(258f) Adsorption of Organic Iodides from Vessel Off-Gas (VOG) Streams on Silver-Containing Adsorbents
AIChE Annual Meeting
Tuesday, November 17, 2020 - 9:00am to 9:15am
Furthermore, to understand the adsorption kinetics, 113, 266, 1130 and 10400 ppbv CH3I adsorption experiments on Ag0-Aerogel at 150 oC were performed. A core-shrinking process was observed, and the corresponding shrinking core model was applied to determine the reaction rate constant and CH3I pore diffusivity in Ag0-Aerogel. A constant pore diffusivity was calculated to be approximately 4.59 ± 0.10 ×10-4 cm2/s. The determined reaction rate constants were changing with CH3I concentration, indicating a possible non-1st order reaction. Therefore, the shrinking core model was modified and we found the reaction order is approximately 1.37. To understand the rate-determine step, the contributions of multiple physical and chemical processes in the adsorption were calculated. The results show that the adsorption process is overall controlled by pore diffusion, but at low concentration, the reaction between CH3I and silver particles is more significant and the adsorption process can be reduced to a surface reaction at low concentrations in a relatively short period (in at least one year for 113 ppbv compared with equilibrium time of more than 50 years).