Oil Shale, Tar Sands, and Related Materials - American Chemical

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D. F. BUROW and R. K. SHARMA Department of Chemistry, University of Toledo, Toledo, OH 43606

Development of o i l shale deposits as sources of fuels, lubricants, and chemical feedstocks is being considered as an alternative to present reliance on conventional petroleum reserves. Procedures, advantages, and disadvantages for mining/ surface processing and for in situ retorting have been widely discussed (1, 2, 3). In the former approach, crushing of the shale is essential for efficient o i l recovery. As a result of tests with a variety of mechanical crushers (4), i t is apparent that the effectiveness of mechanical crushing is limited by the characteristics of the shale. A slab-forming tendency allows large pieces to pass through many conventional crushers. The resilience and slippery nature of the shale limits the effectiveness of mechanical impact. Furthermore, shale abrasiveness and a tendency for the shale to adhere to crusher surfaces causes maintenance problems with crushers. In situ retorting is enhanced by fracturing with explosive charges or expansion of existing fractures with fluids such as water. Fracturing by explosive charges is frequently limited to the vicinity of the charge since the explosive shock is dissipated by shale resilience. Efficient fracturing by aqueous fluids is limited by a tendency for capillary adhesion of water in the fissures and by available water supplies in arid regions where o i l shale deposits often occur. Employment of chemical comminution techniques for surface processing of o i l shales could circumvent many of the limitations to mechanical crushing as well as reduce or eliminate capital and maintenance costs of crushers. For in situ processing, such techniques could provide an alternative to explosive or hydrostatic fracturing. Our recent success in comminuting and desulfurizing coal by treatment with liquid sulfur dioxide 05, 6), suggested that similar treatments might be successfully applied to o i l shale processing. Liquid SO2 is a remarkably subtle and selective solvent with moderate Lewis acid properties, a substantial resistance to oxidation and reduction when pure, and a propensity to support a 0097-615 6/81/0163-0025 $05.00/0 © 1981 American Chemical Society

Stauffer; Oil Shale, Tar Sands, and Related Materials ACS Symposium Series; American Chemical Society: Washington, DC, 1981.

