Multiple direct and indirect methods will need to be utilised in the drive towards emission reduction, with emission control technologies being at the helm
The automotive industry is gearing up to adopt technologies that enable reduced levels of emissions from vehicles, especially since this is one of the most easily blamed industries, when it comes to increasing pollution. The fact that vehicles are visible in large numbers on roads across cities, towns and villages, puts the automotive industry in the limelight. Therefore, we have time and again seen that the automotive industry across the globe consistently attract flak for contributing towards pollution and congestion.
While curbing of emissions was not the primary focus area of the automotive industry over the majority of its existence, this has become the top priority over the last few decades. The western markets, along with mature Asian markets like Japan, have been looking at reducing vehicle tailpipe emissions over a long period of time, for which they have also adopted emission control technologies, which are somewhat standardised. However, India and similar markets have joined this race for cleaner mobility over the last few years, thereby bringing a larger number of participants to the fore.
TECHNOLOGIES CLEANING ICEs
While the move towards alternative sources of power and hybrid powertrain is in progress, there is no doubt that the internal combustion engine (ICE), whether diesel or petrol, will be around for some time. These traditional powertrains have had over a century of development around them, with a lot being done even now. This higher level of advancement of ICEs makes it relatively simpler to introduce technologies that can further reduce the level of polluting gases emitted out of them.
The control of emissions is usually carried out for the exhaust gas aftertreatment of the vehicle, with a few technologies addressed towards fuel management and engine design. Emission control technologies themselves are categorised into catalysts, exhaust gas recirculation (EGR), filters, sensors and thermal management. In terms of engine design technologies to reduce emissions, the most prominent of these are fuel injection, forced air induction and overall design of the combustion chamber itself. Such technologies are employed with an objective of limiting NOx emissions, reducing soot, and improving fuel economy.
The type of lubricants and fuels used also determine the level of emissions that can be expected from an ICE vehicle. Lubricating oils with low viscosity play a critical role in reducing fuel consumption and curbing emissions, but this can only be implemented when the engine is designed to withstand higher levels of wear and tear. On the other hand, fuel additives enhance how the overall fuel burns in the engine, making it burn more completely with lower levels of emissions.
However, the area of exhaust gas treatment is of the highest importance in enabling reduced levels of NOx emissions from vehicles into the atmosphere. The use of components such as catalysts and filters play a significant role in the control of particulate matter and NOx discharge. Diesel engines require higher levels of exhaust gas control than their petrol counterparts in the race towards achieving cleaner emission standards. EGR and Selective Catalytic Reduction (SCR) are the two main technologies that are being adopted in the diesel engine arena to mitigate exhaust gases from vehicles. Meanwhile, petrol engines make use of oxygen sensors, particulate filters and various catalysts to achieve the goal of alleviating emissions.
ALTERNATIVE FUELS & HYBRIDISATION
Moving beyond ICE vehicles, the automotive industry is looking at substitutes to address the sources of power for the vehicle. Numerous years of research and development have boiled down to the fact that electrification would be the most appropriate solution for the future, be it in its pure or in a hybrid form. Other sources of power could be seen in the form of hydrogen fuel cell, compressed natural gas (CNG), liquefied petroleum gas (LPG), solar energy, and various biofuels that work in combination with fossil fuels. However, electric by far seems to be the predominant source that will be widely accepted across the globe.
Barring electricity, all the various sources of alternative energy mentioned, have limitations in the form of infrastructure requirements, high-production costs, and secondary pollution potential. These qualities act as deterrents in adopting any one of those as viable options that can be replaced as primary energy sources for automotive. Electricity, on the other hand, has multiple advantages over other alternative sources of power. Electricity storage for use at a later stage is easy and cost-effective, and the methods being employed to generate it are also getting cleaner, in the form of nuclear reactors and wind power.
Furthermore, ICE vehicles can be hybridised with electric energy more easily and economically than other sources of power. This has led to various forms of hybridisation, namely pure hybrid, plug-in-hybrid and others, used appropriately for the type of vehicle requirement. The fact that increased levels of electronics are being infused into the vehicles of today, which is set to grow further, also works in favour of automotive electrification. Since power electronics are a key part of the EV architecture, the increased electronics content in traditional vehicles makes it easier to implement hybrid powertrains.
A major factor that contributes to the increased adoption of vehicles with hybridised electric powertrains is that it derives the highest performance and efficiency of the powertrain. In essence, this means that the highest potential of the ICE and the electric motor are offered to the driver, thus resulting in superior levels of efficiency combined with a heightened dynamic driving experience. The hybrid electric vehicle of tomorrow could result in cleaner and more-efficient mobility, which does not lack in terms of offering a great driving experience.
While we have covered multiple emission-reduction technologies available in a vehicle, there are certain other techniques of mobility that can be applied to reduce emissions. These techniques can be summarised in the development of mobility to be shared, connected and autonomous. These three trends, which are already gaining momentum in the industry, can contribute significantly towards driving down the level of emissions being presently contributed by the automotive sector.
Making vehicles more connected enable them to communicate with other vehicles, infrastructure, and more importantly users themselves. Transmission of data on factors like road conditions, traffic movement, user requirements and vehicle diagnostics can enable the most-efficient usage of automobiles, which can concurrently enable lowered level of emissions. The story of shared mobility is something that is not new to India, in respect to the packing of multiple people into various modes of first-last mile connectivity as well as public transportation. However, the focus of shared mobility is to bring about some level of organisation, which would then lead to more efficient use of vehicles that are focussed towards carrying multiple passengers towards their individual destinations. Naturally, more efficiency in vehicle usage automatically translates into improved levels of emission reduction.
When it comes to the topic autonomous driving, it should be noted that these technologies are only in their nascent stages even in highly-advanced markets. Therefore, there is much room for development in the area of vehicle autonomy and the role it can play in cutting vehicular emissions. The premise of autonomous vehicles is that they can be easily electrified, more so than ICE vehicles, and can fit in well in enabling advanced levels of connected and shared mobility. Consequently, it enables the trends of vehicle connectivity and sharing to a further degree, which can then indirectly contribute to emissions control.
We are getting close to the implementation of BS VI emission standards in India, which will take the Indian automotive industry closer to emission-conscious global counterparts. While component-level technologies have been developed, and continue to be researched and developed , the move towards future mobility trends of being connected, shared, autonomous and electric will also provide steps in controlling vehicle emissions. Therefore, there will be an overall progress in the development of technologies that will address the future trends of mobility, which are directly related to automotive emission reduction.
(Inputs form Emission Controls Manufacturers Association (ECMA), DieselNet)
TEXT: Naveen Arul