Operation of the benzene column in the extraction system
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What are the key operating points for a benzene tower? How much benzene should be extracted by stripping? If the temperature difference is high when benzene is extracted through the side line, how should it be controlled? What are the components of the benzene tower feed, and what are their proportions?
Optimization is carried out based on the design of the tower, with main considerations including parameters such as temperature, pressure, and reflux ratio
Could you please specify these parameters and indicate what their values are in practice?
Our intermittent output is sometimes 0.4 tons
The feed components of benzene tower are: non-aromatics 0.02%, benzene around 92%, toluene around 8%
What are the flow ratio percentages for benzene tower feed, overhead benzene extraction, benzene side-stream withdrawal, and benzene reflux? What is an appropriate pressure level for the benzene tower?
The operation of the benzene tower is primarily aimed at controlling the quality of benzene; in addition, it is necessary to regulate the amount of benzene at the bottom of the tower. It is very difficult to handle situations where benzene enters the downstream unit, that is, the toluene tower. The amount of benzene extracted from the top of the tower is determined based on the required purity level of benzene. 95% of this extracted benzene is pure benzene, with the remainder being non-aromatic compounds. Only by removing these non-aromatic compounds from the top of the tower can it be prevented from ending up in the side streams. If the temperature difference for controlling the benzene in the side stream is too high, reduce the extraction of benzene from the side stream (this is what is done when using temperature difference control for the side stream)
A higher temperature difference can increase the reflux rate and reduce the pumping volume; specific adjustments are needed in each case. For example, if the level of the liquid in the tank is low, it is not possible to increase the reflux rate – only the pumping volume can be reduced