Question

An equimolar mixture Of methane and propane 's discharged from a compressor at 5,500 kPa and 900 ^oC at the rate of 1.4 kg

a) If the velocity in the discharge line is not to exceed 30 m s-i, as an engineer, calculate what is the minimum diameter of the discharge line?
b) What will be the impact towards society, health, safety, and/or environment if the engineer used diameter Of discharge line less than the minimum diameter found in part (a)?
c) What will be the impact towards society, health, safety, and/or environment if the engineer used diameter Of discharge line more than the minimum diameter found in part

Answer 1

Let's assume methane as component 1 and methane as component 2.

Then,

T := 363.15-K 1 : 0.012 Tel := 190.6. P:-5500-kPa yi :-0.5 Zoi := 0.286 Pel :=45.99. bar Y2:= 1 Zc2 0.276 Pe2:= 42.48-bar 6)2 := 0.152 2-369.g.K

The elevated pressure here requires use of either an equation of state or the Lee/Kesler correlation with pseudocritical parameters. Let's choose the later one, then

Ppc := yi.pci + y2.Pe2

=>
Tpc = 280.2 K
and
Ppe 44.235 bar

Also,

lpr :=- Tpr= 1.296 P r :=- Ppr = 1.243 pc pc

By interpolation in Tables E.3 and E.4: ZO: 0.8010 Z1: 0.1100

For the molar mass of the mixture we have:

molwt- (y1.16.043 +y244.097) gm mol

molwt-30.07 mol

So, the minimum diameter is 2.964 cm.