The increasing demand for renewable energy has driven research into sustainable biofuel alternatives. This study evaluates the carbon balance of bioethanol produced from the sap of the Nipa palm (Nypa fruticans), a mangrove species with significant carbon sequestration potential. A cradle-to-grave life cycle assessment was conducted to estimate the total carbon dioxide (CO2) emissions from bioethanol production and compare it with the CO2 absorbed by the Nipa palm. The assessment covered emissions from transportation, fermentation, distillation, and distribution. The findings show that Nipa palms exhibit a substantial CO2 sequestration capacity, averaging 21,785 kg CO2/ha/year. The gate-to-gate emissions for producing 95% hydrous ethanol (H95F) and 99% hydrous ethanol (H99F) were calculated to be 1,075.91 kg CO2/ha and 11,552.94 kg CO2/ha, respectively. By comparing emissions against sequestration, the study reveals a significant positive carbon balance. The net balance for H95F production was -20,709.09 kg CO2/ha/year, and for H99F, it was -10,232.06 kg CO2/ha/year. This indicates that the bioethanol production system from Nipa sap is not only carbon neutral but carbon negative, as the Nipa palm cultivation absorbs more CO2 than the entire production process emits. Furthermore, compared to gasoline, which emits approximately 2.91 kg CO2-eq per liter, Nipa bioethanol presents a much lower carbon footprint. These results underscore the potential of Nipa palm bioethanol as a sustainable and environmentally beneficial fuel source that contributes to mitigating climate change by reducing greenhouse gas concentrations.
Sarfat et al. (Thu,) studied this question.