Combining filtration and catalytic combustion in particulate traps for diesel exhaust treatment

Satisfying performance in Diesel soot abatement can be achieved by coupling ceramic-foam filters with carbon combustion catalysts. This paper focuses on the preparation, testing and the modelling of such reactors. A specific pilot plant, based on a conical fluidised bed of glass beads, used to dispe rse fixed parcels of Diesel soot into a given gas flow rate, was used to as sess the pressure drop and the filtration efficiency of the foam traps as a function of the soot particle size, the soot load in the filter, as well a s the superficial velocity. Then, several catalysts have been deposited int o different traps, whose abatement performance was evaluated in a specific pilot. plant where an acetylene burner was used to produce a soot-laden flu e gas. High abatement efficiency( > 80%), coupled with low-pressure drop ac ross the trap (100 mmH(2)O), has been obtained by using a catalyst based on Cs4V2O7. A mathematical model is presented and validated using the experim ental data obtained with catalytic and non-catalytic traps. The model agree ment with the experimental data was good in both cases and particularly pro mising for design purposes. (C) 2001 Elsevier Science Ltd. All rights reser ved.