Application of storage catalytic converters of nitrogen oxides for reducing exhaust toxicity of tractor diesel engines

Reduction of harmful effects of agricultural machinery on the ecosphere is an important task; its solution requires extensive use of emission reducing devices. Compliance with up-to-date legal requirements causes the cost increase of systems of diesel exhaust gases aftertreatment. This applies especially the systems that require an additional reagent feeding into exhaust system. The cost factor determines the study aim that is the creation of prototype of alternative aftertreatment system for selected engine type with the possibility of rapid adaptation to other types of the same power class. The article considers the operating principles of a storage-type system of catalytic reduction of nitrogen oxides, the design features of the system for tractor engine. An important advantage of this system is the fact that there is no need for additional reagent. The experimental studies of converter prototype as part of series-production engine were conducted on the engine test bench. In addition, the tests of samples of catalyst bricks with different types of catalytic coating were carried out. As a result of testing and selection of optimal catalytic coating, the new fuel supply system with increased performance is obtained and the converter design recommended for agricultural machinery is modified. The storage catalytic converter system allows to reduce the nitrogen oxides emissions by 40-50 %. With such efficiency of the system, its cost is noticeably lower than the cost of the system of selective catalytic reduction. The proposed design allows to adapt the storage system to engines of any power class without change in systems and control algorithms. The optimal field of application of storage systems is determined.

nitrogen oxides, exhaust gases aftertreatment, storage catalytic converter, lean nitrogen oxides trap