26

OIL

SHALE,

T A R SANDS,

AND RELATED

MATERIALS

v a r i e t y o f i o n i c , f r e e r a d i c a l , and molecular r e a c t i o n s (7) . P h y s i c a l p r o p e r t i e s of l i q u i d SO2 which can be e x p l o i t e d advantageously i n c l u d e : a -10° bp, moderate vapor pressure a t room temperature, high d e n s i t y , low v i s c o s i t y , and low surface t e n s i o n . Since SO2 has a b o i l i n g p o i n t of -10°C, i t i s e a s i l y l i q u i f i e d and/or removed a f t e r r e a c t i o n ; i t can be e a s i l y manipulated without the need f o r e x o t i c c o n s t r u c t i o n m a t e r i a l s . Furthermore, i t i s an inexpensive m a t e r i a l which i s r e a d i l y a v a i l a b l e i n l a r g e q u a n t i t i e s from smelting and f o s s i l f u e l combustion; i f not u t i l i z e d , i t must be disposed o f i n some s t a b i l i z e d form a t cons i d e r a b l e expense. Thus, the d i r e c t use of s u l f u r d i o x i d e could provide an a l t e r n a t i v e means o f cost recovery f o r p o l l u t i o n abatement technology. Here we wish t o r e p o r t the r e s u l t s o f p r e l i m i n a r y e x p e r i ments i n which o i l shales are t r e a t e d with l i q u i d s u l f u r d i o x i d e to e f f e c t f r a c t u r i n g ; observations made during these experiments suggest that l i q u i d SO2 may a l s o be of u t i l i t y i n other phases of o i l shale p r o c e s s i n g . We a r e , p r e s e n t l y , unaware of any previous r e p o r t s o f such experiments. Experimental S u l f u r d i o x i d e was d r i e d and manipulated as described e l s e where ( 7 ) . A 1 - l i t e r s t a i n l e s s s t e e l autoclave (Parr Model 4641) was u t i l i z e d f o r p r o c e s s i n g a t pressures i n excess o f c a . 3 atm. In experiments u t i l i z i n g l a r g e r shale pieces (6-8 cm), clamped shale samples, or s u p e r c r i t i c a l c o n d i t i o n s , samples were placed d i r e c t l y i n the autoclave. For s u b - c r i t i c a l experiments using small shale p i e c e s , samples were sealed i n f r i t t e d g l a s s tubes with l i q u i d SO2 ( c a . 2:1 or l e s s S02/shale by weight) to f a c i l i t a t e recovery of e x t r a c t s . S u l f u r d i o x i d e was d i s t i l l e d on to the shale a t -78°C; the system was then sealed and brought up to p r o c e s s i n g temperature. Temperatures of 25, 70, and 170°C were used; s u p e r c r i t i c a l c o n d i t i o n s f o r SO2 were achieved a t the l a t t e r temperature. Processing time was c a . 2 hours f o r elevated temperature experiments; f o r room temperature experiments, the time ranged from 2 t o 24 hours. No mechanical a g i t a t i o n was employed. Upon c o o l i n g , the SO2, s h a l e , and e x t r a c t were recovered. The shales were inspected immediately upon recovery and a t s e v e r a l i n t e r v a l s thereafter. S u l f u r analyses and i n f r a r e d s p e c t r a o f the shales were performed on o r i g i n a l , processed, and processed/heated samples to determine r e s i d u a l SO2 content. I n f r a r e d s p e c t r a of the e x t r a c t s were a l s o obtained. A l l i n f r a r e d s p e c t r a were recorded on a P e r k i n Elmer Model 621 spectrophotometer; s o l i d samples were examined as KBr p e l l e t s and shale e x t r a c t s were examined as t h i n f i l m s (neat) between NaCl p l a t e s . Shale samples were a l s o t r e a t e d with gaseous SO2, l i q u i d CO2, l i q u i d NH3, water, and s e v e r a l organic l i q u i d s at 25°C f o r 2 days. Procedures e q u i v a l e n t t o those used with l i q u i d SO2 were


3.

BUROW A N D SHARMA

Fracturing

of

Oil

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27

employed f o r treatment with gaseous SO2, l i q u i d CO2, and l i q u i d NH3. Treatment with other l i q u i d s c o n s i s t e d of immersion of shale samples i n the l i q u i d contained i n covered beakers. Samples of Antrim, Green R i v e r , and Moroccan o i l shales were obtained from the Laramie Energy Technology Center. The composit i o n of t y p i c a l samples of these three shales i s i l l u s t r a t e d i n Table I. Results and D i s c u s s i o n Upon exposure of the shales to l i q u i d SO2, h i g h l y c o l o r e d s o l u t i o n s develop due to formation of donor-acceptor complexes between e x t r a c t e d o i l c o n s t i t u e n t s and the SO2. Green R i v e r shale produces red-brown s o l u t i o n s , Moroccan shale forms orange s o l u t i o n s , and Antrim shale forms yellow s o l u t i o n s ; i n each case, these c o l o r s are more intense when higher p r o c e s s i n g temperatures are used. F r a c t u r i n g of Shales. L i q u i d SO2 causes extensive f r a c t u r i n g i n each of the three shales examined i n t h i s p r e l i m i n ary study; Figure 1 i l l u s t r a t e s r e p r e s e n t a t i v e examples of t h i s f r a c t u r i n g . T h i s f r a c t u r i n g occurs both along and across l a m i n a t i o n s . With the l a r g e r lumps, laminations are f r e q u e n t l y expanded to 1-2 cm; f r a c t u r e s across laminations are l e s s pronounced but d i s t i n c t l y v i s i b l e . Green River shale e x h i b i t s numerous small cracks whereas the other two shales e x h i b i t a fewer number of l a r g e r cracks. With p r o c e s s i n g temperatures below 25°C, the degree of f r a c t u r i n g i s g r e a t e s t i n Moroccan and l e a s t i n Antrim shale; with higher p r o c e s s i n g temperatures, d i f f e r e n c e s i n degree of f r a c t u r i n g are not so apparent. Samples of each of the s h a l e s , r i g i d l y clamped both across and along laminations a l s o e x h i b i t e d extensive f r a c t u r i n g . Immedia t e l y upon recovery from the r e a c t o r , the samples are so b r i t t l e as to be e a s i l y broken with the f i n g e r s ; a f t e r standing f o r a time, the samples become s l i g h t l y l e s s b r i t t l e but a l l f r a c t u r i n g i s maintained. Although no q u a n t i t a t i v e t e s t s of mechanical p r o p e r t i e s have been made, i t appears t h a t l i t t l e of the r e s i l i e n c e and s l i p p e r y n e s s of the o r i g i n a l shales i s r e t a i n e d . Surfaces of the processed samples have a s o f t l u s t e r o u s appearance. Shale samples were subjected to treatment with other f l u i d s at 25°C to provide comparative data on t h e i r a b i l i t y to f r a c t u r e these s h a l e s . From among these f l u i d s o n l y gaseous SO2, l i q u i d NH3, and methylene c h l o r i d e were e f f e c t i v e f r a c t u r i n g agents under these c o n d i t i o n s . The r e s u l t s are summarized i n Table I I . Under the same c o n d i t i o n s of temperature and pressure, gaseous SO2 i s l e s s e f f e c t i v e than the l i q u i d i n producing f r a c t u r e s . Both l i q u i d NH3 and methylene c h l o r i d e produce roughly the same degree of f r a c t u r i n g as l i q u i d SO2. L i q u i d NH3, however, appears to produce the greatest f r a c t u r i n g with Antrim shale and the



