柴油机钒基与沸石基SCR催化剂对比试验研究

发布时间：2018-04-06 00:18

本文选题：内燃机　切入点：柴油机　出处：《内燃机工程》2016年05期

【摘要】：在柴油机台架上比较了钒基、Cu沸石、Fe沸石选择性催化还原(selective catalytic reduction,SCR)催化剂的稳态转化效率、动态反应特性、副反应产物等性能,试验中SCR喷射系统、催化剂规格和封装形式保持一致。试验结果表明:Cu沸石SCR低温转化效率高于钒基SCR和Fe沸石SCR;前置柴油机氧化催化器(diesel oxidation catalyst,DOC)能够显著提高钒基SCR和Fe沸石SCR催化剂低温转化效率;NO2/NOx摩尔比超过50%时,钒基SCR催化剂的转化效率下降,沸石SCR催化剂的转化效率不受影响;钒基SCR催化剂比沸石SCR催化剂的饱和氨存储量低,动态响应速率也较快,在低温段Cu沸石比Fe沸石SCR催化剂吸附氨气的能力更强;SCR反应中,Cu沸石SCR催化剂比钒基和Fe沸石SCR催化剂更容易生成N2O,当有前置DOC时Cu沸石SCR催化剂的N2O生成量进一步提高。
[Abstract]:The steady-state conversion efficiency, dynamic reaction characteristics and side reaction products of vanadium based Cu zeolite and Fe zeolite selective catalytic reduction of selective catalytic reduction catalyst were compared on a diesel engine bench. The SCR injection system was used in the experiment.The catalyst specification is consistent with the package form.The results show that the low temperature conversion efficiency of SCR is higher than that of vanadium based SCR and Fe zeolite SCR, and the oxidation catalyst oxidation catalyst can significantly improve the conversion efficiency of vanadium based SCR and Fe zeolite SCR catalysts when the molar ratio of no _ 2 / no _ x is more than 50%.The conversion efficiency of vanadium based SCR catalyst was decreased, but the conversion efficiency of zeolite SCR catalyst was not affected, vanadium based SCR catalyst had lower storage capacity of saturated ammonia than zeolite SCR catalyst, and the dynamic response rate of vanadium based SCR catalyst was also faster than that of zeolite SCR catalyst.In the low temperature stage Cu zeolite is more capable of adsorbing ammonia than Fe zeolite SCR catalyst. The Cu zeolite SCR catalyst is easier to produce N 2O than vanadium base and Fe zeolite SCR catalyst, and the N 2O production of Cu zeolite SCR catalyst is further increased when there is DOC precursor.
【作者单位】：浙江正信车辆检测有限公司;清华大学汽车安全与节能国家重点实验室;
【基金】：国家“八六三”高技术研究发展计划项目(2013AA065304)
【分类号】：TK427

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