Search Results

Urea-SCR system consisted of combined deNOx catalysts with wide range of temperature window, injector, sensor and injection controller. Synthetic gas activity test and NOx conversion efficiency test on the engine bench were carried out to evaluate and improve the performance of this system. To better suit the application of the urea-SCR system without engine modification, temperature of catalyst and engine RPM were used as input data to control amounts of urea aqueous solution that reacts with NOx. We concentrated on designing types of deNOx catalysts and controlling amounts of urea solution under different driving conditions to achieve higher NOx reduction and wider temperature window. Designed urea-SCR system showed substantial NOx reduction performance and relatively wide temperature window under different driving conditions.

To meet EURO 4 diesel passenger car emission regulations, various experiments of a catalyzed particulate filter (CPF) system have been performed with 2.0L common-rail diesel engine. The main components of a CPF system are a filter and a catalyst, thus we performed the optimization of these two components accordingly. First, we constructed a system with a high porosity silicon carbide (SiC) filter coated with a catalyst washcoat and precious metal loading optimized for performance, cost, etc. We primarily investigated the effects of the catalyst on the DOC and CPF on the diesel emissions. We performed various catalytic activity experiments in order to verify the effects of filter shape, catalyst washcoat loading amount, precious metal loading amount, aging effects through regeneration, etc. Finally we evaluated the catalytic activities through the European vehicle emission driving cycle (NEDC) mode.