KrBr~*准分子灯直接光解一甲胺气体

Direct Photolysis of Methylamine Gas by KrBr~* Excilamp

研究了正弦电源驱动的207 nm KrBr*准分子灯光解气相中的一甲胺(MA).考察了降解的影响因素(气体流速、初始浓度、输入功率),测定了灯的输入功率和辐射光谱.为了评价光解过程,对去除效率、能率、碳平衡和CO2的选择性这4个参数进行了研究.结果表明,去除率随着灯的输入功率升高、气体流速的降低以及气体初始浓度的升高而升高.能率与一甲胺初始浓度呈正相关性,输入功率为65.1 W时能率最高.输入功率升高,气体流速下降,碳平衡和CO2选择性都略有升高.当灯的输入功率为79.8 W,气体流速9.0 m3·h-1,初始浓度为2 897 mg·m-3,一甲胺去除率为56.8%,能率为185.6g·(kW·h)-1,相应的碳平衡和CO2选择性为16.8%和10.3%.最后,利用气质联用仪测定了一甲胺降解的产物,结合一甲胺的吸收光谱,推测了一甲胺的光解机制.

A study on methylamine （MA） photo-dissociation in gas phase has been carried out using UV radiation from a 207 nm KrBr＊ exeilamp driven by a sinusoidal electronic control gear. The influence factors including gas flow rate, initial concentration and input power of removal efficiency were investigated. The radiant power and spectrum of the lamp were measured. Several parameters were investigated including removal efficiency, energy yield, carbon balance and CO2 selectivity in order to comprehensively evaluate the photo-dissociation process. It was shown that the removal efficiency increased with enhanced input power, decreased gas flow rate and increased MA initial concentration. Energy yield had positive pertinence with MA initial concentration, and it would obtain optimal value at 65.1 W. Carbon balance and CO2 selectivity showed slighter enhancement when lamp power increased and gas flow rate declined. The removal efficiency of 56.8% was achieved at a lamp power of 79. 8 W, a gas flow rate of 9.0 m3 .h-1 and an MA initial concentration of 2 897 mg. m -3 Under the above mentioned experimental conditions, energy yield reached 185.6 g. （ kW· h） -1 , and carbon balance and CO2 selectivity were 16.8% and 10.3% , respectively. At last, secondary products formed were analyzed by gas chromatography-mass spectrometry and the photo-degradation mechanism of MA was suggested on the basis of UV-vis absorption spectrum.