CHBE 221 Lecture 6: CHBE 221, Lecture 6.pdf

A purification system with recycle isused to recover the solvent DMF from a waste gas containing 55 mol% DMF. The product is to have only 5 mol % DMF. The purificationunit can remove three-fourths of the DMF from the combined feed tothe unit. Calculate the mol fraction of DMF entering thepurification unit and the recycle ratio (recycle ratio = moles inrecycle/moles in feed).

A purification system with recycle is used to recover the solvent DMF from a waste gas containing 60% DMF in air. The product is to have only 10% DMF. Calculate the recycle fraction (the ratio of the molar flowrate of the recycle stream to the molar flowrate of the pure DMF stream leaving the purification unit) assuming that the purification unit can remove two thirds of the DMF in the combined feed to the unit.

24. Most of the municipal solid wastes end up by: