Extraction of organic materials from Green River, Wyoming oil shale by Ronald H Johnson A THESIS Submitted to the Graduate Faculty in partial fulfillment of the requirements for the degree of Master of Science in Chemical Engineering Montana State University © Copyright by Ronald H Johnson (1961) Abstract: This investigation is a continuation of a study being made at Montana State College on the air-oxidation and. recovery of the organic material contained .in. Westvaco's • Green- River, Wyoming .oil -shale. The: study also has as one .of its goals the identification of the oxidized .organic components. A stainless steel fluid-bed reactor was used, for the. air-oxidation of the organic material. .The,oxidized organics were then extracted from the oil shale by boiling a water-shale mixture at atmospheric pressure under total reflux. The study was made to determine the optimum, condition for the air-oxidation of oil shale in a fluid-bed .reactor. The first set of experimental runs was made to study the effect of temperature, pressure., and ,time on the yield obtained while using a shale size distribution of. -12, +100 mesh. A maximum yield of 11.17 per cent was obtained when the oil .shale was oxidized at 240°C and 40.2 pounds per square inch absolute pressure for seven hours. The air velocity through the reactor remained at 0,.55 feet per second for the entire study. In an effort to shorten the oxidation time, a second study was made using a shale size distribution of -55, +150 mesh. In this study, a yield of 9.77 Per cent was reported when the shale was oxidized at 240°C ,and 40.2 pounds per square inch absolute for five hours. ¦ This was selected as the optimum operating condition for this investigation because of the shorter oxidation time. It was found that a particle size distribution was needed fo obtain, desirable yields. From a charge haying a size - distribution of -35, + 150 mesh and specific surface of 322 cm^2 per gram of shale, a. yield of 9.77 per cent was obtained and from a similar charge of a single screen size (-.65, +100 mesh) .and a. specific surface of 315 cm^2 per gram, a yield of only 5.6 per cent was obtained. The identification study shows the .oxidation products, to .be -essentially highly complex acid polymers. Another result of this part of the study shows that the acid soluble portion of the product and an .acetone extract of the acid insoluble portion have the same structural groups present.  fEXTRACTION. OF ORGANIC .MATERIALS.FROM GREEN.RIVER^.WYOMING,OIL SHALE by RONALD- H. JOHNSON A THESIS Submitted to the Graduate-Faculty in- partial fulfillment o£ the requirements for-the .degree of Master of. Science in Chemical Engineering. ..at Montana State College Approved: Heady. Major Departm^rftf Chairman- -Exaininihg ,Committee D e a n GradUat .vision 'Bpzemany Montana June, 196,1 fills f - 2 - TABLE OF CONTENTS Page Abstract ............................................................... 3 Introduction ....................... A. Oil Bearing Shales . . . . B. Purpose of this Investigation Procedure, Equipment, and Materials ............................. 7 A. Procedure and Equipment ..................................... 7 1. Preparation of the F e e d ..................................7 2. Fluid-Bed Air-Oxidation .............................. 7 3. Extraction................................................. 15 4. Identification of the Organic Constituents . . . . 17 5- Simultaneous Air-Oxidation and Extraction 18 6. Large Quantity Air-Oxidation and Extraction . . . 18 B. M a t e r i a l s .....................................................19 Discussion of Results ............................................... 20 A. A i r - O x i d a t i o n ................................................. 20 B. Extraction of the Organic M a t e r i a l ..........................28 C. Identification of Organic Material ....................... 29 D . Simultaneous Air-Oxidation and Extraction ................. 30 S u m m a r y ............................................................... ... Recommendations........................................................34 Bibliography ......................................................... 35 Acknowledgment ......................................................... 36 Appendix ...............................................................37 vn f f r ~ 3 - ABSTRACT This -investigation. is. a c0n.tinu9.ti0n of a, study being made at Montana State College on the ^air-oxidation and. recovery of the organic material contained :in. Westyaco.!s ■ Green-River, Wyoming .oil-shale. The: study also has as one .of its goals the identification of the oxidized .organic components. A stainless steel fluid-bed reactor was used.for the.air-oxidation .of the.organic material. .The.oxidized organics were then extracted.from the .oil shale by boiling a water-shale mixture s.t atmospheric pressure under total reflux. The study was made to.determine the optimum, condition fof.the air- oxidatipn of.oil shale in a fluidrbed.reactor. • The first set of experi­ mental, runs was made to study the effect of temperature, pressure.,-and ,time on the. yield.obtained .while using, a shale size distribution of. -12, +100 mesh. A maximum, yield .of 11.17 per cent was. obtained when .the oil .shale was oxidized at 'Z^O0C and 40.2 pounds per square inch absolute pressure for seven hours. The air.velocity through the reactor remained •at 0,.55 feet per second for.the entire study. In an effort to shorten the oxidation time,-a second., study was made UtSing a.shale size distribution of -35, +150 mqah. In this study, a yield of .9.77,per cent was reported when the shale was oxidized- at 240'°C ,and 40.2 pounds, per -square inch absolute for fiye hours.. ■ This was selected as the optimum-operating condition for this investigation because of the shorter.oxidation time. ■It was found that a particle size distribution was needed fo obtain. desirable yields. From a charge haying a size distribution of -35, +150 mesh and. specific surface .of 322 cm5 per gram of shale, -a. yield of 9.77 per cent was obtained and from a similar charge of a.single screen size (“65» +100 .mesh), and a. specific surface of 315 Pm^ .per gram, a yield of only 5.6 per cent was obtained. The identification study shows the .oxidation products, to .be ■essentially highly, complex acid.polymers. Another result of this part of the study shows that the acid soluble portion of the product and an ■acetone extract of the acid insoluble portion.haye the same structural groups present. - 4 - ■ INTRODUCTION A. Oil Nearing ,Shales The name "oil .shales" has been given to .clayey or sandy deposits from whidh oil may be obtained by distillation and not by treatment with solvents (I).. • Oil shale has a gray to black appearance when it is mined, .due