Life Cycle Impact Assessment of Solution Combustion Synthesis of Titanium Dioxide Nanoparticles and Its Comparison with More Conventional Strategies

Abstract

This paper represents the first attempt to quantitatively and reliably assess the environmental sustainability of solution combustion synthesis (SCS) with respect to other soft chemistry strategies, which are more conventionally employed in the preparation of engineered oxide nanomaterials, namely hydrolytic and non-hydrolytic sol-gel syntheses (i. e., HSGS and NHSGS). Indeed, although SCS is well known to rely on significant reduction in the energy as well as time required for the obtainment of the desired nanocrystals, its quantitative environmental assessment and a detailed comparison with other existing synthetic pathways represents an absolute novelty of high scientific desirability in order to pursue a more sustainable development in the inorganic chemistry as well as materials science research fields. TiO 2 nanoparticles were selected as the material of choice, for the production of which three slightly modified literature procedures were experimentally reproduced and environmentally evaluated by the application of the comprehensive life cycle assessment (LCA) methodology. Particularly, SCS was compared from an environmental perspective with sol-gel approaches performed both in water and in benzyl alcohol. The results of the present study were also framed among those recently obtained in a systematic study assessing seven further chemical, physical, and biological routes for the synthesis of TiO 2 nanoparticles, comprising also flame spray pyrolysis (typically used in industrial productions), highlighting and quantifying the excellent environmental performances of SCS.

Environmental Sustainability of π‐Electron Donor‐Based Deep Eutectic Solvents for Toluene Absorption: A Life‐Cycle Perspective

“…The system boundary includes the upstream processes of obtaining absorbent such as the production of the precursors (HBA and HBD) and DESs, and the toluene absorption process of DESs, as shown in Figure 1. It is reported that the construction, installation and the end of life stages have little impact on the overall life cycle for a chemical plant, thus only the impacts of the production and application stages are considered [29] . For the application of absorbing toluene, similar to the reference [28] the reuse of the absorbent is not included for the cradle‐to‐gate study in this work, because of the recovery and regeneration requiring additional resources.…”

Systematic Life Cycle Environmental Impact Comparison of Alternative Synthetic Strategies for Ti3C2Tx MXene

“…In addition to the necessary input materials and energy contributions, the inventory also accounted for the equipment used as well as the waste generated during synthesis and workup procedures. For the electric energy consumptions, the power of the equipment employed, and their time of usage were generally considered (if not otherwise specified), similarly to other works devoted to the assessment of lab-scale procedures. , …”

“…For the electric energy consumptions, the power of the equipment employed, and their time of usage were generally considered (if not otherwise specified), similarly to other works devoted to the assessment of lab-scale procedures. 27,45 The contribution of the transport of materials and equipment was also considered by assuming 100 km as a reasonable average distance. The road freight transportation by diesel EURO 6 46 lorries with a capacity of 16−32 t was considered.…”

“…Being understood the pioneering character of the first LCA study of Ti 3 C 2 T x, the huge number of available MXene synthetic pathways, makes it fundamental to objectively quantify and, above all, compare the environmental impacts associated with both well-established synthetic methods and newly proposed ones, similarly to what performed with further nanomaterials. − …”

Innovative Bioplasticizers from Residual Cynara cardunculus L. Biomass-Derived Levulinic Acid and Their Environmental Impact Assessment by LCA Methodology

“…The life cycle impact assessment (LCIA) phase was conducted by employing the global scale-oriented method ReCiPe2016 both at midpoint and endpoint levels, with a hierarchist (H) perspective and average weighting set (A) . This method is one of the most widely accepted and applied global methods, − comprising a high number of impact categories …”