India has just launched the high efficiency BS VI grade of petrol and diesel in a bid to cut vehicular emissions. However, However, the improved fuel quality will have a marginal impact on emissions until the launch of the complimentary BS VI compliant automobile engines, SSV Ramakumar, Director-R&D at Indian Oil Corporation (IOC), the nation’s largest fuel retailer, said in an exclusive interview with Bilal Abdi. He also explains the key difference between BS IV and BS VI fuel and the changes carried out by Oil Marketing Companies (OMCs) for producing the greener fuel. Edited excerpts..
What is BS-VI fuel and what makes it advantageous over the earlier grades?
BS-VI is an ultra-clean fuel qualifying the stringent fuel quality parameters. The sulphur content in BS VI fuels has been reduced to 10 ppm from 50 ppm (in BS-IV). The lower sulphur in the fuel will permit the use of advanced after treatment devices (ATDs) used for reducing harmful exhaust emissions like CO, HC, NOx and Particulate Matter. With the use of these fuels, PM and HC emissions from heavy duty vehicles would reduce by 50 % and 65% respectively. The efficacy and durability of Diesel Particulate Filter (DPF) and Selective Catalytic Reduction (SCR) will increase with the use of BS VI fuels
In terms of vehicular emissions, what is the key difference between BS IV and BS VI fuel?
The lower sulphur content in the BS-VI fuel will facilitate use of after treatment devices to meet the tighter emission norms. The poly-aromatic hydrocarbons (PAH) in diesel fuel has been reduced to 8% in BS VI compared to 11% in BS IV (thus reducing carcinogenic emissions). BS VI fuels are going to significantly reduce the Greenhouse gas emissions especially the Carbon dioxide, unburnt hydrocarbons or methane and oxides of nitrogen. With Global Warming Potential (GWP) of 310, Oxides of nitrogen (NOx) are considered to be critical species in promoting the Global Warming. For heavy duty vehicles, the BS VI diesel would produce 89% lower NOx emissions and 50% lower PM emissions as compared to BS IV. This, coupled with 72% reduction in hydrocarbon emissions, will have a knock-down effect on CO2 emissions. For the gasoline passenger cars, 25% reduction would be achieved in NOx while diesel passenger cars would be emitting 68% and 82% lower NOx and PM emissions respectively. Further, BS VI norms propose stringent regulations on CH4 emissions for CNG vehicles and the latest CAFE (Corporate Average Fuel Economy) standards have been affected from April 2017 in order to limit CO2 . Read More…