To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content ...To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content in coal)catalysts were prepared by the incipient wetness impregnation method,followed by acid washing to remove calcium-containing minerals.Comprehensive characterization and low-temperature denitrification tests revealed that calcite-induced structural modulation of coal-derived AC significantly enhances catalytic activity.Specifically,NO conversion increased from 88.3%of Mn-Ce/De-AC to 91.7%of Mn-Ce/De-AC-1CaCO_(3)(210℃).The improved SCR denitrification activity results from the enhancement of physicochemical properties including higher Mn^(4+)content and Ce^(4+)/Ce^(3+)ratio,an abundance of chemisorbed oxygen and acidic sites,which could strengthen the SCR reaction pathways(richer NH_(3)activated species and bidentate nitrate active species).Therefore,NO removal is enhanced.展开更多
In this study,the commonly used Cu or Mn-based low-temperature SCR catalysts were employed to investigate their different reaction behaviors in the presence of high-content water vapor.Experimental results reveal that...In this study,the commonly used Cu or Mn-based low-temperature SCR catalysts were employed to investigate their different reaction behaviors in the presence of high-content water vapor.Experimental results reveal that CuCeTi sample possesses superior water re sistance at low temperature compared with MnCeTi catalyst.Upon the introduction of water vapor,both catalysts exhibit a quick loss in deNOxefficiency,while that is more pronounced on MnCeTi sample.In addition,unlike CuCeTi sample,MnCeTi catalyst also shows a gradual deactivation tendency after initial quick activity loss.Characterization and simulation results indicate that H_(2)O is more easily adsorbed and dissociated on MnCeTi catalyst,showing stronger suppression on NH3adsorption,causing more serious initial deactivation.Furthermore,more abundant hydroxyl groups derived from dissociative adsorption of water on MnCeTi catalyst will lead to more NH4NO3deposition and the decrease in redox capacity.This is the main reason of gradual deactivation of MnCeTi catalyst at high-content water vapor.Such findings could pave a new way for development of highly efficient SCR catalysts with good water resistance for real application.展开更多
分子筛催化剂Ce-Cu-SSZ-13在与工业炉排烟温度一致的条件下具有卓越的选择性催化还原(Selective Catalytic Reduction,SCR)脱硝性能,将其涂覆于内含扩缩通道的蜂窝陶瓷表面制作高温复合SCR蓄热体,可实现烟气脱硝与余热回收设备一体化。...分子筛催化剂Ce-Cu-SSZ-13在与工业炉排烟温度一致的条件下具有卓越的选择性催化还原(Selective Catalytic Reduction,SCR)脱硝性能,将其涂覆于内含扩缩通道的蜂窝陶瓷表面制作高温复合SCR蓄热体,可实现烟气脱硝与余热回收设备一体化。为优化新型SCR蓄热体综合性能,以蓄热体长度(L)、扩张/收缩角(θ)和烟气流速(V)为设计变量,能量回收率(ERR)、脱硝效率(η)和烟气压力损失(ΔP)为目标函数,开展耦合蓄热式传热的SCR烟气脱硝Fluent数值模拟研究。根据模拟结果,采用响应面方法建立目标函数回归模型。在此基础上,采用多目标优化遗传算法NSGA-Ⅱ求得帕累托最优解集,使用基于熵权法(Entropy Weight Method,EWM)的熵权TOPSIS(Technique for Order Preference by Similarity to an Ideal Solution)法计算其与负理想解的相对接进度并以此确定最优解。方差分析验证回归模型的显著性,响应曲面分析则揭示了不同设计变量对目标函数的协同影响规律。结果表明,新型复合SCR蓄热体最佳设计变量为:L=717.57 mm,θ=12.19°和V=4.03 m/s,对应目标函数为ERR=68.13%,η=99.38%和ΔP=52.57 Pa。此时烟气出口温度约150℃,NO质量浓度为4.3 mg/m^(3)。另外,将烟气速度约束至5和6 m/s后发现最优解减小了扩张/收缩角,以防止蓄热体压力损失大幅增加。展开更多
基金Supported by the Science and Technology Cooperation and Exchange special project of Cooperation of Shanxi Province(202404041101014)the Fundamental Research Program of Shanxi Province(202403021212333)+3 种基金the Joint Funds of the National Natural Science Foundation of China(U24A20555)the Lvliang Key R&D of University-Local Cooperation(2023XDHZ10)the Initiation Fund for Doctoral Research of Taiyuan University of Science and Technology(20242026)the Outstanding Doctor Funding Award of Shanxi Province(20242080).
