【Q&A Question 053】June 12, 2016
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【Q&A Question 053】What is the purpose of adding ammonia to the hydrogenation catalyst at the start-up on June 12, 2016? The answer key will be available after responding; scoring is based on addressing the key points. The catalyst after sulfidation has high activity, and the addition of ammonia can appropriately suppress its activity.
Ammonia injection can deactivate the catalyst; ammonia molecules can adsorb in the micropores of the catalyst and remain there for a period of time. Prevents the oil product from coming into contact with certain catalysts and reacting temporarily
It acts as a passivator, suppressing the catalyst’s activity.
Suppress catalyst activity to prevent excessive activity of the catalyst right after vulcanization, which could lead to overheating
Since fresh catalysts exhibit very high activity in the short term at startup, this high activity can lead to unnecessary side reactions, thereby reducing the catalyst’s lifespan. To suppress this high activity, ammonia is injected for purification after the catalyst has been sulfided.
Catalytic hydrogenation generally produces products and water, with no other by-products formed (except for side reactions), thus exhibiting excellent atom economy. Green chemistry is the prevailing trend in scientific research and production today, and our country has oriented the approval of major scientific research projects in this direction.
Passivation catalyst to prevent a significant excessive rise in catalyst activity at high temperatures.