Exergetic Life Cycle Assessment: A Review

Exergy is important and relevant in many areas of study such as Life Cycle Assessment (LCA), sustainability, energy systems, and the built environment. With the growing interest in the study of LCA due to the awareness of global environmental impacts, studies have been conducted on exergetic life cycle assessment for resource accounting. The aim of this paper is to review existing studies on exergetic life cycle assessment to investigate the state-of-the-art and identify the benefits and opportunity for improvement. The methodology used entailed an in-depth literature review, which involved an analysis of journal articles collected through a search of databases such as Web of Science Core Collection, Scopus, and Google Scholar. The selected articles were reviewed and analyzed, and the findings are presented in this paper. The following key conclusions were reached: (a) exergy-based methods provide an improved measure of sustainability, (b) there is an opportunity for a more comprehensive approach to exergetic life cycle assessment that includes life cycle emission, (c) a new terminology is required to describe the combination of exergy of life cycle resource use and exergy of life cycle emissions, and (d) improved exergetic life cycle assessment has the potential to solve characterization and valuation problems in the LCA methodology.

Waste-to-energy: A review of life cycle assessment and its extension methods

This article proposes a comprehensive review of evaluation tools based on life cycle thinking, as applied to waste-to-energy. Habitually, life cycle assessment is adopted to assess environmental burdens associated with waste-to-energy initiatives. Based on this framework, several extension methods have been developed to focus on specific aspects: Exergetic life cycle assessment for reducing resource depletion, life cycle costing for evaluating its economic burden, and social life cycle assessment for recording its social impacts. Additionally, the environment–energy–economy model integrates both life cycle assessment and life cycle costing methods and judges simultaneously these three features for sustainable waste-to-energy conversion. Life cycle assessment is sufficiently developed on waste-to-energy with concrete data inventory and sensitivity analysis, although the data and model uncertainty are unavoidable. Compared with life cycle assessment, only a few evaluations are conducted to waste-to-energy techniques by using extension methods and its methodology and application need to be further developed. Finally, this article succinctly summarises some recommendations for further research.