US2550432A - Process for recovery of hydrocarbon oil from shale - Google Patents

Description

April 24, 1951 w. l. THOMPSON PROCESS FOR RECOVERY OF' HYDROCARBON OIL FROM SHALE Filed Aug. lO, 1944 ru, we nm eo vb n au U n O s P m O m .L m iu. .Hb m

Patented pr. 24, 1951 PROCESS ros RECOVERY QF HYQBQ- 95333951 9.1L FROM' llt? William I. Thompson, Elizabeth, N. J., assgnor toStandard .Oil Development Company, a. coriporation of Delaware Appneaiqn Aggtst io, 1944, serial No. 514,8,584 2 claims. (o1. 2oz- 14) The object of the present invention is to providlea cess and suitable apparatus therefor for recovering hydrocarbon oil"f`rom tar sands aid/ r'shalelf """Prior'te my invention others had proposed methods for recovering hydrocarbon oils from tarfsands and shales. Usually the prior methods Yinvlved4 heating of the oil-,containing material 'to'convertthe hydrocarbon oilorming material 'into' volatile constituents and a fixed carbon. These o'peratioris were performed in a retort in which ythe shale or tar sand Was'treated in a processessentially intermittent. According to my presen-t invention, I provide a process" and I'suitable apparatus therefor whereby tar sands and/or shales from which hydrocarbon cils are to be recovered, are heated in powdered form, or at least in divided form, to a temperature ysufficiently high to ca use coking of"`tlie' "hydrocarbon oil-forming constituents tial ingresen that the hyeroear'bon oir-1S eent'e'rted'to a velatile product and atar or ceke. llv'ola'tile hydrocarbons are then treated ac'- co ing -to the customary oil renery vpractice a-iidseparated into various'fractions', suc-h as normally gaseous hydrocarbons, gasoline 'consti-'tuenta 'gas oil, tar, coke, and the like, as desirefd. 'lih'e fixed vcarbon or coke which is left oir-the sander spent shalei is burnt to supply heat `f'orlthe process.`

The .present application describes in detail an arrangement of' apparatus elements for using theheating value of the coke to carry out the 'cokingreaction In general, the method'com'- prises van application of the so-called fluidsolid's`ltech nique 'to this problem. By fluidsollids technique, I mean an operation in Which the sol-id ymaterial undergoing treatment is maintained il'n la dense suspension in a delayed settling Zone'by eontrolling'the velocity of a gasiforn material Yflcjvving therethrough at a t'suilciently ldtv'value that the solid material forms a dense, turbulent, mo'bile mass of solid in gas resembling a'boiling" liquid', all of Which will morefiilly yarid atlarge appear hereinafter. i A"In the accompanying drawing, `I lfiave shown diagrammatically a suitable apparatus` in vv ich l red mediteren ef my .inveiition maybe ,d into' praqiealeffet. f Benning 4in A,defalil t0 the drawing, .a liar .Send er Va'slialle ,the @latter Ain subdividediorrn having ieleslze of, say,V 100 mesh up to 1A; linchfin roducedinto the present'ksysteni i .and thfenfedischargsdietd.aies@ which it is' withdrawn into' a screw lll conveyor 3, which may "be of the compression sere'w'type. The feeder charges the sand or't'a'r ina line 4 where itinixesv with hot, burnt and spent shale or tar sand from line 5 and Subsc-"- quently with a liquid product of the coking which is charged into line 4 from line 6, the sourceoi this liquid material in line 6' being more 'fully identiiied hereinafter. At this point `I will simply point out that it is a hydrocarbon in liquid form produced as a result'of coking'." The mix# ture of spent shale or tar sand 'and hydrocarbon, the' latterbeing essentially vaporized 'by the hot spent shaleortar `sand,`formsa suspersic-n in iine d, which suspension is carried'into the bottom of coking drum l0 which, as Vcan be seen, is essentially a cylindrical shell or case havl ing conical upper and lower sections. In the colring zone l@ the linear velocity of the gasiform hiaterial is controlled within the limits of'irom 1A to l0 it. per second, depending upon the paiticle size of thesolids therein contained. If, for instance, the solids have a particle size of around 200 mesh, the Vgas velocity inthe vessel I0 is 'froin 11/2 to 3ft. per second, which will cause the fo'rmation of the dense, turbulent, fluidized mass which I have previously referred'to. Actually another .way of describing the reaction Vessell is to say that it is a delayed settler Whereinthe velocity of the gas is insulicient to carry the main bull; of theproduct overhead and out of the reactorbut SuCient, nevertheless, to support ai body of the solid in the reaction Zone to forinthe dense phasesuspensionfof course, Iif the' yparticle size is' 1A; inch or larger on the average'ih diameter, the gas velocity must b'sorne wliat higher, say u'p-"to l0 vto'12 ftf'per L secon'd. In the' case Where the shale or tar sand 4is in the form of relatively large aggregatesth'e heat which it is confronted inte'iaetieri zone sery's te ydecompose the agglutinants contained the ramps Qfshale, andthe like and .fo clause th Shale ,and thelist: te disintegrate" physically.

