US3499834A - Retorting of hydrocarbonaceous solids - Google Patents

Description

March 10, 1970 R. R. GOINS RETORTYING 0F HYDROCARBONACEOUS somns I 2 Sheet-Sheet 1 Filed Feb. 16, 1967 VAPOR mEs CRUSHING AND SEPARATING SHALE FINES FINES RECYCLE GAS FIG.

INVENTOR. R. R. coms A TTOR/VE Y5 March 10, 1970 Reel Ms RETORTING 0F HYDRO'CARBONACEOUS SOLIDS Filed Feb. 16, 1967 2' Sheets-Sheet 2 VAPOR 'FINES (RECYCLE GAS INVENTOR. R R GOINS A T TORWEKS United States Patent 3,499,834 RETORTING 6F HYDROCARBONACEOUS SOLIDS Robert R. Gains, Bartlesville, 0lrla., assignor to Phillips Petroieum Company, a corporation of Delaware Filed Feb. 16, 1967, Ser. No. 616,665 Int. Cl. Cltlb 1/04, 53/06; C10g N00 US. Cl. 20811 7 Claims ABSTRACT OF THE DISCLOSURE This invention relates to the handling of fines of hydrocarbonaceous materials which are retorted. In one of its aspects, it relates to a process for the handling of hydrocarbonaceous fines in a retort; also a method of handling or retorting larger particles or pieces of the same or compatible material undergoing retorting. In another of its aspects, the invention relates to apparatus for the retorting of hydrocarbonaceous fines.

In one of its concepts, the invention relates to a method for retorting of hydrocarbonaceous fines-containing material by selectively placing a quantity or proportion of such fines to a predetermined area or section of a retort in which larger pieces of material undergoing retorting are extant. In another of its concepts, the invention relates to such a method in which the selected place is one where temperatures are low and a second place where the fines will reduce the flow of air or vapors flowing through the bed causing the vapor front to spread out into the more porous sections of the bed.

In another of its concepts, the invention relates to an apparatus comprising in combination a vessel, at least one inlet port disposed peripherally in said vessel for feeding downwardly into said vessel solid subdivided hydrocarbonaceous material such as fines, said vessel containing a grill or screening disposed to encompass the outlet of said pipe between said grill and the peripheral wall of said vessel. In another of its concepts, the invention relates to an apparatus in which a plurality of concentrically arranged pipes are disposed within said vessel for feeding one size of hydrocarbonaceous material through one of said plurality of said pipes and another size material through at least one annulus comprised by said concentrically disposed pipes.

It has been known that economic considerations make it desirable to retort as much of mined hydrocarbonaceous materials, such as crushed shale, as possible. Thus, a minimum discard of fines has been important in efforts to render the mining and retorting of shale to produce oil therefrom in an economically competitiv market. Much work has been done with regard to the study of particle size of shale which can be retorted. This is exemplified in Bulletin 635, Bureau of Mines, Development of the Bureau of Mines Gas-Combustion Oil Shale Retorting Process by A. Martzick et al., pages 49 et seq. The methods of dealing with fines have been suggested in Patents 2,4,80,670, issued Aug. 30, 1949, E. B. Peck; and 2,647,077, issued July 28, 1953, C. E. Alleman.

Erosion as well as corrosion and other difficulties are encountered upon the physical handling of equipment, which ordinarily is metallic in character, of hydrocarbonaceous solids which physically scratch or cause attrition of the metal surface and which also, due to high temperature and acidic components of evolved vapors, chemically deteriorate or tend to deteriorate the containing vessels. It appears that the simplest operation is one in which a body of crushed hydrocarbonaceous material, e.g., oil shale, coal or other hydrocarbon-bearing earthy material, is simply batchwise or continuously retorted in a containing vessel. Special handling equipment is thus avoided. The cost of erecting and maintaining the physical plant is kept at a minimum. Nevertheless, such a plant, to be economically feasible, must have credited to it product derived from the fines if it is to be economically feasible under present day considerations of cost and possible profit. Further, there are problems as when it is attempted to retort fines and there are clinker-producing stoppages in the handling equipment. Further still, optimum benefication of the fines, be these of oil shale, coal, wood or other material, depends to an important extent upon the temperature at which these materials are destructively distilled. Accordingly, in the art, except for a few special instances where highly-refined or intricate handling has been suggested, fines have been eliminated from the crushed material prior to retorting.

