Fractional Distillation PDF Download

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1922 edition. Excerpt: ...the more volatile component than the liquid with which it mixes, thereby increasing the proportion of volatile component on the top plate. Continuing, as the composition of the liquid on the top plate increases in the more volatile component, the effect will be felt on the plate below, and after the distillate from the condenser has been returned to the column for a considerable length of time, the effect will be that all of the plates in the upper portion of the column will contain substantially nothing but the more volatile component. When this condition has been reached, if the valve leading from the condenser to the receiver for distillate is then opened, the first portion of vapor which comes over will be that liquid which has collected on the plates in the upper portion of the column and will, therefore, be practically pure component. When the contents of the column have distilled over in this manner, there will be a sudden break in the composition of the distillate and when this break occurs, the fraction is shifted and a small intermediate fraction is then recovered in a separate distillate receiving tank. If this method of complete reflux of the distillate were not practiced, the amount of intermediate fraction between any two pure fractions would be very greatly increased. In the same way, when the benzene has been nearly all distilled over, it is possible to obtain a sharp cut between the benzene and the toluene fractions by refluxing completley for a certain length of time. There will be, of course, a small intermediate fraction consisting of a mixture of benzene and toluene and this intermediate fraction must be returned and mixed with the next charge which is put into the kettle and redistilled. The net capacity of any...