Yanfen,L., Zehao,H. and Xiaoqian,M.(2012): Energy analysis and environmental impacts of microalgal biodiesel in China. Energy Policy, 45, 142-151.

『中国における微細藻類バイオディーゼルのエネルギー分析と環境影響』


Abstract
 The entire life cycle of biodiesel produced by microalgal biomasses was evaluated using the method of life cycle assessment (LCA) to identify and quantify the fossil energy requirements and environmental impact loading of the system. The life cycle considers microalgae cultivation, harvesting, drying, oil extraction, anaerobic digestion, oil transportation, esterification, biodiesel transportation and biodiesel combustion. The investigation results show that the fossil energy requirement for the biodiesel production is 0.74 MJ/MJ biodiesel, indicating that 1 MJ of biodiesel requires an input of 0.74 MJ of fossil energy. Accordingly, biodiesel production is feasible as an energy producing process. The environmental impact loading of microalgal biodiesel is 3.69 PET2010 (Person Equivalents, Targeted, in 2010) and the GWP is 0.16 kg CO2-eq/MJ biodiesel. The effects of photochemical ozone formation were greatest among all calculated categorization impacts. The fossil energy requirement and GWP in this operation were found to be particularly sensitive to oil content, drying rate and esterification rate. Overall, the results presented herein indicate that the cultivation of microalgae has the potential to produce an environmentally sustainable feedstock for the production of biodiesel.

Keywords: Life cycle assessment; Miocroalgae; Biodiesel』

1. Introduction
2. Methodology
 2.1. Overall approach
 2.2. Definition of goal and scope
3. Unit process and life cycle inventory
 3.1. Data collection and validation of data
 3.2. Cultivation and treatment of microalgae
  3.2.1. Cultivation of microalgae
  3.2.2. Harvesting
  3.2.3. Drying
 3.3. Microalgal oil extraction and refining
 3.4. Transport of microalgal oil and biodiesel
 3.5. Anaerobic digestion and biogas combustion
 3.6. Esterification
 3.7. Biodiesel combustion
4. Impact assessment
 4.1. Energy consumption
 4.2. Environment impact assessment
  4.2.1. Characterization
  4.2.2. Normalization and weighting
5. Sensitivity analysis
6. Discussion
7. Conclusions
Acknowledgments
References


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