Page 322 - Petroleum and Gas Field Processing

X 2 ¼ lean glycol weight percent ¼ 98.5 (given)
VðY Y Þ¼ LðX X Þ
1
2
1
2
3
where L is the circulation (ft /h).
If we assume that 2 gal TEG/lb H 2 O are needed, then the TEG
circulation rate is found to be
L ¼ GðY 1 Y 2 Þð2Þ
98 1day 1L
¼ ð63 7Þð2 galÞ
day 24 h 60 min
gal
¼ 7:6 ðgpmÞ
min
We can find X 1 from the material balance equation:
3
ft
98 MMSCD ðY 1 Y 2 Þ¼ ðX 2 X 1 Þ
day
ft 3 7:6 gal 60 min 24 h
98ð63 7Þ¼ ð98:5 X 1 Þ
9:5 min 1h 1 day
5488 ¼ 1459:2ð98:5 X 1 Þ
3:761 ¼ 98:5 X 1
X ¼ 98:5 3:76
1
¼ 94:7
From Figure 6, we can find the theoretical number of stages: N ¼ 1.5
stages. Assuming 25% efficiency,
1:5
N act ¼ ¼ 6 stages
0:25
Assuming a spacing of 2 ft, the height H is found to be 12 ft.
The dew point of the exit sales gas can be estimated from Figure 2

and found to be equal to 10 F.

12.5 ADSORPTION: SOLID-BED DEHYDRATION

When very low dew points are required, solid-bed dehydration becomes
the logical choice. It is based on fixed-bed adsorption of water vapor by a
selected desiccant. A number of solid desiccants could be used such as
silica gel, activated alumina, or molecular sieves.
The properties of these materials are shown in Table 2. The selection
of these solids depends on economics. The most important property is the

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