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 .