Proposals for the redesign of the mouthwash production chain based on environmental performance indicators

Abstract

This study describes the results of the initial redesign process phase of the production chains of two mouthwashes, namely an alcohol-based product (‘A’) and a polyol-based product (‘B’), in order to improve their environmental performance. Initially the LCA technique estimated impacts in terms of Primary Energy Demand, Global Warming Potential, Terrestrial Acidification, Photochemical Oxidation Formation, Terrestrial Ecotoxicity, Agricultural Land Occupation and Water Depletion for the original arrangements. The main impacts of 'A' comprised the application of renewable alcohol in its composition and the use of N2 as the inerting fluid used to seal the reactors, while fossil polyol stands out as the main opportunity for improving ‘B’ manufacturing performance. Three redesign proposals were defined for Product ‘A’: renewable alcohol replacement by fossil alcohol, the use of Pressure Swing Adsorption (PSA) instead of cryogenics for N2 production and reducing the amount of this fluid in the reactors. Renewable polyol was introduced in 'B' instead of the fossil version.Although both measures were proven effective, a second round of LCA indicated that N2 content reduction combined with the PSA technology was more effective in improving the overall performance of 'A' manufacturing than the inclusion of synthetic alcohol in its formulation. The use of renewable polyol is a recommendable practice except for its performances regarding Terrestrial Ecotoxicity and Agricultural Land Occupation, comprising greater contributions compared to its former performance. The environmental consequences of those interventions were also evaluated in collective terms through the Global Environmental Indicator (GEI). For ‘A’, GEI confirmed the effectiveness of the proposed measures, which, when associated reduced the impacts originally identified in its processing by 74%, while renewable polyol was not able make ‘B’ production less environmentally aggressive.