How to get rid of crystallisation in SCR systems
Additive and clean engine specialist, Forté, talks Adblue crystals – what crystallisation is, the causes, the signs to look out for and how to get rid of them.
What is crystallisation in selective catalytic reduction (SCR)? Simply put, crystallisation in SCR refers to the formation of crystal deposits on the surfaces of the catalyst within the SCR system.
So, what causes it, you might ask? AdBlue crystals are primarily caused by the reaction of ammonia-based reductants, such as urea or ammonia, under certain conditions. While crystallisation is more likely to occur in colder temperatures, it can also affect vehicles that mainly operate in cities and towns at low speeds.
Does crystallisation impact the AdBlue tank? In short, yes. When crystals form in the AdBlue tank, lines and pump it can cause damage and prevent the level sensor in the tank performing properly. As a result, when the vehicle is filled with AdBlue, it will not register the fill and report that the tank is empty, stopping the system and vehicle working.
Understandably this prompts many technicians to wanting to understand how best remove AdBlue crystals to ensure vehicles run smoothly and replacement tanks do not need to be ordered.
What are the tell-tale signs of crystallisation build-up in an SCR system? There are a number which you might encounter individually or in conjunction with each other. They include:
- reduced NOx reduction efficiency
- increased NOx emissions
- unusual odours like ammonia
- altered engine performance
- warning lights or fault codes
- visible smoke or fumes
- system error messages
Regular monitoring and maintenance are crucial for early detection and resolution of these issues. Here at Forté, we believe it’s all about prevention…
Is crystallisation preventable? Yes, crystallisation in SCR systems is preventable through proactive maintenance measures. Cleaning the oil and fuel system at regular intervals will maintain oil system cleanliness and efficiency, fuel injector spray patterns and operation. This in turn will maintain exhaust gas temperatures to aid the operation of the SCR catalyst and reduce system faults.
When trying to better understand how to remove AdBlue crystals, adding proprietary treatments, such as our exhaust crystal preventer in the Adblue system at every refill, will prevent crystallisation build-up and reduce component failure.
Are there any other treatments to consider to help remove AdBlue crystals? We recommend using our advanced formula diesel treatment to clean the fuel system at regular intervals and maintain fuel system cleanliness, efficiency and restore fuel injector spray patterns and operation. This will help to maintain exhaust gas temperatures to aid the operation of the SCR catalyst and reduce system faults.
In addition, using the Forté exhaust crystal preventer in the AdBlue system will prevent crystallisation and reduce component failure. We recommend using these products alongside each other for the best performance, and in between services, when refilling the AdBlue tank, add Forté exhaust crystal preventer directly to the AdBlue tank. When it comes to understanding how to remove AdBlue crystals, our products and expert advice can help prevent, reduce and fix the effects crystallisation can have on vehicles.
