Syllabus:

GS-3: Infrastructure: Energy, Ports, Roads, Airports, Railways etc.  

GS-3: Conservation, environmental pollution and degradation, environmental impact assessment 

Context:

Recently, the Union Transport Minister held the Automotive Research Association of India (ARAI) is exploring the possibility of blending isobutanol with diesel.

More on the News

• The blending paradigm is still being studied and the pilot project would take about 18 months to complete.
• If successful, India would be the first country to have blended isobutanol with diesel.

Isobutanol

• Isobutanol is an alcoholic compound with inflammable properties and is used as a solvent in several industries, including painting. 
• It is primarily used as a solvent and a biofuel additive due to its higher energy density and lower hygroscopicity compared to ethanol.

Advantages 

• Higher Energy Density than Ethanol: Closer to diesel in terms of energy per litre, which implies less reduction in fuel efficiency when blended.
• Lower Hygroscopicity: Reduced risk of moisture absorption, which means less corrosion of pipelines, tanks, and fuel delivery infrastructure.
• Emissions Benefits: Potential for reduced particulate matter and soot emissions, since bio-alcohols generally burn cleaner in some respects.
• Use of Waste Biomass: If sourced sustainably, feedstock for isobutanol can add value to waste streams, increase farmer incomes, and reduce environmental costs.

Challenges 

• Cetane Number & Combustion Characteristics: Isobutanol has a lower cetane number than pure diesel. Lower cetane means longer ignition delay, which can adversely affect combustion efficiency, engine noise, emissions. 
• Miscibility Problem: Isobutanol and diesel may have issues on miscibility. Miscibility is the property of two or more substances to completely mix in all proportions to form a homogeneous mixture.
• Knocking Problem: ‘Knocking’ occurs when the fuel burns unevenly, prematurely in the vehicle’s fuel cylinder. A lower cetane number raises concerns about ‘diesel knock’ which can result in reduced power and can potentially damage engines.
• Infrastructure and Engine Compatibility: Diesel engines are designed for specific combustion and ignition parameters. Use of blended fuel could require re-calibration of engines, modifications in fuel systems, seals, storage, transport, and handling facilities.
• Emission Trade-Offs: While some pollutants may reduce, others could increase. For instance, carbon monoxide, HC, or NOx emissions need careful measurement. The net environmental benefit depends on blend ratio, engine design, and overall life-cycle of the fuel.
• Cost & Scale Limitations: Producing bio-isobutanol at scale at competitive costs remains a challenge. Feedstock procurement, production technology, logistics, and policy incentives are crucial.

Way Forward 

• Pilot Blending & Testing: Set up more pilot projects to find optimal blend percentages that balance emissions, performance, and cost.
• Engine Testing & Calibration: Automotive Research bodies need to collaborate with Original Equipment Manufacturers (OEMs) to test engines for blended fuels and redesign or calibrate where needed.
• Standards & Regulation: Develop fuel quality standards, emissions standards for blends, infrastructure safety norms.
• Incentives & Investment: Subsidies, tax incentives, or financing for biofuel production, R&D, infrastructure adaptation.
• Sustainability of Feedstock: Ensure that feedstock does not compete with food production or lead to land-use changes with negative environmental impacts.

Sources:
The Hindu
Financial Express