失活SCR脱硝催化剂化学清洗再生技术研究

以某燃煤电厂废弃的失活SCR脱硝催化剂为研究对象，用化学清洗方法对其进行再生，以了解化学清洗液有效成分、浓度和液固比等去除脱硝催化剂表面Fe2O3、K2O、Na2O的效果；同时，对再生前后脱硝催化剂的比表面积、孔容和脱硝活性进行了测试，并对比了二者的表面形貌特征。结果表明：硫酸、硝酸对去除催化剂表面中毒元素非常有效，其中硝酸溶液的最佳质量分数为2%；适当增大液固比有利于彻底清洗催化剂表面的中毒元素；经过化学清洗再生后，脱硝催化剂表面变得粗糙，比表面积增大至新催化剂的93.88%，脱硝活性有较大提高，为新催化剂的89%。

Chemical Cleaning Regeneration Technology for Deactivated SCR Catalysts

The regeneration of the deactivated SCR catalysts abandoned by a coal-fired power plant is conducted with the chemical cleaning technology to explore the effects of the effective components concentration of the cleaning solution, and the ratio of liquid to solid on the removal of Fe2O3, K2O and Na2O. Meanwhile, the specific surface area, pore volume and de-NOx activity of the deactivated and regenerated catalysts are also measured, and the surface morphologies of these SCR catalysts are compared. The results show that the sulfuric acid or nitric acid is very effective in removing the poisoning elements, in which the optimum mass concentration of the nitric acid solution is 2%. Increasing the liquid-to-solid ratio adequately is beneficial for completely removing the poisoning elements on the catalyst surface. After the regeneration, the catalyst surface becomes rougher, and the BET result is increased to 93.88% of the new catalyst, which proves that the de-NOx activity of the regenerated catalyst is improved substantially and can be recovered to as much as 89% of the fresh one.