a. b. c. d. e.

Organic Matter: Oil Yield:

9

d e

C nmr

d e 11% (3:1 a l i p h a t i c / a r o m a t i c ) * vL8 gal/ton

9% (1:1 a l i p h a t i c / a r o m a t i c ) VL0 gal/ton 45% 30% 5% 5%

Samples provided by F. M i k n i s , LETC Ref. 8. Ref. 9. Ref. 10. A l i p h a t i c / a r o m a t i c r a t i o e s t a b l i s h e d from s o l i d s t a t e s p e c t r a , Ref. 10.

Moroccan

Organic Matter: Oil Yield: Illite: Quartz: Pyrite: Carbonates:

Organic Matter: Oil Yield: Dolomite and C a l c i t e : Feldspar and P l a g i o c l a s e : I l l i t e , M o n t m o r i l l i n i t e , Muscovite: Quartz: c Antrim (Michigan)

Examined

d e 14% (mostly a l i p h a t i c ) ' ^25 gal/ton 43% 16% 13% 9%

T y p i c a l Composition of O i l Shales

Green River (Colorado)

Table I.

BUROW AND SHARMA

Fracturing

of

Oil

Shale

Figure 1. Representative examples of the fracturing of oil shales by liquid S0 ; (left) treated samples; (right,) untreated samples; (a) Antrim shale treated at 170°C for 2 h; (b) Green River shale treated at 70°C for 2 h; (c) Moroccan shale treated at 70°Cfor2 h. 2


Stauffer; Oil Shale, Tar Sands, and Related Materials ACS Symposium Series; American Chemical Society: Washington, DC, 1981. 2

N N N HF,E

-

-

DMF

HMPA

2

H

b.

a.

-

-

-

-

-

-

HF,E

N

HF,E HF,E HF,E HF,E

-

Moroccan

3

Except f o r l i q u i d S 0 , t e s t s were run a t 25°C f o r 2 days. N: no apparent f r a c t u r i n g , MF: moderate f r a c t u r i n g , HF: extensive f r a c t u r i n g , E: e x t r a c t observed.

6 6 H CC1

2

N

-

C

N

DMSO

3

N

2

-

HF,E

HF,E

N

-

( L i q u i d , VL0 atm)

N

CH CN

3

NH

( L i q u i d , ^60 atm)

H 0

2

C0

MF,E MF,E HF,E HF,E HF,E

-

Gas (^3 atm) L i q u i d (-78°C) L i q u i d (25°C) L i q u i d (70°C) S u p e r c r i t i c a l (170°C) N MF,E HF,E HF,E

Green R i v e r

3

Antrim

Shales*

F r a c t u r i n g o f O i l Shales by Various F l u i d s

Fluid

Table I I .

