US3008894A

US3008894A - Method and apparatus for producing oil from solids

Info

Publication number: US3008894A
Application number: US736497A
Authority: US
Inventors: Jr William J Culbertson
Original assignee: Oil Shale Corp
Current assignee: Oil Shale Corp
Priority date: 1958-05-20
Filing date: 1958-05-20
Publication date: 1961-11-14
Anticipated expiration: 1978-11-14

Description

N0 14, 1961 w. J. cuLBERTsoN, JR 3,008,894

METHOD AND APPARATUS FOR PRODUCING OIL FROM SOLIDS Filed May 20, 19.58 2 Sheets-Sheet 1 WJ" xm/:mp5s

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3,008,894 METHOD AND APPARATUS FR PRGDUCING OlL FROM SOLDS William J. Culbertson, Jr., Denver, Colo., assignor, by

mesne assignments, to The @il Shale Corporation,

Beverly Hills, Calif., a corporation of Nevada Filed May 20, 1953, Ser. No. 736,497 34 Claims. (Cl. 208-11) This application relates to apparatus and processes `for producing oil and gases from solid materials leaving a carbonaceous residue after pyrolysis and relate particularly to apparatus and contiguous processes for producing cracked oils from such so-lid materials as oil shale, tar-sand, peat, etc. The term carbonaceous residue denotes a residue which includes xed combustible carbon.

inasmuch as solid materials, such as oil shale, are found Some distance from the relinery centers, it is extremely desirable to thermally crack the oil in such a manner as to reduce its viscosity and/or pour point prior to its introduction into a pipe line for ease in transportation. Such a thermal cracking is sometimes referred to as visbreaking, or if the cracking is prolonged, as coking.

Often it is desirable to thermally crack such materials as liquid shale oil after they are produced from solids by pyrolysis or retorting but before they are hydrogenated. Such a cracking step reduces the tendency for coke to be laid down on the hydrogenation catalyst and in other parts of the hydrogenation `apparatus and reduces the frequency of shutdowns for its removal.

It is also desirable in some cases to crack oils at rather high temperatures after they are produced from solid materials by pyrolysis in order to obtain useful chemicals and intermediates.

While thermal cracking of shale oil or of oil vapors and gases from such solid materials as oil shale, in combination with a pyrolyzing step, is deiinitely desirable, certain problems are incident to the combined pyrolyzing and cracking process. One of the problems encountered is the following: as the thermal cracking of the oil vapors and gases occurs, coke and tarry substances are produced, the presence of coke and tar being one of the main causes of eventual shutdown of the cracking phase of the process. For these coke and tarry residue products will clog vital parts of the cracking equipment, and may also cause overheating and possible' bursting of the equipment. The cost of shutdown is extremely great and is therefore to be avoided.

A second problem encountered is that of dust formation in the pyrolysis step, the dust, in the usual prior art processes being entrained with the oil vapors and gases leaving the pwolysis phase of the process, the prior art requiring the use of dust-separating equipment for the removal.

Bearing in mind the foregoing facts, it is a major bject of the present invention to provide a simpliiied and economical continuous process for the combined pyrolysis and thermal cracking of solid materials, which leave a carbonaceous residue, upon pyrolysis.

It is another major object of this invention to provide au overall process wherein increased thermal eiciency is realized by combining pyrolyzing and thermal cracking operations, without condensation of the oil product prior to the cracking operations.

Another major object of the present invention is to provide in a combined pyrolyzing and cracking process an efficient, simple and inexpensive method of removing coke and tar as it is produced in the cracking phase yof the process, thereby substantially reducing the need for shutdown, cleanout, and other attendant problems.

nited States Patent 0 Mice provide a combined pyrolyzing and cracking process for solid materials, such as oil shale and the like, wherein coke produced during a thermal cracking stage is burned to provide additional heat for use in the retorting process, or for other purposes, resulting in an overall increased thermal eiiciency, and wherein the more volatile tars produced during the thermal cracking stage are gasied and cracked, resulting in a greater overall yield of valuable cracked oil and gases.

Still another object of the present invention is to provide a process wherein dust particles, resulting from the pyrolyzing operation, are separated from the crude oil vapors andy gases in an improved and simplied manner, which considerably reduces the necessary capacity of dust-removal equipment, usually required, and in many instances, completely eliminates the need for such dustremoval equipment.

These and other objects of the present invention will be more clearly understood by referring to the following description, and to the accompanying drawings, in which:

FIGURE 1 is a schematic ilowsheet of one form of my process;

FlGURE is a schematic ilowsheet of a modiiied form of my process; and

FIGURE 3 is a iiowsheet of a second modied form of my process showing possible forms of `apparatus that are employed.

In general, my combined pyrolyzing and thermal cracking continuous process employs one or more streams of hot heat-transfer bodies for the furnishing of substantially all of the heat requirements of the process. It is found that the use of such circulating heat bodies in the combined pyrolyzing and cracking process, to be described, is the primary reason for the substantial reduction in clogging and overheating of the cracking equipment, due to coke and tar formation, and is the primary reason for the substantial removal of dust from the oil vapors and gases produced in the process.

Referring now to FIGURE 1, the process will be described with particular reference to oil shale. Fresh yoil shale -or the like continuously enters a preheating zone 10, along the line 12, at ambient temperatures. The fresh oil shale is intimately commingled with a plurality of substantially hotter heat-carrying bodies continuously entering the preheating zone along .the line 14 rat a temperature usually lying between approximately -800 `and 1000 F. The substantially hotter heat-carrying bodies are hard, wear-resistant and heat-resistant, and are made, for example, of steel, metal alloys, or ceramic materials. These bodies are generally spherical in configuration and will be sometimes referred to hereinafter as balls.

the oil shale commences to become sticky or gummy' and it is undesirable for this condition to exist in .the preheated, while avoiding the above-described disadand transporting lmaterial in such condition to other steps of the process. With some types of oil shale, the

- upper temperature limit to which the oil shalecan be Still a further object of the present invention is to preheated, while avoiding the above-described disadvantages, is approximately 700 F.

The ball size is generally somewhat larger than the average inlet oil shale size, and is of the order of 1% of an inch to one inch. The oil shale may then be separated from the balls, after the preheating step, by standard screening methods or by other suitable means, such as by elutriation. The oil shale leaves the preheating zone continuously along the line 13 and is fed directly to the pyrolyzing step in zone 20.

The balls, which are now considerably cooled and have a temperature lying between approximately 450 and 700 F., are sent, via line 22, to a ball heating step in zone 24. The balls are heated in the ball heating zone 24 by means of products of combustion of the carbonaceous residue of the oil shale and of coke and non-volatile tars producing during the cracking, as will be described more fully. The ball temperature, after reheating, preferably lies between 1000 and l400 F. All of the very hot balls are removed from Zone 24 via line 2S. All or part of these every hot balls are then introduced into the pyrolyzing zone 20 via line 26 and are intimately commingled, in parallel flow, with the preheated oil shale.

Part of the hot balls may by-pass the pyrolyzing zone 20 completely, being sent to the cracking zone 30 via

lines

27 and 32. The amount of hot balls by-passing the pyrolyzing zone 20 varies greatly from a zero amount to approximately 50% of the total balls ernployed, depending on the temperatures desired in both the pyrolysis and cracking zones 20 and 30, respectively. The by-pass feature will be described in more detail hereafter. The process Will be confined, for the present, to a zero by-pass, that is to say, to a process wherein the entire amount of circulating balls passes through the pyrolysis zone 20. The pyrolyzing phase of the process is preferably conducted in a horizontal or inclined rotating drum similar to the pre-heating drum.

Counterflow of balls and oil shale may also be used, although this mode of heat transfer is not presently preferred.

The oil shale is pyrolyzed, by contact with the hot balls, the oil vapor and gas effluent, leaving the pyrolyzing zone 20 along the line 28, to be sent directly in the vapor phase, to the cracking step in zone 30. The temperature of the pyrolyzed oil vapors and gases usually lies between 750 and 950 F., The oil vapors and gases may have a small amount (of the order of several percent) of liquid suspended therein. However, for purposes of this application, such a vapor, with very small amounts of liquid, will be referred to as a vapor phase.

All of the circulating balls, which are now cooled to a temperature of between 850 and 1050 F., are sent directly from the pyrolysis zone 20 to the cracking zone 30 via line 32.

