Evaluation of Cleaning Effect of Diesel Particulate Filter Used in BSVI Compliant Vehicle in Polluted Urban Environment w.r.t Particulate Mass and Particulate Number.

Air pollution is by far the highest cause of health risks in many countries across the globe, including India. Stricter emission regulations and other measures are being sincerely enforced in India to effectively reduce the air pollution. Implementation of BS6 emission regulation in India on the fast track has been one of the greatest achievements combining advanced technologies for engine efficiency improvement and tail-pipe emission reduction and also bringing controls on real-life on-road emissions (Real Drive Emissions - RDE) from vehicles.

Electrification in transportation is being pushed hard to displace conventional fossil-fuel based IC Engine vehicles, specially diesel vehicles, since diesel carries an image of emitting higher emissions of PM and NOx compared to other fuels and, therefore, is not considered as a clean fuel. In spite of the fact that diesel is a well-known versatile, powerful, efficient and durable prime mover for all kinds of transport and stationary applications; higher emissions of PM and NOx rides over its aforementioned benefits.

project

However, latest available advanced exhaust after treatment technologies employed in BS6 diesel vehicles; such as DPF, SCR, ASC, etc ensuring conversion efficiencies up to 95%; have demonstrated a great potential to reduce tail pipe emissions of NOx and PM (both mass and number) to an extent of almost near-zero level and competes well with its counterpart gasoline emission levels.

As regards to health risks to human beings due to particulate emissions (PM), it is the fact that ultrafine particles can penetrate deep into the respiratory system and even enter the blood stream causing high risks. Fine particles of some mass is less hazardous than several ultrafine particles. Therefore, engine emissions based on particle mass is not protective, hence, the new emission regulations include measurement and control of particle number. It is experimentally revealed that a well-optimised PM filter (DPF) not only reduces the particulate mass emissions (PM) at the vehicle tail-pipe exiting to the environment to near-zero level but it is also observed that particle number (PN) at the tail-pipe are also significantly lower than that exist in the polluted ambient air that the vehicle engine sucks for combustion.

A study project conducted by ECMA on a BS6 Light Duty Diesel vehicle clearly and significantly endorses the above fact. That means in reality, PM Filter fitted in a BS6 diesel vehicle has experimentally shown a great contribution in cleaning the polluted ambient air both in laboratory testing and Real Driving Emission (RDE) testing on-the-road as well. Based on these results, it can be confidently stated that a PM Filter technology would be presenting similar trend when fitted in advanced diesel engines for any application – light, medium and heavy-duty vehicles, agricultural tractor, CEVs, stationary gensets, locomotives, marines, etc.

Referring to the experimental data, it can be inferred that if more and more advanced technology diesel vehicles ply on the road as well as off-road applications with PM Filters and NOx abatement technologies, they would very effectively clean the polluted ambient air, specially the particulate mass and number, which is of great concern to human health issues. What is more interesting to note that the BS6 Diesel PM Filters will not only reduce tail-pipe emissions of PM and PN to near-zero level much below even BS6 limits, but would grossly work on cleaning the ambient air which is polluted severely and significantly from other sources such as construction dust, road-side dust, industry pollution, crop burning, desert dust, etc; which are not otherwise handled by any technique effectively. Cleaner Ambient Air would be a boon to the human beings to help get cleaner air for breathing. It could also be noted that on similar lines Gasoline Particulate Filters employed on advanced SI IC engines would also do the same job in ambient air filtration.

This topic and experimental results discussed here could be controversial in the present context, but we see a great significance as a potential solution to arrest the increasing trend of the ambient air pollution and providing a cleaner air for breathing.

The proposed Round-Table meeting will be focused to present and discuss the results to the Group of a Panel comprising of Policy and Rule makers, technology authorities and experts, and other related stake-holders coming from different knowledge fields and experiences.

The central objective of the proposed Round-Table meeting would be to discuss the perspectives and explore the probable actions related to the opportunities for advanced diesel engines and associated advanced emission control technologies and their potential to effectively clean the ambient air environment besides reducing other tail-pipe emissions to near-zero level, specially attending the significant control on particulate mass and particle number too, leading to effectively state that “BS6 PM Filters have a great dual-potential to provide clean air for breathing effectively cleaning the surrounding Ambient Air polluted by different sources and in addition to reduce vehicle tail-pipe emissions itself to near-zero levels”.

Round Table Meeting

A Round Table Meeting was conducted at India Habitat Centre, New Delhi on 28th August 2024 to present and discuss the highlights of the Project results. More than 35 dignitaries participated in the Round Table.

The joint presentation, given by ECMA and ARAI, about the study project done on a BS6, OBD-I, Diesel SUV revealed that –

project
  • PM and PN emissions at the vehicle tail-pipe have been more or less constant and well below BS6 legislative limits with varying AQI PM2.5 levels at the Vehicle inlet, and demonstrated this trend at both laboratory level CD tests as per MIDC and during on-road tests comprising of city-road tests in morning and afternoon time and also during RDE tests as per certification procedure.
  • There looks to be a promising opportunity for particle filters to achieve near-zero ultra-low level PM and PN emissions at the vehicle tail-pipe, be it used in any category of vehicle such as LMV, LCV, MCV, HCV, off-road, stationary power generation etc, using any type of fuel such as diesel, gasoline, CNG, etc
  • Modern BS6 and beyond diesel engines equipped with robust exhaust treatment devices such as advanced particle filters provide ultra-clean diesels more or less the levels of PM and PN emissions of gasoline engines, hence, carries a bright future for emission controls and air quality improvement, however, older and emitting vehicles need to be replaced.
  • Study also reveals that potentially the particle filters are probably acting like a ambient air filtering system.
project