to the amount of kerogen present. Kerogen is the carbonaceous, matter derived frtom plant or animal remains that has been Nepeslted.with-'the shale. Oil can be obtained from the kerogen by destructive -distillation. •Oil from oil shale has the .greatest promise of supplementing the supply, of petroleum than any other source. First,, because it fields products very similar to .those made from petroleum, and second, because of the abundance of oil shale in the United States (I). The largest known deposits of oil .shale are in Colorado, .Utah, Wyoming, and Nevada. These oil shales contain considerable amounts of kerogen and may become • cemmeredally important when the mere easily exploited petroleum-deposits approach, exhaustion. At the present time, it is not economically feasible to.produce oil from the kerogen. contained in the oil shale. Much attention has been given to the aspect of. obtaining organic compounds from.these shales or.from the oil obtained therefrom which might warrant exploiting the oil .shale deposits. -This report is concerned with extraction of organic compounds from -the Green River.Oil Shale Formation at Green River, Wyoming. - 5 - B. Purpose-of. this .Investigation At Green. River, Wyoming,. Westvaco Division of the Food. Machinery and Chemical Corporation has been producing, a high-grade soda ash (sodium, carbonate) from trona. ■ The trona, sodium sesquicarbonate,,is a mineral composed of hydrous sodium carbonate and sodium bicarbonate. The trona is in a bed.several hundred feet below the surface of the earth and is eight to ten feet thick. This trona lies between two lajrers of shale, both of which contain organic material in varying degrees. ■Because .of its close proximity to the shale, the raw trona. also .contains small quantities of organic material which find their way to the processing liquors. Certain investigations made in connection with the problems encountered because of the presence of this organic material led Westvavo.to.consider the feasibility of recovering useful organic materials from the shale deposits. •The work reported in this thesis is a continuation of a study made at Montana State College which was Under­ taken for the purpose of extracting and identifying the organic material from the shale deposits, associated with the Grepn River trona (3. and 4). . Suiter (4) made-a study of oxidizing the organic material by twd methods. Qne was the simultaneous oxidation of the organic,material by potassium permanganate and the extraction of the oxidation products with an alkaline water solution. ■ Re reported that 7Q to .8O per. cent of the available organic-material was removed from .the oil shale -by.using this above method. The removed oxidized material accounted for approximately 6.7 per cent of the shale weight. ■ The other method he used was the air- - 6 - oxidation of the organic.material in the shale.-The oxidation was done by. fluidizing the shale with air in a heated. Byrex glass column. ■ In this pa^t of the-study,, he reported recovering ten to twenty per cent of the available organic material. This part of.his study*,however* was very limited. Erickson (.5) continued the .investigation of the fluid^bed' air- oxidation of the organic.material. • For his investigation, he used a heated stainless steel reactor for the air-oxidation. Only the bottom or lower shale was. Used, in his investigation. He ..reported a maximum/ yield of 10.I) per.cent of the oxidized shale weight. • He also made a study.of. methods and .conditions for .extracting organic material.from oxidized oil shale. In. this.part.of his study, he concluded that boiling a shale-water, mixture at atmospheric pressure under total reflux was the best method considered. The optimum extraction ■condition was boiling the mixture for one hour with a water to shale ratio of,10:1. This investigation is a further study, of the fluid-bed air-oxidation of oil shale in a heated stainless steel.reactor. ■ The effects of tempera­ ture, pressure, shale size, and.oxidation time on yield.were-studied.to find an optimum, set, of operating conditions. A limited study of a simultaneous air-oxidation and extraction.method at .atmospheric pressure was also made. - 7 - ■PROCEDURE EQU I P M E N T A N D MATERIALS A. Procedure and. Equipment 1. Preparation of the Feed The-oil shale obtained, from Green .River* Wyoming, had to be ground and classified before it could be used in the .reactor. The large chunks of shale were broken up by using a sledge hammer and then further reduced ..in size .by a Montgomery Ward-Model G hammer mill. •After-screenings .the.coarser material was further reduced in size by grinding in a ball.mill. A series of Tyler screens , was then used to .classify all of the ground shale. The- screens were shaken on d Roto-tap screen sMker. The shale from the various screens was ,,then blended back in.-the proper ratios to give the desired size distribution for each experimental run. 2. FluidrBed Air-Oxidation The organic.matter in the oil shale was oxidized by fluidizing the shale in a stainless steel reactor (Figure I*. ,page 1W). The reactor consisted of two parts.* the preheat and reaction, zone, and the expansion chamber. The head, for the reactor included a. wash chamber,/ a stainless steel screen* and.a needle valve for adjusting the air rate. , Following the ,needle valve was a .manometer■and a wet test flow..meter to. measure the air rate. The reactor body was made df one-inch (inside diameter) stain­ less steel pipe four feet long.'..,-A, stainless steel screen on a stand one foot from the bottom of the reactor was used as the bed support. - 8 -The section below the screen was filled with one-eighth inch metal, helices. These,, along with the screen.* were used to disperse the air.evenly.oyer the cross-section of the pipe. ■ This section was also used, to preheat the incoming.air. The reaction zone was the three-foot section of pipe above the screen. A six-inch length, of two-inch black iron pipe was welded to the top of the reactor body to serve as an expansion chamber. The body, of the reactor was heated with three nichrome tfire heating coils. This nichrome wire was encased in. ceramic beads. ■One heating coil supplied heat to the air preheat section and the ■other two coils' supplied, heat to the reaction zone. Each nichrome wire heating coil was connected to a. ,110-volt Variac which was used to regulate the energy supply. ■ The -reactor was insulated with approximately two inches of magnesia .mud insulation and then covered with an aluminum sheet to reduce radiation of heat from the reactor. The reactor body was supported on a pivot so the reactor would.rotate about its middle to facilitate dumping. A U -bracket at the bottom of the reactor held it in a vertical position. The reactor head was connected to the top of the reactor body by a two-inch .union. It was necessary to remove the head before loading and unloading the reactor. The reactor head was constructed of one-inch standard pipe except for- a three-inch long.section of one and three quarter-inch pipe which served as an expansion .chamber. The oneinch pipe was the wash chamber. It had valves at ■ both ends to facilitate filling and-draining the scrubber, . A one- ,inch union was placed in the wash chamber so the head could be taken apart and cleaned. Following the expansion chamber was a pressure gauge (0.