催化氧化净化黄磷尾气中的磷和硫

Removal of P_4, PH_3 and H_2S from Yellow Phosphoric Tail Gas by a Catalytic Oxidation Process

利用黄磷尾气生产甲酸、乙酸以及甲醇等高附加值产品,净化预处理成为制约其应用的瓶颈问题。研究了用普通活性炭和自制催化剂KU2催化氧化净化黄磷尾气的方法;讨论了固定床系统中常压下、温度2 0～14 0℃,催化剂上磷和硫化氢的吸附特征。KU2和活性炭都能通过催化氧化过程有效脱除黄磷尾气中的P4,PH3和H2 S杂质,随着反应温度和氧含量增加可显著提高净化效果,在最优条件下,经催化氧化净化后的总磷含量<5mg/m3 ,硫化氢含量<5mg/m3 ,失效后的催化剂易于再生,催化剂经多次再生后催化性能恢复良好;提出了活性炭固定床稳定流动吸附过程的数学模型,测得了总传质系数,从实验和理论计算两方面分析讨论了该体系吸附过程的动力行为,模型计算结果与实验测定的穿透曲线吻合良好。

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