Regeneration of Selective Catalyst Reduction Catalysts Deactivated by Pb, As, and Alkali Metals

Abstract

Owing to increased operating time and Pb, As, and alkali metal poisoning of a catalyst, the activity of the catalyst is lowered. In the present study, we utilized the acetic acid and the traditional sulfuric acid pickling process for regeneration and then performed Brunauer-Emmett-Teller (BET) specific surface area, denitrification efficiency, scanning electron microscopy, and X-ray fluorescence (XRF) analysis of a fresh catalyst, a deactivated catalyst, and a regenerated catalyst for comparison purposes. The experimental results demonstrated that the removal ratios of Pb, As, Na, and K were 99.2, 98.8, 99.9, and 93.9%, respectively. Compared to the traditional sulfuric acid regeneration technology, the acetic acid regeneration technology eliminates the activated liquid immersion step; therefore, the steps are simpler and efficient for the regeneration of selective catalyst reduction catalysts deactivated by Pb, As, and alkali. The current study provides a new method for the regeneration and application of selective catalyst reduction (SCR) catalysts, which is particularly applicable for regenerating a large number of Pb, As, and alkali-metal poisoned catalysts.