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The Indian government's ambitious plan to implement 20% ethanol blending in petrol (E20) by 2025 has sparked a debate, pitting the potential environmental benefits and reduced import dependence against concerns about the impact on vehicle performance and maintenance costs. The initiative, driven by the dual goals of curbing carbon emissions and lessening reliance on foreign oil, has raised questions among vehicle owners, particularly those with older models, about the long-term effects of E20 fuel on their vehicles and the potential for increased maintenance expenses. Ethanol, a biofuel derived from plant waste or biomass, acts as an oxygenate when mixed with petrol, facilitating more complete combustion. This theoretically leads to reduced emissions. India's ethanol-blending program sources ethanol from sugarcane-based materials like molasses and sugar, as well as damaged food grains like broken rice and maize. The use of molasses, a byproduct of sugarcane production, highlights the program's attempt to utilize waste products and create a more sustainable fuel source. The process of converting molasses into ethanol involves fermentation, where yeast enzymes break down sugar molecules in the presence of water. This process releases ethanol and carbon dioxide. However, the transition to E20 fuel is not without its challenges. One primary concern revolves around the energy efficiency of ethanol compared to petrol. Ethanol has a lower calorific value, meaning it yields less energy per unit volume. This has led to fears that E20 fuel will result in decreased fuel economy. While the government acknowledges the difference in calorific value, they argue that the overall impact on fuel performance is governed by various factors, including driving habits, maintenance practices, and even air conditioning usage. The octane number, a measure of a fuel's resistance to engine knocking, is another important consideration. Ethanol boasts a higher octane number than petrol, potentially mitigating engine knocking. However, the lower energy content of ethanol means that the engine extracts less energy per litre of blended fuel. Experts like Sudheer Kumar Kuppili suggest that the decrease in mileage from E10 to E20 will be minimal and that the current concerns may be overblown. Instead, the focus should be on ethanol's hygroscopic nature, its tendency to attract and retain water molecules. This property can affect vehicle components and fuel performance in unexpected ways. The potential for corrosion is a significant worry. Ethanol can degrade rubber components in the fuel system, including piping, the fuel tank, injectors, and filters. Water accumulation in the fuel tank, especially in vehicles that are not used regularly, can lead to rust and clog the fuel line, further reducing mileage. Despite these concerns, the government maintains that replacing older rubber parts and gaskets designed for non-blended fuel is a relatively inexpensive and manageable task during routine servicing. Kuppili suggests that moisture accumulation should not be a major problem for newer vehicles (BS-IV or BS-VI compliant) and that in colder regions, fuels are often mixed with additives to prevent freezing. He also argues that regular vehicle use will help evaporate any accumulated moisture due to high engine temperatures. Comparisons with Brazil's ethanol-blending program, which has been running for decades, may not be directly applicable to the Indian context. Brazil utilizes E27 petrol and has a large market for flex-fuel vehicles that can adapt to varying ethanol fractions. Indian vehicles, particularly older models, may not be as readily adaptable to E20 fuel. The electronic control unit (ECU) in an engine is sensitive to fuel content and adjusts accordingly. Older cars may lack this capability, making them incompatible with E20 fuel without modifications. One potential solution involves updating the fuel composition setting in the ECU. However, vehicles without ECUs and injectors, particularly those manufactured before the implementation of BS-VI emission standards in 2020, cannot be easily made compatible with E20 fuel. The blending of ethanol alters the stoichiometric ratio, or air-to-fuel ratio, which affects combustion speed and heat release. Modern vehicles with ECUs can monitor oxygen content and adjust the air-fuel mixture accordingly, leading to reduced pollutant emissions. The ethanol-blending policy has been praised for its potential to enhance energy security and reduce import duties. However, experts suggest that a more gradual and paced implementation may be necessary to address the concerns of vehicle owners and ensure a smooth transition. The principle of recalibration involves adjusting the spark timing in the engine to optimize combustion with E20 fuel. Older vehicles lacking ECUs may require engine recalibration, which can be a costly process. This involves advancing the pressure for combustion and its timing to ensure proper starting and air-fuel mixture maintenance. The debate surrounding the ethanol-blending policy highlights the complexities of balancing environmental goals with economic considerations and the need to address the concerns of stakeholders. A gradual and well-planned implementation, coupled with public awareness campaigns and support for vehicle owners, is crucial for the success of this ambitious initiative. The long-term impact of E20 fuel on the Indian automotive industry and the environment remains to be seen, but careful monitoring and adaptation will be essential for navigating the challenges and realizing the potential benefits of this policy.
Source: Ethanol fuel plan cuts imports, worries motorists. What does science say?