Assessing the Premature Aging of Chabazite in Natural Gas Drying by TSA

Ongoing research on adsorbent deactivation in drying processes has unveiled crucial insights into the loss of performance with prolonged use. Our study builds on previous work by examining the effects of high temperatures, hydrocarbon exposure, and cycle duration on chabazite adsorbents with a Si/Al ratio of approximately 2 and in the sodium form. By aging the material under controlled conditions, we assessed the impact on its structural and textural properties. Our findings reveal that maintaining high temperatures, coupled with exposure to <i>n</i>-heptane vapor, induces a mild degradation of the crystalline structure, with more pronounced effects during longer aging periods. Notably, hydrocarbons play a critical role in adsorbent deactivation, adsorbing in both the inner pores and the outer surface of the zeolite. This leads to a deterioration of the textural characteristics, which directly correlates with an increase in the carbon content of the bulk material. Additionally, samples exposed to <i>n</i>-heptane vapor exhibited a more homogeneous composition compared to those subjected to manual liquid <i>n</i>-heptane addition. Overall, the degree of degradation varies among aged samples, indicating the need for tailored applications based on specific aging conditions.