The cracking preferably occurs in the vapor phase at substantially atmospheric pressure. The 750 to 950 F. oil vapors and gases Contact the 850 to l050 F. balls directly for a predetermined period of time, e.g., from 20 seconds to 2 minutes, and a cracking of the oil vapors and gases results. The balls, oils and gases, can contact each other either in coow, counterflow or crossflow in the cracking zone 30, the counterflow mode of operation being shown schematically in FIG- URE l.

The cracked oil vapors and gases leave the cracking zone 30, via the line 34, having a temperature of approximately 825 to 1000 F., to be sent to further process steps such as quenching, condensation, etc., in preparation for transportation by pipelines to refinery or market.

The pour point of the oil leaving line 34 is approximately 20 F., or more, lower than the pour point of the oil leaving the pyrolysis step. This, of course, improves the pumpability of the oil also. These changes in the character of the oil are due directly to the cracking taking place in the zone 30.

The balls, upon leaving the cracking zone, have an outlet temperature of approximately 800 to 1000'a F., i.e. 50 to 100 below their inlet temperature, and are returned along line 14 to the preheating step in zone 10, which has been previously described.

As mentioned previously, during the cracking of the oil vapors and gases, a substantial amount of coke is formed, as well as tarry substances. The amount of coke and tars produced ranges between 1% to 5% of the total oil vapors and gases. These substances would ordinarily deposit on the walls of the cracking apparatus, such as a reaction chamber or a tube still, and eventually clog such apparatus. Further, When cracking in a tube still, the coke deposits on the walls of the still greatly increase the temperature of these walls due to reduced heat transfer through the walls, and a failure of the tube wall due to overheating can occur.

However, in my process the coke and tarry substances are deposited upon the balls in the cracking zone to a far greater extent than on the walls of the cracking equipment. The coke and tarry substances are thus carried from the cracking Zone 30 by means of the balls themselves, the balls being sent to the preheating zone 10, as described.

Some cracking of the oil vapors and gases occurs in the pyrolysis Zone 20 resulting in small amounts of coke and tar being deposited upon the balls in the pyrolysis phase of the process. However, it should be emphasized that the great bulk of the coke and tarry substances is deposited during the cracking phase of the process in the cracking zone 30, and is deposited upon the balls passing through the cracking zone at this time.

The coke produced during the cracking phase of the process and deposited on the balls comprises substantially all combustible carbon, and the tarry substances cornprise generally speaking, heavy hydrocarbons and heavy nitrogen and sulfur-containing organic compounds. The coke can be burned to extract heat therefrom and increase the thermal eficiency of the process, while some of the tars can be removed, as will be described, to further increase the yield of oil vapors and gases. In this regard, it is found that when the balls, having coke and tar deposited thereon, are introduced into the preheating zone l0 to be intimately admixed with fresh oil shale, the fresh oil shale, in addition to being preheated by the balls, actually removes the bulk of the coke and tar from the balls by means of a rubbing, scraping or wiping action. The fresh oil shale is thus found to have a scouring effect on the balls and effectively cleans the balls of substantially all the coke and tar deposited thereon in the pyrolysis and cracking steps.

The clean balls are then led from the preheating zone 10, -along line 22, to the ball heating zone 24, as previously described, and the preheated oil shale, carrying the coke and tars, is sent to the pyrolyzing zone 20, via line 18, for the pyrolysis step.

Pyrolysis of the preheated oil shale occurs, as previously described, thereby resulting in the production of oil vapors and gases. The more volatile tars, carried with the oil shale, are also pyrolyzed simultaneously with the pyrolysis of the oil shale, thereby increasing the total yield of oil. For purposes of this specification and the annexed claims, the volatile tars are defined herein `as those tars, deposited on the balls in the cracking apparatus, that are volatilized or pyrolyzed under the conditions of pyrolysis previously described.

As is well known, a carbonaceous residue remains after oil shale is pyrolyzed, the carbonaceous residue from oil shale being hereinafter referred to as carbonaceous shale residue. As has been mentioned, the oil shale originally was crushed to a smaller average mesh size than the balls, and the carbonaceous shale residue therefore has also a smaller average mesh size than the balls. In addition, during the pyrolysis especially, the balls being composed of a hard, wear-resisting composition, crush and grind the oil shale into a substantially smaller average particle size than their initial size. Carbonaceous shale residue is thus readily separated from the balls by screening, elutriation `orother suitable methods, after `the pyrolysis. The carbonaceous shale residue produced during the pyrolysis leaves the pyrolyzing zone 20, via line 38, at a temperature lying between approximately 750 to 950 F., and carries'with it the coke and those tars, previously deposited on the balls in 4the cracking apparatus, which were not volatilized or pyrolyzed dur ing the pyrolysis step, these tars being hereinafter referred to as the non-volatile tars.

The carbonaceous shale residue, coke and non-volatile tars are then sent to a combustion step or zone 40 where they are combusted in the presence of air or other free oxygen-containing gas thereby producing extremely hot gases such as carbon monoxide and carbon dioxide as Well as hot solid ash. The temperature of the hot gases and ash lies between approximately 1200 to 1600 F. The heat from the products of combustion, that is, the hot gases and/or the hot ash, is transferred directly or indirectly to the balls in the ball heating zone 24 to thereby heat the balls to the desired temperature, which as stated previously ranges between 1000 and 1400 F. The hot gases and ash are sent to .the ball heating zone 24 along a common conduit 42, while the exhaust gases and cooled ash leave the zone 24 along the line 46 at a temperature lying between approximately 550 and 900 F. The heated balls are then sent to the pyrolyzing, cracking and preheating steps, `as described, and the process is repeated.

The air or other free oxygen-containing gas, employed for the combustion, may be preheated by means of the hot exhaust gases and/or hot ash, -if desired.

It is also desirable to utilize the heat of the other products of the pyrolysis, or heat from extraneous sources, in some instances, for the heating of the balls.

A fresh ball inlet 47 and Worn ball outlet `48 are provided leading into and out of line 22, respectively.

A specic example of the process shown .in FIGURE 1 (with no flow of balls along line 27) follows:

One ton of minus 1A inch, twenty-five gall-ons per ton, oil shale, at approximately 60 F., enters the preheating zone in a continuous stream to contact 1.4 tons of 5A; inch 960 F. aluminum-oxide containing ceramic balls, continuously entering the preheating zone Via line The oil shale is thus preheated.

The preheated oil shale leaves zone 10 continuously via line 1S, at a temperature of about 505 F. and enters the pyrolyzing zone 20. The Water vapor driven 01T amounts to approximately 10% of the total water present, and runs about two pounds for Colorado oil shale.

The balls leave the preheating zone 104 in a continuous stream at a temperature of 600 F., and are sent to the ball heating 4zone 24, along line 22, for reheating. The balls yare reheated to a temperature of 1300 F., by the products of combustion of the 'carbonaceous shale residue, and by the products of combustion of the Vcoke and non-volatile tars produced in Athe cracking zone 30 and produced to a Vsmall extent in pyrolysis zone 20. These 1300" F. balls are then iadmxed with the preheated oil shale in the pyrolysis zone 20.

Approximately 200 pounds of oil vapors andlgases are formed during the pyrolysis land leave the zone at a temperature of 850 F., for the cracking zone 30 via line 28. The balls leave the pyrolyzing zone 20 at a temperature of 1000 Ff., fand are sent to the `cracking zone 30 where the oil vapors and gases contact the balls lfor a period of sixty seconds. Y l

The oil vapors and gases are thus cracked and leave the zone 30, at a'tempe'rature of approximately 960 F., while the balls also leave the cracking zone at a temperature of approximately 960 F., and are returned to the preheating zone 10 in a continuous stream, via line 14,

e for preheating fresh oil shale. Upon admixture of the balls with fresh oil shale, the coke and tars previously deposited on the balls during the cracking are removed. Approximately 6 pounds of coke and tars are transferred to .the fresh oil shale in this manner, and are brought into the pyrolyzing zone 20.

During the pyrolyzing step, some of the tars are volatilized or pyrolyzed and approximately 1798 pounds of carbonaceous shale residue (containing approximatel)l 50 pounds of combustible carbon) are produced and leave zone 20, via line 38, at la temperature of 850 F. Also, the coke and remaining tars leave with the carbonaceous shale residue for combustion in zone 40. The hot gases and ash produced in combustion zone 40 leave along line 42 at a temperature of 1400 F., and reheat the balls in zone 24, as described.

The exhaust gases and ash leave the zone 24 via line 46 at a temperature of approximately 800 F., and, by a heat exchanger (not shown) may furnish heat for the air used for combustion. rlhe air may thus be preheated to a temperature of 500 F., prior to its entry into the combustion zone 40, if desired, and to do so would allow extraction of excess heat from combustion zone 40- by air or steam cooling coils.

