Heavy Duty Diesel

Along with a step-by-step thightening of established and the introduction of new HDD On- and Nonroad legislation, the most stringent requirements in terms of green-house gas (GHG) regulations, fuel efficiency and low NOx standards are currently emerging in the US.

California (CARB) is considering tightening HDD NOx regulations by up to 90%, and the US Environmental Protection Agency (EPA) is finalizing the next round of GHG tightening. The NOx tightening would require significant cold-start and low-temperature DeNOx technology. Leading technology approaches include advanced DOC and cDPF technologies, SCR-coated filters, passive NOx adsorbers and selective ammonia oxidation catalysts. The combination of such technologies to high-performing and sophisticated system designs along with engine measures and auxiliary heating devices is required to cope with the ambitious goal to reach the CARB targeted NOx tailpipe emission level of 0,02 g/bhp-hr. Step-by-step introduction is foreseen for 2021, 2024 and 2027.

Europe most probably will adopt such US regulations for an introduction of EURO VII, which is not fixed yet in terms of limits and timing. More stringent OBD requirements and a better reflection of real driving emissions are subject to the EURO VI-d implementation in 2019.

Umicore offers a full technology portfolio and development work is been done closely with our customers. Therefore, Umicore provides a full range of test facilities for simulation&modelling, synthetic gas bench evaluations and full size HDD engine bench testing.

The development focus to meet the performance challenges is two-folded:

The first approach will improve the thermal conditions specifically for the components of the SCR sub-system with the urea injection device. This includes varying the positions of functional units in the exhaust line and optimizing the geometrical arrangement, reducing heat capacity, improving insulation and applying external energy for optimal heat-up and urea decomposition.

The second approach is to improve individual functions to better cope with lower temperatures, which addresses requirements especially to the SCR catalyst itself and the urea injection unit.

Other significant HDD regulations are being introduced in the developing countries. China and India follow European standards. China introduces CN V in 2016/17 and from 2020 on CN VI will be mandatory. India skips Bharat V and goes directly from Bharat IV to Bharat VI in 2020. Such legislative approaches require the widespread availability of low sulfur fuel (10 ppm S).

Other regulatory developments involve the next round of tightening for the European Nonroad mobile machinery (Stage V) for 2019 and the implementation of Euro VI levels in Brazil beyond 2020.

Such global requirements and different engine maker philosophies require Umicore to having a full portfolio on SCR catalyst technologies: Fe-, Cu- and V-SCR.




Traditional systems used today

Onroad: System design for US2010, EuroVI and JP16


  • Well proven and robust system
  • Improved passive regeneration efficiency
  • Active regeneration applicable w/o major restrictions


  • High packaging volume

Nonroad: System designs for Nonroad Stage IV

Stage V requires system volume reduction

Integration of functionalities is being implemented on the filter to reduce volume.

Pros and Cons for different System Concepts



  • Well proven for Tier IVf
  • Improved passive regeneration efficiency
  • Active Regeneration applicable w/o major restrictions


  • High packaging volume



  • Volume saving potential 15-20%
  • Improved cold start De-NOx activity
  • Potentially 1 brick less to can


  • Significantly reduced passive regeneration efficiency
  • Some technological risks: still not field proven



  • Volume saving potential 10-15%
  • Saves one brick


  • Very limited active regen capability
  • Slightly compromised passive regeneration efficiency

Global Trends & Challenges


  • Focus on fuel consumption
  • Implication of in use & OBD regulations?
  • Regulation of secondary emissions?
  • Nonroad: development of DPF use / Stage V

North America

  • Growing importance of fuel consumption
  • Implication of ln use & OBD regulations?
  • N2O to be considered
  • CARB proposal for lower NOx


  • Growing importance of fuel consumption
  • Coming JP16
  • Focus on low temperature applications

BRIC & similar countries

  • V-SCR dominant solution
  • Development of fuel quality & urea supply?
  • When to expect "Tier iVi"?