US3409509A

US3409509A - Shale retorting apparatus

Info

Publication number: US3409509A
Application number: US400993A
Authority: US
Inventors: George D Gould
Original assignee: Chevron Research and Technology Co
Current assignee: Chevron USA Inc
Priority date: 1964-10-02
Filing date: 1964-10-02
Publication date: 1968-11-05
Anticipated expiration: 1985-11-05

Description

United St ws aten ABSTRAC.T OF THE-DISCLOSURE Shale r'et'orting Pparatus comprising vertically: elongated housing for" downwardly movinglshale, elongated oxygen supply conduits within said housing extending downwardlyfrom-an upperportion of said housing and terminatin' in lower free: ends below about the midpoint organ housing", said lower. freejends being the gas, release epgls' p 7 lower free ends means fordefiecting downwardlymoving shale from the immediate gas release areas near said lower free ends, said conduits havingsufficient flexibility to permit said lower free ends to move with respect to each other in response to forces exerted by downwardly moving shale.

of saidconduits, said-conduits having at said 1 2 gas and the recycledg as" is burned in thecoii1b us 'nizorie in the presence of further quantities of ogrygen-dontainihg' as. p (f Heretofore, 'whenthe combustion zone in the downwardly moving column ofparticulate solids ns comprised a plurality "of'small solids-free burners, thesefburners' w have been relatively fix ed' with respect to "each other" and retorting oil shale and bituminous solids of similar 'character in order to recover valuable liquidand gaseous hydrocarbon products; and particularly to anapparatus whereindownwardly moving solids are counterc'urrently contacted with a gaseous medium for supplying said solids with retortingheat; and an object of the invention is to-provide-improvedmeans for developing the necessary retorting heat carried by'said gaseous medium and"su'p-* plied by said gaseous medium to saidsolid:

, In=itsfundamental "aspects, 'the'retorting or "destructive distillation of oil shale'andother solid hydrocarbonaceous materials is a relatively simple'operation; Basicallyit involves only the steps of heating the solid material to the proper temperature and of recovering the liquid products evolved. However, in the development of apparatus for carrying out this fundamentally simple operation it has become apparent that defective operation and process failure can result fro'rn failureof the apparatus to perform itsin'tended function in any' one of a number of ways. The present inventionisconcerned withovercoming one type of failure of one type of retorting apparatus ,toperform its intended function. I: e

The retorting apparatus with which the present invention is concerned is well known in the art, and has been described in US. Patent 2,757,129 and references cited therein, and in US. Patent 2,899,365 and references cited therein. More particularly, the type of apparatus with which the present invention is concerned comprises an elongated housing for a continuous downwardly moving column of retortable solids in particulate form, a gas combustion zone or zones being located within the downwardly moving column of solids, said gas combustion zone being designed to provide a solids-free zone wherein combustible gases may be burned in the presence of an oxygen-containing gas, said combustion zone further being so located in the downwardly moving column of solids that hot gases rising from the combustion zone distill kerogenic materials from the solids in the column immediately above the combustion zone, heat from the rising distilled products is transferred to incoming solids, the distilled products are removed from an upper portion of the housing, a liquid product is recovered from the distilled products, a combustible gas from the distilled products is recycled in a lower portion of the housing below the combustion zone, heat is transferred from the hot spent solids below the combustion zone to the recycled have been'su'pplied with'ari oxygen-containing gas-through conduits entering the sides 'of the retort housing iieargthe b'iir'ners, as in FIGURE 1 ofUSfPaten't 2,757,129.,It has been found that "when the downwardly moving par; ti'culate solids contained fmater ialsfthat have inot be'eri crushed to"'a' suitably small sizejlo'r when a plurality of particles of downwardly movingmaterial's' 'becgme ce-i merited together.by 'coke from' feflux ing' l ilydroca'rbo or' otherwise fused together,"beforeieacliing tliebu r area, they can become jammed between the indiv dual burners, causing all or a'po'rtiono'f the downwardly moving column of solids to stop moving and to back up'in the retort housing, thereby necessitating costly shutdown in order to remedy the trouble. Defective operation caused by this type of trouble is avoided by use of the apparatus of the present invention. a

In accordance with the present invention there is prof vided apparatus for the destructive distillation of solid hydrocarbonaceous materials comprising a ver tically elon gated housing for a downwardly moving continuous ver tical column of said solid materials, means for introducing said solid materials in fresh condition at an upper por-f tion of said housing, means for withdrawing said solid materials in spent condition from a lower portionof said housing, means for introducing an oxygen-containing gas into an intermediate portionof said housing'comprising elongated conduits within said housing extendingldtrwmwardly from an upper portion of said housing andte'rminating in lower free ends below about the'midpoint of said housing, ends of said conduits, said conduits havingtat said lowei free ends means for deflecting downwardly moving solids from the immediate gas release areas near, said lower free ends, said elongated conduits having sufficient flexibility to permit said lower free ends to move with respecttoteach other when downwardly moving solid materials exert, lateral forces at said lower free ends, said apparatus fur; ther comprising means at' a lower portion of said housing for introducing combustible gases into said housing, and means at an upper portion of said housing for removing oil vapors from said housing. i T The novel features of'the present invention are set forth with particularity in the appended claims. The invention will best be understood however, both as to organization and operation, and additional objects thereof will be apparent from the following description of a specific embodiment thereof when read in connection with the accompanying drawing. In the following description shale retorting specifically is discussed, although it will be understood that the description also applies to other retortable solids. In the description it is considered unnecessary to discuss shale particle sizes, flow rates, gas rates, retorting temperatures, and other technical aspects of shale retorting which by now are well known to those skilled in the art and which are adequately disclosed in prior art patents.