Mention has previously been mad-e that dust removal from the retort vapors and gases is accomplished to a great degree without the need for additional equipment. It is found that the bulk of the dust entrained from the pyrolyzing zone 20 along with the oil vapors and gases, is eectively removed from these oil vapors and gases in the cracking zone 30 by means of contact with the ball stream moving through the :cracking zone. The dust is carried with the balls, via line 14, into the preheating zone 10 in FIGURE 1.

While parallel flow of oil sh'ale and balls both in the preheating steps and in the pyrolyzing steps has been described and is presently preferred, counterow of balls and oil shale, either in the preheating step or in the pyrolyzing step, or both, can also be utilized.

By means of the above-described cracking process, it is possible to reduce the pour point of the shale oil by about 15 F.

In order to increase the average inlet temperature of the balls entering the cracking zone 30, and thereby cause thermal cracking to occur at higher temperatures, a predetermined portion of the total number of balls sent from the outlet line 25 of ball heating zone 24, is diverted into the line Z7, and from thence passes into the cracking zone 30 via line 32. Those balls passing along l-ine 27 `completely by-pass the pyrolyzing zone 20 and thus are not appreciably reduced in temperature in going from the ball-heating zone 24 to the cracking zone 30.

It will be recalled that the ratio of balls to oil shale in the FIGURE 1 embodiment, Without any by-pass of bal-ls via line 27, lies betwen 3:1 'and 1:1, and is preferably -about 1.4: 1. When employing the bypass feature, the ratio of balls to oil shale, passing through the pyrolysis zone 20, is still maintained betweenk 3:1 and 1:1, and is preferably somewhat less than 1.441. The ball to shale ratio should preferably be made somewhat smaller as the proportion of balls by-passed around the pyrol'ysis Zone 20 is increased, because the temperature of the preheated -oil shale tends to increase with the increased by-passing due to an increased ball temperature in line 14 from the cracking zone 30, as well as because of the increased ball to shale rat-io flowing into the preheater zone 10. Indeed, it may in some cases be desirable to reduce the contact time of the oil shale with the balls in the preheater zone Y 10 or to by-pass some of the balls around the preheating 7 the pyrolyzing zone 20, and that a preferred ball-shale ratio of l.25:1 is to be used in the pyrolyzing zone, the total ball toshale ratio will then be approximately 1.56: 1.

'Ihe percentage of the total amount of balls in the system that can be sent along by-pass line 27 varies from zero, as previously described up to approximately 50%. Thus, for a 50% ball `by-pass, the upper limit of total balls to shale is increased from lapproximately 3:1 to 6:1.

The amount of ball temperature increase produced by the utilization of the by-pass featu-re to its fullest extent is approximately 150 F. Thus, the temperature range of the balls entering the cracking zone 30 of FIGURE l can vary from a low of about 850 F., to a high of about 1200 F.

In order to increase the average inlet temperature of the balls entering the cracking zone 30, by approximately 100 F., for example, from the high of 1050 F., previously described with a zero by-pass, to a high of about 1150 F., the total number of balls is iirst heated in zone 24 to a temperature approximately equal to l400 F., by contacting extremely hot gases and =ash at about l600 F., with the balls. The balls leave zone 24, via line 25, and are split into two streams, one being sent, via line 26, into the pyrolyzing zone 20, and the other being sent, via line 27, into line 32, and thence into the cracking zone 30. A ball-oil shale ratio of 1.4:1 is maintained in the pyrolysis zone 20 and the balls leave the pyrolyzing zone 20 at a temperature of 1050 F. Approximately 30% of the total balls in the system enter the line 32 at a temperature of 1400" F., and are admixed with the 1050 F., balls in line 32, or in a suitable mixing apparatus (not shown) placed in line 32. The combined ball stream, entering cracking zone 30, via line 32, has an average uniform temperature of approximately l150 F.

The variation in the amount of by-pass of balls, via line 27, is accomplished by conventional valve control means (not shown) placed in line 25. The valve control means is operatively controlled by the average ternperature desired in the bal-l stream las it enters the cracking zone 30.

As the temperature of the balls entering the cracking zone 30 increases, it is usually found that the period of cracking required decreases. Thus, las the temperature of the balls entering the cracking zone 3) increases from 1050 F., to 1150 F., the time of cracking may decrease from about 60 seconds to about 20 seconds, thus reducing the viscosity of the oil.

If a thermal cracking at still higher temperatures than previously described with reference to FIGURE 1 is desired, such a cracking step is Iaccomplished at the desired high temperatures without losing any of the advantages described with reference to FIGURE 1. Such a high temperature cracking process is described in detail in FIGURE 2.

In FIGURE 2, balls used for the preheating of oil shale in preheating zone 10a are sent to a ball heating zone 24a, of the type previously described in FIGURE 1, and after being heated to temperatures of between l150 and 1500 F., by the products of combustion, are sent directly, via line 50a, to the cracking zone 30a. The extremely hot balls crack the oil vapors and gases entering the cracking zone 30a via line 28a, the balls, vapors and gases contacting each other either in coliow, counterow, cross-flow or other suitable manner.

It will be noted that the oil vapors and gases are cracked lby contact with balls having a substantially higher upper temperature than those preferably employed in the cracking zone 30 of FIGURE 1. (The temperature of the balls entering the cracking zone 30 varied from 850 F. to 1200 F.) Because the cracking in zone 30 occurs at such a high temperature, the period of contact between the balls and oil vapors and gases is preferably extremely short, e.g., usually ranging between 1.0 second and 20 seconds thus reducing the viscosity of the oil. The oil vapor and gas eiuent leaves zone 30a at a temperature of 950 to 1400 F., via line 34a, and must be cooled immediately to 900 F., or lower, to prevent further cracklng.

The balls, after imparting their heat for the cracking step, have a temperature of about l000 to 1400" F., dropping about 50 to 200 F., in passing through the cracking zone 30a. The balls are then sent directly to the pyrolyzing zone 20a, via line 52a. The balls have coke and tar deposited thereon during the cracking process, as previously described. Practically all of the coke and tars are transferred to the incoming preheated oil shale, and upon pyrolysis of the oil shale, is carried with the carbonaceous shale residue via line 38a to combusting zone 40a.

As mentioned previously, a small amount of cracking takes place in the pyrolysis zone 20 of FIGURE 1, and this is true also of the process of FIGURE 2. During the cracking in the pyrolysis zone 20 or 20a, some of the coke and non-volatile tars produced are found to be deposited on the balls inasmuch as some cracking takes place on the balls which are the hottest surfaces in either of the pyrolyzing zones.

The balls, and the coke and non-volatile tars thus deposited thereon are then transferred to the fresh, incoming oil shale, the balls and fresh oil shale preferably being admixed in parallel ow. The fresh oil shale acts to clean or scour the balls of the remainder of the deposited coke and non-volatile tars, as previously described with reference to FIGURE 1. The coke and non-volatile tars eventually are sent to the combusting zone 40o with the carbonaceous shale residue, as just described.

It is thus seen that difficulties inherent in the coking phase of the process, due to the production of coke in the cracking chamber or zone 30a, are effectively minimized by the provision of the circulating heat-carrying bodies or balls. These balls directly contact the oil vapors and gases during the cracking phase of the process to thereby pick up coke and tars produced in the cracking, and at some other point in the process are admixed and agitated with oil shale. In this manner, substantially all the coke and tars are removed from the cracking zone 30a and are transferred to the oil shale. Any coke and tars produced during pyrolysis are also effectively removed from the system. Also, the bulk of the dust entrained from the pyrolyzing zone 20a, along with the oil vapors and gases, is effectively removed from these oil vapors and gases in the cracking zone 30a by means of contact with the ball stream moving through the cracking zone. The dust is carried with the balls, via line 52a, into the pyrolyzing zone 20a. It is thus seen that dust removal from the oil vapors and gases is accomplished without the need for additional equipment.

The remaining lines and zones of FIGURE 2 have been designated by the numerals which correspond to the numerals aifixed to the corresponding lines and zones of FIGURE l, the numerals of FIGURE 2 also having the letter a added thereto. For example, the combusting Zone of FIGURE 2 is designated 40a, while the combusting zone of FIGURE 1 is designated by the numeral 40. The temperature ranges of the materials flowing along these remaining lines and in the zones correspond to those of FIGURE 1 in which there is no flow of balls along by-pass line 27.

