Environ. Sci. Technol. 1987, 21, 490-494
following these pages in the microfilm edition of this volume of the journal. Photocopies of the supplementary material from this paper or microfiche (105 X 148 mm, 24X reduction, negatives) may be obtained from Microforms Office, American Chemical Society, 1155 16th St., N.W., Washington, DC 20036. Full bibliographic citation (journal,title of article, authors names, inclusive pagination, volume number, and issue number) and prepayment, check or money order for $10.00 for photocopy ($12.00 foreign) or $10.00 for microfiche ($11.00 foreign),are required. Registry No. Cl(CH2)20H,107-07-3; C,H5N(CH3),,121-69-7; CCl,COZH, 76-03-9; CCl,, 56-23-5; CHC13,67-66-3; ClCH=CClZ, 79-01-6; CH31, 74-88-4; C6H5N0,,98-95-3; HzOz,7722-84-1.
F.; Gjessing, E. T., Eds.; Ann Arbor Science: Ann Arbor, MI, 1983; pp 107-125. (12) Anbar, M.; Bambenek, M.; Ross, A. B. Natl. Stand. Ref. Data Ser. (US., Natl. Bur. Stand.) 1973, NSRDS-NBS 43. (13) Draper, W. M.; Crosby, D. G. J. Agric. Food Chem. 1983, 31, 734-737. (14) Draper, W. M.; Crosby, D. G. Arch. Enuiron. Contam. Toxicol. 1983. 12. 121-126. (15) Cooper, W.; Zika,'R. G. Science (Washington,D.C.) 1983, 220, 711-712. (16) Gamble, D. S. Can. J. Chem. 1970,48, 2662-2669. (17) Leenheer, J. A.; Noyes, T. I. U S . Geol. Surv. Water-Supply Pap. 1984, No. 2230. (18) Leenheer, J. A.; Brown, P. A.; Noyes, T. I.; Aiken, G.,
Literature Cited Zafiriou, 0. C.; Joussot-Dubien, J.; Zepp, R. G.; Zika, R. G. Environ. Sci. Technol. 1984,18, 358A-371A. Haag, W. R.; Hoign6, J.; Gassman, E.; Braun, A. M. Che-
submitted for publication in Enuiron. Sci. Technol. (19) Fuchs, F.; Raue, B. Vom Wasser 1981, 57, 95-106. (20) Jacques, P.; Braun, A. M. Helv. Chim. Acta 1981, 64, 1800-1806. (21) Frimmel, F. H.; Bauer, H.; Pulzien, J. Murasecco, P.; Braun,
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A. M. Enuiron. Sci. Technol., in press.
Zepp, R. G.; Schlotzhauer,P. F.; Sink, R. M. Environ. Sci.
(22) Moses, F. G.; Lin, R. S. H.; Monroe, B. M. Mol. Photochem. 1969, I, 245-249. (23) Spinks, J. H. T; Woods, R. J. In An Introduction to Ra-
Technol. 1985, 19, 74-81. Haag, W. R.; Hoign6, J. Enuiron. Sci. Technol. 1986, 20, 341-348.
(a) Fischer, A.; Kliger, D.; Winterle, J.; Mill, T. Chemosphere 1985, 14, 1299-1306. (b) Fischer, A.; Kliger, D.; Winterle, J.; Mill, T. In Photochemistry of Environmental Aquatic Systems; Zika, R. G.; Copper, W. J., Eds.; ACS Symposium Series 327; American Chemical Society: Washington, DC, 1987; pp 141-156. Power J. F.; Sharma, D. K.; Langford, C. H.; Bonneau, R.; Joussot-Dubien,J. In Photochemistry of Environmental Aquatic Systems; Zika, R. G.; Cooper, W. J., Eds.; ACS Symposium Series 327; American Chemical Society: Washington, DC, 1987; pp 157-173. Swallow, A. J. Nature (London)1969,222, 369-370. Joschek, H.; Grossweiner, L. I. J. Am. Chem. SOC.1966,88,
diation Chemistry,2nd ed.; Wiley-Interscience: New York, 1976. (24) Kohler, G.; Getoff, N.; Rotkiewicz, K.; Grabowski, Z. R. J. Photochem. 1985,28, 537-546. (25) Farhatazis; Ross, A. B. Natl. Stand. Ref. Data Ser. ( U S . Natl. Bur. Stand.) 1977, NSRDS-NBS 59. (26) Lachish, U.; Ottolenghi, M.; Stein, G. Chem. Phys. Lett. 1977,48, 402-406. (27) Dulin, D.; Mill, T. Environ. Sci. Technol. 1982, 16, 815. (28) Zepp, R. G.; Schlotzhauer,P. F. Environ. Sci. Technol. 1983, 17,462-468. (29) Sturzenegger, V.; Hoign6, J., Swiss Federal Institute for
Water Resources and Water Pollution Control, Dubendorf, Switzerland, personal communication, 1987.
