Bolivia's Path to Lower Emissions: Sugar Cane Ethanol and GREET Model Insights into Ethanol-Gasoline Blends.

Bolivia's transition toward sustainable energy is advancing through the integration of sugar cane ethanol as a viable alternative to fossil fuels. This study presents the first gate-to-gate (GtG) life cycle assessment (LCA) of Bolivian ethanol production, developed using Aspen Plus v14 with a base unit of 1 MJ of energy. The assessment considers a sugar cane milling capacity of 23,000 tons per day and an annual production potential of 108 million liters of anhydrous ethanol. Distillation emerged as the most significant contributor to the GtG global warming potential (GWP) at 31.0 gCO2eq/L; however, ethanol's life-cycle emissions were significantly lower (1.61 gCO2eq/MJ) than gasoline (70.74 gCO2eq/MJ). Complementarily, a tank-to-wheel (TtW) LCA was conducted using the GREET model and a functional unit of 1 km traveled, to evaluate the impact of ethanol-gasoline blends on Bolivia's national vehicle fleet from 2022 to 2028. Results show that an E25 blend could reduce GHG emissions by up to 11.2% in passenger cars, 13.2% in SUVs, and 15.2% in pick-up trucks by 2028. Significant reductions in carbon monoxide (25.1%) and volatile organic compounds (21.0%) also enhance air quality. Economic analysis demonstrated a net present value of 202.94 million USD and an internal rate of return of 7.93%, reinforcing ethanol's profitability and strategic value in Bolivia's low-carbon transition.