Life cycle water consumption of bio-oil fermentation for bio-ethanol production based on a distributed-centralized model

Life cycle water consumption of bio-ethanol production via bio-oil direct fermentation or indirect fermentation based on a distributed-centralized model was investigated. The life cycle water consumption results separately are 202 and 888 L water per GJ bio-ethanol for bio-oil indirect fermentation, and 206 and 2200 L water per GJ bio-ethanol for bio-oil direct fermentation when the economic value-based allocation method and the process purpose-based method are separately used. 32 different parameters related to material use, energy consumption, waste emission, and product yields were varied in a sensitivity analysis. The sensitivity analysis shows bio-ethanol yield and co-product yield have the greatest impact on the life cycle water consumption results. Ac-cording to an uncertainty analysis, the maximum and minimum water consumption results separately are 1225 (the process purpose-based method) and 156 L water per GJ bio-ethanol (the economic value-based allocation method) for bio-oil indirect fermentation. A contribution analysis shows that the distributed-centralized model can really contribute to a slight reduction in water consumption in comparison with the non-distributed model. Overall, bio-ethanol production via bio-oil indirect fermentation based on the distributed-centralized model is green and clean from the standpoint of water resource consumption.

Automated summary

This study investigates the life cycle water consumption of bio-ethanol production through bio-oil direct or indirect fermentation based on a distributed-centralized model. The results show that bio-oil indirect fermentation consumes 202 and 888 L water per GJ bio-ethanol, while bio-oil direct fermentation consumes 206 and 2200 L water per GJ bio-ethanol, depending on the allocation method used. Sensitivity analysis reveals that bio-ethanol yield and co-product yield have the greatest impact on water consumption. The distributed-centralized model contributes to a slight reduction in water consumption compared to the non-distributed model.