Usually reboiler duty vs feed stage forms a U shape with a clearly defined minimum, but for this case it gives an abnormal shape. ls this normal, if yes using your experience which stage will you use as a feed stage. Find attached the paramedic study for your reference.
Kind regards,
distillation
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thubelihle
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distillation
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Re: distillation
Quoting Prof. Ross Taylor:
Unclear what the issue is here; there is a minimum on the plot. The point at stage 5 on the plot failed so that one i bogus. It failed because the product mole fractions cannot be reached. Use a different spec to get those feed stages to work (bottoms flow rate).
In any case use the McCabe-Thiele diagram to determine optimum feed stage.
The pressure profile looks wrong. The condenser is at a much higher pressure than the top stage of the column. There is no way the vapor could enter the condenser. Normally pressure increases going down. The bottoms pressure is higher than the top but stage 2 is much lower than the condenser. This is wrong.