It can thus be seen that the main difference between the continuous processes of FIGURES l and 2 is that the process of FIGURE 2 enables a high temperature cracking to take place, whereas the process of FIGURE l enables a lower temperature thermal cracking to occur. 'Ihe temperature of the incoming cracking balls is thus seen to extend over a range of from about 850 F. to 1050 F. (FIGURE 1 with zero by-pass), and from about 1050 F. to 1200 F. (FIGURE l with by-pass) and from about 1150 F. to 1500 F. (FIGURE 2), the total cracking temperature range thus lying between about 850 F. and

9 1500 F. The temperature of cracking employed depends to a great extent on the type of stock being processed, as well as the products desired, and other factors. For example, if cracking takes place at the higher temperatures, more gas, unsaturated hydrocarbons, and aromatic hydrocarbons and less saturated hydrocarbons are produced.

The ball to shale ratio can be varied in the process described in FIGURES l and 2. A ratio of 1.4:1 is presently preferred, although ratios of from 3:1 to 1:1 have also been advantageously employed, depending on the ball temperature entering the pyrolyzing zones 20 or 20a, and the degree of preheat supplied to the oil shale.

A specific example of the process described in FIGURE 2 follows: 1 ton of 25 gallon per ton oil shale enters the preheating zone a along the line 12a and is then admixed with 1.3 tons of balls having an inlet temperature of 800 F. to 900 F. Approximately 2 pounds of water vapor (for a particular Colorado oil shale) leaves along the line 16a. The preheated oil shale leaves the preheating zone 10a along the line 18a to be sent to the pyrolyzing zone 20a. The oil shale now has a temperature of about 505 F.

The balls leave the preheating zone 10a via the line 22a at a temperature of about 600 F., and are sent to the ball heating zone 24a where they are reheated by means of hot combusted gas and shale ash entering the ball heating zone along the line 42a. The gases and ash have a temperature of 1450 F. and heat the balls to a temperature of l350 F. The exhaust gases and ash, leaving the ball heating zone 24a, along the line 46a, have a temperature of about 700 F. The reheated balls are led from the ball heating zone 24a, along the line 50a, to the cracking zone 30a for the cracking of oil vapors and gases coming from the pyrolyzing zone 20a via line 28a.

The oil vapors and gases enter the cracking zone 30a at a temperature of 850 F., and contact the 1350 F. balls for a period of live seconds. The cracked oil vapors and gases leave the cracking zone 30a along the line 34a at a temperature of 1150" F., and -are quenched immediately to a temperature below 800 F., to avoid any fur ther cracking.

The balls, in effecting the cracking of the oil vapors and gases, are reduced in temperature by approximately 100 F. They are sent then to the pyrolyzing zone along the line 52a at a temperature of l250 F.

The l250 F. ba-lls are admixed with the 505 F. oil shale in the pyrolyzing zone 20a thereby producing approximately 225 pounds of oil vapors and gases. These oil vapors and gases are sent to the cracking zone 30a and are cracked as just described.

Approximately 1773 pounds of carbonaceous shale residue are also produced during the pyrolysis in zone 20a and -leave the pyrolyzing zone via line 38a, along with some of the coke and tars that originally were deposited on the balls in the cracking zone 30a. The carbonace'ous shale residue, coke and non-volatile tars are combusted in zone 40a and their products of combustion leave the combustion zone via 42a, at a temperature of 1450" F., to reheat the balls 24a, as above described.

The balls leaving the pyrolyzing zone 20a, via the line 54a, have a temperature of about 960 F. They are sent directly to the heating zone 10a to be admixed with fresh incoming oil shale, to thereby preheat the oil shale to 505 F., as described. The fresh oil shale also scours the balls of coke and tars deposited in the pyrolyzing zone 20a, `due to any cracking that occurs therein.

It will be noted that, while the ball and oil shale vstreams flow parallel to each other in the preheating step and in the pyrolyzing step, the preheating -step and the pyrolyzing step lie in series with respect to one another in the embodiments of FIGURES l and 2. Other arrangements are possible and have been employed. For example, two rotat ing drums, instead of being employed in series, may each be employed as a pyrolyzing drum. No preheating drum is used in this embodiment of the process.

Fresh oil shale was introduced into each of the pyrolyz'- ing drums placed in tandem or in parallel. Heated balls were also introduced and the oil vapors and gases p-roduced in each pyrolyzing drum were sent to a common cracking zone. The balls from each pyrolyzing zone were reheated and Sent to the cracking zone and eected the cracking of the oil vapors and gases therein. The balls, together with the coke and tar deposited thereon in the cracking zone, were then recycled to the parallel pyrolyzing steps where they -contacted fresh oil shale in each of the pyrolyzing drums. The fresh oil shale removed the coke and tar as described previously, and the more volatile tars were volatilized in the pyrolysis zones. The carbonaceous shale residue is removed from the pyrolyzing zone -along with the coke and non-volatile tars that were initially deposited upon the incoming balls, the coke, carbonaceous shale residue and the non-volatile tars being combusted to furnish heat for the reheating of the balls. The reheating of the balls can take place just prior to the pyrolysis rather than after, as just described.

While the process just described is useful, the processes of FIGURES l and 2 are preferable for a number of reasons set forth below.

In the preferred embodiments, FIGURES l and 2, most types of oil shale are preheated to between 400 and 600 F., in a drum or zone separate from that of the pyrolyzing zone. It is found that the number of heat-carrying bodies or balls required for bringing the oil shale to the desired pyrolyzing temperature is substantially reduced when employing a separate preheating step in comparsion to a proc* ess wherein the oil shale is both preheated and pyrolyzed `in a single zone, for the balls may be cooled through a greater temperature range during a given cycle in the process.

Also, at temperatures of between 400 and 600 F., it is found that a portion of the water of crystallization, as well as substantially all of the free moisture in the oil shale, is vaporized and leaves the pyrolysis zone 10 via line 16. It is advantageous to rid the oil shale of as much water as possible in a separate zone prior to the pyrolyzation step, so that the amount of water vapor passing out with the oil vapors and gases during pyrolysis is minimized. The amount of water vapor that is driven olf during the preheating is estimated to be approximately 10% or more of the total free water and water of crystallization present in the oil shale.

The amount of water of crystallization in oil shale varies considerably depending upon the origin and -location of the shale. For example, Brazilian oil shale is found to contain a much greater amount of water of crystallization than Colorado oil shale, and the aforementioned preheating step is especially advantageous when treating the Brazilian oil shale.

Further, the balls should be cleaned of coke and tars before they are sent to the

ball heating zone

24 or 24a in order that the heat transferred to the balls be maximized. Coke and tars deposited on the balls are good insulators and would detriment-ally affect the transfer of heat to the balls if they were retained thereon. Also, the heat of combustion of the coke and tars deposited on the balls appears to be somewhat more elciently transferred to the balls if the coke and tars are rubbed off and eventually burned in the combustion zone 40 or 40a, than if they yare left on the balls and burned in the

ball heating zone

24 or 24a. The advantage of both FIGURES l and 2 over a process wherein the pyrolyzing drums are in parallel, with the cracking taking place after pyrolysis, is that in FIGURES l or 2, the balls are cleaned of coke and tars prior to their entry into the

ball heating zone

24 or 24a (by first passing through preheating zone 10 o-r 10a respectively); in the parallel drum process, such cleaning 'cannot take place because the balls go directly from the cracking zone or pyrolysis zone to the ball heating zone.

Still further, in the parallel process, with cracking taking place after the pyrolysis, the volatile or pyrolyzable l 1 tars are burned rather than recovered in the oil vapors and gases, as in the processes of FIGURES l and 2. Inasmuch as these tars generally contain valuable chemicals, it is economically wasteful to utilize them merely for their fuel value.

Turning now to FIGURE 3, a modied form of process is shown wherein an oil shale preheating step is eliminated, and fresh oil shale is sent directly into a pyrolysis zone 109. Other refinements and Variations of the process are also shown and described.

Referring now to FIGURE 3, in detail, crushed oil shale at ambient temperature, enters the pyrolysis zone or drum 100 along the conduit 102. The oil shale may be preheated to approximately 300 F., by means of Waste hot stack gases emanating from the cyclone 104 if desired.

In the pyrolysis zone 100, the oil shale is intermixed with larger-sized hot balls, coming directly from the cracking zone 8, via line 110, and having a temperature of l050 to l450 F. The intermixing and pyrolysis is accomplished with the ball and oil shale feed running concurrently in the drum 100.