-60 pounds per square inch) used for measuring' the pressure in the reactor. Following the. pressure gauge was a stainless steel screen and then a. needle valve to. control the air Velocity through the reactor. -The screen was used to keep the fine shale particles,,that are carried completely through the system* ' from, plugging the needle valve. Air was,used.to .fluidize the bed. and also served as a.source of oxygen for the oxidation of the organic material. ■ The air was supplied, at 1$Q pounds per sqpape irich gauge*, by a laboratory compressor. -The entering air passed through a. pressure regulator ■ wbiich controlled the reactor pressure. - The air entered the bottom of the reactor *, passed through the preheat and reactor sections * and left through the scrubber. The air leaving the scrubber passed . through, the needle control., valve that regulated. the air .flow rate. The air then went through an orifice, which was connected to an. inclined air-water ,.manometer, .and finally to a .wet-test meter. The meter was used, to set,the.flow.rate of air. " ' The temperatures in the reactor and. preheat sections were measured with the aid of iron-constantan thermocouples connected to a .Minneapolis-Honeywell "Electronik" temperature indicator. The ", - 9 - 10.* temperature In the air preheat section was measured three Inches below the bed support. A moveable thermocouple was placed In the reaction zone to facilitate taking.a temperature profile of the bed. ■ Erickson (5) - found, a maximum yield of 10.13 per cent when operating.at the following conditions: Air Velocity Temperature Pressure Shale Siae 'Time Bed Weight O.55 fps 200 0C 30.2 psia -12, +100 mesh 30.0 hrs 200 grams He reported that considerable difficulty was encountered, during test runs because of an exothermic reaction taking place which would periodically cause the temperature to get out of control and rise from 200 to. 50O°C uithin seconds. At this temperature> .retort­ ing would.occur- and the run had to be discontinued. After reyiew- .ing .Ericksonts worky it seemed.desirable to try to shorten the oxidation, time by increasing .the operating temperature and pressure. - The problemy; however,* was to prevent runaway temperatures while operating at the more seyene conditions. It was felt that if the bed temperature could be kept within very.narrow limits and a very uniform efficient.fluidization could be maintained, to prevent any stagnation of particles , .the possibility of any, local overheating - U - would be .minimized. It was hoped in this manner to keep the reaction in check and prevent the temperature from getting .out of control. Before .test runs were .madethe reactor was taken apart and cleaned. In an effort to assure more uniform air dispersion across the entire cross-sectional area of the reactor., .the metal helices in, the air preheat section were replaced with new ones and a new. bed support screen of fine mesh was, installed. Experience obtained during .several test runs resulted in the following operating procedure. The empty reaction zone was heated with air flowing through it to ten or fifteen degrees centigrade be­ low, the operating temperature. At this time heat to the reaction zone was. turned off and. the charge .was introduced, to- the reactor. Sufficient air flow.was maintained to keep the bed fluidized while the head was connected and tightened. ■ The reactor was then brought to. operating pressure and the air velocity adjusted to approximately CL.55-feet per second (based.on the empty reactor crosd-section). The ppeheat air was maintained at all times'about thirty-five degrees centigrade below the reaction zone temperature. This.'was done to prevent overheating in. the Very, bottom of .the reaction^zone where fluidization is least efficient. When the temperature became stable after charging,, heat was again applied and the -reactor slowly.brought up to reaction temperature. When the reactor reached operating temperature,,the-pif velocity was again adjusted.to 0.55 feet per second. With these precautions during the start-rup .and with careful 12 control during .the run* It was possible to run. at the desired con- "ditlons with a.minimum.of difficulty. - ' 1 • A series of runs (Runs B-I4 -3, -5) was set up to study the ‘ j effect of Increasing the temperature on the yield while holding the other.variables at the following conditions: 0.55 fps 30.2 psla -12* ,+100 mesh '• 7-0 hrs' 200 grams The temperatures studied were 200*,.220,,.230» 240* .and„250oC.- The first run was made at. 200 and.the next' at 220,,etc. The reason for this was to find the highest operational temperature at the above ■conditions. ■ Two runs were attempted at an operating temperature of 250*0. One of these runs was at a pressure of 30.2 .pSia and ■the-other at atmospheric pressure (12.2 psla). All attempts to operate the reactor at these -conditions failed, because of the in­ ability. to keep the reaction'.in. check and control the temperature. A.study-of pressure effect was next - undertaken. The effect of increasing the pressure from 30.2 psla to .50.2 psla at .200* 220*. a n d .240*0 was investigated. All.other variables were .held at the same, values used,.for.the temperature investigation, ,The highest presshpe that could be maintained., on the unit* with the source, of air available*, was 50.2 psla. ;Air Velocity Pressure Shale ,Size Time Bed. Weight ■- -15 ■ — ■ A series of runs ,(Runs B-Il, -12, -13, -16) was also ;made to study the effect, of time.while operating- at -R^Q0C and ,4-0.2 psia which, appeared, from the preceding, investiga,tipn • to be optimum. • One. .important factor that should be brought out at this point is the fact that.the *12, +100 .mesh shale .Used, above.had. the follow i n g s i z e - d i s t r i b u t i o n : :R e t a i n e d OZl ■ 1 2 m e s h s c r e e n . 0.0 p e r . c e n t . " . .I! 20 ," H 2.4 W1 IL ir -H 55 II. . it 4o, a IT TL it . . n 48 it: 11 21.8 ,11 II Ii TL . 65 n 11 18.1 IT IT II ,10.0. Ii 16.9 IL II. At this point it was decided to investigate, shale', particle ■ size .fpom the standpoint of. its effect on reaction time at the following.conditions: .Air Velocity- ,0.55 fp.s Temperature 2400C Pressure 40.2 psia . For this series of. runs the size .distribution was .as follows; Retained on' ■ 35 mesh screen Q-, 0 per cent I' .1. 