Serine (Mw 105) is to be recovered from an aqueous solution containing 30% (w/w)

Question

Serine (Mw 105) is to be recovered from an aqueous solution containing 30% (w/w) serine. In one steady state process, a fresh feed of 100 lbm/hr of this aqueous solution is mixed with a recycle stream (first recycle) and sent to a separator that removes only water selectively by a process of pervaporation. In the pervaporation unit, approximately 51.35 lbm/hr of water is removed to concentrate the solution such that the output contains approximately 9 lbm of serine for every 11 lbm of water. To facilitate crystallization, addition of methanol is performed. A fresh feed of methanol containing a non-volatile impurity is used. This impure fresh feed is mixed with a recycle stream (second recycle) of pure methanol, which brings the impurity content of the resulting stream to 1.5% (w/w). The resulting mixed stream is then combined with the output from the pervaporation unit before being sent to a crystallizer-filter unit. In this unit, pure solid crystals of serine monohydrate are recovered as primary product. The filtrate is sent to an evaporator unit that separates out only methanol as vapor: 80% of the methanol input to the evaporator is recovered as vapor. This vapor is condensed and is the basis of the second recycle that mixes with the impure methanol feed. The liquid stream from the evaporator containing unrecovered methanol and other constituents forms the basis of the first recycle stream that is mixed with the fresh feed of serine solution. It is found that 80% of the serine in the fresh feed is recovered in the primary product stream of crystals from the process. To achieve this recovery, the combined stream sent to the crystallizer filter unit has to be controlled to contain 2.5% (w/w of the impurity en answer the Draw a schematic and solve the material balances for all streams. questions below

Explanation / Answer

To made the caluclation we assume the intial input preoperator is 100 lbm/hr

in the input we have a composition of serine and water

at the end 51.35lbm /hr of water is evaparated

the intial assumpition is made for all fundamental material ballance calculations

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.