(2) Multi-Unit, Multi-Reaction Process (50 pts)

The diagram below shows a process to produce a product E from A and B. In addition to the

information labeled on the diagram, it is known that the recycle stream to Reactor P (stream 6)

has the molar ratio of A to B equal to 1:9. You are asked to find (1) the split ratio of the recycle

to purge flow and (2) the overall fractional conversion of A. Follow the general protocol to:

organize the information (label the diagram, write aux. equations, write goals) (10 pts)

analyze the problem (clearly state a solution strategy based on DOF analysis without

solving the entire process, use the DOF tables below if needed) (30 pts)

solve for the goals (pick a basis or convert units if necessary, write relevant material

balances and solve). Suggestion: do the algebra until you finish everything else (10 pts)

nĄ.4

a)

b)

c)

n₁.1

B.1

P1: A+B → 2C

P2: A + 2B → 3D

Reactor P

n₁.6

ńB.6

ń₁.2

nc.2

np. 2

Q: 2C + D → E

Reactor Q

n₁,3

ńD. 3

ŻE.3

R: D+E 4B

Reactor R

= 18 lbmol/s

Splitter

n₁,5 = 4 lbmol/s

np. 5

ŻE.5

np.4

nE.4/nDOF

IstrV

IsysV

Variables

SF

SC

AUX

AUX

MBS

DOF

If I had solved

(unit/system):

the we would get

a new DOF for:

IstrV

IsysV

Variables

SF

SC

Specified syst. vars.

MBS

NEW DOF →

P

Q

(which unit/system)

After solving the above unit/system,

Spltr

R

has DOF = 0 and can be solved to determine

After solving the above unit/system,

Strategy to solve for the goals (you may not need all lines below):

Process

has updated DOF = 0 and can be solved to determine

I/O

(which variables)

has updated DOF = 0 and can be solved to determine