Troy B. Scoggins

Moisture effects on purifier/chemical filter materials

A method was developed to measure hydrocarbons to 1 part-per-trillion (ppt) concentration levels with a gas chromatograph and flame ionization detector (GC/FID).1 This method was used to measure purifier siloxane removal efficiencies from air under dry and humid conditions. Several media types were examined: activated alumina (AA), activated carbon (AC), bead-shaped activated carbon (BAC), a proprietary inorganic material (PIM) and a zeolite (ZEO). Under dry conditions, all five materials removed the siloxane challenge to below 1 ppt. The AC material had a removal efficiency of 286 ppt under humid conditions. The AA, BAC, PIM and ZEO removed the siloxane challenge to below 1 ppt under humid conditions. After media saturation was reached, the materials were regenerated and siloxane removal efficiencies were reexamined. Under humid conditions only the AA, PIM and ZEO materials were regenerable to below 1 ppt efficiency levels