US2544843A - Treatment of solid hydrocarbonaceous material - Google Patents

Description

March 13, 1951 F. A. w. Ll-:FFER 2,544,843

TREATMENT oF soun ETnRocARBoNAcEoUs MATERIAL Filed Jan. 28, 1948 tively compact mass.

3 conjunction with the remaining features of the operation according to the invention. The overall heat economy of the operation is not only furthered by handling of the solid material in the nely divided state, but also by substantially complete avoidance of loss of sensible heat between the three principal stages of the process.

The attached drawing illustrates diagrammatically a suitable arrangement of an apparatus in which the process of my invention may be effected.

Finely divided oil shale or the like is supplied from a hopper I through line 2 and valve 3 to an elevated portion of distillng retort 4, preferably to a point below the upper level of the solid material therein. The ilow of the solid from the hopper may be aided by aerating the solid material by means of a suitable gas supplied through line and valve 6.

In retort 4, the solid is submitted to the distilling and stripping action of highly heated gases and/or steam generated within the process, preferably in the absence of air or oxygen; the steam is supplied from heating zone I (which is also a retort) through line 8 and valve 9 to one or more points at the lower portion of retort 4 and passes upwardly through the solid material moving downwardly through the retort either in a relatively compact mass or a fluidized dense phase.

Upon reaching the bottom of retort 4, the solid material is substantially devoid of any volatilizable hydrocarbons and is permitted to flow through line I and valve I2 into transfer line I3 wherethrough it is moved with the aid of a gaseous medium to the combustion retort I4, to be introduced to the latter at an elevated point thereof. In the arrangement shown, the solid transferred through line I3 is passed through separator I5 wherein it is separated from the gaseous medium whereupon it moves downwardly under the force of gravity through line I6 into combustion retort I4, wherein substantially all of the combustible content of the uid particles is burned off. To elect the combustion, air is introduced into the lower portion of retort I4 through one or more burner ports I1, I'I, or the like; these ports are designed to permit operation of the retort i4 under any desired pressure and may also serve for the introduction of an auxiliary fuel during the starting up of the operation or whenever auxiliary fuel may be desired for more eiectively operating the process. The solid particles are preferably permitted to pass downwardly through retort I4 in a relatively compact mass, although the solid may be maintained in retort I4, in a iluidized dense mass, if this is .desirable and the particle size of the solid material is such that a nuidized dense phase will be obtained with the aid of such an amount of air as is required for substantially complete combustion of the combustible content of the solid.

The burned solid residue flows from the bottom of combustion retort i4 through line I8 and valve I9, into heater 1, and is permitted to move downwardly therethrough, preferably in a rela- During its downward passage, the highly heated solid is brought in contact with low temperature steam or with water, either of which may be introduced to the bottom portion of heater 'I at one or more points thereof as through line and valve 2l, and thereby a substantial or major portion of its heat content is transferred to the water or steam, where- 4 by highly heated or superheated steam is generated. This steam is discharged from heater 'I vthrough line 8, and supplied at least in part as already described, through Valve 9 to distilling retort 4. Any portion of the steam not required for eecting or aiding in the retorting of the oil shale may be withdrawn through line 22 and valve 23 for use elsewhere.

Any gaseous medium may be used for transferring the retorted solid particles from line Ill to combustion retort I4, but the heat economy of the process will be kept at an optimum degree of efliciency, and substantial loss of heat from the retorted solid will be avoided by use of the spent combustion gases issuing from the combustion retort I4 through line 24. These hot combustion gases may be forced into line I3 by means of blower 25, which discharges through lines 26 and 2I and valve 28 into line I 3 at the junction of the latter with line l0.

The heat economy of the process will be further improved by precluding any substantial loss of heat from the highly heated non-combustible solid particles during their passage from combustion retort I4 to heater 7. It is to be understood that all lines carrying hot streams of the aforesaid nature, as well as retorts 4 and I4 and heater I should be insulated suciently to lpreclude substantial loss of heat by radiation. Insulation of retorts 4 and I4, and if desired, also of heater 'I, may be applied internally whereby erosion and corrosion of the metallic vessel walls will be prevented or at least reduced to a minimum.

While not essential to the successful operation of the process, it may sometimes be desirable to supply a portion of the spent or oxygen-free combustion gases from line 26 through valve 29 into line S and therethrough into distilling retort 4. This supply of hot inert gases in addition to the supply of more highly heated steam may, for example, aid in the maintenance of a `dense phase in retort 4, when the nely divided solid is sup- 'plied thereto in a relatively coarse particle size requiring a relatively large quantity of gaseous medium for the maintenance of a thoroughly agitated dense phase in retort 4.