48, II IT 21,8 1 1 II .W 65 -U II 18.1 1 1 -IT .1. 100 TI ' IT 16.9 ,1 - it . M 1 150, Tl W 43.2 1 Ir Runs were made at three,;five.,, .seven, and ten hours. - - 14 Since the- effect of using the finer mesh material was to lower the.reaction time necessary.to reach, optimum yield, from seven to fiye hoursy additional, runs.were set up at this point to again, study the effect of temperature and pressure independently, of the -other yaplahles. • To complete a study of the effect of shale.size on yield, runs were .made with the. following size distributions ,at 2400C,- five hours, . O.55 ,feet per Second* and 40.2 psia: -Rpn, -B.-15 Retained, on 12. mesh -screen- O 0-O- per cent I! if a o if Il 2.0 X ■ .11 .!I h 35. U Il 34.1 IT .IT U- Tl 48.' if X- ■ 18.2 -.It n • H- it 6 5 . 11 If 15.0. U X 11. TI I Q O Jt Il 14.1 II Il . 11. U I S O - Ii - Il 16.6 . 11 ii. ,Run B-22 Retained. on 48, mesh, screen. 0.0 per cent II II 65 It if 21.6 II n H . .11 100 it if 2 3 . 2 II n . I! it. 150 !I. X 55.2 11 U RUn,-B-24 Retained oh 12 mesh screen &%0O cent Il V 20 It ■ Il 2 . 9 Tl IT -15 - Rtin B-2U- (continued.) Retained on >5 mesh screen 49.1 per cent " '« 48 y ".. . ■ .26.2 '! " " " 65 " ,f 21.8 " « In order to determine If a ..range of particle sizes Is desirable? runs were.made where the whole reactor charge was taken from, a single screen. These results were then compared to.the yields obtained when a size .distribution was used. The screen sizes used.In. this, study -55 ✓ +48 mesh -48 > ■ +65 mesh -65.^ +100 mesh Due to the previous work done on the extraction step by Erickson (5)?,no investigation was made of any.of the extraction variables. The extraction procedure used throughout this investi­ gation is Shown schematically, in Figure 2* page 45. The amount.of oxidized, OrganicS in the oil shale was determined by the following procedure: . a) Thirty grams of oxidized.oil shale and three hundred mUJiliters of tap water were boiled? while being Stirredf .for one hour. This step was done at total reflux.and atmospheric pressure. ■ The extraction was done in a 600 ml' Berselius beaker. The apparatus is shown in Figure 3,* page 46. were : . Run'B-32 Run B-55 Run B-54 5. ■ Extraction 16 - •Trie .stirrer' shaft pass.ed. through, .a rubber' stopper which. ■was provided with-a .mercury-seal. -The mercury provided a .real between the shaft ahd the rubber stopper, to, keep the water yapor from, escaping ;around the shaft. An adapter was inserted, through, the stopper and.connected to a condenser for total, reflux. The- condenser was open, to the atmosphere. A Bunsen burner supplied the -heat, and a. Fisher 1lFultork Lab^ ..mOt'or" supplied power to the stirring ..Shaft which contained a four-winged, propeller. -b). -The extraction, mixture-was then placed, in a centrifuge for .-one hour to separate the shale from the aqueous. solution, containing the organic compounds. . e) • The aqueous solution was. decanted .from,.the centrifuge containers .and..filtered, to assure, that all the shale partis ■ eles. were removed. ■ d) . Ihes liquid.was acidified.-and.the resulting precipitate Was allowed.to settle to the bottom of,the beaker to facilitate filtering. e) ■ The mixture was filtered.through a weighed, filter paper and. the dried precipitate was measured as part.of the yield. •It was called the acid insoluble portion. — .iy - f) The filtrate from (e) was evaporated to dryness. The ' organics on the salt were extracted with acetone, g) The acetone was distilled from the organic-acetone solution in a distillation flask. The organic residue was again dissolved in acetone and filtered to.remove any solid particles. k) An infrared lamp was used to drive off the acetone frhm the second acetone-organic solution. ■ The organic residue was weighed and recorded as the acid soluble portion. i) . / The total per cent recovery of the oxidized organic material was based, on the sum of the acid soluble and acid insoluble portions, j) All the yields were reported as the grams of oxidized organics per one hundred grams of oxidized, oil shale, A. Identification of ,the.Organic■ Constituents Acetone extracts of the organic material,.obtained, from the Shale oxidized at the following conditions. Air Velocity • 0„55.fps Temperature 240 0C Pressure 40.2 psia Shale Size -35y +150,. mesh 7..0 hrsTime -18 - were evaporated to dryness on. a salt plate to be used In. a Bebhman IR-4 Infraped spectrophotometer. The resulting Infrared analysis charts were to. be compared to the charts made by Suiter (4). 5. Simultaneous Air-Oxidation, and-Extraction The equipment used, in, this part of the study was the same as that shown in Figure 3, page except for two additions. The additions consisted, of an air dispersion tube and a nichrome wire heater. The procedure consisted of boiling a shale^water mixture af atmospheric pressure while introducing.a finely dispersed stream Of air. Each run was. acCompanied .by excessive foaming. The nichrome wire was uniformly stretched back and. forth across the entire cross section, of the beaker about one inch below the stopper and was used to control- .the foam by thermal shock. Only preliminary runs were made to see if the principle of thermal shock would disperse the foam. The test runs were of about twenty hours duration and met With- only limited success. 6.. ■ Large' Quantity .Air-Oxidation, and- Extraction The Food. Machinery- -and -Chemical- Corporation requested about -one pound.of the oxidized organic material for further identification studies. The fluid, bed reactor shown in Figure.1 was too small for this operation and therefore a small rotary kiln was used to oxidize the oil Shale. The .kiln. was. eight inches in. diameter and four feet long. It was electrically.heated. The-oxidized, organics were ex ^ tracted in a steam heated.copper kettle. -The mixture was constantly - .19 * stirred -and -water was added, periodically to .maintain, a -constant. volume,during, the - five-hour extraction time.' B. Materials Oil -Shale'; :The. oil Shale used in. this investigation was.-obtained . from, the lower - shale - bed., at Green River,; -Wyoming. This shale-contains approximately eight to ten. per cent organic ..material. M r : : The - air was supplied, by a laboratory compressor at . 