Question

One thousand kilograms per hour of a mixture of benzene and toluene that contains 50% by mass are seperated by distallation into two fractions.

The mass flow of benzene in the top stream is 450kg benzne/hour, and toluene in the bottom stream is 475 kg toulene/hour.

Write the material balance on benzene and toluene to calculate the unknown components in the output stream.

Answer 1

50 kg benzene/hour and 25 kg toluene/hour

Step-by-step explanation:

According to Lavoisier's law, the mass can't be created either destroyed, thus, the material in the input must be equal to the material in the output + the material formed if there's a reaction + the accumulation in the reactor.

Thus, for bezene:

minput = mtop + mbottom

If 50% of the mass is composed by each substance:

0.5*1000 = 450 + mbottom

500 = 450 + mbottom

mbottom = 50 kg benzene/hour

For toluene:

minput = mtop + mbottom

0.5*1000 = mtop + 475

mtop = 500 -475

mtop = 25 kg toluene/hour