Thermal decomposition kinetics of Brazilian limestones: effect of CO2 partial pressure

Autor(es)

Avila, Ivonete ^{[1, 2]} ; Crnkovic, Paula M. ^[1] ; Milioli, Fernando E. ^[1] ; Luo, Kai H. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sch Engn Sao Carlos, Grp Thermal & Fluids Engn, Sao Carlos, SP - Brazil

^[2] Univ Southampton, Sch Engn Sci, Energy Technol Res Grp, Southampton, Hants - England

• Tipo de documento: Artigo Científico
• Fonte: ENVIRONMENTAL TECHNOLOGY; v. 33, n. 10, p. 1175-1182, 2012.
• Citações Web of Science: 8

Resumo

The influence of the partial pressure of carbon dioxide (CO2) on the thermal decomposition process of a calcite (CI) and a dolomite (DP) is investigated in this paper using a thermogravimetric analyser. The tests were non-isothermal at five different heating rates in dynamic atmosphere of air with 0% and 15% carbon dioxide (CO2). In the atmosphere without CO2, the average activation energies (E-alpha) were 197.4 kJ mol(-1) and 188.1 kJ mol(-1) for CI and DP, respectively. For the DP with 15% CO2, two decomposition steps were observed, indicating a change of mechanism. The values of E-alpha for 15% CO2 were 378.7 kJ mol(-1) for the CI, and 299.8 kJ mol(-1) (first decomposition) and 453.4 kJ mol(-1) (second decomposition) for the DP, showing that the determination of E-alpha for DP should in this case be considered separately in those two distinct regions. The results obtained in this study are relevant to understanding the behaviour changes in the thermal decomposition of limestones with CO2 partial pressure when applied to technologies, such as carbon capture and storage (CCS), in which carbon dioxide is present in high concentrations. (AU)

• Processo FAPESP: 08/54062-9 - Correlação da efetividade de reação com a evolução da estrutura física de calcários na sulfatação
• Beneficiário: Ivonete Ávila
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado