3. A continuous fractionating column is to be designed to separate 30000 1b/h of a mixture of
40% benzene and 60% toluene into an overhead product containing 97% benzene and a
bottom product containing 98% toluene. These percentages are by weight. A reflux ratio of
3.5 moles to 1 mole of product is to be used. The molal latent heats of benzene and toluene
are 7360 and 7960 cal/gmol, respectively. If the feed is liquid and at its boiling point.
【題組】(2)The molal latent heats of steam is 939 cal/gmol and used for heating, how much steam is
required per hour for the above cases, neglecting heat losses and assuming the reflux is a
saturated liquid? (7%)