3.

BUROW A N D SHARMA

Fracturing

of

Oil

Shale

31

l e a s t with Moroccan shale; t h i s trend i s j u s t the opposite o f that observed with l i q u i d SO2. Our r e s u l t s with l i q u i d CO2 are i n apparent c o n f l i c t w i t h r e s u l t s reported by M i l l e r , et a l . (11) for treatment o f Devonian shales with CO2 f l u i d s . From among the f l u i d s t e s t e d , l i q u i d SO2 has s e v e r a l advantages as a f r a c t u r i n g agent f o r o i l s h a l e s : i t i s low i n c o s t , i t i s a v a i l a b l e i n q u a n t i t y , i t i s not d e r i v e d from e i t h e r petroleum or n a t u r a l gas, and i t i s r e a d i l y manipulated due t o i t s moderate vapor pressure. The s u l f u r content of the shales i s increased somewhat by p r o c e s s i n g i n l i q u i d SO2; r e s i d u a l s u l f u r i n c r e a s e s s i g n i f i c a n t l y with the temperature of the treatment, however. For example, at room temperature, r e s i d u a l s u l f u r i n c r e a s e s by 1-2% but a t 170°C, i t i n c r e a s e s by 5-10%. Comparison of i n f r a r e d s p e c t r a of untreated and t r e a t e d shale samples (Figures 2-4, A and B) i n d i c a t e s that t h i s increased s u l f u r content i s due to formation of sulfur-oxygen c o n t a i n i n g r e s i d u e s , probably s u l f i t e s and/or s u l f a t e s , i n the s h a l e s . I t might appear that the increase i n s u l f u r content o f any shale f r a c t u r e d by l i q u i d SO2 would be d e l e t o r i o u s to o i l produced i n a subsequent r e t o r t i n g step. However, s i n c e t h i s r e t a i n e d SO2 appears t o be i n the i n o r g a n i c part o f the shale as adsorbed SO2, s u l f i t e s , or s u l f a t e s , l i t t l e contamination o f the r e t o r t e d o i l should occur: adsorbed SO2 can be removed i n a m i l d preheating step and the s u l f i t e / s u l f a t e species are s u f f i c i e n t l y s t a b l e to remain i n t a c t during any r e t o r t i n g step. S u l f u r elemental and i n f r a r e d analyses o f t r e a t e d shale samples, performed before and a f t e r m i l d h e a t i n g , demonstrated that adsorbed SO2 can be removed e a s i l y . P r e l i m i n a r y SEM/EDXA r e s u l t s f o r Green River Shale i n d i c a t e that these sulfur-oxygen r e s i d u e s are apparently a s s o c i a t e d with s e l e c t e d i n o r g a n i c c o n s t i t u e n t s of the s h a l e . EDXA o f untreated Green River shale samples i n d i c a t e d a Si/Ca r a t i o o f c a . 1.5; t h i s r a t i o corresponds c l o s e l y to that expected from the b u l k composition o f the shale (Table I ) . The s u l f u r which i s present i n untreated samples was observed to be c o r r e l a t e d with Ca r a t h e r than Fe l o c a t i o n s , suggesting that l i t t l e p y r i t i c s u l f u r was present i n these p a r t i c u l a r samples. Treated samples of Green River shale e x h i b i t e r o s i o n and p i t t i n g o f the s u r f a c e i n Ca r i c h areas but no apparent changes i n S i r i c h areas. The p i t s have diameters i n the 2-10 ym range. In t r e a t e d samples, the Si/Ca r a t i o was o f t e n found to be s i g n i f i c a n t l y higher than i n untreated samples; t h i s observation suggests that l i q u i d SO2 causes a surface d e p l e t i o n o f Ca i o n s . The increased s u l f u r content of t r e a t e d samples i s r e a d i l y apparent i n the EDXA r e s u l t s ; t h i s increased S content i s a s s o c i a t e d with Ca r i c h but not S i or Fe r i c h regions i n the s h a l e . These SEM/EDXA data suggest that l i q u i d SO2 a t t a c k s the c a l c i t e and/or dolomite c o n s t i t u e n t s o f Green River shale and, perhaps, thereby causing the observed f r a c t u r i n g . S i m i l a r data on the other shales were not obtained during t h i s e x p l o r a t o r y work.