A temperature of 900 F. t'o'1000"7 F., approggimately, is maintained Within the reactionl Zone i6- The presser? .is 'notgeiiieal and ,may 1b.@ tf rnespheric ohr e' 4few pounds above atmospheric, in @ther werds, -Sueient i0 Overcome re's drops in the system. The shale or .sane remains resident in the reaction zone for a `sufcientpe riod ottime to r,efiectthe desired conversion'. `yIn the oase of tar sand, this residence'timeis from 1 to 3 minutes. The resultffof the cokijng orhe'atingoperation in`.,.the.vess,el l0 is to convert lhigh molecular Weight constituents of ,the'shale'jor sand into volatile hydrocarbons which are withdrawn through line l2 and into a spent material which is withdrawn through a draw-olf pipe 90.

Referring again to the interior of the reaction zone I0, I provide a foraminous member G, which may be a screen or grid, to aid in the distribution of the gasiform material in the reaction zone, and under the ow conditions which I have named .there will be an upper dense phase level, which I have indicated at L which is xed by fixing the amount of powdered shale or sand which is maintained in the reaction zone and by the velocity of the gas. Essentially, when the velocity of the gas is sufficiently low to maintain the dense phase suspension previously referred to, the height of the level L is controlled by the rate at which solid material is withdrawn. A controlled amount of material is Withdrawn through lll and is discharged into a pipe I5 where it mixes with air or other oxygen-containing gas, as will subsequently appear. It should be pointed out, however, that in order to cause good ilowability in line I4, the same should be provided with a number of taps (not shown) into which a slow current of gasiform material, such as flue gas, steam, normally gaseous hydrocarbons, and the like, are forced to prevent bridging and/or plugging of draw-off pipe le. rIhe shale or tar sand, as stated, is discharged into air stream l Where it forms a suspension which is then conveyed into the bottom of a combustion zone 20. This combustion zone is similar in shape and construction to coking zone lli, that is to say, it consists of a cylindrical case or shell having conical upper and lower sections and is also provided with a distribution screen or grid G. Here also the velocity of the air and the amount of shale maintained in the combustion Zone 20 is adjusted so as to form a dense phase upper suspension at L, in which suspension the fixed carbon on the sand or shale is consumed by combustion thus causing heating of the spent shale to a temperature of l000 Ii'. to 1175" F., whereupon the spent shale is Withdrawn through pipe 5 and mixed with the fresh shale or tar sand and recycled to coking drum l0, the hot shale providing the heat necessary to support the pyrolitic action taking place in coking or distilling vessel I0.

The amount of spent shale circulated to the combustion Zone by line I6 and admixed with the cold fresh shale or tar sand in line f should be sufficient to raise the temperature of the mixture to the reactor temperature and to supply heat for the cracking reaction. This would require in the order of from 5 to 10 parts by weight of hot spent shale or tar sand per part of cold fresh shale or sand. It is also pointed out that draw-01T pipe 5 is provided with a flow control valve l' which controls, of course, the amount of spent shale Withdrawn through line 5 and is also provided with a plurality of taps into which a gas, such as air or ue gas, may be continuously fed to prevent bridging or plugging of draw-off pipe 5.

Referring back again to distillation and/or coking zone l0, the gasiform material above the level L becomes or is greatly depleted in solid content since the main body of the solids remains in the suspension below L. Thus by controlling the amount of solid and the velocity in lil, as previously indicated, the upper dense phase level will be at L and will have a weight of -25 lbs. per cubic foot. Above L the concentration of solid in the gas may be lowered to the extent that it weighs only about 0.025 to 0.030 lb. per

cubic foot. This dilute suspension passes through a number of cyclones which I have indicated at C disposed in the upper conical section of i0, which cyclones cause the separation of the solid from the gas by centrifugal action and the return by gravity of the separated solid to the main body between G and L, While the gasiform material is Withdrawn overhead through line 30 containing only minor amounts of entrained solid. It is at a temperature of around 900 F., to 975 F. and it passes into a knockdown drum or cooler 3l where it is partially cooled, say to a temperature of 650 F. for the purpose of condensing out the heavier oils, which oils will contain the unseparated lines. This slurry is withdrawn from the bottom and thence is forced by pump 33 into line 5 for recycling to I0, as previously indicated.

