氨厂低变催化剂活性下降原因分析

Analysis for the Activity Decline of Low Temperature Shift Catalyst in An Ammonia Plant

大庆石化公司合成氨装置的低温变换催化剂(B204)在工业应用了3年后活性下降,反应器出口CO浓度增高。为了找出活性下降的原因,分析了催化剂的组成,并对催化剂的积碳量和结构进行表征。结果表明,催化剂活性下降的主要原因是催化剂的活性组分铜晶粒度增大、比表面积降低和孔分布变窄。

The catalytic activity of the low temperature shift catalyst （B204） used in the ammonia plant of Daqing Petrochemical Co. declined and the concentration of CO increased in the outlet of reactor after onstream three years. In order to found the causes of activity decline of the catalyst, the components of the fresh-and used catalysts were analyzed ,and the deposited carbon amount and structure of the catalysts were characterized. The results showed that the main reasons causing catalytic activity decline were the crystallite size increase of the active component Cu, specific surface area reduction and pore distribution becoming narrow.