水分条件下碳黑氧化气体排放特性的实验研究

Experimental study on gas emission characteristics of carbon black oxidation under water condition

基于柴油机颗粒捕集器(DPF)再生时的颗粒氧化过程,采用固定床反应器研究水蒸气条件下不同温度(495~565℃)、水浓度(0~9%)、氧浓度(5%~21%)及催化剂对均匀堆积碳黑颗粒层氧化气体排放特性的影响,通过气体分析仪测试排放气体获得碳黑氧化过程的气体排放特性.实验结果表明:温度升高、氧浓度增加与加入催化剂均会促进碳黑氧化,且催化剂CeO_(2)或Pt/Al_(2)O_(3)可使得CO接近零排放.水蒸气加入会使二氧化碳CO_(2)及CO排放量降低,碳黑氧化效率下降,水蒸气的这种抑制作用在高氧浓度时更为明显.当水浓度由0%增加至9%,气体排放量和氧化效率先下降后上升,3%时抑制效果最强,最终CO_(2)排放有所增加.此外,碳黑氧化排放的CO_(2)/CO比值随温度升高而下降,氧浓度对该比值影响较小,而水浓度升高该比值逐渐增加.

Based on the particle oxidation process during the regeneration of Diesel Particulate Filter(DPF),the gas emission under different temperatures(495~565℃),water concentrations(0~9%),oxygen concentrations(5%~21%)and catalysts on the oxidation process of uniformly stacked carbon black particle layer were studied in a fixed bed reactor.Gas emissions were measured using a gas analyzer to obtain the emission characteristics of carbon black oxidation.The experimental results showed that increasing temperature,oxygen concentration and adding catalysts promoted the oxidation of carbon black,and CeO_(2)or Pt/Al_(2)O_(3)catalysts reduced CO near to zero.However,the addition of water vapor decreased the emissions of CO_(2)and CO,as well as the oxidation efficiency.This inhibition effect was more pronounced at higher oxygen concentrations.When the water concentration increased from 0%to 9%,the gas emission and oxidation efficiency first decreased,then increased,with the strongest effect at 3%.Ultimately,the emission of CO_(2)increased.In addition,the CO_(2)/CO ratio of carbon black oxidation emission decreased with an increase in temperature,with little effect by oxygen concentration.This ratio gradually increased with water concentration.