Overhead from knockdown drum 3l, I withdraw through line 35 a hydrocarbon fraction in gasiform state which is then discharged into a heat exchanger 40 in which further cooling and condensation takes place. The product from this exchanger, which is part liquid and part vapor, is withdrawn through line 42 and discharged into a Water quench zone 45 from which I withdraw normally gaseous hydrocarbons overhead through line 46, while the quenched material is withdrawn through line lll. The quenching water is introduced through line 50. The quenched material is then pumped by pump 48 into a separator 5l from which the hydrocarbon oil may be Withdrawn through line 52 while the water is withdrawn through line 53.

Referring to the material in line 6, a portion thereof may be bypassed through line 6I into a heat exchanger 62 in which it is cooled to a temperature of 300 F. to 500 F. and thence discharged via line 63 into knockdown drum 3l.

Heat exchangers il'and 62 are cooled by means or-water from drum 64 introduced through lines 65 and 66, respectively. Steam generated in heat exchangers @0 and 62 at about 125 lbs. per square inch is returned to drum 6d through lines 61 and 68, respectively, and withdrawn from the drum through line 69.

Referring again to combustion zone 20, above L there is a second dense phase suspension which I have designated as S2. This is formed by interposing a second foraminous member G2 at a point spaced above L and here also by controlling velocity and the amount of solid there is a second dense phase suspension and an upper level at L2. In other words, in combustion zone 20 I have two separated dense phase suspensions. Interposed, as will be noted, in the second and/or upper dense phase suspension is a coil 10 containing water, which water is converted into steam by heat interchange with the hot spent shale, which steam is discharged into vessel l2 and withdrawn through line 13, the water being fed to the coil through line lll. Thus I have provided means for forming a quantity of steam which may be used in my present process. Above L2 the concentration of solid in the gas, Which in this case is regeneration vapors, is greatly depleted so that whereas the suspension Weighs from 15-25 lbs. per cubic foot in both dense phase suspensions, in the space above Lz' it may be of the order of a density of from 0.025 to 0.030 lb. per cubic foot, and this dilute suspension is then forced through one or more centrifugal separators C' disposed in the upper portion of 22 Where thesuspension in passing through is separated from entrained solids which are returned to the upper dense phase suspension, while the regeneration fumes are withdrawn through line 88, thence passed through a gas turbine 8| before they are vented from the system through line 82 thus providing a portion of the power required to operate air compressor 84 which pumps air to the preheating zone 92 through line 99, as described above, and to combustion zone 20, and to storage zone |52, described below. The turbine'l may be operated on the same shaft as steam turbine 83 which operates compressor 84.

Referring again to distillation and/or coking zone l0, the spent shale to be rejected from the system is withdrawn through a line 90 and discharged into a preheater 92 where it contacts in the form of a dense suspension, the air entering said preheater through line 94. The air contacts the hot shale and is preheated thereby and is withdrawn through line |90, and it is this preheated air which eventually mixes with the spent shale withdrawn from distillation zone I8 through line |11 to form the suspension which is conducted to combustion zone 2i), as previously described.

In preheating zone 92, the velocity of the air is fixed within the limits of from 1/2 to 10 ft. per second, preferably 11/2 to 3 ft. per second, so as to form the dense phase suspension having` an upper level at L. Here also I provide a screen G which serves to aid in the distribution of the air. In order to provide a further quantity of steam for use in the process or for some other useful purpose, I may interpose a water coil I5 in the mass of dense suspension, in which water is preheated or converted to steam. The spent shale is withdrawn from preheater 92 through line |30, mixed with air from line |3| and conducted into the top of a storage Vessel |52, thence withdrawn through line |60 and discharged into a car or other conveyance |62 andwithdrawn from the system. Here also, in order to recover heat for some useful purpose, I dispose within the storage zone |52 a water coil |70 in which boiler feed water may be preheated.

Thus I have described an operation for converting shale or tar sands into hydrocarbon oils which may be subsequently processed to produce gasoline, gas oil, heating oil, and the like.

My present invention involves essentially the following novel features:

1. Utilization of the fluid-solid technique to treat the raw material continuously and eiliciently in an economical manner.

2. To make the system substantially self-supporting regarding heat requirements by burning the fixed carbon on the spent shale or tar sands.

3. Economizing in utilities by utilizing the energy of regeneration fumes and hot spent shale for operating waste heat boilers and turbines.

