Carbon dioxide sequestration by direct aqueous mineral carbonation
Carbon dioxide sequestration by an ex-situ, direct aqueous mineral carbonation process has been investigated over the past two years. This process was conceived to minimize the steps in the conversion of gaseous CO2 to a stable solid. This meant combining two separate reactions, mineral dissolution and carbonate precipitation, into a single unit operation. It was recognized that the conditions favorable for one of these reactions could be detrimental to the other. However, the benefits for a combined aqueous process, in process efficiency and ultimately economics, justified the investigation. The process utilizes a slurry of water, dissolved CO2, and a magnesium silicate mineral, such as olivine [forsterite end member (Mg2SiO4)], or serpentine [Mg3Si2O5(OH)4]. These minerals were selected as the reactants of choice for two reasons: (1) significant abundance in nature; and (2) high molar ratio of the alkaline earth oxides (CaO, MgO) within the minerals. Because it is the alkaline earth oxide that combines with CO2 to form the solid carbonate, those minerals with the highest ratio of these oxides are most favored. Optimum results have been achieved using heat pretreated serpentine feed material, sodium bicarbonate and sodium chloride additions to the solution, and high partial pressure of CO2 (PCO2). Specific conditions include: 155?C; PCO2=185 atm; 15% solids. Under these conditions, 78% conversion of the silicate to the carbonate was achieved in 30 minutes. Future studies are intended to investigate various mineral pretreatment options, the carbonation solution characteristics, alternative reactants, scale-up to a continuous process, geochemical modeling, and process economics.
- Research Organization:
- Albany Research Center (ARC), Albany, OR (United States)
- Sponsoring Organization:
- USDOE - Office of Fossil Energy (FE)
- OSTI ID:
- 897123
- Report Number(s):
- DOE/ARC-2001-028; R&D Project: AE-FY-01-01; TRN: US200704%%542
- Resource Relation:
- Conference: 25th International Technical Conference on Coal Utilization & Fuel Systems, Clearwater, FL, Mar. 5-8, 2001
- Country of Publication:
- United States
- Language:
- English
Similar Records
Research status on the sequestration of carbon dioxide by direct aqueous mineral carbonation
Carbon dioxide sequestration by direct mineral carbonation with carbonic acid
Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
42 ENGINEERING
58 GEOSCIENCES
ABUNDANCE
ACID CARBONATES
CARBON DIOXIDE
CARBONATES
DISSOLUTION
ECONOMICS
EFFICIENCY
FUEL SYSTEMS
MAGNESIUM SILICATES
OLIVINE
OXIDES
PARTIAL PRESSURE
PRECIPITATION
SERPENTINE
SILICATES
SODIUM
SODIUM CHLORIDES
carbon dioxide
sequestration
aqueous mineral carbonation