铂耗和氨耗是硝酸生产的主要技术指标。在流动氧气氛模拟条件下,以及800~950℃的硝酸生产实际氨氧化环境中,Pt-Rh二元和Pt-Pd-Rh三元合金及其催化网的失重和铂耗均遵循相同的模式,即ΔW/S=Kt2/3与ΨΣ=K't2/3。工厂实际测定数据表明...铂耗和氨耗是硝酸生产的主要技术指标。在流动氧气氛模拟条件下,以及800~950℃的硝酸生产实际氨氧化环境中,Pt-Rh二元和Pt-Pd-Rh三元合金及其催化网的失重和铂耗均遵循相同的模式,即ΔW/S=Kt2/3与ΨΣ=K't2/3。工厂实际测定数据表明,在常压氨氧化法生产硝酸过程中,Pt-12Pd-3.5Rh合金催化网的铂耗为0.044 g Pt/t(HNO3),比Pt-4Pd-3.5Rh合金催化网的铂耗(0.061g Pt/t(HNO3))低28%;在中压氨氧化法生产硝酸过程中,Pt-12Pd-3.5Rh合金催化网的铂耗为0.121g Pt/t(HNO3),比Pt-5Rh和Pt-10Rh合金催化网的铂耗(0.15~0.153 g Pt/t(HNO3))低21%,而其氨耗比后者降低3%~7%。研究结果证明,在Pt-Rh合金中添加钯或在Pt-Pd-Rh合金中增加钯含量明显降低催化合金的铂耗。展开更多
The effects of BaO doping on the three-way catalytic activity of Pt-Rh catalyst and on water-gas shift were investigated. The results show that the light-off temperatures of hydrocarbon and carbon monoxide and nitroge...The effects of BaO doping on the three-way catalytic activity of Pt-Rh catalyst and on water-gas shift were investigated. The results show that the light-off temperatures of hydrocarbon and carbon monoxide and nitrogen oxides of the fresh catalysts slightly differ from those of the aged catalysts, and the catalysts containing CeO2-ZrO2-BaO have lower lightoff temperature and better catalytic activity than these containing BaO and CeO2-ZrO2 after hydrothermal aging for 5 h at 1000 ℃. The catalysts were characterized by means of the temperature-programmed reduction （TPR） in hydrogen and the temperature-programmed desorption （TPD） in oxygen. It is confirmed that the suggested route of CeO2-ZrO2-BaO by coprecipitation can improve the catalytic activity of catalysts.展开更多
The numerical simulation for temperature distribution of Pt-Rh alloy bushing was carried out using a thermal-electric module in ANSYS Workbench finite element analysis software.The effects of side wall thickness,plug ...The numerical simulation for temperature distribution of Pt-Rh alloy bushing was carried out using a thermal-electric module in ANSYS Workbench finite element analysis software.The effects of side wall thickness,plug thickness,the angle of two side walls and electrode structure on the uniformity of temperature distribution were investigated.Meanwhile,the contrastive analysis results of bushing with and without glass melt were discussed.The simulation results show that,when the homogeneous glass melt flows through bushing,the temperature difference between the center and both ends of bushing is decreased significantly,but the temperature distribution at both ends of bushing is still affected by heating non-uniformity of bushing.Compared with side wall thickness,plug thickness and the angle of two side walls,electrode structure plays a greater role in adjusting heating uniformity of bushing.展开更多
文摘铂耗和氨耗是硝酸生产的主要技术指标。在流动氧气氛模拟条件下,以及800~950℃的硝酸生产实际氨氧化环境中,Pt-Rh二元和Pt-Pd-Rh三元合金及其催化网的失重和铂耗均遵循相同的模式,即ΔW/S=Kt2/3与ΨΣ=K't2/3。工厂实际测定数据表明,在常压氨氧化法生产硝酸过程中,Pt-12Pd-3.5Rh合金催化网的铂耗为0.044 g Pt/t(HNO3),比Pt-4Pd-3.5Rh合金催化网的铂耗(0.061g Pt/t(HNO3))低28%;在中压氨氧化法生产硝酸过程中,Pt-12Pd-3.5Rh合金催化网的铂耗为0.121g Pt/t(HNO3),比Pt-5Rh和Pt-10Rh合金催化网的铂耗(0.15~0.153 g Pt/t(HNO3))低21%,而其氨耗比后者降低3%~7%。研究结果证明,在Pt-Rh合金中添加钯或在Pt-Pd-Rh合金中增加钯含量明显降低催化合金的铂耗。
基金Project supported by the National Natural Science Foundation of China (20273043) the National Nature Science KeyFoundation of China (20333030)
文摘The effects of BaO doping on the three-way catalytic activity of Pt-Rh catalyst and on water-gas shift were investigated. The results show that the light-off temperatures of hydrocarbon and carbon monoxide and nitrogen oxides of the fresh catalysts slightly differ from those of the aged catalysts, and the catalysts containing CeO2-ZrO2-BaO have lower lightoff temperature and better catalytic activity than these containing BaO and CeO2-ZrO2 after hydrothermal aging for 5 h at 1000 ℃. The catalysts were characterized by means of the temperature-programmed reduction （TPR） in hydrogen and the temperature-programmed desorption （TPD） in oxygen. It is confirmed that the suggested route of CeO2-ZrO2-BaO by coprecipitation can improve the catalytic activity of catalysts.
基金Funded by the State Key Laboratory of Silicate Materials for Architectures(Wuhan University of Technology)(No.SYSJJ2019-21)the National Key Research and Development Program of China(No.2016YFB0303700)。
文摘The numerical simulation for temperature distribution of Pt-Rh alloy bushing was carried out using a thermal-electric module in ANSYS Workbench finite element analysis software.The effects of side wall thickness,plug thickness,the angle of two side walls and electrode structure on the uniformity of temperature distribution were investigated.Meanwhile,the contrastive analysis results of bushing with and without glass melt were discussed.The simulation results show that,when the homogeneous glass melt flows through bushing,the temperature difference between the center and both ends of bushing is decreased significantly,but the temperature distribution at both ends of bushing is still affected by heating non-uniformity of bushing.Compared with side wall thickness,plug thickness and the angle of two side walls,electrode structure plays a greater role in adjusting heating uniformity of bushing.