文摘To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content in coal)catalysts were prepared by the incipient wetness impregnation method,followed by acid washing to remove calcium-containing minerals.Comprehensive characterization and low-temperature denitrification tests revealed that calcite-induced structural modulation of coal-derived AC significantly enhances catalytic activity.Specifically,NO conversion increased from 88.3%of Mn-Ce/De-AC to 91.7%of Mn-Ce/De-AC-1CaCO_(3)(210℃).The improved SCR denitrification activity results from the enhancement of physicochemical properties including higher Mn^(4+)content and Ce^(4+)/Ce^(3+)ratio,an abundance of chemisorbed oxygen and acidic sites,which could strengthen the SCR reaction pathways(richer NH_(3)activated species and bidentate nitrate active species).Therefore,NO removal is enhanced.
基金Project supported by National Key R&D Program of China(2022YFC3701600)National Natural Science Foundation of China(22276162 and 22306072)+1 种基金China Postdoctoral Science Foundation(2023M731441)Young Talent Fund of Jiaxing Science and Technology Project(2023AY40030)。
文摘In this study,the commonly used Cu or Mn-based low-temperature SCR catalysts were employed to investigate their different reaction behaviors in the presence of high-content water vapor.Experimental results reveal that CuCeTi sample possesses superior water re sistance at low temperature compared with MnCeTi catalyst.Upon the introduction of water vapor,both catalysts exhibit a quick loss in deNOxefficiency,while that is more pronounced on MnCeTi sample.In addition,unlike CuCeTi sample,MnCeTi catalyst also shows a gradual deactivation tendency after initial quick activity loss.Characterization and simulation results indicate that H_(2)O is more easily adsorbed and dissociated on MnCeTi catalyst,showing stronger suppression on NH3adsorption,causing more serious initial deactivation.Furthermore,more abundant hydroxyl groups derived from dissociative adsorption of water on MnCeTi catalyst will lead to more NH4NO3deposition and the decrease in redox capacity.This is the main reason of gradual deactivation of MnCeTi catalyst at high-content water vapor.Such findings could pave a new way for development of highly efficient SCR catalysts with good water resistance for real application.
文摘分子筛催化剂Ce-Cu-SSZ-13在与工业炉排烟温度一致的条件下具有卓越的选择性催化还原(Selective Catalytic Reduction,SCR)脱硝性能,将其涂覆于内含扩缩通道的蜂窝陶瓷表面制作高温复合SCR蓄热体,可实现烟气脱硝与余热回收设备一体化。为优化新型SCR蓄热体综合性能,以蓄热体长度(L)、扩张/收缩角(θ)和烟气流速(V)为设计变量,能量回收率(ERR)、脱硝效率(η)和烟气压力损失(ΔP)为目标函数,开展耦合蓄热式传热的SCR烟气脱硝Fluent数值模拟研究。根据模拟结果,采用响应面方法建立目标函数回归模型。在此基础上,采用多目标优化遗传算法NSGA-Ⅱ求得帕累托最优解集,使用基于熵权法(Entropy Weight Method,EWM)的熵权TOPSIS(Technique for Order Preference by Similarity to an Ideal Solution)法计算其与负理想解的相对接进度并以此确定最优解。方差分析验证回归模型的显著性,响应曲面分析则揭示了不同设计变量对目标函数的协同影响规律。结果表明,新型复合SCR蓄热体最佳设计变量为:L=717.57 mm,θ=12.19°和V=4.03 m/s,对应目标函数为ERR=68.13%,η=99.38%和ΔP=52.57 Pa。此时烟气出口温度约150℃,NO质量浓度为4.3 mg/m^(3)。另外,将烟气速度约束至5和6 m/s后发现最优解减小了扩张/收缩角,以防止蓄热体压力损失大幅增加。