My process is suited for recovering valuable hydrocarbon oils from natural deposits known as Athabaska sands, oil shales, and the like.

Many modications of my invention will be apparent to those skilled in the art without departing from the spirit thereof.

What I claim is:

1. In the continuous process of recovering hydrocarbon oil from oil-bearing minerals by distilling said minerals in a luidized bed of solids maintained in a distillation zone, withdrawing spent solid residue, burning withdrawn residue with a combustion-supporting gas in a iluidized bed maintained in a combustion zone, and returning heated residue from said combustion zone to said distillation zone to supply heat to the latter, the improvement which comprises preheating said combustion-supporting gas in direct y contact with hot fluidized solid distillation residue withdrawn from said distillation zone, carrying out said burning in two separate superimposed fluid beds within said combustion zone, vaporizing a liquid by heat exchange with the upper one of said superimposed beds, transferring substantially all the heat generated in the lower one of said superimposed beds to the materials forming said lower superimposed bed, withdrawing all of said returning heated residue from` said lower superimposed bed, cooling the volatile eiuent of said distillation zone just suiiiciently to condense a heavy oil fraction, mixing said returning heated residue with said minerals and said condensed oil fraction outside said Zones to Vaporize said oil fraction and to form a dilute solids-in-gas suspension, and passing the suspension so formed to said distillation zone.

2. The method of yclaim 1 in which hot fumes are Withdrawn from the combustion zone and passed through a system adapted to recover at least a portion of their energy content as kinetic energy. A

WILLIAM I. THOMPSON.

REFERENCES CITED The following references are of record in the Ile lof this patent:

UNITED STATES PATENTS Number Y' Name Date 1,432,101 Danchwardt Oct. 17, 1922 1,458,983 Kirby June 19, 1923 1,669,023 Runge May 8, 1928 1,704,956 Trumble Mar. 12, 1929 1,824,282 Loughrey Sept. 22, 1931 1,899,887 Thiele Feb. 28, 1933 1,950,558 Karrick Mar. 13, 1934 1,958,918 Karrick May 15, 1934 1,983,943 Odell Dec. 11, 1934 2,367,281 Johnson Jan. 16, 1945 2,406,810 Day Sept. 3, 1946 2,480,670 Peck Aug. 30, 1949 FOREIGN PATENTS Number Country Date 189,542 Great Britain Dec. 1, 1922

Claims (1)

1. IN THE CONTINUOUS PROCESS OF RECOVERING HYDROCARBON OIL FROM OIL-BEARING MINERALS BY DISTILLING SAID MINERALS IN A FLUIDIZED BED OF SOLIDS MAINTAINED IN A DISTILLATION ZONE, WITHDRAWING SPENT SOLID RESIDUE, BURNING WITHDRAWN RESIDUE WITH A COMBUSTION-SUPPORTING GAS IN A FLUIDIZED BED MAINTAINED IN A COMBUSTION ZONE, AND RETURNING HEATED RESIDUE FROM SAID COMBUSTION ZONE TO SAID DISTILLATION ZONE TO SUPPLY HEAT TO THE LATTER, THE IMPROVEMENT WHICH COMPRISES PREHEATING SAID COMBUSTION-SUPPORTING GAS IN DIRECT CONTACT WITH HOT FLUIDIZED SOLID DISTILLATION RESIDUE WITHDRAWN FROM SAID DISTILLATION ZONE, CARRYING OUT SAID BURNING IN TWO SEPARATE SUPERIMPOSED FLUID BEDS WITHIN SAID COMBUSTION ZONE, CARRYING A LIQUID BY HEAT EXCHANGE WITH THE UPPER ONE OF SAID SUPERIMPOSED BED, WITHDRAWING ALL OF TIALLY ALL THE HEAT GENERATED IN THE LOWER ONE OF SAID SUPERIMPOSED BEDS TO THE MATERIALS FORMING SAID LOWER SUPERIMPOSED BED, WITHDRAWING ALL OF SAID RETURNING HEATED RESIDUE FROM SAID LOWER SUPERIMPOSED BED, COOLING THE VOLATILE EFFLUENT OF SAID DISTILLATION ZONE JUST SUFFICIENT TO CONDENSE A HEAVY OIL FRACTION, MIXING AND RETURNING HEATED RESIDUE WITH SAID MINERALS AND SAID CONDENSED OIL FRACTION OUTSIDE SAID ZONES TO VAPORIZE SAID OIL FRACTION AND TO FORM A DILUTE SOLIDS-IN-GAS SUSPENSION, AND PASSING THE SUSPENSION SO FORMED TO SAID DISTILLATION ZONE.

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