Environmental life cycle assessment and energy-economic analysis in different cultivation of microalgae-based optimization method

Abstract

The novelty of this study lies in its comprehensive exploration of microalgae cultivation methods, using energy-economic analysis and life cycle assessment (LCA) techniques, along with data envelopment analysis (DEA) to optimize energy and environmental impacts. The study provides insights into the energy requirements, productivity, net return, and environmental impacts of two common cultivation methods, open space and greenhouse. Results show that open space and greenhouse methods require an average input energy of 15920.40 and 17691.60 MJ kg−1, respectively, with energy ratios of 0.89 and 0.80 and productivity energy indexes of 0.06 and 0.02 kg MJ−1, respectively. The net return of open space and greenhouse methods is 204376.59 and 269276.06 ($ kg−1), productivity of 0.17 and 0.16 (kg $−1), respectively. The ReCiPe 2016 method is used to calculate environmental effects, with resource impact categories ranging from 201.11 to 205.68 USD2013. In terms of damage assessment categories, water and machinery and equipment have the highest share of damage assessment in both cultivation methods. DEA shows that total optimal energy consumption in the open space method is 14476.93 (MJ kg−1), resulting in a 7.55% decrease in energy consumption compared to the current cultivation. This is achieved by converting inefficient to efficient cultivation.