Catalytic Destruction of Dichloromethane Using Perovskite-Type Oxide Catalysts

Abstract

Dichloromethane (DCM, also known as methylene chloride [CH 2 Cl 2 ]) is often present in industrial waste gas and is a valuable chemical product in the chemical industry.This study addresses the oxidation of airstreams that contain CH 2 Cl 2 by catalytic oxidation in a tubular fixed-bed reactor over perovskite-type oxide catalysts. This work also considers how the concentration of influent CH 2 Cl 2 (C 0 ϭ 500 -1000 ppm), the space velocity (GHSV ϭ 5000 -48,000 1/hr), the relative humidity (RH ϭ 10 -70%) and the concentration of oxygen (O 2 ϭ 5-21%) influence the operational stability and capacity for the removal of CH 2 Cl 2 .The surface area of lanthanum (La)-cobalt (Co) composite catalyst was the greatest of the five perovskite-type catalysts prepared in various composites of La, strontium, and Co metal oxides. Approximately 99.5% CH 2 Cl 2 reduction was achieved by the catalytic oxidation over LaCoO 3 -based perovskite catalyst at 600°C. Furthermore, the effect of the initial concentration and reaction temperature on the removal of CH 2 Cl 2 in the gaseous phase was also monitored. This study also provides information that a higher humidity corresponds to a lower conversion.Carbon dioxide and hydrogen chloride were the two main products of the oxidation process at a relative humidity of 70%.

Perovskites as Substitutes of Noble Metals for Heterogeneous Catalysis: Dream or Reality

“…These byproducts are formed in much lower proportion over LaMnO 3 . Manganites appear to be more selective to CO 2 and more stable than cobaltites …”

“…Manganites appear to be more selective to CO 2 and more stable than cobaltites. 454 Destruction of C2-CHC was also investigated by Sinquin et al over LaMnO 3 . 455 As for C1-CHC, water plays a significant role and H 2 O/O 2 mixtures are recommended for destruction of these compounds.…”

Incinerating Volatile Organic Compounds with Ferrospinel Catalyst MnFe2O4: An Example with Isopropyl Alcohol

“…9 They have found that the metallic components of catalysts, such as zinc (Zn), titanium (Ti), copper (Cu), iron (Fe), chromium (Cr), vanadium (V), Cerium (Ce), manganese (Mn), nickel (Ni), and cobalt (Co), can all be used in a spinel structure. Therefore, theoretically, the metallic oxide manufactured from FP should exhibit some catalytic characteristics.…”

Highly Selective Catalytic Dechlorination of Dichloromethane to Chloromethane over Al−Ti Mixed Oxide Catalysts

“…These are also recognized as chlorinated volatile organic compounds (CVOCs), which are very harmful to the environment and human body, thus its exposure should be suppressed. The oxidative decomposition of CVOCs by reacting them with dioxygen can convert CVOCs to harmless substances such as carbon dioxide, in which a number of efficient catalysts have been studied for the catalytic oxidation of CVOCs, including zeolites, [8][9][10] perovskites, [11][12][13][14] noble metals [15][16][17][18][19] and metal oxides. [20][21][22][23][24][25][26][27][28][29] The complete oxidation of CVOCs to CO 2 would be efficient approach to solve the environmental problems of CVOCs, but another potential way to convert the CVOCs into value-added intermediates could be considered.…”