ECO-DESIGN FOR END-OF-LIFE PHASE OF FLAME RETARDANT TEXTILES

Production, consumption, and disposal of textile products have substantial adverse impacts on the environment, especially textiles with flame retardant (FR) finishes. Unfortunately, information on the exposure of FR from textile products to environmental pathways is scarce. Research works on FR textiles have been mostly focused on ways to provide environmentally friendly synthesis and production phases of FR textile products. However, the end-of-life phase of the FR textiles seems neglected and needs great attention when the product’s life cycle is concerned. The end-of-life phase of FR textile products is considered as a hurdle in current sustainable disposals (landfill and incineration), though today, technologies for solid waste management are ever-improving. Indeed, landfill and energy valorization through incineration are considered as suitable pathways for textile wastes, including technical textile wastes. However, the end-of-life of FR textile products creates issues, such as in landfilling, there is a huge chance of FR species or substance leaching to the environment. Similarly, FR species decrease energy yield in the incineration process due to incomplete combustion and emits toxic fumes. It is essential to find different ways to assess the most optimum methods or eco-designs for the disposal of textile products by energy valorization through gasification. Therefore an eco-design was proposed with optimized disposals for the FR textiles. Eco-design comprises the degradation and elimination of a permanent/durable FR substance from the textiles, especially cellulosic textiles prior to their disposals. Thermal valorization was achieved by gasification instead of incineration, to explore the ability of FRs to gasify after the degradation and elimination of the FR species. Durable FR species, for instance, n-methylol dimethyl phosphonopropionamide (MDPA) is one of the most effective organophosphorus FRs for cellulosic fabrics, used in combination with trimethylol melamine (TMM) to obtain durable and improved FR properties. The degradation and elimination of an organophosphorus FR (MDPA) on cellulosic fabric, was studied using an advanced oxidation process (AOP) based on Fenton’s reaction. The effect of varying concentrations of Fenton’s reagents (H2O2 and Fe2+ in aqueous medium) on the degradation of the MDPA was studied. The degradation of MDPA in aqueous media was monitored by measuring chemical oxygen demand (COD) of the reaction mixture over time. The mechanical properties of the cellulosic fabric after Fenton’s reaction were unaltered in both warp and weft directions. The flammability test and thermogravimetric results (TGA, DTG and PCFC) confirmed the degradation of MDPA FR from the fabric. FR species being degraded and eliminated from the cotton textiles, energy valorization by gasification was carried out for increased energetic yield due to better combustion and potential syngas composition outcomes during the gasification. The gasification results supported the eco-design by showing increased combustion properties of the FR textiles after the degradation and elimination of the FR species. For the sustainability validation of the proposed eco-design, a life cycle assessment (LCA) was performed to analyze the environmental impacts of eco-design for the end-of-life phase of FR textile products. LCA is one of the prominent assessment methods to perform the general assessment of products or services. The thermogravimetric and pyrolysis combustion results confirm that there is a higher heat release after Fenton’s reaction degradation. The heat release rate of the FR cotton textiles increased by 51% after the degradation of the FR species, and this makes the degraded FR cotton interesting for energy valorization. The energy valorization by gasification results supported the eco-design by showing increased combustion properties of the FR textiles after the degradation and elimination of the FR species. Lastly, the LCA results showed reduced impact values in most of the impact categories studied, especially in global warming potential (GWP), air acidification (AA) and in other prominent categories in favor of degradation and elimination of FR species from the textiles and being gasified.