A scholarly report in the journal Science Advances from researchers at the University of Kansas shows a new eco-friendly method for separating the chemicals found in common refrigerants for easier recycling at industrial scale.
“The motivation of this work is to enable separation of highly complex gaseous refrigerant mixtures,” said lead author Abby Harders, who performed the research as a KU doctoral student in the research group of co-author Mark Shiflett, Foundation Distinguished Professor of Chemical and Petroleum Engineering. “This effort has been driven by climate legislation phasing out certain hydrofluorocarbon (HFC) refrigerants.”
The paper's key innovation uses membranes — amorphous fluorinated polymers, to be specific — that efficiently isolate complex refrigerant mixtures. Other separation methods, like distillation, are less effective because of the complex composition of the mixtures. Harders said the membranes are fabricated to allow some gases to pass through while restricting others — resulting in effective purification.
To demonstrate the technology could scale to industrial viability, the team — including many associated with KU’s Wonderful Institute for Sustainable Engineering — developed a custom-coating process to create submicron coatings on the membrane’s porous supports, creating composite hollow fibers. The results show a functional prototype, proving the technology’s usefulness to firms engaged in refrigerant recovery and reuse.