Reddit reviews Unit Operations of Chemical Engineering (7th edition)(McGraw Hill Chemical Engineering Series)

> Methanol does not form an azeotrope with either ethanol or water.

The only azeotrope I mention is the one formed between ethanol and water.

>What this post says is definitely not true, and is contradictory to real chemistry. If acetone and other volatile compounds (like methanol) are distilled in the foreshots.

No it is not, it is perfectly in line with real chemistry. It is not in line with the simplified version we explain to lay people on how distillation works. Boiling point is not the only factor involved. Of course this post is also an over simplification, and is targeted at a particular audience, readers of this sub using small scale distillation equipment.

Here is an example run analysis of a sugar wash. Can you explain why isoamyl-acetate presents such a large fraction in the foreshots, when its boiling point is 142C? Or even the slightly elevated presence of furfurol, which has a boiling point of 162C?

>"Methanol removal is treated separately and requires its own process to concentrate and extract using specialized equipment."

I touched on this, it is separated using large plated columns whose sole purpose is to isolate and remove methanol. An azeotropic mixture of water/ethanol containing other components (methanol in this case) is fed above the middle of a 70+ plate column at near boiling. Steam injection at the bottom performs the distillation, while hot water is added to the top of the column and moves a methanol enriched cut to the top of the column, while the cleaned product is removed at the bottom plate as a lower proof spirit, to be run through another rectification stage to return to azeotrope. This is performed on 96% input feed which has already been through a rectifying column with the heads and tails removed. Due to the low water content of the input feed and greatly reduced heads/tails load, this column can more properly do boiling point separation combined with the water feed and using the particular properties of methanol and water. If you'd like a more technical overview of the process, I'd suggest reading "Unit Operations of Chemical Engineering".

Other methods can be employed, such as pressure swing distillation, azeotropic distillation and similarly extractive distillation, using other solvents.

Pot stills and small reflux columns cannot do any of this. There will be methanol in your foreshots, certainly. As well as being in your hearts, tails and in the backset. These are trace levels and distillation is never carried out on azeotrope boiler volumes.

Did you read the study I linked, where the recycling of tails was the primary factor in elevated methanol levels in fruit brandy?

I think I had this for a sophomore class and found it too basic to be of value. Maybe unit ops

https://www.amazon.com/Unit-Operations-Chemical-Engineering-McGraw/dp/0072848235

Transport and thermo and some applications

I got my PE last April. I recommend you get a study manual with practice problems from amazon and work your way through it chapter by chapter. Then, a month before the exam start the NCEES practice exam questions over and over again until you understand how to do each question. The NCEES questions are really close to those on the exam with a few twists and a few new ones thrown in. You should be spending 10 hrs each week for 4 month preparing for it. I recommend this series of review manuals: Chemical Engineering Reference Manual for the PE Exam, 6th ed. also Unit Operations of Chemical Engineering and Levenspiel's Reaction Engineering. Also, get yourself a copy of Crane TP410.

Edited to correct links.

Unit Operations of Chemical Engineering by McGraw Hill and Perry's Chemical Engineering Handbook have the information on calculating heat transfer coefficients for heat exchangers. Heat exchangers can require itterative calculations if you're doing the calcs by hand. It's much easier to use software like HTRI

https://www.amazon.com/Unit-Operations-Chemical-Engineering-McGraw/dp/0072848235/ref=sr_1_1?crid=SUID9EFA8VUO&keywords=unit+operations+of+chemical+engineering+7th+edition&qid=1567017287&s=gateway&sprefix=unit+operati%2Caps%2C174&sr=8-1

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Still need these, btw.