Study of the enrichment of NF 3 waste gas using zeolite and polymeric membranes

Abstract

A zeolite membrane and polymer membranes were prepared for the enrichment of NF 3 waste gas. NF 3 is a strong greenhouse gas with a 100 year global warming potential (GWP) of >16,600, and is mostly used in the plasma enhanced chemical vapor deposition (PECVD) process as an etching and cleaning gas. First, dense polymer films using polysulfone, polyimide, AF-1600®, AF-2400®, PDMS (polymethylsiloxane), PTMSP (poly (1-trimethylsilyl-1-propyne)), and PTMSDPA (poly[1-phenyl-2-[p-(trimethylsilyl)phenyl]acetylene]) were prepared, and their N 2 /NF 3 separation performance was studied. High N 2 /NF 3 ideal selectivity was obtained from the polyimide and polysulfone films, but these modules were not attractive for the NF 3 enrichment process because of their low N 2 /NF 3 mixture gas selectivity. SAPO-34 membranes were then prepared and applied for the NF 3 enrichment process. This membrane exhibited promising separation performance (>200 N 2 /NF 3 selectivity, >6.7 × 10 −8 N 2 mol/m 2 /s/Pa) for the NF 3 enrichment process. However, in order to deal with a high waste stream volume, it was necessary to greatly increase the membrane area. Potential zeolite membrane frameworks for NF 3 enrichment have been proposed through membrane-based system design. © 2019