Can we use air instead of nitrogen in initial start up? (All catalysts are oxidize)

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Amirsadat
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Can we use air instead of nitrogen in initial start up? (All catalysts are oxidize)

Post by Amirsadat »

We plan to start the plant, and now all catalysts are oxidize.
Can we use air instead of N2 circulation for initial warm up?
After that we can purge the air by steam before gas in.
Satyajit
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Re: Can we use air instead of nitrogen in initial start up? (All catalysts are oxidize)

Post by Satyajit »

Never use air as some catalysts are pre-reduced and pyrophoric at high temperature. Most important is to purge the system to avoid explosive mixture before the feed is introduced.
LeoMirazu
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Re: Can we use air instead of nitrogen in initial start up? (All catalysts are oxidize)

Post by LeoMirazu »

Dear, you can use air to warm up the primary and secondary reformer. Never use them to warm up HTS and LTS, y this case you can use CH4 instead of N2 but never Air
vpattabathula
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Re: Can we use air instead of nitrogen in initial start up? (All catalysts are oxidize)

Post by vpattabathula »

Yes, we have been using air during startup mainly through primary & secondary reformers until we get to the above steam saturation point and then we introduce process steam to reformers. At this stage, we protect HTS catalyst by having a blind at its inlet valve.

We do the same to cool down reformers by using air on a planned shutdown.
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