On Monday, Prime Minister Narendra Modi launched a pilot for ‘E20’, or petrol blended with 20% ethanol, at the ‘India Energy Week’ in Bengaluru, bringing forward by two years the launch of a cleaner-burning version of petrol. TOI does a deep dive:
What Is Ethanol Blending? Ethyl alcohol or ethanol (C2H5OH) is a biofuel that is made naturally by fermenting sugar derived from sugarcane or other organic matter like foodgrains. As part of its carbon reduction commitments, India has launched the Ethanol Blended Petrol (EBP) programme to mix this biofuel with petrol to reduce the consumption of petrol. India has already met its E10 target, so petrol used in the country has 10% ethanol in it. The E20 pilot covers at least 15 cities and will be rolled out across the country in a phased manner. Why Increase Blending? India imported 185 million tonnes of petroleum at a cost of $551 billion in 2020-21. As most of the petroleum products are used in transportation, a successful E20 programme can save the country $4 billion or Rs 30,000 crore per annum. “Besides, ethanol is a less polluting fuel, and offers equivalent efficiency at a lower cost than petrol,” says a report by a special expert committee set up by the Centre. “Availability of large arable land, rising production of foodgrains and sugarcane leading to surpluses, availability of technology to produce ethanol from plant based sources, and feasibility of making vehicles compliant to ethanol-blended petrol make E20 not only a national imperative, but also an important strategic requirement,” it says. What Research Shows An Indian study on the suitability of using E20 in existing vehicles found: “metals and metal coatings had no issue with E20. Elastomers h ad inferior performance with E20 compared to neat gasoline. Plastic PA 66 had a drop in tensile strength after use with E20. ” Automotive Research Association of India (ARAI), Indian Institute of Petroleum (IIP) and Indian Oil Corpo-ration (R&D) that did the research in 2014-15 also found that fuel economy decreased by up to 6% (depending on the vehicle type), o n average. However, the test vehicles passed startability and drivability tests under hot and cold conditions with pure petrol and E20 test fuels. In all the cases, there was no severe malfunction or stall observed at any stage of vehicle operation. No abnormal wear of engine components or deposits or deterioration of engine oi ls were observed after the on-road mileage accumulation trials. Joint studies reported by the Massachusetts Institute of Technology (MIT) and Honda R&D indicate improvement in relative efficiency up to 20% can be achieved with E20 compared with normal gasoline when the engine is properly tuned. Trials by Ford Motor Company concluded an engine optimised for E20 fuel showed comparable volumetric fuel economy (mileage) and range (kilometres travelled on a single fill) of normal gasoline with a CO2 reduction of 5%. Environmental Impact Pointing out that vehicular e missions such as carbon monoxide (CO), hydrocarbons (HC) and oxides of nitrogen (NOx) are currently under regulation in India, the Central committee’s report argues that ethanol-blended gasoline decreases these emissions. “Higher reductions in carbon monoxide emissions were observed with E20 fuel – 50% lower in two-wheelers and 30% lower in four-wheelers. Hydrocarbon emissions are reduced by 20% with ethanol blends compared to normal gasoline. Nitrous oxide emissions did not show a significant trend as it depended on the vehicle/engine type and engine operating conditions,” the report said. The unregulated carbonyl emissions, such as acetaldehyde, were higher with E10 and E20 compared with normal gasoline due to the presence of hydroxyl groups in ethanol. However, these emissions were relatively minor (a few micrograms) compared with regulated emissions (which were in grams). Evaporative emission test results with E20 fuel were similar to neat petrol. “Overall, ethanol blending can help decrease emission s from both two-wheelers and four-wheelers,” the report added.