Avgasbehandling

Avgasbehandling, or exhaust gas treatment, refers to systems and processes installed on internal combustion engines to reduce pollutants in the exhaust stream before it is released to the atmosphere. The aim is to meet environmental regulations and minimize health and environmental impacts.

Main aftertreatment technologies include oxidation catalysts, which convert carbon monoxide and hydrocarbons into carbon dioxide and water; three-way catalysts used on many gasoline engines; diesel oxidation catalysts for light and heavy-duty diesels; diesel particulate filters that trap soot and require periodic regeneration; and selective catalytic reduction, which uses ammonia (from urea) to convert NOx into nitrogen and water. Lean NOx traps are used in some diesel applications. Exhaust gas recirculation can also reduce NOx by lowering combustion temperatures and oxygen concentration.

System integration and operation rely on carefully coordinated hardware and control strategies. Aftertreatment modules are placed close to the engine, and effective operation depends on maintaining sufficient exhaust temperatures and proper thermal management. Sensors and an electronic control unit regulate dosing for SCR systems, monitor catalyst health, and manage regenerator cycles for particulate filters. Maintenance considerations include catalyst aging and sulfur poisoning, ash buildup in filters, and the need to refill urea solutions in SCR systems.

Applications span passenger cars, trucks, buses, off-road machinery, and marine and stationary engines. Regulatory frameworks such as Euro 6 and various EPA standards drive the adoption of avgasbehandling to reduce emissions of NOx, CO, hydrocarbons, and particulate matter. Ongoing developments focus on advanced catalysts, improved energy efficiency, and compatibility with alternative fuels and powertrains.