Electrochemical method for wet removal of phosphine

Abstract

The removal of phosphine (PH3) was studied with an electrochemical approach using a Ti/SnO2 anode. The effects of the current density, O2 content, gas flow rate, temperature, and type of electrolyte on the PH3 removal were investigated. The liquid phase reaction products were detected by ion chromatography. It was observed that PH3 was effectively removed in the electrochemical reactor and phosphate (PO43−) existed in solution after reaction. Increasing current density, oxygen content and reaction temperature can enhance the removal of PH3. 0ver 85% PH3 was removed with an operation condition of current density of 53.05 mA/dm2, 65°C, 4.6 vol % O2 and gas flow rate of 200 mL/min in 0.1 mol/L Na2SO4 aqueous solution. Chosen Na2SO4 as electrolyte, removal efficiency remained stability and it would be conducive to the recovery of phosphate (PO43‐). The gas flow rate influence is remarkably clear in the reactor where it was evident that the most efficient gas flow rate toward a 90% PH3 removal was reached at 50 mL/min. Electrochemical oxidation will be a potential method for the PH3 removal because of its low cost, long duration removal efficiency and the valuable hydrogen byproduct produced. © 2015 American Institute of Chemical Engineers Environ Prog, 34: 1640–1646, 2015