Showing papers in "Industrial & Engineering Chemistry Process Design and Development in 1974"

Kinetics of a Moving Boundary Ion-Exchange Process

Abstract: The acid elution of the dark blue cupric ammine complex from a cation-exchange resin produced a sharply defined moving boundary within each bead, which was photographed and measured to provide rate data. 'Analysis of the data by means of a theoretical model indicated that the overall elution process was controlled by a combination of internal and external mass transfer when acid concentrations less than 1.0 N were employed. At these acid concent1'ations the interdiffusion coefficient for the resin phase was found to be 3 X 10-6 cm2/sec, independent of acid concentration but somewhat dependent on particle size. Data collected at· higher acid concentrations were not amenable to analysis by the method employed. The model should be useful for predicting the time required to elute the cupric ammine complex or for designing equipment to carry out this process. Disciplines Catalysis and Reaction Engineering | Complex Fluids | Other Chemical Engineering Comments Reprinted (adapted) with permission from Ind. Eng. Chem. Fundamen., 1974, 13 (1), pp 20–26. Copyright 1974 American Chemical Society. This article is available at Iowa State University Digital Repository: http://lib.dr.iastate.edu/cbe_pubs/278 pin-Tsai equations, the equations become the ordinary \"rule of mixtures,\" that is ·

Nonisothermal Kinetics Studies of the Hydrodesulfurization of Coal

Abstract: Laboratory experiments with 10 bituminous coals were performed to study the nonisothermal kinetics of coal hydrodesulfurization The evolution of hydrogen sulfide during hydrodesulfurization was described by a sulfur release, in order of increasing temperatures, characterized by evolution of the following five sulfur types: Organic I, Organic II, pyrite, sulfide, and Organic III Notable exceptions were the evolution of H/sub 2/S by a process occurring in a temperature range intermediate to the pyrite and sulfide evolution peaks and a higher temperature H/sub 2/S evolution that was not reproducible and may have been an experimental artifact The most important back-reaction of H/sub 2/S with partially desulfurized coal was the inhibition of H/sub 2/S release by iron The reaction orders for sulfur removal in pyrite and Organic III were 05 and 2, respectively, rather than unity The former was rationalized by supposing the existence of an equilibrium between iron pyrite, iron, and adsorbed sulfur as well as a rate-determining step that involves reaction of hydrogen with adsorbed sulfur The latter case with a reaction order of 2 suggests that, in the rate-determining step of sulfur evolution from Organic III, two sulfur-containing species must be involved The Organic III form of sulfur may notmore » be an original component but rather the result of reaction of H/sub 2/S with partially desulfurized coal during hydrodesulfurization« less