2

2

Figure 2. IR spectra of Green River oil shale: (a) untreated sample; (b) sample treated with liquid S0 at 70°C for 2 h; (c) sample treated with S0 fluid at 170°C for 2 h; (d) extract isolated from treatment in b.

on

r

Η W

α >

Η W

>

w

σ

>

> υ

w Η

on

ssr

F

Ο

to


Figure

3. 2

IR spectra of Morrocan oil shale: (a) untreated sample; (b) sample treated with SO at70°C for 2 h; (c) extract isolated from treatment in b.

W A V E N U M B E R (CM)

liquid


Figure 4. 2

IR spectra of Antrim oil shale: (a) untreated sample; (b) sample treated with liquid SO at70°C for 2 h; (c) extract isolated from treatment in b.

00

Η W

>

σ

Η W

>

Ζ

>

GO

>

Η

w

Ρ a r

Ο

3.

Fracturing

BUROW A N D SHARMA

of

Oil

Shale

35

F r a c t u r i n g of Model M i n e r a l s . Further i n s i g h t i n t o the p r o cesses r e s p o n s i b l e f o r l i q u i d SO2 f r a c t u r i n g of these shales i s provided by the behavior of s e v e r a l m i n e r a l s when subjected to l i q u i d SO2. Authenic samples of c a l c i t e ( c r y s t a l s ) , dolomite (hard lumps), gypsum (hard lumps), and i l l i t e (hard lumps) were t r e a t e d with l i q u i d SO2 at 25°C f o r 2-5 hours; a f t e r removal of the SO2, the t r e a t e d minerals were heated f o r 2 hours at 100°C; i n f r a r e d s p e c t r a and s u l f u r analyses were then obtained. Calcite c r y s t a l s developed numerous f i n e cracks and a f i n e powder f l a k e d off. Although the powder contained no s u l f u r (elemental a n a l y s i s ) or S-0 m o i e t i e s (IR s p e c t r a ) , the cracked c r y s t a l s were shown to c o n t a i n 0.18% s u l f u r i n the form of sulfur-oxygen s t r u c t u r e s . Although these data are c o n s i s t e d w i t h a 0.7% conversion v i a O p Z5

CaC0 (s) + S 0 U ) 3

±

-

2

> CaS0 (s) + C 0 ( s ) 3

2

other processes cannot he excluded at t h i s stage. Dolomite, on the other hand, d i d not appear to be e f f e c t e d by l i q u i d SO2 under the c o n d i t i o n s employed: t r e a t e d dolomite e x h i b i t e d no f r a c t u r ing, no s u l f u r content, and no mass change. Gypsum chunks were f r a c t u r e d by l i q u i d SO2. I n f r a r e d and s u l f u r analyses i n d i c a t e that l i q u i d S0 i n t e r a c t s with gypsum i n two ways: f i r s t , simple e x t r a c t i o n o f water of c r y s t a l l a t i o n and, second, r e a c t i o n with a p o r t i o n of the remaining water of c r y s t a l l a t i o n to form H and HSO3. Large cracks develop and a powder f l a k e s o f f when i l l i t e lumps are t r e a t e d with l i q u i d SO2; s u l f u r analyses i n d i cate approximate compositions to be iKAl^SiAK^o(OH)4]•(SO2)0.3 (lumps) and [KAli SiA10 o(OH)i ] • (S0 ) o.> (powder). I n f r a r e d s p e c t r a l changes suggest p a r t i a l r e a c t i o n of the OH groups to form SO3H groups. 2

