Removal of P4, PH3 and H2S from Yellow Phosphoric Tail Gas by a Catalytic Oxidation Process

Yellow phosphorus tail gas is a resource used to produce bulk chemicals, such as formates, oxalates, and methanol after its pretreatment and purification. In this study, catalytic oxidation of phosphorus and hydrogen sulfide in yellow phosphorus tail gas was investigated on an ordinary activated carbon (OAC) and a home made catalyst KU2. The adsorption characteristics of phosphorus and hydrogen sulfide on the catalysts were studied in a fixed-bed system at different temperatures between 20℃ and 140℃ at atmospheric pressure. Both KU2 and OAC are proved to be effective catalysts in the catalytic oxidation process (COP) for H 2S and PH 3 removal. Purification efficiency increased with the increase of temperature and oxygen concentration in yellow phosphorus tail gases. Under optimized operation conditions, the product gases with a content of hydrogen sulfide<5 mg/m 3 and total phosphorus<5 mg/m 3 were obtained by using the COP process. Deactivated catalysts could be restored to the original activated state, even after several regenerations. A mathematical model was developed to simulate the experimental results and the mass transport coefficient from the experiment was evaluated. Good agreement between the experimental breakthrough curves and the model predictions was observed.