Context
- The Automotive Research Association of India (ARAI) is conducting a pilot project to explore isobutanol blending with diesel, following the limited success of ethanol–diesel blending.
- The project aims to:
- Develop cleaner-burning fuels for the transport sector.
- Reduce crude oil imports and enhance energy security.
- Utilize surplus ethanol feedstock effectively.
- Support India’s Net-Zero 2070 goals.
About Isobutanol
1. What it is
- Chemical formula: C4H10O
- Type: Four-carbon alcohol, clear, flammable liquid
- Energy content: Higher than ethanol, making it more efficient as a fuel
- Current uses: Solvent in paints, coatings, chemical synthesis, and emerging as a biofuel blendstock
2. Formation Process
- Produced by fermenting natural sugars like cane juice, molasses, and grains using genetically engineered microbes.
- Requires sterile fermentation conditions.
- Sugar refineries need:
- Fermentation tank retrofitting
- Distillation units to separate ethanol and isobutanol
- Can be co-produced with ethanol using existing infrastructure with minor modifications
3. Aim of Blending
- Create a cleaner-burning diesel blend to reduce emissions.
- Reduce crude oil imports and enhance energy security.
- Provide a market for surplus ethanol, supporting the sugar sector’s sustainability.
- Contribute to India’s Net-Zero 2070 vision.
4. Key Features
- Higher Flash Point: Safer than ethanol, less volatile, reduces fire risk.
- Better Miscibility: Blends uniformly with diesel without extra additives.
- Energy-Dense: Higher calorific value than ethanol → improved fuel efficiency.
- Flexible Production: Co-produced with ethanol using minor refinery modifications.
- Emission Benefits: Potential to lower particulate emissions and reduce carbon intensity.
5. Applications
- Transport Sector: Up to 10% blend with diesel recommended.
- Solvent Industry: Paints, coatings, and chemical synthesis.
- Aviation & Marine Fuel: Research ongoing for sustainable fuel alternatives.
- Chemical Feedstock: Conversion into jet fuel, plastics, and rubber intermediates.
6. Limitations & Challenges
- Low Cetane Number: May reduce ignition quality → potential engine knocking.
- Engine Compatibility: Blends beyond 10% may impact performance and durability.
- Incremental Cost: Additives and blending infrastructure upgrades increase costs.
- Miscibility Issues: Full homogeneity may require biodiesel as a co-solvent.
Conclusion
- Isobutanol is a promising biofuel for diesel blending in India, offering:
- Safer handling, better miscibility, and higher energy density compared to ethanol.
- Challenges like engine compatibility, costs, and miscibility need to be addressed.
- Successful implementation can:
- Reduce fossil fuel dependence
- Strengthen the sugar–ethanol ecosystem
- Contribute significantly to Net-Zero 2070 targets
Source : The Hindu
