摘要
【目的】分析表征热失活过程中钒催化剂的孔径变化情况,及在410℃、440℃、480℃、520℃下SO2转化为SO3的转化率、活性变化趋势,并分析其微观结构的变化情况。【方法】通过钒催化剂的耐热试验,用SEM扫描电镜来观察热失活钒催化剂的微观表面结构变化过程,并对热失活过程中钒催化剂进行孔径分析及转化率活性检测。【结果】随着热失活过程的进行,钒催化剂的孔径明显向大孔方向移动,钒催化剂转化率逐渐降低。在测试温度范围内,催化剂的活性衰减率总体呈现出由慢到快的趋势,在测试温度为410℃、480℃、520℃时,活性衰减率都是先降低后增加。在440℃时,随着热失活过程的增加,活性衰减速率不断增加。【结论】随着耐热时长的增加,热失活现象明显,孔径向大孔方向移动,钒催化在被使用过程中,气体扩散速率发生变化,转化率下降,造成钒催化剂活性大幅度衰减,活性成分及金属助剂在耐热过程中逐渐被熔融,导致钒催化剂的使用寿命变短。
[Purposes]The change of pore size of vanadium catalyst during thermal deactivation was analyzed,and the conversion rate and activity change trend of SO2 to SO3 at 410℃,440℃,480℃ and 520℃ were analyzed,and the change of microstructure was analyzed.[Methods]Through the heat resistance test of vanadium catalyst,the microscopic surface structure change process of thermally deactivated vanadium catalyst was observed by SEM scanning electron microscope,and the pore size analysis and conversion activity detection of vanadium catalyst in the process of thermal deactivation were carried out.[Findings]With the thermal deactivation process,the pore size of the vanadium catalyst obviously moved to the large pore direction,and the conversion rate of the vanadium catalyst gradually decreased.In the test temperature range,the activity decay rate of the catalyst generally shows a trend from slow to fast.When the test temperature is 410℃,480℃,and 520℃,the activity decay rate decreases first and then increases.At 440℃,the activity decay rate increases with the increase of thermal deactivation process.[Conclusions]With the increase of heat resistance time,the thermal deactivation phenomenon is obvious,and the pore size moves to the macropore direction.During the use of vanadium catalyst,the gas diffusion rate changes,and the conversion rate decreases,resulting in a significant decrease in the activity of vanadium catalyst.The active components and metal promoters are gradually melted6 during the heat-resistant process,resulting in a shorter service life of the vanadium catalyst.
作者
陈切
刘应炜
CHEN Qie;LIU Yingwei(Catalyst Research and Development Center of Guizhou Wylton Catalyst Technology Limited Company,Tongren 554300,China)
出处
《河南科技》
2024年第1期76-79,共4页
Henan Science and Technology
关键词
钒催化剂
热失活过程
活性衰减率
催化性能
vanadium catalyst
thermal deactivation process
activity decay rate
catalytic performance
