The prediction of multicomponent adsorption equilibria from single-componen
t data is one of the most challenging and important problems in adsorption.
The chief obstacle to progress is a scarcity of accurate and consistent ex
perimental data over a wide range of temperature and loading for testing th
eories. Several binaries and one ternary system on two types of zeolites (s
ilicalite and faujasite) were studied in a combination calorimeter-volumetr
ic apparatus. Activity coefficients and excess functions for enthalpy, free
energy, and entropy were extracted from the binary data using a three-cons
tant equation to represent nonidealities. The successful correlation of bin
ary excess functions with pure-component properties for type I isotherms on
zeolites is a first step toward predicting multicomponent adsorption from
single-gas adsorption and a major advancement over the theory of ideal adso
rbed solutions.