Daniel D. Perlmutter
Chemical and Biomolecular Engineering
The kinetics of the reactions of gases with solids are intimately related to the pore structure of the solid; however, this structure is dynamic and changes as the solid reacts and is transformed into reaction products. The result of the structureal change in the solid is a feedback effect in which the chemical and porosity effects reinforce each other.
The study of such reactions involves simultaneous considerations of chemical rates of reaction and structural change in the solid. Experimental data is needed on global rates at various conversions. The interpretation of such measurements calls for analytic models and their numerical solutions, especially to highlight critical values of parameters that produce maxima in rates or conversions.
Realistic modeling of gas-solid reaction systems must allow for gaseous products as well as for the possible deposition of solid products. In the latter case, diffusion through solid layers adds an additional complication to the overall mechanism. For this purpose, random pore models have been successful in interpreting a wide range of observations in gas-solid systems related to environmental and energy problems. Specific applications have been made to coal char gasification, to removal of pollutant SOx via reaction with lime, and to dehydration of inorganic salt hydrates.
In many cases, porous solids contain significant void regions that are initially inaccessible to gaseous reactants, but become increasingly accessible in the course of reaction. A model has also been developed to account for the existence of this hidden porosity.
Removing Traces of Polar Hydrocarbons from Liquids
Removal of trace components from liquid hydrocarbons is needed to meet stringent specifications that insure long catalyst lifetimes, efficient processing performance, and high product quality, especially for products that are polymer precursors. Zeolites offer the advantages of easy separation and recovery and hence play an increasingly important role as adsorbents in this application. Knowledge of fundamental adsorption parameters and the role of zeolite property parameters are essential for rapid progress in this area.
A representative study deals with removal of acetonitrile, acrylonitrile, or dioxane from toluene. The selection of zeolites was made to allow the study of effects of varying aluminum content, presence and absence of acidic centers, and varying pore volumes. To assess the relative effectiveness of each adsorbent, both equilibrium and continuous flow pseudo-equilibrium breakthrough experiments are being conducted.
B.S., Chemical Engineering, New York University, 1952
Ph.D., Chemical Engineering, Yale University, 1956
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