Estudo da interação CO2-rocha-fluido no processo de carbonatação de aqüíferos salinos

• Ano de defesa: 2010
• Autor(a) principal: Schütz, Marta Kerber
• Orientador(a): Ligabue, Rosane Angélica
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Pontifícia Universidade Católica do Rio Grande do Sul; Porto Alegre
• Palavras-chave em Português: ENGENHARIA DE MATERIAIS; CAPTURA DE CARBONO; AQUÍFEROS; CARBONATOS; DIÓXIDO DE CARBONO
• Link de acesso: http://hdl.handle.net/10923/3353

The climate change caused by anthropogenic emissions of greenhouse gases in the atmosphere, mainly carbon dioxide (CO2), is a current concern, being necessary the reduction of the concentration of these gases. The geologic carbon storage is a promising technology in the reduction CO2 to the atmosphere. Among the storage options, saline aquifers have the greatest potential owing to their common occurrence at appropriate depths and great capacity of storage. Furthermore, the saline aquifers have high salinity groundwater, being improper for human consumption. Therefore, this work aims to experimentally study the CO2 brine-rock system, in different conditions (mild and supercritical), aiming to establish best reactions conditions and, consequently, a bigger efficiency in the geologic carbon storage. The results showed that the carbonation reactions in mild conditions are selective for calcium ion (Ca+2), favoring the predominant precipitation of calcium carbonate (CaCO3). The precipitation was only achieved by adjusting the pH of the brine with alkaline additives sodium hydroxide (NaOH) 1M and potassium hydroxide (KOH) 1M associated with buffer solution of ammonium chloride/ammonium hydroxide (NH4Cl/NH4OH). The results of the carbonation reactions in supercritical conditions, which were used the same alkaline additives and buffer solution, showed that, without the presence of rock, the precipitation of CaCO3 is also predominant. On the other hand, when there is the presence of rock, occurs the precipitation of magnesian calcium carbonate (CaCO3(Mg)) or calcium magnesium carbonate (CaMg(CO3)2). The reservoir rock used in this study showed mineralogical integrity front of the addition of CO2 indicating its potential for geological storage of CO2.