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 –
- 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.