While line 3 has been shown to discharge into separator I5, it may, if so desired, terminate at an elevated point of combustion retort I4, preferably so as to discharge the distilled solid particles into said retort I4 at a point below the upper level of the solid mass or fluidized dense phase therein. In this event, spent combustion gases not required for transfer of the solid through line I3 may be removed from the top of retort I4 through a line not shown, and through separator I5, to be discharged through line 33 and valve 3| to any suitable equipment for recovering heat from this gas stream.

Without departing from the general idea of countercurrent extraction treatment of oil shale and the like with utilization of the combustible materials in the distillation-extraction residue for furnishing heat for the process without use of any tubular or other conventional steam generators, the process may be modied by efecting the transfer of the solidresidual material from distilling retort 4 to combustion retort I4, by means of a suitable mechanical conveying device. Similarly, without departing from the general concept of the process, the arrangement of apparatus may be modified by superimposing distilling retort 4 on combustion retort I4, and permitting the residual solid particles from the former to flow into the latter by gravity, substantially as described with reference to `lthe flow through line I8 and valve I9. In such a modification, the highly heated solid residue from combustion retort I4 `may be transferred to heater I by mechanical means if said heater Vis disposed substantially parallel to and at about the Same level as, instead of Vcoaxially with and below, retort I4. The arrangement shown in the drawing is, however, preferable for most purposes. Alternatively, if s o desired, the distilling retort 4 may be superimposed on the combustion retort and the distillation residue permitted to flow by gravity through line I and valve I2 directly into the upper portion of the combustion retort, while still retaining the arrangement of the combustion retort superimposed on the heater and causing the combustion residue to f low by gravity into the heater. This particular arrangement entirely dispenses with moving mechanical parts coming into contact with hot materials. But even when employing the arrangement as shown in the drawing, only a blower (25) for moving gases at hightemperature will be required; and this does not entail the wear and tear and the operating difficulties encountered with moving parts exposed to high temperature during their employment for handling solids.

It is to be understood that aeration by a suitable gas such as superheated steam taken from line 22 through valve 23 may be resorted to for the purpose of decreasing the density and assisting the iiow of the material flowing through line I0 and/or line I8 in any one of the embodiments described.

It is also to be understood that any suitable means may be employed for simultaneously assuring undisturbed withdrawal of the respective finely divided solid materials from retorts 4, 'I, and I4 and substantially uniform distribution of the normally iuid media upon their introduction to these retorts. For example, when operating with the iinely divided solid material in any one of the retorts in a fluidized relatively dense phase, a horizontal perforated plate may be disposed in the lower part of the retort and a gaseous fluid may be supplied thereto below the plate and distributed through the perforations into the fluidized dense phase above the plate while a stream of solid particles of the material undergoing treatment is withdrawn from the dense phase in the retort and from the retort itself through a standpipe terminating at a point somewhat above the perforated plate as diagrammatically indicated in the drawing by broken lines with reference to the lower part of retort 4. Alternatively, when treating the finely divided solid material in any one ofv the retorts 4, and I4 while said material passes downwardly therethrough in a relatively compact mass or bed, the normally fluid medium to be contacted with the finely divided solid material may be introduced in an upward direction to the latter through a perforated distributing member, such as is diagrammatically illustrated in the drawing by broken lines with reference tothe lower part of retort 'I and which allows a free passageway for the descending solid partices to the withdrawal.,

conduit provided at the bottom of the retort. Another suitable means for this purpose consists ofan inverted perforated cone disposed above the bottom ofthe retort, gaseous fluid being supplied to the interspaee between the perforated cone and the retort bottom and'` finely-divided solid material being withdrawn from above then- 6 ver-ted leone downwardly through a standpipe terminating in the apex of the-cone.

The vaporous distillation products liberated in dis-til'ling retort 4, are removed therefrom through line 32- teHsepar-ator 33, wherein they are substantially freedv from solid particles, the latter being returned to retort 4 by line 34, which penetrates to below the levelof the relatively compact mass of iluidized dense phase within retort 4. The vaporous distillation products are thereupon conducted from separator 33 through line 35 and valve 36 to suitable fractionation and condensing equipment for recovery of normally liquid and normally gaseous product fractions and for their separation from aqueous fluids comprising the water resultingy from the condensation of the steam introduced to retort 4. The fractionating and separating equipment may be of conventional design and may be supplemented by chemicalA treating sections for removing acidic components from the hydrocarbon fractions produced by theY distillation of the oil shale or the like hydrocarbonaceous materials.