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Grabner, G.; Kohler, G.; Zeehner, J.; Getoff, N. Photochem. Photobiol. 1977, 26, 449-458. Kohler, G.; Solar, S.;Getoff, N.; Holzwarth, A. R.; Schaffner, K. J. Photochem. 1985,28, 383-391. Reuter, J. H.; Ghosal, M.; Chian, E. S. K.; Giabbai, M. In Aquatic and Terrestrial Humic Materials; Christman, R.
Received for review August 25,1986. Accepted February 5,1987. Financial support from the President o f the Swiss Federal Institutes of Technology is acknowledged. Mention of trade names or commercial products does not constitute endorsement by the U S . Environmental Protection Agency.
Trace Element Partitioning during the Retorting of Julia Creek Oil Shale John H. Patterson,* Leslie S. Dale, and James F. Chapman CSIRO, Division of Energy Chemistry, Lucas Heights Research Laboratories, Menai, N.S.W., 2234 Australia
A bulk sample of oil shale from the Julia Creek deposit in Queensland was retorted under Fischer assay conditions at temperatures ranging from 250 to 550 "C. The distributions of the trace elements detected in the shale oil and retort water were determined a t each temperature. Oil distillation commenced at 300 "C and was essentially complete at 500 "C. A number of trace elements were progressively mobilized with increasing retort temperature up to 450 "C. The following trace elements partitioned mainly to the oil: vanadium, arsenic, selenium, iron, nickel, titanium, copper, cobalt, and aluminum. Elements that also partitioned to the retort waters included arsenic, selenium, chlorine, and bromine. Element mobilization is considered to be caused by the volatilization of organometallic compounds, sulfide minerals, and sodium halides present in the oil shale. The results have important implications for shale oil refining and for the disposal of retort waters. Introduction Oil shales often contain relatively high concentrations 490
Environ. Sci. Technol., Vol.
21, No. 5, 1987
of some trace elements that may pose occupational health and environmental pollution problems during processing. The mobilization of trace elements and their distribution during oil shale retorting are therefore important in processing studies, and a number of partitioning studies have been carried out on the retorting of Green River Formation (2-4) and Australian (5) oil shales. The Julia Creek deposit in Queensland, Australia, contains a number of trace elements that are potentially hazardous to the environment and to occupational health. These elements include arsenic, selenium, molybdenum, cadmium, thallium, and uranium (6);those of interest to shale oil refining include vanadium, nickel, iron, and arsenic (5). Preliminary trace element partitioning studies (5) have revealed significant mobilization of arsenic and selenium during retorting under Fischer assay conditions. Subsequently, a definitive study was undertaken of the geochemistry and mineralogical residences of a comprehensive range of trace elements in this oil shale (6). This work, and the availability of a more representative composite sample, provided a favorable opportunity to extend
0013-936X/87/0921-0490$01.50/0
0 1987 American Chemical Society
Table I. Fischer Assay Yields at Different Retort Temperatures yields, g/lOO g of shale retort temp, "C
spent shale
oil
250 305 350 405 450 50OU 550
97.6 97.3 95.8 90.1 87.5 86.9 f 0.06 86.0
nil 0.10 0.91 5.3 6.93 7.40 f 0.04 7.59
a
water
gas and losses
0.1 2.3 2.4 0.2 0.77 2.52 1.68 2.92 2.51 3.06 3.05 f 0.05 2.65 f 0.05 3.23 3.18
Yields at 500 "C are the average of three runs.
earlier work on trace element partitioning and to examine the effects of retort temperature on the mobilization of trace elements.
