Comparative Lca Analysis for Replacement of Materials to Reduce Environmental Impact.

The paper presents examples of LCA application to reduce environmental impact by replacement of conventional materials in chemical, biochemical, construction and electrical industry. Examples of replacement of talc-reinforced polypropylene composite by lightweight composite, using of natural aggregates versus recycled aggregates coming from reinforce concrete demolition, replacing of carbon black with graphene in tire production, production of asphalt mixtures, change of metal contacts for perovskite/silicon (Si) tandem structure of solar cell, etc. are described showing reduction of environmental load in impact categories or carbon footprint. The full case study of LCA of analysis to replace Indium, a material extensively used as Transparent Conductive Oxide (TCO) compound for opto-electronic industry is presented. Several alternative materials for indium-tinoxide (ITO) replacement as pure zinc oxide (ZnO) or doped with aluminum (Al) either boron (B) and tin oxide (SnO2), deposited by different techniques: physical vapor deposition (PVD), chemical vapor deposition (CVD) and atomic layer deposition (ALD) were extensively tested. ReCiPe Endpoint H/A method was applied to end up life cycle analysis with single score. In case of all layers deposited by CVD and ALD techniques the main impact is related to electricity or nitrogen consumption and the impact produced by the material is of minor significance. The results show that replacement of ITO by ZnO in TCO layer deposition process is an optimal strategy to minimize environmental impact keeping required opto-electrical properties for the economic and safe manufacturing of optoelectronic components. Environmental impact of analysed TCOs strongly depends on deposition technologies; for the layers deposited by CVD and ALD techniques the main impact is related to energy or nitrogen consumption whereas for PVD to energy and material of TCO. [ABSTRACT FROM AUTHOR]