Use of mercury catalysts
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The catalyst currently in use makes it difficult to control the reaction temperature. A plant with a capacity of 120,000 tons starts to struggle when operated at a load of over 30%. Could there be any problems if too many converters are in use and all of them are operating at low load? Discuss and exchange views on issues such as the operating temperature of mercury catalysts, their usage time, and the rate at which the reaction zone shifts downward. The primary manifold has 24% acetylene, and the secondary one has some temperature issues exceeding the limits.
In the initial 1,000 hours of operation with the new catalyst, it is necessary to run it at a low load, with the temperature kept below 160°C; otherwise, overheating may cause the catalyst to sublimate, and the explosion-proof membranes in the converter’s hot water system will burst frequently. After 1,000 hours, the load is gradually increased; the downward shift of the reaction zone is related to your production level – the higher the load, the faster the catalyst is consumed, and thus the faster the downward shift. At present, for low-mercury catalysts, considering switching to an inverse catalyst at around 25 is advisable; otherwise, the second-stage catalyst will be used up quickly and the parameters will exceed the limits.
With lower system pressure, the temperature can be lower.
Well, flipping it over too quickly may lead to high overall catalyst consumption; we try to use it as little as possible. How is the use of low-mercury catalysts where you are?
Turning to catalysts, there are advantages as well as disadvantages. The advantage is that the catalysts mix evenly, which increases the overall time required for consumption. The downside is increased labor costs, as well as a higher probability of catalyst fragmentation, which inadvertently leads to greater catalyst consumption. We have been driving for over a year; some old catalyst was added before the current catalyst was installed, so after around 10,000 hours of use, its activity declined to such an extent that the acetylene level exceeded 30% of the specified threshold. In recent days, the issue related to the catalyst has started to reappear.