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Process Circuit Analysis 137

Table 3.5.4 Repeated Variables and Equations - Methanol-Synthesis
Process
Line Repeated Variables Repeated
Number V R Equations
RR

2 Y2,i - Y2,s - Y2,4 - Y2,s - Y2.6 - rr\2 0
3 Ys,3 - Ys,4 - Ys.s - m 3 X y 3 1 = 1
4 Y4.1 - Y4,2 - Y4,3 - Y4,4 - Y4,5 - Y4,6 - I Y4,i = 1
m 4
7 y?,i - y?,3 - y?,4 - y?,5 - yr.e - ni/ lY7,i=1

Table 3.5.5 Degrees of Freedom Calculation - Methanol-Synthesis
Process
Process Unit Unit Unit
Variables Equations
Vu Ru

Mixer 11 7
Converter 13 9
Condenser-Separator 15 11
Splitter 18 12
Total 57 39

Line Repeated Repeated
Number Variables Equations
VR RR

2 6 0
3 4 1
4 7 1
7 6 1
Total 23 3

Process Degrees of Freedom

F P = (Vu - V R) - (Ru - RR ) = (57 - 23) - (39 - 3) = 34 - 36 = - 2

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