+

t

2

+

2

F r a c t u r i n g Mechanisms. These observations with model minerals suggest that s e v e r a l mechanisms be considered f o r the observed f r a c t u r i n g of o i l shales by l i q u i d SO2. P a r t i a l conv e r s i o n of carbonates to s u l f i t e s could d i s r u p t m i c r o c r y s t a l l i n e l a t t i c e s i n carbonate r i c h s h a l e s . P a r t i a l r e a c t i o n of the OH groups i n a l l u m i n o s i l i c a t e s could cause s i m i l a r changes i n s i l i c e o u s s h a l e s . E x t r a c t i o n of or r e a c t i o n with water of c r y s t a l l i z a t i o n i n shale components could be o p e r a t i n g i n both types of s h a l e . P u r e l y p h y s i c a l processes, perhaps i n v o l v i n g p e n e t r a t i o n o f pores and m i c r o s c o p i c vacancies w i t h subsequent a d s o r p t i o n to modify surfaces or d i s p l a c e s u r f a c e water, need to be considered as w e l l . F i n a l l y , our observations that the v i t r i n i t e s are e x t e n s i v e l y f r a c t u r e d when c o a l s are t r e a t e d with l i q u i d SO2 (.5, 6) suggests that s w e l l i n g and/or e x t r a c t i o n of organic c o n s t i t u e n t s of the shale may a l s o p l a y a r o l e . At t h i s stage, i t i s b e l i e v e d that the f r a c t u r i n g of a p a r t i c u l a r type of o i l shale by l i q u i d S0 i s probably due to a combination of s e v e r a l of these modes. I n i t i a l comparison of the f r a c t u r i n g r e s u l t s obtained v i a 2


36

OIL

SHALE,

TAR

SANDS,

AND

RELATED

MATERIALS

l i q u i d SO2 treatment with those obtained v i a l i q u i d NH3 t r e a t ment might suggest that the d i f f e r e n c e s could be a t t r i b u t e d simply to d i f f e r e n c e s i n the acid/base c h a r a c t e r i s t i c s of the l i q u i d s and the s h a l e s . Further c o n s i d e r a t i o n of the p o s s i b l e mechanisms i n v o l v e d i n l i q u i d SO2 f r a c t u r i n g , however, would suggest such an explanation to be o v e r l y s i m p l i s t i c . E s t a b l i s h ment of f r a c t u r i n g mechanisms f o r these f l u i d s must await the r e s u l t s of f u t u r e experiments. Extracted M a t e r i a l . E x t r a c t s , comprising 2-4% of the o r i g i n a l shale mass, were i s o l a t e d by f i l t e r a t i o n and subsequent evaporation of the l i q u i d SO2 s o l u t i o n s which were i n contact with these s h a l e s . Although no attempt was made to e x t r a c t these shales e x h a u s t i v e l y , i t i s apparent that a p p r e c i a b l y more m a t e r i a l can be e x t r a c t e d by l i q u i d SO2 under r a t h e r mild c o n d i t i o n s . The bulk (90% or more) of the e x t r a c t i s organic although some water i s removed and small amounts of c o l o r l e s s or l i g h t brown c r y s t a l l i n e m a t e r i a l are found i n the cracks and f i s s u r e s of t r e a t e d s h a l e s . I n f r a r e d s p e c t r a (Figures 2-4) of the e x t r a c t r e v e a l s a l i p h a t i c CH and carbonyl groups i n the Green River shale e x t r a c t ; the Moroccan shale e x t r a c t has a s i m i l a r content. These e x t r a c t s represent bitumen p o r t i o n s of the shale. Kerogen f r a c t i o n s , presumably, remain i n the shale; i n f r a r e d s p e c t r a (Figures 2 and 3, Traces B) i n d i c a t e considerable organic content remaining i n the t r e a t e d s h a l e s . The e x t r a c t from the Antrim shale i s somewhat d i f f e r e n t from that of the other two shales i n that both a l i p h a t i c and aromatic C-H but l i t t l e carbonyl i s present (Figure 4C). The aromatic content of t h i s e x t r a c t i s not unexpected s i n c e the organic c o n s t i t u e n t s of Antrim shale are h i g h l y aromatic (Table I ) . Although more d e f i n i t i v e data i s necessary to s u b s t a n t i a t e the p r o p o s i t i o n , i t would appear (Figure 4, A and B) that a s i g n i f i c a n t p o r t i o n of the organic matter i s removed from Antrim shale by treatment w i t h l i q u i d SO2. E x t r a c t s of organic m a t e r i a l were a l s o obtained with other f l u i d s as i n d i c a t e d i n Table I I . Although no d e t a i l e d analyses of these e x t r a c t s were obtained, i t would appear that these e x t r a c t s are of the bitumen f r a c t i o n as expected. Summary P r e l i m i n a r y experiments have demonstrated that l i q u i d SO2 i s e f f e c t i v e i n f r a c t u r i n g and e m b r i t t l i n g both carbonaeceous and s i l i c e o u s o i l s h a l e s . L i q u i d SO2 has advantages over other f l u i d f r a c t u r i n g agents, v i z . , low c o s t , a v a i l a b i l i t y i n q u a n t i t y , and non-petroluem or n a t u r a l gas o r i g i n . Several p o s s i b l e mechanisms f o r shale f r a c t u r i n g have been suggested f o r f u t u r e e x p l o r a t i o n . Organic components can be removed from the shale under mild c o n d i t i o n s . On the b a s i s of these r e s u l t s , f u r t h e r e f f o r t s i n the use of l i q u i d SO2 f o r o i l shale p r o c e s s i n g are j u s t i f i e d . The general a p p l i c a b i l i t y or l i m i t a t i o n s of these procedures