The oil and gas vapors produced in the pyrolysis zone 100 (which may be of a rotary drum or other suitable type) leave via line 110 at a temperature of 750 to 950 F. and pass countercurrently to the incoming balls and upwardly into the cracking zone 108, where the oil vapors and gases meet a continuous hot ball stream, which has an inlet temperature of between ll50 and 1500" F., the exact temperature employed depending on a number of factors, as has been previously mentioned.

The oil and gas vapors are thus cracked in the vapor phase, and without intervening condensation, in the presence of the hot ball stream, for a predetermined time, from 1.0 second to 60 seconds. The cracked oil vapors and gases, having a temperature of 900 to l200 F., are immediately led to a condenser 111 via the line 112, and are immediately cooled below approximately 800 F. to prevent further cracking.

The condensable oils leave via line 113, and the noncondensable gases via line 114.

Coke and tar are deposited on the balls in the cracking zone 108, as previously described with reference to FIG- URES l and 2, thereby avoiding clogging of the cracking equipment and overheating.

The coke and tars are rubbed or wiped off the balls by the action of the fresh oil shale in the pyrolysis zone 100. Here, it will be noted that the balls are cleaned in the pyrolyzing zone 100` rather than in a preheating zone 30. However, the removal of the coke and tars is still accomplished by means of oil shale. Upon pyrolysis of the oil shale and the volatile tars, the resulting carbonaceous shale residue, coke and non-volatile tars leave the pyrolysis zone 100, at a temperature of between 750 to 950 F., passing into separating zone 116.

The smaller-sized carbonaceous shale residue, coke and tars pass through the openings 118 of screen 119 While the larger-sized balls having a temperature of between 850 and 1100 F., pass fro-m the separating unit or zone 116 directly into a conduit 124, where they are elevated to a ball-heating zone 1246.

Gas locks 160, 162 of conventional type are interposed at the top of cracking zone 108 and adjacent the separating unit 116, respectively.

The carbonaceous shale residue, coke and tars pass from zone 116 into line 122 and thence into a fluidized combustion Zone 130, the air for combustion of the carbonaceous shale residue entering along the line 132. The air is preheated, as will be described, and allows recovery of heat in the stack gases otherwise lost.

The combustion step is preferably, but not necessarily, conducted in a iluidized state. Other'suitable combustion processes, such as combustion in a packed bed or rotating bed of carbonaceous shale residue, can also be employed. The fluidized combustion step is preferable, however, inasmuch as the hard and wear-resistant balls grind the shale coke to a considerable degree in the pyrolysis zone 100. The amount of grinding occurring is usually suicient to render the carbonaceous shale residue of a readily fluidizable size.

In order to readily control the temperature within the combustion zone 130, and also to eiTect a greater heat economy, water or air is introduced into a pipe 134, and is passed through coils 133 in the zone 130, the amount of water or air introduced dictating the amount of temperature lowering elected. Steam or preheated air leaves zone via line 136 to be used elsewhere in the process or for other purposes.

The combusted gases produced in zone 130 leave the uidized zone 130 at a temperature of 1250" to 1600 F., along two

conduits

138 and 140. Inasmuch as conduit 138 extends into the iluidized bed 142, the bulk of the hot ash produced in the zone 130 will be entrained, via conduit 138, within the hot combusted gases to the ball heating zone 126.

The remainder of the hot combusted gases pass upwardly through conduit 140, and pass through downwardly moving hot balls in a hot ball inlet chamber 144 and hot ball outlet passage 146 communicating therewith. In this manner, substantially all the shale ash entering the inlet chamber 1414 with the balls is blown back into the ball heating zone 126.

It will be recalled that the balls enter the zone 126 from the line 124, the balls coming directly from pyrolysis zone 100 at a temperature of between 850 to 1100 F. The balls preferably enter the top of the ball heating zone 126, which, in some instances, may merely be an upper section of a combustion zone, and move downwardly countercurrently to the upwardly moving hot gases and entrained ash. Coflow of balls, gases and ash or other suitable methods of direct contact can also be employed. The heated balls are directed into outlet passage 146 by means of an inclined screen 150, and thence flow into the cracking zone 108, at a temperature of ll50 to l500 F., for the cracking of oil vapors and gases, as described.

The `combusted gases and ashes, after passing through the ball heating zone 126, pass through overhead conduit 152 at a temperature of between 900 to l400 F., thence into a heat exchanger 154 where air, at ambient temperature, enters heat exchanger 154 along line 156 to be preheated, for the combustion, to a temperature of between 500 and l200 F. The preheated air passes along line 132 to the combustion zone 130, as previously described.

The combusted gases and the ash, after having passed through heat exchanger 154, pass along conduit 157 at a temperature of 500 to 1200 F., and are separated in one or more cyclones, the stack gas leaving along line 106, and the ash along line 160. The stack gas, having a 600 to 800 F. temperature, can be used to preheat the fresh oil shale, as noted previously.

A ball bleed-olf line and a fresh ball inlet line 172 are also provided leaving and entering the ball elevator line 124, respectively. The ball-shale ratio can be varied within the same limits described with respect to FIGURES 1 and 2.

A specific example of -the process shown and described with reference to FIGURE 3 follows: One ton of fresh 25 gallon per ton oil shale enters the pyrolysis zone 100 along the line 102, at ambient temperatures, and contacts hot balls entering the pyrolysis zone 100 from the line 110, the balls having a temperature of 1350 F., and a flow rate adjusted to give a ball to shale ratio of approximately 2.3:1.

The balls come into the pyrolysis zone 100 directly from the cracking zone 108 and have approximately 6 pounds of coke and tars deposited thereon which are scrubbed off by the fresh oil shale in the pyrolysis zone 100, in the manner described previously with reference to FIGURE 1.

The inlet oil shale size in minus one-quarter mesh,

whereas the ball diameter is approximately Vs inch. During the pyrolysis in the pyrolysis zone, the average size of `the oil shale is substantially reduced, approximately 75 percent of the oil shale having an outlet mesh size of less than l mesh. While such a reduction in size inevitably produces a larger amount of dust, this dust is not sent to the cracking zone along with the oil vapors and gases because it is caught by the balls and carried downwardly with the balls into the pyrolysis zone 100. An efficient dust removal system is thus incorporated into the process as an integral part thereof without the need forl the usual dust -removal equipment.

Approximately 200 pounds of o il vapors and gases, and volatile tars produced during the pyrolysis are sent to the cracking zone 103 for the cracking thereof, as will be described. Approximately 1810 'pounds of carbonaceous shale residue, coke and non-volatile tars are separated from the balls in unit 116 and arev sent to a combustion zone 1730 via the line 122, the carbonaceous shale residue, coke and tars having an inlettemperature of 850 F. The total amount of free combustible carbon thus sent to the combustion zone 130 is approximately 56 pounds.

Airenter's the combustion zone along the line 132 at a temperature of 530 F. with a sutlicient velocity to tluitliae theresidues in zone 130 and combustion takes place so that the outlet gases and ash have a temperature 'of l400 F. Water or air enters the conduit 134, passes through the coils 133 within the Combustion zone and leaves as steam or preheated air along line 136. In this manner, the combustion within the combustion zone is controlled so that the outlet temperature of the comb'ustion products is maintained within relatively close limits. The bulk of the shale ash produced during the combustion leaves along the line 138 with the majority of the hot combustion gases and passes through a downwardly moving packed bed of balls in the ball heating zone 126. The remainder of the hot gases passes upwardly through linep140 for a purpose to be described.

It will be recalled that the balls separated from the earbona'ceous shale residue, coke and tar within separating unit 116 pas'slthrough the ball elevator line 124, at a temperature of 900 F. and enter the ball heating zone 126. The balls are thus reheated by means of the hot combusted gases and the shale ash to a temperature of 1375 F. The hot ash and gases, leaving the ball heating zone 12o via ythe line 152, have a temperature of 950 F. and are sent to a heat exchanger 154 where they preheat air to a temperature of 530 F. The preheated air is sent Via line 132 to the combustion zone 130 for the combustion of carb'onaceous material as previously described.

The reheated balls, having va temperature of 1375" F. pass into conduit 146 and into ball inlet chamber 144. The balls carry with them the hot ash previously sent to the ball heating zone 125 via the line 138. The hot combusted gases entering the chamber 144 from the line -140 remove or sweep the ash from the balls and from the chamber. the cracking zone 108, contacting vapors at 850 F. l'entering the 'cracking zone via line 110. Cracking is eiiected over a period of time of l5 seconds.

The `cracked oil vapors and gases leave the cracking zone 108 along the line 112 to be immediately quenched in the condenser 111. The cracked oil vapors and gases have a temperature of 1175 F. prior to the quenching -and are quenched to at least 800 F. so that further The hot balls, at l375 F. then enter l It will thus be seen that a highly efficient process is provided for the pyrolyzing and cracking of oil shale and the like, in that the condensing and reheating of the oill and gas vapors prior to cracking is eliminated.