In the processasdescribed., the countercurrent flow of gaseous heating 'medium and finely divided solid in retort 4 materially benefits the ultimateV yields of the valuable hydrocarbon oil fractions desired as primary product of the process and reduces to a minimum, undersirable cracking reactions which would result in excessive gas formation. Destructive distillation or cracking occurs to the desiredextent in the lower or hotter portion of the distilling retort While primarily a non-destructivey distillation takes place in the upper or relatively-cool portion of this retort. Any portion of the gases formed duringthe distillation, particularly a relatively 'light portion thereof comprising principally terial'to furnish the heatv requirements of the process. Y While the countercurrent flow treatment" has been included above as a benecial feature of the'r preferred'embodiment of the process, it will be evident from` the foregoing that thev invention is not necessarily limited thereto and that it is an important characteristicof' the invention in itsbroader aspects to effect the treatment of finely divided oil shale and like-bituminous solids ofrelatively high non-combustible content duringy a continuous flow through three successive stagesl comprising distillingn the finely divided solid bycontact in a distilling Zone with a highly heated gaseous heat-carryingl medium compris'- ing Superheatedl steam producedv within-the process, supplying the hot finely divided distillation residue toa combustionA zone and' thereinY burning substan-tiallyl allundistilledfcombustibl'e materials from said distillation residue whereby to impart' an increased heaty content, to the noncombusti-blev residue, supplying thev hot finely dividedsolid residue from the'combustion. zone substantially without: intentional loss` of heat to alleati-ng zone andtherein abstracting heat from said solid residue and producing super-heated steam-by contact of said residuefwith -anaqueous riiuiolsuchJ as water or low temperature. steam,

discharging the finely divi-dedV solid' residue from the heating zone atr a substantially lowered temperature, amr supplying atleast a: portion. of

7 the superheated steam as highly heated-heatcarrying medium to the distilling zone.

In carrying out the process the temperature distribution in the distilling zone or retort Will depend largely on the initial composition of the solid charge and in any event is to be sufficient to carbonize tarry components of the solid particles so as to permit the distillation residue to f remain in iinely divided state for its transfer to the combustion zone or retort. The process may be operated under any suitable pressure and normally will be carried out at about atmospheric or a moderate superatmospheric pressure up to about atmospheres, although it may in some cases be desired to operate under higher pressure so as to permit relatively smaller dimensioning of the apparatus for a. given throughput of materials and also to permit obtaining steam under relatively high pressure. A further advantage in using relatively high pressure residues in the avoidance of mechanical conveying equipment for discharging the cooled solid residue from the heating retort or heater l. In general the pressure in the three principal zones of treatment Will be approximately equalized except for such differential pressures as are necessary to assure adequate iiow of superheated steam from the heater to the distilling retort.

In the normal operation of the process, Water is preferred to low temperature steam for supply through line 2n to heater 1. This procedure will not only permit a maximum recovery of the heat content from the non-combustible residue charged to the heater, but by the use of Water in excess of the quantity required for steam generation the cooled solid residue may be formed into a slurry and so removed from the bottom portion of heater 1 through line 3l and valve 3B. Water is thus used as a conveying medium for carrying the solid residue to a point of disposal or utilization outside the system. In this latter mode of operation a portion of the water used for the slurrying may be recovered by settling, and returned to the heaterv to reduce the overall supply of water requirement of the process from an outside source.

The selection oi iineness of the particles charged to the distilling zone is dependent'to a large extent on economic considerations. Greater amounts of energy would be required for grinding to extreme neness, such as 200 mesh or ner in the U. S. sieve series or about 0.075 mm. or less in diameter, While a coarse particle size, such as 3 mesh or larger in the U. S. sieve series or about 7 mm. or more in diameter, would render more diiiicult the transfer of the solid materials from the distillation zone to the combustion zone, and from the latter to the heating zone as Well as the discharge of the incombustible residue from the heating zone to a suitable point of disposal. It is therefore preferred to opera the process in many instances with a medium particle size of less than 5 mm. diameter, the size being such that al relatively compact bed rather than a highly iluidized dense phase prevails in the distilling zone, yet the non-combustible residue will be of suilicient fineness to permit slurrying out of the heating zone by means of Water. A particle size of from approximately 0.1 to about 3.0 mm. diameter is preferred for compact bed operations, while a particle size Within the approximate range of 0.1 to 0.8 mm. diameter is preferred for fluidized dense phase operations.

In conventional oil shale distillation operations of the prior industrial art Where the carbonized residue is utilized for generation of heat for the process, the carbonized residue is iirst quenched so as to permit handling in the open air and this quenching .constitutes a substantial heat loss. In the present operation the carbonized residue is transferred directly, and while still hot to the combustion retort which as already described above may be accomplished advantageously by means of the hot combustion gases obtained from the combustion retort so that an unduly elevated arrangement of the apparatus sections may be avoided. The overall heat economy of the process is further enhanced by avoidance of indirect heat exchange in the principal processing steps, and preferably by effecting the direct heat exchange in each of the three principal process steps by -countercurrent flow.

