Re: Heating Considerations and Stainless Steel
> When you say to just keep the heat on and control the reflux, doyou mean to just leave the heat and let it get as hot as it likes,
then strip the water
> and others out with the tower? Don't worry about what is coming upinto the
> column as long as alcohol is all that comes out?Yes is the answer to your question, but with an explaination. Your
boiler will not be under pressure (if everything is working right) so
the highest it will ever get to is the temperature of boiling water.
The amount of heat that you input depends on the capacity of your
column to process the extra vapor. A 1 inch column can handle much
less heat and vapor volume than a 2 inch column.
If you can control the reflux rate with your condensor, then the
column will reach equalibrium after a brief period after it reaches
temperature. That means that all of the different components present
in the boiling wash will stack themselves up at different levels
inside of the column. Your column head temperature will actually be
lower than that of ethanol at first.
The lower temperature components are the foreshots. You would start
drawing off product slowly until the head temperature reaches 78.1
(c) then you can separate the heads from the middle run and tails. If
you keep careful control of the draw off rate, then the head
temperature will stay close to that of ethanol because the column
will able to maintain its ballance. If you start drawing off too
fast, then the head temperatures will start to rise higher than
ideal. After the product is done, you can choose to end the run or
continue distilling until you salvage the rest of the ethanol out of
the boiler. If you bring the head temperature up to a few degrees
below the temperature of boiling water, then you can add that part to
another wash and redistill that portion later on.