150 pounds per square inch gauge. Acetone: - The acetone used was a commercial grade re-distilled at a 10:I reflux ratio in a thirty theoretical plate packed column. / . • Hydrochloric Acltl: ; Concentrated hydrochloric acid, ,made by Fisher, was used to acidify the extraction solution. -■20 - DISCUSSION OF RESULTS A. .Alr^OxldatlOn In an effort to find ;the optimum operating temperature^ . reaction, temperatures of 200220 , 230y and .240- degrees centigrade were studied. All of the air-oxidation data are tabulated in. Table -I* page 38 « Several attempts were made to operate .the reactor at 25,0*C and. 30.2 pounds per square inch absolute (Run B-l9) y but all .of them failed. All of the failures were due to the uncontrollable exothermic reaction taking place ' just after the shale had .been charged to the reactor. Extreme care was taken during the start of the runs but the temperature could not be controlled. During.one attempted run. the shale was in-the reactor at 25Q*C and 30.2 psia.for four hours and when it was removed,, all of the •organics had been burned off the shale. During this run, after the shale was charged, the heat to the reaction zone was shut off for approxi­ mately, three of the four hours in -order to,maintain the temperature at 250*0. The necessary heat needed to maintain the operating temperature was generated in the reactor. Other runs were attempted at 250*0 and atmospheric pressure (Run B-2l). These runs also had to be discontinued. • Runs at 25O-C and higher pressures were not attempted because it was felt that if the runs could not be made at the lower pressures.there was no ..chanOe of completing -them at higher pressures. For the shale uSed. in . this investigation-, the highest operating temperature that could, be maintained was R1IObC. - 21 - The lower curve (30.2 psla) of Figure 4 ^,page 4?, shows the effect of Increasing the temperature on the yield (Runs B-Ir. -3, .-5) while the operating pressure was held at 30,2.psla* the air velocity at O.55. feet per secondy the oxidation time at seven hours and the shale size at -JBr +100 mesh, (for size distributions r.. see page 13 ). ■ The yield.increased from 1.3 per cent to $.3 per cent when the temperature was increased . from. 200*0 to 240*0. The center curve (40^2 psia) of Figure 4 shows that the yield also increases with temperature over the range studied (Runs B-9-f -IOjf -11) when the pressure is held at 40.2 psia. The yields obtained ■ranged from 2.1 per cent at 20Q°0 to 11,17 per cent at 240*0. No ex­ perimental run was made at 4 0.2 psla. and 250*0 for the reason stated above. Due to lack of precise temperature control*.no runs were .made at 245*0. The top curve (50.2 psia) of Figure 4 r. (Runs B-6r -7r ■ -r.8) *. shows the effect of increasing the temperature on the yield when the Operating pressure is 50.2 .psia. •This curve shows the yield goes through a maximum ' as the temperature increases from 200*0 to 240*0. The maximum yield of 9.58 per cent is obtained at the operating condition of 50.2 psia and 230*0. While this yield represents a ,maximum when operating at 50.2 psia and 230*0r the yield is lower than the maximum yield obtained when opera­ ting at 40.2 psia and 240*0. The same series of experimental .puns '.(B-Ir -3, .-5, -6* -7* .-8 .-9y -,10*.-11.) r.as mentioned above* are plotted in Figure 5 * page 48* showing the per cent yield versus the. oxidation pressure with.the oxidation temperature as the parameter. This was done to show the -effect of oxida­ tion pressure on the per cent yield more clearly than in Figure 4. The 22 - lower and middle curves show .an increase In yield accompanying an increase in pressure at 200°C. The top curve of Figure 5 shows that when the temperature is held at 2400^ C and the pressure is varied from 30.2 'psia to 50.2 psia*.the per cent yield, obtained goes through a.maximum. This maximum yield.of 11.17 per cent.occurred at 40.2 psia and 240°C„ It is pustulated that at some higher pressures the two lower curves would drop off the same as the top curve. With the available source of air,.however, the reactor pressure could not be increased beyond 50.2 psia. Even if some experimental runs could have been made at some higher pressures,.the maximum yield obtained would be somewhat lower than that obtained for the top curve. This series of experimental runs indicates that the oxidation should be.carried.out at 2400C and 40. 2 'psia. Additional runs were therefore made at this temperature and pressure to determine the effect of reaction time on yield." Figure 6,y (Run B-Il, -12? "-13* -16) page 4^, shows a plot of the results of this test series. It is a plot of per cent yield versus oxidation time. The yield goes through a maximum when the time is varied from zero to ten hours. This maximum yield occurred in seven hours. ■ As shopi in Figures 4 and 5? .a decrease in yield resulted, at 5.0.2 psia when the temperature was' increased..from 230°C to 2400C and also decreased, at 24.0°C when the pressure was raised.from 40.2 psia. to 50.2 psia. In light .of the fact that yield apparently decreases when reaction time exceeds certain limits (see Figure 6.? .page. 4 9 ) .it was postulated that the. decreased yield at 240°C and. 50.2 psia might be caused, as a result of exceeding the.-optimum.-reaction, time for these conditions. As a result -of this thinking*,'another time study (Runs B-8*. .-lg* -20, -23) wag made at the,following conditions: : Air Velocity — .23 Temperature Pressure Shale Size Bed. Weight O.55. fps 240° C 50..2 'psia -12* +100 mesh 200 grams The results, are plotted in Figure 7*-page 5).. This time study showed that the.maximum yield w a s .obtained'in. seven hours. It should be pointed put. that these runs were Somewhat erratic and,it was very difficult to..keep the reaction in check: and prevent the temperature from exceeding- the der- sired value of ■ 240 °C. .As. a. result.* ,excessive decomposition, of the organics, probably, occurred. It is .quite apparent> at any pate,, that reaction temperatures above 2400C and. pressures above 40.2 psia are hot practical. As .a result of the investigation to this point,*, the optimum operating conditions were set at the following: : Air Velocity Q r 55'fps 1 Temperature 240*0 Pressure ■ 40.2 psia Shale Size -12,-+100.mesh . ■ Time 7 • 0- hours Bed Wfeight 200.grams - 24 It was believed .that If the surface area were Increased, .the oxida­ tion time might be shortened while still obtaining desirable yields. Additional charges of raw shale in the range of -55., +150 mesh were therefore prepared and a series of runs was designed to study the effect of temperature, pressure, and time.on the per cent yield. On the basis of preceding r e s u l t s a temperature -of 240*0 and a pressure of 40.2 psia were chosen while investigating the effect of reaction time. '• The results of these runs . (B-14., -25/ ^26? ,-31) are plotted in Figure 8> page 51, The increase in surface area of the — 35>, -+150 mesh charge (see page 13-15 for the actual size distribution) over the■■-12, +1.00 mesh material.re­ sulted in a reduction of optimum time from seven to five hours, although . the .maximum yield was only 9.77 per cent as- compared to 11,17 per cent for the -coarser grind. • Using a.reaction time of five hours, .temperature and pressure effects were again investigated. Results of these runs (B-l4, .