Role of water and other H-rich additives in the catalytic combustion of 1,2-dichloroethane and trichloroethylene.
In several practical applications gas streams containing chlorinated volatile organic compounds with variable chemical nature (namely, 1,2-dichloroethane and trichloroethylene) and a significant moisture content (15000ppm) must be addressed. In this paper the control of such emissions by catalytic oxidation over Ce/Zr mixed oxides was analysed. Results in terms of activity and selectivity were compared with those obtained when other H-rich additives (1000ppm), such as hexane or toluene, were fed. High activity was found from mixed oxides featuring a suitable combination of a large population of acid sites, easily accessible oxygen species, and hydrophobic nature attributable to cerium content. The presence of additional H-rich compounds in the feed stream (water, toluene or hexane) tended to decrease the catalytic activity due to the blockage and/or competition for actives sites. However, the increased presence of hydrogen atoms in the stream notably promoted the selectivity to hydrogen chloride instead of molecular chlorine.
de Rivas
Beatriz
B
Chemical Technologies for Environmental Sustainability Group, Department of Chemical Engineering, Faculty of Science and Technology, Universidad del País Vasco/EHU, PO Box 644, E-48080 Bilbao, Spain.
López-Fonseca
Rubén
R
Gutiérrez-Ortiz
Miguel A
MA
Gutiérrez-Ortiz
José I
JI
D000397:Air Pollution / Q000032:analysis*; D002384:Catalysis; D002563:Cerium / Q000737:chemistry; D005025:Ethylene Dichlorides / Q000032:analysis*; D006586:Hexanes / Q000737:chemistry; D014050:Toluene / Q000737:chemistry; D014241:Trichloroethylene / Q000032:analysis*; D014867:Water / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry
D005025:Ethylene Dichlorides; D006586:Hexanes; D014867:Water; D014241:Trichloroethylene; D002563:Cerium; D014050:Toluene; C024565:ethylene dichloride; C030583:ceric oxide; D015040:Zirconium; C028541:zirconium oxide