The accompanying drawing is a diagrammatic illustration of an embodiment of apparatus and flow paths for retorting shale in the presence of hot gases, in which noncondensable gases recovered from the shale, together with recycle combustion gases, are preheated by contacting them with hot spent shale in a gas preheating and solids cooling zone, in which at least a portion of said preheated gases is burned in the shale column but out of immediate contact with the shale. in which heat, including heat from said gas burning, is carried upwardly by rising gases to a said lower free ends being the gas release,

retorting or distillation zone in the shale column and in which kerogenic materials distilled from the shale in the retorting zone are cooled in a solids preheating and products cooling zone and are then withdrawn from the retort housing.

Referring now to FIGURE 1, fresh crushed shale is introduced through line 1 and gas tight valve 2 into solids preheating and cooling zone 3 of retort housing 4 where it is heated by rising hot Vaporous retort products and combustion gases. The thus preheated shale passes downwardly through retorting or distillation zone 5 wherein kerogenic constituents thereof are distilled therefrom under the influence of heat carried by hot gases rising from combustion zone 6. After passing from retorting zone 5 through combustion zone 6 the hot spent shale passesthrough gas preheating and solids cooling zone 7 in which heat is transferred therefrom to cool recycle gases entering housing 4 through line 8. The cooled spent shale is removed from housing 4 through line 10 and gas tight valve 9.

- Vaporous retort products and combustion gases are removed from housing 4 through line and are passed into gas liquid separator 16 from which a liquid product is recovered through line 17. Combustible gases are recycled from gas liquid separator 16 through line 8. If desired, a gaseous product may be removed from the system through line 18. Also if desired, a combustible gas from an external source may be introduced into the system through line 19 to augment the combustible gases being produced in the system.

The combustible gases entering housing 4 through line 8 are heated as they rise through gas preheating zone 7 by countercurrent contact with downwardly moving hot solids in zone 7. The thus preheated gases combine in burning zones 20 located at the ends of flexible conduits 21 with oxygen-containing gas entering burning zones 20 through conduits 21 and are thus burned in burning zones 20 out of immediate contact with the downwardly moving column of shale. The hot combustion product gases from burning zone 20 rise in countercurrent contact with the downwardly moving column of shale, causing retorting of the shale in retorting zone 5, as previously discussed.

Should the particle size of the raw shale entering housing 4 through line 1 be larger than in normal operation will freely flow between combustion zones 20, or should the downwardly moving shale particles become agglomerated or fused together before they reach combustion zones 20 to an extent that will impede their normal free passage between combustion zones 20, the flexibility of conduits 21 permits combustion zones 20 to move apart with respect to each other under the influence of the lateral forces caused by the oversized shale particles or agglomerates passing between combustion zones 20. Accordingly, an apparatus is provided that is free from the conventional problem of jamming of downwardly moving shale particles in a rigidly fixed system of grates forming a portion of the gas combustion zone in the shale column.

It is understood that many modifications in the present apparatus could be made without departing from the basic features of the invention; for example, a reversal of parts asby having the conduits 21 extend from the lower portion of housing '4 rather than from the upper portion is possible. All such modifications which can be made without departing from the spirit and scope of the invention are intended to be covered hereby, and the only limitations in the present invention intended herein are those indicated in the appended claim.

I claim:

1. Apparatus for-the destructive distillation of solid hydrocarbonaceous materials comprising a vertically. elongated housing for a downwardly moving continuous vertical column of said solid materials, means for introducing said solid materials in fresh condition at an upper portion of said housing, means for withdrawing said solid materials in spent condition from a lower portion of said housing, means for introducing an oxygen-containing gas into an intermediate portion of said housing comprising elongated conduits within said housing extending downwardly from an upper portion of said housing and terminating in lower free ends below about the midpoint of said housing, said lower free ends being the gas release ends of said conduits, said conduits having at said lower free ends means for deflecting downwardly moving solids from the immediate gas release areas near said lower free ends, said elongated conduits having sufiicient flexibility to permit said lower free ends to move with respect to each other when downwardly moving solid materials exert lateral forces at said lower free ends, said apparatus further comprising means at a lower portion of said housing for introducing combustible gases into said housing, and means at an upper portion of said housing for removing oil vapors from said housing.

References Cited UNITED STATES PATENTS 2,757,129 7/1956 Reeves et a1. 20l2'7 2,901,402 8/1959 Putman 20l29 XR 3,318,798 5/1967 Kondis et a1 20l29 XR NORMAN YUDKOFF, Primary Examiner.

D. EDWARDS, Assistant Exdminer.