I have now found that the fines of the crushed material to be retorted can be retorted simultaneously with the coarser particles and in the same vessel by very simply feeding said fines to certain preselected sections of the vessel. Feeding of fines to near the walls of the vessel where gas temperatures are, relatively speaking, low or at a minimum, will avoid overheating of the fines and avoid the clinkering thereof and will beneficiate the fines to good advantage. The fines will retort. desirably at the lower temperature in the time the larger pieces retort at the higher temperature. Thus, the process lends itself well to take advantage of temperature differences which exist. The amount of fines passing at a given point in a continuous bed operation is regulated at. will and can be different from amounts passing at points within the bed away from the wall or walls, but at the same level. Thus, I have found that not only do I have a method for beneficiating the fines, but also a method which, because of the relationship of fines within a body of coarser particles, abrogates the effect of the coarser particles against the walls of the vessel so that the walls of the vessel are protected, say against deterioration. The walls are further protected against chemical deterioration.

To the extent the fines are placed into the vessel or retort at preselected sections thereof, there will be a displacement of or at least some mixing with the coarser pieces. In the preferred operation the quantity and/or the manner of feeding the fines are designed or adjusted so as to exclude the coarser pieces to a substantial extent from said section.

Recycle gases, if any, will be introduced usually to the bottom of the retorting vessel.

I have further found that some or all of the fines can be introduced to low temperature positions of the overall bed at points which are located away from the air introduction pipes or nozzles, or other air introduction points or orifices. In this manner, the fines thusly introduced are contacted with vapors at said low temperature. The portion of the bed constituted by the fines is kept at a desired temperature and the size of the fines or the amount of them introduced regulated. Here, as in the earlier embodiment of the operation, a relative proportion of fines to coarser material can be importantly adjusted.

Still further, I have found, pursuing the overall or broad concept basic to this invention, that the fines shall be introduced to selected portions of the coarser material undergoing retorting, that the fines can be introduced to surround the air inlet port or pipe so that the fines are beneficiated or retorted, but at a place at which the flow of air tends to helpfully control the temperature of benefication. Further, here as before, the relative proportions of the fines with respect to air as well as air temperature can be importantly regulated. If desired, only a portion of the air will be introduced at the place of introducing the fines or a portion of them.

An object of this invention is to provide a method for the retorting of hydrocarbonaceous solids. Another object of this invention is to provide apparatus for the retorting of hydrocarbonaceous solids. Another object of this invention is to provide a method for retorting of hydrocarbonaceous solids fines simultaneously or concurrently with the same or other hydrocarbonaceous material of a coarser nature. Another object of this invention is to retort crushed oil shale fines. A further object still of the invention is to provide method and apparatus for the retorting of fines of various crushed materials either with coarser particles of the same or other materials.

Other concepts, objects and the several advantages of this invention are apparent from the study of the disclosure, the drawing and the appended claims to the invention.

According to the present invention, there is provided a method for retorting, i.e., the destructive distillation of hydrocarbonaceous solids fines or material containing the same which comprises introducing the said fines to a retorting operation in which a bed of coarser hydrocarbonaceous material is being retorted. Further according to the invention, the fines can be introduced at one or more of the following places simultaneously or serially to control the beneficiation thereof as well as the beneficiation of the coarser material undergoing retorting. Further according to this invention there is also provided an apparatus, as described, having at least the following features, separately or in combination: a plurality of concentric pipes as shown by 11 and 12 for feeding two different sizes of material, one through the central pipe and the other through the annulus, in the instance shown in the drawing the fines being fed centrally and the large material being fed concentrically through the annulus to accomplish at least some of the purposes of the invention. Further, according to the invention apparatus is provided for feeding fines peripherally either by way of pipes extending downwardly as at 8 and/or by pipes extending inwardly from the periphery as at 6. However, the feed must be distributed in a continuous stream around the retort. In a more specific embodiment, grill work can be provided to help guide the fines and/or the coarse material at various places within the apparatus. In the embodiment shown, the grill work encompasses fines introduced peripherally between the wall of the vessel through which the fines are introduced and the coarser material as shown.

