GPF: An Effective Technology to Minimize Two Wheeler (2Wh) Particulate Emission 2024-26-0140

India is the world’s largest two-wheeler (2Wh) market. With the proportion of its middle class rapidly rising, 2Wh sales and the resulting emissions, are expected to grow exponentially. The decision to leap-frog from BSIV to BSVI emission norms shows India’s commitment to clean up its atmosphere. As of now, the regulation mandates Gaseous Pollutant (CO, HC, NO_x) emission limits for all 2Whs and a particulate limit (PM & PN) for 2Whs powered by Direct Injection (DI) engines. Most of the 2Whs manufactured in India are powered by gasoline engines using the Port Fuel Injection (PFI) technology, and hence by definition particulate emission limits do not apply to them. Particulates when inhaled - especially of the ultrafine sizes capable of entering the blood stream - pose a serious health risk. This was the primary motivation to investigate the particulate emission levels of the 2Whs, which as on date, do not come under the purview of BSVI regulation.

A study was conducted selecting a motorcycle each from two different vehicle categories – Class 1 and Class 2-1 – as defined under the Indian 2Wh regulation. In the first phase of testing, emissions from both motorcycles in “as is” condition, were measured under WMTC conditions. While the CVS diluted PN emission for the Class 1 motorcycle was found to be 2.2 X 10¹¹ #/km, the same for the Class 2-1 motorcycle was even higher at 7.0 X 10¹¹ #/km. In the second phase, the emission control system for each of the motorcycles was retrofitted with a Gasoline Particulate Filter (GPF) as an “add-on”, downstream to the “as is” catalytic converter system, and emission tests were repeated. Addition of the GPF reduced the particulate emissions by more than 80%. Thus, the study shows that the particulate emissions from the 2Whs are high enough to adversely impact air quality and advanced emission control solutions like the GPF can effectively minimize the 2Wh particulate emissions.