Dehydration, Deammoniation and Thermal Stability of Ferrierite

An attempt was made to clarify the adsorption mechanism of partially hydrated and ammoniated ferrierite. The adsorption of CO, CO2, N2, O2, Xe, Kr, Ar, CH4 on the H-ferrierite was investigated as a function of the adsorption temperature. Using equilibrium thermal analyses and adsorption techniques (N2 at 77 K) the dehydration and deammoniation of ferrierite has been studied. Important adsorption variations depending on the pretreatment temperature were observed. The thermal stability of ferrierite was investigated using the adsorption values for N2 at 77 K of pretreated samples. A dehydroxylation and a sintering of the zeolite convert the zeolite into a ‘glass-like’ species at 1173 K, unsuitable for adsorption. The adsorption behaviour of H-ferrierite and H-mordenite LP show only a qualitative analogy; no quantitative relations were observed.