首页|铁基分子筛SCR反应组分沿催化剂轴向分布的数值模拟

铁基分子筛SCR反应组分沿催化剂轴向分布的数值模拟

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建立铁基分子筛催化剂NH3-SCR催化反应动力学模型，用来预测催化剂的NOx还原性能和研究SCR反应组分的轴向分布，该模型包括NH3 吸附与脱附、NH3 氧化、NO氧化、NOx还原及N2O生成反应。结果表明:模型能较好地预测 SCR 反应中各组分浓度在催化剂轴向空间的变化规律;Fe 基分子筛催化剂对物质的量n(NO2)/n(NOx)较为敏感，最佳n(NO2)/n(NOx)为 0。5;受NH3抑制效应影响，当温度低于 300℃时SCR反应活性较低，但是当温度高于 400℃时SCR反应活性较好。此外，发现Fe基分子筛催化剂SCR反应主要集中在催化剂的入口段和中间段，300℃、空速为 60000 h-1时在催化剂的前半段内可实现高达 90%的NOx转化率，催化剂出口段的利用率较低。最后，对模型的瞬态性能进行了考察，发现随着温度升高 Fe 基分子筛催化剂的瞬态响应可以得到改善。
Numerical Simulation of Axial Species Distribution of SCR Reaction over Fe-Zeolite Catalyst
A kinetic model of NH3-SCR catalytic reaction over Fe-zeolite catalyst was established to predict the NOx reduction performance of the catalyst and to investigate the axial species distribution during SCR reaction.The model is composed of NH3 adsorption and desorption,NH3 oxidation,NO oxidation,NOx reduction and N2O formation reactions.The results show that the model can predict the variation of species concentration in axial space.It was found that the Fe-zeolite catalyst is sensitive to molar ratio of n(NO2)/n(NOx),and the optimal n(NO2)/n(NOx)is 0.5.Because of the NH3 inhibition effect,the SCR activity is low at the temperature lower than 300℃,while high at the temperature above 400℃.In addition,the SCR reaction of Fe-zeolite occurs mainly in the inlet and middle segments of the catalyst.At the temperature of 300℃and the space velocity of 60000 h-1,up to 90% NOx conversion could be achieved in the front half of the catalyst.The utilization rate of the catalyst is low at the outlet segment of the catalyst.Furthermore,the transient performance of the model was investigated,and it is found that the transient response of Fe-zeolite catalyst was improved with the temperature increasing.

diesel enginezeolite catalystselective catalytic reductionaxial distributionnumerical simulation

吕志华、苏庆运、佟德辉、张学敏、李宁、李凌志

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潍柴动力股份有限公司 内燃机与动力系统全国重点实验室,山东 潍坊 261061

大连理工大学内燃机研究所,辽宁 大连 116024

潍柴动力空气净化科技有限公司,山东 潍坊 261061

柴油机 分子筛催化剂 选择性催化还原 轴向分布 数值模拟

国家自然科学基金资助项目国家自然科学基金资助项目中国博士后科学基金资助项目天津大学内燃机燃烧学国家重点实验室开放基金资助项目中央高校基本科研业务费专项资金资助项目

51876028514760212016M590651K2016-10DUT15QY25

2024

10.16236/j.cnki.nrjxb.202403029

内燃机学报
中国内燃机学会

内燃机学报

CSTPCD北大核心
影响因子：0.76
ISSN：1000-0909
年,卷(期)：2024.42(3)
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