Page 62 - Gas Purification 5E

52 Gus PuriJication

Table 2-2
Comparative Operating Data for MEA and DEA Systems

I GasPlant -4 B B C D
Feed gas composition
Mole 9 HIS 2.1 7.1 7.1 2.4 16.5
Mole % CO, 0.7 5.9 5.9 4.9 8.0
Solvent
(‘3 active reagent in
water solutionl 18%, 15% 249, 22.5% 27.5%
MEA ME.4 SNPA-DEA DEA SNPA-DEA
Solvent circulation
Moles amine per mole
acid gas 1.8 2.5 1.3 1.5 1 .o
Gallons solvent per
mole acid gas 74 123 68 84 44
Reboiler steam
Ib stedgal solvent 1 .o 1.2 1.5 1.2 1 .o
lb steadmole acid gas 74 148 72 101 4
I Source: Beddome (1969)

Table 2-3
Comparison of Typical Operating Data of MEA-DEG and DGA Systems

ME A-DEG DGA

Gas volume, MMscfd 121.2 121.3
Solution rate, gpm 7 14 556
Reboiler steam, lbh 50,700 4QlOO
Solution loading, scf acid gadgal 4.0 5.5
HIS in treated gas! graid100 scf 0.25 0.25
C02 in treated gas, Mol8 0.01 0.01
Source: Holder (1966)

DGA has proven to be very effective for purifying large volumes of low pressure
(-100-200 psig) associated gas in Saudi Arabia. DGA is particularly useful for such applica-
tions because it can operate at high ambient temperatures and can produce sweet gas (44 ,gain
H2S/100 scf) at moderate pressures. Information on commercial applications of the Fluor
Econamine process has been presented by Dingman (1977), Mason and Griffith (1969), Husal
and van de Venne (1981). Bucklin (1982), and Weber and McClure (1981). Comparison of
the process with systems using MEA solutions indicates some capital and operating cost sav-
ings, as well as improved operation at relatively low pressures (Huval and van de Venne,
1981). An additional adwntage is partial removal of COS by the DGA solution. Furthermore,
steam distillation can be used to recover a substantial portion of DGA from the degradation