Experimental Section The general Fischer assay procedure used was as described in ASTM D3904-80. However, two modifications were made to ensure maximum oil recovery in the receiver. First, the ice-water bath was replaced with an alcohol-dry ice bath maintained a t -20 OC, to minimize losses of oil in the retort gas. Second, a glass-to-metal seal was used to enable the collection vessel to be mounted almost directly onto the block. This minimized losses of oil due to condensation in the normal outlet pipe. For retorting at different temperatures, the standard heating rate of 12 deg/min was used up to the required temperature; the retort was held a t this temperature for 40 min. The oil was separated from the retort water within 1h of retorting. Unfiltered subsamples of the oil and retort water were taken the same day for neutron activation analysis. The balance of the oil and water were stored in glass bottles a t room temperature and -18 OC, respectively, prior to other analyses. Solids carry-over was minimal as indicated by low calcium (the major element in the shale) contents of the oils and as expected from the Fischer assay studies of Wildeman and Meglen (4). Raw shales, spent shales, oils, and retort waters were analyzed by a variety of methods, including instrumental neutron activation analysis (INAA), inductively coupled plasma atomic emission spectrometry (ICPAES), and at-
omic absorption spectrometry; these methods have been described elsewhere (5). To investigate the occurrence of metal-organic compounds, the raw shale sample was soxhlet extracted sequentially with benzene, chloroform, and finally methanol. Each extraction was continued until no color was visible. The extracts were analyzed for trace elements by INAA and ICPAES. This work was carried out on a whole-of-seam composite sample, which was prepared from core samples from a stratigraphic reference hole, located close to CSR Limited's bulk sampling site near the township of Julia Creek. The composite sample was crushed to -5.6 mm and blended before riffling into separate batches for retorting. The composite sample has been characterized in detail (6).
Results and Discussion Yields of oil, retort water, and spent shale at the various retort temperatures are shown in Table I. The agreement between triplicate runs at 500 "C was good. Under Fischer assay conditions, oil distillation commenced at 300 OC and was nearly complete a t 500 "C. Most of the retort water was already liberated at 250 OC, but a small amount'was formed during pyrolysis between 300 and 450 OC. Gas formation commenced a t about 300 OC and reached a plateau at 450-500 OC before increasing slightly at 550 "C. Chemical analyses of the raw and spent shales were carried out for a wide range of major and trace elements. The concentrations of the significant trace elements in the oil shale and the percentage that remained in the retorted shale are given in Table 11. Most trace elements remained substantially, if not completely, in the retorted shale. However, since in most cases the results are based on the difference between two similar values, it is difficult to establish reliably small elemental losses. Elements that were significantly mobilized during retorting on the basis of analyses of oils and waters (Tables I11 and IV) include mercury, arsenic, selenium, chlorine, and bromine. The results are similar to those reported for Green River Formation oil shales (1-3). While gas analyses were not carried out in this study, other workers have shown that most of the mercury ( 2 , 3 )is partitioned to the gas phase. Within experimental errors, the element percentage remaining in the spent shale (Table 11) is also the elemental closure percentage except for arsenic and selenium. The
Table 11. Percentage of Element Remaining in Spent Shale at Different Retort Temperatures
element
F Na A1
c1
Ti V Fe
co
Ni cu Zn As Se Br Mo Cd Sb Hg U
shale concn, Pglg 650 3 700 22 000 800 1200 2 000 16 000 9 160 110 800 50 30 6 270 25 18 0.4 30
retort temperature, "C 250
305
350
118 98 94 b 97 96 90 87 96 98 98 88 95 100 105 93
b 99 105 b b 95 90 91 b b b 99 85 92 b 84 95 b 113
b 96 96 b b 95 88 81 b b b 89 81 81 b 99 88 14 105
100
25 114
405
450
500'
550
93 96 97 b 100 97 98 84 98 96 97 88 83 96 102 77 107
90 95 96 b 102 98 95 84 100 98 97 75 79 92
105 98 f 2.5 99 iz 9 96 f 5 98 f 2 95 f 3 96 f 3 88 f 9 95 f 1.5 95 k 2 95 f 6 92 f 4 89 f 8 101 f 5 100 i 1.5 70 94 f 4 6 105 i 17
95 94 92 b 92 95 98 118 93 93 91 83
