Heavy Duty Vehicle Aftertreatment Technologies for the Future: what may be required at BSVII?

The Euro-VII proposal for new emission standards has been initiated by the European Commission for on-road vehicles which will apply to heavy-duty vehicles. This transition from Euro VI to Euro VII is going to be effective from 1st July 2027 for heavy-duty vehicles. If BS-VII legislation follows the example of Euro-VII, there will be an introduction of limits on hot and cold emissions to reduce emissions in the cold cycle. Such a change will drive improvement in emissions performance in the cold cycle. A further change in BSVII could be an introduction of a limit on nitrous oxide (N2O), following the Euro VII example, in addition to the harmful emissions like carbon monoxide (CO), nitrogen oxides (NOx), hydrocarbons (HCs), particles (PM & PN) and ammonia (NH3) has been already regulated under BS-VI legislation. Should BS-VII legislation follow the example of Euro-VII, more advanced system performance from the engine and catalyst is needed. This paper will describe the after-treatment technology which could be used to meet a future BSVII standard, considering close-coupled SCR (cc-SCR) to help to start NOx conversion earlier. V-SCR may be considered in the rear position because V-SCR shows a fast response with very low N2O formation. New-V-SCR technology shows significantly improved performance and durability. The steady-state NOx conversions over new V-SCR were closer to Cu-SCR, especially after aging at 580°C/100h. High durability was also observed after engine aging of 1000h (WHTC + high load). Another big challenge in BS VII could be the PN10 requirement. With enhanced filtration coating (EFC) technology, PN emissions drop drastically in comparison to Euro-VI reference without EFC to meet a future BS-VII.