Photo-dissociation of dimethylamine by KrBr* excilamp

Abstract

A study of dimethylamine photo-dissociation in the gas phase has been conducted using UV radiation delivered from a KrBr* excilamp, driven by a sinusoidal electronic control gear with maximum emission at wavelength of 207nm. The electrical input power and radiant power of the lamp were measured to determine their effects on the degradation. The influence of flow velocity and initial concentration of dimethylamine were also examined. In order to evaluate the photo-dissociation process comprehensively, several parameters were investigated, including removal efficiency, energy yield, carbon balance and CO2 selectivity. It is shown that the removal efficiency increases with enhanced input power and decreased gas flow rate. A high removal efficiency of 68% is achieved for lamp power 102W and flow velocity 15m3h−1. The optimum dimethylamine initial concentration is around 3520mgm−3, for which the energy yield reaches up to 442gkWh−1 when the input power is 65W. In addition, two chain compounds (1,3-bis-dimethylamino-2-propanol; 3-penten-2-one, 4-amino) and three ring organic matters (1-azetidinecarboxaldehyde, 2,2,4,4-tetramethyl; N-m-tolyl-succinamic acid; p-acetoacetanisidide), were identified by GC–MS as secondary products, in order to demonstrate the pathways of the dimethylamine degradation.