Kinetics of Methyl Iodide Tribosorption on the Solid-Phase Salt KI

Abstract

It was found that the tribosorption of methyl iodide from the gas phase of a closed reactor onto a matrix of KI is described by the rate equation for a reversible first-order reaction v _g – v _{∞, g} = mv _ts ^*exp(–η_td D _sp), where v _g and v _{∞, g} are, respectively, the current and equilibrium amounts of methyl iodide in the gas phase; v _ts ^* is the equilibrium amount of methyl iodide tribosorbed per gram of salt; m is the mass of potassium iodide; η_td is a constant, which characterizes the efficiency of tribodesorption (η_td = 0.011 ± 0.005 g/J); and D _sp is the specific dose of mechanical energy absorbed by the KI powder. The value of v _ts ^* monotonically increased with increasing equilibrium partial pressure of methyl iodide and reached a maximum value of ≈25 μmol/g. The lower limit of the constant η_td , which characterizes the efficiency of tribosorption, was estimated at 0.1 g/J.