Ind. Eng. Chem. Process Des. Dev., Vol. 20, No. 1, 1981
In the further study made of this process it was concluded that the performance benefits to be expected for the double-annulus reactor did not warrant the increased reactor complexity and cost. Different conclusions might have been reached for a different reaction system or a light source with different emission characteristics. The conditions which could be expected to result in a more significant performance improvement would be a small optical thickness (ncl),i.e., small weighted absorptivity, low concentrations, and small radiation path lengths. A system for which the weighted molar absorptivity of the product was larger than that of the reacting species could also be expected to benefit from a double-annulus reactor. Acknowledgment Partial support for this study provided by the Technion Foundation for Research and Development is gratefully acknowledged. Nomenclature c = concentration of absorbing or reacting species ci = initial reactant concentration
c1 = reactant species concentration Z, = incident light intensity at reactor wall, einstein/s cm2 Zo = incident light intensity, outer annulus, einstein/s cm2 rl = inner annular radius r2 = outer annular radius a = average linear velocity z = length along reactor
Greek Letters cyx
= molar absorptivity, L/mol cm
a = weighted average for cyA X = wavelength
Literature Cited Atlas, H.; Hasson, D.; Rubin, M. B.; Resnick, W. Ind. Eng. Chem. Process Des. Dev. 1978, 75, 68. Calvert, J. G.; Pitts, J. N. ”Photochemistry”,W h y : New York, 1966.
Department of Chemical Engineering Technion-Zsrael Institute of Technology Haifa, Israel
Ilana Bilgory William Resnick*
Received for reuiew November 5, 1979 Accepted September 24, 1980
CORRECTIONS Experimental Study of Copper Extraction with LM-64N by Means of Motionless Mixers, J. C. Merchuk, R. Shai, and D. Wolf, Ind. Eng. Chem. Process Des. Dev. 1980,19, 91. Page 97. There is an error in eq A-3. It should read
Simple Conversion Relationships for Noncatalytic Gas-Solid Reactions, H. H. Lee, Ind. Eng. Chem. Process Des. Dev. 1980, 19, 242. Page 243. Equation 4b should read P@M& Y= P&&l
175
-
4
Page 244. The sentence right after eq 17, “If the pores shrink ...” should read: “The expression for C#I is also applicable to the case of shrinking pores”. Adsorption of Methane, Ethane, and Ethylene Gases and Their Binary and Ternary Mixtures and Carbon Dioxide on Activated Carbon at 212-301 K and Pressures to 35 Atomspheres, R. Reich, W. T. Ziegler, and K. A. Rogers, Znd. Eng. Chem. Process Des. Dev. 1980, 19, 336. Page 342. In the first and second paragraphs, 5-60 and 5-40 cal/cm3 should read 5-60 X lo3 and 5-40 X lo3 cal/cm3. Page 342. The first line under Gas Mixtures should read, “The characteristic curve, eq 15, etc.” Page 342. The abscissa of Figure 2 should read RT/ V8(Tnbp)In x i f , / f i as in eq 15. The xi was omitted by mistake. Page 343. In the last paragraph, 60 cal/cm3 should read 60 X lo3 cal/cm3.
