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US 4,059,677 AGranted
Catalytic oxidation of C.sub.2 -C.sub.4 halogenated hydrocarbons
AssigneePPG Industries, Inc.
InventorsEdward J. Sare, Jerome M. Lavanish
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AssigneePPG Industries, Inc.
InventorsEdward J. Sare, Jerome M. Lavanish
Estimating the term…
C.sub.2 -C.sub.4 halogenated, e.g., chlorinated and brominated, hydrocarbons, such as vinyl chloride, present in a gas stream are removed therefrom, e.g., incinerated, by contacting the gas stream with an oxygen-containing gas in the presence of metal oxide catalyst system consisting essentially of the oxides of manganese and cobalt at relatively low temperatures, e.g., 100.degree. C. Commonly, the halogenated hydrocarbon is present in the gas stream to be treated in small amounts, e.g., less than 0.05 weight percent. The temperature of treatment can vary, e.g., from 20.degree. C. to 500.degree. C., and can be adjusted within said range depending on the relative humidity of the gas stream treated to maintain catalytic activity. Preferably, treatment occurs under conditions of low relative humidity, e.g., less than 5 percent, and the metal oxides of the catalyst system are hydrated.
A method for treating a C.sub.2 -C.sub.4 halogenated hydrocarbon containing gas stream, said halogenated hydrocarbon being selected from the group consisting of chlorinated and brominated hydrocarbons, which comprises contacting the halogenated hydrocarbon with an oxidizing amount of oxygen-containing gas in the presence of metal oxide catalyst system, the metal oxide catalyst content of which consists essentially of a mixture of hydrated manganese oxide and cobalt oxide, the weight ratio of manganese oxide to cobalt oxide being from 19:1 to 1:19, at temperatures within the range of from 20.degree. C., to 500.degree. C., for a time sufficient to reduce the halogenated hydrocarbon content of the gas stream, said temperature being such as to inhibit water-induced loss of catalyst activity.
A method for treating C.sub.2 -chlorinated hydrocarbon containing air stream, which comprises contacting the chlorinated hydrocarbon with an oxidizing amount of oxygen at temperatures within the range of from 20.degree. C. to 500.degree. C. in the presence of metal oxide catalyst system, the metal oxide catalyst content of which consists essentially of a mixture of hydrated manganese oxide and cobalt oxide, the weight ratio of manganese oxide to cobalt oxide being from 10:1 to 1:10, for a time sufficient to reduce the C.sub.2 -chlorinated hydrocarbon content of the air stream, said temperature being such as to inhibit water-induced loss of catalyst activity.
A method for reducing the vinyl chloride content of a vinyl chloride-containing gas stream which comprises contacting the vinyl chloride of the gas stream with an oxidizing amount of oxygen-containing gas in the presence of metal oxide catalyst system, the metal oxide catalyst content of which consists essentially of a mixture of hydrated manganese oxide and cobalt oxide, the weight ratio of manganese oxide to cobalt oxide being from 5:1 to 1:5 at temperatures within the range of from 20.degree. C. to 300.degree. C., for a time sufficient to reduce the vinyl chloride content of the gas stream, said temperature being such as to inhibit water induced loss of catalyst activity.
Dependencies are inferred from the claim text.