Methanol distillation operation
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What is the steam rising speed inside the tower, and why is it said that the greater the reflux, the higher the steam rising speed inside the tower? I seek advice from experts
Is it true that the rising steam velocity indicates the light components?
The speed at which steam rises within the tower directly affects the mass transfer efficiency. Generally, the maximum steam rise speed in the tower should be lower than the flooding velocity; in practice, the maximum allowable speed is often set at 80% of the flooding velocity. If the speed is too high, flooding or entrainment of foam may occur, while if it is too low, leakage will happen, resulting in a significant decrease in the efficiency of the tower plates. Saying that the rising steam velocity represents the light components is not entirely correct. It also contains a recombined fraction, whose vertical distribution is in the form of an equilateral triangle, unlike that of the light fraction. So there is production from the streamline, returning to the top of the tower.
The condensate reflux at the top of the tower consists mainly of lighter components. The more reflux there is, the further it flows downward in the tower, where it is reheated and vaporized by the rising steam, resulting in an increased steam flow rate and faster velocity in the upper part of the distillation tower. This creates a vicious cycle; therefore, it is important to control the steam flow rate.
Simply put, the greater the backflow, the more vapor is condensed
I’m looking to recover the fusel oils obtained through distillation of methanol; if anyone knows someone who can help, please point me in the right direction – I’ll be extremely grateful.
The solution at the bottom of the tower generates steam after heat exchange, and this steam undergoes mass exchange with the reflux liquid between the tower trays. If the rising steam volume is too large, flooding or foam entrainment is likely to occur; therefore, the speed of the rising steam should not be too high. It should be that the greater the steam rise rate inside the tower, the greater the reflux required as well. Personal opinion! ! !
Simply put, the greater the reflux, the higher the concentration of light components in the distillation section, and the more steam is generated