-27^ -287. .-*29/.^O) are plotted in Figures 9 and 10,>. pages 52-53 y showing yield., versus temperature and pressure/, respectively. These results were similar t:o previous, investigations and verified the use of 240°'C and 40.2 psia as optimum values. Fpom this study* using a size distribution of -35, +150 mesh, the optimum operating conditions: were set as follows; .Air Velocity 0.55 fps 240.° C■ Temperature Pressure 40.2 psia -35* +150 meshShale Size - .25 - ■ Time 5.0 hours' Bed Weight 200 grams The results of the .two above studies.y using different size distribu­ tions ^ Indicate that the finer the average particle size,, ,the shorter the oxidation time. As postulated, the increase in surface area shortened the oxidation time without appreciable sacrifice of yield. With the reactor.used in this investigation, some difficulty was encountered when using .fine shale particles (-100, +150. mesh) as part of the charge. In View.of this., no shale particles smaller than minus 150 mesh were used in this study and no attempt was made to investigate finer grinds than -35? 4-150. mesh. Since particle size and/or size distribution affected the yields and., the oxidation time, it was decided to. investigate this aspect in more detail. ■ Runs B.-13y .-14,.-15>. -24, -32, -33* tabulated in Table ill, page 43, were used, for this study and the results were correlated on the basis of the specific surface of the charge. The specific surface is the total surface area of the particles divided by the weight of the charge. For. this particular study, the shale was assumed to haye pro­ perties. similar to quartz, and.the data presented in Unit Operations by Brown (2) was used.for determining the average specific surfaces, of the various charges. . Average diameters and specific surface for single screen sizes are presented in Table II, page 42 . The specific surface of each charge, presented in Table III, is a weighted average based on the weight fractions retained.on each screen and the specific surface of ■- 26 - the material retained on each scrden. .An example of the calculations • follows! .Shale Size W t . Fraction Specific Surface - 4 8 -+65 mesh 0.216 X 225 - 48.6 -65/ +100 0.232 % 315 = 73.0 -100 x +150 " 0.552 x 420 •= ■232.0 353.6 cm2/gm. All of these funs were made at the following conditions: A^ir Velocity O .55 fps • Temperature 24a°C Pressure 40.2 :psia Time . 5.0 hrs As discussed previousIyx an oxidation, time of five hours was found to be optimum for the size distribution -35/ +150 mesh used in Run b -14. Since the optimum, time would be lowered with a finer grind and since yields decrease as this optimum time is exceeded/ the size distributions for these runs were' all .chosen so that the specific surface was lower . than the 322.3 cm2 .per gram for Run B.-J.4. ■ Therefore, the five-hour •oxidation time would in no instance exceed.the optimum. Figure Ilx •page 54/.is a plot of per cent yield Versus the specific surface of each charge. The upper curve represents the data from shale samples having .a size distribution or fractions from, several screen sizes. This curve shows that the per cent yfield increases as the specific surface (cm2 per gram of shale) increases. -As the specific surface becomes largex the W. 27 - ■per cent yield obtained levels off. The yield of Run B.-24.is somewhat lower than might be expected when compared to the general pattern set by the other three points (Runs B-13y ^l4/.-15). Here, however, the surface area,is not the only factor affecting the yield. It is believed that the fluidization of the bed in the reactor is not as efficient because of the large fraction (52 per cent) of +35 mesh material.present. Shale of this coarseness is.difficult to fluidize. The lower curve of Figure 11, page 54;,. shows the results when charges of shale from a single screen were charged to the reactor. .The .yield increases slightly with a large, increase in,.-specific surface. A compari­ son of the tWO' curves shows the need of a charge with a size distribution in order to obtain desired yields. From, a charge having a size dis- . tribution (-35y • +150 mesh) and specific surface of 322 cnf per gram, of shale, a yield of 9.77 per cent pas obtained and from a similar.charge haying only one screen size (-65* +100 mesh) and a specific surface of 313. Om2 Jper gram, a yield, of only 5.6 per cent was obtained. It is postulated that fluidization is better when a size distribution is used .than when the Qharge is from a single screen. There is very little difference in the yields obtained in Runs B-24 and B-32 even though B-24 had a particle size distribution. This, as stated earlier, may ..be due to poor fluidization of Run. B-24. It is apparent, however, ,that size distribution is desirable and that more .benefit is derived from the distribution of particle sizes, at the higher specific surfaces than at the lower specific surfaces. “ -28 - The per Derit yield per specific surface was plotted, versus the specific surface in Figure 12, page 55 . The top curve is for charges having a Size distribution and the JLouer curve for a charge having a single screen size. As the specific surface increases beyond 175 cm2 per gram, the two. curyes are almost parallel. This figure also shows the need for a charge having a size distribution. A word, of caption is given here about interpreting the data in this pant of the study. A limited study was made of the effect of particle size and. only a few general conclusions can be drawn. Any attempt to set an optimum grind, will require additional investigation. B.. Extraction, of the Organic Material Although a variable study was not made in this investigation^ some reference will.be made to the color of the products. The precipitate (acid insoluble portion of the product) was dark brown to black,, ,depend­ ing Upon how rigorous the oxidations conditions were. The amorphous precipitate turned very dark when it was dried and looked somewhat like a tar material but was hard and brittle. When all the acetone had been removed from the acid soluble portion, the resulting.residue was a dark reddish brown tar-like material. The residue would not .pour at room temperature. • This, residue would change color and become very dark with very little,heat being applied. After all of .the acetone had evaporated-, under an infrared heat lamp,.the residue was no longer entirely soluble in acetone. This would indicate the possibility of decarboxylation and/or polymerization taking place.. The infrared analysis charts show the - 29 - presence of numerous carboxyl groups and.also Indicate that the residue Is a polymer. •C. ■ Identification of Organic Material Dpe to previous work done On identification of the oxidation products y infrared analysis was chosen for trying to identify some of the structural groups present in the product obtained in this investigation. The identi­ fication work done in this investigation was compared to that done by Suiter (4).. The infrared analysis chart for the acid soluble product (Figure .13y page 96) is almost identical to that.made by Suiter. This indicates that the same products were obtained when the oil shale was air- oxidized in a.fluid-bed and when oxidized by using potassium permanganate (by Suiter). The numbers listed below refer to the absorption peaks which are likewise numbered on the infrared analysis charts. Dr. Baker of the. Chemistry Department at Montana State College made and interpreted all of the infrared analysis charts and the results follow: 1. Due to broad band spectra contribution of the OH in a carboxylic acid (-COOH) structure. 