Exergy analysis of construction material manufacturing processes and assessment of their improvement potentials

This study presents the application of exergy analysis in assessing how effectively resources are utilised in construction material manufacturing. The role of exergy is discussed from several key perspectives such as quality, energy conservation and process improvement potentials. Both primary and secondary processes (recycling) of nine major non–renewable construction materials (steel, aluminium, copper, cement, concrete, ceramic, glass, polypropylene and polyvinylchloride (PVC)) have been evaluated in this study. The outlined theoretical exergy efficiency approach assesses the improvement potentials of the present manufacturing processes. The large difference between theoretical and industrial exergy demand suggests that exergy resources are utilised very inefficiently in current technologies. The study reveals that more than 55% of exergy is being lost in current technologies even though a significant amount of waste heat is recovered in different segments of the case study processes. Thus, attention is required to reduce the specific exergy losses through improved process design and introduction of new technology.