Experimental determination of dissociation temperatures and enthalpies of methane, ethane and carbon dioxide hydrates up to 90 MPa by using a multicycle calorimetric procedure

Autor(es)

Dolores Robustillo, Maria ^{[1, 2]} ; Sanches de Menezes, Davi Eber ^{[1, 3]} ; Pessoa Filho, Pedro de Alcantara ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Engn Sch, Dept Chem Engn, Av Prof Luciano Gualberto 380, BR-05508010 Sao Paulo, SP - Brazil

^[2] Univ Politecn Madrid, Dept Ingn Quim Ind & Medio Ambiente, Escuela Tecn Super Ingn Ind, Jose Gutierrez Abascal 2, Madrid 28006 - Spain

^[3] Univ Campinas UNICAMP, CEPETRO FEM, POB 6052, BR-13083896 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: FUEL; v. 312, MAR 15 2022.
• Citações Web of Science: 0

Resumo

This work presents the application of a multicycle procedure to determine the dissociation temperature and enthalpy of gas hydrates using high-pressure microcalorimetry (HP-mu DSC). In the multicycle procedure, a sample of water in contact with the gas undergoes successive cooling and warming cycles below hydrate dissociation temperature, increasing the conversion of water into hydrate. This technique has been previously used in literature to increase water conversion during carbon dioxide hydrate formation up to 2.0 MPa, but its applicability has not been assessed for higher pressures and with different guest molecules. New experimental equilibrium data for methane, ethane, and carbon dioxide hydrates were obtained through HP-mu DSC up to 90 MPa using the multicycle procedure. The advantages and limitations of the method are discussed. Dissociation temperatures are in good agreement with data previously obtained from a HP-mu DSC standard method, which confirms the reliability to determine this property by both methods. Nevertheless, the enthalpy of hydrate dissociation obtained by the direct integration of thermograms provided by the HP-mu DSC standard method is not accurate. Thus, it is usually calculated by using the Clapeyron equation from equilibrium temperature and pressure data obtained by the HP-mu DSC standard method, as presented in previous work. The new dissociation enthalpies presented in this work were obtained experimentally by direct integration of thermograms using the multicycle procedure, which provides accurate data as the conversion is very high (above 97% of water converts into hydrate), the baselines are clearly established, and no exothermic peak related to metastable phases is observed. (AU)

• Processo FAPESP: 14/25740-0 - Estudo da formação e dissociação de hidratos de gás em altas pressões
• Beneficiário: Maria Dolores Robustillo Fuentes
• Modalidade de apoio: Bolsas no Brasil - Jovens Pesquisadores
• Processo FAPESP: 14/02140-7 - Estudo da formação e dissociação de hidratos de gás
• Beneficiário: Maria Dolores Robustillo Fuentes
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 15/23148-9 - Estudo termodinâmico da formação e dissociação de hidratos de gás
• Beneficiário: Davi Éber Sanches de Menezes
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto