Delhi becomes first city to roll-out BS-VI fuel

• New Delhi has become the first city in India to deploy Bharat Stage 6 Fuel for both petrol and diesel.
• The idea behind this implementation two years ahead of the previously scheduled date of April 1, 2020, is to help battle Delhi’s long-standing terminal pollution problem.

What are BS norms?

• Bharat Stage emission standards, introduced in 2000, are emission standards that have been set up by the Central government to regulate the output of air pollutants from internal combustion engine equipment, including motor vehicles.
• The different norms are brought into force in accordance with the timeline and standards set up by the Central Pollution Control Board which comes under the Ministry of Environment and Forests and Climate Change.
• The move from BS-IV or Euro 4 to BS VI will require significant investment in technologies like Diesel Particle Filter (DPF) and Selective Catalytic Reduction (SCR). DPF, which comes under BS-V norms will now incorporated in BS-VI vehicles. In stage VI, selective catalytic reduction technology has to be optimized.

DPF (Diesel Particulate Filter)

• The diesel particulate filter (DPF) for removing particulate matter is a cylindrical object that has to be mounted inside the engine compartment.
• In India, where small cars are preferred, fitting DPF into the limited bonnet space would involve major redesign. The bonnet length may have to be increased, which would make vehicles breach the prevalent excise bracket for sub-4 metre cars.
• The DPF would further have to be optimised for Indian operating conditions
• In Indian conditions, low driving speed means it is difficult to achieve temperatures of 600°C required to burn the soot in DPF. Usually diesel is injected to increase temperatures but excess fuel can cause a fire.
• The injection rate has to be optimised, vehicles re- engineered keeping in mind safety.

SCR (Selective Catalytic Reduction)

• The selective catalytic reduction (SCR) module is used to reduce oxides of nitrogen. When the exhaust is moving, an aqueous urea solution (AUS 32) is injected into the system.
• AUS 32 contains ammonia, which reacts with and reduces the nitrogen. This means a container needs to be put on board the car for deploying the AUS 32.
• Separately, infrastructure also needs to be set up across the country for supply of AUS 32. The optimisation and fitment of this technology would again take three to four years.

By: Vishal