Kinetics of corrosive sulfur adsorption in transformer oil with Ag-Y, Ce-Y and Cu-Y zeolites

摘要

Ag-Y, Ce-Y, and Cu-Y zeolites were successfully prepared via the liquid phase ion exchange method as adsorbents for removing dibenzyl disulfide and dodecyl mercaptan in transformer insulating oil. The physicochemical properties of the adsorbents were investigated by X-ray diffraction, X-ray fluorescence, and N-2 adsorption-desorption. The removal efficiency increased rapidly with increased dosage of Ag-Y (0.5-1.0 wt%) and Ce-Y, Cu-Y (1.0-3.0 wt%), and became slower with its increased dosage. Kinetic studies showed the adsorption on these adsorbents can be described by a pseudo-second-order model, and the rate constants increased with increasing temperature, indicating the endothermic nature of the adsorption. The activation energies (E-a) calculated for dibenzyl disulfide and dodecyl mercaptan were over 40 kJ mol(-1) which clearly indicated that the adsorption process on the three adsorbents was dominated by chemical adsorption.