Environmental and energetic effects of cleaner production scenarios on the Sodium Lauryl Ether Sulfate production chain

Abstract

Abstract Sodium Lauryl Ether Sulfate is an important surfactant used by the Specialty Chemical Industry. However, little quantitative information regarding its environmental impacts in a systemic perspective is available. Therefore, this study assessed the environmental performance of 1.0 ton of Sodium Lauryl Ether Sulfate containing 3 mol of ethylene oxide (SLES 3EO), by means of a ‘cradle-to-gate’ Life Cycle Assessment. Environmental impacts were quantified in terms of Global Warming Potential and Primary Energy Demand (PED). Carbon Footprint was also estimated according to ISO 14067 guidelines. The Global Warming indicator was calculated as 1.87 t CO2eq/t for the baseline scenario, while PED was estimated as 71.7 GJ/t. Based on the main sources of impact, four individual alternatives aiming at environmental performance improvement were proposed, based on the Resource Efficient and Cleaner Production philosophy: S1) production using palm kernel oil from Brazil; S2) production from synthetic lauryl alcohol; S3) generation of thermal energy from biomass; S4) SLES 3EO synthesis using ethylene oxide obtained from sugarcane. Possible synergies deriving from the combinations of these propositions were also assessed, considering seven additional scenarios (S5 – S11). It was observed that lauryl alcohol performance was very influential and decisive for the results. Moreover, thermal energy from biomass was beneficial in terms of Global Warming, while increasing the renewable fraction of the PED indicator. On the other hand, ethylene oxide production from sugarcane ethanol was not an advantageous alternative, due to high fuel and thermal energy demands throughout its production chain. The Carbon Footprint assessment according to the ISO 14067 standard indicates a beneficial change in the impact profiles between the scenarios presenting renewable source assets participating in their life cycle, with a strong reduction in relation to the results obtained by applying the IPCC approach. Synergy among cleaner production propositions was observed and highly influenced by the amount of biomass incorporated to SLES 3EO life cycle. This can be considered an innovative approach regarding the Brazilian context. As a pioneer initiative, it is expected that the outcomes from this investigation would contribute to future initiatives investigating detergent formulation from an environmental perspective.