Emergy analysis of agricultural waste biomass for energy-oriented utilization in China: Current situation and perspectives

Agricultural waste biomass (AWB) is becoming a significant sustainable alternative for fossil fuels. Emergy analysis (EmA) is a promising methodology that provides a uniform standard to assess simultaneously the environmental load and economic returns of a system. Relevant studies on the assessment of AWB energy-oriented utilization by EmA are attracting researchers' attention worldwide. Therefore, this paper aimed to comprehensively review state-of-the-art applications of the EmA for AWB energy-oriented utilization systems. Results indicated that there were limitations and challenges in the application of single EmA. Importantly, the boundary of AWB energy-oriented utilization systems in the application of EmA was not unified, leading to poor comparability of the impact results. Although the effect of policies has a significant influence on the application and promotion of AWB energy-oriented utilization, the EmA method can hardly reflect the effect of policies. Therefore, there is a need in combination with other methods to optimize the EmA, thus providing comprehensive guidance for decision-makers. Finally, based on these, some feasible suggestions especially to (1) further promote the application and (2) development of this research field were presented. It is hoped that this work could support the proper evaluation and further optimization of AWB energy-oriented utilization systems.