Diesel exhaust purification

H. Christensen, J. Dinesen, H.H. Engell, and K.K. Hansen, Electrochemical Reactor for Exhaust Gas Purification, SAE paper 1999-01-0472, Diesel Exhaust Aftertreatment (SP-1414)225-229 (1999). 

The fact that Fischer-Tropsch fuels contain neither sulfur nor aromatics may become a strong selling point for the process. Less sulfur in the fuel has, of course, a direct effect on the sulfur oxides in the emissions, and the newly developed exhaust purification systems for lean burning engines that can be introduced means that all emissions, including GO2 and NOx, will diminish. Aromatics promote particulate formation in the combustion of diesel fuels and are therefore undesirable. We discuss this further in Ghapter 10. 

Structured catalysts are also essential in diesel exhaust gas purification. State-of-the-art solutions are marketed by PSA and by Johnson Matthey. The truck market is dominated by diesel engines. In that application, space requirement is a major issue, and intensification is badly needed. Space velocities exceeding 100,000 h 1 arc demanded. Reactive structured filters are the way to go. 

The selective catalytic reduction (SCR) of nitrogen monoxide by hydrocarbons in excess oxygen currently appears to be the best method for the removal of NO from exhaust streams. This is also a key issue in catalytic purification of diesel exhaust gases, but even more complex due to the presence of SOx. 

H. Suzuki, N. Koike, H. Ishii, M. Odaka "Exhaust Purification of Diesel Engines by Homogenous Qiarge with Compression Ignition Part 2 Analysis of Combustion Phenomena and NOx Formation by Numerical Simulation with Experiment." SAE Paper 970315. 

Diesel and gasoline exhaust gas purification has drawn increasing attention. Catalyst materials containing different noble metals, such as Pd, Pt, and Rh,... 

Catalytic Purification of Diesel-Engine Exhaust An Overview... 

The goal of this paper is to represent a fifth direction of an intense research effort focused on electrochemical cells for the reduction of NOx gases due to the need to design an effective method for the purification of the exhaust gases from lean bum and diesel engines. 

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