It is possible that in a few years our problems with defective SCR systems and costly repairs will be over. Jülich research centre, in cooperation with the RWTH Aachen University and manufacturers from the automotive industry, is going to develop a catalyst that will reduce the emission of nitrogen oxides in fumes without using AdBlue.
Jülich research centre, in cooperation with the RWTH Aachen University and manufacturers like Ford, Deutz, Sasol, FEV, Umicore and Clariant, is working at the catalyst that will almost completely remove nitrogen oxides (NOx) from fumes. There is no need to use AdBlue because DeNOx acquires ammonia from fumes – comments the German automotive magazine, “Kfz-Betrieb”. The catalyst stores produced nitrogen oxide, and when it reaches maximum level, regeneration process begins.
Ammonia acquired from fumes
In addition to the hydrogen dioxide (H2), an engine also emits carbon monoxide (CO). In the catalyst, it is used to produce hydrogen through the so-called CO conversion. In this process, carbon monoxide reacts with water vapour from the emitted gases, creating carbon dioxide and hydrogen. After their merge with the nitrogen dioxides (NOx) stored in the catalyst, ammonia (NH3) is produced.
Thanks to the solution of the German scientists, in the future it will no longer be necessary to use the AdBlue factor, which is a solution of urea obtained synthetically from ammonia and carbon dioxide.
No more problems with defective SCR systems?
As the producers of the catalyst say, it should be as efficient as today’s selective catalytic reduction systems. Its cost will be comparable to the price of the SCR. The research centre claims that prototypes will be presented as soon as in three years.
If you believe the promises of German engineers, in a few years many entrepreneurs will breathe a sigh of relief and will happily say goodbye to systems using AdBlue fluid. That is because it malfunctions very often. If the faults are not removed in 50 hours, power and torque are reduced by up to 60%. (in vehicles manufactured after November 2017 or older ones with updated software).
Unfortunately, carriers cannot influence the most often cause of malfunction. Faults depend on temperature – too low or too high. AdBlue freezes at temperatures below -11°C. Frozen agent causes clogging of the injector and is one of the most often causes of AdBlue dosing system malfunction.
The system may also become useless because of too high temperatures – above 30°C.
Moreover, the costly nitrogen monoxide (NOx) sensor often malfunctions and in newer versions of the system (Euro5) is replaced with second exhaust system temperature sensor. Its price varies from EUR 650 to 1000.