3.3 Absorption and desorption performance of DBU-2EG
The experiment on H2S solubility is carried out in a
three-necked round bottom flask at 100 kPa, 25℃. The saturated
solubility of H2S in DBU-2EG was measured by the
weighing method.37 Results show that the solubility of
H2S can reach 2.64 mol/mol (DBU), which is highest than
the value of other absorbents reported in the literature (Table 2). To
illustrate the property of the generation DBU-2EG for
H2S absorption, the DBU-2EG-4H2S
complexes were heated to 60 ℃ under atmospheric pressure for 40 min. It
is found that DBU-2EG-4H2S can completely convert back
into DBU-2EG, which has an unchanged H2S solubility of
about 2.64 mol/mol (DBU) compared with the fresh DBU-2EG (Figure S4).
Under the same conditions, the absorption solubility of the DBU-EG
multimer absorbent for H2S is 1.25 mol/mol (DBU), which
is approximately 47% that of the DBU-2EG multimer absorbent. This
result is consistent with the analysis in section 3.1.2 formation
mechanism and H2S absorption mechanism of DBU/EG
multimer absorbents.
TABLE 2 Comparison of the solubility of
H2S in different absorbents .