Selective catalytic reduction (SCR) employs AdBlue, a reducing agent over a catalytic surface to reduce the oxides of nitrogen (NO_x) emission in diesel engines. SCR's inherent problem is its poor cold start performance at exhaust temperatures below 150°C. In the current work, the researcher has discussed the investigation of two techniques to enhance low-temperature NO_x conversion and combined them to achieve the best results. First, AdBlue injection was replaced by gaseous ammonia injection. The gaseous ammonia was generated by heating solid ammonia precursor materials such as solid urea and ammonium carbonate. Second, to improve the catalytic performance, MnCeZrO_x catalysts were introduced instead of conventional CuZ catalysts. MnCeZrO_x were prepared in the laboratory using its component materials. The prepared catalyst was tested through SEM and EDAX analysis. The newly developed SCR system was tested and compared with a conventional Adblue-CuZ SCR. The results revealed with diesel fuel at exhaust temperatures below 150°C the ammonia-MnCeZrO_x SCR system gave a 90% increase in NO_x reduction compared to the conventional system. With biodiesel blend jatropha B20 the conversion was greater than 80% from 100 to 150°C. A maximum NO_x conversion of 95% was obtained for diesel and 93% for jatropha Biodiesel blend B20.

中文翻译：

---

直接喷氨选择性催化还原和锰铈氧化锆催化剂促进生物柴油尾气低温氮氧化物减排的实验研究

选择性催化还原 (SCR) 使用 AdBlue，一种在催化表面上的还原剂，以减少柴油发动机中氮氧化物 (NO _x ) 的排放。SCR 的固有问题是其在排气温度低于 150°C 时冷启动性能不佳。在目前的工作中，研究人员讨论了两种提高低温NO _x转化的技术的研究，并将它们结合起来以达到最佳效果。首先，AdBlue 注射液被气态氨注射液取代。气态氨是通过加热固体氨前体材料如固体尿素和碳酸铵而产生的。其次，为了提高催化性能，引入MnCeZrO _x催化剂代替传统的CuZ催化剂。MnCeZrO _X使用其成分材料在实验室中制备。通过SEM和EDAX分析测试制备的催化剂。对新开发的 SCR 系统进行了测试，并与传统的 Adblue-CuZ SCR 进行了比较。结果表明，在排气温度低于 150°C 的柴油燃料中，氨-MnCeZrO _x SCR 系统与传统系统相比，NO _x减少量增加了 90% 。使用生物柴油混合麻风树 B20，从 100 到 150°C 的转化率大于 80%。柴油的最大 NO _x转化率为 95%，麻风树生物柴油混合物 B20的最大 NOx转化率为 93%。