Measurement and interpretation of zeolite NaA builder performance

Abstract

AbstractIon exchange isotherms are commonly used to describe the distribution of ions between a solid and liquid phase under equilibrium conditions. In the detergent industry, the Ca‐Na‐zeolite A isotherm can be utilized to determine the builder performance of zeolite NaA under a specific set of experimental conditions. In this paper, we demonstrate how the Ca‐Na‐zeolite A isotherm is developed and utilized in measuring and interpreting the calcium exchange capacity score of zeolite NaA. Owing to the large number of testing parameters that affect the equilibrium distribution of calcium between the zeolite and solution phases, and hence the calcium exchange capacity score of the zeolite, a recommendation is made as to a standard set of test conditions that provide for both analytical precision and convenience. With this approach, builder performance differences between any two zeolites can then easily be measured and assessed. As an extension to the isotherm principles developed in this paper, the prediction of zeolite performance in real detergent systems is illustrated. Particular attention is given to the more efficient utilization of the ion exchange capacity of zeolite NaA by the recently developed concentrated detergent systems.