In the operation of my process, the spent combustion gases from the combustion retort are supplied to heat recovery. In the Working up of recovery of the distillation products in a Suitable recovery plant, a substantial amount of heat is required and according to my invention l contemplate the utilization for this purpose of the heat present in the spent combustion gases. A portion of the hot spent combustion gases may, moreover. be employed for drying oil shale or like material prior to supplying such material to distilling retort 4. Such drying may be effected after comminution of the solid charge, if so desired, and in any event, should be carried out in a manner assuring the maintenance of the solid material at temperatures below about 200 C. l

The principal source of heat in the distilling retort is the highly heated gaseous heat-supplying medium supplied thereto from heater 'l of the system. In an operation in the manner herein described, the -countercurrent flow assures a minimum of cracking which will be less when a relatively compact bed of the iinely divided solid is caused to flow downward, relative to an operation wherein a highly agitated fluidized bed is employed in the distilling retort. In the relatively compact, downwardly moving bed, a temperature gradient results with a maximum temperaturein the lowest, and a minimum temperature in the highest portion of the distilling retort, so that volatile products liberated at a relatively hot point of the retort will immediately pass to a zone of lower temperature while at the same time they are diluted with more reiractory volatilized components which are liberated in the upper or cooler portions of the distilling retort, and with steam which aids in avoiding or minimizing cracking reactions. The use of steam as substantially the sole, or at least, the principal direct heat supplying mediurn in the distilling retort, also has the advantage of enabling one to separate the steam from the organic products insoluble in water by layer separation upon its condensation in the recovery plant, and thus to avoid a dilution of the distillation products which would make diiiicult the recovery of the latter.

While it is herein indicated that it may sometimes be desirable to supply a portion of the spent or oxygen-free combustion gases from the combustion retort through the valve 2S to the distilling retort, it will be understood from the foregoing that the preferred operation does not resort to this auxiliary supply of combustion gases to distilling retort 5., and will operate solely with the supply of the high temperature steam thereto.

In accomplishing the desired distillation in the distilling retort, the temperature and quantity of the steam will primarily depend on the nature and quantity of the solidY charge, and particularly on the content of the volatilizable organic compounds in the solid charge. As a rule, a steam temperature of less than 650 C., and more particularly of from 500 to 600 C. will be ample to eiect the distillation of most kinds of oil shale and torbanite at a suitable weight ratio of solid treated to steam contacted therewith. Generally the maximum temperature of the solid material in the distilling retort need not exceed 500 to 525 C., and the temperature gradient may extend downwardly to about 300 C. but will depend largely on the relative rates of throughput of solid material and steam, and in the normal operation, the minimum temperature of the vaporous and gaseous products issuing from the upper portion of retort 4 through line S2, will be in the neighborhood of 400 to 450 C. This relatively high temperature is desirable for a maximum recovery of hydrocarbon oils but may be kept lower when it is preferred to sacrifice total yield of oil in order to obtain a relatively high yield of lower boiling hydrocarbon oil fractions- In the latter case the highest boiling volatilizable components of the oil shale or other bituminous solid will be retained in the distilling retort and will eventually be cracked into lower boiling components and carbonaceous or non-volatilizable residue.

In eecting the combustion of the undistilled combustible components retained in the distillation residue owingfrom distilling retort 4 to combustion retort lf3, a controlling factor of operativeness is the sintering point of the ash constituents in the distillation residue. In general,

`sintering will be avoided as long as the temperature of the solid particles does not exceed about '700 C. Combustion in the combustion retort can readily be accomplished effectively while the solid particles are at temperatures between about 600 and 650 C., as the combustion is rendered uniform and substantially free from hot spots because of the comminution and mobility of the solid particles in the present process. With some Voil shales, sintering will not occur until temperatures of 800 C. or more are reached, and with materials of this nature, relatively high temperatures of the order of '200 to 750 C. may be employed safely for the solid particles in the combustion retort. Air for combustion may be supplied, if so desired, at a plurality of superimposed regions in retort Il-l so as to preclude localized overheating. In general. only suiicient air should be supplied to the combustion retort to eiTect substantially complete combustion ofthe combustible components and to obtaina substantially oxygenfree gas, the completeness of combustion being aided by the counterourrent flow of combustion gases and the nely divided solid which enters the combustion retort already at a temperature sufficient to support combustion. The best operation from the point of heat economy comprises the maintenance of a combustion temperature just sufciently below the sinteri'ng temperature of the incombustible residue to retain the latter in a freely flowing state whereby it will be possible to obtain a maximum steam temperature in heater 1 upon supplying the highly heated incombustible residue from combustion retort I4 to heater l. Likewise, the best operation from the point of yview of heat economy will comprise maximum utilization of the heat `content of the hot incoml0 bustible residue by cooling it in heater 1 sufciently to permit its discharge from the bottom of the latter at a temperature below about C.

