2 replies to this topic

[trevortnt]

Hi my exam is so close and I have been unsuccessful in self teaching myself about ternary diagrams. I feel I can read them confidently but need some much needed help if I'm going to have a chance of passing my exam. Here is a question which if i could do might help me to understand them.

A 150kg/hr stream ethlene glycol and water (30wt% ethlene glycol and 70% water) is treated with 50kg/hr furfuraldehyde to extract the ethlene glycol in a series of mixers adn settlers in a counter-current system. Graph is attached to this thread.

a) determine the composition at psuedo-mixture point (not sure were this is)?

what is the psuedo mixture point and what other points should i be aware of? Graph is attached to this thread.

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•  graph.jpg   83.22KB   33 downloads

[siretb]

I am not sure about what you know, because this is a very basic problem. Please return to the books.

The pseudo mixture point is, at least the way I understand it , the point that represents the overall composition.
You start from a point on the left triangle line (H20-Ethyleneglyclo line. and draw a line towards the extractant (furfural).
Since you have 150 kilos of mixture and 50 kilos of solvent, the mixture is at a distance of (50/(50+150)) that is one fourth away from the H20-Ethylene glycol line, and towards the furfural point.

This mix will separate into two phases, the to x's at each extremity of the coordination line. You will get fractions in proportion to the actual distances from the mix point to the two x's, in this case about 60% of the water rich phase and 40% of the furfural rich line.

Attached Files

•  diagram.bmp   7.43MB   39 downloads

[trevortnt]

hi thanks so much for your help but i think its too late for me now. my exam is already today