Post-treatment of polluting emmissions from internal combustion thermal engines - Positive-ignition engines

The main anthropogenic sources of atmospheric pollutants are: transport, energy production, industry, housing, agriculture...

In the case of transport, and more specifically automobiles, mechanical energy is produced by internal combustion engines (gasoline and diesel) for which the combustion processes, although constantly optimized, remain incomplete.

In addition to carbon dioxide, water, nitrogen, oxygen and heat, regulated pollutants include hydrocarbons (unburned or partially transformed fuel), carbon monoxide (CO), nitrogen oxides (NOx = NO + NO ₂ ), particulate matter (PM = Particulate Matter) and unregulated pollutants such as nitrogen dioxide NO ₂ , nitrous oxide (N ₂ O), polycyclic aromatic hydrocarbons (PAHs), sulfur dioxide (SO ₂ ), aldehydes (regulated in the USA), ketones...

Recognition of the harmful effects of gaseous and particulate emissions on health has led to the introduction of regulations (see [BM 2 506] and [BM 2 507] "Pollutant emissions from internal combustion engines" by Anne Jaecker-Voirol) limiting these emissions to levels that have imposed the use of after-treatment systems for automotive emissions.

The history of post-processing is punctuated by key events that often preceded global regulations:

– United States: 1975, oxidation catalysis for petrol vehicles;

1981, 3-way catalytic converter for petrol vehicles ;

– Japan: 1980, 3-way catalysis for petrol vehicles;

1985, DeNOx catalysis for lean-burn petrol vehicles;

– in Europe: 1992, 3-way catalytic converter for petrol vehicles;

1995, oxidation catalysis for diesel vehicles;

2000, particulate filter with fuel additive for diesel vehicles ;

2003, catalyzed filter for diesel vehicles.

These devices for...