Furthermore, the coke and t'ar deposited on the balls in the cracking zone 108 eliminates the possibility of clogging and overheating of the cracking equipment. The coke and tars arey carried out with the ball stream, through the pyrolysis drum 100, and eventually the coke and the non-volatile tars pass through the combustion zone with the carbonaceous shale residue. The coke andr non-volatile tars thereby furnish additional heat for the process in a simple, continuous and troublefreemanner.

Also, dust problems in the oil vapors and gases are greatly reduced, inasmuch as the bulk of the dust entrained from the pyrolysis dru'm 100 by means of the oil vapors and gases is led back by the ball stream to re-enter the pyrolysis drum via conduit 110.

It will be seen that a plurality of separate and distinct non-intermingling ball 'circiuts can be utilized, if desired. For example, a separate ball vcircuit between the pyrolyzing zone, ball heater and 'oil shale preheating zone, and a second circuit between the cracking zone and a separate ball heater can be employed.

Also, it will be understood that portions of the reheated or relatively cool ball streams could be utilized for preheating air 'for' combustion purposes, preheating water for steam, as well as the other uses previously described.

It should b'e noted that the temperature of the oil vapor 'and gas efuent from the cracking

zones

30, 30a and 108 of FIGURES 1, 2 and 3, respectively, can readily be varied between about 825 F. and 140() F.

Attention is also drawn to the fact that in some instances, all or part of theheat required for heating the balls in any of the embodiments of my process may be furnished from sources extraneous to the process, or by means of the products of pyrolysis other than the carbonaceous shale residues, e.g., the combustible gases.

While several embodiments of my invention have been disclosed herein, it will be understood that modifications and changes may be made herein that lie within the ordina'ry skill of those in the art. For this reason, I do not intend to be bound by the embodiments `herein shown and described, but intend to be bound only by my claims which follow.

-I claim: v

1. The process of obtaining oil 'and gas, from solid material leaving, upon pyrolysis, a solid carbo'naceous residue, which comprises the steps of: pyrolyzing said solid material by` solid-to-solid milling contact with solid heat-carrying bodies to obtain oil vapors and gases, and a Asolid carbo'naceous residue; separating said heat-carrying bodies yfrom said solid carbonaceous residue, produced upon the pyrolysis of said solid material; thermally cracking, in a separate zone, said oil vapors and gases by admixtnre with said separated lsolid heat-carrying bodies to obtain cracked oil vapors and gases; combusting said solid carbonaceous residue to thereby produce heat in the form of gaseous and solid products; reheating the solid heat-carrying bodies yby means of at least one of said .products of combustion;v and recycling said heated heatcarrying bodies for admixture with additional solid material for the pyrolysis thereof, and for the cracking of oily vapors and gases produced during said pyrolysis.

2. The process of claim 1 wherein said solid material and the heat-carrying bodies are admixed in parallel flow during pyrolysis.

3. The lprocess of claim 1 wherein said solid material is oil shale. K

`4. The process of claim l wherein said solid material -iis oil shale and the temperature of said solid heat-carrying bodies employed for the cracking of said oil vapors and gases lies between 850 F. and 1500 F.

5. The process of claim 1 wherein said solid carbonaceous residue is iluidized and the combustion thereof takes place in a iluidized state.

6. The process of claim 1 wherein coke and tars produced during said cracking are deposited on said heatcarrying bodies which furnish the heat for said cracking, said coke and non-volatile component of the tars being later combusted, along with said carbonaceous residue, to furnish additional heat to the process.

7. The process of claim 1 wherein oil vapors and gases, and entrained dust therein, are passed through said separated heat-carrying bodies, a substantial amount of said entrained dust being collected on said bodies.

8. The process of claim 1 wherein said heat-carrying bodies employed in the pyrolyzing and cracking steps are intermixed with fresh solid material in a separate zone to thereby preheat said solid material, to a temperature of below 700 F., prior to its pyrolysis.

9. The process of obtaining oil and gas from solid material, leaving, upon pyrolysis, a solid carbonaceous residue, which comprises: pyrolyzing said solid material by solid-to-solid milling contact with hot, solid heatcarrying bodies larger than said carbonaceous residue to produce an oil vapor and gas effluent and a solid carbonaceous residue; separating said heat-carrying bodies from said solid carbonaceous residue, produced upon the pyrolysis of said solid material; thermally cracking,in a separate zone, said oil vapor and gas eiliuent by means of said heat-carrying bodies in the absence of said carbonaceous residue to produce a cracked oil vapor and gas eiuent, said heat-carrying bodies having a substantially dilierent initial temperature for the cracking than for the pyrolysis; combusting said separated carbonaceous residue in the presence of an oxygen-containing gas to thereby produce heat in the form of hot gaseous and solid products; reheating said heat-carrying bodies employed in the pyrolysis and cracking steps by means of at least one of said products of combustion; and recirculating said reheated heat-carrying bodies for admixture with additional solid material and resulting oil vapors and gases for said pyrolysis and cracking steps.

l0. The process of claim 9 wherein the initial temperature of said heat-carrying bodies immediately prior to the cracking, is higher than the initial temperature of said heat-carrying bodies immediately prior to the pyrolysis.

11. The process of claim 9 wherein the initial temperature of said heat-carrying bodies immediately prior to the cracking, is lower than the initial temperature of said heat-carrying bodies immediately prior to the pyrolysis,

12. The process of claim 9 wherein the temperature of said oil vapor and gas eflluent from the pyrolysis lies between 750 to 950 F. and the temperature of said cracked oil vapor and gas eluent from the cracking lies between 825 and l400 F.

l13. A continuous process for obtaining oil and gas from solid material, leaving upon pyrolysis, a solid carbonaceous residue, which comprises: pyrolyzing said solid material, by solid-to-solid milling contact with hot heat-carrying bodies larger than said solid carbonaceous residue, to produce oil vapors and gases and solid carbonaceous residue, the heat-carrying bodies being partially cooled thereby; separating said heat-carrying bodies from said solid carbonaceous residue, produced upon the pyrolysis of said solid material; thermally cracking, in a zone separated from said solid material and said solid carbonaceous residue, said oil vapors and gases, prior to the condensation thereof, in the presence of said separated partially cooled heat-carrying bodies employed in the pyrolysis to produce thereby still cooler heat-carrying bodies; combusting said solid carbonaceous residue in the presence of a free oxygen-containing gas to thereby produce heat in the form of hot gaseous and solid products; reheating said cooler heat-carrying bodies by means of at least one of said products of combustion; and recycling said reheated heat-carrying bodies for admixture with additional solid material and resulting oil vapors and gases for said pyrolyzing and cracking steps, said resulting oil vapors and gases being kept separate from said combustion gases.

14. The process of claim 13 wherein the temperature of the oil vapors and gases, immediately after cracking lies between 825 F. and 1000 F., and temperature of oil vapors and gases immediately after pyrolysis lies between 750 F. and 950 F.

l5. The process of claim 13 wherein said solid material is preheated just prior to pyrolysis, the temperature of the solid material after its preheating ranging between 400 to 700 F., the heat for said preheating being furnished by at least a portion of said cooler heat-carrying bodies.

16. The process of claim 13 wherein coke and tars produced during said cracking are deposited on said heatcarrying bodies which furnish heat for said cracking, said coke and the non-volatile component of the tars being later combusted, along with said solid carbonaceous residue, to furnish additional heat to the process.

17. The process of obtaining oil and gas from oil shale which comprises: preheating fresh oil shale in a preheating zone to a temperature of between 400 and 600 F. by solid-to-solid milling contact of said oil shale in parallel flow with partially cool heat-carrying bodies larger than the preheated oil shale, said partially cool bodies having a temperature higher than said fresh oil shale; reheating said partially cool heat-carrying bodies; pyrolyzing said preheated oil shale by solid-to-solid milling contact, in parallel flow, with said reheated heatcarrying bodies, to produce oil vapors and gases having a temperature ranging between 750 and 950 F., and carbonaceous shale residue; separating said heat-carrying bodies from said carbonaceous residue; thermally cracking, in a zone separated from said solid material and said solid carbonaceous residue, said oil vapors and gases, prior to the condensation thereof, in the presence of said separated heat-carrying bodies having an initial temperature of between 850 and 1050 F., coke and tars produced during said cracking being deposited on said separated heat-carrying bodies; returning said heat-carrying bodies from the cracking zone to said preheating zone for the preheating of fresh additional oil shale, thereby partially cooling the heat-carrying bodies and, by contact, transferring the coke and tars from said heat-carrying bodies to said fresh oil shale, the volatilization of the volatile tars, as well as production of said oil vapors and gases, occuring during saidpyrolysis, said coke and the non-volatile component of the tars being carried with said carbonaceous shale residue formed during the pyrolysis; combusting said carbonaceous shale residue, coke and tars in the presence of a free oxygen-containing gas to thereby produce hot gaseous and solid products, said reheating of said partially cool heat-carrying bodies being provided by means of at least one of said products of combustion for the preheating of additional fresh oil shale.

