A Jäntti Approach for Quick Calculations of Sorption Equilibria

Abstract

Adsorption / Sorption / Multilayer / Kinetics / Fast MeasurementJäntti introduced a method to calculate the adsorption equilibrium by measuring the actual adsorbed amount three times after a change to the gas pressure. He successfully applied the method to gas/solid systems in which simple adsorption processes occur. In the present paper we discuss a more general approach for different modes of measurement (adsorption and desorption), including sorption processes obeying second order differential equations.

Characterization of the Micro-Structure of Rice Starch

“…The Jäntti approach results in a reduction of the time required for measurements. The first nine series of adsorption measurements were considered and it is estimated that by applying the Jäntti method, the result should be obtained in less the half the time than measured otherwise (Poulis et al 2002b). …”

“…To shorten the measurement time, an extrapolation method first described by Jäntti (Jäntti et al 1970(Jäntti et al , 1972Jäntti and Robens 1981) and extended by Poulis et al was applied (Massen et al 2000;Poulis et al 2002aPoulis et al , 2004Poulis et al , 2006Poulis et al , 2007. In this method, it is assumed that after setting a particular gas pressure, uptake or release follows a simple exponential law.…”

Methods of humidity determination Part II: Determination of material humidity

“…Therefore often the measuring procedure will be shortened not waiting for equilibrium conditions. To speed up measurements and to avoid errors an extrapolation method should be applied as described in [15][16][17].…”

Introduction of new functions to speed up sorption measurements

“…One step further is the possibility that a more complicated molecular model is available and that it allows the possibility to predict the function J (t). Such a predicted function will generally contain parameters (Poulis et al, 2002(Poulis et al, , 2004. Comparison with the measured results can lead to estimation of the values of those parameters.…”