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US 4,908,191 AGranted
Removing arsine from gaseous streams
AssigneeEthyl Corporation
InventorsSteven I. Boldish, Irfan A. Toor
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AssigneeEthyl Corporation
InventorsSteven I. Boldish, Irfan A. Toor
Estimating the term…
A method and apparatus are described for removing arsine from a gaseous stream such as the gaseous effluent stream from an MOCVD operation in which arsine is employed as an arsenic source. The arsine is burned in the gas phase in the presence of oxygen (air) to form arsenic oxide and a gaseous effluent stream in which all or part of the arsenic oxide is entrained. The arsenic oxide is removed from this stream by washing the same with an aqueous stream thereby forming an aqueous solution of arsenic oxide. At least a portion of this aqueous solution is recirculated to the aqueous spray so that a progressively enriched aqueous solution of arsenic oxide is formed. Periodically an insoluble arsenic containing compound is precipitated from the solution before it becomes saturated with arsenic oxide. Thus, arsine is eliminated from gaseous streams and converted into harmless forms which can be readily handled and disposed of without harm to the environment. At the same time water requirements in the system are kept at a minimum and waste of this resource is reduced.
A method for removing arsine from a gaseous effluent stream which comprises:
In a process in which a gaseous stream containing arsine is subjected to thermal decomposition and in which a gaseous effluent stream containing residual quantities of arsine is formed, the improvement pursuant to which the residual quantities of arsine are removed from such effluent stream and the arsenic content thereof is transformed into a disposable solid form, said improvement comprising:
A system for removing arsine from a gaseous arsine-containing stream which comprises:
Dependencies are inferred from the claim text.