Data/hora: 02/06/2024 16:49:59

Provedor de dados: 	Institutional Archive of Ifreme (ArchiMer)	
País: 	France	
Título: 	X-ray synchrotron diffraction study of natural gas hydrates from African margin - art. no. L22303	
Autores: 	Bourry, Christophe; Charlou, Jean-luc; Donval, Jean-pierre; Brunelli, M; Focsa, C; Chazallon, B.	
Data: 	2007-11	
Ano: 	2007	
Palavras-chave: 	Synchrotron X ray diffraction; Thermal expansion; Natural clathrate hydrates.	
Resumo: 	Natural gas hydrates recovered from the Congo- Angola basin and Nigerian margins are analyzed by synchrotron X- ray powder diffraction. Biogenic methane is the most abundant gas trapped in the samples and others minor components (CO2, H2S) are co-clathrated in a type I cubic lattice structure. The refinement for the type I structure gives lattice parameters of a = 11.8646 ( 39) angstrom and a = 11.8619 ( 23) angstrom for specimens from Congo- Angola and Nigerian margins respectively at 90 K. These values, intermediate between the lattice constant of less pure methane specimens and pure artificial methane hydrates, indicate that lattice constants can be affected by the presence of encaged CO2, H2S and other gas molecules, even in small amounts. Thermal expansion is also presented for Congo- Angola hydrate in the temperature range 90 - 200 K. The coefficients are comparable with values reported for synthetic hydrates at low temperature and tend to approach thermal expansion of ice at higher temperature.	
Tipo: 	Text	
Idioma: 	Inglês	
Identificador: 	http://archimer.ifremer.fr/doc/2007/publication-3511.pdf

DOI:10.1029/2007GL031285	
Editor: 	American Geophysical Union	
Relação: 	http://archimer.ifremer.fr/doc/00000/3511/	
Formato: 	application/pdf	
Fonte: 	Geophysical Research Letters ( GRL ) (0094-8276) (American Geophysical Union), 2007-11 , Vol. 34 , N. 22 , P. NIL_46-NIL_50	
Fonte: 	2007 by the American Geophysical Union