Carbon Footprint Analysis of Sugarcane Syrup Derived Ethanol Production in an Indian Distillery

Abstract

This study presents a cradle-to-gate assessment of the carbon footprint (CFP) of an ethanol distillery utilizing sugarcane syrup (70° Brix) as the primary feedstock. The evaluation encompasses greenhouse gas emissions from cultivation, fermentation, distillation, dehydration, and associated operations. The total CFP was estimated at 4.42 kg CO₂eq per liter of ethanol including biogenic carbon, and 1.48 kg CO₂eq/L when excluded. The incineration boiler—used to combust concentrated spent wash and bagasse—emerged as the largest emission source (2.18 kg CO₂eq/L). Fermentation contributed 0.755 kg CO₂eq/L, primarily from biogenic CO₂, while sugarcane cultivation accounted for 0.7 kg CO₂eq/L, based on an emission factor of 55 kg CO₂eq per ton of cane. Additional emissions were associated with electricity use in distillation (0.0375 kg), molecular sieve dehydration (0.0101 kg), multi-effect evaporation (0.5487 kg), and CO₂ capture operations (0.0934 kg CO₂eq/L). Transport-related emissions remained below 0.01 kg CO₂eq/L. The study identifies emission hotspots and proposes mitigation strategies including the adoption of hybrid pumping systems, renewable energy integration, and CO₂ valorization. These findings contribute to the development of carbon intensity benchmarks and support India’s ethanol sector in achieving decarbonization goals in line with Sustainable Development Goal 7, particularly targets 7.2 (renewable energy share) and 7.3 (energy efficiency). The results further underscore ethanol’s potential as a scalable and economically viable clean energy alternative within India’s transition framework.