Page 324 - Petroleum and Gas Field Processing

entering the bed from the top and the upper zone becomes saturated first.
The second zone is the mass transfer zone (MTZ) and is being loaded. The
third zone is still not used and active. The different saturation progress
and representation of different zones is shown in Figure 8. While the bed
is in operation, the outlet concentration has very low water concentration
(C s ) and the MTZ moves downward. At a certain point, the outlet water
content rises to the point that is equivalent to the initial wet gas content
(C 0 ) as if bed is not present. Thus, the beginning of this period is called the
breakthrough period ( B ). This situation is shown in Figure 9.
The operation of the process is controlled by opening valve (O) and
closing valve (C), which are shown in Figure 9. After the bed has been
used and loaded with water, then it is regenerated by hot gas (say 6 h, as
heating time H ) and then cooled by switching to cold gas (say for 2 h, C ).
The approximate temperature profile for inlet gas temperature during
heating and cooling of the bed (T i ) to desorb water, and then to cool the
bed to prepare it for next cycle and the outlet gas temperature (T 0 ) in the
same period are shown in Figure 10.

Figure 8 Mode operation.

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