@article{10902/29174,
year = {2023},
month = {9},
url = {https://hdl.handle.net/10902/29174},
abstract = {Difluoromethane (R-32) is a hydrofluorocarbon (HFC) that has been massively used over the last 30 years in refrigeration and air conditioning as a primary component of azeotropic or close boiling refrigerant mixtures. Despite environmental directives commanded to drastically reduce the use of HFCs, R-32 has excellent thermodynamic properties and moderate GWP, thus its recovery from depleted mixtures collected from end-of-life equipment is sought to synthesize alternative low-GWP refrigerant blends. Membrane separation using composite polymer/ionic liquid membranes based on poly-ether-block-amide have shown potential to separate R-32 from other fluorinated hydrocarbons, yet the development of this type of composite membranes still remains at laboratory scale. In this work, a spray coating technique was successfully applied to create defect-free thin selective layers of neat Pebax®1657, Pebax®1657/40 wt% [C2C1im][BF4] and Pebax®1657/40 wt% [C2C1im][SCN] coated on porous PVDF substrates. This methodology was transferred from the lab-scale tests (12.6 cm2) to a custom pilot set-up (300 cm2). The pilot results confirmed the superior performance and stability of [C2C1im][SCN]-based membranes, which allowed the recovery of up to 64.3% and 67.1% R-32 from the refrigerant mixtures R-410A (69.8 mol % R-32 and 30.2 mol % R-125) and R-454B (82.1 mol % R-32 and 17.9 mol % R-1234yf) at 6 bar, increasing the R-32 permeate concentration up to 89.6 and 95.9 mol %, respectively. These results highlight the need to expand the knowledge of this type of gas separation membranes towards thinner and defect-free selective dense layers with the purpose of approaching their real applications.},
organization = {This research is supported by Project KET4F-Gas – SOE2/P1/P0823, Project PID2019-105827RB-I00 funded by MCIN/AEI/10.1039/501100011033 (Spain), and project LIFE4F-Gases (LIFE20CCM/ES/001748) co-funded by the European Union LIFE programme. F.P. acknowledges the post-doctoral fellowship (IJC2020-043134-I, ‘Juan de la Cierva Incorporación’) funded by the Spanish Ministry of Science and Innovation MCIN/AEI/10.13039/501100011033 and the European Union NextGenerationEU/PRTR. S. V. G. acknowledges the pre-doctoral fellowship FPI PRE2020-093568, funded by the Spanish Ministry of Science and Innovation MCIN/AEI/10.13039/501100011033 and by “ESF Investing in your future”.},
publisher = {Elsevier},
publisher = {Separation and Purification Technology, 2023, 320, 124115},
title = {Polymer/ionic liquid pilot scale membrane prototype for the recovery of difluoromethane (R-32) from refrigerant mixtures},
author = {Pardo Pardo, Fernando and Gutiérrez Hernández, Sergio Valentín and Rodríguez San Miguel, Paula and Zarca Lago, Gabriel and Urtiaga Mendia, Ana María},
}