Methods and systems for purifying styrene feedstock comprising use of low palladium catalyst
OwnerJames T. Merrillinventor
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Abstract
Apparatus, methods and systems useful for removing phenylacetylene from crude styrene feedstock are disclosed. Generally the processes and systems comprise the catalytic reduction of phenylacetylene to produce styrene via injection of a phenylacetylene reducing agent, such as hydrogen. A phenylacetylene reduction catalyst preferred Wherein comprises palladium on a calcium aluminate carrier, wherein the catalyst comprises less than 0.3 weight percent palladium.
Claims20
A system for decreasing the level of a contaminant in a crude styrene feedstock, the system comprising:
- a) a crude styrene supply comprising an initial level of contaminant X, a crude styrene input stream, and a crude styrene output stream, wherein said crude styrene input stream is arranged to receive crude styrene from an ethylbenzene dehydrogenation unit, wherein said crude styrene is produced by dehydrogenation of ethylbenzene in said dehydrogenation unit;
- b) a hydrogen source arranged to inject a first portion of hydrogen into the crude styrene output stream to produce stream B;
- c) a first catalyst bed arranged to receive stream B, wherein the first catalyst bed comprises a first catalyst bed output stream, wherein the first catalyst bed comprises a first catalyst having from about 0.01 to less than 0.3 weight percent palladium, and wherein said first catalyst bed output stream comprises a level of contaminant X less then said initial level.
The system of claim 19 wherein said contaminant X is phenylacetylene, and wherein said level of phenylacetlyene of said second catalyst bed output stream is less than 10 ppm.
A method for decreasing the level of a contaminant in a crude styrene feedstock, the method comprising the steps of:
- a) admixing a portion of a first reducing agent together with a first portion of crude styrene to produce a stream A, wherein said crude styrene comprises an initial level of a contaminant X;
- b) contacting stream A with a first catalyst bed comprising a first catalyst comprising from about 0.01 to less than 0.3 weight percent palladium to produce stream B, wherein stream B comprises a level of contaminant X less than the initial level of contaminant X.
Dependencies are inferred from the claim text.