Super Pyrolysis Gasoline (SPG): Northeast Innovation Turns Plastic Waste into High-Octane Petrol
Agartala, February 02, 2026: As India accelerates its transition towards E20 petrol blending and periodically enforces bans on plastic products, a significant scientific development from the Northeast suggests that a more effective and integrated solution may already be within reach—one that simultaneously addresses fuel quality, plastic pollution, and long-term economic sustainability.
Researchers at the National Institute of Technology (NIT) Agartala have demonstrated that common post-consumer plastic waste can be converted into a high-octane gasoline that not only matches but, in several key parameters, outperforms conventional petrol currently sold at fuel stations. The fuel, produced entirely from discarded plastics, delivers higher efficiency, cleaner exhaust emissions, and full compatibility with existing petrol engines, without requiring any modification to vehicles or infrastructure.
India’s E20 petrol programme, which mandates blending 20 per cent ethanol with petrol, is widely promoted as a step towards cleaner mobility and reduced crude oil imports. However, ethanol blending is accompanied by well-documented limitations. These include lower energy density compared to petrol, reduced mileage, concerns over long-term engine compatibility, and increasing pressure on agricultural land and water resources due to the diversion of crops towards fuel production. The fuel developed at NIT Agartala avoids these compromises altogether. Derived from waste plastics rather than crops, it retains the full energy content of petrol and functions as a true drop-in replacement.
The research team processed polyethylene and polypropylene—the most abundant components of household plastic waste—into what they describe as Super Pyrolysis Gasoline (SPG). These plastics, which dominate municipal waste streams and are among the most difficult to recycle mechanically, were converted through a controlled pyrolysis process optimised to maximise gasoline-range hydrocarbons.
Extensive testing revealed that Super Pyrolysis Gasoline (SPG) achieves an octane rating of 103, exceeding both regular and premium petrol currently available in the market. When evaluated in a modern turbocharged petrol engine, the fuel demonstrated smoother combustion, improved thermal efficiency, and reduced fuel consumption compared to commercially available petrol. Researchers observed more stable ignition behaviour and improved performance under varying engine loads.
Crucially, the work did not remain confined to laboratory-scale fuel characterisation. The plastic-derived gasoline was validated under real engine operating conditions, where it consistently delivered superior performance while significantly reducing emissions. Measurements showed reductions of up to 30 per cent in carbon monoxide, unburnt hydrocarbons, nitrogen oxides, and fine particulate matter. With sulphur content reduced to nearly zero, the exhaust profile comfortably meets prevailing emission standards and offers clear advantages in terms of air quality.
Raj Chakraborty, one of the researchers involved in the study, noted that although plastic pyrolysis has been explored for decades as a recycling route, its wider adoption has remained limited. He explained that most earlier efforts produced intermediate pyrolysis oils that were not directly usable as transportation fuels. “The absence of an end-user-ready product has been the biggest barrier,” he said. “In many cases, the output requires further upgrading and still fails to integrate seamlessly with existing engines and fuel infrastructure. Our work specifically addresses this gap by delivering a finished gasoline-grade fuel.”
