| |
|
Methyl Diethanolamine
(MDEA) |
| |
Comparison of various
parameters of MEA,DEA and MDEA are given below in TABLES I-VI : |
Camparision of Amines
TABLE I
|
| Solvent |
MEA |
DEA |
MDEA |
| Concentration% |
15 |
30 |
35-50 |
| Solvent Circulation GPM |
100 |
100 |
100 |
| Acid Gas Removal Capacity MOL/HR |
49.8 |
58.6 |
87.5 |
| Capacity Increase % (MEA BASE = 100) |
100 |
118 |
175 |
|
| |
Performance of Media
TABLE II
|
| Solvent Concentration% |
35-50 |
| Solvent Circulation GPM |
10-1600 |
| Rich MDEA Loading MOL/MOL |
0.50 |
| Lean MDEA Loading MOL/MOL |
0.01 |
| Reboiler Steam, #/GPM |
0.67-0.85 |
| Lean MDEA Temperature 0F |
130-160 |
| CO2 Slip, % CO2 Rejected
|
50 |
|
| |
|
| |
Heat of reaction with H2S and CO2
TABLE III
|
| |
| |
Heat of
reaction BTU/POUND |
| Amines |
H2S |
CO2 |
| MDEA |
450 |
577 |
| DEA |
493 |
650 |
| MEA |
650 |
820 |
|
| |
|
| |
Selectivity and Capacity
TABLE IV
|
| |
| |
Capacity |
| Amines |
Selectivity* |
Mol H2S/Mol Amine
|
Mol CO2/Mol Amine
|
| MDEA |
3.85 |
0.10 |
0.12 |
| DEA |
2.27 |
0.09 |
0.32 |
| MEA |
0.89 |
0.07 |
0.50 |
*Selectivity is defined as ratio of (mole percent
of H2S removed to mole percent of H2S in feed gas) to (mole percent
of CO2 removed to mole percent of CO2 in feed gas) |
| |
|
| |
Recommended ranges of Amines Concentration
- Rich and Lean Amines Loading
TABLE V
|
| |
| Amines |
Conc. Weight % |
Rich Loading M/M |
Lean Loading M / M
|
| MDEA |
35-55 |
0.45-0.55 |
0.004-0.01 |
| DEA |
25-30 |
0.35-0.40 |
0.05-0.07 |
| MEA |
15-20 |
0.30-0.35 |
0.10-0.15 |
|
| |
|
| |
Corrosion
TABLE VI
|
| |
| Solvent |
Corrosion Rate MPY |
30% Wt MEA
|
32 |
| 50% Wt DEA |
25 |
| 15% Wt MEA |
13 |
| 20% Wt DEA |
8 |
| 50% Wt MDEA |
3 |
|
| |
|
