Study of the properties of adsorption of SO₂ – thermal regeneration cycle of activated coke modified by oxidization

Abstract

BACKGROUND In order to clarify the effect of thermal regeneration on the desulfurization performance of activated coke, consecutive adsorption of SO2–thermal regeneration cycle experiments were carried out under different thermal conditions in this study. RESULTS Results showed that the decrease in breakthrough sulfur capacity was not very significant for the cokes except for the first regeneration cycles. From 400–600 °C, the higher the regeneration temperature was, the better the desulfurization activity of the cokes after regeneration. Various means (FT‐IR, BET, XPS, TGA, SEM and in situ DRIFTS) were used to characterize samples. The results indicated that the desulfurization products were divided into physisorbed SO2, H2SO4 and sulfate. The phenolic hydroxyl and carboxyl groups on the surface of activated cokes promoted the removal of SO2. CONCLUSION The deposition of sulfate resulted in a significant decrease in the sulfur capacity of activated coke after the first two regeneration cycles. However, the residual amount of sulfate on the activated coke after regeneration declined with increasing regeneration temperature. Moreover, the phenolic hydroxyl and carboxyl groups did not disappear after regeneration, resulting in the desulfurization activity of cokes remaining relatively stable during subsequent desulfurization cycles. © 2017 Society of Chemical Industry

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