Vapor phase deethanizer
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Is your vapor degasification tower running? If not, can the carbon dioxide content in propylene be kept within acceptable levels?
The C2 content in the gas-phase feedstock is primarily controlled by the catalytic absorption and stabilization unit; if the C2 level in the catalytically liquefied gas is kept very low, it may not be necessary to use an ethane removal tower, but this results in higher energy consumption for the catalytic process. So it depends on the actual operating conditions of the catalyst and the gas stream; there are units that do not have an ethane stripping tower. But sometimes, when it is necessary to remove CO, H2O, and CO2 from the top of the deethanizer, it must be turned on; otherwise, it will increase the load on the refining system of the polypropylene plant. This also depends on the factory’s overall considerations.
Generally, it is determined based on the composition of the raw materials whether to operate an ethane tower; if the ethane content is below 0.5%, there is no need to operate it at all.
This 0.5% of carbon dioxide will end up in the propylene, affecting its purity
This definitely has to be turned on; otherwise, how can the propylene meet the standards? :P
Catalytic absorption stabilization – combined gas fraction optimization allows tower 2 to be omitted. The key lies in the catalytic absorption-desorption process.
It must be turned on; if not, it fails the test. Specifically, it depends on the ethane content in the raw materials
Catalytic absorption offers low stability and is not reliable; it’s better to use an ethane tower instead
This post was last edited by Refiner on 2016-12-15 at 14:50. We also think it’s safer to keep it running; the energy consumption doesn’t increase much – it’s mainly the electricity used by the top reflux pump, the consumption of cooling water for the tower top, and the use of hot water in the bottom reboiler
It mainly depends on the C2 content in the raw materials, as well as the operational stability of absorption
The operation of the absorption and stabilization tower is crucial