Sustainability evaluation of microalgae biodiesel production process integrated with nutrient close-loop pathway based on emergy analysis method

To make comprehensive assessment on sustainability of microalgae biofuel production process integrated with nutrient close-loop pathways, Emergy Analysis methodology was adopted based on case studies: microalgae biodiesel production integrated with Nutrient Recycling Pathway in Case A and microalgae biodiesel production integrated with Protein Production as By-Product Pathway in Case B. Emergy results show that microalgae biodiesel system integrated with Nutrient Recycling Pathway is more sustainable, and factor analysis shows that water source with higher unit emergy value and electricity with lower one are more favorable to improve sustainability performance of the integrated process. Besides, different generations of biofuel are also assessed by Emergy Analysis method, and the third-generation biodiesel shows the most sustainable potentials than the previous.

Automated summary

By conducting Emergy Analysis on microalgae biodiesel production processes, it is found that systems integrated with Nutrient Recycling Pathway are more sustainable, with water resources and electricity units with higher Emergy values being favorable for sustainability improvement. In addition, third-generation biodiesel shows greater sustainable potentials compared to previous generations.