Process and device for removing soot particles from diesel engine exhaust gas

A process for producing substantially soot-free exhaust gas from a diesel engine by continuous combustion of the soot particles collected by a particle filter with the aid of nitrogen dioxide which is produced by catalytic oxidation of nitrogen monoxide contained in the exhaust gas, the improvement comprising:

• a. filtering the exhaust gas containing soot particles using a deep-bed particle filter to provide an initially filtered exhaust gas, wherein the deep-bed particle filter has a filtration efficiency for soot particles and is coated with a catalytic coating for oxidizing nitrogen monoxide to nitrogen dioxide;
• b. continuously combusting the soot particles collected within the deep-bed particle filter with the aid of nitrogen dioxide obtained by oxidizing the nitrogen monoxide contained in the exhaust gas at the catalytic coating of the filter and reducing the nitrogen dioxide back to nitrogen monoxide while combusting the soot particles, whereby the process of oxidizing and reducing of nitrogen monoxide is continuously repeated while the exhaust gas is passing the filter;
• and
• c. further filtering the initially filtered exhaust gas from the deep-bed particle filter through a second particle filter, wherein the second particle filter serves as a soot barrier, has a filtration efficiency of at least 10% to produce a substantially soot-free exhaust gas.