The process of my invention may be carried out under any desired pressure. Only relatively small pressure differences are required between the 3 principal processing stagesl in order to maintain the ilow of solids therethrough. While relatively low pressure is preferable for maximum recovery of normally liquid hydrocarbons, it may be .preferable from the point of view of overall efficiency to maintain in the system a pressure of the order of 10 to 15 atmospheres in order to have excess steam under substantial. superatmospheric pressure available for use in the recovery plant and in order to use the spent combustion gases issuing from the vcombustion retort under the aforesaid pressure of about 10 to 15 atmospheres for the generation of power for use in handling the raw oil shale or like bituminous solid while preparing it for feeding to the system. It is evident that relatively little power is required for feeding the nely divided solid material under pressure to retort ll, and water under pressure to heater 1, so that a substantial benefit will be obtainable when generating the spent combustion gases under pressure and then utilzing a portion of theV energy stored therein for power generation by means of turbines or the like.

In an alternative operation of my process, normally gaseous hydrocarbons, more particularly relatively refractory hydrocarbon-containing gases such as natural gas or light fractions thereof comprising methane and ethane, are supplied through line 20 to heater 'I in which heat is transferred from the non-combustible solid residue of the shale to said gaseous hydrocarbons and the resultantheated gaseous hydrocarbons are directed through line 8 to. distilling retort 4. In the preferred embodiment of this operation, hydrocarbon gas fractions produced within the process and separated from the products discharged from distilling retort 4 through li-ne 35, and particularly the methane and ethane fractions thereof, are employed as the gaseous hydrocarbons supplied through line 20 to heater 1.

I claim as my invention:

1. A process for the treatment of solid hydrocarbonaceous material which comprises continuously supplying a stream of nely divided solid hydrocarbonaceous material of relatively .high ash content to a conned distilling zone and passing it in a dense mass downwardly through said zone in direct contact with a gasiform heatsupplying medium comprising superheated steam at distilling temperature, withdrawing a stream of hot finely divided distillation residue from said distilling zone and commingling the same with a hot gaseous fluidizing medium, transferring said residue stream uidized in said gaseous fluidizing medium and substantially without intentional `cooling to a separate conn-ned combustion zone and therein burning substantially all undistilled combustiblematerial from said distillation residue while conducting the latter in a densemass downwardly in direct contact with a free oxygencontaining gas, introducing said superheated steam to the lower portion of said distilling zone and said oxygen-containing gas to the lower portion of said combustion zone each at a ratey at which the solid material in the dense masswithin each of said zones is maintained in nely subdivided and freely flowing state, withdrawing a vaporous stream. of distillation products and gasiform heat-supplying medi-umfrom the upper porktion of said distilling zone while independently thereof discharging hot combustion gases from the upper portion of said separate combustion zone, passing a stream of highly heated noncombustible residue from said combustion zone substantially without intentional cooling to a separate and confined heating zone and therein cooling said non-combustible residue by direct contact with water in an amount in excess of that required to generate said superheated steam, continuously feeding a stream of the resultant superheated steam from said heating zone directly to said distilling zone, and discharging a slurry of iinely divided solid residue and water at a substantially lowered temperature from said heating zone.

2. A process for the treatment of oil shale which comprises continuously supplying a stream of oil shale divided into particles of less than mm. diameter and predominantly less than 3 mm. diameter to al confined distilling zone and passing it in a relatively dense mass downwardly through said zone in direct contact with a gasiform heat-supplying medium comprising superheated steam at a sufficient temperature and in su'icient quantity to vaporize and expel substantially all distillable components from said oil shale, withdrawing a stream of hot finely divided distillation residue from said distilling zone and commingling the same with a hot gaseous fluidiz- 1 ing medium, transferring said residue stream fluidized in said gaseous fluidizing medium and substantiallyT without intentional cooling to a separate and confined combustion zone and therein burning substantially all undistilled combustible material from said distillation residue while conducting the latter in a relatively dense mass downwardly in direct contact with a free-oxygencontaining gas, introducing said superheated steam to the lower portion of said distilling zone and said oxygen-containing gas to the lower portion of said combustion zone each at a rate at which the solid material in the dense mass within each of said zones is maintained in finely subdivided and freely flowing state, withdrawing a vaporous stream of distillation products and gasiform heat-supplying medium from the upper portion of said distilling zone while independently thereof discharging hot combustion gases from the upper portion of said separate combustion r zone, passing a stream of highly heated non-combustible residue from said combustion zone substantially without intentional cooling to a separate and coniined heating zone and therein cooling said non-combustible residue by direct contact with water in an amount in excess of that required to generate said superheated steam, continuously feeding a stream of the resulting superheated steam to said distilling zone, with the temperature of said steam being substantially above the maximum temperature prevailing in the distilling zone, and discharging finely divided solid residue at a substantially lowered temperature in a slurry with said excess water from the lower portion of said heating zone.

