## 3 WEEE and ELV Management and Circular Economy
### New Technologies for the Recovery and Separation of HFCs  
Despite the benefits of reclaiming refrigerants at short term, at long term the switch to alternatives with lower GWP must be made. However, some of the high GWP blends currently in use are still valuable. The constituents of the most used high GWP blends,such as R-410A (GWP 2088) and R-404A (GWP 3922), have high value compounds that can be used as single component refrigerants or in low GWP blends.  
The blend R-410A (GWP 2088) is one of the main refrigerants used in refrigeration and air conditioning systems. However, due to its high GWP, it is being substituted by alternatives with lower GWP. One of those alternatives is R-32 (GWP 677), one of the components of the blend together with R-125 (GWP 3170), mostly in low-capacity systems. This refrigerant was present in approximately 37% of all split systems in 2019 and is expected to exceed 80% by 2023 [55]. In Japan, a complete shift towards R-32 (GWP 677) occurred in produced residential split air conditioners, starting from 2014 [56]. In some air conditioning sectors, blends of R-32 (GWP 677) with other HFCs and HFOs, such as R-454B (GWP 466) and R-452B (GWP 676), are being promoted as alternatives to R-410A (GWP 2 088).  
Therefore, there are undeniable advantages in separating value-added F-gases from blends recovered from EoL equipment and further recycling and reusing them, either as single component refrigerants or in blends. However, this approach has received little encouragement and no developed technologies are currently available. Since most refrigerants are azeotropic or near-azeotropic mixtures, conventional processes, such as distillation, are not efficient or feasible. For example, R-410A (GWP 2088) is a near-azeotropic system of R-32 (GWP 677) and R-125 (GWP 3170), with an azeotropic composition at 91 mol% R-32 (GWP 677).  
The research on technologies based on environmentally benign materials that efficiently capture, separate, and recycle F-gases is vital to develop sustainable processes to reduce the environmental impact of refrigerants based on F-gases. The implementation of innovative approaches based on separation processes is vital to the functioning of a sustainable market under circular economy principles. However, few projects have been dedicated to exploring the separation of HFCs from HFC blends. Recently, under the scope of the KET4F-Gas project [57], two technologies, currently in the patent process, have been developed and prototypes have been constructed for the efficient recovery of value-added HFCs, with purity up to 99%, from high-GWP refrigerant blends contained in EoL equipment, for reutilization purposes in novel environmentally friendly low-GWP blends. These technologies are easy to apply in a waste management facility due to the small space required, and due to their modularity and scalability. Moreover, these systems require low maintenance and have a long lifetime [58; 59]. One of the technologies is based on adsorption processes, in which one of the components of the mixture is preferentially adsorbed into a porous material while the remaining leaves the adsorption column, including the regeneration of the adsorption column to recover the adsorbed gas [60]. The other technology is based on the separation by a membrane, in which one compound of the mixture is preferentially permeated through highly selective thin films due to differences in the size of the gas molecules and to gas-membrane interactions [61].  
This example shows that innovation in the management of F-gases recovered from EoL equipment is possible and is essential to the goals of reducing the contribution of these gases to climate change. Actions, such as investment in the search for new separation technologies, need to be performed in the management of F-gases since most are recovered and destroyed at the end-of-life of the equipment, representing a loss of value-added compounds.