Distillation column simulation
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In the design of a rectifying tower for the recovery of propylene, how is the appropriate reflux ratio determined based on the relationship between the reflux ratio and the number of trays? I wasn’t able to understand this from the tutorials. Does the tutorial say that one needs to calculate the second derivative? I hope everyone here can help solve this!
It can’t be that bad. This system is rather special, and the selection of tower pressure is crucial. The propylene-water system exhibits a dead zone in the high-concentration region (due to near-azeotropic properties), so careful consideration is advised.
First, simulate the minimum reflux ratio using a simplified method, and then use an empirical value for the reflux ratio, taking it to be approximately 1.05 to 1.2 times the minimum reflux ratio
Thank you; I also came across mentions of this situation while searching through literature. I have the following questions: 1. What factors cause the concentration balance zone and the reflux ratio? Pressure drop? (I don’t have enough knowledge of basic chemical engineering; I hope experts can help answer this.)
Thank you; I also came across mentions of this situation while searching through literature. I have the following questions: 1. What factors cause the concentration balance zone and the reflux ratio? Pressure drop? (I don’t have enough knowledge of basic chemical engineering; I hope experts can help answer this.)
The constant concentration region is primarily determined by the vapor-liquid equilibrium state at a certain pressure; at least at 1 atm, a constant concentration region exists for propylene-water mixtures with a propylene content higher than 98.5 wt %. You can refer to solvent manuals for the Txy values. Changing the pressure can alter the range of this constant-concentration zone, or even eliminate it.