3. A process for the distillation of subdivided solid hydrocarbonaceous material which comprises continuously supplying a stream of said subdivided material to a conned distillation zone and contacting it oountercurrently with a gasiform heat-supplying medium to distil volatilizable hydrocarbons therefrom, transporting the resultant finely divided solid distillation residue from said distillation zone to a separate confined combustion zone by means of hot combustion gases, obtained as hereinafter set forth, supplying a gas containing free oxygen to said combustion zone and therein burning substantially all undistilled combustible material from said residue while conducting the latter downwardly countercurrently to the oxygen-containing gas, withdrawing a vaporous stream of distillation products and heat-supplying medium from said distillation zone, withdrawing hot combustion gases from said combustion zone and supplying at least a portion of said hot combustion gases as the medium for transporting said distillation residue from the distillation zone to said combustion zone, introducing said gasiform medium to said distillation zone and the oxygen-containing gas to said combustion zone each at a rate at which the subdivided solid material in the descending mass within each of said zones is maintained in a finely divided and freely flowing state, passing a stream of highly heated non-combustible residue from said combustion zone substantially without intentional cooling to a separate and confined heating zone and therein cooling said non-combustible residue by direct contact with a uid heat-carrying medium substantially devoid of free oxygen, continuously feeding a stream of resulting highly heated gasiform heatcarrying medium from said heating zone as said heat-supplying medium directly to said distilling zone, and discharging a stream of finely divided solid residue at a substantially lowered temperature from said heating zone.

4. A process for the distillation of finely subdivided solid hydrocarbonaceous material which comprises continuously supplying a stream of said nely subdivided material to a confined distillation zone and contacting it countercurrently with a gasiform heat-supplying medium to distil volatilizable hydrocarbons therefrom, transporting the resultant finely divided solid distillation residue in a iuidized stream from said distillation zone to a separate conned combustion zone by means of hot combustion gases, obtained as hereinafter set forth, supplying a gas containing free oxygen to said combustion zone and therein burning substantially all undistilled combustible Vmaterial from said residue while conducting the latter downwardly countercurrently to the oxygen-containing gas, withdrawing a vaporous stream of distillation products and heat-supplying medium from said distillation zone, withdrawing hot combustion gases from said combustion zone and supplying at least a portion of said hot combustion gases as the uidizing medium for transporting said distillation residue from said distillation zone to said combustion zone, introducing said gasiform medium to said distillation zone and the oxygen-containing gas to said combustion zone each at a rate at which the subdivided solid material in the descending mass within each of said zones is maintained in a hindered settling and freely flowing state, passing a stream of highly heated non-combustible residue from said combustion zone substantially without intentional cooling to a separate and conned heating zone and therein cooling said non-combustible residue by direct contact with Y an aqueous uid, continuously feeding a stream of resulting superheated steam as the sole heatsupplying medium from said heating zone directly to said distilling zone, with the temperature of said steam being substantially above the maximum temperature prevailing in the distilling Zone, and discharging a stream of finely divided solid residue at a substantially lowered temperature from said heating `zone.

5. A process for the distillation of subdivided oil shale which Ycomp-rises continuously supplying a stream of said subdivided shale particles of not more than about 0.8 mm. diameter to a confined distillation zone and contacting it counter-currently with a gasi-forin heat-supplying medium comprising superhea-ted steam to distil volatiliz.- -able hyd'rocarbons'therefrom, transporting the resultant finely divided solid distillation residue in a fluidized stream from said distillation zone to a separate and confined combustion zone by means of 'hot combustion gases, obtained as hereinafter set forth, Vsupplying a gas containing free oxygen to said combustion zone and therein burning substantially all undistilled combustible material from said residue While conducting the latter downwardly co-untercurren-tly to the oxygen containing gas, withdrawing a vaporous stream of distillation products and heat supplying medium from said distillation zone, withdrawing hot combustion gases from said combustion zione and supplying at least a portion of `liad hot combustion gases Las the fluidizing medium for transporting said distillation residue from said distillation zone to said combustion zone, introducing said superheated steam to said distillation zone and the oxygen containing gas to said combustion zone each at a rate at which l the subdivided solid material in the descending mass within each of said zones is maintained in a hindered settling and freely flowing state, passing a stream of highly heated non-combustible residue from said combustion zone substantially without intentional cooling to a separate and confined heating zone and therein cooling said non-combustible residue by direct contact with an aqueous fluid, continuously feeding a stream of resulting superheated steam as the sole heatsupplying medium from said heating zone directly to said distilling zone, with the temperature of said steam being substantially above the maximum temperature prevailing in the distillation zone, and discharging finely divided solid residue at a substantially lowered temperature in a slurry stream from said heating zone.