2. Due to aliphatic carbon-hydrogen bonding. 3. Broad band due to spectra-contributions of carbonyl ■group's (i.e.y aldehydes and ketones), 4— 5. Broad band spectra characteristic of complex ' acid structures. It should be noticed here that there is no peak at point 6 on Figure 13. There should.be if there are acid dimers present. The fact that there is no peak is not conclusive evidence to rule out the possibility.of acid dimers. ■ Bowevery. the broad bands are characteristic of polymers. ■Figure IJ is presumed to be of a product which is essentially a very complex acid. Figure l4y page >■ is an infrared analysis chart of the - acetone fraction of the acid insoluble product. Again,- this chart was compared to a -similar one made by Suiter. The two wepe found to be just about the same.- -Figure 14 indicates the presence of the same groups. as does Figure 13. However, there is still no peak at 10.6 microns to, indicate the presence of acid dimers. Any unsaturation that -might be present does not show ,beeause of the broad band contribution of the OH in the carboxyl groups and water. It can be concluded that the -acid soluble portion-and .the acetone fraction of the acid insoluble portion have essentially the same structural groups present. -It is possible that the acid insoluble portion is more highly polymerized than the acid soluble portion, -Both portions being essentially complex acids. Further work should be done -on separating some.-.of the components before another infrared analysis is .made. This %puld give a more positive identification of the structural groups present. D . Simultaneous Air-Oxidation ,and Extraction Excessive foaming occurred during the initial runs. This foaming was detrimental, to.the•operation of the-test runs. The foam was dis­ persed by. using a nichrome wire heating coil suspended.above the aqueous mixture. In order for the wire.heater to be effective,,, it had, to be " 31- - "red. hot". If the foam dried on. the w i f e t h e wire then became in­ effective . .The rate at which the ftiam dould be dispersed dictated the air rate. The yields obtained were approximately 1.3 to.1 .8 per cent. -An oxidation time of twenty hours was required to obtain these yields. The yields indicate that some of the organic material can be removed by this process. Because of the lew yields the work on this phase of this investigation was discontinued. I I StIMMARY The•maximum yield obtained, in this investigation was 11.17 per cent The oxidation conditions were as follows; . - 32 T. : Temperature .240 0C Pressure 40.2 psia . Air Velocity 0.55 fps Shale Size -12 i +10.0 mesh Time 7.0 hours Bed Weight 200 grams These operating conditions represent the optimum operating conditions when a.shale size distribution of -I2y +100.mesh, was used. The optimum, .operating.conditions chosen for this investigation follow; . Temperature 24o °c Pressure - 40.2 psia Air Velocity O .55 fps Shale Size — 35? +159 mesh Time 5.0 hours Bed Weight 200 grams At these optimum conditions;* a yield, of 9.77 per cent was obtained, It was decided to select these as the optimum conditions because the oxidation time required was only five hours. - 33 - The .results of this investigation show the need.for-a charge having ■a size distribution. From a charge having a size distribution, and ■ specific-surface of 322 cm2 per gram of shale > a yield ,.of SirJ1J per. cent was obtained^ and from a similar charge having only one screen size and a ..specific surface of 315 cm§ per gram,, a yield of. only $.6 per cent was obtained. These two runs were made at the above.operating .conditions except that the particle size was changed. The organic products.^ .resulting from the oxidation .of oil shale, are essentially highly complex acid polymers. Yields.of I.3,to 1.8 per.cent were.obtained during the simultaneous air-oxidation and extraction. These yields were so low that the study was discontinued. 34 ■* ■ RECOMMENDATIONS Farther work could, be done .in continuation -of this.research project. A complete- study should, be made of the effect of particle size and size distribution on the yield. AlsOy the extraction step could, ,be investigated to find, out if any inorganic, .material is passing through the filter papers. ■ This material might be in a collodial state. ■ The results of this investigation could be compared, with those ■obtained from. Green River top shale and. the Colorado shale. When the oxidized ..organic material.is identified, a study should be made to find the optimum conditions that give the most desirable product. ? 5 - BIBLIOGRAPHY ' 1. Bell* H. S, Oil Shales and Shale- Oils, D. Van No'strand.Companyf -Inc.,- New Yorky N.Y.* 1948. 2. Brown, George G., Unit Operations> ,John Wiley & Sons, Inc., New. York., N. Y. , ,1950. ■5. Erickson* Larry L . Extraction -of Organic Materials From Green River, Wyoming Oil Shales, M.S.• Thesis, Montana State College, i960 4. ' Suiter, Raymond C.., Extraction of Organic Materials From Green River, Wyoming Oil Shales, M.S*. Thesis , Montana State College, 1959 T-V 36 -• a c k n o w l e d g m e n t ,The author-washes to thank the Food Machinery- and.Chemical .Cor-^ p.oration for sponsoring this research project. The author also wished - ' I to thank Professor H. A. Saner and.-Research. Fellow -Raymond Porter of the Chemical-Engineering Department/ Montana State College, for their aid and. suggestions, on. this project. page Table I ,MrrOxldatlon and Extraction Data .................... . 38 • APPENDIX Mr Oxldat Table II Specific Surfape for Each Screen Size . . . . . . 42 Table III Data, for Figures. 11 and. 12 . . . .............. : 43 Figure I Air-Oxidation FluldrBed Reactor . . . . . . . . 44 Figure .2 Extraction, and. Analysis Flow Diagram. . . 4.5 Figure 3 Open Boiling Apparatus . . . ... 46 Figure 4 Effect of Oxidation Temperature on the.Yield . . . 4j Figure 5 Effept of- Oxidation Pressure on the.Yield . . . . .48 - Figure 6 Effect of Oxidation Time on. the Y i e l d ................. 