Life cycle assessment (LCA) combined with EMergy evaluation for a better understanding of the environmental aspects associated with a crystal glass supply chain

Abstract

Life Cycle Assessment (LCA) has gained wider acceptance as a quantitative environmental performance tool, based on mass and energy balances. This paper applies the LCA method in a combined form with Emergy, which is a holistic and thermodynamic tool for the physical evaluation of environmental resources and services. A crystal glass production has been assessed as a case study. According with LCA method, the system was analysed from "cradle to gate". Data elaborated refer to 1 kg of crystal glass packed (functional unit). Results of life cycle inventory and impact assessment showed the highest contribution of the manufacturing phase to the total environmental impact, with evidence of CO2, NOx, SO2, and heavy metals emissions and some acid wastewater releases. Emergy results have been useful for carrying out a more reliable evaluation of the non-renewable resources involved, in terms of solar energy needed for generating 1 kg of crystal glass (sej/kg). Also with emergy analysis, the manufacturing phase highlighted the highest resources exploitation, due to water and natural gas uses. The combined use of emergy and LCA contributes important information useful for the comprehension of the crystal glass system organization and its level of environmental pressure, which could be reduced. Moreover, the integration may provide a base for a future development of the emergy evaluation within an LCA framework. © 2009 WIT Press.