6. A process for the distillation of oil shale which comprises continuously supplying a stream of oil shale subdivided into particles substantially of from 0.1 to 0.8 mm, diameter to a confined distillation zone and passingit in a fluidized dense phase downwardly through said zone in countercurrent flow to and in direct contact with a gasiform heat supplying medium comprising steam superheated to a temperature of from about 500 C. to about 650 C. and at a pressure of from about atmospheric to about 15 atmospheres in sufcient quantity to vaporize and expel substantially all distillable components of said oil shale, transporting the resultant finely divided distillation residue in a uidized stream from said distillation zone to a separate and confined combustion zone by means of hot combustion gases, obtained as hereinafter set forth, supplying a gas containing free oxygen tosaid combustion zone and therein burning substantially all undistilled combustible material from said residue while conducting the latter in a dense fluidized phase downwardly in countercurrent flow to the oxygen-containing gas, withdrawing a vaporous stream of distillation products and heat-supplying medium from said distillation zone, withdrawing hot combustion gases from said combustion zone and supplying at least a portion of 14 said combustion gases as the uidizing medium for transporting said distillation residue from the distillation zone to said combustion zone, introducing vsaid superheated steam to said distillation vrone and the oxygen-containing gas to said combustion zone each at a rate at which the solid material in the dense phase within each of said zones is maintained 'in a hindered settling a-nd freely flowing state, passing a stream of highly heated non-combustible residue from said combustion zone substantially without intentional `cooling to a separate and confined heating zone and therein cooling said non-combustile residue by direct contact with' an aqueous duid,

`continuously feeding a stream of resulting superyheated steam as the sole heat-supplying medium from said heating zone to said distillation zone, and discharging from said heating zone the finely divided solid residue at a substantially lower temperature Vand in a slurry stream provided by an unvaporized portion -of said aqueous fluid.

7. A process for the distillation of subdivided lsolid hydrocarbonaceous material which comprises: contacting said material in a distillation Zone with a gaseous heat-supplying medium to distil volatilizable hydrocarbons therefrom; transporting the resultant solid distillation residue by means of hot combustion gases, obtained as hereinafter described, to an independent combustion zone; supplying an oxygen-containing gas to said combustion zone and therein burning combustible material from said distillation residue; withdrawing hot combustion gases and hot non-combustible residue from said combustion zone; supplying at least a portion of said hot combustion gases as the transfer medium to transport said distillation residue from said distillation zone to said combustion zone; contacting said hot non-combustible residue in an independent heat exchange zone with a fluid medium to convert the latter into said gaseous heatsupplying medium; and introducing said gaseous heat-supplying medium into said distillation zone.

8. A process for the distillation of subdivided solid hydrocarbonaceous material which comprises: contacting said material in a distillation zone with superheated steam to distil volatilizable hydrocarbons therefrom; transporting the resultant solid distillation residue by means of hot combustion gases, obtained as hereinafter described, to an independent combustion Zone; supplying an oxygen-containing gas to said combustion zone and therein burning combustible material from said distillation residue; withdrawing hot combustion gases and hot non-comf bustible residue from said combustion zone; supplying at least a portion of said hot combustion gases as the transfer medium to transport said distillation residue from said distillation Zone to said combustion zone; contacting said hot noncombustible residue in an independent heat exchange zone with an aqueous fluid to convert the latter into said superheated steam; and introducing said superheated steam into said distillation zone. ,c

9. A process for the distillation of subdivided solid hydrocarbonaceous material which comprises: introducing said material to the upper portion of a confined distilling zone and therein contacting it with a gaseous heat-supplying medium to distil volatilizable hydrocarbons therefrom, withdrawing a stream of resultant solid distillation residue from the lower portion of said 75 distilling zone and commingling the same with a gaseous iiuidizing medium comprising hot combustion gases obtained as hereinafter set forth, transferring said residue stream fluidized in said gaseous medium to a separate conned combustion zone, supplying an oxygen-containing gas to said combustion zone and therein burning combustible material from said distillation residue, introducing said gaseous heat-supplying medium to the lower portion of said distilling zone and said oxygen-containing gas to the lower portion of said combustion Zone each at a rate at which the solid material within each of said zones is maintained in finely subdivided and freely flowing state, withdrawing a vaporous stream of distillation products and gasiform heat-supplying medium from the upper portion of said distilling zone while independently thereof discharging hot combustion gases from the upper portion of said separate combustion zone, I

