chemical engineering 1 The figure below shows a desalination circuit with two RO

Question

chemical engineering 1

The figure below shows a desalination circuit with two RO units. There are five streams, whose flowrates in kg/h are labelled as A, B, E. The mass fraction of salt in stream xi. Unknown values are shown as You may assume the system is operating at steady state with no reactions 0.18 A 100 kg/h xD 0.003 0.035 0.001 3 Question Completion Sta If you also know that the concentration of salt in stream Bis xB 0.1, then determine the flowrate in kg/h of stream D. Enter your answer rounded off to one decimal place and do not include units. f you believe that no answer is possible for this question, then type "Not Possible" instead of a number in the answer space.

Explanation / Answer

From overall Mass balance:

A = C+D+E

and

Around 2 nd column:

B= C+D

Around I st column

A= B+C

Step-1:

100 = B+E

==> E=100-B

xAA =xBB + xEE

0.035 x 100= 0.1B + 0.001 X(100-B)

3.5 = 0.1B +0.1-0.001B

B= 3.4/ (0.099)

= 34.34 kg/h

and E= 100 -34.34 == 65.66 kg/h

STEP-2:

B=C+D

C= 34.34 -D

xBB = xCC+xDD

0.1 x 34.34 = 0.18 x(34.34-D) +0.003 x D

(0.18-0.003 ) D =0.08 x34.34

D= 15.5 kg/h

C= 34.34 -15.5 = 18.82 kg/h

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

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