18. The process of obtaining oil and gas from oil shale, leaving upon pyrolysis, a carbonaceous shale residue, which comprises: pyrolyzing preheated oil shale by solidto-solid milling contact thereof with hotter heat-carrying bodies having an initial temperature of between 1000 to 1400 F., to produce oil vapors and gases at a temperature of between 750 and 950 F. and carbonaceous shale residue in a pyrolysis zone; separating said heat-carrying bodies from said carbonaceous shale residue, produced upon the pyrolysis of said oil shale; transferring said heat-carrying bodies employed in the pyrolysis of said preheated oil shale with fresh oil shale to a preheating zone to thereby preheat said oil shale to a temperature of between 400 and 600 Ff., the heat-carrying bodies being partially cooled after said preheating; combusting said carbonaceous shale residue produced during the pyrolysis to produce hot gaseous and solid products; reheating said partially cooled heat-carrying bodies -by means of at least 'one of said products of combustion to a temperature of between 1000 and l400 F.; contacting said reheated heat-carrying bodies with said oil vapors and gases, in 'a zone separate from said pyrolysis Zone, to effect cracking of said oil vapors and gases, the coke and tars produced during' the cracking being deposited on said heat-carrying bodies; adrnixing said heat-carrying bodies employed in the cracking, along with coke and tars produced during lthe cracking, with said preheated oil shale `for the pyrolysis thereof, said coke and tars being removed from the heatcarrying bodies and taken along with said carbonaceous shale residue produced during the pyrolysis to be combusted to furnish additional heat for the process.

19. The process or obtaining oil and gas from o-il shale, leaving upon pyrolysis, a carbonaceous shale residue, which comprises: pyrolyzing oil shale by solid-tosolid milling contact with hotter larger-sized, heat-carrying bodies having aninitial temperature lying between l050 F. and 1450 F., said oil shale and heatecarrying bodiesbeing admixed in parallel now, oil vapors and gases and carbonaceous shale residue being produced during said pyrolysis; separating said heat-carrying bodies from said carbonaceous shale residue; fluidizing said carbonaceous shale residue; combusting said iluidized carbonaceous shale residue to produce gaseous and solid hot products; reheating said heat-carrying bodies by direct contact thereof with at least one of said hot combustion products; contacting said r'eheated heat-carrying bodies with said oil vapors and gases to thereby crack said oil vapors and gases, coke and tars produced during the cracking being deposited on said heat-carrying bodies; and admixing said heat-carrying bodies carrying said coke and tars, with additional oil shale, said coke and tars being removed from said heat-carrying bodies by said additional oil shale, and the coke and tars being carried out with said carbonaceous shale residue produced during the pyrolysis of said oil shale, said coke and nonvolatile tars being combusted with said shale coke to furnish additional heat for the process.

20. The process according to claim 19 wherein said products of combustion include -both hot gaseous products and hot entrained shale ash, said products of combustion being divided into two streams, one stream comprising the bulk of the entrained ash and a substantial amount of the hot gaseous products produced, said one stream being admixed with said heat-carrying bodies forv the reheating of saidl bodies, and the other stream comprising substantially the remainder of the hot gases, being admixed with said heat-carrying bodies after they have been reheated by said one stream, said other stream removing substantially all of the shale ash collected by the heat-carrying bodies..

2l. Apparatus-for continuous recovery of oil from oil shale comprising: a preheating rotary drum having an inlet for fresh oil shale and an outlet for preheated oil shale; a pyrolyzing rotary drum having an inlet for preheated oil shale, an outlet for carbonaceous shale residue and an outlet for oil vapors and gases, said carbonaceous shale residue and said oil vapors and gases resulting from pyrolysis of said preheated oil shale in said pyrolyzing drum; a plurality of solid heat-carrying bodies larger than the preheated oil shale; a heater for heating said bodies; means for moving said carbonaceous shale residue to a combustion zone; means for combusting said carbonaceous shale residue in said combustion zone to provide heat for said heater; means for moving said heatcarrying bodies from said heater into and through said `pyrolyzing drum in parallel flow therethrough with said preheated oil shale, from said pyrolyzing drum into and through said preheating drum in parallel flow therethrough with said fresh oil sha1e,and from said preheating drum into 'and through said heater; means assoeiated with said preheating 4rotary drinn for' separating 'said heat-'carrying bodies from the preheated oil shale; and means associated `with the pyrolyzing rotary drum for separating said heat-carrying bodiesv from said lcarbonaceous shale residue.

22. Apparatus for continuous recovery of oil from oil shale comprising: a preheating rotary drum having an inlet for fresh oil shale and an outlet Ifor preheated oil shale; a pyrolyzing rotary drinn having an inlet for preheated oil shale, an outlet -for carbonaceous shale residue and an outlet for oil vapors and gases, said carbonaceous shale residue and said oil vapors and gases resulting from pyrolysis of said preheated oil shale in said pyrolyzng drum; a plurality of 'solid heat-carrying bodies larger than the preheated oil shale; a heater for heating said bodies, said heater comprising means for cornbusting said carbonaceous shale residue and transferring lthe heat from at least one of the products of 'said cornbustion to said heat-carrying bodies to thereby heat said bodies; means for moving said heat-'carrying'bodies from said heater into and through said pyrolyzing drinn in parallel how therethrough with said preheated oil shale, from said pyrolyzing drum into and through said preheating drum in parallel ow therethrough with said -fr'esli oil shale, and from said preheating drum into and through said heater; means associated with said preheating rotary drum for separating said heat-carrying bodies from the preheated oil shale; means associated with the pyroly'zing rotary drum for separating said heat-carrying bodies from said carbonaceous shale residue; and means for passing said oil vapors and gases from said pyrolyzing drum through a cracking chamber in contact =with said heatcarrying bodies during the passage of said heat-carrying bodies between said heater and said preheating dru'n.

23. Apparatus for continuous recovery 'of oil from oil shale comprising: a preheating rotary drum having 'an inlet for fresh oil shale and an outlet for preheated oil shale; a pyrolyzin'g rotary drum having an inlet for preheated oil shale, an outlet for carbonaceo'us shale residue and an outlet for oil vapors and gases, said carbonace'ous shale residue and said oil vapors and gases resulting from pyrolysis of said preheated oil shale in said pyrolyzing drum; a plurality of solid heat-carrying bodies larger than the preheated oil shale; a heater for heating said bodies; means for moving said heat-carrying bodies from said heater into and through said pyrolyzin'g drum in parallel ow therethrough with said preheated oil shale, from said pyrolyzing drum into and through said preheating drum in parallel ow therethrough with said fresh oil shale, and from said preheating drum into. and through said heater; means associated with said preheating rotary drum for separating said heat-carrying bodies from the preheated oil shale; means associated with the pyrolyzing rotary drum for separating said heat-carrying bodies from said carbonaceous shale residue; and means for passing said oil vapors and gases from said pyrolyzing drum through a cracking chamber in contact with said heatcarrying bodies during the passage of said heat-carrying bodies between said heater and said pyrolyzingl drum.

24. Apparatus for continuous recovery of oil from oil shale comprising: a preheating rotary drum having an inlet for fresh oil shale and an outlet for preheated oil shale; a pyrolyzing rotary drum having an inlet for pre heated oil shale, an outlet for carbouaceous shale residue and an outlet for oil vapors and gases, said carbonaceous shale reside and rsaid oil vapors and gases resulting from pyrolysis of said preheated oil shale in said pyrolyzing drum; `a plurality of solid heat-carrying bodies larger than the preheated oil shale; a heater for heating said bodies; means for moving said heat-carrying bodies from said heater into and through said pyrolyzirig drum in parallel ow therethrough with said preheated oil shale,- from said pyrolyzing drum into and through said preheating drum in parallel ow Itherethrough with said fresh oil shale, and from said preheating drum into and through said heater; means associated with said preheating rotary drum for separating said heat-carrying bodies from the preheated oil shale; means associated with the pyrolyzing rotary drum for separating said heat-carrying bodies from said carbonaceous shale residue; and means for passing said oil vapors and gases from said pyrolyzing drum through a cracking chamber in contact with said heatcarrying bodies during the passage of said heat-carrying bodies between said pyrolyzing drum and said preheating drum.

