An exergy based approach to resource accounting for factories. (10th May 2016)

• Record Type: Journal Article
• Authors: Khattak, Sanober Hassan; Greenough, Richard; Korolija, Ivan; Brown, Neil
• Is Part Of: Journal of cleaner production. Volume 121(2016:May)
• Page Start: 99
• Page End: 108
• Publication Date: 2016-05-10
• Subjects: Sustainable manufacturing -- Resource accounting -- Exergy analysis -- Resource efficiency -- Energy efficiency -- Buildings energy management; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2015.12.029
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: Resource accounting is widely practiced to identify opportunities for improving the sustainability of industrial systems. This paper presents a conceptual method for resource accounting in factories that is based on the fundamentals of thermodynamics. The approach uses exergy analysis and treats the factory as an integrated energy system comprising a building, its technical building services and manufacturing processes. The method is illustrated with a case study of an automotive cylinder head manufacturing line in which the resource efficiency of this part of the factory is analysed for different energy system options relating to heating ventilation and air conditioning. Firstly, the baseline is compared with the use of a solar photovoltaic array to generate electricity, and then a heat recovery unit is considered. Finally, both of these options are used together, and here it was found that the non-renewable exergy supply and exergy destruction are reduced by 51.6% and 49.2% respectively. Also, it was found that a conventional energy analysis would overestimate the resource savings from reducing the hot water supplied to the heating system, since energy analysis cannot account for energy quality. Since exergy analysis accounts for both energy quality and quantity it produces a different result. The scientific value of this paper is that it presents an exergy-based approach for factory resource accounting, which is illustrated through application to a real factory. The exergy-based approach is shown to be a valuable complement to energy analysis, which could lead to a more resource efficient system design than one based on energy analysis alone. Highlights: A novel exergy-based approach to resource accounting in factories is presented. The approach is explained using a case study of a cylinder head machining line. An energy system re-design is presented with half the baseline resource consumption. The tendency of energy analysis to overestimate resource efficiency is explained. The paper explains how exergy analysis can drive resource efficiency improvements.