Comparative Analysis of Different Heavy Duty Diesel Oxidation Catalysts Configurations

Diesel Oxidation Catalyst in conjunction with large frontal area substrates is a key element in HDV Diesel emission control systems. This paper describes and reviews tests on a set of various Diesel Oxidation Catalyst configurations (for example cell densities), all with the same catalyst coating. The Diesel Oxidation Catalyst specimens were subjected to the European Stationary Cycle (ESC), the European Transient Cycle (ETC), and the US heavy duty Federal Test Procedure (US FTP). The focus was to study relative emissions, pressure drop, and light-off performance. All tests were conducted using the same Detroit Diesel Series 60 engine operating on ultra low sulfur diesel fuel. In addition to this, the exhaust was regulated so that the backpressure on the engine, upstream of the catalyst was also the same for all catalysts. The engine, the exhaust system, and the Diesel Oxidation Catalyst were properly instrumented to monitor incoming exhaust composition and final emissions, temperatures, mass flows, and pressure drop. Prior to the catalyst screening each catalyst was degreened by conducting two ESC and two US heavy-duty transient cycles in an alternate order back-to-back starting with the ESC to guarantee a proper seal between substrate, housing, and mat material. The test procedures will be explained in detail and the analysis of the data and conclusions for performance differences discussed.