Page 319 - Petroleum and Gas Field Processing

In the glycol regenerator, the glycol temperature is normally raised up

to between 370 F and 390 F. This results in a lean glycol concen-
tration of about 98.5–98.9%. A higher temperature will cause degradation
of the glycol. To achieve higher glycol concentrations, stripping gas may
be used.

12.4.4 Process Design

The procedure for determining the absorber column diameter and height
along with solved example for a case study are presented below.
1. Column diameter. The column diameter can be calculated using
the Souder–Brown correlation:
1=2

l v
U max ¼ C SB ð3Þ
v
where U max is the maximum gas superficial velocity (ft/h), C SB is
the Souder–Brown coefficient (ft/h) (assume a value 660), l is
3
3
the glycol density (lb/ft ), and v is the gas density (lb/ft ).
The cross-section area of the column can be calculated as
V
A ¼ ð4Þ
U max
where V is the gas flow rate at operating conditions.
nZRT
V ¼ ð5Þ
P
The compressibility factor Z can be calculated from the
corresponding state method as

B r P r
Z ¼ 1 þ ð6Þ
T r

B r ¼ B þ wB 0
0:422

B ¼ 0:083
1:6
T r
0:172
0
B ¼ 0:139
4:2
T r
P
P r ¼ ðreduced pressure of natural gas)
P c
T
T r ¼ (reduced temperature of natural gas)
T c

Copyright 2003 by Marcel Dekker, Inc. All Rights Reserved.