|« What is CPS?||What is CPS? »|
SCR – the urea-based solution.
SCR stands for selective catalytic reduction, a process in which nitrogen oxides are converted into water and pure nitrogen. This is achieved by using a synthetic aqueous solution of urea (AdBlue®1), which is carried in an additional tank. SCR has the advantage that the combustion in the engine can take place under optimum conditions, thereby increasing efficiency.
However, it is necessary to equip the vehicle with an additional tank system as well as a metering and injection system for AdBlue®. This hardware, the provision of the urea solution and the task of filling the additional tank generate additional costs.
EGR and DPF – the filter-based solution.
In engines equipped with EGR (exhaust gas recirculation) plus DPF (diesel particulate filter), a proportion of the engine exhaust gas is mixed with the intake air. This reduces the combustion temperature in the engine and so largely prevents the formation of nitrogen oxides.
But: compliance with the particulate limits is possible only with a particulate filter (DPF). The advantage of EGR – that there is no need for an additional tank or an additional service fluid – has to be considered in the light of the fact that the engine has to force air through the particulate filter all the time and doing this consumes additional power.
the CLAAS dialogue platform.
New emission control technologies, alternative drive systems, biofuels – farmers and manufacturers alike have to prepare for a raft of further changes. At CLAAS we regard this as a dynamic process and are therefore committed to developing our dialogue with our customers. It is with this in mind that we have set up the kraftintelligenz.com site and warmly invite you to join in and tell us what you think.
What's it to be? SCR or EGR?
It is impossible for anyone to give a definitive recommendation for one solution or another at the moment. What is certain, however, is that reducing pollutant emissions has a cost. Complying with exhaust emission standards while maintaining a high engine output calls for a considerable degree of further product development. And it is a fact that both SCR and EGR are suitable solutions for reducing exhaust emissions.