16 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,524,784 Bartolomeis Feb. 3,1925 1,836,051 Trumble Dec. 15, 1931 1,901,169 Karrick Mar. 14, 1933 1,509,667 Catlin Sept. 23, 1924 1,950,558 Karrick Mar. 13, 1934 1,953,040 Brandegee Mar. 27, 1934 1,983,943 Odell Dec. 11, 1934 1,984,380 Odell Dec. 18, 1934 2,167,099 Benezech July 25, 1939 2,366,057 Russell Dec. 26, 1944 2,409,797 Roetheli Oct. 22, 1946 2,414,586 Egloff Jan. 21, 1947 2,432,135 Barr Dec. 9, 1947 FOREIGN PATENTS Number Country Date 283,259 Great Britain Jan. 2, 1928 286,404 Great Britain Mar. 8, 1928 419,444 Great Britain Nov. 8, 1934 484,050 Great Britain July 12, 1937 487,983 Great Britain June 29, 1938

Claims (1)

1. A PROCESS FOR THE TREATMENT OF SOLID HYDROCARBONACEOUS MATERIAL WHICH COMPRISES CONTINUQUSLY SUPPLYING A STREAM OF FINELY DIVIDED SOLID HYDROCARBONACEOUS MATERIAL OF RELATIVELY HIGH ASH CONTENT OF A CONFINED DISTILLING ZONE AND PASSING IT IN A DENSE MASS DOWNWARDLY THROUGH SAID ZONE IN DIRECT CONTACT WITH A GASIFORM HEATSUPPLYING MEDIUM COMPRISING SUPERHEATED STREAM AT DISTILLING TEMPERATURE, WITHDRAWING A STREAM OF HOT FINELY DIVIDED DISTILLATION RESIDUE FROM SAID DISTILLING ZONE AND COMMINGLING THE SAME WITH A HOT GASEOUS FLUIDIZING MEDIUM, TRANSFERRING SAID RESIDUE STREAM FLUIDIZED IN SAID GASEOUS FLUIDIZING MEDIUM AND SUBSTANTIALLY WITHOUT INTENTIONAL COOLING TO A SEPARATE CONFINED COMBUSTION ZONE AND THEREIN BURNING SUBSTANTIALLY ALL UNDISTILLED COMBUSTIBLE MATERIAL FROM SAID DISTILLATION RESIDUE WHILE CONDUCTING THE LATTER IN A DENSE MASS DOWNWARDLY IN DIRECT CONTACT WITH A FREE OXYGENCONTAINING GAS, INTRODUCING SAID SUPERHEATED STREAM TO THE LOWER PORTION OF SAID DISTILLING ZONE AND SAID OXYGEN-CONTAINING GAS TO THE LOWER PORTION OF SAID COMBUSTION ZONE EACH AT A RATE AT WHICH THE SOLID MATERIAL IN THE DENSE MASS WITHIN EACH OF SAID ZONES IS MAINTAINED IN FINELY SUBDIVIDED AND FREELY FLOWING STATE, WITHDRAWING A VAPOROUS STREAM OF DISTILLATION PRODUCTS AND GASIFORM HEAT-SUPPLYING MEDIUM FROM THE UPPER PORTION OF SAID DISTILLING ZONE WHILE INDEPENDENTLY THEREOF DISCHARGING HOT COMBUSTION GASES FROM THE UPPER PORTION OF SAID SEPARATE COMBUSTION ZONE, PASSING A STREAM OF HIGHLY HEATED NONCOMBUSTIBLE RESIDUE FROM SAID COMBUSTION ZONE SUBSTANTIALLY WITHOUT INTENTIONAL COOLING TO A SEPARATE AND CONFINED HEATING ZONE AND THEREIN COOLING SAID NON-COMBUSTIBLE RESIDUE BY DIRECT CONTACT WITH WATER IN AN AMOUNT IN EXCESS OF THAT REQUIRED TO GENERATE SAID SUPERHEATED STEAM, CONTINUOUSLY FEEDING A STREAM OF THE RESULTANT SUPERHEATED STREAM FROM SAID HEATING ZONE DIRECTLY TO SAID DISTILLING ZONE, AND DISCHARGING A SLURRY OF FINELY DIVIDED SOLID RESIDUE AND WATER A A SUBSTANTIALLY LOWERED TEMPERATURE FROM SAID HEATING ZONE.

Images