Ind. Eng. Chem. Process Des. Dev. 1985, 2 4 , 506-507
506
d 6(
04
08
12
16
20
inlermediele leed concentration ZF
24
I (mole
28
30
% 01 IolUeneI
Figure 8. Comparison of PF, LOF, and SSS configurations (lowpurity products). (Product purities 95%, 90%, 95%). *Ot
NTS = total number of trays in sidestripper F = feed rate, mol/h LS = sidedraw rate, mol/h VS = sidestripper net vapor feed to the main column, mol/h SS = sidestripper bottoms flow rate, mol/h ZFG) = jth component feed composition X S G ) = middle products composition in SS or SSS configuration X L G ) = sidestream stripper liquid feed composition X D l G ) = distillate composition from first column of LOF scheme XD2G) = distillate composition from second column of LOF scheme X S l G ) = bottoms composition from first column of LOF scheme XB2G) = bottoms composition from second column of LOF scheme T B = bottoms product temperature, O F TD = distillate temperature, OF QB = reboiler duty, Btu/h QD = condenser duty, Btu/h QBs = sidestripper reboiler duty, Btu/h TBp = bubble point temperature Tk = temperature at the kth iteration RR = reflux ratio DIAM = column diameter, in. A R = reboiler area, ft2 A D = condenser area, ft2 wt = weighting factor for bubble-point method convergence
Literature Cited
65
010
015
020
Intermedial8 leed concenlmon. Z F
025 ~
030
lmole R loluenel
Figure 9. Comparison of PF, LOF, and SSS configurations (intermediate-purity products). (Product purities 99%, 98%, and 99%).
of the LOF and SSS configurations will be reported in a later paper. Nomenclature NT = total number of trays NF = feed tray N S = tray of sidestream drawoff
Bumingham, D. W.; Otto, F. C. Hydrocarbon Process. 1967, 46. 10. Dryden, C.: Furlow, R. “Chemical Engineering Costs”: The Ohio State University: Columbus, OH, 1966. Doukas, N.; Luyben, W. L. Ind. Eng. Chem. Process Des. D e v . 1976, 17, 272. Elaahl, A.; Luyben, W. L. Ind. Eng. Chem. Rocess Des. D e v . 1983, 22, 80. Holland, C. D. ”Fundamentals of Mukicomponent Distlllatlon”; McGraw-Hill: New York, 1981. Petlyuk, F. B.; Platonov, V. M.; Slavinski, D. M. Int. Cbem. Eng. 1965. 5 , 3 . Seader, J. D. “Mathematical Modeling for Process Design”; AIChE Short Course, Houston, 1981. Tedder, D. W.; Rudd, D. F. AICbE J . 1976, 2 4 , 303. Wang, J. C.; Henke, G. E. Hydrocarbon Process. 1967, 45. 8 .
Department of Chemical Engineering Lehigh University Bethlehem, Pennsylvania 18015
Imad M. Alatiqi William L. Luyben*
Received for review May 23, 1983 Revised manuscript received February 21, 1984 Accepted June 11, 1984
Effect of Raw Oil Shale Grade on the Kinetics of Oxidation of Carbonaceous Residue in Retorted Shale The effect of the grade of raw oil shale on the intrinsic kinetics of oxidation of carbonaceous residue formed during retorting was investigated. The resutts indicate that, within the experlmental uncertainty, the intrinsic reactivity of the carbonaceous residue of Colorado oil shale is independent of orlglnal grade.
In a previous article (Sohn and Kim, 1980), the authors presented the result of an investigation in which the intrinsic kinetics of oxidation of carbonaceous residue in retorted shale were determined. In this communication we discuss the effect of raw oil shale grade on the kinetics of this reaction. All of the experiments reported in the authors’ previous article (Sohn and Kim, 1980) were carried out with samples prepared from a 39.4 gal/short ton oil shale from the Anvil 0196-4305/85/1124-0506$01.50/0
Points Mine in Colorado. In order to determine whether the grade of oil shale has any effect on the kinetics of char oxidation, retorted shales were prepared from oil shale blocks of 57 and 21 gal/short ton from the same source. Samples containing approximately 8% carbonaceous residue were obtained from the former and 3% carbonaceous residue from the latter. The char contents were measured by oxidation at low temperature (
