AdBlue, the diesel engine's ally in polluting less

Diesel engines are being singled out as one of the main causes of the pollution problems in cities, and authorities want the problem they create to be smaller and smaller. The Euro 6 standard has already improved this problem considerably and since its introduction, nitrogen oxide levels are being controlled more and more. In fact, manufacturers that falsified their data to get around this standard have run into quite a few problems, as we already know happened with the Dieselgate.

This type of engine, those that use diesel as fuel, produces a greater number of polluting gases that directly affect our bodies, because the fuel is less refined and combustion produces all these polluting gases. This is addressed after combustion, with particulate filters and other methods that eliminate the risk quite effectively, reducing the incidence of these gases. One of those processes is carried out thanks to a product commercially called AdBlue.

AdBlue, a product that converts NOx into nitrogen and water vapour

This product is necessary so that the polluting gases produced by diesel engines are converted into other harmless gases. Its function is to mix with the waste leaving the engine and trigger a chemical change that neutralises the NOx gases and prevents greater pollution. AdBlue is a registered trademark, and it is actually made up of deionised water with a 32.5% urea solution.

This product is injected into the car’s exhaust under pressure, so that it mixes with the gases resulting from combustion and an instant change occurs that neutralises the NOx that could otherwise reach the atmosphere. Practically all diesel cars built after the Euro 6 standard have an AdBlue tank, so diesel engines are considerably cleaner than their counterparts from ten years ago.

How AdBlue works

AdBlue is injected into the catalytic converter, which the gases coming from the engine also pass through. The injector sprays the atomised urea, so very little is used, and with 20-litre tanks it provides a range of 20,000 kilometres, which offers considerable mobility. An ECU calculates the amount of AdBlue required and sends it to the catalytic converter, so that the quantity of this product is proportional to the gases emitted and the chemical reaction effectively neutralises the polluting gases.

Filling the AdBlue tank

The AdBlue is stored in a tank and its level is monitored by a warning light on the instrument panel. AdBlue is sold in canisters of various sizes, which are used to fill the tank and allow the car to run properly. If the tank runs empty, the car will not start, and you would need to refill it and wait for the sensor to detect the liquid level.

At many petrol stations there are AdBlue pumps, but they are mainly intended for heavy vehicles, since dispensing under pressure can damage the tank’s level sensor system and cause problems.

Several precautions must be taken with AdBlue, as it is a fairly corrosive liquid and can cause damage to the skin and to the car’s bodywork paint if it spills onto it. It is advisable to fill the AdBlue tank wearing gloves and protective goggles, to avoid accidents. In addition, bear in mind that this product loses its properties after one year, so check the expiry date printed on each container.