Selective catalytic reduction with NH3(NH3-SCR)is an important means of NO_(x) abatement from stationary and mobile sources,and the key element is efficient and stable NH3-SCR catalysts.In this study,we propose a meth...Selective catalytic reduction with NH3(NH3-SCR)is an important means of NO_(x) abatement from stationary and mobile sources,and the key element is efficient and stable NH3-SCR catalysts.In this study,we propose a method to construct superior Fe-Beta catalysts based on Al-rich zeolites.This strategy successfully promotes the formation of NH3-SCR-active isolated Fe^(3+)species,thus effectively improving the low-temperature activity of the Fe-Beta catalysts.Thanks to the abundant Brønsted acid sites of the Al-rich zeolite,the Fe_(2)O_(3) particles are redispersed and anchored as isolated Fe^(3+)during hydrothermal aging.This dynamic evolution of Fe species makes up for the adverse effect of dealumination of the Al-rich zeolite framework and achieves high stability for the Al-rich Fe-Beta catalyst.This study may promote the understanding of highly efficient and stable catalyst design using Al-rich zeolites.展开更多
本研究基于自行搭建的5 k W旋流预混火焰实验台,开展了轴向空气分级方式下CH_(4)/NH_(3)旋流预混火焰的实验测试,重点考察了分级风比例、分级风高度及分级风喷口数目对CH_(4)/NH_(3)旋流预混火焰燃烧及排放特性的影响。结果表明:随着NH_...本研究基于自行搭建的5 k W旋流预混火焰实验台,开展了轴向空气分级方式下CH_(4)/NH_(3)旋流预混火焰的实验测试,重点考察了分级风比例、分级风高度及分级风喷口数目对CH_(4)/NH_(3)旋流预混火焰燃烧及排放特性的影响。结果表明:随着NH_(3)占比的增大,火焰高度变长,燃烧室出口的NO排放量呈先增大后减小的趋势且在NH_(3)占比为50%达到峰值;在50%掺氨工况下采用轴向空气分级使一级燃烧室处于富燃状态可以有效降低NO的排放,其中分级风的最佳比例范围是30%~50%(当量比1.21~1.70),且随着分级风高度的增大呈下降趋势;此外,在最佳分级风比例和高度条件下(分级风高度80 mm、占比30%),增加分级风的喷口数目可减轻分级风碰撞对上游主燃区富燃状态的影响,使NO排放进一步降低。展开更多
基金supported by the National Key R&D Program of China(No.2023YFC3707200)the National Natural Science Foundation of China(Nos.22306191 and 52270112).
文摘Selective catalytic reduction with NH3(NH3-SCR)is an important means of NO_(x) abatement from stationary and mobile sources,and the key element is efficient and stable NH3-SCR catalysts.In this study,we propose a method to construct superior Fe-Beta catalysts based on Al-rich zeolites.This strategy successfully promotes the formation of NH3-SCR-active isolated Fe^(3+)species,thus effectively improving the low-temperature activity of the Fe-Beta catalysts.Thanks to the abundant Brønsted acid sites of the Al-rich zeolite,the Fe_(2)O_(3) particles are redispersed and anchored as isolated Fe^(3+)during hydrothermal aging.This dynamic evolution of Fe species makes up for the adverse effect of dealumination of the Al-rich zeolite framework and achieves high stability for the Al-rich Fe-Beta catalyst.This study may promote the understanding of highly efficient and stable catalyst design using Al-rich zeolites.
文摘本研究基于自行搭建的5 k W旋流预混火焰实验台,开展了轴向空气分级方式下CH_(4)/NH_(3)旋流预混火焰的实验测试,重点考察了分级风比例、分级风高度及分级风喷口数目对CH_(4)/NH_(3)旋流预混火焰燃烧及排放特性的影响。结果表明:随着NH_(3)占比的增大,火焰高度变长,燃烧室出口的NO排放量呈先增大后减小的趋势且在NH_(3)占比为50%达到峰值;在50%掺氨工况下采用轴向空气分级使一级燃烧室处于富燃状态可以有效降低NO的排放,其中分级风的最佳比例范围是30%~50%(当量比1.21~1.70),且随着分级风高度的增大呈下降趋势;此外,在最佳分级风比例和高度条件下(分级风高度80 mm、占比30%),增加分级风的喷口数目可减轻分级风碰撞对上游主燃区富燃状态的影响,使NO排放进一步降低。
