**2. Regulatory development in diesel engine emission**

Stringent diesel exhaust emission regulatory policies have been in operation in the United States and Japan since 2005. The European Union has also responded with additional emission regulatory standards called the EURO VI since 2014. Apart from these regulatory controls, there are market and political pressures on automobile manufacturers to continue to improve on efficiency while reducing emissions. These factors have been the driving force behind the significant technological progress in engine research and the transport industry in the past two decades.

#### **2.1 Heavy duty diesel regulatory developments**

The European Union commission on emissions in 2014 stipulated that the nominal NOX emission limit must be 0.20 g/kWh<sup>−</sup><sup>1</sup> and the PM emission level must be 0.010 g/kWh<sup>−</sup><sup>1</sup> . This matched the US 2010 emission regulation, which put the emission limits at 0.26 g/kWh<sup>−</sup><sup>1</sup> for NOX and 0.013 g/kWh<sup>−</sup><sup>1</sup> for PM emissions. The Japanese emissions regulation of 2009 stipulates 0.7 g/kWh<sup>−</sup><sup>1</sup> for NOX emissions and 0.010 g/kWh<sup>−</sup><sup>1</sup> for PM emissions. However, it must be mentioned here that each of these countries propose a different transient testing cycle.

The European Union commission on pollution and emission has adopted a new world harmonized transient cycle (WHTC) that uses higher load and speed than the Japanese and American standards. Additionally, the European commission on emissions has set standards related to number-based PM standards with heavier in-use compliance measures as illustrated in **Figure 3**, by 2012. These measures are aimed at improving fuel economy and durability and lowering the cost of manufacturing and maintenance. The development in this segment is muted, mixed with conservatism and pragmatism. For example, the development in HD since 2004 has seen the US regulations matched and addressed through advanced EGR and intake charge boosting measures. However, later development starting from 2005 in Japan and 2007 in the United States has seen additional technologies added to cater for increased regulation. These two markets introduced diesel particulate filters (DPFs) to match the change in policy and regulation in the European Union with implementation of EURO V-VI emission regulations. This policy shift and regulation change has witnessed conventional engine technology adding the selective catalytic

**39**

**Figure 4.**

*Effects of Biodiesel Blends Varied by Cetane Numbers and Oxygen Contents on Stationary Diesel…*

reduction (SCR) system in the fight against emission. Since 2009 and 2010, respectively, Japan and the United States have added significant incremental advances in emission compliant technologies, especially technologies that target low load emissions in HD engines. Researchers working on the traditional diesel combustion hardware and strategies are directing more effort to reduce LD engine category

*Progress toward meeting the European Union voluntary CO2 limits of the European Automobile Manufacturers Association (ACEA), Japan Automobile Manufacturers Association (JAMA), and Korea Automobile* 

Modern diesel engine development is driven by regulatory, market, and fuel efficiency demand. In addition, developments in spark ignition (SI) gasoline engines, electric vehicles, and new concepts in hybrid vehicles have had tremendous competitive pressure on diesel engine development, especially in the LD category. Diesel engine manufacturers are responding with the introduction of advanced fuel injection technology, exhaust gas recirculation (EGR) techniques,

*Variation of flame equivalence ratio, temperature, and injection strategies and principles of advanced* 

*DOI: http://dx.doi.org/10.5772/intechopen.92569*

emissions with the future looking bright.

**Figure 3.**

**2.2 Light duty diesel regulatory development**

*combustion (courtesy of Sandia National Laboratory) [44, 45].*

*Manufacturers Association (KAMA) (courtesy of Daimler Chrysler) [40].*

*Effects of Biodiesel Blends Varied by Cetane Numbers and Oxygen Contents on Stationary Diesel… DOI: http://dx.doi.org/10.5772/intechopen.92569*

#### **Figure 3.**

*Numerical and Experimental Studies on Combustion Engines and Vehicles*

**2. Regulatory development in diesel engine emission**

*Variation of NOx emission with the regulatory limit for 45 US states [33].*

**2.1 Heavy duty diesel regulatory developments**

nominal NOX emission limit must be 0.20 g/kWh<sup>−</sup><sup>1</sup>

Japanese emissions regulation of 2009 stipulates 0.7 g/kWh<sup>−</sup><sup>1</sup>

each of these countries propose a different transient testing cycle.

be 0.010 g/kWh<sup>−</sup><sup>1</sup>

**Figure 2.**

and 0.010 g/kWh<sup>−</sup><sup>1</sup>

emission limits at 0.26 g/kWh<sup>−</sup><sup>1</sup>

Stringent diesel exhaust emission regulatory policies have been in operation in the United States and Japan since 2005. The European Union has also responded with additional emission regulatory standards called the EURO VI since 2014. Apart from these regulatory controls, there are market and political pressures on automobile manufacturers to continue to improve on efficiency while reducing emissions. These factors have been the driving force behind the significant technological progress in engine research and the transport industry in the past two decades.

The European Union commission on emissions in 2014 stipulated that the

. This matched the US 2010 emission regulation, which put the

for PM emissions. However, it must be mentioned here that

for NOX and 0.013 g/kWh<sup>−</sup><sup>1</sup>

The European Union commission on pollution and emission has adopted a new world harmonized transient cycle (WHTC) that uses higher load and speed than the Japanese and American standards. Additionally, the European commission on emissions has set standards related to number-based PM standards with heavier in-use compliance measures as illustrated in **Figure 3**, by 2012. These measures are aimed at improving fuel economy and durability and lowering the cost of manufacturing and maintenance. The development in this segment is muted, mixed with conservatism and pragmatism. For example, the development in HD since 2004 has seen the US regulations matched and addressed through advanced EGR and intake charge boosting measures. However, later development starting from 2005 in Japan and 2007 in the United States has seen additional technologies added to cater for increased regulation. These two markets introduced diesel particulate filters (DPFs) to match the change in policy and regulation in the European Union with implementation of EURO V-VI emission regulations. This policy shift and regulation change has witnessed conventional engine technology adding the selective catalytic

and the PM emission level must

for PM emissions. The

for NOX emissions

**38**

*Progress toward meeting the European Union voluntary CO2 limits of the European Automobile Manufacturers Association (ACEA), Japan Automobile Manufacturers Association (JAMA), and Korea Automobile Manufacturers Association (KAMA) (courtesy of Daimler Chrysler) [40].*

reduction (SCR) system in the fight against emission. Since 2009 and 2010, respectively, Japan and the United States have added significant incremental advances in emission compliant technologies, especially technologies that target low load emissions in HD engines. Researchers working on the traditional diesel combustion hardware and strategies are directing more effort to reduce LD engine category emissions with the future looking bright.

#### **2.2 Light duty diesel regulatory development**

Modern diesel engine development is driven by regulatory, market, and fuel efficiency demand. In addition, developments in spark ignition (SI) gasoline engines, electric vehicles, and new concepts in hybrid vehicles have had tremendous competitive pressure on diesel engine development, especially in the LD category. Diesel engine manufacturers are responding with the introduction of advanced fuel injection technology, exhaust gas recirculation (EGR) techniques,

#### **Figure 4.**

*Variation of flame equivalence ratio, temperature, and injection strategies and principles of advanced combustion (courtesy of Sandia National Laboratory) [44, 45].*

two-stage turbocharging, variable valve actuation, closed loop combustion control, and advanced model-based controls. Development in advanced diesel engines has now achieved a specific output of 70 kW<sup>−</sup><sup>1</sup> and a brake mean effective pressure (BMEP) of 24 bars [41], hence meeting EURO VI emission standards [42, 43] as shown in **Figure 4**.
