REGENERATION OF SOLID CATALYSTS: EVALUATING THE EFFICIENCY OF SYSTEMIC THERMAL RECOVERY BASED ON STRUCTURAL-ACTIVITY CRITERIA

Abstract

This article evaluates the response of a Co-Mo/γ-Al2O3 type solid catalyst used in industrial hydrotreating processes to various thermal regeneration conditions using structural-activity criteria. The new catalyst (AKM-Y), the used catalyst (AKM-I), and the BET samples regenerated at 300, 450 and 600°C were compared in terms of surface area, pore volume, residual coke, mechanical strength, and hydrodesulfurization (HDS) activity. It was shown that the accumulation of coke in the used catalyst up to 10.8% by mass reduces the surface area of BET from 238 to 104 m2/g, and the activity of HDS from 97.5 to 43.0%. Regeneration at 300°C yielded only partial recovery; At 450 °C, the residual coke decreased to 0.9 wt.%, the BET surface area reached 211 m2/g, and the HDS activity reached 82.0%. Although residual coke decreased to 0.3 wt.% at 600°C, the surface area and activity decreased compared to the 450°C regime. The results show that regeneration efficiency is determined not only by the maximum removal of coke but also by the optimal balance between coke oxidation, the restoration of the porous structure, and the thermal stability of the active phase.