Thermodynamics of Cu/ZnO/Al2O3 water-gas shift catalyst poisoning on yellow phosphorus off-gas

Abstract

The thermodynamics of copper-based water-gas shift catalyst for yellow phosphorus off-gas have been calculated according to the thermodynamic theory of heterogeneous reaction systems. The possible chemical reactions and products were analyzed and are discussed here. The results show that AsH 3 and S-containing gaseous impurities (H 2 S, COS, CS 2 , and SO 2 ) in the yellow phosphorus off-gas can preferentially lead to active CuO poisoning of the catalyst, and the poisoning products are Cu 3 As and Cu 2 S. Small amounts of PH 3 and P 4 were the main cause of the inactivation of the anti-toxic component (ZnO) and the support (Al 2 O 3 ) in the catalyst. The inactive products were Zn 3 (PO 4 ) 2 and AlPO 4 , respectively. If yellow phosphorus off-gas is used as the raw material gas for water-gas shift reaction, the As-, S- and P-containing gaseous impurities should be removed to avoid catalyst poisoning.