One skilled in the art in possession of this disclosure and studying the same and applying his knowledge that temperatures across a bed in a destructive distillation usually are found to be different as one measures from point to point across the bed will recognize the advantages of this invention which need not here be belabored.

In the drawings, FIGURE 1 is an elevational view of an enlarged cross section of an embodiment according to the invention in which fines-feeding conduits are all of them located in the upper portion of the apparatus. FIGURE 2 is a similar view in which some of the pipes extend substantially down into the bed of shale or by hydrocarbonaceous solid being retorted and in which there are provided peripheral introduction pipes and annular grills or screening to assist in directing the flow of fines also as later herein more fully described.

More fully describing the invention, reference is now made to the drawing, FIGURE 1, in which 1 is a retort, to which, say, oil shale is fed by distributor 2. A bed of shale is established in retort 1 from which retorted or expended shale is removed through star valve 3. Vapors generated are taken off for further treatment known in the art at 4. In the operation shown, shale is continuously introduced at 5 and distributed by distributor 2, and expended shale is continuously withdrawn at 3. According to the invention, in one form thereof, there are provided peripherally disposed around the retort several points 8 for introduction of fines near the top of the bed. However, the 'feed must be distributed in a continuous stream around the retort.

In another embodiment shown in FIGURE 2 fines are introduced through peripherally located pipes 6 placed at several levels, these pipes 6 directly introduce fines along the inner wall of the vessel thus beneficiating the fines which are essentially annularly disposed between the vessel wall and the major portion of the bed. A screening, or grating, or grill 7 can be provided at least over a portion of the flow of the fines to assist when desired the ready or facile introduction of the fines material, the grill holding a substantial portion of the coarser materials away from the wall at least until the fines have been introduced, whereupon the bed of fines and the bed of coarse materials will move together with, at best, only some negligible amount of intermixing. In another form of the invention, some or all of the fines can be introduced between or at points substantially equidistant in this embodiment from air inlets or distributors 9, as at 10 the fines being passed downwardly through pipe 11. It will be understood that in a retorting operation as here exemplified, there can be several levels of air distributors. Still further according to the invention, some or all of the fines can be introduced by pipes, as pipe 12, to directly cover and to pass downwardly surrounding an air inlet as at 9.

According to the invention, retorting of oil shale fines below A" in size can be readily accomplished and there is secured a concurrent improvement in retort operation, the invention taking advantage as it were of the nonuniformity and temperature present in the bed, all low temperature areas extant or created, retorting the fines without clinkering and while protecting components of the vessel such as the wall or air inlet ducts, etc.

In lieu of the equipment shown, other equipment can be designed to carry out the various concepts of the method invention. For example, small slots within the vessel wall or within the pipe Walls can be used to blend in, as it were, the fines of the hydrocarbonaceous material. Whether the addition is being practiced to the edge of the bed and/or to the end of an area at or between distributors. By introducing the fines according to the invention around the air distributors, the air passes through the small size particles before meeting thus tending to spread out the burning zone. Additional fuel gas can be introduced either with or separately from the recycle gas.

The invention permits the retorting of all of the crushed particles except the very finest dusts in any large quantities.

The fines and the sizes thereof which can be fed in with coarser particles of the same or different materials can be determined by routine test. In the case of oil shale, the fines will usually be those that will pass through a A" mesh Tyler screen. The fines may contain some larger and some smaller particles, and, indeed, the sizes here given are intended to be understood to be average sizes. The proportion of the fines which can be fed according to the invention to any particular place in the apparatus can also be determined by routine tests for optimum results. The invention is further illustrated by the following example.

