of coke serves to distribute the liquid hydrocarbon upon the intermediate means in the chamber. llt also serves to cause the liquid to dow in thin films and become exposed to the gases passing through.

While we have referred to coke as carried in this basket, other means may be used, such as pieces of other material or any means for breaking hydrocarbon up into thin iilms which will beexposed to the gases. Simi-` larly, as evidenced by the forms of construction shown, the main function of the means within the large chamber is also the exlposare of large areas of thin films of the ydrocarbon to the action of the gases.

In previous methods of production of coke from such hydrocarbons, the volatilization has been carried on in large stills so that it is progressive in character, the various fractions boiling ofl in turn as the temperature rises and the distillation proceeds. In the operation according to our method, the distillation Within the chamber is not progressive insofar as the entire operation is concerned. The particles dropping to the Hoor will be at the last stage of volatilization and will give oil' the last `fractions as they are acted upon by the heated oor. Simultaneously, the lower boiling fractions are being given oli" by other drops of material in the upper basket or other contact means provided. All intermediate fractions will be continuously given off at various pointsin the progress of theliquid down through the apparatus. be a mixture of all of the various fractions.

The creosote oil thus produced has been found to differ materially from any produced by prior processes. llt is Very stable in char acter and does not tend to separate into different fractions. it remains liquid at normal temperatures and there is not the usual amount of crystallization of the fractions. While the exact characteristics of the creosote oil produced will depend upon the characterof the tar or other hydrocarbons used as the basis of the process, the creosote oil produced from one form of coal tar has been found to have approximately fifteen per cent boiling o' below 235 C., fifty-seven per cent between 235 C. and 355 C., leaving twentyeight per cent above 355 C.

The coke produced also differs very materially from the coke produced by complete distillation of similar hydrocarbons in closed stills where the liquid hydrocarbon is introduced in large quantities before the beginning of the process. Many of the lower boiling fractions are driven od before the liquid actually reaches the highly heated floor of the chamber but it is still a liquid when it reaches the iioor. lt has been found in practice that there is no objectionable deposit upon the coke in the rotating basket when that form of apparatus isused. rlhe material when it hits the door is suiciently fluid so that a substantially uniform layer of coke is formed throughout the extent of the floor and it does not build up immediately below the basket to a materially greater extent than elsewhere. It is important that the liquid reach the floor in small scattered drops or similar small quantities which may be acted upon rapidly by the heat of the floor. The coke formed is much denser than that formed in usual distillation processes and is also drier and substantially uniform in character. It is easily handled and is well adapted for rlhose volatiles carried o' will K metallurgical or other purposes where a hard dense coke is desired.

While the gases evolved from the liquid will form a considerable quantity of gas for circulation, in many cases it is found desirable to increase the circulation to effect the desired volatilization as the liquid passes down through the chamber. This may be increased by introducing steam into the center of the basket through the hollow shaft or by introducing steam through the pipe 18 which will increase the circulation in the lower part of the chamber as Well as in the basket. lf desired, other gases than steam may be used, as for example, some of the gaseous products may be recirculated through the chamber through the pipe 20 to build up the Volume of circulation.

It will be apparent that the Whole process is very flexible in character and that complete control is retained of the operation of the process. The quantity and heat of the material introduced may be varied as desired. The lengthof exposure in the chamber may be readily controlled in those forms using rotatable retarding means or such means agitated in any Way, by governing the speed of rotation or of agitation. Control of combustion in the oven flues enables full control of the oven temperatures. A further control factor lies in the composition, quantity and temperature of the gases which may be introduced to increase the circulation through the apparatus. By variation of any or all of these factors the process may be adapted readily to the material being treated and the results desired. l

While We have described and shown certain preferred methods of operation and apparatus suitable therefor, it is to be understood that this is by Way of illustration only and we contemplate such further changes and modifications as come Within the spirit and scope of the appended claims.

We claim:

l. The method of treating certain heavy hydrocarbon materialwhich comprises heating the material to a temperature sufficient to cause it to iow freely as a liquid, exposing thin films of said liquid to contact with gases heated to a Volatilizing temperature Whereby certain of the constituents are volatilized and depositing the liquid residue upon a surface externally heated to a coking tempera- .ture such that the remaining volatile constituents are driven ofl' and the residue coked.

2. Apparatus for the treatment of liquid hydrocarbons comprising a closed chamber, a substantially flat floor in said chamber, the floor being of greater area than the horizontal cross sectional area of the upper portion of the chamber, means for heating the floor from below, means for introducing liquid hydrocarbon into the upper portion of the chamber, and means for causing the liquid to flow in thin lms through the chamber and the liquid residue to be deposited upon the floor.

3. Apparatus for the treatment of li uid hydrocarbons comprising a closed cham er, a substantially Hat floor in said chamber, the floor being of greater area than the horizontal cross sectional area of the upper portion of the chamber, means for heating the ioor from below, means for introducing liquid hydrocarbon into the upper portion of the chamber, means for causing the liquid to ioW in thin films through the chamber and the liquid residue to be deposited upon the licor, and means for retarding the flow of the liquid through the chamber.

4. Apparatus for the treatment of liquid hydrocarbons comprising a closed chamber, a substantially fiat ioor in said chamber, the floor being of greater area than the horizontal cross sectional area of the upper portion of the chamber, means for heating the floor from below, means for introducing liquid hydrocarbon into the upper portion of the chamber, means for causing the liquid to flow in thin films through the chamber and the liquid residue to be deposited upon the floor, and means for causing a movement of heated gases through the chamber in contact with the liquid hydrocarbons.

Signed at Chicago, llinois, this 18th day of October` 1927.

ALEXANDER S. KNCWLES. CHARLES W. ANDREWS.

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