3.

BUROW A N D SHARMA

Fracturing

of

Oil

Shale

37

need to be established; a knowledge of the mechanisms of shale fracturing would aid in this development. Enhancement of organic constituent recovery needs to be explored. Adaptation of these procedures to practical and economical processes in both surface processing and in situ recovery could result. Several of these areas will be discussed in future reports. Acknowledgement s The support of this research by the U. S. Department of Energy under Contract No. ET-78-G-01-3316 is gratefully acknowledged. Provision of o i l shale samples and documentation by Dr. F. P. Miknis (LETC), mineral samples by Dr. W. A. Kneller, preliminary SEM/EDXA results by Dr. S. N. K. Chaudhari, and aid in obtaining the mineral/S02 results by Mr. R. Carter are also gratefully acknowledged.

Literature Cited 1. Perrini, E. M. "Oil from Shale and Tar Sands," Chemical Tech. Rev. No. 51, Noyes Data Corp.: Park Ridge, N. J . , 1975. 2. Yen, T. F. "Shale Oil, Tar Sands, and Related Fuel Sources," Adv. Chem. Series, No. 151, American Chemical Society: Washington, D. C., 1976. 3. Yen, T. F.; Chilingarian, G. V., Dev. Pet. Sci., Vol. 5, Elsevier: Amsterdam, 1976. 4. Matzick, A.; Dannenberg, R. O.; Guthrie, B. "Experiments in Crushing Green River Oil Shale," Bureau of Mines Report No. 5563, 1958. 5. Burow, D. F.; Glavincevski, B. M. "Preprints", Div. of Fuel Chemistry, American Chemical Society, Vol. 25, No. 2, 1980, p. 153. 6. Burow, D. F.; Sharma, R. K. "Liquid Sulfur Dioxide Treatment of Coal," Conf. Chem. Phys. of Coal Utilization, Morgantown, W. Virginia, 1980, Paper T-4. 7. Burow, D. F., In "Chemistry of Non-Aqueous Solvents"; Lagowski, J. J . , Ed.; Academic: New York, 1970, Vol. III, Chapter 2. 8. Yen, T. F.; Chilingarian, G. V. Ref. 3, Chapter 1. 9. Musser, W. N., Dow Chemical Co. Report FE-310, 1976. 10. Miknis, F. P., private communication. 11. Miller, J. F.; Boyer, J. P.; Kent, S. J.; Snyder, M. J. Morgantown Energy Technol. Center, Spec. Publ. (METC/SP-79/6) 1976, 473; Chem. Abstr. 1980, 93, 49920j. RECEIVED

January 19, 1981.


Oil Shale, Tar Sands, and Related Materials - American Chemical

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