Dynamic adsorption of ammonia: apparatus, testing conditions, and adsorption capacities

作者：Amid Hooman; Maze Benoit; Flickinger Michael C; Pourdeyhimi Behnam

来源：Measurement Science and Technology, 2017, 28(5): 055901.

DOI：10.1088/1361-6501/aa6236

• Adsorption capacity/breakthrough
• ammonia
• activated carbon
• test methods
• gas detector

There is a growing need for adsorbents with high capacities for adsorption of toxic gas molecules. Methods and conditions to test these materials introduce large discrepancies and overestimates (similar to 90%) in the reported literature. This study describes a simple apparatus utilizing hand-held inexpensive gas sensors for testing adsorbents and hybrid adsorbent materials, explains possible sources for the observed discrepancies based on how the measurements are made, and provides guidelines for accurate measurements of adsorption capacity. Ammonia was the model gas and Ammonasorb T activated carbon was the model commercial adsorbent. Inlet ammonia concentration, residence time, adsorbent pre-treatment (baking) and humidity, affected the measured adsorption capacities. Results suggest that the time lag in gas detection sensors leads to overestimated capacities. Monitoring both inlet and outlet concentrations using two calibrated sensors solved this issue. There was a direct relationship between adsorption capacity and residence time and capacities were higher at higher inlet concentrations. The size of the adsorbent particles did not show a significant effect on adsorption breakthrough, and the apparatus was able to quantify how humidity reduced the adsorption capacity.

• 出版日期2017-5