Emission Control

Commercial Vehicle Workshop magazine features the three types of fluids which are important to consider when servicing emission control equipment.

Emissions from diesel engines, notably particulates and NOx, are extremely damaging to human health, especially at the concentrations experienced in large cities. The recognition of this problem has led to a series of ever demanding emissions standards – the Euro levels – which have reduced the permissible levels of harmful emissions to a fraction of the Euro 1 (1992) limits: 5% for NOx, 2.8% for particulate matter. The increasing demands of legislation have led to a corresponding acceleration of changes in vehicle hardware.

Such is the scale of these changes, that it is not possible to design a diesel engine which can meet the latest Euro levels on its own. Instead, it is a combination of two components, the engine and the exhaust systems, which are certified together. The exhaust itself will contain either one of, or a combination of, two main technologies:

Selective Catalytic Reduction (SCR) – a combination of two catalysts and urea solution (AdBlue) injection, used to reduce NOx emissions.

Diesel Particulate Filters (DPF) – a ceramic porous soot filter sometimes combined with an oxidation pre-catalyst, DPFs are used to remove soot particles.

Workshops servicing and repairing these increasingly complex systems should bear in mind the importance of the three types of fluids running alongside and within them – the Fuels, Lubricants and Additives.

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