25. The apparatus of claim 24 wherein means is provided for bypassing some of said heat-carrying bodies around said pyrolyzing drum into said cracking chamber.

26. A plant for the continuous recovery of oil from oil shale comprising: a pyrolyzing rotary drum having an inlet for oil shale, an outlet for carbonaceous shale residue and an outlet for oil vapors and gases, said carbonaceous shale residue and said oil vapors and gases resulting from pyrolysis of said oil shale in said drum; a plurality of heat-carrying bodies larger than the carbonaceouse shale residue; a heater for heating said bodies; means for moving said heat-carrying bodies from said heater into and through said pyrolyzing drum and back to said heater; means associated with said pyrolyzing rotary drum for separating the heat-carrying bodies from the carbonaceous shale residue; and means for passing said oil vapors and gases from said pyrolyzing drum through a cracking chamber in contact with said heat-carrying bodies to thermally crack said oil vapors.

27. A plant for the continuous recovery of oil from oil shale comprising: a pyrolyzing rotary drum having an inlet for oil shale, an outlet for carbonaceous shale residue and an outlet for oil vapors and gases, said carbonaceous shale residue and said oil vapors and gases resulting from pyrolysis of said oil shale in said drum; a plurality of heat-carrying bodies larger than the carbonaceous shale residue; a heater for heating said bodies; means for moving said heat-carrying bodies from said heater, into and through said pyrolyzing drum and a cracking Zone, and back to said heater; means associated with said pyrolyzing rotary drum for separating the heat-carrying bodies from the'carbonaceous shale residue; and means for passing said oil vapors and gases from said pyrolyzing drum through said cracking chamber in contact with said heatcarrying bodies .to thermally crack said oil vapors.

28. A process for the continuous recovery of oil from oil shale which comprises: preheating fresh oil shale to a temperature of between 400 and 700 F. by admixing said oil shale in parallel ow, in solid-to-solid milling contact with solid hotter heat-carrying bodies having a particle size larger than that of the preheated oil shale, said heat-carrying bodies being partially cooled thereby; separating said partially cooled heat-carrying bodies from the preheated oil shale; heating said partially cooled heatcarrying bodies; pyrolyzing said preheated oil shale by admixture in parallel ow, with said heated heat-carrying bodies to lproduce oil vapors and gases, and carbonaceous shale residue; separating said heat-carrying bodies from the car-bonaceous shale residue; thermally cracking a portion of the said oil vapors and gases; and combusting said carbonaceous shale residue to produce hot products of combustion, said products of combustion furnishing the heat for the said heating of said heat-carrying bodies.

29. The process of obtaining oil and gas, from solid material, leaving, upon pyrolysis, a solid carbonaceous residue, which comprises the steps of: pyrolyzing said solid material to produce oil vapors and gases and a solid carbonaceous residue; thermally cracking, in a zone separated from said solid material and said solid carbonaceous residue, said oil vapors and gases, heat for -both pyrolyzing and cracking being provided by admixture of said solid material and said oil vapors and gases, respectively, with solid hot heat-carrying bodies having a particle size larger than the said carbonaceous residue, said heat-carrying bodies and said solid material being in solid-to-solid milling contact during pyrolysis of said solid material and being separated from said solid material and said carbonaceous residue before being contacted with said oil vapors and gases; reheating said solid heat-carrying bodies; and repeating said pyrolyzing and cracking steps by admixture of additional solid material and resulting oil vapors yand gases with said reheated solid heat-carrying bodies.

30. The process of obtaining oil and gas, from solid material, leaving, upon pyrolysis, a solid carbonaceous residue, which comprises the steps of: pyrolyzing said solid material to produce oil vapors and gases and a solid carbonaceous residue; thermally cracking said oil vapors and gases, in a zone separated from said solid material and said solid carbonaceous residue, heat for both pyrolyzing and cracking being provided by admixture of said solid material and said oil vapors and gases, respectively, with solid heat-carrying bodies, said heatcarrying bodies being larger than said carbonaceous residue; separating said solid heat-carrying bodies from said carbonaceous residue; reheating said solid heat-carrying bodies; at least part of the heat being furnished by means of at least one of the products of combustion of the said carbonaceous residue; and repeating said pyrolyzing and cracking steps by admixture of additional solid material and resulting oil vapors and gases with said reheated soild heat-carrying bodies, said heat-carrying bodies and solid material being in solid-to-solid milling contact during pyrolyzing of said solid material.

31. The process of claim 30 wherein said heat-carrying bodies employed in the pyrolyzing and cracking steps are inter-mixed with fresh solid material in a separate zone to thereby preheat said solid material, to a temperature of below 700 F., prior to its pyrolysis.

32. The process of claim 30 wherein only part of all of said reheated heat-carrying bodies contact additional solid material for the pyrolysis thereof.

33. The process of obtaining oil and gas, from solid material leaving, upon pyrolysis, a solid carbonaceous residue, which comprises the steps of: pyrolyzing said solid material by solid-to-solid milling contact with solid heat-carrying bodies larger than the said solid carbonaceous residue to obtain oil vapors and gases, and a solid carbonaceous residue; separating said heat-carrying bodies from said solid carbonaceous residue, producedupon the pyrolysis of said solid material; thermally cracking said oil vapors and gases, in a zone separated from said solid material and said solid carbonaceous residue, by admixture with said separated solid heat-carrying bodies to obtain cracked oil vapors and gases; combusting said solid carbonaceous residue to thereby produce hot gaseous and solid products; reheating all Vof said solid heat-carrying bodies by means of at least one of said products of combustion; and recycling part of said heated heat-carrying bodies -for admixture with additional solid material for the pyrolysis thereof and recycling part of said heatcarrying bodies for the cracking of oil vapors and gases produced during said pyrolysis.

34. The process of claim 33 wherein said heat-carrying bodies employed in the pyrolyzing and cracking steps are intermixed with fresh solid material in a separate zone to thereby preheat said solid material, to a temperature of below 700 F., prior to its pyrolysis.

References Cited in the tile of this patent UNITED STATES PATENTS 1,450,327 Smith Apr. 3, 1923 1,940,955 Laird Dec. 26, 1933 2,027,862 Goodwin et al Jan. 14, 1936 (Other references on following page) 21 UNITED STATES PATENTS Ostergaard Nov. 6, 1945 Dutcher Dec. 5,1950 Rex Aug. 26, 1952 Johnson et al. Nov. 9, 1954 5 22 Jahnig et al. Jan Iahnig et al Jan Burnside et al. Feb

Russell Apr. Krebs et a1 Aug

Claims

1. THE PROCESS OF OBTAINING OIL AND GAS, FROM SOLID MATERIAL LEAVING, UPON PYROLYSIS, A SOLID CARBONACEOUS RESIDUE, WHICH COMPRISES THE STEPS OF: PYROLYZING SAID SOLID MATERIAL BY SOLID-TO-SOLID MILLING CONTACT WITH SOLID HEAT-CARRYING BODIES TO OBTAIN OIL VAPORS AND GASES, AND A SOLID CARBONACEOUS RESIDUE, SEPARATING SAID HEAT-CARRYING BODIES FROM SAID SOLID CARBONACEOUS RESIDUE, PRODUCED UPON THE PYROLYSIS OF SAID SOLID MATERIAL, THERMALLY CRACKING, IN A SEPARATE ZONE, SAID OIL VAPORS AND GASES BY ADMIXTURE WITH SAID SEPARATED SOLID HEAT-CARRYING BODIES TO OBTAIN CRACKED OIL VAPORS AND GASES, COMBUSTING SAID SOLID CARBONACEOUS RESIDUE TO THEREBY PRODUCE HEAT IN THE FORM OF GASEOUS AND SOLID PRODUCTS, REHEATING THE SOLID HEAT-CARRYING BODIES BY MEANS OF AT LEAST ONE OF SAID PRODUCTS OF COMBUSTION, AND RECYCLING SAID HEATED HEATCARRYING BODIES FOR ADMIXTURE WITH ADDITIONAL SOLID MATERIAL FOR THE PYROLYSIS THEREOF, AND FOR THE CRACKING OF OIL VAPORS AND GASES PRODUCED DURING SAID PYROLYSIS.