EXERGETIC AND ENVIRONMENTAL ASSESSMENT OF MINERAL CARBONATION PROCESSES IN BRAZIL
ARCE, G.L.A.F.1; NETO, T.G.S.1; Perrella, J.A.B.2; Carvalho Jr., J.A.2; LUNA, C.M.R.2
1 LCP/INPE - Combustion and Propulsion Associated Laboratory, National Institute for Space Research.; 2 UNESP - Univ. Estadual Paulista, Faculty of Engineering at Guaratinguetá, Department of Energy.
doi:10.20906/CPS/COB-2015-1499
Resumo
International agreements on global warming identify an urgent need for a technology that captures and sequesters carbon dioxide (CO2) in large scale, in order to reduce anthropogenic CO2 emissions into the atmosphere. Among all CCS technologies (Carbon Capture and Storage), mineral sequestration is the most promising. This technology converts CO2 into an environmentally stable solid carbonate. Thus, many researches are being elaborated using Life Cycle Assessment (LCA) in order to assess the energy requirement and the CO2 emissions derived from all stages involved in the mineral sequestration process, starting from the mining of raw materials until the final disposition of the products. In this work, the quantity and quality of raw materials available in Brazil to perform a mineral sequestration process were determined. Two scenarios were analyzed, assessing two types of mineral sequestration process: by strong acids and ammonium salts, respectively, oriented to capture the CO2 emissions from power plants fueled with coal. The energy requirement was based on exergetic analyses while the environmental analyses were based on the Life Cycle Assessment (LCA). The results show that the best mineral raw material is the serpentine (1.9 tserpentine and 2.3 tserpentine were used for strong acid and ammonium salts, respectively). The mineral sequestration stage is the most critical one because it takes larger quantities of energy, principally for the regeneration of chemical inputs (i.e. 3.4 MW and 1.2 MW for strong acid and ammonium salts, respectively). However, the mineral sequestration by ammonium salts is the most promising, thus it can produce around 3.14 t and 0.91 t of carbonates and SiO2 per each tCO2 fixed, respectively. Moreover, the quantity of CO2 avoided by ammonium salts process was 0.54 t of CO2.
Palavras-chave: carbon capture; mineral carbonation; carbon dioxide; exergetic assessment