Regarding the second solvent for aromatic extraction?

I’m not sure if the second solvent you mentioned refers to the solvent that is added before the rich stream coming out of the bottom of the extraction tower enters the stripping tower Generally speaking, the role of the second solvent is as follows: 1. It can reduce the relative volatility of the light hydrocarbon components in the rich stream, thereby making it easier for the light components to flash in the feed section, while the solvent and heavier components are less likely to flash (a stripping tower consists only of a feed section and a stripping section). 2. It reduces the likelihood of foaming within the stripping tower, thereby minimizing the risk of column flooding. It is beneficial for stable operation, especially when there are fluctuations in the extraction tower. 3. For the extraction units of some processes, increasing the amount of the second solvent can raise the steam generation rate of the water stripping tower. How to use the second solvent? 1. An excessive amount of the second solvent increases the liquid load on the stripping tower and the recovery tower, raises the resistance inside the towers, increases energy consumption, and can severely lead to tower flooding. 2. Generally, the amount of the second solvent is 10% of the flow rate of the rich solvent at the bottom of the extraction tower, and it shall not exceed the designed feed rate of the stripping tower. 3. During low-temperature seasons, an appropriate amount of secondary solvent must be provided to prevent freezing.

Thank you for your explanation; I understand a lot now. Please keep guiding me in the future. :lol

Good, understood:lol :lol :lol