混合吸附剂对吸附-间歇低温等离子体氧化甲苯的影响

Effect of mixture adsorbents on adsorption-intermittent non-thermal plasma oxidation of toluene

常温常压下,以γ-Al_2O_3小球、13X分子筛或者两者的混合物为吸附剂,采用吸附-间歇等离子体氧化系统去除模拟干燥空气中的甲苯.结果表明,仅以γ-Al_2O_3小球为吸附剂,碳平衡较高,其中CO_2产率为50%,但吸附穿透时间短,且有甲苯解吸出来.仅以13X分子筛为吸附剂,吸附穿透时间较长,放电阶段无甲苯解吸,且副产物O_3和N_2O较少,但碳平衡较低,其中CO_2产率仅41%.不同比例混合的吸附剂中,13X和γ-Al_2O_3质量比为1/2时,碳平衡最高可达到96%,其中87.7%为CO_2.最后结合吸附剂的吸附性能和放电特征分析了混合吸附剂CO_x产率较高的原因.

Using small particles of γ-Al2O3,molecular sieve 13 X,or their mixture as adsorbents,an adsorption-intermittent plasma oxidation system was employed to remove toluene from the simulated dry air under atmospheric pressure and temperature. The results showed that the carbon balance withγ-Al2O3 as the adsorbent was higher than that with 13 X. The CO2 yield was 50% with γ-Al2O3 while only 41% with 13 X. However,the breakthrough time of γ-Al2O3 adsorption was shorter than that for molecular sieve 13 X,and the amounts of byproducts O3 and N2O produced by γ-Al2O3 were higher than that produced by 13 X. Moreover,some toluene was desorbed when γ-Al2O3 was used. When a mixture of 13 X and γ-Al2O3 with mass ratio of 1 / 2was used,the carbon balance could reach 96% with 87.7% of CO2. Finally,the reason for the better COx yield of the mixed adsorbents was analyzed based on the adsorption performance and electric discharge characteristics.