4$ Figure 7 Effect of Oxidation Time on the Yield . . ... . . . 50 ■Figure 8 Effect of Oxidation Time.on the --Yield ' . . . . . 51 • Figure 9 Effect of Oxidation ;Temperature on .the- Yield . . . 52 . Figure 10 Effect of Oxidation. Pressure on the.Yield .. ...... 53 Figure 11 Effect of Specific Surface, on the Yield............... 54 Figure.12 Yield per Specific Surface versus .Specific Surface . . ... . .....................55 ' Figure 13 ' 'Inirared Analysis of Products .. . ' . . . . . 56 Figure l4 Infrared. Analysis of Products . . . . . . . . . . 56 V •- 37- - TABLE I. AIR-OXIDATION AND EXTRACTION DATA GREEN RIVER, WYOMING, BOTTOM SHALE Run N o . Size (Mesh) Oxld1n Time Hr. Oxld'n Temp. °C. Oxld1n Pressure Psla Air Veloc, Fps Extract. Extract. Time Temp. Hr. 0C. Acid Acid Insol. Sol. Cm. Ga. Per Cent Yield B-I -12 +100 7-0 200 30.2 0.55 1.0 96 O.O87 0.095 1.30 B-3 -12 +100 7.0 220 30.2 0.55 1.0 96 0.188 0.145 2.13 B-5 -12 +100 7.0 240 30.2 0.55 1.0 96 0.959 0.102 9.48 b -6 -12 +100 7.0 200 50.2 0.55 1.0 96 0.174 O.I85 2.24 B-7 -12 +100 7.0 220 50.2 0.55 1.0 96 0.579 0.156 6.34 b -8 -12 +100 7.0 240 50.2 0.55 1.0 96 0.737 0.108 7.51 b -9 -12 +100 7.0 200 40.2 0.55 1.0 96 O.I75 0.148 2.08 B-IO -12 +100 7-0 220 40.2 0.55 1.0 96 0.520 0.140 5.57 B-Il -12 +100 7.0 240 40.2 o.55 1.0 96 1.094 0.124 11.17 B-12 -12 +100 3.0 240 40.2 0.55 1.0 96 0.355 0.131 3.38 B-13 -12 +100 5.0 240 40.2 0.55 1.0 96 0.681 0.125 6.86 TABLE I. (continued) Run No. Size (Mesh) Oxld1n Time Hr. Oxld1n Temp. 0C. Oxid'n Pressure Psla Air Veloc. Fps B-14 -35 +150 5.0 240 40.2 0.55 B-15 -12 +150 5.0 240 40.2 X 40.2 0.55 B-16 -12 +100 10.0 240 0.55 B-17 -12 +100 7.0 230 50.2 0.55 B-l8 -12 +100 3.0 250 30.2 0.55 B-19 -12 +100 5.0 240 50.2 0.55 B-20 -12 +100 3.0 240 50.2 0.55 B-21 -12 +100 — — — 250 Atm. 0.55 B-22 -48 +150 5-0 240 40.2 0.55 B-23 -12 +100 10.0 240 50.2 0.55 B-24 -12 5.0 240 40.2 0.55 +70 Extract. Time Hr. Extract. Temp. °C. Acid Insol, Gm. Acid . Sol. an. Per Cent Yield 1.0 96 1.050 0.153 9-77 1.0 96 O .876 0.098 8.01 1.0 96 0.961 0.111 8.63 1.0 96 1.085 0.108 9.58 C o u I d n o t r u n 1.0 96 0.374 0.105 3.89 1.0 96 0.352 0.111 3.76 C. 0 u I d n 0 t r u n 1.0 96 0.963 0.145 7.75 1.0 96 0.444 0.246 5.24 1.0 96 0.356 0.122 4.77 i Vj4 VO TABLE I. (continued) Run No. Size (Mesh) Oxid1n Time Hr. Oxid1n Temp. °C. Oxid'n Pressure Psia Air Veloc. Pps Extract. Time Hr. Extract. Temp. 0C. Acid Insol. Cm. Acid Sol. Gta. Per Cent Yield B-25 -35 +150 3.0 240 40.2 0.55 1.0 96 0.419 0.097 4.56 B-26 -35 +150 7.0 240 40.2 0.55 1.0 96 0.501 0.160 5.95 B-26R -35 +150 7-0 240 40.2 0.55 1.0 96 0.699 0.172 6.81 B-27 -35 +150 5-0 240 30.2 0.55 1.0 96 0.938 0.163 9.07 B-28 -35 +150 5.0 240 50.2 0.55 1.0 96 0.371 0.164 5.06 B-29 -35 +150 5-0 200 40.2 0.55 1.0 96 0.126 0.115 2.10 B-50 -35 +150 5.0 220 40.2 0.55 1.0 96 0.349 0.168 4.67 B-31 -35 +150 10.0 240 40.2 0.55 1.0 96 0.385 0.168 6.09 B-32 -35 +150 5.0 240 40.2 0.55 1.0 96 0.636 0.129 6.70 B-33 -48 +65 5.0 240 40.2 0.55 1.0 96 0.379 0.162 5.15 TABLE I. (continued) Run No. Size (Mesh) Oxld1n Time Hr. Oxld1n Temp. °C. Oxld1n Pressure Psla Alr Veloc. Fps Extract. Time Hr. Extract. Temp. 0C. Acid Insol. Gm. Acid Sol. Gm. Per Cent Yield B-34 -65 +100 5-0 240 40.2 0.55 1.0 96 0.451 O.lBO 5.60 B-35 -48 +150 3.0 240 40.2 0.55 1.0 96 0.505 0.126 6.15 I -F M - 42 - TABLE II Specific Surface For Each Screen Size Screen Size Average Diameter Specific Surface -14, +20 mesh 0.0394 in. 87 cm2/gm. -20, +35 mesh 0.0239 in. 130 cm2/gm. -35» +48 mesh 0.0140 in. 170 cm2/gm. -48, +65 mesh 0.0099 in. 225 cm2/gm. -65» +100 mesh 0.0070 in. 315 cm2/gm. -100, +150 mesh 0.0050 in. 420 cm2/gm. - 43 - TABLE III Data For Figures 11 and 12 Run No. *Size Distribution Specific Surface of Charge Per Cent Yield Per Cent Yield per Specific Surface B-13 -12, +100 186.1 cra2/gm. 6.86 0.0368 B-14 -35, +150 322.3 " 9.77 0.0303 B-15 -12, +150 224.8 " 8.01 0.0356 B-24 -12, +65 159.8 " 4.77 0.0298 B-32 CO%LAI 170.0 " 4.78 0.0281 B-33 LA VO+CO 225.0 " 5.15 0.0229 B-34 -65, +100 315.0 " 5.60 O.OI78 * For actual screen analysis, see pages 13, 14, and 15. - 44 Pressure Gauge Orifice Thermocouple .Wet Test Meter Needle Valve Scrubber Stainless Steel Pipe Nichrome Wire Aluminum Shield Screen Pressure Regulator Insulation Thermocouple Needle Valve Figure I. Air-Oxidation Fluid-Bed Reactor. - 45 - Water 300 ml Oxidized Shale 30 Grams Removal of Inorganic Salts Centrifuge Filtration of Extract Extraction with Acetone Evaporation of Filtrate to Dryness Removal of Acetone from Acid Soluble Organics HCl Acidification of Filtrate Tar-like Acid Insoluble Organics Filtration of Precipitate Figure 2. Extraction and Analysis Flow Diagram. - 46 - Stirrer Motor Beaker Propeller Burner Condenser Figure 5. Open Boiling Apparatus. Y i e l d (P e r C e n t of S h a l e W e i g h t ) - 47 - Time : 1J .0 hours Size: -12, +100 mesh Air Velocity: 0.55 fps Oxidation Temperature (0C) Figure 4. Effect of Oxidation Temperature on the Yield. Y i e l d (P er C e n t of S h a l e W e i g h t ) - 48 - Size: -12, +100 mesh Time: ?.0 hours Oxidation Pressure (Psia) Figure 5. Effect of Oxidation Pressure on the Yield. Y i e l d (P er C e n t of S h a l e W e i g h t ) - 49 - Temperature 40.2 psia -12, +100 mesh Pressure Size 0 2 4 6 8 10 Oxidation Time (hr) Figure 6. Effect of Oxidation Time on the Yield. USSlij Y i e l d (P er C e n t of S h a l e W e i g h t ) - 50 - Temperature Pressure Size 50.2 psia -12, +100 mesh Oxidation Time (hr) Figure 7 . Effect of Oxidation Time on the Yield. Y i e l d (P er C e n t of S h a l e W e i g h t ) - 51 - Temperature Pressure Size 40.2 psia -55» +150 mesh Oxidation Time (hr) Figure 8 Effect of Oxidation Time on the Yield. - 52 - Pressure: 40.2 psia Size : -35» +150 mesh Time : 5-0 hours Oxidation Temperature (0C) Figure 9- Effect of Oxidation Temperature on the Yield. Y i e l d (P er C e n t of S h a l e W e i g h t ) - 53 - 12 I I 2 - 30.2 40.2 50.2 Oxidation Pressure (psia) Figure 10. Effect of Oxidation Pressure on the Yield. Y i e l d (P e r C e n t of S h a l e W e i g h t ) Screen Specific Surface (cm2/ gm) Figure 11. Effect of Specific Surface on the Yield. P e r C e n t Y i e l d p e r S p e c i f i c S u r f a c e 0.0:- Specific Surface (cm2/gm) Figure 12. Yield per Specific Surface versus Specific Surface. 56 WAVELENGTH IN M ICRONS 12 13 14 15 16 2000 1900 180035005000 4500 1200 1100 WAVENUMBER IN KAYSERS Figure 13. Infrared Analysis of Products WAVELENGTH IN M ICRONS Figure 14. Infrared Analysis of Products MONTANA STATE UN IVERSITY L IBRAR IES N378 J637 cop .2 149514 Johnson, R . H. Extraction of organic materia] - £ £ f l n L - G £ g g H _ R i v e r . U v r m v i n o n -i I anale SFVJ8 18»* 'V OCT 2 3 m , , ^ 7 lT YiJ Ci, V* - < ~ ■ V - :»v > . ■ QGT f t m >TJcii Yu M y.f <, /V ://•' i V L' I / 1 4 9 5 1 4