CBEN 408 Quiz #2
Name (1 point): ___________________________________
February 22, 2016
1. (4 points) What are two (2) functions of the inlet slug catcher at the front end of a gas
processing plant?
2. (2 points) Convert 20 MMscfd to normal conditions (i.e., Nm³/day). Remember there is
also a change in the standard temperature.
3. (3 points) You’ve added ethylene glycol (C2H6O2) to suppress the formation of hydrates
by 20°F. What must be the mass fraction of glycol in the produced water phase?
Solution
1. Protect plant from large, sudden liquid influxes
Do initial separation of gas, oil, & water
2. Remember that the “standard” temperature is 60°F & the “normal” temperature is 32°F
(0°C):
3
3


m   32  459.67 °R 
6 ft
6
3
 20 10
 0.3048  
  0.538 10 Nm /day
day  
ft   60  459.67 °R 

3. The molecular weight of ethylene glycol is approximately 62 (212 + 212 + 6). Using
the Hammerschmidt equation (with value as mass fraction):
X EG 
 t  F   Mi
2062  0.347

 t  F   Mi  2335  20 62  2335
If you use the Nielsen and Bucklin equation (as mole fraction water):
  T F° 
 20 
xw  exp 
  exp 
  0.8570

129.6

129.6




Now converting to mass fraction glycol:
X EG 
1  0.8570 62
xEG MEG

 0.365
xw Mw  xEG MEG 0.8570 18.015   1  0.8570 62 