EXAMPLE A retort substantially square in axial cross section and approximately 30 feet high having four air distributors on 2 centers flowing shale at a rate of approximately 500 pounds per square foot, i.e., 50,000 pounds or 25 tons per hour is operated to yield approximately 625 gallons of hydrocarbon liquid per hour. Ten percent of shale fines that will pass through a A" mesh Tyler screen are introduced utilizing approximately A of the cross sectional area of the retort, i.e., about square feet. The perimeter of approximately 40' of the retort yields a thickness of approximately 3" of fines around the perimeter of the bed when all of the fines as in this example are fed to said perimeter. The conditions of operation in the retort, i.e., temperatures, air and any recycle gas fiow rates are substantially conventional but are adjusted for optimum results obtainable with the invention and will depend upon relative rates of flow of the coarse and fine materials as well as other factors.

Although in the example there is given a range of sizes for the fines, it should be understood that fines of much smaller sizes can be used. Obviously, the fines should not be so fine that they will be carried from the bed with the gases. Larger fines can also be used as long as there is a definite and controlled degree of segregation of the particles with the finer particles being in the locations stated.

One skilled in the art will recognize that various component parts of an overall operation for the beneficiation of a hydrocarbonaceous material according to the invention have been omitted for the sake of simplicity. Further, it will be understood that the overall retorting and recovery operation applied to vapors obtained is not a part of this invention and therefore has been omitted for sake of simplicity. It is within the scope of the invention to employ vapors obtained to carry the fines to the retorting operation, according to principles of solids carrying vapors.

Presently, it appears that of the order of at least 10 percent of mined materials such as oil shale, become fines, and their handling on a basis of separate facilities and complete discard is, of course, ordinarily prohibitive. The recovery of such fines, or a substantial amount of them, is a mere step supported in making available the content of solid hydrocarbonaceous materials by way of retorting operations. It is well known that there are oil shale deposits in Colorado and elsewhere which are very important indeed in size, but which are not readily commercialized. Further, present retort bed temperature profiles are inadequate for complete oil recovery. Here, too, the invention can be used to improve the recovery.

While the invention has been described as it is particularly applied to oil shale, it can be applied to other substances such as a low quality coal.

Reasonable variation and modification are possible within the scope of the foregoing disclosure, the drawing and the appended claims to the invention, the essence of which is that there has been provided a method for the beneficiation of hydrocarbonaceous fines in a retorting operation in which coarser hydrocarbonaceous material, which can be the same or different from that of the fines, is also being retorted -by feeding said fines to at least one of several preselected places or sections within the retort,

for example, to the wall and/or to a place within the bed removed from the air or fuel distributors, or to a place surrounding at least one of such distributors.

I claim:

1. A method for retorting hydrocarbonaceous fines-containing material which comprises passing said material into a retort, in which coarser material is moved downwardly as a compact moving bed and is being retorted, to a preselected section in said retort at which conditions optimum for retorting of said fines exist and at which said fines will be subjected to said optimum conditions for their beneficiation, due to the conditions of operation there existing and their presence in said retort in said moving bed at said place and later in said moving bed as it moves in the retort, the fines being introduced into and through a downcomer extending into said compact bed of coarse shale so that the fines are introduced below the top level of said bed and moved downwardly together therewith.

2. A method according to claim 1 wherein at least a portion of the fines is fed to [at least one place in the periphery of a bed of the material undergoing retorting.

3. A method according to claim 1 wherein at least a portion of the fines is fed to a point in a bed of the material undergoing retorting, but at a place removed from one of an air and fuel inlet to said bed.

4. A method according to claim 1 wherein at least a portion of said fines is introduced to surround at least one of an air and vapor inlet.

5. A method according to claim 1 for retorting a hydrocarbonaceous material which comprises crushing the same, separating a fines-containing portion from the crushed material, passing the crushed material into a retort, separately introducing the fines material to a preselected portion of the retort where the fines can be advantageously beneficiated and retorting said fines together with the remainder of material in said retort.

6. A method according to claim 1 wherein the hydrocarbonaceous material is oil shale.

7. A method according to claim '5 wherein said hydrocarbonaceous material is oil shale.

References Cited UNITED STATES PATENTS 2,026,923 1/1936 Warner 20134 XR 3,384,557 5/ 1968 Saller 2019 XR FOREIGN PATENTS 668,808 3/ 1952 Great Britain.

NORMAN YUDKOFF, Primary Examiner D. EDWARDS, Assistant Examiner US. Cl. X.R. 20129, 32

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