Experiments and Analysis of Diesel Particulate Filter Loading and Regeneration 2000-01-3087
Experimental measurements of diesel particulate filter (DPF) soot loading and regeneration have been performed with an engine test cell and a laboratory flow reactor. In the test cell experiments, platinum-catalyzed and non-catalyzed filters were loaded with particulate matter emitted from a 7.3-l engine. Regeneration was initiated in two different ways: increasing engine load or with fuel injection upstream of the filter. The flow reactor used loaded filters from the test cell, which were regenerated at three temperatures and two space velocities.
The catalyzed filter showed faster regeneration than the non-catalyzed filter in the engine test cell. Fuel injection was shown to be an effective regeneration initiator. Flow reactor results confirmed that the soot oxidation rate is strongly temperature dependent and that at temperatures between 400 and 700 °C can be characterized by an Arrhenius-type expression. The catalytic coating led to soot oxidation rates that were between 6 and 16 times higher than that of the uncoated DPF, and halved the activation energy. Approximate activation energies of 38 kJ/mol and 85 kJ/mol for the catalyzed and uncatalyzed DPFs, respectively, were obtained at space velocities of 35,000 and 70,000 hr-1, 18% O2, and NOx levels below 30 ppm.