Original Article:
Aqueous carbonation of MgSO4 with (NH4)2CO3 for CO2 sequestration
Chenhui Deng, et al.
Greenhouse Gases: Science and Technology, 2019, 9(2): 209-225.
10.1002/ghg.1840
Carbon dioxide capture, utilization, and storage technology (CCS/CCUS) is widely recognized as an important option for CO2 emission reduction. Studies have shown that mineral carbonation is a potential method for sequestering CO2, in which various minerals (especially silicon Alkaline earth elements in minerals) react with CO2 and form thermodynamically stable carbonates.
In this work, the carbonization of magnesium sulfate-rich solutions, one of the key steps in the indirect mineral carbonization of blast furnace slag, was studied in detail using ammonium carbonate ((NH4)2SO4) as a recyclable reagent. A schematic diagram of the mineral carbonation process is shown in the figure. According to the systematic study of the feeding mode and process parameters in the carbonation process of MgSO4 and ammonium carbonate solution in this paper, it is proposed that the chemical reactions involved in the process include:
(1) When the mole ratio of (NH4)2CO3 to MgSO4 was 2:1 and the concentration of magnesium sulfate was higher than 0.4 mol L-1, the carbonated products contain ammonium magnesium carbonate, and the ammonia should be recovered by selective thermal decomposition. MgCO3 · 3H2O (s) + 2NH4+ (aq) + CO3 2-(aq) + H2O (l) → MgCO3 · (NH4)2CO3 · 4H2O (s)
(2) When the mole ratio decreased to 1.5:1, only nesquehonite appears with high crystallinity and uniform size. 4MgCO3 · 3H2O (s) → Mg4(CO3)3(OH)2 · 3H2O (s) + 8H2O (l) + CO2(g)
Chemicals Related in the Paper:
| Catalog Number | Product Name | Structure | CAS Number | Price |
|---|---|---|---|---|
| ACM506876 | Ammonium carbonate |  |
506-87-6 | Price |
